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Scientific Journal Published by the
College of Dentistry – University of Baghdad
Vol. 24 No. 2 2012
ISSN
ISSN
1680-0087
A quarterly peer reviewed published scientific journal of the College of Dentistry,
University of Baghdad.
Editor in chief: Prof. Dr. Nabil Abdulfatah Hatoor, M.Sc
Vice editor in chief: Prof. Dr. Hussain Faisal Al-Huwaizi M.Sc., PhD
National Members
International Members
Prof. Dr. Adel Farhan MSc
Prof. J. L. Gutmann D.D.S., Ph.D.(USA)
Prof. Dr. Zainab Al-Dahan MSc
Prof. Dr. M. Goldberg PhD (France)
Prof. Dr. Abbas Sabri M.Sc., PhD
Prof. Dr.Wasan Hamdi M.Sc, PhD
Assist. Prof. Dr. Leka’a Mahmood M.Sc
Assist. Prof. Dr. Sabah Nema M.Sc., PhD
Prof. Dr. Nidhal Hussain MSc
Assist. Prof. Dr. Sahar Shaker MSc
Assist. Prof. Dr. Ghassan Abdulhameed
MSc
Board of editorial consultants:
1- Prof. Dr. Majida Al-Hashimi MSc
5- Prof. Dr. Shatha Saleem MSc
2. Prof. Dr. Akram Al-Huwaizi MSc, PhD
6- Assist. Prof. Dr. Maha Shukri MSc
3- Prof. Dr. Mohammad Al-Qaisi MSc
7- Assist. Prof. Dr. Abbas Fadhil PhD
4- Prof. Dr. Raja Hadi MSc, PhD
8- Lecturer Dr. Jamal Abid MSc
Secretarial committee:
1- Lecturer Dr. Mohammad Nahidh
2- Lecturer Yassir AbdulKadum
3- Assist. Lecturer Ahmed Fadhil
4- Assist. Lecturer Ayad M. Al-Obaidi
For consultation, please contact:
Website: www.codental.uobaghdad.edu.iq
E-mail: baghdad_dentistry@yahoo.com
Telephone: (+9641)4169375 Fax: (+9641)4140738
i
Contents
i
Editor and Editorial Board
ii
Contents
v
Instructions for the Authors
Restorative Dentistry
1
Effect of different metal surface treatments and thermocycling on shear bond strength of heat cure and
light cure at Co/Cr and Ni/Cr interface. Ali M. Khursheed, Salah A. Mohammed.
6
Comparison of certain mechanical properties including deflection fatigue resistance of Cobalt Chromium
alloy & Nylon tooth colored clasping materials. Azhar Imran Majeed Al-Awady, Widad Abdul-Hadi AlNakkash
11
A comparison of the retention of complete denture bases having different types of posterior palatal seal
with different palatal forms. Mayada Qasim Abdul Khafoor
18
An evaluation of the use different techniques of the thermoplasticized obturators on the coronal seal
Mervat M. Al-Bakri, Hussain F. Al-Huwaizi
21
An evaluation of apical microleakage in roots filled with thermoplastic synthetic polymer based root
canal filling material (RealSeal 1 bonded obturation). Nadine J. Adbul-rada, Adel F. Ibraheem
27
The effect of two types of disinfectant on shear bond strength, hardness, roughness of two types of soft
liners. Rola W. Abdul-Razaq
Oral Diagnosis
32
Immunohistochemical detection to evaluate the biological role of Ti implants coated by a combination of
fibronectin protein and hydroxyapitate (EPD) (in vivo study). Athraa Y.Al-Hijazi, Thair L-Al-Zubaydi,
Eman Issa Mahdi
39
Evaluation of 900 mhz mobile phone effects on palate and tooth germ development in mouse embryo
(histological & immunohistochemical study). Faten H. Berto, Athraa Y. Al-Hijazi
47
Chronological ِage estimation in adolescent and young adult subjects in relation to mandibular third
molar development using digital panoramic image. Jaafar J. Attar, Jamal Ali AL-Taei
51
Diagnosis of the angular hyperkeratotic lesions and the incidence of the etiologic factors. Jamal N.
Ahmed
ii
56
Pre-implant computed tomography and insertion torque measurement in qualitative determination of
trabecular bone density. Mahmood J. Hamzah, Jamal A. Al-Taei
62
Evaluation of oral health status in a sample of autistic male children. Mayyadah H. Rashid, Raja H. AlJubouri
66
Ovulation detection through salivary levels of sialic acid and glycosaminoglycans. Rand M. Al-khafagy,
Sahar H. Al-Ani, Ali Y.Majid
70
Temporomandibular disorders in association with stress among students of sixth grade preparatory
and students of fifth year high schools. Toka T. Alnesary, Rafil H. Rasheed
75
Histological evaluation of osseointegration around titanium implants in thyroidectomized rabbits
(experimental study). Zaid Muwafaq Ali, Nada Mohammed Hasan Al-Ghaban
Prevalence of pulp stone (Orthopantomographic-based). Zainab H. Al-Ghurabi, Areej A. Najm
80
Oral and Maxillofacial Surgery and Periodontology
85
Evaluation of the haemostatic action of povidone- iodine in dental extraction (Clinical and follow up
prospective study). Ali Qays Lilo Al-Amiri
88
A comparison between the antibacterial and antifungal effects of chlorhexidine digluconate (An in
vitro study). Firas H. Qanbar
Orthodontics, Pedodontic, and Preventive Dentistry
91
Effect of in-dental clinic bleaching agents on the releases of mineral ions from the enamel surfaces in
relation to their times intervals. Afnan Al-Shimmer, Mohammad Al-Casey
94
Physicochemical characteristic of unstimulated and stimulated saliva with different chewing gum
stimulation. Alhan A. Qasim, Eman K. Chaloob.
99
Dynamic lip to tooth relationship during speech, posed and spontaneous smile using digital
videography. Ali S. Al-khafaji, Nagham M. Al-Mothaffar
104
Dental caries in relation to oral infections and feeding types among children aged 2-5 years. Aseel
Haidar M.J. Al-Assadi
109
The staining effect of chlorhexidine mouthwash on non metallic brackets (An in vitro comparative
study). Hayder J. Attar, Fakhri A. Ali
114
Tooth attrition patterns in a group of Iraqi adults sample with different classes of malocclusion (A
comparative study). Issam M. Abdullah, Ausama A. Al- Mulla
120
Clinical significance of sella turcica morphologies and dimensions in relation to different skeletal
patterns and skeletal maturity assessment. Kasim A. Obayis, Ali I. Al-Bustani
iii
127
Clinical performance comparison of a clear advantage series II durable retainer with different
retainers' types. Mustafa M. Al-Khatieeb
137
Stimulation of rabbit condyle growth by using pulsed therapeutic ultrasound (A radiographical and
histological experimental study). Mustafa A.Qaisi, Nidhal H. Ghaib
144
The relation between W angle and other methods used to assess the sagittal jaw relationship. Sara M.
Al-Mashhadany
150
A comparative study evaluating the microleakage of different types of restorative materials used in
restoration of pulpotomized primary molars. Zainab A. Al-Dahan, Aseel I. Al- Attar, Huda E.A. AlRubaee
155
Oral health status among a group of pregnancy and lactating women in relation to salivary
constituents and physical properties (A comparative study). Zinah M. Taqi Issa, Sulafa K.El-Samarrai
iv
Instruction for the Authors
The Journal of the College of Dentistry accepts manuscripts that address all topics related to
dentistry. Manuscripts should be prepared in the following manner:
Typescript. Type the manuscript on A4 white paper, with page setup of 2.5 cm margins. Type the
manuscript with English language font Times New Roman and the sizes are as follows:
1) Font size 18 and Bold for the title of the manuscript.
2) Font size 14, Bold and capital letters for the headings as ABSTARCT, INTRODUCTION,
MATERIALS AND METHODS, RESULTS and REFERENCES.
3) Font size 12 Bold and italic for the names and addresses of the authors ex. Ahmed G. Husam
4) Font size 11 for the legends of the tables and figures.
5) Font size 10.5 for the text in the manuscript.
6) Font size 10 for the text inside the tables.
7) Font size 9 for the references at the end of the manuscript.
Use single spacing throughout the manuscript and numbering of the pages should be in the lower
right hand corner.
Title of the manuscript:
The title should be written with a capital letter for the first word as (Effect of the retention and
stability….etc).
Abstract and key words. The abstract should contain no more than 250 words. The abstract should be
divided to the following categories: Background: (It contains a brief explanation about the problem
for which the research was done as well as the aim of the study), Materials and methods:, Results:,
and Conclusion:. Below the abstract, write 3-5 key words that refer as close as possible to the article.
The abstract should be written by the font Century Gothic size 8.
Text. The body of the manuscript should be divided into sections preceded by the appropriate major
headings (INTRODUCTION, MATERIALS AND METHODS, RESULTS and REFERENCES)
which are written in bold and capital. Minor headings should be typed in bold and subheadings should
be not bold but underlined.
References. References are placed in the text using the Vancouver system (Numbering system).
Number references consecutively in the order in which they are first mentioned in the text. Identify
references in the text, tables, and figures by Arabic numerals, and place them in parentheses within the
sentence as superscription ex. (2).
Use the style of the examples given below in listing the references at the end of the manuscript:
Book
1. Hickey JC, Zarb GA, Bolender CL. Boucher’s prosthodontic treatment for edentulous patients. 9th
ed. St. Louis: CV Mosby; 1985. p.312-23.
Journal article
4. Jones ER, Smith IM, Doe JQ. Occlusion. J Prosthet Dent 1985; 53:120-9.
Tables. All tables must have a title placed above the table. Identify tables with Arabic numbers (e.g.
Table 1). The tables should be done with a width of no more than 8 cm.
Figures and illustrations. All figures must have a title placed below the figure. Identify figures with
Arabic numbers (e.g. Figure 1). The figures should be done with a width of no more than 8 cm.
The article should not exceed 7 pages. The author should submit three copies of the article (one
original and two copies) and a (CD) containing the article.
v
J Bagh College Dentistry
Vol. 24(2), 2012
Effect of different metal
Effect of different metal surface treatments and
thermocycling on shear bond strength of heat cure and
light cure at Co/Cr and Ni/Cr interface
Ali M. Khursheed , B.D.S. (1)
Salah A. Mohammed, B.D.S., M.Sc. (2)
ABSTRACT
Background Optimum bond strength at the metal – resin interface of prosthesis is essential for the success of that
prosthesis. The junction between metal alloy and acrylic resin is an area of clinical concern .Failure of a R.P.D. may
be linked to this interface. The main objective of this study were to determine the effect of different metal surface
treatment and thermocycling on the shear bond strength of Co/Cr alloy and Ni/Cr alloy to heat cure acrylic resin
and light cure acrylic resin.
Materials and methods: 120 metal samples were prepared, 60 Co/Cr samples and 60 Ni/Cr of square flat plate (30
mm x 30mm x 2 mm) that incorporated a central area (8mmx 12mm) of a large retentive mesh to simulate denture
framework. The samples were cleaned, finished and electropolished. Sixty samples of each type of metals were
divided into two groups according to the type of acrylic resin received each one 30 samples (A and group C) for
heat cure, B and group D for light cure) which were furtherly subdivided according to the type of surface treatment
into 3 subgroups each one 10 samples(A1 ,B1 ,C1and D1 )for no surface treatment, no thermocycling as a control
group (A2, B2 ,C2 and D2 )for Metal Prime II application with thermocycling (A3, B3 ,C3 and D3) for combination of
Air Abrasion and Metal Primer II application with thermocycling. The acrylic block were then prepared as a
rectangular block(12mm length ,8 mm width ,6 mm high )that was placed on a central area of metal plates, the
acrylic was fabricated in the same conventional way of denture construction. All the sample were mounted on
specially test fixture that would hold them rigid at a 90-degree angle from the horizontal plane of the crosshead of
the Instron machine .A tangent shear force was created by applying vertical load to the specimen .All of the
specimen were tested with Instron machine using stainless steel chisel shaped road at a constant crosshead speed of
5 mm min until failure of the bond occurred The specimen were stressed to failure .The force of bond failure was
recorded in Newton, which was divide by the surface of the bonded area (96 mm2 )to obtain the shear bond
strength calculated in Mpa.
Result: The results showed that the subgroup that received no surface treatment and without thermocycling for both
two type of resins heat cure and light cure (A1, B1, C1and D1) had the highest shear bond values, followed by
subgroups that received Air Abrasion + Metal Primer II surface treatments and thermocycling (A3, B3, C3,
D3).Subgroups that received Metal Primer II alone (A2, B2, C2 and D2) showed the least shear bond value than the
other subgroups.
Conclusion: All metal samples of Co/Cr and Ni/Cr with heat cure acrylic resin showed higher SBS mean values than
that light cure resin whether with surface treatment and thermocycling or without thermocycling concluded higher
binding of heat cure acrylic resin with the metal surface.
Keywords: Co/Cr-heat and light cure resin interface, Ni/Cr- heat and light cure resin interface ,metal surface
treatment,shear bond strength. (J Bagh Coll Dentistry 2012;24(2):1-5).
The actual bonding mechanism of metal to resin
framework has had many recent modifications
with three basic systems used (1-3). (1)
Mechanical Retention System; this system is
subdivided into; (a) Macromechanical retention
system retention which involves different
techniques (retentive element technique, pitting
corrosion technique); (b) Micromechanical
retention system which involves (air particle
abrasion, electrolytic etching and chemical
etching. (2) Chemical retention system which is
applied through (oxidation technique, tin plating
and adhesive agents).
(3) Mechanical/Chemical retention system this
system was achieved by a combination of
mechanical and chemical retention techniques ,the
most widely used technique in this system is
silicoating technique which produced several
systems other than conventional silicoater
INTRODUCTION
The bond strength of the metal-resin interface
of a prosthesis it is a key factor in determining
the serviceability of that prosthesis (1). The bond
between the metal surface of a prosthesis
framework and the acrylic denture base that it
supports has been a concern of clinician, if there
is separation between these two materials,
especially at the junction referred to as the
external finishing line, the crack in that area
become a haven for microorganisms and plaque
accompanied by staining. So a stable bond
between the metal and resin should exist to
prevent
microleakage
and
subsequent
unfavorable results.
(1) MSc student, Department of Prosthetic Dentistry, College of
Dentistry, Baghdad University
(2) Assistant Professor, Prosthodontic department, College of
1
Vol. 24(2), 2012
type of surface treatment that will be performed.
A group of 40 samples (A1,B1,C1,D1) receive no
surface treatment and no thermocycling for
controlling purposes .Another 40 samples (A2,
B2,C2, D2) were subjected to metal primer II
pretreatment and thermocycling ,the last 40
samples were subjected to a combination of air
abrasion and Metal Primer pretreatment with
thermocycling (A3, B3 ,C3,D3).
Application of acrylic resin to grouping
samples
The metal samples receiving HCR, a special mold
was made from brass to reproduce the wax pattern
which were rectangular block (12mm length
,8mm width ,and 6 mm height ) ,the wax was
melted in a small stainless steel container by using
electrical thermo- mat at 10 degree and poured
inside metal mould ,then these block were sealed
in the central area of metal sample ( 8mm X
12mm) .The conventional flasking procedure for
acrylic denture construction was followed , for the
second subgroups; after wax elimination and
before packing of acrylic resin, 2-3 drops of Metal
Primer II were dispensed into a dappen dish or
similar container, and then applied as a thin layer
to the central mesh area of metal sample. The
acrylic resin was applied to the treated surface
after 5 seconds according to manufacturers
instructions.
including (Silicoater MDSystem, Rocatec System
and Kevloc System (4) .This study was designed to
evaluate the effect of different types of metal
surface treatments on shear bond strength of two
types of acrylic resins (heat cure and light cure).
Metal Primer II (GC Corp, Tokyo, Japan), which
contains a special functional monomer
methacryloyloxyalkyl
thiophosphoric
methacrylate (MEPS) which promotes bonding by
penetrating the metal alloy due to presence of
phosphate group that presents chemical bonding
with the surface layer of oxide of chrome formed
in the surface of Co/Cr, which can reliable to
promote better union of with metal, in addition,
Metal Primer II forming co-polymerizing with the
resin to produce both a mechanical and chemical
bond to metal surface (5-6) .
MATERIALS AND METHODS
120 samples were prepared by using metal mold
constructed and designed to reproduce wax
patterns with modeling sheet wax( Dentaurum,
Germany ) which was a rectangular plate (30 mm
X 30 mm X 2 mm) that incorporated a central
area (8mm X 12mm). On the upper surface there
is a metal handle which facilitate holding of the
mold during wax patterns procedure. The wax
pattern was sprued ,investd (Rema R Exakt,
Dentaurum, Germany) and cast in CobaltChromium alloys (Remanium R Gfh, Dentaurum,
Germany),and Nickle-Chromium alloys (CB
BLANDO 72 ,Hatakeyama Dental MFG, Japan
).Each sample was cleansed from investment
material and electropolished for 12 minutes to
produces samples with a brilliant finished surface
Figure 2: Application of metal primer to
metal sample which received heat cure
acrylic resin
For third subgroups, the sample was treated first
with air abrasion by using laboratory air abrasive
blaster with 250 µm aluminum oxide at air
pressure of 4 to 6 bar for 1 minute, the samples
were held with a specially designed fixture for
standardization of the distance between the metal
surface and the nozzle of the device (20 mm),all
the metal samples that receive HCR were trimmed
,smoothed and polished.
The metal samples receiving VLCR were
treated with a chemical bonding agent that was
applied by brush to the central area of the metal
samples which are now ready for light cure resin
application, it was directly applied resin to metal
sample .No flasking procedure is needed.
Figure 1: Finished and electropolished metal
samples
This study consisted of 120 samples prepared by
divided into two groups according to the type of
metal used .Group {A}&{C} refers to the metal
samples that will receive heat-cure clear acrylic
resin(HCR), while group {B}&{D} refers to
metal samples that will receive light cure acrylic
resin(VLCR). Samples of each group were then
furtherly subdivided into three groups; each one
consists of 10 metal samples, according to the
2
Vol. 24(2), 2012
Each sample was thermocycled for 3000 cycles in
distilled water each cycle at 5°C to 50°C with a
dwell time of 1 minute, the 3000 cycles were done
within 10 days by divided the thermocycling
procedure into 300 cycles per day, all the sample
were mounted on specially test fixture that would
hold them rigid at a 90-degree angle from the
horizontal plane of the crosshead of the instron
machine
A tangent shear force was created by applying
vertical load to the specimen .All of the specimen
were tested with instron machine using stainless
steel chisel shaped road at a constant crosshead
speed of 5 mm min until failure of the bond
The specimen were stressed to failure .The
force of bond failure was recorded in Newton,
which was divide by the surface of the bonded
area (96 mm2 )to obtain the shear bond strength
calculated in Mpa.
Figure 3: Finished Metal Samples with Heat
Cure Acrylic Resin (Group A ,C).
Figure 4: Application of Metal Primer II for
Light Cure Acrylic resin
For the light cure acrylic resin the sheets of
acrylic are ready to apply directly without any
preparation or mixing like heat cure acrylic resin.
For the curing of light cured specimens a special
glass mould (12cm ×12cm) contains the same
dimensions and angulations of the rectangular
block was designed The glass mould contains
rectangular block and has two glass covers upper
and lower in order to permit for two sided curing
in the light curing device and perforated with four
openings for the tightens of the two glass covers
with metals bolts in order to provide firm pressure
during curing, the metal bolts were placed in their
position and then they were tightened by using
wrench and tightened for only one click for
standardization.
After adaptation of light cure acrylic, then cured
with light cure unit (Yeti-Dental, Germany) at 400
to 500 nm wave length for 10 minutes {as
manufacturer
instructions}
and
After
polymerization, the samples were trimmed,
smoothened and then polished.
Figure 6: The vertical load applied using
stainless steel chisel shaped rod
RESULTS
The result of this study were collected and
analyzed statistically. Mean, standard deviation,
minimum and maximum values of shear bond
strength in Mpa of all groups are presented in
tables 1&2.
Source of differences was investigated by further
complement analysis of data (Least Significant
Difference, LSD test) to examine the difference
between difference pairs of the three groups as
shown in Tables 3&4 , where group {A}&{C}
refers to the metal samples that will receive heatcure clear acrylic resin, while group {B}&{D}
refers to metal samples that will receive light cure
acrylic resin. Samples of each group were then
furtherly subdivided into three groups; each one
consists of 10 metal samples, according to the
type of surface treatment that will be performed.
A group of 40 samples (A1,B1,C1,D1) receive no
surface treatment and no thermocycling for
controlling purposes .Another 40 samples (A2,
B2,C2, D2) were subjected to metal primer II
pretreatment and thermocycling ,the last 40
samples were subjected to a combination of air
Figure 5: Light cure Acrylic Resin (Group B,
D) after Curing
3
Vol. 24(2), 2012
samples of Heat cure Acrylic Resin-metal
interface, because the effect of air abrasion raised
mean bond strength values than that of only metal
primed subgroup , the effect of the Air Abrasion
on the bond of metal to resin could be explained
that when the particles of Air Abrasion hit the
metal surface and their kinetic energy is
transformed to thermal energy, which may reach
the melting point of metal alloy. The melting of
the metal alloy is limited to 1 or 2 µm from the
surface.
abrasion and Metal Primer pretreatment with
thermocycling (A3, B3 ,C3,D3).
DISCUSSION
In the present study, shear bond strength of metalresin interface was evaluated , the specimen were
held at 90 degree so that the direction of the force
applied to the specimen was vertical. All of the
specimen were tested with instron machine using
stainless steel chisel shaped road at a constant
crosshead speed of 5 mm min until failure of the
bond occurredAll the specimens were prepared
using standard laboratory methods commonly
used for clinical prosthesis and the specimen
groups that received no more than the
conventional macromechanical retention system
which represented by the large mesh and without
thermocycling, was prepared as control group
Many studies showed that there is an increase in
the bond strength of the metal resin interfaces
when the alloy is treated with various metal
surface treatments
Effect of Different metal Surface Treatments
on SBS for Light cure Acrylic Resin-Metal
interface
This study show that the SBS mean values of
metal primed and thermocycled of the Light Cure
Resin-Metal interface less than subgroup that
were not subjected to surface treatment and
without thermocycling Since thermocycling cause
hydration of the specimens, so this will leads to
decreasing the shear bond strength after
thermocycling, Also, the water sorption of VLC
were found to be greater than that of the other
types of acrylic resin, so the material absorbed
water and this had a damaging effect on the
bonding.
This study also show that the SBS mean values of
metal primed ,air abraded and thermocycled
samples of the Light Cure Resin-metal interface
less than subgroup that were not subjected to
surface treatment and without thermocycling ,yet
it was higher than metal primed and thermocycled
samples of Heat cure Acrylic Resin- metal
interface subgroup, because the effect of air
abrasion raised mean bond strength values than
that of only metal primed subgroup,this might be
due to the result of the combination of
micromechanical retention that was achieved by
the Air Abrasion and chemical retention that was
achieved by the Metal Primer II which provided
adhesive bridges between the metal surface and
resins (heat cure or VLC resins), the effect of the
air abrasion on the bond of metal to composite
resin could be explained by increasing the surface
area of alloy surface ,expanding the energy of the
alloy and also highest the activity of the surface of
alloy. The effect of air abrasion particle results in
deposition of molecular coating of alumina and
silica on the metal surface.
Air Abrasion with aluminum oxide on the surface
of cobalt-chromium alloy favors the bonding
between the chrome oxide and resin. Moreover,
Air Abrasion promotes formation of surface
irregularities on the metal, achieving micromechanical bonding when resin flows through
these irregularities.
Effect of Different metal Surface Treatments
on SBS for Heat cure Acrylic Resin-Metal
interface
This study shows that the SBS mean values of
metal primed and thermocycled of the Heat Cure
Resin-metal interface less than subgroup that were
not subjected to surface treatment and without
thermocycling ,this results may be explained by
the reaction with water, such as swelling of the
acrylic resin due to water sorption, stresses
resulting from the difference in the coefficient of
thermal expansion, thermocycling speed up the
diffusion of water in between resin and metal,
Metal Primer II (chemical bonding agent)
increased SBS between the metal and both two
types of acrylic resins (heat and VLC). Metal
Primer II (GC Corp, Tokyo, Japan), which
contains a special functional monomer
methacryloyloxyalkyl
thiophosphoric
methacrylate (MEPS) which promotes bonding by
penetrating the metal alloy due to presence of
phosphate group. This group presents chemical
bonding with the surface layer of chrome oxide
formed in the surface of Co/Cr, which is reliable
to promote better union with metal, in addition,
Metal Primer II lead to co-polymerization with
the resin to produce both a mechanical and
chemical bond to metal surface ,also this study
show that the SBS mean values of metal primed
,air abraded and thermocycled samples of the
Heat Cure Resin-metal interface less than
subgroup that were not subjected to surface
treatment and without thermocycling yet it was
higher than metal primed and thermocycled
4
Vol. 24(2), 2012
4. Pesun S, Mazurat R. Bond strength of acrylic resin to
cobalt-chromium alloy treated with the silicoater MD
and Kevloc systems. J Can Dent Assoc 1998; 64:798802.
5. Freitas AP, Francisconi PAS. Effect of a metal primer
on the bond strength of the resin-metal interface. J
Appl Oral Sci 2004; 12(2):113-6.
6. Silveria de Araujo C, Incerti Da Silva T, Ogliari FA,
Meireles SS, Piva E, Demarco FF, Microlekage of
seven adhesive system in enamel and dentine. J
Contemp Dent Pract 2006; 5(7):26-33.
REFERENCES
1. Sharp B, Morton D, Clark A.E. Effectiveness of metal
surface treatments in controlling microleakage of the
acrylic resin-metal framework interface. J Prosthet
Dent 2000; 84:617-622.
2. Ohkubo C, Watanabe I., Hosoi T, Okabe T. Shear
bond strengths of polymethyl methacrylate to cast
titanium and cobalt-chromium frameworks using five
metal primers. J Prosthet Dent 2000; 83:50-7
3. Kim JY, Pfeiffer P, Niedermeier W. Effect of
laboratory procedures and thermocycling on the shear
bond strength of resin-metal bonding systems. J
Prosthet Dent 2003; 90:184-9.
Table 1: Mean Shear bond strength (SBS) of subgroups samples at Heat Cure Resin-metal
interface (Group A&C)
Statistical
Analysis
Mean
SD
Min
Max
A1
A2
A3
C1
C2
C3
5.9
1.05
4.6
7.62
4.7
0.9
3.4
6.1
5.1
0.8
3.9
6.3
4.8
1.1
2.4
6.4
4.1
1.3
2.4
6.1
4.1
1.1
2.22
6.17
Table 2: Mean Shear bond strength (SBS) of subgroups samples at Light Cure Resin-metal
interface(Group B&D)
Statistical
Analysis
Mean
SD
Min
Max
B1
B2
B3
D1
D2
D3
4.6
0.9
2.8
6.4
3.3
0.9
2
4.8
3.5
1.3
2
6.4
3.8
0.7
2.6
5.1
2.7
0.9
1.6
4.6
3.1
0.6
2.1
4.1
Table 3: Least significant difference for the Subgroups samples of Heat Cure resin-metal
interface (Group A&C).
(I) (J)
Group Group
A1&A2
A1&A3
A2&A3
C1&C2
C1&C3
C2&C3
P
value
.014
.110
.342
.247
.275
.945
(I-J)
1.148
.7244
-.424
.65100
.6130
-.0380
Significance
S
NS
NS
NS
NS
NS
Table 4: Least significant difference for the Subgroups samples of Light Cure resin-metal
(Group B&D).
(I) (J)
Group Group
B1&B2
B1&B3
B2&B3
D1&D2
D1&D3
D2&D3
(I-J)
P value
1.33
1.13
-.19
1.0
.76
-.31
.01
.03
. 69
.00
.03
.36
5
Significance
S
S
NS
HS
S
NS
Vol. 24(2), 2012
Comparison of certain
Comparison of certain mechanical properties including
deflection fatigue resistance of Cobalt Chromium alloy &
Nylon tooth colored clasping materials
Azhar I.M. Al-Awady, B.D.S., H.D.D., M.Sc.(1)
Widad Abdul-Hadi Al-Nakkash, B.D.S., H.D.D., M.Sc. (2)
ABSTRACT
Background: This study was conducted to test & compare the mechanical properties including the ultimate tensile
strength, yield strength, modulus of elasticity, ductility & deflection fatigue resistance of Cobalt Chromium alloy
samples, Flexite Supreme samples & commercially available Nylon samples, thus evaluating efficiency & life time
expectancy of these materials.
Materials and methods: A reproduction mold was made from addition silicon reproduction material to produce wax
patterns of standardized measures, these sacrificial patterns were used to produce fifty samples of each of the three
materials (a total of 150 samples). These specimens were tested by tensile testing machine and deflection fatigue
resistance machine.
Results: The tested materials expressed differences in their mechanical properties that were highly significant in all
comparisons.
Conclusions: Cobalt Chromium alloy, aside from its poor aesthetic, performs better in shallow deflection and have a
reasonable life expectancy. Flexile supreme is more aesthetically acceptable, with better performance and longer
life expectancy. Commercial nylon is with poor quality rendering it unusable.
Keywords: deflection fatigue, tensile strength testing, Cobalt Chromium, Flexile supreme. (J Bagh Coll Dentistry
2012;24(2):6-10).
These materials generally replace the metal, and
pink acrylic denture used to build the framework
for standard removable partial dentures (4). A
nylon that is suitably stiffened could be extremely
useful in the treatment of those patients for whom
acrylic prostheses are not suitable. This would
include patients who demonstrate repeated
fracture of dentures and those that show tissue
reactions of a proven allergic nature (5). Flexite
Company developed and patented the firs tooth
color clasps known. This product made of a nylon
material (6).
Fatigue testing which is subjecting a test sample
to rapid cycling at a given stress until failure
occurs is considered one of the basic testing
procedures used to provide data for metals and
alloys comparison (7), in addition fatigue is
responsible for 90% of all service failure (8). The
retentive clasp arms are the parts of removable
partial denture most frequently damaged (9,10)
since clasps in clinical use are subjected to cyclic
bending during insertion, removal of partial
dentures and also during mastication (7).
INTRODUCTION
The removable partial denture must have retention
to resist reasonable dislodging forces. Primary
retention of a removable partial denture is
accomplished mechanically by placing retention
elements on the abutment teeth (1).
A direct retainer is any unit of a removable dental
prosthesis that engages an abutment tooth in such
a manner as to resist displacement of the
prosthesis away from basal seat tissue. This may
be accomplished by frictional means, by engaging
a depression in the abutment tooth, or by
engaging a tooth undercut lying cervically to its
height of contour (2).
There are two basic types of direct retainers. One
is the intracoronal retainer, which is cast or
attached totally within the restored natural
contours of an abutment tooth. The other type of a
retainer is the extra coronal retainer, which uses
mechanical resistance to displacement from
components placed on or
attached to the external surface of an abutment
tooth (1). The extra coronal or clasp direct retainer
is used more frequently than attachment (3).
The problems of clasp arm include poor aesthetics
and fracture of clasp arm (1). The application of
nylon like materials in the fabrication of dental
appliances has been seen as an advance in dental
materials.
MATERIALS AND MTHODS
Tensile strength test: an analog of the specific
shape and dimensions of the sample required
(according EN.ISO. 527-2: 1993) was made from
galvanized steel and used for molding a silicon
mold to produce standardized wax patterns from
which samples were made. Thirty samples were
dedicated for this test. Ten samples of Flexite
supreme; group A (Flexite USA) & ten of
(1) Head of the prosthetic department of specialized center of
dentistry, Thi Qar, An-Nasirya.
(2) Professor, department of Prosthetic dentistry, college of
dentistry university of Baghdad.
6
Vol. 24(2), 2012
commercial nylon; group B (made in China) were
injected using a thermoplastic injection system
(KCX-09A, China). The same wax patterns were
used for casting ten Co-Cr samples. All Cobalt
Chromium samples were checked for unforeseen
impurities that may have been hidden below the
outside surface (figure 1). The samples were
seated individually on the X-Ray machine
(Diamax Digivision, Planmeca, Finland) at a
distance of 10 cm. between the sample to be
tested and the radiographic cone was achieved
using the film holder. The X-Ray machine was set
to 70 KV, 10 MA and the exposure time was 0.6
seconds (11-13). All samples that are proven to have
air bubbles or cracks in the testing area (the area
of constriction & not the handles) were discarded.
Deflection fatigue resistance test: the same
procedures for the production of samples were
followed to produce the 120 samples required for
this test (40 samples of each material). The shape
and dimensions of the samples were prepared
according to (ASTM E647/1988). The test was
Figure 2: A polymer specimen clamped by
the jaws of the testing machine after the test
is over by failure in tension.
Figure 1: Cropped picture showing a void in
the testing area of the sample. Samples
showing a defect under X-Ray were
discarded.
The nylon samples were tested using a
tensile testing machine with jaws designed to grip
polymer samples (figure 2). The metal samples
were tested with a tensile testing machine with
jaws designed to grip metal samples (figure 3).
The test was completed by loading the samples till
failure in tension with a head speed of 20mm. per
sec. The values of the tensile strength were
calculated for each test specimen as the force at
failure divided by the cross sectional area
according to the following formula:
Tensile strength = F (N.) / A (mm.²)
Figure 3: A metal specimen clamped by the
jaws of the testing machine after the test is
over by failure in tension.
carried out by screwing the grip of the testing
machine (HSM20, HI-TECH EDUCATION,
England).
The
deflection
values
(0.25mm.;0.5mm.; 1mm.; & 2.1 mm.) were
obtained from the monogram provided with the
manual of the machine. In a dental appliance,
stress reversal is unlikely to occur & the structure
will be stressed in one direction & allowed to
return to zero in each cycle (15) & (16) & in this
study, this stress cycle was used. Each sample was
marked in the center of its length. The deflections
of 0.25mm, 0.5mm, 1mm. and 2.1mm were
measured at this point for all the samples by a dial
gauge with an extended spindle whose tip was
applied to the central point in the upper surface of
the sample (13) & (17). After a sample had been setup
in the testing machine, the sample was fatigued
until fracture or permanent deformation occurred
(figure 4 & 5).
(14)
F: Force at fracture
A: Original cross-sectional area (ASTM
specifications D-638 M, 1986).
The modulus of elasticity (E), were determined
using the method of comparing two different
points on the stress strain curve and then applying
the following formula:
E= δ2- δ1/ Ɛ2- Ɛ1
δ1: stress on the first point
δ2: stress on the second point
Ɛ1: strain on the first point
Ɛ2: strain on the second point
(14)
7
Vol. 24(2), 2012
Figure 4: Samples showing cracks in the area
to be tested.
Figure7: Stress strain curve of test group A
(Flexite supreme) samples under tension.
Figure 5: Propagation of a crack leads to an
eventual sample fracture.
RESULTS
Stress strain curves of the materials were plotted
demonstrating the behavior of the tested material
in tension and as follows:
1. Co-Cr alloy is stiff, brittle but strong (figure
6).
Figure 8: Stress strain curve of test group B
(commercial Nylon) under tension.
For the ultimate tensile strength, yield strength
and modulus of elasticity Co-Cr had the highest
mean values, respectively: 614.14 MPa;
337.84MPa &120.794MPa. While for the
elongation of breakage it had the lowest mean
value of 9.83 %.
and modulus of elasticity Flexite supreme had the
following mean values respectively: 152.2MPa;
148.17MPa & 10.4778 MPa. While for the
elongation at breakage it had the highest mean
value of 198%.
and modulus of elasticity the commercial nylon
had the lowest mean values, respectively:
45.81MPa; 34.73MPa & 5.6153MPa. While for
the elongation at breakage it had the lowest mean
value of 173.64 %.
Multiple group comparisons of mechanical
properties:
By conducting Fisher's least significant difference
test (LSD), to obtain an understanding of the
multiple statistical comparisons among groups.
The results were found to be as follows:
When comparing the Co-Cr with Flexite supreme
test group for yield strength, ultimate strength,
modulus of elasticity and elongation at breakage
the results revealed a statistically high
significance.
Stress
MPa
Strain %
Fig. 6: Stress strain curve of the mean value
of (Co-Cr) samples under tension.
2. Flexile supreme: flexible, ductile and strong
(fig. 7).
3. Commercial nylon: stiff, ductile and weak (fig.
8).
8
Vol. 24(2), 2012
Comparing Co-Cr with commercial Nylon
test groups for yield strength, ultimate
strength,
modulus
of
elasticity
and
elongation at breakage the results revealed a
statistically high significance.
elasticity the results revealed a statistically highly
significant, and as shows in the (table 1).
DISCUSSION
1.
Mechanical properties: The Co-Cr
group registered E & yield strength, which are a
poor feature concerning clasp design (18). While
the Flexite supreme registering yield strength and
modulus of elasticity that are lower than those of
Co-Cr and higher than that of the commercial
nylon , they might represent the ultimate choice of
a material that can flex out of deeper undercut
;thus minimizing the amount of tooth preparations
and the otherwise un necessary loss of healthy
tooth structure, enhancing retention of a
removable partial denture & minimizing the
amount of stress excreted on the abutments .The
amount of stress required to produce the
necessary retention in Flexite Supreme Nylon
clasps is delivered through the increase of bulk of
the clasp, noting that such an increase wouldn't
overload the prosthesis weight; hence Nylon low
density compared to most base metal alloys; nor
affect the aesthetics of the patient; hence the tooth
colored or gingiva colored clasp. The commercial
nylon (made in china) proven to be not functional
because of the weakness of the material , and
lower modulus of elasticity which would require
building a clasp of non acceptable bulk to
compensate for its inherent weakness and
generate enough strength to retain a RPD (19).
This behavioral difference between metal and
polymer could be attributed to the difference in
the microstructure level. Metals have small
building blocks that are well arranged and highly
organized in a dense uniform pattern thus give a
rather predictable mechanical behavior in
temperatures lower than that of melting point,
while that are made up of large strains of polymer
molecules, the smaller molecule of polymers can
be thousands of times larger than that of any
naturally occurring molecules of metal alloys.
Plus the fact that polymers have different sizes of
molecules contributing to its' structure. These
building blocks of polymers are arranged as areas
of well organized molecules (the crystalline state)
surrounded by areas of curved, twisted &
entangled polymer molecules (amorphous state).
The amorphous state is responsible for the
freedom in movement in any direction of the
polymer in temperatures that are considerably
lower that the melting temp (20).
Deflection fatigue: The results of this study for
Co-Cr alloy revealed that the possibility of having
a Co-Cr clasp that is subjected to cyclic bending
without failure fracture is unlikely to take place
even in the minimum deflection of 0.25mm which
is in agreement with previous clinical
Table 1: Fisher's least significance difference
(LSD) analyzing multiple comparisons between
groups
Mean
Difference
Std. Error
Sig.
CoCr
A
189.67000*
.86026
.000 *
B
303.11000*
.86026
.000
A
B
113.44000*
.86026
.000
CoCr
A
461.94000*
.57241
.000
B
568.33000*
.57241
.000
A
B
106.39000*
.57241
.000
CoModulus of Cr
elasticity
A
A
110.31620
*
.29820
.000
B
115.17870*
.29820
.000
B
4.86250*
.29820
.000
CoElongation Cr
A
-188.17000-*
.41083
.000
B
-163.81000-*
.41083
.000
B
24.36000*
.41083
.000
Yield
Strength
.Ultimate
Tensile
strength
A
LSD *. The mean difference is significant at the 0.05 level.
Table 2: mean value of cycles required to
fracture or permanently deform a sample.
Material
A
B
Co-Cr
0.25 mm.
deflection
21272587.5
18795881.1
32210.4000
0.5 mm.
deflection
12128790.7
10673335.7
13346.9
1 mm.
deflection
7818114.4
6108554
865.7
2.1 mm.
deflection
3193095
3045619.7
527.6
Figure 9: A histogram demonstrating a
comparison of the mean values of the
number of cycles required to fracture or
deflect a sample under deflection for the (CoCr) , test group A (Flexite supreme ) and test
group B (Commercial Nylon).
Deflection fatigue resistance test results showed
that Flexite supreme had the highest mean value
at all deflections while the Co-Cr had the lowest
mean values and as shown in table 2 & figure 9.
Comparing the two test groups for yield strength,
ultimate strength and elongation at breakage
recorded a high statistical significance.
Comparing the two test groups for modulus of
9
Vol. 24(2), 2012
observations (10) & other fatigue testing (14,21,7) &
(17)
. This can be attributed to the mechanical
properties of the alloy, mainly the E. the proof
stress (yield strength) & the elongation values. To
explain the results of this study, it seems
important that the E of the metals should be
considered along with the yield strength (proof
stress) property (22). Co-Cr alloys have a high E
which is a poor feature concerning clasp design
but they do have a good proportional limit (18).
Retentive clasp arms are required to have
adequate elasticity to deflect out of the retentive
undercut, adequate stiffness to produce retention
&adequate strength to resist accidental damage
(23)
. The other mechanical property that may affect
the fatigue resistance of a clasp is the ductility of
the material which is usually expressed by the
elongation values, the ductility of Co-Cr alloy is
considered low (brittle material). Co-Cr clasps are
more likely to fracture if bent (24), also increased
ductility of Co-Cr alloy improved the resistance to
fatigue (25).
Differences between the materials (Co-Cr
alloy& Flexite supreme & commercial Nylon)
in deflection fatigue.
The difference in the behavior of the samples of
the three materials at 0.25mm. & 0.5mm. D and
the statistically high significance can be related to
the difference in mechanical properties, especially
the yield strength, which determines the amount
of stress that can build up in the sample (clasp)
when deflected. The high yield strength of Co-Cr
alloy means that the stresses generated due to
deflection can easily pass there proof stress to
cause damage or permanent deformation. While
the lower yield strength of the Flexite supreme
means that considerably lower amount of stress is
generated that don't cause the material to fracture
or deform (26).
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
properties of commonly used denture base resins. J
Prosthodont; 13:17-27.
Morris HF. Asgar K, Tillitson E. "stress relaxation
testing. Part 1: A new approach to the testing of
removable partial denture alloys, wrought wires- &
clasp behavior". J prosthetic Dent 1981; 46(2): 13341.
Zavanelli R, Henriques G, Ferreira H, Almeida Rollo
J. "Corrosion fatigue life of commercially pure
Titanium & Ti-6Al-4V alloys in different storage
environments". J Prosthetic Dent 2000; 84(3): 274-9.
Brockhurst PJ. "A new design for partial denture
circumferential clasp arms". Australian Dental Journal
1996; 41 (5): 317-23.
Harcourt HJ. "Fractures of Cobalt-Chromium
castings". Br Dent J 1961; 1 10(2): 43-50.
Bates JF. "The mechanical properties of CobaltChromium alloys & their Relation to partial denture
design". Br Dent J 1965; 119 (9): 389-96.
Bates JF." Studies related to the fracture of partial
dentures. The functional strain in Cobalt Chromium
dentures , a preliminary report". British Dental Journal
1966;120; 79-83.
Vallittu PK. Luotio K. "Effect of Cobalt-Chromium
alloy surface casting on resistance to deflection fatigue
& surface hardness of Titanium". International Journal
of Prosthodontic 1996; 9 (6): 527-32.
Craig RG. "Restorative Dental Materials", 12
ed.
St Louis: Mosby, 2006; Ch 4: 61-4.
Earnshaw R. "Fatigue tests on dental Cobalt Chromium alloy". Br Dent J 1961: 110(10): 341-5.
Preston JD. "Cobalt-Chromium-Titanium alloy for
removable partial dentures". Int J Prosthodontics
1997;10(4): 309-17
Bridgeman J.T. , Marker VA, Hummel SK, Benson
BW, Pace LL. "Comparison of Titanium & CobaltChromium removable partial denture clasps'! . J
Prosthetic Dent 1997; 78 (2): 187-93.
18. Bates JF. "Retention of partial dentures". Br Dent J
1980; 149: 171-4.
19. Kaplan 2008. Dentistry Today. Issue date: December
2008, “flexible removable partial denture, design and
clasp concept".
20. Micheal Sepe. 2008. Ides Articles .Design. http://
www. Ides.com/articles/design/2008/Sepe_02_asp.
21. Asgar K. Peyton FA. "Flow & fracture of dental alloys
determined by a micro bend tester". J Dent Res 1962;
41 (1): 142-53.
22. Osborne J, Lammie GA. "Some observations concern
Chrome-Cobalt denture bases". Br Dent J 1953; 94(3):
55-66.
23. Kotake M, Wakabayashi N, Ai M, Yoneyama T,
Hamanaka H. "Fatigue resistance of Titanium-Nickel
alloy cast clasps". Int J Prosthodontics 1997;10(6):
547-52.
24. Noort RV. Lamb DJ. "A scanning electron microscope
study of CO-Cr Partial dentures fractured in service "J
Dent 1984; 12(2); 122-6
25. Vallittu PK. "Transverse strength, ductility &
qualitative elemental analysis of Cobalt-Chromium
alloy after various durations of induction melting". J
Prosthodontic 1997; 6 (1): 55-60.
26. Craig RG, O'Brien WJ. Powers JM. "Dental Materials:
Properties & Manipulations", 6th ed. St Louis: Mosby,
1996; Ch 2:16-26; Ch 11 : 222-5.
REFERENCES
1. McGivney GP, Castleberry DJ. "McCracken's
Removable Partial Prosthodontics", 11th ed. St Louis:
Mosby, 2005; Ch. 1 : 3-4: Ch 6: 85-100: Ch 17:
397,401-402.
2. Glossary of Prosthodontic terms, 7th ed. JPD 2005; (1):
84.
3. R. John Davenport, Evelyn Strauss, and Kelly
LaMarco" Aging Knowledge. Enviroment.", 3 October
2001 Vol. 2001, Issue 1, p. vp1.
4. Negrutiu M, Sinescu c, Romanu M, Pop D, Lakatos s
(2005). Thermoplastic resins for flexible framework
removable partial dentures. Temisoara Med J; 55:29599.
5. Stafford GD, Huggett R, MacGregor AR, Graham J.
(1986): The use of nylon as denture base material. J
Dent.;14:18
6. Phoenix RD, Mansueto MA, Ackerman NA, Jones RE
(2004). Evaluation of mechanical and thermal
10
Vol. 24(2), 2012
A comparison of the retention
A comparison of the retention of complete denture bases
having different types of posterior palatal seal with
different palatal forms
Mayada Q. Abdul Khafoor, B.D.S, M.Sc. (1)
ABSTRACT
Background: The most common problem associated with the lack of retention of maxillary complete denture is faulty
posterior palatal seal pps. The methods for achieving a pps include arbitrarily scraping the cast, selective pressure
technique, and the physiologic impression technique.
Material and Method: In this study forces required to dislodge a maxillary complete denture bases were compared
for different types of posterior palatal seals (PPS) with different palatal forms by using a specially designed strain
gauge force tranducer and strain measuring device. Nine male and female subjects are selected with age range
55-70 years. These patients with different palatal forms according to House's classification of palatal forms: Class I flat,
Class II intermediate and Class III high. Using different impression technique the first ordinary impression with Zincoxide eugenol and scraping the cast for pps, the second physiological impression by using korecta wax No.4.
Result: The results show very highly significant difference, between the different designs of pps and physiological
impression for each group.
Conclusion: The physiological impression of pps give better retention because no over compression of tissues (within
the physiological limit) and concluded that the form of palate has direct influence on the retention of complete
dentures and will aid in the selection of type of posterior palatal seal needed.
Keywords: Maxillary complete denture, posterior palatal seal. (J Bagh Coll Dentistry 2012;24(2):11-17).
INTRODUCTION
-
Provide a thicker posterior border to
compensate for processing shrinkage of the
denture base in this area5, and
- Reduce discomfort when contact occurs
between the posterior border of the denture
and the dorsum of the tongue 4.
The methods for achieving a pps of a maxillary
complete denture include arbitrarily scraping the
cast prior to denture processing, the selective
pressure impression technique, and the
physiologic impression technique 6.
Winland and Young11 and Chen et al10 stated that
the most dental schools teach the method of
carving the pps arbitrarily in the maxillary cast.
This arbitrarily location and scraping of the
definitive cast was found to be the least accurate
technique the effectiveness of pps of maxillary
complete denture is confirmed only at the
insertion appointment.
The anterior vibrating line at the area of the
junction of the hard and soft palate can be located
by palpation of the hamular process and the fovea
palatine. The anterior vibrating line serves as the
anterior border of the pps area. The posterior
vibrating line lies in the junction of the
aponeurotic portion of the soft palate and
represents the posterior extension of the pps area,
they considered a two separate lines of flexion 12.
The location and incorporation of the pps on the
maxillary definitive cast are often done by the
dentist or dental laboratory technician. However
these procedures should be the responsibility of
the dentist, as the tissue displacement can only be
determined clinically 13. A faulty pps may cause
A well fitting and retentive complete maxillary
denture requires a well fitting surface a peripheral
border compatible with the muscles and tissues
which make up the muco-buccal and muco-labial
spaces so that a peripheral seal is created by the
soft tissues draping over them and finally, a
posterior palatal seal. Avants 1 has shown that "a
pps is necessary for optimum retention of
maxillary complete dentures" and that of the
designs he tested, none proved to be superior in
all of his five test subjects1.
The pps area has been defined as an area of soft
tissue along the junction of the hard and soft
palate on which pressure, within the physiologic
limits of the tissues, can be applied by a denture
to aid in its retention 2.
The pps of a maxillary complete denture can be
established during the making of the final
impression by scoring the final cast, or by
incorporating the seal in the finished denture base.
The technique can be classified generally as being
either functional or empirical 3. Regardless of the
technique used or the stage of denture fabrication
during which the pps is placed, the objective of its
utilization is the same. It provides aperipheral seal
by selectively displacing soft tissue to 4:
- Provide close tissue contact during speech and
swallowing, preventing food and debris from
impinging between the denture base and the
underlying tissue.
- Enhance retention and stability.
(1)Lecturer, Department of Prosthodontics, College of dentistry,
Baghdad University.
11
Vol. 24(2), 2012
Antolinocolon et al 8 concluded that the form of
the palate has direct influence on the retention of
complete denture will aid in the selection of the
type of posterior palatal seal needed.
poor retention and /or tissue irritation. Brian M et
al 6 describe a technique for the location of the
pps intraorally and accurate transfer to maxillary
complete denture cast by indelible pencile. Laney
and Gonzalez 14 discussed the need for knowledge
of the oral cavity's anatomy so that the static
surface of the denture base can be balanced
against one dynamic tissue surface. In the pps
area, the tissues are displaceable and the degree of
displacement can be found by palpation with a
"T" burnisher 15, by closing both nostrils of the
patient and having him blow gently 16 or by
visualizing the vibrating line as the patient says
"ah" 3. Also, by placing the tissues with various
impression materials, a functional or physiologic
pps can be impression made as early as the
maxillary final impression 18. Another method,
scraping the maxillary cast before final processing
of the denture, can be used to construct a pps 19.
Therefore, the pps takes on many various shapes,
size and locations. These various types of pps are
discussed by winland and Young11, and their
construction as taught in our dental schools is
investigated. They discussed that no mather what
type of pps is used, the important word is seal-to
seal out air and food and to seal in partial pressure
and they said that the determination of the
posterior limit and palatal seal of the maxillary
complete denture is not the technician's
obligation, but the responsibility of the dentist.
Abedalbaki et al 20 compare the retention of
complete denture bases with different types of pps
(bead, double bead, and bufferfly). They found no
design provide superior priority than the other
type of pps but a double beading and butterfly pps
can improve the retention of a maxillary complete
denture.
Determinants of posterior extension:
During the final impression appointment, the
final extension of posterior border of the
maxillary denture is determined. Factors to be
considered include:
- The drape of the soft palate in relation to the
hard palate. A more abrupt relation between
the hard and soft palates generally indicates
increased muscular functional activity of the
soft palate, thus reducing the potential
posterior extension of the palatal seal. 4
The shape of palatal vault is related to the activity
of the soft palate. The flat vault has the least
movable soft palate and the widest area of
displacable tissue. In contrast, the high vault or
"V" shaped palate often has a soft palate virtually
at right angles to the hard palate and is extremely
mobile. Thus the area of tissue displaceability is
very narrow. The intermediate palatal vault lies
between these two extremes 7,21.
MATERIALS AND METHOD
A. The testing apparatus
For the purpose of this study, retention has
been expressed in term of force required to
vertically dislodge a maxillary complete
denture using a specially designed strain gauge
force tranducer. The data measured by gram 23.
The apparatus consist of many parts as shown
in figure 1.
B. Selection of patients
Nine edentulous patients were selected from
prosthodontic clinic, college of dentistry,
Baghdad University, 6 males and 3 females,
the age range between 55-70 years, the criteria
used for selection were relatively smooth, firm
alveolar ridge covered with healthy mucosa
without any posterior under-cuts. The patients
with different palatal form according to
House's classification of palatal forms: Class I
flat palatal vault in the hard palate and Class
III a high vault and Class II intermediate
between them 7,30.
C. Impression techniques:
A preliminary impression with impression
compound (Quayle Dental, England) was
taken and 2 custom trays were fabricated on
the study model. Then two impression
techniques used:
I. First impression technique:
1. Before the border molding procedure,
trim and adjust the posterior border of
the custom tray 1 to 2 mm distal to the
vibrating line.
2. Complete the border molding and make
a final impression by using zinc oxideeugenol (ZoE) paste.
3. Remove the impression from the mouth.
4. Mark the vibrating line in the mouth
with indelible pencile by using "ah"
sound with nose blowing and using the
fovea palatinae in locating the vibrating
line 24.
5. Reinsert the maxillary impression in the
mouth and transfere the location of
vibrating line to the ZoE impression.
6. Poured with stone (Zeta, selensor,
Industria Zingardi S,r,i, Italy). The
water to powder ratio recommended by
the manufacturer was used.
7. The master cast was then duplicated
once by using heavy body silicon, the
12
Vol. 24(2), 2012
to exert their displacing effect on wax,
there by achieving functional depth of
seal. Figure (2)
8. Impression is carefully beaded and
boxed and the impression then poured
with stone (Zeta, Selensor, Industria
Zingardi s.r.i Italy). The water powder
ratio recommended by the manufacturer
was used. This cast was marked 1.
D. Scraping the casts for incorporation of pps:
The casts marked 2 and 3 were scraped to
carve certain designs into their posterior
palatal areas. No. 4 round bur with a lacron
carver were used. The patients classified into
groups according to House's cassification of
palatal form.
Group A (Class I flat palatal form)
A1= physiological impression technique of
pps
A2= scraping the cast 2 according to Housemodified butterfly 3-4mm wide and 1mm
deep was carved in the center of the palatal
seal area passing through the hamular
notches and flushing out on approaching the
buccal sulcus 26.
A3= Scraping the cast 3 –a single bead
design as described by boucher 25. A V
shaped groove 1mm deep and wide at the
base was carved; it passed to rough the
hamular notches and flashed out approaching
the buccal sulcus.
Group B (Class II intermediate palatal form)
B1= physiological impression technique of
pps
B2= Scraping the cast 2 according to Housemodified butterfly 2-3mm wide and 1mm
deep was carved in the center of the palatal
seal area passing through the hamular
notches and flushing out on approaching the
buccal sulcus 26.
B3= Scraping the cast 3-asingle bead design
as described by Boucher 25, like A3 group.
Group C (Class III high palatal form)
C1= physiological impression technique of
pps
C2= Scraping the cast 2 according to Housesingle bead design 26 1mm width and depth
made on the posterior vibrating line.
C3= scraping the cast 3-abutterfly shaped
configuration was carved as suggested by
Hardy and Kapur 3. An angled groove
1.0mm deep and 1.5mm wide at the base was
carved in the center of the palatal seal area
passing through the hamular notches and
flushing out on approaching the buccal
sulcus Figure (3).
master cast marked 2 while the
duplicated cast was marked 3.
II. The
second
impression
technique
(Physiological posterior palatal seal).
1. The same steps 1, 2 and 3 used in the
previous technique.
2. The anterior vibrating line can be
visualized by instructing the patient to
say "Ah" with short vigorous bursts
while the posterior vibrating line can be
visualized by instructing the patient to
say "Ah" in short bursts in a normal
unexaggerated fashion, then mark the
anterior and posterior vibrating lines in
the mouth with indelible pencile and
transfer the location to the ZoE
impression.
3. Kerr Korecta wax No. 4 was used to
record the pps area, it’s a fluid, mouth
temperature wax, is preferred for this
procedure. It will flow sufficiently at
mouth temperature to avoid over
displacement of tissues. because the
wax continues to exhibit it property of
flow in the mouth, it permits the tissues
in the area of the pps to rebound,
establishing a degree of displacement
that is physiologically acceptable. This
wax is painting on pps area of
impression.
4. Impression is reseated in mouth and
held in place for about 3 minutes.
Patient is guided and instructed to tip
head forward to approximately 30o from
vertical position and forcibly place
tongue against tray handle or clinician's
finger which is supporting tray, this
maneuver allow pps area to be recorded
in functional position 4,22.
5. Excess wax will be displaced and will
flow posteriorly.
6. Impression is removed and examined
wax that has flowed posterior to seal is
removed with Bard-parker blades,
intimate contact between wax and
tissues is indicated by glossy
appearance of wax in contrast to dull
appearance where no contact exists.
Wax is painted on where indicated and
the impression is reseated intraorally
until wax exhibits contact along entire
posterior palatal area.
7. After trimming excess wax, impression
is reseated for five to eight minutes.
During this time, patient intermittently
repeats head and tongue positions. This
last seating allows tissues in area of pps
13
Vol. 24(2), 2012
The mean values of the statistical analysis for the
data of group C (deep palatal form) between the
three groups C1, C2 and C3 as shown in Table
(5). The results of ANOVA table with LSD as
shown in Table (6). The results explained that
there was a very highly significant difference
between groups and between groups (C1 and C3)
and between (C2 and C3) groups. While a non
significant difference between (C1 and C2)
groups.
E. Construction of the test denture bases:
Identical denture bases for the pps were made
on cast 1, 2 and 3 for each group and were
designated 1, 2 and 3 respectively. Base plate
was formed for each of the casts using two
mm thick layers of base plate wax, the bases
were processed using heat curing acrylic resin
(Quayle Dental, England).
F. Clinical testing
Astringe of about 1 inch length was secured
on the polished palatal surface of each of the
maxillary denture bases in region relating to
the second premolar and first molar teeth 14,
20
, with auto polymerizing acrylic assembly
(Figure 4). The dislodging force that is
directed to the maxillary denture bases was
applied at the middle of the denture base
where the middle location is considered the
most reliable region for testing the retention
of complete maxillary denture 15.
All tests for a subject were completed in one
appointment; all the denture bases for that subject
were stored in water for the same length of time
before being tested for retention. Thus, the time of
day and water sorption was not variables.
The patient head was held firmly on the head rest
with occlusal plane parallel to the floor. Figure (5)
all measurements of retention involving in a given
subject were conducted at one sitting, each test
denture base was subjected to three retention tests.
The force values at which the denture base was
dislodged completely from the palate at a steadily
increasing force was displayed on strain
measuring device represented by gram, the force
values in grams could be calculated.
DISCUSSION
An adequate seal of the posterior border of a
maxillary complete denture is essential for
retention. Establishing the pps at final impression
stage confirm the effectiveness of the pps and
allows the dentist to control its location and the
amount of tissue displacement 10,27. This is agree
with the result of this study which revealed that
the physiological impression technique of pps
area give better retention for complete denture
base than the other technique of pps. Vintion 28
stated, "where the tissues move in normal function
is the area where maximum peripheral seal can be
achieved with the least amount of tissue
displacement. This appears to be best
physiologically. It is maximum result with
minimum activity 11.
The route of the vibrating line from one side of
the palate to the other is not of a definite pattern
but varies with the shape of the palate. This
variation is such a constant observation that palate
or throat forms have been classified as Class I,
Class II and Class III. Class I indicates a low, flat
vault in the hard palate which continues into a soft
palate that has a minimal amount of drop and
movement. This situation permits a more distal
extension of the maxillary denture and provides
broader pps area 17. This agree with the result of
group A, it was found that the physiological
impression technique and modified butterfly 34mm width for pps area give better retention than
the single bead design of pps. Nikoukar 17 and
Swenson and Terkla 9 were found that the flat
palatal shape has vibrating line located farther
posteriorly.
While in Class III indicates a high vault in the
hard palate and an acute drop and maximal
movement in the soft palate. The region where
this acute drop occurs becomes extremely critical
because it places greater limitations on the distal
extension of the maxillary denture and will
accommodate only a narrow pps 17. This agree
with the result of group (C) which revealed that
the physiological impression technique of pps and
single bead design of House give better retention
for complete denture base than the butterfly shape
RESULTS
The mean values of the statistical analysis for the
data of group A (flat palatal form) between the
three groups of A1, A2 and A3 were shown in
Table 1. Where as the results of ANOVA table
with LSD as shown in table 2. The results
explained that there was a very highly significant
differences between the groups and between (A1
and A2) and between (A1 and A3) and between
(A2 and A3) groups. While the mean values of the
statistical analysis for the data of group B
(intermediate palatal form) between the three
group B1, B2, and B3 as shown in Table (3).
Where as the result of ANOVA table with LSD as
shown in Table (4). The result explained that
there was a very highly significant difference
between groups and between groups (B1 and B3)
and between (B2 and B3), while there was a non
significant differences between groups (B1 and
B2).
14
Vol. 24(2), 2012
of pps (Hardy and Kapur) 3. Nikoukari 17,
Swenson and Terkla 9 found that the higher the
vault the more abrupt and forward is the vibrating
line. While the Class II designates those palatal
forms which are intermediate between Class I and
Class III 17. This agree with the result of group B
which revealed that the physiological impression
of pps and modified butterfly 2-3mm width
according to House give better retention for
complete denture base than the single bead design
of pps (Boucher).
The mucosal tissues of the pps area vary in
displaceability from patient to patient, the task of
determining the shape, size and depth of the seal
must be accepted by the clinician and should not
be assigned to the Laboratory technician. It is
quite improssible to establish the posterior limit,
the width and depth of the seal in an edentulous
cast alone, and it is the clinician's responsibility to
make the decision based on proper procedures in
the mouth.
10. Chen MS, et al. Methods taught in dental schools for
determining the posterior palatal seal region. J
Prosthet Dent1985; 53: 380-3.
11. Winland RD, Young JM. Maxillary complete denture
posterior palatal seal: variation in size, shape and
location. J Prosthet Dent 1973; 29(3): 256-61.
12. Vernie AF, Chitre V, Aras M. A study to determine
whether the anterior and posterior vibrating lines can
be distinguished as two separate lines of flexion by
unbiased observer: Apilot study Indian J of Dental
Research 2008; 19(4): 335-9 [IVSL].
13. Winkler S. Essentials of complete denture
prosthontics. 2nd ed. St. Louis: Ishiyaku Euro America;
1994.
14. Laney WR, Gonzalez JB. The maxillary Denture: Its
palatal Relief and posterior palatal seal. J Am Dent
Assoc 1967; 75: 1182-7.
15. Bylicky HS. Variable Approaches in obtaining a
posterior palatal seal: Description of Technique. NYJ
Det 1966; 36: 280-2.
16. HeartWell GM, Rhn AO. Syllabus of complete
dentures. 1st ed. Philadelphia: Lea and Febiger
publishers; 1968.
17. Nikoukari H. A study of posterior palatal seal with
varying palatal forms. J Prosthet Dent 1975; 34: 60513.
18. House MM. Full Denture Techniques study club No.1,
1950.
19. Stephens AP. Upper full denture retention. J Irish Dent
Assoc 1968; 14: 131-2.
20. Mohammed AA, et al. Company required dislodging
forces between different types of posterior palatal seal.
Mustansiria Dent J 2006; 3(1): 97-101.
21. Watt DM, Mac Greagor AR. Designing complete
dentures. Philadelphia: W.B. Saunders company;
1976. 83-6.
22. Silverman SI. Dimension sand displacement patterns
of posterior palatal seal. J Prosth Dent 1971; 25: 470.
23. Ilham HAA. The effect of three different denture
adhesives on the retention of mandibular complete
denture (comparative study). A master thesis, College
of Dentistry, University of Baghdad, 2008.
24. Behnoush R, Vicki CP. Current concepts for
determining the posterior palatal seal in complete
denture. J Proth Dent 2003; 12(4): 265-70.
25. Boucher CO. Swensons complete dentures. St. Louis:
The C.V. Mosby Co.; 1964. Pp. 115, 453-60.
26. Sudhakara V M, Karthik KS. A review on posterior
palatal seal. JIADS 2010; 1(1):16-21.
27. Ansari HI. Estabishing the posterior palatal seal during
the final impression stage. J Prosthe Dent 1997; 78(3):
324-6.
28. Vinton PW. Posterior palatal seal. personal
communication, 1971.
REFERENCES
1. Avants WE. A comparsion of the retention of
complete denture bases having different types of
posterior palatal seal. J Prosthet Dent 1973; 29(50):
484-93.
2. Roland LE, Forrest RS. The posterior palatal seal. A
review. Australin Dent J 1980; 25 (4): 197-200.
3. Hardy IR, Kapur KK. Posterior border seal its
rationale and importance. J Prosthet Dent 1958; 8(3):
386-7.
4. Gerald SW. Establishing the posterior palatal seal
during the final impression procedure: a functional
approach. J Am Dent Assoc 1977; 94: 505-10.
5. Anthony DH, Peyton FA. Dimensional accuracy of
various denture base materials. J Prosthet Dent 1962;
12: 67-81.
6. Brian W, Robert F. Accurate location of posterior
palatal seal area on the maxillary complete denture
cast. J Prosthet Dent 2006; 96 (6): 454-5.
7. Sudhakara VM, Sudhakara UM, Karthik KS, Udita
SM. A review on Diagnosis and treatment planning for
completely edentulous patients. JIADS 2010; 1(1): 1621.
8. Colon AK, Kotwal K, Mangelsodroff AD. Analysis of
the posterior palatal seal and the palatal form as
related to the retention of complete dentures. J
Prosthet Dent 1980; 47(1): 23-7.
9. Swenson MG, Terkla LG. Complete denture. 6th ed. St
Louis: The C.V. Mosby company; 1970. pp. 65-70,
372-6.
Table 1: Means and standard deviation of Group A
Group A
A1
A2
A3
Total
Mean
309.3333
186.0000
119.6667
205.0000
15
N
3
3
3
9
Std. Deviation
17.92577
12.16553
13.61372
84.33119
Vol. 24(2), 2012
Table 2: ANOVA and LSD of group A
Group A
Between Groups
Within groups
Total
Group A
A1 A2
A3
A2 A3
Sum of squares
55584.667
1309.333
56894.000
df
2
6
8
Mean Difference (I-J)
123.33333
189.66667
66.33333
Mean square
27792.333
218.222
Std. Error
12.06157
12.06157
12.06157
F
127.358
Sig.
0.000
Sig.
0.000
0.000
0.002
The mean differences is significant at the 0.05 level
Table 3: Means and SD of group B (deep palatal vault)
Group B
B1
B2
B3
Total
Mean
490.0000
480.0000
257.0000
409.0000
N
3
3
3
9
Std. Deviation
10.00000
20.00000
23.30236
115.21936
Table 4: ANOVA and LSD of group B
Group B
Between Groups
Within groups
Total
Group B
B1 B2
B3
B2 B3
Sum of squares
104118.000
2086.000
106204.000
df
2
6
8
10.00000
233.00000
223.00000
Mean square
52059.000
347.667
F
149.738
Std. Error
15.22425
15.22425
15.22425
Sig.
0.000
Sig.
0.536
0.000
0.000
Table 5: Means and standard deviation of Group C
Group C
C1
C2
C3
Total
Mean
399.3333
392.6667
244.3333
345.4444
N
3
3
3
9
Std. Deviation
6.02771
11.23981
41.78915
78.97011
Table 6: ANOVA and LSD of Group C
Group C
Between Groups
Within groups
Total
Group C
C1 C2
C3
C2 C3
Sum of squares
46072.222
3818.000
49890.222
df
2
6
8
6.66667
155.00000
148.33333
Mean square
23036.111
636.333
Std. Error
20.59666
20.59666
20.59666
F
36.201
Sig.
0.757
0.000
0.000
16
Sig.
0.000
Vol. 24(2), 2012
Figure 1: Strain gauge force tranducer
Figure 2: Physiological impression of pps
Figure 3: All casts of each groups
Figure 4: Astring of 1 inch in length on the
polished surface
Figure 5: The patient during testing procedure
17
Vol. 24(2), 2012
An evaluation of the
An evaluation of the use different techniques of the
thermoplasticized obturators on the coronal seal
Mervat M. Al-Bakri, B.D.S., M.Sc. (1)
Hussain F. Al-Huwaizi, B.D.S., M.Sc., Ph.D. (2)
ABSTRACT
Background: The aim of the present study was to evaluate coronal leakage of root canals obturated by various
techniques.
Methodology: Straight single rooted teeth with mature apices (6 groups of 10 teeth each). Root canals were
prepared according to the crown down technique using hand ProTaper system. Endofill root canal sealer and 2.5%
sodium hypochlorite was used. Root canals were obturated using cold lateral condensation Thermafil and Soft Core
obturation after root canal filling the six groups was divided into two individual groups of 30 teeth. The first group of 30
teeth was kept for 1 week the second 3 week at 37 oC. Teeth were immersed in india ink. Each was split and
sectioned longitudinally and the maximum extent of leakage was measured using a stereomicroscope
Results: Leakage occurred whatever filling technique was used the number of teeth with gross leakage decreased
with time up to 3 weeks. There were significant differences in coronal leakage between the various obturation
techniques after 1 week, and after 3 weeks. No statistically significant differences were found between soft-Core and
cold lateral condensation after 1 week and statistically significant differences were found after 3 weeks. There were
statistically significant differences between Thermafil and lateral condensation after 1 week and no statistically
significant differences after 3 weeks.
Conclusion: Under the conditions of the present study none of the gutta-percha obturation techniques prevented
coronal leakage. Coronal leakage increased during the first week for CLC, Thermafil and Soft-Core obturators, and
decreased after 3 weeks. Coronal leakage in the Soft-Core obturators was higher than Thermafil and CLC after one
week. Thermafil coronal leakage was lower than others after one week. Coronal leakage in the Soft-Core obturators
higher than Thermafil and CLC after three weeks coronal leakage was equal in Thermafil and CLC after three weeks.
Keywords: Endofill root canal sealer HPT, leakage, obturtion, CLC, Thermafil, Soft-Core. (J Bagh Coll Dentistry
2012;24(2):18-20).
INTRODUCTION
The provision of a well-compacted and highly
tightly adapted root filling is one of the goals of
root canal treatment. However, contemporary
obturation techniques and filling materials do not
seal completely the root canal system up to the
level of the cemento-enamel junction. Moreover,
it is accepted that both apical and coronal leakage
can occur following apparently successful root
canal treatment (1, 2). Several factors appear to
influence the extent of both apical and coronal
leakage. Furthermore, various root canal filling
techniques based on heated or preheated guttapercha have been introduced in order to enhance
complete filling of the root canal. These include
warm vertical condensation (3), warm lateral
condensation (4), thermatic compaction (5), hybrid
condensation, i.e. a combination of cold lateral
condensation and thermomechanical compaction
(6)
, thermoplasticized gutta-percha as a coating on
a flexible carrier (7), and injection moulded
thermoplasticized guttapercha (8).
The aim of the present study was to evaluate
coronal leakage of root canals obturated by
various techniques.
MATERIAL AND METHOD
Sixty extracted human straight single-rooted teeth
with mature apices were used in this study. Both
carious (limited occlusal and/or interproximal
lesions without pulp exposure) and non-carious
teeth were included. All teeth were stored in 10%
formalin until the sample was completed.
Sample preparation
The crowns were removed 2mm above the
cement-enamel junction with a high-speed fissure
bur and water spray.
After gross removal of pulp tissue, a size 10
Flexofile was introduced into the canal until it
could be seen in the major apical foramen. The
working length was determined by subtracting 1
mm from this length. The root canals were
prepared by means of a crown-down technique,
using the Protaper Hand system until F3.
The canals were copiously irrigated with 2.5%
sodium hypochlorite solution with a 27 gauge
endodontic needle.
The canals were dried with paper points and the
patency of the apical foramen was confirmed with
a size 10 Flexofile. The roots were randomly
divided into 6 experimental groups of 10 roots
each.
(1) Assistant lecturer. Department of Conservative Dentistry.
College of Dentistry, University of Baghdad.
(2) Professor. Department of Conservative Dentistry. College of
Dentistry, University of Baghdad
18
Vol. 24(2), 2012
other 3 groups for 3 weeks. After which they were
thoroughly washed with running water. The nail
varnish was removed, the teeth were then air
dried. Longitudinal shallow grooves were made
on the buccal and lingual surface with a rotating
diamond disc of small diameter under continous
water cooling, and the teeth carefulyl fractured
and sectioned with a sharp chisel.
The degree of microleckage was determined by
measuring the linear extent of India ink
penetration from the surface of the coronal g.p at
the level of the amelocemental junction to the
position of the maximum dye penetration apically
(coronal leakage testing).
To eliminate bias, coronal leakage were measured
independently by two evaluators who were
unaware of the obturation techniques used. All
measurements were obtained by means of a stereo
microcope with calibrated scale ocular.
Following drying with paper points, the canals
were obturated by one of the following
techniques.
Group 1: Cold lateral condensation of guttapercha
A standard size g.p cone that matched the master
apical file was fitted to the working length with
atugback Endofill root canal sealer was mixed
according to the manufacturer's instructions and
placed in the canal by coating the cone with sealer
and gently seating it at the working length. Lateral
condensation was then carried out using size 20
and 25 accessory g.p cones with endotontic finger
spreader placed within 1 mm of the working
length. The g.p cones coated with sealer were
laterally condensed until they could not be
introduced more than 3mm into the root canal.
Following obturation, the g.p was removed from
the coronal cavity up to the level of CEJ with a
warm instrument and vertically condensed with
Machtou pluggers.
Group 2: Thermafil obturation
The correct size of the plastic core thermafil
obturator was selected using the verification kit.
The obturators were then placed in the Thermaprep oven according to the manufacturer's
instructions. The sealer was sparingly introduced
into the canal, after which the plasticized
thermafil device was inserted to the apical stop.
The shank of each carier was cut at the canal
orifice using an inverted cone bur in a high speed
hand piece and the g.p was compacted vertically
with a plugger.
Group 3 Soft core obturation
The correct size of the plastic core Soft-Core
obturator was selected using the size verifier. The
obturators were then placed in the Soft Core Over
(Soft Core System). When the oven indicated that
the obturator was ready, it was removed from one
of the slots in the top of the oven endofill sealer
was sparingly introduced into the canal, after
which the plasticized Soft Coe device was
inserted into the apical stop. The handle and
insertion pin were removal by a twisting motion.
Excess plastic core material was removed with a
small inverted cone bur and any extra g.p
removed. The g.p was then compacted vertically
with a Machtou plugger.
Staining, longitudinal splitting and dye
measurement
After obturation, the teeth were stored in 100%
humidity for 48 hr. to ensure the sealer was set.
The roots were covered with a nail varnish, the
first coat was allowed to dry and a second coat
was applied. All teeth were immersed in a bath of
India ink and stored at 37oC for 1 week and the
RESULTS
The teeth showed dye penetration along the entire
length of each root canal. No significant
differences amongst the observers were scored, so
that the calculation of the average leakage values
of the two observers for each root was justified.
Since the data indicated a non-normal
distribution, leakage was assigned using the
following categories:
Coronal leakage was measured to the deepest
point.
Statistical analysis was carried out using the
ANOVA test between six groups to determine
whether there were significant differences
between the groups. Pairs of groups were
compared using the LSD or t-test.
Linear coronal leakage of the experimental
roots
The result for coronal leakage is provided in table
1. There were significant differences in coronal
leakage between the various obturation techniques
after 1 week, and after 3 weeks. According to the
t-test statistically significant differences were
found between Soft-Core obturators and
Thermafil after 1 week and after 3 weeks.
No statistically significant differences were found
between soft-Core and CLC after 1 week and
statistically significant differences were found
after 3 weeks. There were statistically significant
differences between Thermafil and lateral
condensation after 1 week and no statistically
significant differences after 3 weeks.
19
Vol. 24(2), 2012
differences in methods of measurement of coronal
leakage also the result of this study was in
agreement with Saunders and Saunders (12) in
which after 7 days, there was significantly less
leakage in these teeth obturated with Thermafil.
Table 1. Descriptive statistics of the groups
REFERENCES
1. Hovland EJ, Dumsha TC. Leakage evaluation in vitro
of the root canal sealer cement sealapex. International
Endodontic Journal 1985; 18: 179-82.
2. Saunders WP, Saunders EM. Coronal leakage as a
cause of failure in root canal therapy: a review.
Endodontics and Dental Traumatology 1994; 10: 15-8.
3. Schilder H. Filling root canals in three dimensions.
Dental Clinics of North America 1967; 11: 73-44.
4. Endotec Thermal Endodontic Condenser System. The
warm lateral condensation Technique Clinical Manual.
Dentsply Int. Inc. Milford DE. USA: The LD Caulk
Division. 1986.
5. Mc Spadden JT. Self study Course of the Thermatic
Condensation of Gu Ha Bercha. Dentsply Int. Inc.
Milford DE. USA: LD Caulk Division. 1980.
6. Tagger M, Tamse D, Katz A, Korzen BH. Evaluation
of the apical seal produced by a hybrial root canal
filling method, combining lateral condensation and
thermatic compaction. Journal of Endodontics 1984;
10: 299-303.
7. Johnson WB. A new gutta-percha technique. Journal
of Endodontics 1978; 4: 184-8.
8. Yec FS, Marlin J, Krakow AA, Gron P. Threedimensional obturation of the root canal injection
molded, thermoplasticized dental gutta-percha. Journal
of Endodontics 1977; 3: 168-74.
9. Wu MK, Wesselink PR. Endodontic leakage studies
reconsidered Part I: Methodology, application and
relevance, International Endodontic Journal 1993; 26:
37-43.
10. Dalat DM, Spangberg LSW. Comparison of apical
leakage in root canals obturated with various guttapercha techniques using a dye vacuum tracing method.
Journal of Endodontics 1994; 20: 315-9.
11. Kontakiotis E, Chaniotis A, Georgopoulou M. Fluid
filtration evaluation of 3 obturation techniques 2007.
12. Saunders WP, Saunders E. Influence of smear layer on
the coronal leakage of thermafil; laterally condensed
guttapercha root fillings with a glass ion sealer, 2012.
Figure 1: The coronal leakage of the
different groups in different times
DISCUSSION
In order to evaluate the sealing ability of root
fillings, several in vitro methods have been
designed. It is important to appreciate that not
only is the apical seal of the root canal of
importance, but the coronal seal is of equal
importance for the success of treatment (9). The
most common method used to assess leakage
remains the measurement of dye penetration (9).
The result of dye penetration studies, however, is
confusing and often results in variable
conclusions (10). This lack of agreement has been
discussed by Wu and Wesselink (9), who
questioned, the validity of leakage studies and
recommended that more research should be
devoted to leakage study methodology.
Longitudinal sectioning of roots and the linear
measurement of dye penetration were used in the
present study for the measurement of leakage.
Splitting the root longitudinally combined with
dye penetration enable the demonstration of the
pattern of dye penetration.
In the present study obturation with soft core
obturators resulted in greater leakage scores.
This may indicate that Soft Core obturators are in
effective these might be related to Soft Core has
less taper core so more gutta percha-core ratio
than Thermafil therefore it exerts more
contraction. In addition, it was also seen that
coronal leakage decreased with time up to 3
weeks in all three obturation techniques.
In this study we found that Thermafil coronal
leakage was lower than other obturation
techniques and this result was disagree with
Kontakiotis et al (11). These might be related to the
20
Vol. 24(2), 2012
An evaluation of apical
An evaluation of apical microleakage in roots filled with
thermoplastic synthetic polymer based root canal filling
material (RealSeal 1 bonded obturation)
Nadine J. Adbul-rada, B.D.S. (1)
Adel F. Ibraheem, B.D.S., M.Sc. (2)
ABSTRACT
Background: This study aimed to evaluate and compare the apical microleakage of roots canal filled with cold
lateral condensation of gutta-percha, cold lateral condensation of Resilon, Thermafil and RealSeal1 bonded
obturation.
Materials and methods: Sixty freshly extracted maxillary first molars with straight palatal roots .Using diamond disc bur
with straight hand piece and water coolant the palatal roots of teeth were sectioned perpendicular to the long axis
at the furcation area. All roots were prepared with crown-down technique using hand ProTaper system (Sx-F4).The
prepared roots randomly divided into 4 groups of fifteen roots each; the groups obturated with different obturation
technique. In Group 1 roots obturated with( lateral condensation of gutta-percha), Group 2 was obturated
with(lateral condensation of Resilon),group3 was obturated with (Thermafil) while in group4 obturated with( RealSeal
1 bonded obturation).All the samples sealed coronally and stored in normal saline at 37°C for one week ,then all the
roots submerged Indian ink for one week. The roots were cleared and the degree of linear dye penetration was
measured in millimeter by stereomicroscope under 40X magnification with calibrated scale ocular grid.
Results: The results showed that the RealSeal1 bonded obturation leaked apically significantly higher than other test
groups, while the group of lateral condensation of gutta-percha exhibited the least value of apical microleakage.
Conclusion: The complete hermetic apical seal cannot be created neither with gutta-percha nor with Real Seal
1bonded obturation.
Keywords: Apical microleakage, gutta-percha, RealSeal 1bonded obturation. (J Bagh Coll Dentistry 2012;24(2):2126).
INTRODUCTION
Complete obturation of the root canal with an
inert filling material and creation of a fluid-tight
seal are among the major goals of successful
endodontic treatment (1).The main three functions
of obturation are to entomb any bacteria
remaining within the root canal system; to stop
the influx of periapical tissue derived fluid from
entering the root canal to feed the surviving
bacteria; and to prevent coronal leakage of
bacteria. Although gutta-percha has many
desirable properties, including chemical stability,
biocompatibility, non porosity, radiopacity and
the ability to be manipulated and removed, it does
not always meet the three functions of
obturation(2).
Gutta-percha does not bond to the internal
tooth structure, resulting in the absence of a
complete seal (3).Many attempts have been made
to resolve the problem through the variation in
obturation technique including vertical and lateral
condensation and the use of reverse-fill or touch
and heat system.
These methods have reduced microleakage to
ascertain degree but still have failed to eliminate
( ).
the problems 4
In 2004, a new core material Resilon
(Resilon Research LLC, Madison, CT, USA)
in conjunction with an adhesive system
(Epiphany, Pentron Clinical Technologies,
Wallingford, CT, USA) was introduced to
the market. Thisthermoplastic-filled polymer
core polycaprolactone-based has potential to
challenge gutta-percha the ‘gold standard as
a root filling core material (5). Resilon is a
thermoplastic synthetic polymerbased root
canal filling material. Based on polymer of
polyester, Resilon contains bioactive glass
and radiopaque fillers. Epiphany is a dual
curable resin composite used as a sealer
combined with Resilon points. According to
manufacturer, Epiphany sealer bonds both to
dentin and also to root canal filling material.
This may be an important fact to eliminate
microleakage since it is well-known that
microleakage occurs not only through sealerdentin but also through sealer and root canal
filling material Interfaces (6,7).
Samples Selection
Sixty freshly extracted maxillary first molars
teeth. The criteria for teeth selection Straight root
canal mature centrally located apical foramen,
patent apical foramen, roots devoid of any
(1)M.Sc. student, dep. of conservative dentistry, college of
dentistry, university of Baghdad.
(2)Professor dep. of conservative dentistry, college of dentistry,
university of Baghdad.
21
Vol. 24(2), 2012
resorption, cracks or fracture and the palatal roots
will be 10mm in length from the apex up to
furcation area(8).
Samples preparation
After extraction, all teeth will be stored in distilled
water at room temperature. Any soft tissue
remnants on the root surface were removed with
sharp periodontal curette. The crown of the tooth
was sectioned perpendicular to the long axis of
the root at the furcation area with a disc diamond
and the root length adjusted to 10mm from flat
reference point to the root apex. The patency of
the canal was checked by passing# 10 K file 1mm
through the apical foramen and the working
length equal to 9 mm. Silicon rubber base (heavy
body) was mixed (Base and catalyst) according to
the manufacturer instructions loaded with hand
and inserted it in a perforated plastic container
(dimension 13mm, height 52mm) using spatula to
adapt heavy body to the wall of the plastic
container then the sectioned root centered inside
the rubber base. Heavy body left to set forming
small blocks to facilitate handling of roots during
instrumentation and obturation. The canals were
prepared with crown-down technique using (hand
use) Protaper system (Sx to F4). According to the
manual instruction, the motion of instrumentation
was clockwise reaming action with sufficient
apical pressure till the file engaged the dentin
about four rotations at each time till the file
became passive, then the file was pulled and its
flutes cleaned from the dentin debris frequently
and inspected for any sign of distortion.
Obturation of the roots:
Group 1: In this group roots were obturated with
cold gutta-percha points (lateral condensation
technique) using AH-26 sealer. AH-26 was mixed
a, on a dry, clean glass slab with spatula. The
mixture had a homogenous creamy consistency
that string out at least one inch when the spatula
was raised slowly from the glass slab. The canal
was dried using paper point and sealer was
introduced into the canal to full working length
using file F4 by pumping action of the file with
simultaneous rotary movement in a counterclock
direction to coat the canals with thin film of
sealer. The tip of master gutta-percha cone
corresponding to the last file size #40 was dipped
into the sealer and placed in the canal. The
previously checked finger spreader size 35 is
inserted between the master cone and the canal
wall within 1-2 mm from the working length.
Spreader taper is the mechanical force that
laterally compresses and spreads gutta-percha
creating a space for additional accessory cones.
The tip of accessory point size #20 was dipped in
the sealer and inserted into the canal by space left
by the spreader; this was followed by more
spreading and more accessory cone until the
spreader could not enter more than 2-3 mm into
the canal orifice. When obturation of teeth was
accomplished, the excess gutta-percha removed
with heated endodontic plugger to a level (1mm)
higher than the coronal end of roots and vertically
condensed with root canal plugger, so the guttapercha obturate the entire canal up to the coronal
terminus. The roots were coronally sealed by
temporary filling.
Group 2: In this group roots were obturated with
Resilon and Real Seal SE sealer by lateral
condensation technique. The dual syringe (with
mixing tip) was used to express the sealer onto the
mixing pad then the sealer was carried to the canal
on the paper point according to manufacturer
instruction .The master cone size 40 was coated
with the sealer and placed into its correct working
length within the canal. A finger spreader size 35
was inserted between the master cone and the
canal wall within 1-2 mm from the working
length. Spreader taper is the mechanical force that
laterally compresses and spreads Resilon creating
a space for additional accessory cones. The tip of
accessory point size #20 was dipped in the sealer
and inserted into the canal by space left by the
spreader; this was followed by more spreading
and more accessory cone until the spreader could
not enter more than 2-3 mm into the canal orifice.
The excess Resilon was seared off with a hot
endodontic plugger and vertically was condensed
with endodontic plugger and then the coronal
third of each root was cured using the light curing
device for 40 seconds according to manufacturer
instruction. The coronal 1 mm of each root sealed
with glass ionomer cement as a temporary
restoration according to manufacturer of Real Seal
system.
Group3: In this group roots were obturated by
Thermafil cones and AH-26. The stoppers were
placed on the cone according to the working
length and then the matching size verifier was
inserted into the canal to the working length. The
sealer was introduced into the canal in the same
manner as Group 1. Thermafil cones (size 40)
were placed in one of the heating chamber of
ThermaPrep plus oven (Size 30-60 button is
chosen). After beep sound, the oven was switched
off then the cone raised without rotation and
inserted inside the canal firmly and slowly to
working length without any twisting or rotation.
The handle was removed after the gutta-percha
cooled by inverted cone bur in high speed hand
piece. The roots were coronally sealed by
temporary filling (Citodur).
22
Vol. 24(2), 2012
under 40X magnification with calibrated scale
ocular to establish the degree of apical dye
penetration in millimeters.
Group4: In this group roots were obturated with
Real Seal 1 obturator and Real Seal SE sealer
according to manufacturer instruction. The
stopper was placed on the matching size verifier
and then it inserted into the canal to the working
length. The verifier should fit passively in the
canal. Then RealSeal 1 (size 40) were placed in
one of the heating chamber of RealSeal 1 oven
(Size 40-60 button is chosen). The heating time
needed to heat RealSeal1was regulated
automatically about1:30 minutes, during this time
SE sealer was dispensed and introduced to the
canal in the same manner as Group 2. After the
first” beep” signal the obturator is ready for
removal from the unit and inserted in the canal
within 6 seconds without any twisting or forcing.
The handle and the shaft were removed with
inverted cone in a high speed hand piece then was
light cured the coronal surface of the RealSeal1
obturator for 40seconds. The coronal 1 mm of
each root sealed with glass ionomer according to
the manufacturer instruction.
Sample storage: After obturation the samples
were stored in incubator at 37°C for a week to
ensure complete setting of the sealer (9).
Leakage study: Each group had one root as a
negative control and one root as a positive control.
The negative control roots were coated
completely with one layer of nail varnish and two
layers of sticky wax, while positive control roots
were left uncoated .While each experimental root
was coated with one layer of nail varnish and two
layers of sticky wax except for the apical 2mm.
Indian ink was used as leakage indicator for all
groups (10).A puncher was used to make hole in
the center of the rubber cap to create space into
which the coronal third of each root passed and
fixed to rubber cap. The apical 3 to 4 mm of each
root was immersed in a glass vial containing
Indian ink and deposited in an incubator at 37ºC
for a week. At the end of this period, the roots
were removed from the ink and washed under
running water in a position opposite to the apical
foramen for one minute. The sticky wax was
scraped from the root surface with a lacron carver
and washed again under running water (10).
Clearing process: The roots were decalcified (the
tooth can be pricked by sewing pin) with 5%
nitric acid for a period of 5 days, renewing the
acid daily. The roots were then washed under
running tap water for 30 minutes and dehydrated
by 99-100% ethyl alcohol for 3 days with daily
change of alcohol, and then all the roots became
transparent by immersion in methyl salicylate for
24hours (11).Linear dye penetration was measured
from the apical foramen to the maximum
extension of the dye using light stereomicroscope
Figure 1: The cleared sample of Real Seal 1
bonded obturation.
RESULTS
Table 1: Descriptive statistic of analysis for
experimental groups
Group N Mean S.D
SE Min max
1 13 0.4385 0.08697 0.02412 0.30 0.60
2 13 0.8692 0.16013 0.04441 0.40 1.00
3 13 0.5115 0.13095 0.03632 0.30 0.75
4 13 0.9154 0.08987 0.02493 0.80 1.00
Table 1 shows that, group 1 (lateral condensation
of Gutta-percha) have the lowest mean value of
dye penetration (0.4385) while the highest mean
value of dye penetration was for group 4 (Real
Seal 1) (0.9154). The rest values of other groups
were fluctuation between these values. To identify
the presence of statistically significant difference
for apical dye penetration between groups,
ANOVA test and t- test was carried on. The
results of t-test showed that there is a high
significant difference between all the groups
except for 1&3 and for2&4 the difference was
non-significant.
DISCUSSION
Three dimensional sealing of all portals of exist
present in the root canal system have been the
ultimate goal of different obturation materials and
techniques for many decades. Perfect adhesion
qualities achieved by newer bonding systems
tempted clinicians to adopt such technology in an
attempt to provide better seal for the root canal
system. A new resin obturating materials
“RealSeal1” was tested in the present study for its
ability to provide three dimensional sealing for
root canals. In this study the maxillary first molar
have been used ,the palatal roots were sectioned at
the furcation area to eliminate the variables in
access preparation design, since if the crown
present each tooth would1 and to get flat
reference point for measurements(12).Root canals
were prepared using ProTaper hand system
23
Vol. 24(2), 2012
al.,(27),they found that the new RealSeal1 material
(carrier-based Resilon) showing significantly
better sealing ability than the traditional carrierbased gutta-percha systems, this may be explained
by different evaluation method because they used
fluid filtration method and also disagree with
study conducted by Duggan et al.,(28) that found
that RealSeal1 appeared to resist bacterial
penetration more effectively than Thermafil this
disagreement may be attributed to their study
which is carried on a dog model after inoculation
coronally for 4 months.
3. Resilon, Gutta-Percha and Thermafil
The Resilon showed higher leakage value and a
highly significant difference was found with
gutta-percha and Thermafil groups, this may be
related to the same reasons that are mentioned in
paragraph 4.2, in addition to that inadvertent
stripping of sealer off the canal wall during
placement of cones (29, 30) and disruption of the
maturing resin root dentin bond during lateral
condensation or other technique(29, 30).The results
of present study were in agreement
with(31,32,33)and disagreed with Lumnije et al.(34)
they found that Resilon had less dye penetration
in comparison with gutta-percha and this may be
related to different type of sealer used and
different method of evaluation because they used
dye
extraction
determined
with
spectrophotometer. Wedding et al.(35) found that
Resilon exhibited a statistically significant
increased resistance to fluid movement compared
with gutta-percha and AH-26 sealer. This may be
due to different method of preparation and
different evaluation methods because they used
fluid filtration microleakage test.
4. Gutta-percha and Thermafil :In this in vitro
study, lateral condensation of gutta-percha group
show the least leakage with non-significant
difference with Thermafil group which they
provides best apical sealing .This finding was in
agreement with(36-38,10,39)while these results
disagreed with Inan et al.(40)found that Thermafil
have the lowest mean leakage values than the
highest were observed for lateral condensation of
gutta-percha., this may be attributed to difference
evaluation methods because they used
electrochemical evaluation .
because it provide minimum degree of apical
microleakage when compare with Rotary
ProTaper(13).EDTA was used as irrigant in order to
remove the smear layer because many studies
advocate its removal to reduce microleakage(14)
also deionized water is used as a final irrigant
according to manufacturer instruction. AH-26
sealer was selected and used in this study because
have the lowest leakage value compared with
other types of endodontic sealer (15).SE Real Seal
sealer have been used with a synthetic polymerbased core material (Real Seal 1, Resilon) a
according to the manufacturer instruction.
4.2
Leakage studies constitute a major part of
contemporary endodontic research. .The most
common method used remains the measuring of
liner penetration of dye, but the nature and
amount of leakage observed with this technique
cannot be extrapolated to an in vivo situation.
Measurements of dye penetration were made after
decalcifying and clearing the root which it renders
the root transparent, enables three dimensional
observation of the dye penetration, which can be
recorded to its maximum extent and also evaluate
whether or not associated with porosities, the
presence of empty spaces and stripping of guttapercha from solid core system(16).This explains
using
clearing
method
for
measuring
microleakage for this study. This method
commonly used because it is easily accomplishes
and does not require sophisticated materials (17-19).
1. Real Seal 1 and Resilon: In this in vitro study,
the highest mean of leakage value was observed
in RealSeal1 and Resilon with no significant
differences, this might be related to same
composition of materials and both contain
methacrylate monomer.
2. Real Seal 1, Gutta-Percha and Thermafil:
The Real Seal 1 showed the most leakage value
with highly significant difference was found with
gutta-percha and Thermafil groups. This might be
related to that the methacrylate-based materials
undergo volumetric shrinkage during the
polymerization process(20-22) also the root canal
have high cavity configuration factor that
contribute to polymerization stresses created by
resin-based materials along root canal walls(23).
Tay et al.(24)found that polymerization of the
sealer may be promoted by heat generated during
softening of the material. Another plausible
explanation for high leakage value is that the resin
sealer should be light –cured for 40 seconds to
create an immediate coronal seal according to
instruction, this prevents stress relief by resin flow
and the resin sealer may detach from dentin walls
thus creating interfacial gaps(25, 26). The results of
present study disagreed with Testarelli et
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Vol. 24(2), 2012
The effect of two types
The effect of two types of disinfectant on shear bond
strength, hardness, roughness of two types of soft liners
Rola W. Abdul-Razaq B.D.S., M.Sc. (1)
ABSTRACT
Background: Poor oral hygiene results in accumulation of dental plaque and dental biofilms, especially in elderly
with denture, regular cleaning of the dentures using chemical or physical methods can minimize the risk of
(stomatitis) in denture users. The aim of this study was to evaluate the effect of two types of disinfectant on some
mechanical properties of two types of soft liners.
Materials and methods: 180 specimens from 2 types of soft liners (Mollosile, Viscogel) were prepared and divided into
2 major groups, mollosile group, viscogel group for each test and each major group is divided into 3 subgroups, each
subgroup includes 10 specimens. Hardness and roughness test specimens were consist of two discs, acrylic disc with
dimensions(4mm,15mm)thickness, diameter respectively and soft liner disc with dimensions (2mm,15mm) thickness,
diameter respectively. For shear bond test, specimens were prepared from two blocks of acrylic measuring (75mm,
25mm, 5mm)length, width, depth respectively with stopper (3mm) and handle of (13mm) thickness and soft liner
material in the space between the two acrylic blocks. All specimens were stored in distilled water for 24 hours at 37Co
then they were immersed into water(control group) , Solo, Chlorhexidine 0.2 % disinfectant (test groups) for 8 hours to
simulate the weekly exposure time of soft liner with disinfectant. A profilometer device was used to measure the
roughness property and Shore A for hardness property and Micro-computer controlled electronic universal testing
machine for shear bond property.
Results: The results revealed that there was a significant difference in roughness mean values for each soft liner after
immersed in disinfectant solutions while there was no significant difference in mean values of (hardness, shear bond
strength) for each soft liner after immersed into disinfectant solutions.
Conclusion: Disinfectant solutions (SOLO, CHLORHEXIDINE) had no effect on hardness and shear bond strength of soft
liners (MOLLOSILE, VISCOGEL) while they had effect on surface roughness by decreasing the surface roughness of
these soft liners which is a favorable condition.
Keywords: Soft liner, Disinfectant, Roughness, Hardness, Shear bond. (J Bagh Coll Dentistry 2012;24(2):27-31).
INTRODUCTION
materials are considered to be useless (6).
Prosthesis have been identified as a source of
cross contamination between patient and dental
personal, so chemical disinfectant are a
recommended method to prevent cross
contamination when used after removal and
before insertion of prosthesis into mouth (7). A
denture disinfectant method should be effective
for inactivation of microorganisms without
adverse effects on the denture materials (8). The
aim of this study was to investigate the effect of
chemical disinfectant (solo, chlorhexidine 0.2%)
on shear bond strength, hardness, surface
roughness of two types of soft liners (mollosile,
viscogel) .
The clinical use of soft denture lining materials
was first reported in 1943(1).Soft lining materials
are able to form an absorbing layer on the part of
the denture in contact with oral mucosa and this
allow less traumatic transmission of occlusal
forces(2). The use of soft liners has become
increasingly popular for providing comfort for
denture wearers. Soft liners are often used for
patients who cannot tolerate a conventional
denture base (3). These materials have several
disadvantages including color stability, resiliency,
abrasion resistance, bond strength and porosity (4).
The ideal hardness or softness for providing a
greater comfort to the patient can be obtained with
the use of soft materials, so hardness is important
property for resilient material and should remain
constant for a long period so that the material can
efficiently fulfill their functions. Surface
roughness is also important property; a rough
surface can lead to biofilm accumulation and
colonization of Candida albicans, which is the
major etiological factor for denture-induced
stomatitis .The denture made from two different
materials can only be successful if there is an
adequate bond between the materials (5), so the
favorable properties of a denture liner in the
absences of good adhesion to denture base
Totally 180 specimens were prepared from 2
types of soft liner (mollosile, viscogel) both of
them are room temperature curing soft liner and
240 specimens of heat cure acrylic (Major dent,
Italy) were prepared for surface roughness,
hardness, shear bond tests. They were divided into
2 major groups (molosile , viscogel) group for
each test,
each major group includes 30
specimens and divided into 3 subgroups, each
subgroup includes 10 specimens: Mw: mollosile
specimens in water. Ms:mollosile specimens in
solo.Mc: mollosile specimens in chlorhexidine.
(1) Assistant lecturer, dep. of prosthetic dentistry, college of
dentistry, Baghdad University.
27
Vol. 24(2), 2012
The same specimen groups for viscogel material.
Surface roughness and Hardness test: The
specimens of these tests consist of a disc of
(15mm) in diameter and (4mm) in thickness of
heat cure acrylic resin with (2mm) thick layer of
the soft liner bonded to each disc. A brass pattern
was constructed in a form of disc (15mm, 4mm)
diameter, thickness respectively for preparation of
acrylic disc and a silicone mould was prepared
from which a wax patterns with dimensions of
(15mm, 2mm) diameter, thickness respectively
were produced. The disc of wax was placed on the
disc of acrylic and both of them were invested as
one piece inside the lower half of conventional
dental processing flask that was filled with dental
stone mixed according to the manufacturer’s
instructions (dental stone Elite model, Italy) to
prepare a mould for final specimens, a piece of
glass was placed over the wax so the level of wax
is with the level of stone and smooth surface of
soft liner is created, after setting of stone, wax
elimination was done and the mould was cleaned
and left to dry then the soft liner was mixed
according to the manufacturer’s instructions and
applied into the mould by spatula, the flask was
closed and pressure was applied by using
hydraulic press up to 100 Kpa then the pressure
was released and the flask was left for bench cure.
After complete curing the specimens were
removed and by using sharp knife the excess of
material was removed after that the specimens
were stored in distilled water for 24 hours at 37Co
then they were immersed in disinfectant solutions
(solo, chlorhexidine 0.2 %) for 8 hours to simulate
the weekly exposure of soft liner with
disinfectant(3). After that the specimens were
removed and tested. A profilometer device was
used to study the surface roughness property of
each soft liner, and Shore A hardness tester was
used to measure the indentation hardness of each
soft liner.
Shear bond strength test: The specimens of this
test consist of 2-heat cure acrylic blocks with
dimensions of (75mm, 25mm, 5mm) length,
width, depth respectively with stopper of (3mm)
and handle of (13mm) in thickness. A metal
pattern was constructed with the same dimensions
mentioned above to prepare acrylic specimens,
each soft liner was mixed according to the
manufacturer’s instructions and applied by spatula
into the space between the two acrylic blocks, any
excess of material was removed by using sharp
knife and the specimen was put under weight
(200)g for stability and left for bench cure, after
complete curing the specimens were stored in
distilled water for 24 hours at 37Co, then the
specimens were immersed into disinfectant
solutions (solo, chlorhexidine 0.2 %) for 8 hours
to simulate the weekly exposure of soft liner with
disinfectant(3). After that the specimens were
tested for shear bond strength using Microcomputer controlled electronic universal testing
machine and subjected to shear load with cross
head speed (2mm/min) using load cell capacity
(10 Kn), shear bond was calculated according to
the following formula:
Bond strength = F(n)/A(mm)2 (ASTM,
specification D-638m, 1986).
RESULTS
Mw: mollosile specimens in water
Ms: mollosile specimens in solo
Mc: mollosile specimens in chlorhexidine
Vw: viscogel specimens in water
Vs: viscogel specimens in solo
Vc: viscogel specimens in chlorhexidine.
Roughness test:
Table1: Descriptive statistics for surface
roughness test in (µm) for mollosile material.
Group Sample No. Mean (µm) S.D.
10
1.25000 0.55025
Mw
10
0.58000 0.15491
Ms
10
1.22000 0.50508
Mc
Table 1 shows the mean values and the S.D. of
surface roughness for mollosile material, the
highest mean value was for water group and the
lowest mean value was for solo group.
Table 2: Analysis of variance (ANOVA) test
for surface roughness for mollosile material
Source
Between
groups
Within
groups
d.f.
Mean
square
2
1.432
27
0.193
FP-Value
Value
7.38
0.0028
Sig.
H.S
P>.05(non-significant),p<.05(significant),p<.01(highly
significant).
Table 3: L.S.D. test between control and test
groups of mollosile material for surface
roughness test
Groups
mw*ms
mw*mc
ms*mc
Difference between
mean
0.67
0.03
0.64
L.S.D.
0.05
Sig.
0.4041
H.S.
N.S.
H.S.
ANOVA test was described in table 2 which
shows highly significant difference for mollosile
material groups. L.S.D test in table 3 shows a
28
Vol. 24(2), 2012
highly significant difference for mw*ms and
ms*mc while non significant difference for
mw*mc.
Table 8: Descriptive statistics for hardness
test for viscogel material
Group Sample No. Mean S.D.
10
41.6000 7.08989
vw
10
41.7000 3.49761
vs
10
41.8000 6.35609
vc
Table 4: Descriptive statistics for surface
roughness test in (µm) for viscogel material
Group Sample No. Mean (µm) S.D.
10
2.89000 0.45570
Vw
10
2.63000 0.08232
Vs
10
0.86000 0.47187
Vc
for hardness for mollosile material
Source
Table 4 shows the mean values and the S.D. of
surface roughness for viscogel material, the
highest mean value was for water group and the
lowest mean value was for chlorhexidine group.
Between
groups
Within
groups
Between
groups
Within
groups
d.f.
Mean
square
2
12.202
27
0.1457
FP-Value
Value
<.0001
H.S
Between
groups
Within
groups
significant).
2
0.6333
27
2.4481
FP-Value
Value
0.26
Sig.
0.7739
N.S
d.f.
Mean
square
2
0.1000
27
34.300
FP-Value
Value
0.00
Sig.
0.9971
N.S
significant).
Table 6: L.S.D. test between control and test
groups of viscogel material for surface
roughness test.
ANOVA test was described in table 9,10 for
mollosile and viscogel materials respectively
shows non significant difference between control
group and test group for both materials.
Difference L.S.D.
Sig.
between mean 0.05
0.26
N.S.
vw*vs
2.03
0.3503 H.S.
vw*vc
1.77
H.S.
vs*vc
Groups
Shear bond strength test:
Table 11: Descriptive statistics for shear
bond strength test in (N/mm2) for mollosile
material
Mean
S.D.
Group Sample No.
N/mm2
10
0.09300 0.00483
mw
10
0.09700 0.00483
ms
10
0.09600 0.00516
mc
ANOVA test was described in table 5 which
shows highly significant difference for viscogel
material groups. L.S.D. test in table 6 shows
highly significant difference for vw*vc and vs*vc
while non significant difference for vw*vs.
Hardness test:
Table 7, 8 shows the mean values and S.D. of
hardness test for mollosile and viscogel material
respectively, in general the results for control and
test group showed nearly the same mean values
for both materials.
Table 12: Descriptive statistics for shear
bond strength test in (N/mm2) for viscogel
material
Group Sample No.
Table 7: Descriptive statistics for hardness
test for mollosile material
mw
ms
mc
Group Sample No. Mean S.D.
10
26.3000 1.41813
mw
10
26.6000 1.71216
ms
10
26.8000 1.54919
mc
Mean
square
for hardness for viscogel material
Sig.
Source
83.8
d.f.
significant).
for surface roughness for viscogel material
Source
10
10
10
Mean
S.D.
N/mm2
0.06600 0.00516
0.06500 0.00527
0.06400 0.00516
Table 11,12 shows the mean values and S.D. of
shear bond strength for both mollosile and
viscogel respectively, in general the results for
control and test groups showed nearly the same
mean values for both materials.
29
Vol. 24(2), 2012
liners (Garcia et al,2003) stated that when these
materials were immersed in cleansing products a
loss of soluble components occurred leaving
empty spaces or bubbles which is responsible for
surface roughness, these bubbles or voids
underwent an increase in size that resulted in
crater, the limits of the craters are probably
smaller when compared to the bubbles leaving
specimens smoother and these differences
between the two materials are attributed to the
different chemical structure of the 2 soft liners
(acrylic-base and silicone-base); therefore they
have different properties and behaviors in the
cleansers(14) , also changes of surface roughness of
materials varied depending on both immersion
time and types of cleansers. Hardness is one of the
most challenging factors in the use of complete
denture liners, the greater the softness, the greater
the extension in absorbing the impact effect, thus
less hardness is desirable characteristic for soft
liners. In this study there is a non significant
difference in hardness property for both materials
when immersed in both types of disinfectant
solutions, this results can be attributed to type of
cleanser and type of soft liner because the type of
denture cleansers are known to be important in
assessment of the compatibility of cleansers with
soft liners (15) this result agrees with(Azevedo et
al, 2006) who found that there is no significant
changes in hardness regardless of disinfectant
solutions used, so it appeared that in this respect
the materials were likely to be equally effective
clinically.
Bond strength property of reline materials are
very important for their Cushioning effect which
allow for more even distribution and maintenance
of material shape, de-bonding results in
unhygienic condition at the de-bonded region and
causes functional failure of prosthesis(17) , both
materials shows a non significant difference in
shear bond strength when immersed in both
disinfectant solutions, this can explain as,
viscogel
material
is
polymethyl/ethylmethacrylate and acrylic is
polymethyle methacrylate , so according to
(Garcia et al,2003) chemical adhesion may be
explained by similar chemical composition of
acrylic resin and resilient liners , so the shear
bond was not affected by the immersion in
disinfectant solutions. Mollosile material is
silicone polymer based denture liner, the adhesion
between mollosile and acrylic resin can be
achieved by using an adhesive which is a solvent
that dissolve the PMMA surface, however there is
no chemical adhesion but the shear bond by using
adhesive was not affected by the 2 types of
disinfectant solutions which is attributed to the
for shear bond strength for mollosile
material
Source
Between
groups
Within
groups
d.f.
Mean
square
2
.00004
27
.00002
FP-Value
Value
1.77
0.1891
Sig.
N.S
significant).
for shear bond strength for viscogel material
Source
Between
groups
Within
groups
d.f.
Mean
square
2
.00001
27
.00002
FP-Value
Value
0.37
0.6943
Sig.
N.S
significant).
ANOVA test was described in table 13,14 for
mollosile and viscogel materials respectively
shows a non significant difference between
control group and test groups for both materials.
DISCUSSION
Although chemical denture cleanser have been
considered to be efficacious method to prevent
Candida albicans colonization and denture plaque
formation (9), daily use of denture cleanser can
affect the physical properties of denture acrylic
resin bases and soft liners(10),because when
immersed in soaking solutions or placed in oral
cavity, soft liners undergo two processes, leaching
out of plasticizers and other soluble materials and
sorption of water or salivary components. So the
fluctuation between these two processes affects
the properties of denture liner material (11) . Aging
or changes in physical properties of soft denture
lining materials appear to depend upon their type
or composition (12).
Almost all soft liners became rougher to a greater
or lesser extent by the immersion into denture
cleansers. In this study mollosile material shows
significant difference in surface roughness change
which was decreasing in roughness when
immersed in solo while viscogel material shows
significant difference in surface roughness change
which was decreasing in roughness when
immersed in chlorhexidine. This decrease in
roughness is favorable characteristic for soft liners
because surface roughness is very important
property of reline materials.
This can be
explained by, regarding the roughness of soft
30
Vol. 24(2), 2012
13. Garcia RM, Leon BT, Oliveira VB, Del Bel Cury AA.
Effect of a denture cleanser on weight, surface
roughness and tensile bond strength of two resilient
denture liners. J Prosthet Dent 2003; 89: 489-94.
14. Abdul-Kareem AA. Effect of denture cleansers on
sorption, solubility, tensile bond strength and surface
roughness of two soft denture lining materials. A
master thesis, Prosthetic Department, University of
Baghdad 2006.
15. Jin C, Nikawa H, Makihira S, Hamada T, Furukawa
M, Murata H. Changes in surface roughness and color
stability of soft denture lining materials caused by
denture cleansers. J Oral Rehabil 2003; 30: 125-30.
16. Azevedo A, Machado AL, Vergani CE, Giampaolo
ET, Parvarina AC, Magnani R. Effect of disinfectants
on hardness and roughness of reline acrylic resins. J
Prosthodont 2006; 15(4): 235-42.
17. Kawano F, Dootz ER, Koran A, Craig RG.
Comparison of bond strength of six soft denture liners
to denture base resin. J Prosthet Dent 1992; 68: 36871.
type of denture cleanser and type of soft liner and
the compatibility between them as mentioned
before the type of denture cleanser is important in
assessment of the compatibility of cleanser with
soft liner, also changes in physical properties of
soft liner depend upon their type and composition.
REFERENCES
1. Tylman S. The use of elastic and resilient synthetic
resins and their copolymer in oral, dental and facial
prosthesis. Dental Digest 1943; 49: 167.
2. Brozek R, Koczorowski R, Rogalewice R, Voelkel A,
Czarnecka B, Nicholson JW. Effect of denture
cleansers on chemical and mechanical behavior of
selected soft lining materials. Dent Mater J
2011;27(3):281-90.(IVL)
3. Sarac D, Sarac YS, Kurt M, Yuzbasioglu E. The
effectiveness of denture cleansers on soft liners
colored by food colorant solutions. J Prosthodont
2007; 16(3): 185-91.
4. Anusavice KJ. Phillips’Science of dental materials 11th
ed. Philadelphia: Saunders; 2003. p. 269-71.
5. Segundo ALM, Pisani MX, Paranhos HFO, Souza RF,
Lovato CHS. Effect of a denture cleanser on hardness,
roughness and tensile bond strength of denture liners.
Braz J Oral Sci 2008; 7(26): 1596-601.
6. Mese A, Guzel KG, Uysal E. Effect of storage
duration on tensile bond strength of acrylic or siliconebased soft denture liners to a processed denture base
polymer. Acta Odontal Scand 2005; 63: 31-5.
7. Hamouda IM, Ahmed SA. Effect of microwave
disinfectant on mechanical properties of denture base
acrylic resin. J Mechnical Behavior of Biomedical
Materials 2010; 05: 002.
8. Machado AL, Breeding LC, Vergani CE, Prerez
LEDC. Hardness and surface roughness of reline and
denture base acrylic resins after repeated disinfection
procedures. J Prosthet Dent 2009; 102(2): 115-22.
9. Nikawa H, Ntshlmura H, Yamamoto T, Hamada T,
Samaranayakl LP. The role of saliva and serum in
Candida albicans biofilm formation on denture acrylic
surface. Microbial Ecology in Health and Disease,
9:35.
10. Nikawa H, Iwanaga H, Hamada T, Yuiita S. Effect of
denture cleansers on direct soft denture lining
materials. J Prosthet Dent 1994(a); 72: 657.
11. Sinobad D, Murphy WM, Hugget R, Brooks S. Bond
strength and rupture properties of soft denture liners. J
Oral Rehabil 1992; 19: 151-60.
12. Wagner WC, Kawano F, Dootz ER, Koran A.
Dynamic viscoelastic properties of processed soft
denture liners part I. J Prosthet Dent 1995(a); 73: 471.
31
Vol. 24(2), 2012
Immunohistochemical detection
Immunohistochemical detection to evaluate the biological
role of Ti implants coated by a combination of fibronectin
protein and hydroxyapitate (EPD) (in vivo study)
Athraa Y.Al-Hijazi, B.D.S., M.Sc., Ph.D. (1)
Thair L-Al-Zubaydi, M.Sc., Ph.D. (2)
Eman I. Mahdi, B.D.S., M.Sc. (3)
ABSTRACT
Background: physicochemical and biochemical coating techniques that are investigated now a day to enhance
bone regeneration at the interface of titanium implant materials. The combination, however, of both organic and
inorganic constituents is expected to result into truly bone-resembling coatings and as such to a new generation of
surface-modified titanium implants with improved functionality and biological efficacy. This research was conducted
to study the expression of osteocalcin and growth hormone receptor as bone formation markers in coated and
uncoated implant in interval periods (3days,1,2and 6 weeks).,
Materials and methods: Commercially pure titanium (CpTi) implants coated with hydroxyapatite by EPD method and
with fibronectin protein, were placed in the tibia of (16) New Zeland white rabbits , immunohistochemical tests for
detection of expression of osteocalcin and growth hormone receptor were performed on all the implants of both
control and experimental groups (3days,1,2 and 6 weeks) healing intervals. Mechanical test (torque removal test)
was performed as an indicator for the presence of osseointegration and as a test for the mechanical property of
bone-implant interface to be primarily propping the interface machanics.
Results: The removal torque mean values in all studied groups uncoated and coated were increasing with
advancing time (higher at 6 than 2 weeks periods) and coated implant showed high value in comparsion to control.
Result shows that Immunohistochemical findings revealed high positive expression range from strong to moderate for
osteocalcin and growth hormone receptor in coated implant in comparison to uncoated. These results indicating
that a mixing of bioactive HA ceramic and FN increased the activity of coated layer which improved the bone
formation and maturation in bone-implant interface and enhance mechanical interlocking with bone.
Conclusions: The present study concludes that organic and inorganic surface modification for titanium implant
surface by HA and FN enhances bone formation and increase osseointegration.
Key words: fibronectin protein, dental implant biochemical bone markers osteocalcin, growth hormone receptor. (J
Bagh Coll Dentistry 2012;24(2):32-38).
Fibronectin is a large adhesive glycoprotein highmolecular weight extracellular matrix involved in
many cellular processes, including tissue repair,
embryogenesis, blood-clotting,cell migration/
adhesion growth and wound healing. Coating of
dental implant with FN enhanced osteoblast
differentiation and increases the rate of bone
formation at the site of implantation
Osteocalcin is a bone specific non-collagenous
protein. Osteocalcin is synthesized by osteoblst
during bone formation and deposited mainly in
the extracellular matrix
It is consider as
aspesific marker of osteoblast cells because
osteocalcin is involved in the process of osteoid
minerlization, the protein is expressed mainly
during phase of bone formation Growth
hormone receptor (GHR) is a transmembrane
receptor for growth hormone. Binding of GH to
GHR promotes receptor dimerization and initiates
a cascade of events leading to protein
phosohorylation and activation of nuclear protein
and transcription factors in osteoblasts
GH has
an effect on the proporations of hematopoietic and
mesenchymal progenitor cells in the bone
INTRODUCTION
The clinical success of dental implants is directed
by implant surface and bone cell responses that
promote rapid osseointegration and long-term
stability
Several surface modification have
been
proposed
in
order
to
promote
osseointegration
of
titanium
implants
Hydroxyapatite (HA) is one of the most
extensively used synthetic calcium phosphates for
bone replacement and in dental field because of
its chemical similarities to the inorganic
Hydroxyaptite
component of bone and teeth
coated titanium implant have been becoming
more popularly because long-term good clinical
results and the quick new bone formation around
the implant of implantation occurs. These coating
have been found to accelerate intial stabilization
of implants by enhancing bony ingrowth and
stimulating osseuos apposition to the promoting a
rapid fixation of the devices to the skeleton
(1) Professor, Oral Histology& Biology, College of Dentistry.
(2) Senior Scientific Researcher, Ministry of Science
Technology, Baghdad, Iraq.
(3) Assistant Professor, Oral Histology & Biology, College of
Dentistry.
Oral Diagnosis
32
Vol. 24(2), 2012
accordance with the manufacture instruction
(Abcam UK).
marrow, and that GH is essential for both the
induction and later progression of osteogenesis
RESULTS
The result in this study show a significant higher
torque was needed to remove implant
electrophoreticall coated with HA and with
fibronectin protein (HEF) in (15.31N.cm, 30.28
N.cm) 2 and 6 weeks of implantation respectively
than the uncoated implants. all values were
increasing with advancing time and significant
differences between different time periods was
present,
P≤0.000(table1).
Radiolgraphical
evaluation revealed cortical bone thickness with
clear radioopacity around the coated implant
(Figure 1).
Immunohistochemical
examination
for
osteocalcin expression of implant in different
interval periods.
Titanium implant coated with fibronectin
protein and HA shows strong positive
immunohistochemical localization of osteocalcin
and many progenitor cells are present nearby
which shows positive reaction to osteocalcin at
the site of implant of 3 days duration (Figure 2,3).
In one week duration, moderate positive
immunohistochemical localization of osteocalcin
protein in rabbit tibia in implant coated with HA
and fibronectin protein is illustrated. Woven bone
formation with positively stained osteoblast cell
neucli, active fibroblast cells and in the
extracellular matrix of woven bone (Figure 4).
At 2 weeks duration section of implant coated
with HA and fibronectin protein shows numerous
bone trabeculae within active woven bone, stain
negatively as shown blue coloure with counter
haematoxyline stain while formative cells shows
positive stain (Figure 5). The high power view
shows positive stain for the progenitor cell (Figure
6).
Threads of Ti implant coated with HA&FN for
6weeks duration shows positive DAB stain in
osteoblast cell for osteocalcin (Figure 7).
Immunohistochemical examination for growth
hormone receptor expression of implant in
different interval periods.
Primitive bone formation around fibronectin
coated implant of three days duration of
implantation
and
strong
positive
immunohistchemical stain for GHR is seen in
progenitor cells and reticular cells (Figure 8).
Bone section at implant coated with HA and
fibronectin protein for 1 week duration shows area
of woven bone tissue strong positive localization
of GHR in progenitor osteoblast cell and in
extracellular matrix (Figure 9).
Materials
CpTi readymade implants from friatic
company were modified and machined in
diameter about 3.5mm, length of 8 mm (5mm was
threaded and 3mm was flat). Fibronectin protein
(Applied by Biosystem, CA, U.S.A).
Hydroxyapatite powder (Merck, Germany).
-Ethanol 99.8% (GFs chemicals, Germany).
-Hydrogen peroxide black
-Protein black.
-Biotinylated goat anti-mous IgG
-Streptavidin peroxidase
-DAB chormogen
-Monoclonal antibodies were used in the present
study (OC4-30, ab13418)(MAB 263,ab 11380)
respectively.
-Abcam anti mouse HRP/DAB detection kit
(ab64259-15).
Methods
Electrophoretic EPD coating was applied on
dental implants suspension for HA was prepared
by adding HA powder to the solvent which was
ethanol 100g/liber in a baker under continous
stirring .sixteen (16) Newzeland rabbits aged (1012 months) were used in this study they were
divided into four groups for (3days 1,2 and 6
weeks) healing intervals (4) animals for each
period. Animals were generally aneasthesised and
atramatic surgical technique was performed to
prepare two holes in the tibia FN coated implant
was inserted in one hole and uncoated implant
(control) placed in the second one.
In the left tibia HA coated implant was
inserted in one hole and uncoated implant placed
in the second one. Animals we sacrificed after
3ays 1,2 and 6 weeks.
Immunehistochemical examination(IHC)
All tissue specimen samples and controls,
were fixed in 10% neutral formation and
processed in a routin paraffin blocks. Each
formalin-fixed-paraffin-embedded specimen had
serial section were prepared as follows: 5µm
thickness sections were mounted on clean glass
slides for routine haematoxylin and Eosin staining
(H&E), from each block of the studied sample and
the control group for histopathological reexamination. Other 4 sections of 5µm thickness
were mounted on positively charged microscopic
slides to obtain a greater tissue adherence for
immunohistochemistry. The procedure of the IHC
assay adapted by this study was carried out in
Oral Diagnosis
33
Vol. 24(2), 2012
Bone trabeculae with active primitive bone
formation in titanium implant coated with HA and
fibronectin protein for 2 weeks duration marrow
tissue of different sizes showing positive stain are
enclosed by anastemosing trabeculae, osteoblast
seen at the peripharyes and huge neumerous of
osteocytes are located within bone matrix , both
types of cells show positive stain, the trabeculae
of bone itself are stained negatively (Figure10).
After six weeks of implantation mature lamellated
bone is deposited at implant site, it shows
negative DAB stain for GHR, some osteocytes are
embedded within bone matrix osteon canal and in
endostium area stain positively (Figure 11).
thickening (corticalization” process
was
observed, despite the non-functioning of these
implants in agreement with the finding of
Hammad et al
It may be suggested that this
bone response constitutes just a step in the entire
bone healing process even in the absence of load.
Immunohistochemical findings, osteocalcin of
that Osteocalcin are positively expressed in both
coated and uncoated implants and for all coating
material in different intervals period. Bone
marrow tissue is positively stained indicating
osteocalcin protein localization. Strong positive
expression of osteocalcin was noted with agroup
of implant coated with FN and also coated with
HA (HEF).
This is in agreement with
(5)
Timothy et al and Tardieu (10) they revealed that
coating of implant with FN protein enhanced
osteoblastic differentiation and minerlization in
bone marrow stromal cell, also FN. Protein
function to stimulate bone formation by moving
adult stem cells from a site far away from the
surrounding of the implant into the implanted site
by chemotaxis so as to differentiation into
osteoblasts .In 6 weeks duration, osteocalcin
shows negative immunohistochemical stain for
localization of , osteocalcin but it shows positive
expression on osteoblast lining the surface of
osteon and when there is area of bone formation.
These findings are in agreement with Muramatsu
et al, 2005
study which indicated that agreater
osteocalcin expression is observed at 14 and 21
days characterization the periods when intense
minerlization of the bone tissue occurs during
alveolar bone healing process. In this study GHR
shows positive expression in coated and uncoated
implants in all healing interval periods. In two
week duration osteoid tissue formed around
titanium implant shows positive localization of
GHR in the formative cell progenitor that are
irregularly arranged within primitive bone
formed. After 6 weeks of implantation osteon
canal and in endostium area shows positive
localization of GHR.
The differences in the bone reaction between
coated and uncoated implants not only suggesting
a high osteoconductive potential of the coated
material but also it’s osteoinductivity, the
osteoconductive action was seen in all coated
groups specially for that coated with mixing of
FN and HA where bioactive properties can be
seen by the presence of fibrovascular tissue,
osteoblast activity and expression of bone marker
new bone formation, these finding was in
agreement with Al-Mudarris et al (16) and
Hammad et al (17)
DISCUSSION
In this study we use biological organic material
represented by fibronectin coated the implant and
others used in combination with HA. The general
histologic finding abserved that all surface
investigated
were
biocompatible
and
osseoconductive. Fibronectin protein is biological
glycoprotein act as osseoinductive material, it
enhance recruitment of progenitor cell to its area
and activate its differentiation into osteoblast cells
once these cells deposit organic matrix specially
collagen fiber, the FN will facilitate the adherence
of these cells to fiber, these biological sequence
facilitate and accelerate bone formation
process
Modification effect of HA in coating process that
enhance progenitor cell to differentiate to
fibroblast in addition to osteoblast and also
reticular cell activation which showed reticular
fiber deposition when needs for more
investigation
These results indicating that active bone
apposition with strong attachment was achieved
on the surface of implant coated with HA and FN
protein which may be the reason for higher
removal torque value. The possible explination for
these finding is that surface chemistry is
effectively influenced osseointegration and the
higher torque value may be interpreted as an
increase in the strength of bony integration at the
bone, implant interface. This is in agreement
within work of Suh et al
The radiographic examination shows increase in
the thickness of cortical bone at experimental
implant sites indicating increased bone formation
and maturation around the coated implants for the
six weeks duration of implantation. In studied
groups of the present study, following insertion of
a biocompatible CpTi implant into cortical bone
the implants were not submitted to any load, in
most of the implants the presence of such
Oral Diagnosis
34
Vol. 24(2), 2012
REFERANCE
1. Lee JH, Nam H, Ryu HS, Seo JH, Chang Bs, Lee CK.
Bioactive ceramic coatings of cancellous screws
improves the osseointegration in the cancellous bone.
J Orthop Sci 2011; 16:291-7.
2. Xiao SJ, Kenausis G, Textor M. Biochemical
modification of titanium surfaces. In: Berunette DM,
Tengvall P, Textor M, Thomsen P, editor. Titanium in
medicin. Berlin : Spreingler Verlay, 2001;417-53.
3. Hung J, Li X, Koller GP,. Silvio LD.
Electrohyrodynamic deposition of nan-titanium doped
hydroxyapatite coating for medical and dental
application. J Mater Sci Mater Med 2011; 22:441-496.
4. Obadia L, Jullien M, Quillards, Rouillion T, Pilet P,
Guicheux J, Bujoli B, Bouler JM. Na-doped βtricalcium phosphate: physic chemical and in vitro
biological properties. J Mater Sci Mater Med
2011;22:593-600.
5. Timothy AP, Catherine DR, Kellie LB, Andress JG.
Simple application of fibronectin- mimetic coating
enhances osseointegration of titanium implants. J cell
Mol Md 2009; 13(8B):2602-12.
6. Caoa T, Henga BC, Yea CP, Liua H, Toha WS,
Robsonb P,
Lib P, Hong YH. Osteogenic
differentiation within intact human embryoid bodies
result in a marked increase in osteocalcin secretion
after 12 days of in vitro culture, and formation of
morphologically distinct nodule-like structures Tissue
and Cell 2008; 37(4): 325-34.
7. Lee NK, Sowa H, Hinoi E, Ferron M, Ahn JD,
Confavreux C, Dacquin R, Mee PJ, McKee MD, Jung
DY, Zhang Z, Kim JK, Mauvais-Jarvis F, Ducy P,
Karsenty G. Endocrine regulation of energy
metabolism by the skeleton. Cell 2007; 130 (3): 456–
69.
8. Cool SM, Grunert M, Jackson R, Li H, Nurcombe V,
Wters MJ. Role of growth hormone receptor signaling
on osteogenesis from murine bone marrow progenitor
cells. Biochem Biophys Res Commun 2005;
16:338(2):1048-58
9. Jennifer E. Rowland, Agnieszka M. Lichanska, Linda
M. Kerr, White M, Elisabetta M. d’Aniello. ,Maher
SM, Brown R, Teasdale RD,Noakes PG. Waters :In
Vivo Analysis of Growth Hormone Receptor
10.
11.
12.
13.
14.
15.
16.
17.
18.
Signaling Domains and Their Associated Transcripts
Molecular and Cellular Biology, 2005; 25(1): 66-77 .
Maher SM, Brown R, Teasdale RD,Noakes PG.
Waters. In Vivo Analysis of Growth Hormone
Receptor Signaling Domains and Their Associated
Transcripts. Molecular and Cellular Biology 2005;
25(1): 66-77 .
Tardieu P. Process for the preparation of protein
mediated calcium hydroxyapitite (HAP) coating on
metal substrate. Patent application number 12/175812
Assignee council of scientific and industrial research
Internationalclasses: A61L 27/32:A61L27/00 2010.
Jimbo R, Coelho PG, Vandeweghe S, Schwartz-Fiho
HO, Hagashi M, one D, Andersson M, Wennerberg A.
Histological and three-dimensional evaluation of
osseointegration to nano structured calcium
phosphate-coated
implants.
Acta
Biomater
2011;21:20-5.
Suh JY Jeung OY, Chio BJ, Park JW. Effects of a
novel calcium titanate coating on the osseointgration
of blasted endosseous implantatsin rabbit tibiae. ClinOral Implant Res 2007; 17:362-4.
Januario AL, Sallum EA, Toledo S, Sallum AW,
Nocitif HJ. Effect of Calcitonin on Bone Formation
Around Titanium Implant. A histometric study in
rabbits. Braz Dent J 2001;12(3):158-62
Hammed TI, Al-Ameer S.S, Al-Zubaydi TL.
Histological
and
mechanical
evaluation
of
electrophoretic bioceramic deposition on Ti 6AL-7Nb
dental implants. A phD thesis, College of Dentistry,
University of Baghdad 2007.
MuramatsuT, Hamano H, Ogami K, Ohta K, Inoue T,
Shimono M,Reduction of osteocalcin expression in
aged human dental pulp. National Library of Medicine
2005;38 (11):817-21.
AL-Mudarris BA, Salem SAL, Al-Zubaydi TL. The
significance of biometric calcium phosphate coating
on commercially pure titanium and Ti-6AL-7Nb
Alloy.A phD thesis, College of Dentistry University of
Baghdad 2006.
Hammed TI, Al-Ameer S.S, Al-Zubaydi TL.
Histological
and
mechanical
evaluation
of
electrophoretic bioceramic deposition on Ti 6AL-7Nb
dental implants. A PhD thesis, College of Dentistry,
University of Baghdad 2007.
Table 1: Summary Statistics for Removal Torque test in different studied and suggested of
coated materials treated along two weeks and six weeks measured continuously
Torque- test
95% Confidence Interval for Mean
Lower Bound
Upper Bound
8.91
13.30
13.41
17.22
Period
Material
Groups
N
Mean
S.D.
S.E.
After (2)
weeks
FN+HA
(HEF)
R - Control
L1 - Coated
4
4
11.11
15.31
1.38
1.20
0.69
0.60
After (6)
weeks
FN+HA
(HEF)
R - Control
4
18.28
0.60
0.30
17.33
L2 - Coated
4
30.28
0.76
0.38
29.07
Oral Diagnosis
35
Min.
Max.
10.00
14.38
13.13
16.88
19.23
17.50
18.75
31.49
29.38
31.13
Vol. 24(2), 2012
Figure 2: Positive DAB stain
immunohistochemical localization of
osteocalcin protein in site surface of
titanium implant coated with FN and
HA in rabbit tibia for 3 days duration
DAB with haematoxylin counter
stain x 100
Figure 1: Conventional radiographic
view for Ti implant coated with HA
and fibronectin protein for 6 weeks
shows overhang bone on the implant.
Where (C) uncoated and (HEF)
coated with fibronectin protein and
hydroxyapatite.
Figure 4: View for positive
immunohistochemical localization of
osteocalcin protein in nucleous of
osteoblast active fibroblast cells and in
the extracellular matrix of woven
bone deposite around the titanium
implant coated with FN and HA for 1
week duration in rabbit tibia.DAB
with haematoxylin counter stain x 200.
Figure 3: High power view of previous
Figure 2 shows positive brown colour
for DAB stain for stromal cells to
osteocalcin protein DAB with
haematoxylin counter Stain x 200.
Oral Diagnosis
36
Vol. 24(2), 2012
Figure 5: Immunohistochemical view for
localization of osteocalcin protein in
titanium implant coated with FN and HA
for 2 weeks duration shows negative stain
to calcified bone trabeculae as shown blue
stain) and only the formative cells shows
positive stain.DAB with haematoxylin
counter stain x 400.
Figure 6: High magnification view of
previous Figure 2 shows bone trabeculae
(negative stain) and the formation and
progenitor between shows positive stain
DAB with haematoxylin counter stain x
400
Figure 7: Immunohistochemical view of
threads of Ti implant coated with HA and
FN for 6 weeks duration shows positive
DAB stain in osteoblast cells for osteocalcin
protein as it occupies the surface lining the
bone DAB with haemtoxylin counter stain
X200.
Oral Diagnosis
Figure 8: View for positive
immunohistochemical DAB stain for GHR
in titanium implant surface coated with
HA and FN for 3 days duration. DAB with
haematoxylin counter stain x 200
37
Vol. 24(2), 2012
Figure 9: Woven bone view of titanium
implant coated with HA and FN for 1 week
duration shows positive DAB stain for
GHR localized extracellular matrix and in
progenitor osteoblast DAB with
haematoxylin counter stain x 400.
Figure 10: Bone trabeculae view of
titanium implant coated with HA and FN
for 2 weeks duration shows positive DAB
stain for GHR localized only on osteocyte
and osteoblast , while bone itself shows
negative stain note the huge numerous
number of osteocyte DAB with
haematoxylin counter stain x 200
Figure 11: Thread view of titanium
implant coated with HA an FN for 6
weeks duration shows negative stain for
GHR in mature bone and only positive in
the area occupied by osteon canal and in
endostium area DAB with haematoxylin
counter stain x 200.
Oral Diagnosis
38
Vol. 24(2), 2012
Evaluation of 900 mhz
Evaluation of 900 mhz mobile phone effects on palate and
tooth germ development in mouse embryo (histological &
immunohistochemical study)
Faten H. Berto, B.D.S. (1)
Athraa Y. Al-Hijazi, B.D.S., M.Sc., Ph.D. (2)
ABSTRACT
Background Mobile telephones, sometimes called cellular phones (GSM, Global System for Mobile Communication)
or handies, are now an integral part of modern telecommunications. In some parts of the world, they are the most
reliable or only phones available. In others, mobile phones are very popular because they allow people to maintain
continuous communication without hampering freedom of movement.This study was carried out to evaluate the
effects of 900 MHz mobile phone on palate and tooth germ development in mouse embryo for the period of (16th
day, 18th day intrauterine life and one day postnatal life).
Materials and Methods Thirty pregnant Bulb-c Albeno Swiss female mouse (2-3 months of age, 100-125 gm of weight),
were used in the present experiment. Those mice were divided into three groups. The first group consisted of 6
pregnant mice were assigned as a control group. The second group consisted of 12 pregnant mice were exposed to
mobile phone radiation for 60 minutes daily and the third group consisted of 12 pregnant mice were exposed to
mobile phone radiation for 120 minutes daily starting from the zero day of gestation till the day of scarification. The
embryos of mice; were obtained at different period of gestation (At 16th day I.U.L., 18th day I.U.L.,and One day old
postnatal period).
Results Histological examination and immunohistochemical evaluation for CD34 expression were done for all animals
including control group showed that mobile phone (EMF radiation) with 900 MHz in short exposed period (one hour)
can stimulate tooth germ cells as it was shown,an early appearance of tooth germ in cap stage at 16th day I.U.L and
positive expression of CD34 marker on dental tissue.
Conclusion In this study we investigated an important point that the effects of mobile phones concerned on
mesenchymal germ cell rather than ectodermal germ cell which represented by positive reaction of CD34 on
mesenchymal cell of dental sac ,bone and cartilage. Increment in time exposure to EMF radiation emitted from
mobile phone for 2 hours duration showed retardation in tooth development with obvious reduction in size of the
mice.
Key words: Radiofrequency radiation, tooth germ, mobile phone. (J Bagh Coll Dentistry 2012;24(2):39-46).
INTRODUCTION
Mobile or cellular phones are now an integral part
of modern telecommunications.
In many countries, over half the population use
mobile phones and the market is growing rapidly.
At the end of 2009, there were an estimated 4.6
billion subscriptions globally. In some parts of the
world, mobile phones are the most reliable or the
only
phones
available.
Mobile
phones
communicate by transmitting radio waves through
a network of fixed antennas called base stations.
Radiofrequency waves are electromagnetic fields,
and unlike ionizing radiation such as X-rays or
gamma rays, can neither break chemical bonds
nor cause ionization in the human body.
Widespread concerns have been raised about the
possibility that exposure to the radiofrequency
(RF) fields from mobile telephones or their base
stations could affect people’s health Various
epidemiological and experimental studies have
been carried out and the results have shown to
have a close relation between biological effects
and Electromagnetic radiation (3). A large number
of studies have been performed over the last two
decades to assess whether mobile phones pose a
potential health risk. To date, no adverse health
effects have been established as being caused by
Radiofrequency fields are part of electromagnetic
spectrum. For the purpose of international
electromagnetic fields (EMF) project. Such fields
are defined as those within the frequency range
(10MHz-3000MHz). Common sources of
radiofrequency fields include: mobile telephones,
television broadcast, microwave ovens, medical
diathermy, radar, satellite links, microwave
communications and sun (1).
Mobile phone, some time called cellular phone
(GMS, Global system for mobile communication),
mobile telecommunication system has been
widely used all over the world. In others, mobile
phones are very popular because they allow
people to maintain continuous communication
without hampering freedom of movement (2). Cell
phones operate within the frequency band of 800
MHz, 900 MHz and 1800 MHz and the latest 3G
technology works between 1900 -2200 MHz Over
the past two decades, mobile telecommunication
system has been widely used all over the world.
(1) MSc. Student, Department of Diagnosis, College of Dentistry,
(2) Professor, Department of oral Diagnosis, College of Dentistry,
Oral Diagnosis
39
Vol. 24(2), 2012
components (lateral) &frontonasal prominence
(midline). The secondary palate can also be
divided in two anatomical parts: Anterior hard
palate &Posterior soft palate. The oral side of the
palate is covered with a squamous stratified
epithelium. The surface of the hard palate of most
mammalian species is further thrown into a series
of palatal ridges or rugae palatinae that are
transversal ridges. (10). Oral tissues are one of the
important parts of head/body that absorbs the
radiation emitted from mobile phones, there were
a lot of studies in that the effects of mobile phones
on head were investigated; but did not encounter
any histological study focused on the effects on
tooth development. Therefore, the goal of this
study is to investigate and to research an answer
to the question of have mobile phones effects on
palate and tooth germ development.
mobile phone use. Although there is a vast body
of material on the biological effects of
radiofrequency fields, current risk assessment is
still limited. There are several hypotheses and
results of biological effects such as thermal
effects, genetic and carcinogenetic effects and
cancers related investigations. The use of mobile
phones operating in the 900MHz frequency band
is very widespread and ever increasing (4). Tissue
heating is the principal mechanism of interaction
between radiofrequency energy and the human
body. At the frequencies used by mobile phones,
most of the energy is absorbed by the skin and
other superficial tissues, resulting in negligible
temperature rise in the brain or any other organs
of the body. A number of studies have
investigated the effects of radiofrequency fields
on brain electrical activity, cognitive function,
sleep, heart rate and blood pressure in volunteers.
To date, research does not suggest any consistent
evidence of adverse health effects from exposure
to radiofrequency fields at levels below those that
cause tissue heating. Further, research has not
been able to provide support for a causal
relationship between exposure to electromagnetic
fields
and
self-reported
symptoms,
or
“electromagnetic hypersensitivity” (5). Concern
has been expressed for number of years that
exposure to radiofrequency (RF) fields emanating
from mobile phones and radar and television
transmitters may increase the incidence of cancer
in humans (6). Epidemiological studies have not
indicated an increased cancer risk, but the
methodology and exposure assessment are
generally considered to have been suboptimal.
Several
reports
have
indicated
that
electromagnetic fields (EMF) enhance free radical
activity in cells. Free radicals kill cells by
damaging macromolecules, such as DNA, protein
and membrane (7).
Tooth development or odontogenesis is the
complex process by which teeth form from
embryonic cells, grow, and erupt into the mouth.
Although many diverse species have teeth, nonhuman tooth development is largely the same as
in humans. The tooth bud (sometimes called the
tooth germ) is an aggregation of cells that
eventually forms a tooth. These cells are derived
from the ectoderm of the first branchial arch and
the ectomesenchyme of the neural crest. The tooth
bud is organized into three parts: the enamel
organ, the dental papilla and the dental follicle (8).
The palate has two key stages of development
during embryonic (primary) and an early fetal
(secondary) involving the fusion of structures and
a key epithelial to mesenchymal transition (9). The
primary palate is formed by two parts: maxillary
Oral Diagnosis
Handsets of global system for communication
(GSM) mobile phone of the same brand and
model were used (Nokia 1100). Thirty pregnant
Bulb-c Albeno Swiss female mouse (2-3 months
of age, 100-125 gm of weight), were obtained
from the animal house of the national center for
drugs control and research, used in the present
experiment. The pregnant female was separated
from male in a different special Plexiglas cages
surrounded by the edges of the aluminum (Width
15 cm and height 10 cm); food pellets, bedding
and environmental conditions (temperature,
humidity and ventilation) were equal among all
animals. Those mice were divided into three
groups. The first group consisted of 6 pregnant
mice were assigned as a control group, nothing
applied to mice in this group and they completed
their life cycle in the cage during the study period.
The second group consisted of 12 pregnant mice
were exposed to mobile phone radiation for 60
minutes daily and the third group consisted of 12
pregnant mice were exposed to mobile phone
radiation for 120 minutes daily starting from the
zero day of gestation till the last day of
scarification .The embryos of mice; were obtained
at different period of gestation (At 16th day I.U.L.,
18th day I.U.L., and One day old postnatal period).
Histological preparation:
Sagittal sections through the head of the embryos
were separated from the body and preserved in
10% buffed formalin for 72 hours for histological
examination. The specimens were washed well in
running water, then dehydrated through graded
series of alcohols (50, 60, and 70 up to absolute
alcohol then xyline), cleared and embedded in
paraffin wax. Serial sections of specimens were
put at 5 microns by Reichert –Jung Microtome,
40
Vol. 24(2), 2012
and stained with Hematoxylin and eosin .All
sections were examined under light microscope.
Immunohistochemistry:
This study was performed on all formaline fixed
paraffin embedded blocks for all control and
experimental groups of different coating materials
and
techniques
using
CD34
with
Imunohistochemistry Detection Kit, HRP, Mouse
primaries (mouse tissue), BioAssayTM.
Figure 4: distribution of CD34 marker in the
progenitor cell and blood vessel (arrow) in
primitive mouth cavity.AEC stain X100
RESULTS
B-Experimental group 1:
Histological feature for upper and lower jaw
showed tooth germ cap to bell stage .Complete
fusion of secondary palate but still nasal septum
not fused with it, and tongue is high in position
filled the oronasal space. Lower tooth germ
illustrate stage (cap to bell) in development and
showed enamel organ with 4 layers inner enamel
epithelia ,outer enamel epithelia ,stellate reticulum
,stratum intermedium ,dental papilla, and dental
sac (Figure 5). Positive expression of CD34 was
illustrated in dental sac, in mesenchymal cell
while negative expression was reported in enamel
organ cell (Figure 6).
Clinical findings
A- In the present study the pregnant mice which
were exposed to EMF radiation of mobile phone
for a period of 2 hours, showed a retardation in
delivery time as for control group, pregnant mice
deliver embryo at 20-21 days of gestation period,
while experimental group which were exposed for
2 hours showed to be delivered in 28-30 days.
B-Clinical observation also illustrates different in
the size of the embryos .Control group and
experimental group one showed to be
approximately the same, their size range from
(14-16 mm3) in 18th day, while experimental
group two records (6-8mm3).One day old mice for
control and experimental group one, their size
range from (40-50 mm3), while for experimental
group two (30-35 mm3).
Histological and immunohistological findings
At 16th day I.U.L.
A-Control group:
Histological sections of the embryo head showed
upper tooth germ to be in bud stage represented
basal cell and central polyhedral cells (figure 3).
CD34 expression was detected in the progenitor
cell in primitive mouth cavity of the mice (Figure
4).
Figure 5: lower tooth germ at cap to bell
stage.H&EX200
Figure 6: positive reaction of CD34 in dental
sac (DS).AEC stain X200
C-Experimental group2:
A histological finding recorded a primitive mouth
cavity thickening in oral epithelia, underneath it
ectomesen-chymal tissue. Fig (7).Negative
expression of CD34 marker detected on cells of
oral epithelia and ectomesenchymal cells. (Figure
8).
Figure 3: upper tooth germ in bud stage
showed: basal cell (BC), central cell
polyhedral in shape (arrow), dental lamina
(DL).H&EX200
Oral Diagnosis
41
Vol. 24(2), 2012
Histological findings illustrate tooth germ at
advance bell stage with apposition of dentin.
Numerous blood vessels detected in the dental
pulp. Figure(11). Positive expression of CD34
was localized in dental papilla and dental sac and
in area of cell bone formation, while negative
AEC stain detected in enamel organ (Figure 12).
Figure 7: primitive mouth cavity of embryo
mouse 16th day intrauterine .H&E X200.
Figure 11: tooth germ showed odontoblast
(OD), dentin (D) and preameloblast
(PAB).H&EX200
Figure 8: Negative immunohistochemical
expression for CD34 on cells of oral
epithelium (OEP), and ectomesenchymal cell
(EMC).AEC X400
At 18th day I.U.L
A-Control group:
Histological section showed tooth germ at bell
stage for the lower jaw and tooth germ in cap
stage for the upper. Differentiation of dental
papilla to odontoblast cell can be detected but
with no feature of apposition of dentin (Figure 9).
Immunohistochemical reaction for localization of
CD34 in tooth germ shows moderate positive
reaction in dental sac and weak position in dental
papilla (Figure 10).
Figure 12: positive reaction for CD34
localized in dental pulp (DP) and in dental
sac (DS) around.AECX200
C-Experimental group 2:
This group illustrated tooth germ in bud stage in
upper jaw and disturbed and displacement in cells
of basal layer and central layer. While lower tooth
germ showed tooth development in cap stage also
displacement and disturbances in the cell micro
architecture were reported in figures 13. Negative
expression of CD34 was illustrated in all dental
layers of tooth germ except demarked line of
basement membrane showed positive stain
(Figure 14).
Figure 9: upper tooth germ in cap to bell
stage showed dental papilla (DP), inner
enamel epithelia (IEE), and dental lamina
(DL).H&E X100
Figure 13: Cross section in primitive mouth
showed dental lamina (DL), enamel organ
(EO), sign of displacement
(arrow).H&EX200
Figure 10: Immunohistochemical reaction
for localization of CD34 in tooth germ
showed positive reaction in dental sac area
(arrow),and weak positive reaction in dental
papilla(DP).AEC X200
Oral Diagnosis
42
Vol. 24(2), 2012
Figure 14: color demarked basement
membrane(arrow).AEC stain X400
Figure 17: tooth germ .Showed odontoblast
(OD), dentin (D), enamel (E) and ameloblast
(AB).H&EX400
At one day old (postnatal life)
A-Control group:
Histological examination for all sections
illustrated upper tooth germ at early bell stage and
lower tooth germ at advance bell stage (Figure
15). Immunohistochemical view for the tooth
germ illustrated negative reaction for CD34 in
enamel organ and positive reaction in dental sac
and endothelial cell of arteriol (Figures 16 A &B).
Figure 18: positive reaction for CD34 in
Dental sac (DS), blood vessels showed strong
positive reaction stain (arrow) ,upper limit of
the figure showed negative stain (blue)for
enamel organ(EO).AEC stain X400
Figure 15: tooth germs upper one in early
bell stage(EBS),lower in advance bell stage
(ABS), tongue (T) at the side.H&EX100
C-Experimental group 2:
Histological findings illustrateed tooth germ at
bell stage (Figure 19).Tooth germ illustrated
negative expression for CD34 in all dental layers
except basement membrane and in dental sac area
showed weak positive of AEC stain (Figure 20).
A
B
Figure 16: A :Negative reaction for CD34 in
enamel organ (EO), positive reaction in
dental sac (DS) and bone formation area
(B).AEC stain X200 B: View for dental sac
area showed blood vessels arteriol,
endothelial cell (arrow) stain positive for
CD34 marker ..AEC stain X200
A
B
Figure 19: A: tooth germ at bell stage in
neonatal mouse Showed odontoblast (OD),
preameloblast(PAB),stellate reticulum(SR)
,and dental papilla(DP).H&EX200. B:
positive reaction of CD34, illustrated in
basement membrane (arrow) separates
odontoblast (OD) from ameloblast (AB).
AEC stain X200
Histological examination illustrateed apposition
of dental hard tissue enamel and dentin with their
formative cell ameloblast and odontoblast (Figure
17). Tooth germ showed positive stain high
lightened on dental sac cell and blood vessels,
while enamel organ illustrated negative stain
(Figure 18).
Oral Diagnosis
DISCUSSION
Radiofrequency waves emitting from cellular
phones and base stations has emerged as a fact
which affect increasing number of people by the
time. As cellular phone usage gets more
widespread, electromagnetic radiation has become
an important health problem, which was also
reported by the previous studies suggesting the
harmful effects of radiofrequency waves on
human health (11-14). So far, there has been a
43
Vol. 24(2), 2012
related with changes in Mg and Zn amounts.
However, these findings suggested the possibility
of GSM-Modulated 900 MHz radiation to play an
important etiological role in mineralization
process. Kaya et al 2008 studied the effects of
radiofrequency radiation by 900 MHz mobile
phone on periodontal tissues and teeth used
experimental rat group exposed to mobile phone
radiation for 2 h/day, 7 days/week, and 10
months. At the end of the experiment, the
histopathological evaluation showed abnormal
changes like vasodilatation and focal bleeding
area were determined in periodontal ligament,
alveolar bone , gingival and pulpa among some
individuals.
It is well known that embryonic tissue be
immature regarding to tooth germ layer be very
sensitive and susceptible to injury especially to
chemical material like drug and when exposed to
radiation in which its effects depend on its
duration and frequency. The most possible effects
of RF fields on cell receptors alter the protein
conformation by Changes in binding to cell
receptor proteins. Chiabrera et al in 2000 found
that significant changes in the probability of
ligand binding could be produced by the
modulation of the well shape by RF electric fields
below guideline values. Therefore, in these results
it seems that exposed for 2 hours daily be harmful
to the progenitor cells, while 1 hour seems to
enhance and act as stimulator to the stem cells.
Moreover the pathologies such as oedema,
interstitial hemorrhagia, collagen decomposition,
dearrangement of specialized cells such as
odontoblast ameloblast ,osteoblast were not
detected in dental tissue of the embryo mice of the
present study exposed for EMF of both
duration(60,120 min.) These results disagreed
with results of Kaya et al 2011, who used low
frequency magnetic field on pulp tissue of rats.
They found it affected odontoblast and fibroblast
cells and they attributed to un accurate intensity of
EMF that be used on the dental tissue of their
experiment.
The present result illustrated an early deposition
of dental hard tissue in experimental group
exposed to EMF for one hour at 18th day of
gestation and at one day of neonatal life in
comparison to control and the study suggested
that exposure for short duration activate
specialized dental cells (odontoblast and
ameloblast) to deposit organic matrix of enamel
and dentin, and may play a role in mineralization
and maturation processes. For the experimental
group two at the same above periods, it has versus
action, it retards development and disturbs the
differentiation of specialized dental cells either by
controversy whether EMF has a negative effect on
health or not. Any embryo toxicity of EMF in
pregnant mothers raises public apprehension.
Concerns about potential susceptibility of embryo,
fetal, newborn and the juvenile to EMF are
comprehensible due to the immaturity of all
organs in their developing stages. A large number
of in vivo studies have been carried out in
mammals reported only slightly effects on fetus
(15, 16)
.
The present results showed an early tooth
development for embryo aged 16th day
intrauterine life when its mother was exposed for
one hour to radiation, upper and lower teeth
showed tooth germ at cap stage with well
developed, fused palate, well developed ridges. In
comparison to control, which illustrated tooth
germ in bud stage? On the other hand exposed for
two hours duration to radiation affected the tooth
development in versus way, as the results showed
retardation in development of teeth and palate.
Tooth germ recorded to be missed in 16th day of
gestation and hardly oral ectodermic thickness
was detected. These results could be explained on
the followings:
Electromagnetic waves may interact with
biological tissues through either thermal or
nonthermal mechanisms. The components of the
biological system, like those of any other system,
are constantly subjected to the random fluctuating
electric and magnetic fields associated with the
random motion of charges known as Brownian
motion or thermal noise. As electromagnetic
fields with high frequency can be hazardous in
terms of thermal changes, long time exposure to
low frequency electromagnetic waves can lead to
some unexpected biochemical changes in the
body (17). As the frequency interval of analogue
phones is between 800 and 900 MHz, digital
phones work between 1850 and 1990 MHz
frequencies (18). All review of literatures studied
mostly on body tissues. But did not find any
studies regarding the effects of EMF on tooth
development, only few of the studies conducted
by Adiguzel et al in 2008 used experimental rat
group exposed to GSM-Modulated 900 MHz
radiofrequency radiation for 2 hours per day
during ten months. At the end of the exposure
period, the contents of some elements as Ca, Mg,
Zn, and P were measured in the oral tissue. The
measurements were performed by Atomic
Absorption Spectrophotometry (AAS). However,
phosphorus content of teeth was measured by
ultraviolet spectrophotometer (UVS). The results
showed positive change evidence in rat’s teeth,
and it supports the hypothesis that GSMModulated 900 MHz radiofrequency radiation is
Oral Diagnosis
44
Vol. 24(2), 2012
one hour act as stimulator and activates cell
proliferation and differentiation. Dental papillae
showed weak positive in expression for CD34 and
that related to its localized ability to form multispecialized tissue as in dental sac, it only formed
pulp although it contains blood vessels, nerves,
progenitor mesenchymal cells but not extended
like dental sac. The negative immunoreactions of
CD34 marker of enamel organ cells attributed to
its ectodermal embryonic origin.For experimental
group exposed for two hours to EMF, it showed
only positive reaction in basement membrane, as a
basement membrane is an acellular structure,
made up of neutral polysaccarides, fibronectin,
laminin, type IVcollagen and as CD34 is a 110kDa transmembrane glycoprotein present on stem
cells. Therefore its positive immunoreaction may
be related to cross reaction and close similarity
with chemical components of antigens. So its
expression is not clear and it needs more
investigations. Nourbakhsh et al 2011 studied in
vitro the Stem cells from human exfoliated
deciduous teeth (SHED) which are highly
proliferative, clonogenic and multipotent stem
cells with a neural crest cell origin. Expressed
antigens CD146, CD45, CD90, CD106 and
CD166, but not the hematopoietic and stem cell
markers, CD34 and CD31was detected. These
results were disagreement with our findings.
Several reviews on the issue of possible adverse
health effects of mobile phones have been
published (25). The fact that some environmental
factors like GSM-Modulated 900 MHz
radiofrequency radiation fields may have some
harmful effects continues to arouse more interest
especially in last two decades. Some literature has
been reported that environmental effects such as
GSM-Modulated 900 MHz radiofrequency
radiation may affect health status in accordance
with the altered physiological conditions (26).
For this reason, further studies are needed to
reveal the effects of environmental factors on oral
tissues and tooth development more clearly.
affected its functions in formation of hard tissues
of embryo or due to hormonal changes of
pregnant mother. Therefore; these results, which
have been obtained from study on animals, should
be further investigated and mainly for
biochemical mineral analysis of dental tissue. At
the same time we didn’t encounter any
histopathologic studies focused on embryo
development concern with tooth germ and
palatine growth. Therefore; this study may
consider the first one in this field.
CD34 is a well-known marker of progenitor cells
of blood vessels, stromal tissues, bone cell and
mesenchymal cells. Thus, CD34-positive cells
have recently been used clinically in the field of
vascular and orthopedic biotechnology because of
their capacity to assist regeneration of injured
tissues. However, as known, the in situ detection
of CD34positive cells has not yet been described
in the fetus, with the exception of a few organs,
Abe et al 2011 study expression of CD34 in
human mesenchymal tissue of fetuses (9-15
weeks of gestation). They detected CD34-positive
structures as a vessel-like appearance and were
regularly arrayed in the viscera, nerves and lymph
nodes, in the body wall and extremities.
In the present study, immunohistochemistry for
CD34 expression in embryonic tissue in different
periods of gestation of a mice (16th, 18th and one
day postnatal period) was used to include all
primitive stem cells suspected to be involved in
the formation of the face including teeth, jaws,
palate, tongue and other related structures and
because it is the first research till the time of
prepared thesis studied in vivo dental cell
immunoreactions with CD34 markers. The
present study illustrateed the followings: strong
positive expression of CD34 on cells of dental
sac, weak positive on cells of dental papilla and
negative immunoreactions for enamel organ cells
to CD34, in all studied periods and concern to
experimental group of one hour duration. These
results could be explained on the facts that dental
sac is an ectomesenchymal tissue derived from
neural crest cells, the fourth germ layer that form
the periodontal tissue and alveolar bone which
they are rich in the progenitor of hematopoietic
cells, endothelial cell of capillaries, followed by
arteries, veins, arterioles, and venules, dendritic
interstitial cells around vessels, nerves, muscle
and bone cells. And even the related structure
such as the nasal cartilage cells expressed positive
CD34 marker indicated for the potency of the
cells to proliferate and differentiate into multiple
mesodermal tissues such as bone, cartilage,
muscle, tendon …etc. This result supported the
histological findings in that exposure to EMF for
Oral Diagnosis
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46
Vol. 24(2), 2012
Chronological ِage estimation
Chronological ِage estimation in adolescent and young
adult subjects in relation to mandibular third molar
development using digital panoramic image
Jaafar J. Attar, B.D.S. (1)
Jamal Ali AL-Taei, B.D.S., M.Sc. (2)
ABSTRACT
Background: Predicting chronological age in adolescents and young adults can be crucial in Medico legal contexts
and the third molar is the only developing tooth during this period that used to determine chronological age.
The purpose of this study was to estimate the chronological age based on the stages of mandibular third-molar
development following the eight stages (A–H) method of Demirjian et al
Materials and methods: The sample consisted of 436 Iraqi adolescents and young adults subjects have been chosen
with known chronologic age (range, 14–24 years) and sex (162 males and 274 female), digital panoramic
radiograph had been taken for each examined subject, Demirjian’s grading has been used to assess third molar
development
Results: Statistically significant differences (P _ 0.05) in third-molar development between males and females were
revealed regarding the development stages D,E and F. Third-molar genesis was attained earlier in males than in
females. Statistical analysis showed a strong correlation between age and third-molar development for males (r 2 _
0.91) and for females (r 2 _ 0.87).
Conclusion: It was concluded that the use of mandibular third molar development stages using Demirjian method
can be considered as good valuable chronological age indicators in adolescents and young adults
Keywords: Third molar; Chronological age; Age estimation. (J Bagh Coll Dentistry 2012;24(2):47-50).
Therefore developing 3rd molar is the only
reliable biological dental indicators variable and
readily assessable from dental radiographs during
adolescence and the transitional period to
adulthood, Indeed a great variation in position,
morphology, and time of formation(6,7,8) .Up to
now several studies have been undertaken in
different populations these studies show that 3rd
molar development varies slightly between
different populations, making population-specific
studies necessary. Recently, for different ethnic
groups, numerous reports have been published on
the evaluation of third-molar development (9, 10).
Panoramic radiography is a radiological
technique for producing a single image of the
facial structures that include both the maxillary
and mandibular dental arches and their supporting
structures. Digital radiography is considered to be
a great enhancement to the diagnostic radiography
due to its radiation dose reduction, improved
image properties, improved storage and
transportability of the
Image and reduce equipment and time needed to
produce a superior image (11).
The aim of this study was to estimate
chronological age and gender in adolescent and
young adult subjects based on stages of
mandibular third molar according to Demirjian
method using digital panoramic image.
INTRODUCTION
In the past decade the number of unidentified
cadavers and human remains as well as the
number of remains lacking age documentation
and therefore requiring age determination has
increased. This requires age calculation, not only
for differentiating the juvenile from the adult
status in criminal law cases, but especially when
determining the age of a crime victim and also for
estimating chronologic age in relation to school
attendance, social benefits, employment, and
marriage (1,2).
Method of chronological age estimation in
adolescents and young adults may be including
radiographical examination of the hand and wrist,
the medial clavicular epiphyseal cartilage, and
finally 3rd molar development observations (3, 4, 5).
But compared to bone development, 3rd molar
development are less affected by variation in
endocrine and nutritional status, and in hand and
wrist development it is completed around the age
of 18 while 3rd molar development continues until
the early twenties when the development of
almost permanent teeth may be completed, and
regressive changes in teeth with increasing age
may not yet appear at that age.
Samples selection:
In this cross-sectional study, dental panoramic
image of 450 Iraqi subjects with known
chronologic age and sex were selected.
(1) M.Sc. Student, oral and maxillofacial radiology, oral diagnosis
Department, College of Dentistry, Baghdad University.
(2) Assistant Professor, oral diagnosis Department, College of
Dentistry, Baghdad University.
Oral Diagnosis
47
Selection criteria included the following:
• Adolescent and young adult Subjects;
• Well nourished and free of any known
serious illness;
• Normal growth and development and dental
conditions, for example, no impactions,
congenital absence, or transposition of teeth.
Exclusion criteria excluded the following:
• Image deformity affecting third molars; and
• Panoramic image showing obvious dental
pathology.
Fourteen films were excluded for poor
radiographic quality, and for agenesis of the third
molars. The final sample consisted of 436
Panoramic image from Iraqi individuals of known
chronologic age and sex. Mean age range of the
436 patients for both genders was (14- 24 years).
All assessments were performed by digital
panoramic image in computer to ensure contrast
enhancement of the tooth images.
Examination and classification covered the
development phase of the left mandibular molar
third and, when not present, the Contra lateral
molar was considered.
Tooth calcification was rated according to the
method described by Demirjian et al 12 in which
one of eight stages of calcification, A to H, was
assigned to the third-molar tooth (Figure 1).
All statistical analyses were performed using
SPSS version 15.0. (Statistical Package for Social
Sciences)
To test the reproducibility of the assessments of
dental development stage, two investigators
reevaluated randomly selected panoramic
radiographs from 10% of the same male and
female subjects after the first evaluation. Interand intra observer agreements were determined
using the Binominal–test (non-parametric test)
RESULTS
Repeated scorings of a subsample of 40
radiographs indicated no significant intra- or inter
observer differences (P_0.05). Intra observer
consistency was rated at 98%, whereas inter
observer agreement was 95%.
The third-molar formation process was examined
in both sexes, and the mean ages and standard
deviations for the Demirjian stages are described
in (Table 1).
Data for Demirjian stages A, B and C was omitted
from the study because no teeth in stages A and B
were noted and less than 1% was noted in stage C
for the present study
In both male and female sample groups there is
strong positive relation ship between the dental
development stage of mandibular third molar and
chronological age (p<0.001, for both sexes)
Statistically significant differences (P _ 0.05)
were revealed in third-molar development
between males and females regarding the
calcification stage D and stage E. These
differences indicated that third-molar genesis
attained the Demirjian formation stages earlier in
males than in females.
Table 1: Descriptive statistic of both genders
Figure1: panoramic image shows third
molar development.
Sex
Stages
D
E
F
G
H
Sex
D
E
F
G
H
The first four stages (A–D) show crown formation
from the beginning of cusp calcification to
completed crown, and the second four (E– H) root
formations from initial radicular bifurcation to
apical closing.
Descriptive statistics were obtained by
calculating the means, standard deviations,
and range of the chronologic ages for the eight
stages of dental development.
Statistical analyses were performed using the
Student's t-test between sex and age. ANOVA test
was used to test the statistical significance of
difference in mean between developmental stages
groups of mandibular molar.Pearson's correlation
coefficient to test statistical significance, direction
and strength of linear correlation between 2
quantitative normally variables.
Oral Diagnosis
Vol. 24(2), 2012
Male
Mean
SD
14.40 0.627
15.79 1.503
17.85 1.405
19.00 1.275
21.32 1.561
Female
15.09 1.460
16.66 1.250
18.07 1.557
19.46 1.444
21.36 1.314
DISCUSSION
Chronologic age estimation by tooth development
has been used over a long period. Tooth
development is an accurate measure of
chronologic age that seems to be independent of
48
Vol. 24(2), 2012
However, other researchers have demonstrated
similar mean age values and distributions for
sexes (10, 24,25).
The stage of development of the third molar has a
practically linear relation to the age of the
subjects, whether male or female. Statistical
analysis shows a stronger correlation for male (r
2_0 .91) than for female (r 2 _0 .87) subjects.
These results also agree with studies on other
populations 9.
exogenic factors such as malnutrition or disease
(13-15).
The third-molar calcification stage is one of the
few tools that can be used to assess age when
development is nearing completion during
adolescence when the third molar is the only
remaining variable dental indicator (16).
The differences between populations, the
different methodology, and the dissimilarity
among
observers
are
other
important
shortcomings. In the present study, to overcome
some of these shortcomings, all selected subjects
were evaluated by two well trained observers
using eight stages according to the method of
Demirjian et al.12 a range of different
classifications for evaluating tooth mineralization
is available.
In the past, different classifications were
presented by Gleiser and Hunt, 17 Moorrees et al,
18
Kohler et al.19 and Kullman et al, 20 However,
some of these classifications identify a large
number of stages that are hard to delimit from
each other. Demirjian et al12 presented a
classification distinguishing four stages of crown
development (stages A–D) and four stages of root
development (stages E–H). The system avoids
any numeric identification of stages so as not to
suggest that the different stages represent
processes of the same duration. The stages
proposed by Demirjian et al12 are defined by
changes of shape, independent of speculative
estimations of length.
Dhanjal et al 21 investigated the reproducibility of
different radiographic stage assessment of third
molars and concluded that the method of stage
assessment of third molars developed by
Demirjian et al 12 performed best not only for
intra- and inter examiner agreement, but also for
the correlation between estimated and true age.
Therefore, this classification seemed to be the
most appropriate for our study.
In the present study examined the mean ages of
each stage for male and female patients
statistically significant differences (P_0.05) in
third-molar development between male and
female subjects were revealed regarding
calcification stages D and E.
These significant differences indicated that thirdmolar genesis in males attained these Demirjian
formation stages 6 to 8 months earlier than in
females.
This observation was consistent with previous
studies, which report that the mean age at some of
the development stages was lower for males than
for females in the following populations:
Hispanics, 22; Belgian whites, 23 Swedes, 20 or
people of Spanish origin9.
Oral Diagnosis
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20. Kullman L. Accuracy of two dental and one skeletal
age estimation method in Swedish adolescents.
Forensic Sci Int 1995; 75: 225–36.
21. Dhanjal KS, Bhardwaj MK, Liversidge HM.
Reproducibility of radiographic stage assessment of
third-molars. Forensic Sci Int 2006; 159:74–7.
22. Solari AC, Abramovitch K. The accuracy and
precision of third-molar development as an indicator
of chronological age in Hispanics. J Forensic Sci
2002; 47: 531–5.
23. Thorson J, Ha¨gg U. The accuracy and precision of the
third mandibular molar as an indicator of
chronological age. Swed Dent J 1991; 15:15–22.
24. Willershausen B, Loffler N, Schulze R. Analysis of
1202 orthopantograms to evaluate the potential of
forensic age determination based on third-molar
developmental stages. Eur J Med Res 2001; 28:377–
84.
25. Arany S, Iino M, Yoshioka N. Radiographic survey of
thirdmolar development in relation to chronological
age among Japanese juveniles. J Forensic Sci 2004;
49: 534–8.
.
Oral Diagnosis
50
Vol. 24(2), 2012
Diagnosis of the angular
Diagnosis of the angular hyperkeratotic lesions and the
incidence of the etiologic factors
Jamal N. Ahmed, B.D.S., M.S., Ph.D. (1)
ABSTRACT
Background: Hyperkeratotic lesions located at the angle of the mouth are common among patients attending
dental clinics. Most dentists are unaware of it since the patients are not seeking care. The purpose of the present
study was to find out the incidence of the diagnosed lesions and their relation with the etiologic or initiating factors.
Materials and methods: A total of (112) patient’s (62) males and (50) females having angular hyperkeratotic lesions
were selected from patients attending the dental clinic in Baghdad dental school. The clinical diagnosis and the
progression of the lesions were conducted by using 1% toluidine blue stain to confirm the premalignant potentials
and to delineate the margins of the lesion for the biopsy. Microscopic examinations were done for the confirmation
of the final diagnosis. The associating factors like smoking, alcohol, dental irritation, prosthesis, systemic diseases, and
angular chelitis were recorded in the patient information sheet for the result analysis.
Results: The results showed that the benign hyperkeratotic lesions were the higher (36.6%) in distribution, while the
malignant neoplasms were the 2nd (25.89%) in frequency, followed by premalignant lesions (21.42%), lichen planus
(12.5%), and benign growth (3.57%). Smoking habit was the most common associating factor (54.6%), followed by
angular chelitis (48.2%), dental irritation (43.7%), systemic diseases (35.7%), dental prosthesis (28.5%) and alcohol
consumption 0.05%.
Conclusion: The hyperkeratotic lesions occurred in a wide range of ages. The benign lesions were the most common
types. However a significant number of cases had premalignant and malignant changes. The presence of the
associating factors acting alone or in combination were having a role in the existence of the lesions. The
premalignant potentials increase with age and the chronicity of the associating factors such as smoking and angular
chelitis were having a significant role in existence of the lesions. In addition, the results showed that the angular
hyperkeratotic lesions existed in the majority of the patients were bilateral in behavior.
Key words: Angular, Hyperkeratotic, Etiologic factors. (J Bagh Coll Dentistry 2012;24(2):51-55).
INTRODUCTION
The investigators confirmed the property of
toluidine blue discoloration to verify clinically
suspicious lesions as neoplastic to delineate
margins of premalignant and malignant growth
and to detect unnoticed or satellite tumors7. The
high sensitivity of the test appears to offer a
feasible diagnostic control and lesions that stain
with toluidine blue should be considered
carcinoma unless proven by biopsy.8-10
When clinical hyperkeratotic lesions are studied
microscopically they could be seen to embrace
various histologic changes that shows only
increase keratosis to invasive squamous cell
carcinoma. These differences cannot be identified
clinically so to establish a specific diagnosis the
lesion need to be examined microscopically.10,11
Differential diagnosis of white lesions is based on
location, history, and other physical findings. The
distribution of leukoplakia lesions is of diagnostic
value in the transmission to malignancy. The
tongue and the floor of the mouth are the most
common locations of malignant lesions; however
the cheek and lips are the common sites of
leukoplakia with dyskeratosis.12
A significant number of patients attending the oral
diagnosis clinic seeking dental treatment are
having white lesions, and may be unaware of it
since it is asymptomatic. In practice, the angle of
the mouth is exposed to fungal infections,
Hyperkeratotic lesions “leukoplakias” are
commonly seen on the oral mucous membrane.
Fortunately, most are benign and justify little
clinical concern once a definitive diagnosis is
made1. However, a small proportion of these
lesions represent dysplastic, early malignant or
neoplastic lesions of the surface epithelium.
Idiopathic leukoplakia is reserved for white
lesions suspected of cancerous or precancerous
character when direct cause or specific benign
condition explains the abnormal appearance.2, 3 A
variety of local irritations such as tobacco
products, hot and spicy foods, occlusal trauma,
sharp prosthesis, presence of candida albicans,
acting alone or in combination produce keratotic
lesions in certain individuals.1,4 Squamous cell
neoplasms of the oral cavity and leukoplakia
share many of the same etiologic factors.5
Diagnosis of the dysplastic lesion and early
squamous cell carcinoma could not be determined
based on the clinical findings only.
Toluidine blue stain is a reliable clinical method
and proposed as a vital stain to disclose dysplasia
and carcinoma in situ. The stain was used for the
detection of premalignant and malignant lesions
of the oral cavity.6
(1)
Assistant professor, department of oral diagnosis. College of
Dentistry, University of Baghdad.
Oral Diagnosis
51
Vol. 24(2), 2012
lesions (36.6%). While the malignant neoplasms
were the 2nd in frequency (25.89%) having
mainly sqamous cell carcinoma (19.64%) which
was highest than verrucous carcinoma (3.57%)
and ca in situ (2.67%). Among the premalignant
lesions which represent (21.42%) of the angular
hyperkeratotic lesions, epithelial dysplasia had the
highest distribution (11.6%), followed by candidal
leukoplakia (7.14%) and verrucous leukoplakia
(2.6%).
Benign growths which were mostly of viral origin
represent the least in distribution (3.57%),
including papillpma, and verrucous vulgaris.
Lichen planus (dermatosis) was included when
the diagnosis was suspicious and should be
located at the angle of the mouth (fig.4). It was
not considered whether they were erosive and
non-erosive and the result was (12.5%) of the
total cases.
Table 2 summarized the relation between the
lesions in the males and females with the
associating factors. The table was descriptive
rather than analytic, because number of cases of
the specified lesions was small, so that the
associating factors did not give a conclusion about
the effect of these factors on the specified lesion.
However, the total numbers showed smoking
habit (54.46%) was the highest in frequency.
Angular chelitis was also high (48.2%) because
the number of patients having premalignant and
malignant lesions showed significant number of
lesions associated with candidiasis. The effect of
dental irritation and cheek biting (43.7%) and a
history of presence of removable or fixed
prosthesis (28.5%) showed a relation with benign
hyperkeratosis in particular.
Presence of systemic diseases (oral and skin
autoimmune diseases, diabetes, hypertension,
anemia, vitamin deficiency and drug allergy) as
an associating factor of the lesions was seen in
35%. Alcohol consumption, regardless of the
amount used, was the least 0.05% in frequency.
occlusal trauma, smoking irritations, and is the
common site of the lesion.
The purpose of this study was to find out the
incidence of the diagnosed hyperkeratotic lesions
that are existed at the angle of the mouth, in
addition to the frequency of the relation with the
etiologic or initiating factors.
A thorough clinical examination of the oral soft
tissue was conducted for patients attended the oral
diagnosis clinic, college of dentistry, university of
Baghdad in the period between 1997-2005.
Emphasis was done on angular hyperkeratotic
lesions. A total of 112 patients were selected for
this study. They were (62) males and (50) females
with age ranges between (11-90) years.
The information about systemic diseases, smoking
habits, presence of traumatic factors, and presence
or absence of angular chelitis were collected and
registered in the case sheet.
The clinical method of investigation was done by
applying toluidine blue stain protocol to the
mucosal lesion.7,10,13 The lesion was washed with
water for few seconds for the removal of debris
present, then rinsed with 1% acetic acid and
followed by swabbing with a piece of cotton
socked with 1% toluidine blue stain. After
application of the stain acetic acid was used again
for discoloration. The lesions that picked up the
royal blue stain were considered malignant
neoplasm (fig. 3). While the lesions that have
picked up few amount of the stain as dark spots
inside a white lesion considered precancerous
lesion (fig. 2). The entire positive and the
clinically suspicious negative reacted lesions were
biopsied and examined under the light microscope
for the final diagnosis. The presence of dysplastic
changes within the epithelium regardless of the
severity was considered premalignant. The
suspicious lesions were selected and stained with
PAS stain for the detection of candida albicans.
Presence of candidal hyphe within the lesions was
considered candidal leukoplakia.
The data were collected and analyzed for the final
results.
DISCUSSION
The clinical manifestations of various white
lesions are the same. However, the histologic
appearance
implicate
different
histologic
diagnosis varies in nature from benign to highly
malignant potentials. Squamous cell carcinoma is
the most common malignant disease of the oral
cavity and one of the few potentially fatal
conditions the dentist is likely to initially identify.
The site and distribution of the hyperkeratotic
lesions in the oral mucosa is considered an
important factor in the diagnosis and prognosis of
the disease.1,3,12 About 71% of the hyperkeratotic
lesions of the oral cavity are benign in nature.12
RESULTS
According to the clinical and histologic diagnosis,
the white lesions were classified into benign
lesions, premalignant lesions, benign growth,
malignant neoplasms, and lichen planus. Table 1
shows the general classification of the lesions and
the frequency distributions of the specific lesions
in their categories. Benign hyperkeratotic lesions
represent the most frequent among other angular
Oral Diagnosis
52
Vol. 24(2), 2012
published that Smoker keratosis was oftenly
benign and the development of dysplastic lesions
apparently require several decades of exposure
because leukoplakia is unusual among young
patients before 40 years and is more typical after
the fifth dacade.12 This agree with our results that
premalignant lesions are existed in an elderly ages
of the males and females.
Angular mucosa is commonly subjected to
various irritation factors and the angle of the
mouth is the common site exposed to trauma from
occlusion of the canine and premolars and
removable or fixed prosthesis. The general
condition of the oral mucous membrane as
influenced by both regional and systemic
disorders is important in enhancing effectiveness
of the locally active factors. Systemic diseases
such as nutritional deficiency, anemia, diabetes
mellitus, lichen planus, xerostomia, and
autoimmuine diseases...etc are associated with
atrophic changes in the oral mucous memberene
that predispose these patients to both leukoplakia
and oral carcinoma.19,20 In this study they were
commonly noticed associated with benign,
premalignant, and malignant lesion as well as
with lichen planus.
The presence of chronic infections at the angle of
the mouth due to candida albicans was seen
associated with different specific lesions and the
malignant lesions in particular. This was probably
more superimposing in nature than as initiative
factor. However, when hyperkeratosis at the angle
of the mouth associated with chronic irritation,
inflammation or infection due to angular chelitis,
and associating systemic diseases in adult and old
patients, biopsies were required to identify the
dysplastic changes by using tolidine blue and
microscopic examination.
Alcohol consumption was the least associating
factor noticed in this study, the reason may be
some patients deny this habit since socially and
religiously is unaccepted in this country.
A point worth mentioning during the clinical
examination, it was noticed that the majority of
cases included in this study showed the angular
hyperkeratotic lesions were distributed in a
bilateral behavior.
Angular benign hyperkeratotic lesions represent
the majority of the cases diagnosed in this study
but the percentage (36.6%) shows less if
compared with leukoplakias distributed in other
sites of the oral mucosa. Locations and
distributions of hyperkeratotic lesions in the oral
mucosa indicate reliability to malignant
transformation.11,14 The results showed neoplastic
lesions (carcinoma in situ, verrucous carcinoma,
and squamous cell carcinoma) are in the second
place of occurrence at the angle of the mouth
compared with other hyperkeratotic lesions at the
same site. It was found that leukoplakia with
dyskeratosis occurs in the buccal mucosa as a first
site in frequency compared with the other sites of
the oral mucosa.15 Our findings revealed (21.42%)
of the total hyperkeratotic lesions. Epithelial
dysplasia is the majority diagnosed followed by
candidal leukoplakia, and verrucous leukoplakia
respectively.
Lichen planus whether erosive and non-erosive
types were included when the location of the
lesion was present strictly at the angle of the
mouth. In some cases the plaque type was
confusing with planer type leukoplakia in the
clinical form, and the erosive types were similar
to dysplastic lesions in their form of mixed red
and white lesion (fig. 4).
Benign neoplastic growths were seen at the angle
of the mouth and diagnosed as papilloma and
verrucous vulgaris. They were viral in origin and
diagnosed clinically and histologically. Verrucous
vulgaris was seen in young patients and one of the
cases was an 11 year old child attended the clinic
having white verrucous lesion restricted at the
angle of the mouth (fig. 5). The lesion at the
beginning gave the clinical manifestation of a
premalignant or even a malignant lesion, but there
were papillomas located at the hands. The parent
refused to take a biopsy so that the diagnosis was
based on the associated lesions of the hand and, in
addition the regression of the lesion after
following up the case.
The existence of the angular hyperkeratotic
lesions in a wide range of age groups with no
significant difference in both sexes made them of
no diagnostic value in general. However, they
were useful in the diagnosis of the specified
lesions if correlated with the associated factors.
The most common etiologic factor implicated in
the development of oral epithelial dysplasia and
squamous cell carcinoma is smoking habit.
Buccal mucosa at the angle of the mouth is the
early site exposed to thermal irritation due to
smoking.17,18 Smoking habits were noticed in
significant percentage of the total lesions and
represent the higher associating factor. It has been
Oral Diagnosis
REFERENCES
1.
2.
3.
53
Norman KW, Paul WG. Differential diagnosis of oral
lesions: White lesions of the Oral Mucosa. 5th ed.
The C.V. Company; 1997. p. 96-126.
Bouqnot, JE, Gorlin, RJ. Leukoplakia, Lichen planus,
and other oral keratosis in 23,616 white Americans
over the age of 35 years. Oral Surg Oral Med Oral
Pathol 1986; 61:373-81.
Silverman SJ, Gorsky M, Lozada F. Oral leukoplakia
and malignant transformation: a follow-up study of
257 patients. Cancer 1984; 53:563-8.
Vol. 24(2), 2012
12. Coleman, GC, Nelson FN. Principles of oral
diagnosis; Differential diagnosis of white lesions.
Mosby yearbook. 1993:278-99.
13. Epstein JB, Güneri P. The adjunctive role of toluidine
blue in detection of oral premalignant and malignant
lesions. Curr Opin Otolaryngol Head Neck
Surg. 2009; 17(2):79-87.
14. Bhaskar SN. Synopsis of oral pathology: Surface
lesions of the oral mucosa: Sixth Ed., Published by
the C.V. Mosby Company 1981; 373-460.
15. Bouquot, JE. Reviewing oral leukoplakia: Clinical
concepts for the 1990’s. J Am Dent Assoc
1991;122:80.
16. Banoczy J, Csiba, A. Occurrence of epithelial
dysplasia in oral leukoplakia, Oral Surg 1976; 42:
766.
17. Berry HH, Landwerlen, JR. Cigarette smoker’s lip
lesion in psychiatric patients, J Am Dent Assoc 1973;
86: 675.
18. Salonen L, Axell, T, Helldin, L. Occurrence of oral
mucosal lesions, the influence of tobacco habits and
an estimate of treatment time in an adult Swedish
population. J Oral Pathol Med 1990;19:170.
19. Park KK, Brodell RT, Helms SE. Angular cheilitis,
part 2: nutritional, systemic, and drug-related causes
and treatment. Cutis 2011; 88(1): 27-32.
20. Burket LW. Burket’s Oral Medicine: Diagnosis and
treatment. 9th ed. JP Lippincott Company; 1994. p.86.
4.
Arendrof TM, Walker DM, Kingdom RJ, Roll J. New
Combe, RG, Tobacco smoking and denture wearing
in oral candidal leukoplakia. Br Dent J 1983; 155:
340-3.
5. Llewedyn J, Mitchell R. Smoking alcohol and oral
cancer in southeast Scotland: a 10 year experience,
Br J Oral Maxillofac Surg 1994: 32:146-8.
6. Epstein JB, Oakley C, Millner A, Emerton S, van der
Meij E, Le N. The utility of toluidine blue application
as a diagnostic aid in patients previously treated for
upper
oropharyngeal
carcinoma
Oral Surg Oral Med Oral Pathol Oral Radiol
Endod 1997; 83(5): 537-47
7. Miller RL, Simms BW, Gould AR. Toluidine blue
staining for detection of oral premalignant lesions
and carcinomas. J Oral Pathol 1988;17:73-8.
8. Rosenberg D, Cretin S. Use of meta-analysis to
evaluate tolonium chloride in oral cancer screening.
Oral Surg Oral Med Oral Pathol 1989; 67: 621-7.
9. Mashberg A. Revaluation of toluidine blue
application as a diagnostic adjunct in the detection of
asymptomatic
oral
squamous
carcinoma.
Cancer1980; 46: 758-63.
10. Upadhyay J, Rao NN, Upadhyay RB, Agarwal P.
Reliability of toluidine blue vital staining in detection
of potentially malignant oral lesions - time to
reconsider. Asian Pac J Cancer Prev 2011; 12(7):
1757-60.
11. Waldron CA, Shafer WG. Leukoplakia revisited: a
clinicopathologic study of 3,256 oral leukoplakias,
Cancer 1975; 36:1386.
Oral Diagnosis
54
Vol. 24(2), 2012
Table 1: The classification of the diagnoses of the angular hyperkeratotic lesions
Classification of the
lesion
Diagnosis
Benign lesions
Benign epithelial
hyperkeratosis
41
(36.6%)
Epithelial Dysplasia
Candidal leukoplakia
Verrucous leukoplakia
13
8
3
(11.6%)
(7.14%)
(2.67%)
Total
24
(21.42%)
Verrucous vulgaris
Papilloma
2
2
(1.78%)
(1.78%)
Total
4
(3.57%)
Carcinoma in situ
Verrucous carcinoma
Squamous cell carcinoma
3
4
22
(2.67%)
(3.57%)
(19.64)
Total
29
(25.89%)
Lichen planus
14
(12.5%)
112
(100%)
Premalignant lesions
Number
(per%)
Benign growth
Malignant neoplasm
Dermatosis
Total
Age
Age
Female
range
range
53.2
50.4
23
18
(22-80)
(23-85)
50
60.4
(40-58)
5
(45-75)
8
52.7
2
56
6
(26-90)
1
(47-75)
2
61.5
73
(58-65)
63.1
53.73
8
16
(45-75)
(26-90)
11
1
1
20
46
2
0
0
(42-50)
28.5
3
1
20
(11-50)
58
(46-70)
1
60
2
60.75
0
0
4
(48-73)
8
55
14
58.4
(40-72)
(42-81)
59
57.5
20
9
(42-81)
(40-75)
53.6
55.8
8
6
(24-85)
(25-60)
62
53
50
40.5
(55.4%) (11-85) (44.6%) (20-90)
Male
Table 2: The factors associated with angular hyperkeratotic lesions
Diagnosis
Gender
number
Smoker
Alcohol
Benign
hyperkeratosis
F
M
F
M
F
M
F
M
F
M
F
M
F
M
F
M
F
M
F
M
18
23
8
5
6
2
2
1
1
2
0
4
8
14
1
1
0
2
6
8
112
(100%)
6
18
5
4
4
2
1
0
1
1
0
3
4
8
0
0
0
0
1
3
61
(54.60%)
0
3
0
1
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
1
6
(0.05%)
Epith.dysplasia
Candidal
leukoplakia
Verrucous
leukoplakia
Carcinoma in
situ
Verrucous
carcinoma
Squamous cell
carcinoma
Verrrucous
vulgaris
Papilloma
Lichen planus
Total
Oral Diagnosis
55
Dental
Irritation
8
11
5
3
3
2
0
0
1
1
0
3
2
6
0
0
0
1
1
2
49
(43.70%)
Prosth.
7
9
4
3
2
1
0
0
0
0
0
0
0
3
0
0
0
0
2
1
32
(28.5%)
Systemic
Disease
7
6
3
2
2
0
1
0
0
0
0
1
6
6
0
0
0
0
4
2
40
(35.70%)
Angular
Chelitis
4
5
5
3
5
4
1
1
1
1
0
1
7
12
0
0
0
0
1
3
54
(48.20%)
Vol. 24(2), 2012
Pre-implant computed
Pre-implant computed tomography and insertion torque
measurement in qualitative determination of trabecular
bone density
Mahmood J. Hamzah, B.D.S. (1)
Jamal A. Al-Taei, B.D.S., M.Sc. (2)
ABSTRACT
Background: Bone density is a very important factor in the successful plan of implant treatment. The aim of the study
is to evaluate the trabecular bone density of potential dental implant sites in different region of the jawbone by using
Computerized Tomography (CT) , and the relationship between bone density and insertion torque.
Materials and method: In this clinical study 64 patients were treated with 120 Xive FRIADENT DENTPLY system implants.
The implant recipient sites were divided in two groups according to gender; 60 in males and 60 in females and each
group was divided into subgroups according jaw (maxilla and mandible) and region (anterior and posterior). The
bone density of each implant recipient site was recorded in Hounsfield units (HU) using CT. The maximum insertion
torque (Ncm) values were recorded with torque controlling motor.
Results: There was a significant correlation between bone density and insertion torque in males (r=0. 983, p <0.001)
and females (r=0.955, p <0.001).The trabecular bone density values were (682±98 HU, 481±104 HU, 413±92 HU, and
263±67 HU) values in the anterior mandible, posterior mandible, anterior maxilla, and posterior maxilla, respectively.
Trabecular bone density was higher in males in comparison to females and the bone quality was higher for the
mandible than for the maxilla, and higher for the anterior region than for the posterior region of these bones. In
females there is no significant difference in bone density (p<0.05) between the posterior mandible and anterior
maxilla and between males and females at posterior maxilla (p<0.001).
Conclusion: Trabecular bone density is a key determinant for clinical success; CT is a useful tool for assessing the
bone density
Key words: dental implants, computerized tomography, insertion torque, bone density. (J Bagh Coll Dentistry
2012;24(2):56-61).
Some researchers have reported that CT is a
good tool for evaluating the bone density at
potential dental implant sites (2, 4, 7, 9–17). The
quality of bone in the jaw has been studied
previously (4, 9, 11) but not in the Asian population.
The aim of this study was therefore to evaluate
the trabecular bone density of potential dental
implant sites in different regions of the Iraq
jawbone using CT images.
INTRODUCTION
Dental implants have become a popular
alternative in oral rehabilitation in the past two
decades; even though the clinical outcome of an
implant is influenced by many factors, including
the implant body, skill of the surgeon, and the oral
environment. The key factor for success is the
primary stability at implant placement. The
quality of the alveolar bone is the most important
factor for achieving good primary stability (1, 2).
There are many different definitions of bone
quality, but it is generally presented as the sum of
all of the characteristics of bone that influence its
resistance to fracture (3). The term ‘bone quality’
was introduced to refer to the different bone
density types. In the field of dentistry, Lekholm
and Zarb classified jawbone density into four
types based on the amounts of cortical bone
versus trabecular bone evident on pantograph film
(4, 5)
. Computed tomography (CT) is one of the
most useful medical imaging techniques for
assessing not only the structure of the body tissue,
but also its density. Theoretically, the bone
density, which is measured in Hounsfield units
(HU), is directly related to the tissue attenuation
coefficient (6–8).
A total of 73 Iraqi patients aged 23-45 years
old, males and females, attend our private clinic in
Holy Karbala’ City. The study extended from
November 2010 to July 2011. Out of these73
patients full or partial edentulous, 64 subjects (31
males & 33 females) were included in this study.
The implant recipient sites (120) were divided in
two groups according to gender; 60 implant
recipient sites in males and 60 implant recipient
sites in females and each group was divided into
subgroups according to the jaws (maxilla and
mandible) and regions (anterior and posterior).15
in anterior maxilla, 15 in posterior maxilla, 15 in
anterior mandible and 15 in posterior mandible.
Selective criteria of study sample:
The patients were selected according to
medical and potential implant site evaluation as
follows:
(1) Master Student, College of Dentistry, University of Baghdad.
(2) Assistant Professor, Department Oral Radiology, College of
Oral Diagnosis
56
Vol. 24(2), 2012
a- Medical evaluation:
Sample individual should have no history of
any systemic disease that might affect bone
metabolism like
1- Diabetes Mellitus.
2- Tuberculosis.
3- Cushing's syndrome.
4- Hyperparathyroidism.
5- Generalized osteoporosis.
6- Heavy smokers.
7- In patients with a long period of time
having steroid therapy.
8- Radiotherapy (60GY) in patients with
head and neck cancers (18-20).
b- Potential implant site:
1-The Region of interest is larger than
9.6mm².
2- Diameter greater than 3.5mm.
3- longer than 6 mm in the alveolar
trabecular bone.
Material
X-ray machine
A spiral Computed Tomography (CT)
machine (GE LighSpeed VCT, 64 slice, USA) (in
IRAQI MEDICAL CENTER- Holy KERBALA
City) which will be calibrated daily according to
the manufacturer's instruction.
A range of 5 cm will be covered in 9.9 seconds,
Kv 140, mA 334, rot 0.50 second, slice width 1.25
mm and pixel size 512x512.
Dental implant:
The dental implants used in this study are
XiVE Dentsply Friadent system. XiVE implants
are available in diameter D 3.0- D 5.5 mm and in
lengths of 8-18 mm.
Torque controlling motor:
High torque micro motor (FRios unit Si
DENTSPLY FRIADENT), (W&H; Austeria) and
contra-angle speed reduction (20:1) hand piece
(W&H; Austria).
Statistical data analysis:
The data were processed and analyzed using
SPSS (Statistical Package for Social Sciences)
version 19 computer software.
A. Use t-test to compare the mean of two
groups (males and females).
B. Pearson correlation to test the linear
relationship between each two variables
(average bone density and insertion
torque).
C. ANOVA test to test for differences in
means of more than two groups. When
the result proves significant this would be
followed by LSD test.
D. LSD (Least significant difference test) to
check which two groups are different
Oral Diagnosis
(anterior mandible, posterior mandible,
anterior maxilla and posterior maxilla.
E. P value of less than the 0.05 level
(P<0.05) of significance was considered
statistically significant.
RESULTS
1-Relation between the average bone density
(BD) and the maximum insertion torque
(torque) in males and females
The BD and torque in males (541±229 HU, 33±8
N cm) were higher than females (378±123 HU, 27
±4 Ncm) and highly significant difference
between males and females as shown in table (1).
There is significant correlation between average
bone density and maximum insertion torque in
males and females table (2).
2- Relation between the maxilla and mandible
in average bone density (BD) and the
maximum insertion torque.
BD and the torque were significantly higher in the
mandibles (581±202 HU, 35±4 N cm) in
comparison to the maxillae (338±80 HU, 26±3 N
cm) and highly significant difference between
mandibles and maxillae. There is significant
correlation between average bone density and the
maximum insertion torque in maxillae and
mandibles table (3).
There is significant correlation between BD and
the torque in maxillae and mandibles table (4).
3- Relation between the maxilla and mandible
in average bone density and the maximum
insertion torque at each region in males and
females
In males
Higher BD and the torque had been found in the
anterior mandible followed by the posterior
mandible, then anterior maxilla and the last
posterior maxilla. For the differences among the
four regions in males figures (1) & (2); ANOVA
test show a high significant difference in the BD
and the torque in regions (p< 0.01). The LSD test
also shows a high significant difference in the BD
and the torque in each region in relation to others.
In females
Higher BD and the torque had been found in
anterior mandible followed by the posterior
mandible, then anterior maxilla, and the last
posterior maxilla. For the differences among the
four regions in females' figures (1) & (2).
ANOVA test shows a highly
significant
difference in the BD and the torque in regions.
The LSD test also shows a no significant
difference in the BD and the torque between the
posterior mandible and the anterior maxilla
(p<0.05).
57
Vol. 24(2), 2012
including the measurement of the bone mineral
contents in the jaws and forearms have already
indicated that, when compared to the males, lower
bone mineral densities in females have been
found throughout adult life (33). However, this
finding is in agreement with (28,34).
In the present study, the difference in the
average bone density of the implant recipient sites
between the mandibles (581±202 HU) and the
maxillae (338±80 HU) was statistically of high
significance for all patients, this finding is in
agreement with (35), who reported that the
difference in the average bone density of the
implant sites between the mandibles (828 ± 245
HU) and the maxillae (582 ±192 HU) was
statistically significant for all patients.
The mean bone densities recorded in this study
are lower than those reported by (35, 36) table (1),
which might be due to the previous measurements
including the trabecular bone and the outer
cortical shell. The density of cortical bone is
significantly higher than that of trabecular bone.
However, we observed higher mean bone
densities than did (37), which might be due to the
use of different types of software. In the two
studies de-Oliveira et al indicated that this could
yield different bone density values from the same
CT images.
In addition, the ranges of the mean bone
density in the present study are broadly consistent
with those of (38, 39) table (5). The differences
between the present study and the previous
studies come from the distribution of implant
recipient sites. Because the effect of number of
implant sites in region was neglected in previous
studies.
As the bone is reduced in volume to C shape
minus height (C-h), especially in the anterior
mandible. The C-h mandible often exhibits an
increase in torsion or flexure in the anterior
segment between the mental foramens during
function. This increased strain causes the bone to
increase in density (40). In this study and all
previous studies was found that most density was
in the anterior mandible (35-39).
The bone density recorded in the present
study were (682±98 HU, 481±104 HU, 413±92
HU, and 263±67 HU) values in the anterior
mandible, followed by the posterior mandible,
anterior maxilla, and posterior maxilla,
respectively.
Shapurian et al. (38) found that the mean bone
density was lower in the posterior mandible than
in the posterior maxilla (in contrast to the results
of the present study). These discrepancies might
have resulted from the distribution of implant
recipient sites, because a relatively high number
Figure 1: Box chart average of bone density
in different regions in males and females
Figure 2: Box chart maximum insertion
torques in different regions in males and
females.
DISCUSSION
Bone density
Many studies have demonstrated that the
survival rate of an implant is significantly affected
by the host bone quality (21-25), and hence a
preoperative evaluation of the bone condition is
essential for assisting the dentist when planning
implant therapy.
The use of CT, which is more objective and
reliable for the assessment of the bone density of
the patients requiring implant therapy, was
introduced (26).
In this study, alveolar trabecular bone density
was evaluated in different regions of the jawbone
from spiral CT images.
It is not passable to make a direct comparison
between the present study and previous studies
because many previous studies on the bone
density from CT included cadaver specimens (2932)
.
In the present study, the male patients had a
higher average bone density value at the implant
sites than that in female patients (the mean of
average bone density of all implant recipient sites
was (541±229 HU in males; while in females
378±123 HU), there was a statistically higher
significant difference in the average bone density
of implant sites between males and females.
This finding may be explained with the
hormonal peculiarities in females and generally
higher bone mass in males. Previous studies
Oral Diagnosis
58
Vol. 24(2), 2012
with dental quantitative CT prior to dental implant
placement in cadaver mandibles: pilot study.
Radiology 2002; 224:247–52.
8. Chen WP, Hsu JT and Chang CH. Determination of
Young’s modulus of cortical bone directly from
computed tomography: a rabbit model J Chin Inst
Eng 2003; 22:121–8.
9. de Oliveira RC, Leles CR, Normanha LM, Lindh C. and
Ribeiro- Rotta RF. Assessments of trabecular bone
density at implant sites on CT images. Oral Surg Oral
Med Oral Pathol Oral Radiol Endod 2008; 105:231–
8.
10. Norton MR and Gamble C. Bone classification: an
objective scale of bone density using the
computerized tomography scan. Clin Oral Implants
Res 2001; 12:79–84.
11. Turkyilmaz I, Tozum TF and Tumer C. Bone density
assessments of oral implant sites using computerized
tomography. J Oral Rehabil 2007; 34:267–72.
12. Iwashita Y. Basic study of the measurement of bone
mineral content of cortical and cancellous bone of the
mandible by computed tomography. Dentomaxillofac
Radiol 2000; 29:209–15.
13. Loubele M, Maes F, Schutyser F, Marchal G, Jacobs R
and Suetens P. Assessment of bone segmentation
quality of cone-beam CT versus multislice spiral CT:
a pilot study. Oral Surg Oral Med Oral Pathol Oral
Radiol Endod 2006; 102:225–34.
14. Shahlaie M, Gantes B, Schulz E, Riggs M and Crigger
M. Bone density assessments of dental implant sites:
1. Quantitative computed tomography. Int J Oral
Maxillofac Implants 2003; 18:224–31.
15. BouSerhal C, Jacobs R, Quirynen M and van
Steenberghe D. Imaging technique selection for the
preoperative planning of oral implants: a review of
the literature. Clin Implant Dent Relat Res 2002;
4:156–72.
16. Turkyilmaz I, Tozum TF, Tumer C and Ozbek EN.
Assessment of correlation between computerized
tomography values of the bone, and maximum torque
and resonance frequency values at dental implant
placement. J Oral Rehabil2006; 33:881–8.
17. Turkyilmaz I and McGlumphy EA. Is there a lower
threshold value of bone density for early loading
protocols of dental implants? J Oral Rehabil2008;
35:775–81.
18. Wagner W, Esser E, Ostakamp K. Osseointegration of
Dental Implant in Patients with and without
Radiotherapy. Acta Oncol 1998; 37(7-8):693-6.
19. Harry D and Ogle OE. Atlas of Minor Oral Surgery.
Text book, Mosby Company 2001; p219-41.
20. Jeffcoat MK. The association between osteoporosis
and oral bone loss. J Periodontol 2005; 76(11):21, 2532.
21. Jaffin RA & Berman CL. The excessive loss of
Branemark fixtures in type IV bone: a 5-year
analysis. J Periodontol 1991; 62:2–4.
22. Johns RB, Jemt T, Heath MR, Hutton JE, McKenna S
& McNamara DC. A multicenter study of over
dentures supported by Branemark implants. Int J Oral
Maxillofac Implants 1992; 7:513–22.
23. Lazzara R, Siddiqui AA, Binon P, Feldman SA,
Weiner R & Phillips R. Retrospective multicenter
analysis of 3i endosseous dental implants placed over
a five-year period. Clin Oral Implants Res 1996;
7:73–83.
of their implant recipient sites were in the
posterior mandible which has the lowest bone
density values.
In this study, it has been observed that the
average bone density value of the implant sites in
the anterior regions of jaws was higher than that
in the posterior regions (anterior mandible–
posterior mandible; anterior maxilla–posterior
maxilla).
This finding is in conformity with those
reported by (35-39).
In the present study there is no significant
difference in the mean bone density between the
anterior maxilla and the posterior mandible in
females, while in males there was a statistically
significant between the posterior mandible and the
anterior maxilla. This finding is partially in
agreement with (35); stated that there are
differences in the average bone density of the
implant sites that was not statistically significant
between the posterior mandible and the anterior
maxilla.
Insertion torque
The insertion torque is the latest value seen on
the screen was recorded. Starting from 20Ncm,
the insertion torque was increased in steps of
5Ncm, when the rotation stopped due to friction
before the implant was fully inserted. Only a
limited amount of torque could be applied in order
to avoid mechanical overload of the equipment on
bone tissue.
Statistically significant strong correlations
between bone density and insertion torque were
found at implant placement. This fact concurs
with the previous studies (36, 39, 41, 42).
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Rand WM. Quantitative evaluation of bone density
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Implants 2006; 21:290–7.
5. Lekholm U and Zarb GA. Patient selection and
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T, eds. Tissue integrated prostheses: osseointegration
in clinical dentistry. Chicago: Quintessence
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6. Hounsfield GN. Computerized transverse axial scanning
(tomography). 1. Description of system. Br J Radiol
1973; 46:1016–22.
7. Homolka P, Beer A, Birkfellner W, Nowotny R and
Gahleitner A. Bone mineral density measurement
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24. Schenk RK & Buser D. Osseointegration: a reality.
Periodontol1998; 17:22–35.
25. Tolstunov L. Implant zones of the jaws: implant
location and related success rate. J Oral Implantol
2007; 33:211–20.
26. Schwarz M. S, Rothman SLG, Rhodes M L & Chafetz
N. Computed tomography: part I. Preoperative
assessment of the mandible for endosseous implant
surgery. Intern J Oral and Maxillofacial
Implants1987; 2: 137–41.
27. Beer A, Gahleitner A, Holm A, Tschabitscher M &
Homolka P.
Correlation of insertion torques with
bone mineral density from dental quantitative CT in
the mandible. Clinical Oral Implants Res 2003;
14:616–20.
28. Ikumi N & Tsutsumi S. Assessment of correlation
between computerized tomography values of the
bone and cutting torque values at implant placement:
a clinical study. International Journal of Oral and
Maxillofacial Implants 2005; 20: 253–60.
29. Shahlaie M, Gantes B, Schulz E, Riggs M & Crigger
M. Bone density assessments of dental implant sites:
1. Quantitative computed tomography. Intern J Oral
and Maxillofacial Implants2003; 18:224–231.
30. Fanuscu MI & Chang TL. Three dimensional
morphometric analysis of human cadaver bone:
microstructural data from maxilla and mandible.
Clinical Oral Implants Res 2004; 15: 213–8.
31. Hanazawa T, Sano T, Seki K & Okano T. Radiologic
measurements of the mandible: a comparison
between
CT-reformatted
and
conventional
tomographic images. Clinical Oral Implants Res
2004; 15: 226–32.
32. Aranyarachkul P, Caruso J, Gantes B, Schulz E, Riggs
M, Dus I, Yamada JM & Crigger M. Bone density
assessments of dental implant sites: 2. Quantitative
cone-beam computerized tomography. Intern J Oral
and Maxillofacial Implants 2005; 20: 416–24.
33. Von Wovern N, Westergaard J & Kollerup G. Bone
mineral content and bone metabolism in young adults
with severe periodontitis. J Clin Periodontol 2001;
28:583–8.
34. Turkyilmaz I, Tozum TF and Tumer C. Bone density
assessments of oral implant sites using computerized
tomography. J Oral Rehabil 2007a; 34:267–72.
35. Turkyilmaz I, Tumer C, Ozbek EN & TÖzüm TF.
Relation between the bone density values from
computerized tomograghy, and implant stability
parameters: a clinical study of 230 regular platform
implants. J Clin periodontal 2007b; 34: 716-22.
36. Turkyilmaz I & Mcglumphy E. Is there a lower
threshold value of bone density for early loading
protocols of dental implants? J Oral Rehab 2008;
35:775-81.
37. de Oliveira RC, Leles CR, Normanha LM, Lindh C &
Ribeiro-Rotta RF . Assessments of trabecular bone
density at implant sites on CT images. Oral Surg Oral
Med Oral Pathol Oral Radiol Endod 2008; 105:231–
8.
38. Shapurian T, Damoulis PD, Reiser GM, Griffin TJ &
Rand WM. Quantitative evaluation of bone density
using the Hounsfield index. Int J Oral Maxillofac
Implants 2006; 21:290–7.
39. Fus H, Chen K, Shen M, Shen T & Hsu J. Variations
in bone density at dental implant sites in different
regions of the jawbone. J Oral Rehab 2010; 2:121-32.
40. Misch CE. Early crestal bone loss etiology and its
effect on treatment planning for implants. J postgred
Dent 1995; 2(3):3-17.
41. Turkyilmaz I, Sennerby L, Tumer C, Yenigul M, Avci
M. Stability and marginal bone level measurements
of un splinted implants used for mandibular
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clinical study comparing early and conventional
loading protocols. Clin Oral Implants Res 2006a;
17:501–505.
42. Turkyilmaz I, Tozum TF, Tumer C & Ozbek EN.
Assessment of correlation between computerized
tomography values of the bone, and maximum torque
and resonance frequency values at dental implant
placement. J Oral Rehabilitation 2006b; 33:881–8.
Table 1: Comparison of BD and torque in males and females at level (p <0.01).
Males and
t
Sig.
females
4.840 0.0005
BD
Torque 4.364 0.0005
Table 2: Correlation between average bone density and maximum insertion torque in males and
females at the (p<0.01) level.
Gender
Males Females
Torque Torque
Pearson correlation 0.983 0.955
BD
0.0005 0.0005
Sig.
Table 3: Comparison of BD and torque in mandibles and maxillae at level (p <0.01).
Maxilla & Mandible
BD
torque
Oral Diagnosis
t-test for Equality of Means
t
Sig.
8.62
0.0005
8.01
0.0005
60
Vol. 24(2), 2012
Table 4: Correlation between BD and torque in Maxilla & Mandible at the (p<0.01) level.
Maxilla & Mandible
BD Pearson correlation
Sig.
N.
torque
0.938
0.0005
120
Table 5: Reference that shows bone densities in different regions of the jawbone [expressed in
Hounsfield units (HU); numbers within parentheses are sample sizes]
Anterior
mandible
Region
Posterior
mandible
Anterior
maxilla
Posterior
maxilla
Shapurian et al.
559±208(42) 321±1132(78)517±177(45) 333±119(54)
(2006)
Turkyilmaz et al.
945±207(58) 674±227(28) 716±190(28) 455±122(21)
( 2007a)
Turkyilmaz&
846±234(100) 526±107(60) 591±176(70) 403±95(70)
Mcglumphy (2008)
de-Oliveira et al.
383±243(6) 306±187(28) 370±176(6) 255±184(29)
(2008)
Fus et al. (2010) 530±161(15) 359±150(55) 516±132(47) 332±136(37)
682±98(30) 481±104(30) 413±92(30) 263±67(30)
This study
Oral Diagnosis
61
Vol. 24(2), 2012
Evaluation of oral health
Evaluation of oral health status in a sample of autistic
male children
Mayyadah H. Rashid, B.D.S., M.Sc.(1)
Raja H. Al-Jubouri, B.D.S., M.Sc., Ph.D. (2)
ABSTRACT
Background: Autism is a severe neurodevelopmental disorder, presents in early childhood, characterized by severe
impairments in socialization, communication and behavior. Autism is considered a multi-factorial disorder that is
influenced by genetic, environmental, and immunological factors with oxidative stress as a mechanism linking these
factors. Assessment of any oral manifestations has to be discovered, evaluated and measured in autistics to be used
as a potential diagnostic.
Materials and methods: Oral health status:(DMFT) for permanent teeth, (dmft)for deciduous teeth and gingival
indices were estimated for 58 individuals aged (2-13) years, twenty nine of them were autistics and twenty nine were
sex and age matched healthy controls.
Results: The results of this study showed that Iraqi autistic children sample was more likely to be caries-free compared
with healthy sample.
Conclusion: Children with autism spectrum disorder (ASD) were more likely to be caries-free, had lower DMFT\ dmft
and GI scores than did their unaffected peer and can be used in autism spectrum disorder prediction to a limited
extent.
Key words: Autism spectrum disorder; Oral health status. (J Bagh Coll Dentistry 2012;24(2):62-65).
INTRODUCTION
Given the well-established fact that mercury (Hg)
is known to significantly increase oxidative stress
and that fetuses and infants are routinely exposed
to Hg from environmental sources (fish, dental
amalgams, etc.), investigators have described that
many ASDs may result from a combination
ofgenetic/biochemical susceptibility, specifically
areduced ability to excrete Hg, and exposure to
Hg at critical developmental periods.Further, it
was reported that Hg can cause immune, sensory,
neurological, motor, and behavioraldysfunctions
similar to traits defining/associated with ASDs,
and that these similarities extend to
neuroanatomy,
neurotransmitters,
and
biochemistry. Also, it was reported when
reviewing the molecular mechanisms of Hg
intoxication that it can induce death,
disorganization and/or damage to selected neurons
in the brain similar to that seen in recent ASD
brain pathology studies, and this alteration may
likely produce the symptoms by which ASDs are
diagnosed(6).
Autism spectrum disorders (ASDs) are prevalent
neurodevelopmental disorders that affect an
estimated 6 per 1,000; with male to female ratio
averages 4.3:1, which means that boys are at
higher risk for ASD than girls (1).Characterized by
severe impairments in socialization, communication and behavior. Children diagnosed with an
ASD may display a range of problem behaviors
such as hyperactivity, poor attention, aggression
and self-injury. In addition, to unusual responds to
sensory stimuli such as hypersensitivities to light
or certain sounds, colors, smells or touch and have
a high threshold for pain(2).Finally, common comorbidity conditions often associated with ASDs
include gastrointestinal and autoimmune disease
(3)
.
Investigators suggested that ASDs may result
from
an
interaction
between
genetic,
environmental and immunological factors, with
oxidative stress as a mechanism linking these risk
factors (4).
Oral health and dental needs of children
withautism have been evaluated by very few
investigators. The studies conducted on this topic
reported nostatistically significant differences in
the prevalence of caries, fillings, gingivitis and
degree of oral hygiene in comparison with nonautistic individuals8, and even a lower incidence
of caries in some of the reports(5).
(1)
(2)
Sixtyindividuals from Central Pediatric Teaching
Hospital in Al-Iskanwere enrolled in this study.
They were categorized into two groups:
Autistic group: Composed of 31 children (29
males and 2 females) who were diagnosed as
autistic children, their ages range between 2-13
years. Because the female sample very small, it
was excluded from the current study.
Healthy control group: Composed of 29 age and
gender matched male children.
M.Sc. Oral medicine, Specialist in Ministry of Health.
Professor, Department of Oral Diagnosis , College of
Oral Diagnosis
62
Vol. 24(2), 2012
All individuals were evaluated by full medical
history and clinical examination to exclude any
other systemic disease that may affect the
parameters examined in this study. Oral and
periodontal examination was done for each
individual and any child with symptoms and signs
of any active oral inflammation and advanced
periodontitis were excluded.
All parents were supplied with informed consent
and the purposes of the study wereexplained to
them.All the children subjected to extra-oral
examination for any scars or trauma to the head,
neck, hands and fingers; taking medical, family
history and previous dental history.Intra-Oral
assessment of caries experience through the
application of decayed, missing and filled teeth
Index (DMFT) and (dmft) for permanent and
primary teeth respectively; and assessment of
gingival health status through gingival index (7).
All data were statistically analyzed using SPSS
version 13 (Statistical Package for Social
Sciences). Non-normally distributed quantitative
variables (DMFT\dmf score) are described by
median and interquartile range. The remaining
quantitative variables (age and gingival index)
were normally distributed and thus conveniently
described by mean ± standard deviation.
Correlation assessment was performed using the
Spearman correlation analysis. The ROC analysis
was used to rank the quantitative parameters from
those with highest difference between Autism
cases and healthy controls to lowest difference.
This is done by ranking the ROC area of different
parameters. Statistical significance was defined as
p< 0.05.
According to criteria, 96,6% of autistic
children had mild gingivitis with mean value
(0.55 ± 0.35) obviously lower in comparison to
healthy controls (0.75 ± 0.48), but the difference
failed to reach the level of statistical significance
(p=0.08).
Tables2 and 3 summarize an assessment of
DMFT, dmft and GI scores among the study
subjects with ASD in comparison to the
controls.Table 4 showing the tested variables
ordered according to their significance in
separating between autistics and healthy controls
(ROC test).
DISCUSSION
Boys are at higher risk for ASD than girls and this
agreed with all other studies around the world (1,
3)
. As part of the multiple unknown developmental abnormalities, children diagnosed with
autism practice self-injurious behavior (SIB) at
some stage in their lives. In the present study
results of the extra oral assessment, types of
habits, trauma and injuries revealed that out of the
29 examined children, only 2 (6.9 %) practice this
behavior, and this result was in good agreement
with many other studies (8,9). Heritability
contributes about 90% of the risk of a child
developing autism,and this support the findings in
the present study in which 21 (72.4 %) of autistic
children have a positive family history of
neuropsychiatric
illness like schizophrenia,
Alzheimer’sdisease,
mental
disorder
and
depression(10).
In the present study 28 children (96.6%) had
never visited dental clinic or received dental
treatment and follow upand
this could be
explained by the fact that people with ASD
incapable of cooperating in the dentalsetting
owing to their impaired social interaction and
communicationskills. In addition to cognitive
dysfunction, aggression and other associated
psychiatric symptoms may impede the provision
of dental care. This result was in good agreement
with many studies (11-14).
The current study revealed that caries severity
(but failed to reach statistical significant level) in
autistics were lower than in unaffected children
with autism, because of their ritualistic
behaviorwhich characterized by unvarying pattern
of daily activities, such as an unchanging menu so
they are moreregular in their behavior at meals
than are unaffected children.Therefore, a lower
frequency of snacking between meals and
lowerintake of carbohydrates could have
contributed to the lowercaries rate observed and
this finding agreed with several studies (9,
15)
.While disagreed with others who reported
RESULTS
The mean age for autistic children was about
5.9±3.4 years. Autistics and their controls showed
homogeneity and there were no significant
difference between the two groups.
Extra-Oral Examination: out of 29 autistics only 2
(6.9%) showed signs of trauma due to self-injury
habit. Parents' responses to the questionnaire
regarding dental visits indicated that 28 (96.6%)
of autistic children never visited dental clinic and
had a negative history of treatment and follow up
as shown in table (1).
Intra – Oral Examination: The caries severity of
children in the ASD group was statistically
significantlower than that in the unaffected group
for dmft(p = 0.013) but insignificant for DMFT (p
= 0.73). Regarding caries prevalence, a total of 15
(51.7%) childrenin the ASD group had a positive
caries free history (DMFTand dmft=0), compared
with9 (31%) children in healthy control group.
Oral Diagnosis
63
Vol. 24(2), 2012
higher scores in autistic groups (5, 16). Caries
prevalence lower in autistic children participating
in the present study and this result were in good
agreement with many previous studies (9, 5).
Gingival status of the autistic children in the
present study showed that (96,6%) of the children
had generalized mild gingivitis, which it was in
good agreement with many previous studies (5,16).
While Ozdemir-Ozenenand Sandalli, 2007 (17), in
their study reported that the gingival index records
of the children with autism was found to be
significantly higher than the healthy children.
All these findings could be related to many
reasons such as the irregular brushing habits
because of the difficulties the trainers and the
parents encountered when they brushed the
children's teeth. It could also be due to lack of the
necessary manual dexterity of autistic children
during brushing by themselves, which made their
tooth brushing inefficient. Furthermore, the
findings of this study reflect poor dental
awareness, a lack of dental education and
deficiency in receiving oral hygiene instructions
from dental staff. Care-givers need to know the
different techniques and materials of tooth
brushing with emphasis on behavior modification
to control the behavior of the children and regular
dental visits.
In the present study, aim was directed to assess
and measure any oral manifestations associated
with ASD, which could be used for the early
diagnosis and intervention with autism. Although
there is no known cure, but early behavioral or
cognitive intervention can help autistic children
gain self-care, social, and communication skills.
Up to our knowledge, this study is the first of its
kind that evaluate the usefulness of oral health
status as diagnostic aid through measuring the
DMFT, dmft and GI under condition of stress due
to autism in a sample of Iraqi autistics.
The ROC test results of this study revealedthat the
areas under ROC curve for DMFT (0.521) was
not significantly different from 0.5 value of an
equivocal test (p = 0.79).And for dmft was
significantly higher (0.669) from 0.5 value of an
equivocal test (p = 0.027). ), while the areas under
ROC curve for GI was higher (0.669) from 0.5
value of an equivocal test, but statistically
insignificant (p = 0.11).So dmft ranked number
onefollowed by GI then DMFT as ranked third in
order of importance in this study as shown in table
(3).
REFERENCES
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
Oral Diagnosis
64
Newschaffer CJ, Croen LA, Daniels J et al. the
epidemiology of autism spectrum disorders. Annu
Rev Public Health 2007; 28:235–58.
Austin D. An epidemiological analysis of the ‘autism
as mercury poisoning’ hypothesis. International
Journal of Risk and Safety in Medicine 2008; 20:13542.
Geier, Kern, Geier. A prospective study of oxidative
stress biomarkers in autistic disorders. Electronic J
Applied Psychology 2009; 5(1): 2-10.
James SJ, Melnyk S, Jernigan S, Cleves MA, Halsted
CH, Wong DH, Cutler P, Bock K, Boris M,
Bradstreet JJ, Bake SM, Gaylor DW. Metabolic
endophenotype and related genotypes are associated
with oxidative stress inchildren with autism.
American Journal of Medical Genetics, Part B:
Neuropsychiatric Genetics 2006; 141: 947-56.
Ebtissam Zakaria Murshid. Oral health status, dental
needs, habits and behavioral attitude towards dental
treatment of a group of autistic children in Riyadh,
Saudi Arabia. Saudi Dent J 2005; 17: 3.
Geier DA, King PG, Sykes LK, & Geier MR. A
comprehensive review of mercury provoked autism.
Indian J Medical Res 2008; 128: 383-411.
Silness J, Löe H. Periodontal disease in pregnancy II
correlation between oral hygiene and periodontal
condition. ACTA OdontolScand 1963; 22:121-135.
Dominick KC, Davis NO, Lainhart J, Tager-Flusberg
H, Folstein S. Atypical behaviors in children with
autism and children with a history of language
impairment. Res DevDisabil 2007; 28(2):145–62.
Cheen Y, Loo, Richard M, Graham, Christopher V,
Hughes. The Caries Experience and Behavior of
Dental Patients with Autism Spectrum Disorder. J
Am Dent Assoc 2008; 139: 11: 1518-24.
Freitag CM. The genetics of autistic disorders and its
clinical relevance: a review of the literature. Mol
Psychiatry 2007; 12(1):2–22.
Barbaresi WJ, Katusic SK, Voigt RG. Autism: a
review of the state of the science for pediatric
primary health care clinicians. Arch Pediatr Adolesc
Med 2006; 160(11):1167–75.
Friedlander AH, Yagiela JA, Paterno VI, Mahler ME.
The neuropathology, medical management and dental
implications of autism. JADA 2006; 137(11):1517–
27.
Marshall J, Sheller B, Williams BJ, Mancl L, Cowan
C. Cooperation predictors for dental patients with
autism. Pediatr Dent 2007; 29 (5): 369–76.
Pilebro C, Backman B. Teaching oral hygiene to
children with autism. Int J Paediatr Dent 2005; 15
(1):1–9.
Lam KSL, Aman MG. The Repetitive Behavior
Scale-Revised: independent validation in individuals
with autism spectrum disorders. J Autism Dev Disord
2007; 37(5):855–66.
De Mattei R, Cuvo A, Maurizio S. Oral assessment of
children with an autism spectrum disorder. Journal of
Dental Hygiene 2007; 81: 3.
ÖzdemirÖzenen D, Çıldır ŞK, Sandallı N. The oral
health status of children with visual impairment. 12th
Congress of the BaSS, İstanbul, Türkiye; 2007.P.1214.
Vol. 24(2), 2012
Table 1: Extra-oral examination and case history of autistics
Conditions
self-injurious behavior and signs of trauma
Family history of neuropsychiatric disorders
Rubella Vaccine
previous dental experience
No. of +ve
cases
2
21
29
1
%
6.9 %
72.4 %
100 %
3.4 %
No. of -ve
cases
27
8
0
28
Table 2:Mean±SD for tested parameters
Markers
Gingival index
Cases
0.55 ± 0.35
Controls
0.75±0.48
p
0.08 [NS]
Table 3: Median level for selected parameters
Markers
DMF
dmf
Cases
0
0
Controls
0
1
p
0.73[NS]
0.013
Table 4: ROC analysis of testedparameters
parameters
dmf
Gingival index
DMF
Oral Diagnosis
Area under the curve
0.669
0.622
0.521
65
P
0.027
0.11[NS]
0.79[NS]
%
93.1%
27.6%
0%
96.6%
Vol. 24(2), 2012
Ovulation detection
Ovulation detection through salivary levels of sialic acid
and glycosaminoglycans
Rand M. Al-khafagy, B.D.S., M.Sc. (1)
Sahar H. Al-Ani, B.D.S., M.Sc. (2)
Ali Y.Majid, M.B.ch.B., M.Sc., F.I.C.M.S. (3)
ABSTRACT
Background: One in ten couples of reproductive age encounter some level of infertility. Identification of the period
of ovulation in humans is critical in the treatment of infertility. Success in in vitro fertilization and embryo transfer has
been associated with the exact time of ovulation. Saliva is a unique diagnostic fluid, the composition of which
immediately reflects the sympathetic nervous system, parasympathetic nervous system, hypothalamic- pitutaryadrenal axis and immune system response to stress. The study aims at evaluating the changes in salivary sialic acid
and Glycosaminoglycans in the regular menstrual cycle. Thus, the presence of these carbohydrates in the ovulatory
saliva makes the possibility to develop a biomarker for the detection of ovulation by noninvasive methods.
Subjects, materials and methods: Randomly, seventy five volunteer females were recruited and divided into 5
groups; each contains 15 subjects as follow: Nine years old females and postmenopausal females as control groups,
pre-ovulatory period, ovulatory period and post-ovulatory period females as experimental groups. Each female, of
the experimental groups, underwent sonographic examination to estimate her period regarding ovulation.
Unstimulated whole saliva was collected using the spitting method. Colorimetric procedure was used for total sialic
acid determination and for Glycosaminoglycans quantitative determination, the method of ELISA was used.
Results: The concentration of sialic acid was significantly decreased in saliva of females in the ovulatory phase of the
menstrual cycle; whereas, a significant increase in salivary sialic acid concentration was in the post-ovulatory phase.
Glycosaminoglycan concentration showed a gradual increase from the pre-ovulatory phase then ovulatory to reach
its maximum in the post-ovulatory phase with a significant difference between the pre-ovulatory and post-ovulatory
phases. A significant correlation was not found between sialic acid and Glycosaminoglycans in different study
groups.
Conclusions: On the basis of the results arrived at, the study concluded that there are remarkable cyclic variations in
sialic acid and glycosaminoglycans during the menstrual cycle but in conclusion, glycosaminoglycans and sialic
acid salivary levels cannot be used for the precise prediction of ovulation.
Keywords: Ovulation, saliva, sialic acid, glycosaminoglycans. (J Bagh Coll Dentistry 2012;24(2):66-69).
INTRODUCTION
Carbohydrates are the major diet for mammalian
species. The nature of the feeding habit would
have a major impact on the excretion of
biomolecules. This may be the reason for a
considerable release of carbohydrates in the saliva
(3,4)
. Most of the salivary proteins are
glycoproteins. Sialic acid (SA) is one of the
terminal sugars of salivary glycoproteins. It is an
important structural component of salivary
glycoproteins, enhancing bacterial aggregation as
well as participating in the formation of the
acquired pellicle and dental plaque (5). A previous
study suggests that bovine submaxillary mucin
has hydroxyl radical scavenging ability and the
SA in mucin is an essential moiety to scavenge
hydroxyl radicals and mucin synthesis is induced
by oxidative stress (6).
Proteoglycans are macromolecular components of
the extracellular matrix that play various roles in
normal cell physiology and in pathologic states (7).
Modulation of proteoglycan turnover by follicular
stimulating hormone (FSH) and luteinizing
hormone (LH) is mostly related to the ovulatory
process (8). A recent study suggests changes in
salivary glycosaminoglycan (GAGs) and sialic
The cyclic physiologic changes are mainly
brought about by the ovarian hormones estrogen
and progesterone, the levels of which show
variation
during
the
menstrual
cycle.
Identification of the period of ovulation in humans
is critical in the treatment of infertility. Success in
in vitro fertilization and embryo transfer has been
associated with the exact time of ovulation. In the
recent years, attention has been paid to the
noninvasive method in ovulation detection (1).
Saliva is a unique diagnostic fluid, the
composition of which immediately reflects the
sympathetic nervous system, parasympathetic
nervous system, hypothalamic-pituitary-adrenal
axis and immune system response to stress (2).
Recent reports shows that the saliva is a very good
source of both hormones and biochemicals and
that their levels change in accordance with the
menstrual cycle (1).
(1) Ministry of Health, Iraq.
(2) Assistant Professor, department of Oral Medicine, College of
(3) Chemical Pathology
Oral Diagnosis
66
Vol. 24(2), 2012
acid that are parallel to the normal increases in
serum estrogen levels that occur in normal
menstrual cycle (1).
MATERIALS AND MEHODS
This is a cross-sectional study in which seventy
five volunteer females were recruited and divided
into 5 groups; each contains 15 subjects as follow:
Group A: Eight to nine years old females
represent the pre-pubertal period. (Control group)
Group B: Reproductive age females in the preovulatory period. (Experimental group)
Group C: Reproductive age females in the
ovulatory period. (Experimental group)
Group D: Reproductive age females in the postovulatory period. (Experimental group)
Group E: Postmenopausal females (10-20 years
after menopause). (Control group)
Each female, of the experimental groups,
underwent sonographic examination first to
estimate her period regarding ovulation.
Unstimulated whole saliva was collected using the
spitting method (9) for 10 minutes. For total sialic
acid determination, the colorimetric procedure
was used and the optical density was read at 549
nm (540-555nm) and the concentration of sialic
acid was calculated according to standard curve.
For
Glycosaminoglycans
quantitative
determination, the method of ELISA was used,
the absorbance (OD value) was determined at
wave length 540nm and the concentration of GAG
was calculated according to standard curve.
RESULTS
Saliva sialic acid and GAGs concentrations were
almost constant in different age groups and not
related to age.
In the experimental groups, salivary sialic acid
level decreased in the pre-ovulatory phase
compared to control groups. Nadir level was
obvious in the ovulatory phase, and then a sudden
rise was found in the postovulatory phase making
the highest concentration. Fig 1.
A high statistically significant difference between
SA conc. in the ovulatory phase and the postovulatory phase (p= 0.001). Another high
significant difference was found between the
ovulatory phase and the prepubertal group
(p=0.001). A higher significant difference was
found between ovulatory and postmenopausal
group (p=0.0001). The only non-significant value
was between ovulatory and pre-ovulatory periods
(p=0.973).
Salivary GAGs in normal young women
presented a biphasic pattern, with higher
concentration values during the second half of the
Oral Diagnosis
67
Ovulation detection
menstrual cycle. In the experimental groups, the
lowest salivary GAGs level was in the preovulatory phase compared to control groups
followed by a gradual increase in the ovulatory
phase and the peak level was in the post-ovulatory
phase as shown in fig 2. A statistically significant
difference was found between the pre-ovulatory
phase GAGs level and the post- ovulatory phase
level (p=0.013). Also the levels showed a high
significant difference between the pre-ovulatory
phase and the postmenopausal group (p=0.0001).
No significant differences were found among the
other groups.
DISCUSSION
Sialic acid
According to this study, SA level in old age group
(above 45) were almost similar to that of children
(8-9 years old) and are also not far away from its
level in young adult except for its level in the
post-ovulatory phase. This means that salivary
sialic acid concentrations are almost constant and
not related to age. This is in accordance with
another study that found similar SA concentration
from birth to adulthood (10). Meanwhile, this result
is a disagreement with two other studies (11, 12) that
stated that SA in human unstimulated saliva was
affected by age with a trend toward reduction in
SA concentration with age. The result of this
study is also a disagreement with Narhi et al. (13)
who stated that the concentration of SA and
salivary peroxidase was highest in the oldest age
group.
As mentioned, the results of the present study
revealed low concentration of SA in the preovulatory phase saliva; this is in accordance with
two old studies that had observed decreased
concentrations of SA both in human cervical
mucus (14), and human whole saliva in this phase
(15)
. Nadir concentration in the ovulatory phase
was found in this study and this is in accordance
with Moghissi and Syner (16). Then a sudden rise
to peak in the post-ovulatory phase; this is
probably due to consumption of SA from the
blood by the cell membranes of the growing
follicles where it predominates because SA is a
monosaccharide component of cell membranes
(17)
, so the consumed SA in the pre-ovulatory and
ovulatory phases is more than the produced or
gained. After the rupture of the dominant follicle
“ovulation” takes place, the SA will be
redelivered to the blood and the extra
consumption of SA will be stopped in this phase.
The fluctuation in SA concentration in the blood
will be reflected in saliva. The results of the
present study disagreed with Calamera et al. (18)
Vol. 24(2), 2012
who reported a peak in salivary SA concentrations
in the pre-ovulatory phase and Alagendran et al.
study (1) who reported a peak in salivary SA
concentrations in the ovulatory phase.
Glycosaminoglycans
In the present study, GAG showed a comparable
concentration
in
the
ovulatory
phase
(0.412±0.175) ng/ml, to that of the control groups
((0.452±0.279) for the pre-pubertal group and
(0.445±0.041) for the postmenopausal group) with
the peak GAG concentration in the post ovulatory
phase. These results are so far away from
Alagendran et al. (1) study, in which, the GAG
content showed a distinct peak at ovulation.
The present results are also a disagreement with
Giampiero et al. (19), who stated that in the women
with ovulatory cycles, plasma GAG levels
differed significantly during menstrual cycle, with
increased values at the periovulatory phase (3.5
ug/ml) with respect to the menstrual phase.
Another study did not find consistent variations
during the normal menstrual cycle (20). In contrast,
a significant variation in the urinary GAG
concentration during ovulation was reported by
Carranco et al. (21), this peak of maximal GAGs
concentration (106.7 ± 46.2 micrograms/mL in
urine) was noticed during the ovulatory phase.
In this research, the peak GAG concentration is in
the post ovulatory phase (0.558± 0.218)ng/ml, this
could be due to the release of follicular fluid with
its GAG content after rupture of the follicle to the
blood stream which will be reflected in saliva.
Another possible cause to the reduced GAG
concentration in the first half of the menstrual
cycle, and its increase in the post-ovulatory phase
is that heparenase enzyme (HSPE) is transiently
induced by luteinizing hormone during the
ovulatory process and may be down-regulated by
the increasing progesterone levels in the luteal
phase (22).
On the basis of the results arrived at, the study
concluded that SA and GAGs were probably
brought under the influence of cyclic variation of
ovarian hormones. There are remarkable cyclic
variations in sialic acid and GAGs during the
menstrual cycle but in conclusion, GAGs and
sialic acid cannot be used for the precise
prediction of ovulation.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
REFERENCES
1. Alagendran S, Archunan G, Velayutha S Prabhu,
Enrique B, Orozco A and Rosalinda Guevara Guzman.
Biochemical evaluation in human saliva with special
reference to ovulation detection. Indian J dental Res
2010; 21(2):165-8.
2. Khaustova S, Shkurnikov M, Tonevitsky E,
Artyushenko V, Tonevitsky A. Noninvasive
Oral Diagnosis
19.
68
Ovulation detection
biochemical monitoring of physiological stress by
Fourier transform infrared saliva spectroscopy.
Analyst 2010; 135: 3183-92.
Galef BG Jr, Smith MA. Susceptibility of artificially
reared rat pups to social influences on food choice.
Dev Psychobiol 1994; 27: 85-92.
Rameshkumar K. Chemical characterization of Bovine
(Bos Taurus) Urine with special reference to
reproductive behavior. Ph.D Thesis. Tiruchirappalli,
Tamil Nadu, India: Bharathidasan Uzniversity; 2000.
Rudney JD. Does variability in salivary protein
concentrations influence oral microbial ecology and
oral health? Crit Rev Oral Biol Med 1995; 6: 343-367.
Ogasawara Y, Namai T, Yoshino F, Lee MC, Ishii K.
Sialic acid is an essential moiety of mucin as a
hydroxyl radical scavenger. FEBS Lett 2007; 581:
2473-77.
Bishop JR, Schuksz M, Esko JD. Heparan sulphate
proteoglycans fine-tune mammalian physiology.
Nature 2007; 446: 1030-7.
Richards JS.Ovulation: new factors that prepare the
oocyte for fertilization. Mol Cell Endocrinol 2005;
234(1-2): 75-9.
Navazesh M. Methods for collecting saliva. Ann N Y
Acad Sci 1993; 20: 72-7.
Tram T H, J C Brand Miller, Y McNeil, P McVeagh.
Sialic acid content of infant saliva: comparison of
breast fed with formula fed infants Archives of
Disease in Childhood 1997; 77: 315-8.
Salvolini E, Mazanti L, Martarelli D, Di Giorgio.
Changes in the composition of human unstimulated
whole saliva with age. Aging (Milano) 1999;
11(2):119-22.
Dezan CC, Nicolau J, Souza DN, Walter LRF. Flow
rate, amylase activity, and protein and sialic acid
concentrations of saliva from children aged 18, 30 and
42 months attending a baby clinic. Archives of Oral
Biology 2002; 47(6): 423-7.
Narhi Timo O, Tenovuo J, Ainamo A, Vilja
P.Antimicrobial factors, sialic acid and protein
concentration in whole saliva of the elderly. J Dent
Res 1994; 102: 120-5.
Carlborg L, Johansson ED, Gemzell C. Sialic acid
content and sperm penetration of cervical mucus in
relation to total urinary oestrogen excretion and
plasma progesterone levels in ovulatory women. Acta
Endocrinol (Copenh) 1969; 62: 721-31.
Oster G, Yang SL. Cyclic variation of sialic acid
content in saliva. Am J Obstet Gynecol 1972; 15: 1903.
Moghissi KS, Syner FN. Cyclic changes in the amount
and sialic acid of cervical mucus. Int J Fertil 1976; 21:
246-50.
Rudong Xing, Yuzhuo Zhang, Zhisan Wang, Ruimei
Chen. Serum sialic acid level in patients with oral and
maxillofacial malignancy. J Oral maxillofacial
Surgery 1991; 49: 843-7.
Calamera JC, Vilar O, Nicholson R. Changes in sialic
acid concentration in human saliva during the
menstrual cycle. Int J Fertil 1986; 31(1):43-5.
Giampiero Capobianco, De Muro Pierina, Cherchi
Gian Mario, Formato Marilena, Lepedda Antonio
Junior, Cigliano Antonio et al. Plasma levels of Creactive protein, leptin and glycosaminoglycans during
spontaneous menstrual cycle: differences between
Vol. 24(2), 2012
ovulatory and anovulatory cycles. Educus 2010;
282(2): 207-13.
20. Erickson DR, Ordille S, Martin A, Bhavanandan VP.
Urinary chondroitin sulfates, heparan sulfate and total
sulfated glycosaminoglycans in interstitial cystitis. J
Urol 1997; 157: 61-4
21. Carranco A, Reyes R, Huacuja L, Guzmαn A, Delgado
NM. Human urinary glycosaminoglycans as accurate
Ovulation detection
method for ovulation detection. Int J Fertil 1992; 37:
209-13.
22. Eyal Klipper, Ehud Tatz, Tatiana Kisliouk, Israel
Vlodavsky, Uzi Moallem, Dieter Schams,Yaniv
Lavon, David Wolfenson, and Rina Meidan. Induction
of Heparanase in Bovine Granulosa Cells by
Luteinizing Hormone: Possible Role during the
Ovulatory Process. Endocrinology 2009; 150: 413-21.
Figure 1: Saliva SA level in Control and Experimental Groups (mean± SD)
Figure 2: Saliva GAGs level in control and experimental groups (mean± SD)
No significant correlation was found between SA and GAGs in all the study groups.
Oral Diagnosis
69
Vol. 24(2), 2012
Temporomandibular disorders
Temporomandibular disorders in association with stress
among students of sixth grade preparatory and students of
fifth year high schools
Toka T. Alnesary, B.D.S. (1)
Rafil H. Rasheed, B.D.S., M.Sc. (2)
ABSTRACT
Background: A close relationship had been reported between depression, anxiety and many disease symptoms or
disorders. This is true for temporomandibular disorders which is a collective term embracing a number of clinical
problems that involve the masticatory musculatures, temporomandibular joint and associated structures, or both. This
study designed to evaluate the association of stress with temporomandibular disorders among sixth grade
preparatory students and students of fifth year of secondary school.
Subjects, materials and methods: The sample's size of 404 students of sixth grade preparatory study (154males and
250 females) and 360 (168males and 192females) of fifth year of secondary schools. Firstly all the students subjected
for stress questionnaire, secondly the stressful students subjected to different combination of clinical and
questionnaire measures according to the research diagnostic criteria of temporomandibular disorders (axis I) which
have standardized series of diagnostic tests based on clinical signs and symptoms. Data are analyzed by using Z-test
and chi-square.
Results: The results obtained from this study showed that no significant differences between classes in the percentage
of stressful students with temporomandibular disorders according to the clinical examination but in both classes,
females' students showed higher percentage of temporomandibular disorders than males of same class. Bruxism and
nail biting were significantly higher among students of sixth grade.
Conclusions: This study revealed that stress of studying at sixth grade has no effect on temporomandibular disorders
prevalence.
Keywords: Stress, temporomandibular disorders, myofascial. (J Bagh Coll Dentistry 2012;24(2):70-74).
INTRODUCTION
Research findings have supported a
relationship between anxiety, muscular tension,
and TMD symptoms, the psychological status
assessment
showed that 39.8% of patients
with TMD experienced moderate to severe
depression, and 47.6% had moderate to severe
nonspecific
physical
symptom
scores
(somatization) 9.
The importance of psychological factors in the
etiology
of
TMD
has
usually
been
emphasized; they are believed to predispose the
individual to chronicity 10.
Temporomandibular disorders are often
associated with somatic and psychological
complaints, including fatigue; sleep disturbances,
anxiety, and depression 9, 11. Thus, considering
that stress is associated with psychological
disturbances such as anxiety and depression 12.
Temporomandibular joint (TMJ) should not be
isolated or excluded from being associated with
other joints disorders but fortunately the
temporomandibular disorders (TMDs) could be an
early exploration to other joint disorders1
Temporomandibular disorders are a collection
of disorders involving the temporomandibular
joint, the soft tissue structures within the joint,
and the muscles of mastication 2.
The etiology of these disorders is
multidimensional. Biomechanical, neuromuscular,
biopsychosocial, and neurobiological factors may
contribute to TMDs 3. These factors are initiating
and aggravating (parafunctions, hormonal, or
psychosocial factors) to emphasize their role in
the progression of TMD 4. Some studies revealed
that occlusal factors were only weakly associated
with TMD signs and symptoms 5, 6. Moreover,
there are people classified as bruxers, who did not
present history of pain in masticatory muscles 7, 8.
There is currently considerable evidence that
psychological factors are of importance in the
understanding of TMD.
This study was carried out in randomly
selected secondary schools of Baghdad city for
evaluation the association of stress with TMDs in
students according to the research diagnostic
criteria of TMD (RDC/TMD axis I).
The sample's size of 404 students of sixth
grade preparatory study (154 males and 250
females) and 360 (168 males and 192 females) of
fifth year of secondary schools.
(1) M.Sc. Oral Medicine, Ministry of Health, Iraq.
(2) Professor, Dean of College of Dentistry, University of AlAnbar, Iraq
Oral Diagnosis
70
Vol. 24(2), 2012
The patients were asked about any bad oral
habits with observation their evidences.
Subjects gave their informed consent and the
local ethical committee approval.
The students subjected for stress questionnaire
which consist of 20 questions a score of 7 or more
is considered positive for a potential psychiatric
problem. Then the stressful students subjected to
different combination of questionnaire and
clinical measures according to RDC/TMD (Axis
I).
The stressful students whom subjected to
clinical examination had no history of head injury
and without orthodontic treatment, dental pain,
muscle tenderness due to systemic diseases as
fibromyalgia, neuralgia or local infection and had
no more than 2 missing posterior teeth.
The stressful students who had pain in the
face, jaw, temple, priauricular or in the ear and
headaches or migraine or pain that limit these
activities: chewing, exercising, eating hard or soft
food or drinking, smiling, oral hygiene, yawning
and talking and those who had clicking, bruxism
and oral habit were asked about: the pain history
with conformation of pain location plus palpation
of masticatory muscle sites, results in report of
familiar pain13, and asked about jaw locking or
catching that interfere with eating
The students with positive answer subjected to
clinical examination, these include ear
examination,
cervical
examination,
and
determination of masticatory muscles pain during
active mouth opening (un-assisted mouth
opening) and passive mouth opening (assisted
mouth opening).This accomplish by Palpation the
TMJ (lateral pole) during opening and closing
three times at least to detection the joint sound.
Then determination of masticatory muscles and
TMJ pain during excursive movement of
mandible, with determination of joint sound on
excursive movement of mandible by stethoscope
placed on lateral pole of TMJ 14
Tenderness of TMJs needs to be palpated in
three locations. Tenderness in one of these
locations is not necessarily associated with
tenderness in another. Pain or tenderness can
occur in static position or during opening and
closing the mouth. palpation of the first location
by asking the patient to open approximately 20
mm and palpating the condyle’s lateral pole, then
by asking the patient to open as wide as possible
while palpating the depth of depression behind the
condyle with fingertip, finally with the finger in
the depression and the mouth open wide, by
pulling forward to load the posterior aspect of the
condyle via external auditory meatus using the
small finger.
Oral Diagnosis
RESULTS
There were significant differences between
classes in percentage of stressful students by selfreport stress,. In this study from all selected males
of fifth year there were 21 (12.5%) stressful
students and from selected females of fifth year
there were 117(60.9%) stressful students, so the
total number of stressful students in the fifth year
of secondary study was 138 (38.3%) from 360
students were subjected to self report
questionnaire, while in the six grade of secondary
study the percentage of stressful students were
higher than those in fifth year as follow: stressful
males were 62(40.3%) and 214 (85.6%) stressful
females, so the total number of stressful students
in sixth grade was 276 (68.3%) These findings
were listed in table (1).
But there were no significant differences
between classes in percentage of stressful students
had TMDs according to the clinical examination,
In this study from all selected students of fifth
year there were 10 (5.9%) males and 45(23.4%)
females had TMD by clinical examination, so the
total number of the stressful students with TMDs
by clinical examination in the fifth year of
secondary study was 55 (15.2%) which was less
than students in the six grade where TMDs
showed 63(15.5%) which divided into 12 (7.7%)
males and 51 (20.4%) females, and these findings
were listed in table (2).
The number of students in the fifth year who
had myofascial pain (and some of them had MFP
in combination with other TMDs) was (52), which
was more than those in sixth grade (48) and the
differences were significant, while the disc
displacement with reduction was (6), the disc
displacement without reduction was (6) and
arthralgia also was (6) presented in less
numbering the students of fifth year in
comparison to those of sixth grade (8,15,12)
respectively but the differences were not
significant.
It had been found that percentage of sixth
grade students with deflection (57.1%) was higher
than that in the fifth class students (50.9%), and
the percentage of sixth grade students with nail
biting (34.9%) was higher than that in the fifth
class students (9.1%) with significant differences.
DISCUSSION
This study revealed that most of students in the
secondary school were under stress and the
differences were highly significant (P value =
71
Vol. 24(2), 2012
is in agreement with other reports in the literature
28, 29
.It has been stated that these sex differences
could probably be explained by mental factors i.e.
young females seem to present a lower pain
threshold 28. Kuttilla et al., found that females
showed more signs and symptoms of TMD, and it
seems to be explainable by their higher stress. The
higher prevalence of TMD in females than in
males has been attributed to an interaction of a
variety of factors ranging from biological and
hormonal factors to psychological and social ones.
In this study the students who were recorded
with myofascial pain more than students with
other TMDs even those students with MFP alone
or in combination with other TMDs. Lobbezoo et
al., (2004) revealed that between 50% and 70% of
all patients with TMDs reported masticatory
muscle pain,
Deflection (57.1%, 50.9%) and midline
deviation (58.7%; 61.8%) were reported in both
sixth class and fifth class respectively, which were
higher than that observed by other study (Feteih,
2006). Several studies failed to find strong
evidence to support the theory that occlusion
plays a role in the etiology of TMD, particularly
as the sole cause or the dominant factor 32, 33.
While Gesch et al., (2004) reported a weak
association between malocclusion and the
functional and clinical parameters of occlusion as
well as subjective TMD.
Oral habits (nail biting) was also reported in
this study and showed higher percentage among
students of sixth (34.9%) than students in the fifth
class (9.09%) with significant difference. Other
study reported lower percentage than that of
students in sixth class 20.
The higher frequency of nail biting that had
been recorded at clinical examination may explain
the higher percentage of students at sixth class
with disc displacement without reduction,
arthralgia and disc displacement with reduction.
There is currently considerable evidence that
psychological factors are of importance in the
understanding of TMD. The issue of whether
psychological factors cause TMD or reflect the
impact of TMD on the person remains unknown,
although there is strong evidence that some
patients with TMD are more anxious and/or
depressed compared with asymptomatic controls.
Research findings have supported a relationship
between anxiety, muscular tension, and TMD
symptoms 35.
0.001) between fifth (38.3%) and sixth grades
(68.3%). Yusoff et al., 201115 in previous study
found that the prevalence of distressed secondary
school students in Malaysia was 32.8%. Other
previous studies reported that over one-third of
adolescents were under stress 16, 17. Many of these
emotional disturbances seem to be caused by
school-related stress such as inappropriate
workloads or assignments, examinations, falling
behind compared to others and inappropriate
treatment by teachers 16 Several authors have
observed that the prevalence of psychological
distress is higher among students than among
working nonstudent populations of the same sex
and age 18
By clinical examination it had been shown that
the prevalence of TMDs in stressful students of
fifth and sixth year of secondary study was nearly
equal (15.2%, 15.5%), although the percentage of
stressful students in sixth grade was significantly
higher. This percentage was lower than that
observed in another studies 19, 20, 21 and showed
agreement with similar result reported by 22, 23.The
large frequency ranges for signs and symptoms of
TMD previously described in reviews are
apparently based on very different samples (e.g.
random , non-random, different ages, age ranges,
sample size, ratio of gender distribution) and
different examination methods (e.g. kind of
variable, method of data collection) 24.
The role of stress and personality in the
etiology of the temporomandibular pain
dysfunction syndrome has undergone extensive
scrutiny. There is considerable evidence that
psychological and psychosocial factors are of
importance in the understanding of TMD as with
other chronic pain disorders 25 but there is less
evidence that these factors are etiologic. Even
though studies have indicated the role of stress in
the etiology of TMD, the issue of whether
psychological factors cause TMD or reflect the
impact o TMD on the person remains unknown,
due largely to the absence of longitudinal
incidence studies designed to test the relationship
of the onset of TMD pain to the onset of
psychological and psychosocial factors. Several
studies have assessed the relationship between
TMD and stress, these studies have had
shortcomings, e.g., assessment of acute stress,
limited sample size, nonstandardzed examination,
no controls12, 26, 27
Although some reports noted no sex
differences in the prevalence of TMD 20, 23, this
has not been the case for some of the signs and
symptoms in the present study. Generally females
have more signs and symptoms than males. This
Oral Diagnosis
72
Vol. 24(2), 2012
Government Secondary School: Initial Findings.
ASEAN J Psychiatry 2010; 11(2).
17. Khalid SAG. Depression, anxiety and stress among
Saudi adolescent school boys. JR Prom Health 2007;
127(1): 33-7.
18. Dyrbye LN, Thomas MR, Shanafelt TD. Systematic
review of depression, anxiety, and other indicators of
psychological distress among U.S. and Canadian
medical students. Acad Med 2006; 81:354–73.
19. Farsi NM: Symptoms and signs of temporomandibular
disorders and oral parafunctions among Saudi
children. J Oral Rehabil 2003, 30:1200-8.
20. Feteih
RM.
Signs
and
symptoms
of
temporomandibular disorders and oral parafunctions in
urban Saudi arabian adolescents: a research report.
Head and face medicine 2006; 5:567-71.
21. Thilander B, Rubio G, Pena L, Mayorga C Prevalence
of temporomandibular dysfunction and its association
with malocclusion in children and adolescents: an
epidemiologic study related to specified stages of
dental development. Angle Orthod 2002; 72:146-54.
22. Farsi N. Temporomandibular dysfunction and
emotional status of 6–14 years old Saudi female
children. Saudi Den J 1999; 11:114-9.
23. Deng Y, Fu MK, Hagg U. Prevalence of
temporomandibular joint dysfunction (TMJD) in
Chinese children and adolescents. A cross-sectional
epidemiological study. Eur J Orthod 1995; 17:305-9.
24. Gesch D, Bernhardt O, Alte D, Schwahn C, Kocher T,
John U, Hensel E. Prevalence of signs and symptoms
of temporomandibular disorders in an urban and rural
German population: Results of a population-based
Study of Health in Pomerania. Quintessence Int 2004;
35:143-50.
25. Neill Mc C. Management of temporomandibular
disorders: concepts and controversies. J Prosthet Dent
1997; 77:510-22.
26. Glaros AG. Temporomandibular disordes and facial
pain: a psychophysiological perceptive. Appl
psychophysiol Biofeedback 2008; 33: 161-71.
27. Fricton J. Myogenous temporomandibulae disorded:
diagnostic and management consideration. Dent Clin
North Am 2007; 51:61-83.
28. Dao TT, LeResche L. Gender differences in pain. J
Orofac Pain 2000; 14:169-84.
29. Farsi NM: Symptoms and signs of temporomandibular
disorders and oral parafunctions among Saudi
children. J Oral Rehabil 2003; 30:1200-8.
30. Kuttila M, Niemi PM, Kuttila S, Alanen P, Le Bell Y
.TMD treatment need in relation to age, gender, stress,
and diagnostic subgroup. J Orofac Pain 1998; 12:67–
74
31. Lobbezoo MD, Shafer D, Napolitano C. Momentary
mood and coping processes in TMD pain. Health
Psychology 2004; 23: 354– 62.
32. Boever De JA, Carlsson GE, Klineberg IJ. Need for
occlusal therapy and prosthodontic treatment in the
management of temporomandibular disorders: Part I,
Occlusal interferences and occlusal adjustment. J Oral
Rehabil 2000; 27:367-79.
33. Pullinger AG, Seligman DA. Quantification and
validation of predictive values of occlusal variables in
temporomandibular disorders using a multifactorial
analysis. J Prosthet Dent 2000; 83:66-75.
34. Gesch D, Bernhardt O, Alte D, Schwahn C, Kocher T,
John U, Hensel E. Prevalence of signs and symptoms
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1. Martin S, Michael Glick, Jonathan A. Oral medicine,
Diagnosis and treatment. 11th ed. BC Decker Inc;
2008. p.243.
2. Leeuw De R. Internal derangement of the
temporomandibular joint. Oral Maxillofac Surg Clin
North Am 2008; 20:159-68.
3. Suvinen TI, Reade PC, Hanes KR, Könönen M,
Kemppainen P. Temporomandibular disorder subtypes
according to selfreported physical and psychosocial
variables in female patients:a reevaluation. J Oral
Rehabil 2005; 32:166-73.
4. Neill Mc C. Management of temporomandibular
disorders: concepts and controversies. J Prosthet Dent
1997; 77: 510-22.
5. Mohlin BO, Derweduwen K, Pilley R, Kingdon A,
Shaw WC, Kenealy P Malocclusion and
temporomandibular disorder: a comparison of
adolescents with moderate to severe dysfunction with
those
without
signs
and
symptoms
of
temporomandibular disorder and their further
development to 30 years of age. Angle Orthod 2004;
74:319–27.
6. Magnusson T, Egermarki I, Carlsson GE A
prospective investigation over two decades on signs
and symptoms of temporomandibular disorders and
associated variables. A final summary. Acta Odontol
Scand 2005; 63:99–109.
7. Lavigne GJ, Kato T, Kolta A, Sessle BJ.
Neurobiological mechanisms involved in sleep
bruxism. Crit Rev Oral Biol Med 2003; 14:30–46
8. Fujii T, Torisu T, Nakamura S. A change of occlusal
conditions after splint therapy for bruxers with and
without pain in the masticatory muscles. Cranio 2005;
23:113–8.
9. Yap AU, Dworkin SF, Chua EK, List T, Tan KB, Tan
HH. Prevalence of temporomandibular disorder
subtypes, psychologic distress, and psychosocial
dysfunction in Asian patients. J Orofac Pain 2003;
17:21-8.
10. Rollman GB, Gillespie JM. The role of
psychophysiological factores in temporonandibular
disorders. Curr Rev Pain 2000; 4:71-81.
11. Bonjardim LR, Gaviao MB, Pereira LJ, Castelo PM.
Anxiety and depression in adolescents and their
relationship with signs and symptoms of
temporomandibular disorders. Int J Prosthodont 2005;
18:347-52.
12. Gameiro GH, da Silva Andrade A, Nouer DF, Ferraz
de Arrude Veiga MC. How many stressful experiences
contribute to the development of temporomandibular
disorders? Clin Oral Invest 2006; 10: 261-8.
13. Okeson JP. Management of temporomandibular
disorders and occlusion. 6th ed. 2008; pp. 468.
14. Okeson JP. Assessment of orofacial pain disorders. In
Okeson J, editor: Orofacial pain: guideline for
assessment, diagnosis, and treatment, Chicago, 1996,
Quintessence, pp32-4.
15. Yusoff MSB, Yee LY, Wei LH, Meng LH, Bin LX,
Siong TC, Abdul Rahim AF. A study on stress,
stressors and coping strategies among Malaysian
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16. Yusoff MSB. Stress, Stressors & Coping Strategies
among Secondary School Students in a Malaysian
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Vol. 24(2), 2012
of temporomandibular disorders in an urban and rural
German population: Results of a population-based
Study of Health in Pomerania. Quintessence Int 2004;
35:143-50.
35. Fricton JR. Masticatory myofascial pain: an
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Group Int Rech Sci Stomatol Odontol 1999; 41:14–25.
Table 1: The differences between classes in the percentage of stressful students by self report
stress
Sex
Male
Female
Total
P value
Total
L68
192
360
5th secondary
No.with stress % withy stress total
21
12.5
154
117
60.9
250
138
38.3
404
0.0001*
6th secondary
No.with stress % withy stress
62
40.3
214
85.6
276
68.3
*Significant using Z-test at 0.05 level of significance
Table 2: The differences between classes in percentage of students had TMDs according to
clinical examination
Sex
Male
Female
Total
P
value
total
168
192
360
5th secondary
No. with
% with TMD by clinical
TMD
examination
10
5.9
45
23.4
55
15.2
Total
154
250
404
6th secondary
No. with
% with TMD by clinical
TMD
examination
12
7.7
51
20.4
63
15.5
0.336
*Significant using Z-test at 0.05 level of significance
Oral Diagnosis
74
Vol. 24(2), 2012
Histological evaluation
Histological evaluation of osseointegration around
titanium implants in thyroidectomized rabbits
(experimental study).
Zaid M. Ali, B.D.S., M.Sc. (1)
Nada M. H. Al-Ghaban, B.D.S., MSc., Ph.D. (2)
ABSTRACT
Background: Thyroid hormones are essential for linear growth and peak bone mass acquisition. Hypothyroidism
occurs when the thyroid gland produces less than the normal amount of thyroid hormones. The present study was
carried out to evaluate the effect of hypothyroidism on osseointegration around the titanium implants screwed in
rabbit's tibia.
Materials and methods :Fifty four machined surface Iraqi implants were inserted in 27 male rabbits (2implants in each
rabbit's tibia ).Eighteen of these rabbits were subjected to near total thyroidectomy to induce hypothyroidism three
weeks before implantation surgery. While the remaining 9 rabbits were remain as a control group. Blood sample was
taken from each animal at the beginning of this study in order to find the normal range of T3,T4,and TSH .And another
blood sample was taken for experimental groups to find the levels of T3,T4,and TSH three weeks after thyroidectomy
in order to assess the hypothyroidism status .After 2, 4, 6 weeks after implant surgery (6rabbits from experimental
group and 3rabbits from the control group) were sacrificed. In the day of scarification, one of the screws was
unscrewed with a torque meter, and the peak torque required to shear off the implant was recorded. Then the
decalcified sections of the bone around the implants were studied histologically and histomorphometrically .The eye
piece reticule was used for morphometrical studies, which were includes: number of osteocytes, number of
osteoblasts, thickness and number of bone trabeculae, and thread width
Results:The results showed that hypothyroid rabbits had delay in osseointegration, bone formation and maturation
around implants in almost all rabbits in experimental groups. While the rabbits in the control groups showed
improvement in osseointegration around titanium implant. Removal torque test illustrated higher torque test value in
control animals than in experimental one. Moreover, there were increases in torque test values in both groups with
time. Biochemical serum analysis revealed a decrease in T3, T4, and increase TSH levels in experimental animals.
Conclusion: It can be concluded that there were low bone quality with a delay in bone healing around titanium
implants in hypothyroidied rabbits compared with healthy one.
Key words: Hypothyroidism, Titanium implants, Rabbits tibia, Osseointegration. (J Bagh Coll Dentistry 2012;24(2):7579).
INTRODUCTION
Dental implant treatment has revolutionized oral
rehabilitation in partially and fully edentulous
patients. When the concept of osseointegration
was introduced in relation to titanium endosseous
implants (1).It became possible to achieve high
success rates in association with this treatment
modality, and multiple investigations have
demonstrated an excellent long-term prognosis.
The
achievement
and
maintenance
of
osseointegration are highly dependent on bone
quality and quantity. The systemic conditions may
be correlated with impaired bone healing around
titanium implants, especially in metabolic bone
diseases such as osteoporosis, diabetes mellitus,
and hypothyroidism (2).
Bone is a highly metabolically active tissue in
which the processes of osteoblastic bone
formation (anabolic activity) and osteoclastic
resorption (catabolic activity) are continuous
throughout life.
Therefore, the capacity of bone tissue to respond
to injuries such as fracture or implant placement is
associated with several mechanisms and may be
affected by different conditions (3).
Thyroid hormones are the major regulators of
bone
metabolism
and
development.
Hypothyroidism is a condition in which the
thyroid gland does not make enough thyroid
hormone (A deficiency of thyroid hormone) to
meet the body’s needs. Without enough thyroid
hormone, many of the body’s functions slow
down. The scientific consensus is that untreated
hypothyroidism causes an abnormally decreased
bone density coupled with poor bone quality, and
have been linked to altered osteoblast and
osteoclast activity, leading to an imbalance in
bone turnover (4).
Although thyroid dysfunctions may affect bone
metabolism via their effect on thyroid hormone
levels that influence bone turnover (5) there is a
lack of information regarding the effect of
changes in T3 and T4 serum levels on bone
healing around titanium implants. Thus, the
objective of this study was to clarify the
establishment
and
maintenance
of
(1) M.Sc.student, Department of Oral Histology and Biology,
College of Dentistry, University of Baghdad
(2) Ass.Professor, Department of Oral Histology and Biology,
Oral Diagnosis
75
Vol. 24(2), 2012
osseointegration in thyroidectomy
hypothyroidism in rabbit’s tibia.
–induced
Histomorphometrical analysis
Trabicular thickness and number
The results showed that there were
significant(P≤0.01) decrease in the trabecular
bone thickness in experimental group compared
to their control in the 6th weeks interval only
(Table. 2).While there were no significant
differences in the trabecular number between the
experimental and control groups in all healing
periods (Table .3).
Twenty seven male adult New Zealand white
rabbits aged from 9 to 12 months were used as
animal model in this study. Their weights ranged
between 1.5 to 2.5 kg .The animals were kept
under the supervision from staff of the animal’s
house of the College of Veterinary medicine. The
animals of this study were divided into two
groups, experimental group (18 rabbits) and
control group (9 rabbits) .The animals of
experimental group were subjected to near total
thyroidectomy to induce hypothyroidism, three
weeks before implant operation.
The levels of thyroid hormones (T3, T4, and
TSH) were detected before and three weeks after
the thyroidectomy operation (6).
After 2, 4, 6 weeks intervals, the most distal screw
was exposed and unscrewed with a torque meter,
and the peak torque required to shear off the
implant was recorded.
Then the decalcified sections of the boneimplants block were stained with (H&E) and VanGieson's stains for
histological and
histomorphometrical studies, which were
includes: number of osteocytes, number of
osteoblasts, thickness and number of bone
trabeculae, and thread width
The statistical analyses were calculated by SPSS
(personal computer) (7). In all multiple
comparisons significant p-value was at (p< 0.05).
Table 2: Trabecular bone thickness (µm)
group
H.P
2weeks
4weeks
6weeks
H.P
2weeks
4weeks
6weeks
9.83±0.50
18.83±1.17
23.44±0.78
4.77±1.16
10.0±0.38
14.0±1.4
P≤0.01*
P≤0.01*
P≤0.01*
Oral Diagnosis
4.75±0.76
10.31±1.29
14.06±1.07
3.75±0.72
9.16±0.42
9.375±0.81
N.S
N.S
p≤0.01*
control
experimental
P- value
2.75±0.5
5.33±0.76
3.40±0.79
2.60±0.05
4.83±0.61
3.0±0.91
N.S
N.S
N.S
Table 4: Osteocytes number in different
groups
group
H.P
2weeks
4weeks
6weeks
group
H.P
2weeks
4weeks
6weeks
P- value
Number of osteocytes
The results denote that there was a highly
significant(P≤0.01)decrease in the number of
osteocyts in 2 weeks of the experimental group
but there was a significant(P≤0.05) increase in
the number of osteocyte in the period of six weeks
in the experimental group compared with the
control group (Table .4) .
Table 1: Torque test values of different
groups
P- value
experimental
group
RESULTS
experimental
control
Table 3: Trabecular number in different
groups
Torque removal test
The lowest mean torque values for both groups
were recorded in 2 weeks while the highest mean
value was detected in 6 weeks. Also there was a
significant (P≤0.01) decrease in the torque values
of the experimental groups compared with their
controls for healing period (Table. 1).
control
control
experimental
P- value
27.33±1.76
31.67±3.3
21.67±0.9
16.33±2.60
28.60±2.1
26.75±2.21
P≤0.01**
N.S
P≤0.05*
Number of osteoblast:
The results showed that there is there was a
highly significant decrease (P≤0.01) in the
number of osteoblasts in the experimental groups
as compared with their controls in all healing
periods (Table. 5).
76
Vol. 24(2), 2012
Table 5: Number of osteoblast in study
groups
group
H.P
2weeks
4weeks
6weeks
control
experiment
al
P- value
29.5±1.56
25.66±1.04
20.33±1.26
26.33±0.72
22.66±1.53
16.33±1.53
P≤0.01*
P≤0.01*
P≤0.01*
Figure 2: Experimental group at 2weeks
duration showing newly formed bone
trabecule(B.T) (Van-gieson's stain X 200).
Thread width
The results indicate that there was a significant
reduction in thread width of experimental animals
of 4 and 6 weeks healing periods when compared
with their controls (Table .6 ) .
Table 6: Thread width in study groups (µm).
group
H.P
2weeks
4weeks
6weeks
control
experimental
P- value
18.125±2.13
21.875±1.88
26.5±1.27
17.5±1.44
18.75±7.2
20.625±0.63
N.S
P≤0.05*
P≤0.01**
Figure 3: Control group at 4weeks duration
showing osteoblast (OB),
osteocytes(OS).(H&E X200)
Histological findings:
The histological findings in 2-weeks interval
showed large and numerous bone trabeculae in
control group, while there was few and small
bone trabeculae in the thread of experimental
group (Figures 1,2). The histological appearance
of 4-weeks interval revealed immature bone
which almost fill the whole thread in control
group (Figure.3), while in the experimental group
of the same period showed that there was fibrous
connective tissue in near the implant surface with
immature bone (Figure.4,5).
The histological picture of 6-weeks interval of the
control group illustrated mature bone with
numerous incremental lines that fill the whole
thread of cortical bone region(Figure 6), and
thick bone trabeculae near the implant surface in
the bone marrow region (Figure 7). While the
picture of experimental group of the same period
revealed still immature bone that fill the whole
thread in the compact bone region (Figure 8).
Figure 4: Experimental group in 4weeks
duration Showing preosteocytes
(POS),osteoclast(OC) (H&E X200).
Figure 5: Experimental group at 4weeks
duration showing immature compact bone
with large size osteocytes (OS),
preosteocytes(POS) (Van-gieson's stain
X400).
showing osteocytes(OS) inside bone
trabecule (Van-gieson's stain X200).
Oral Diagnosis
77
Vol. 24(2), 2012
Histomorphometrical analysis:
T3 regulates the differentiation of osteoblasts,
by increasing the expression of many genes of the
osteoblastic
phenotype
like
osteocalcin,
osteoprotegerin ,and this may explain the
decreased number of osteoblasts in the
experimental groups in all the study periods
compared with their controls (10).
Because of ostecytes are derived from
osteoblasts(11) , the effect of thyroid hormones
reduction on osteoblasts can be seen in osteocyte
numbers in the experimental groups. Also this
study showed decrease in trabecular thickness and
numbers in the hypothyroid animals than controls
.This most probably due to low bone turnover in
hypothyroisim which affect both bone resorption
and bone formation and cause reduction in osteiod
apposition (12).
Hypothyroidism resulted in less newly formed
bone within the implant threads and this may
explain the reduction in thread width of new bone
formed around the implant screwed in the
experimental animals. This finding agree with
Wilkins et al(13).
.Revealing mature bone thread with
numerous incremental lines (arrows) (H&E
X400).
Figure 7: Microphotograph of the control
group at 6weeks duration revealing bone
trabecule in bone marrow region Outline the
thread (Van-gieson's stain X200).
Histological and histochemical findings:
The histological finding of control rabbits of
2weeks interval showed newly formed woven
bone with new bone trabeculae .While the
hypothyroid rabbits showed generalized delay in
bone remodeling in comparison with control
rabbits. This finding may be due to the fewer
number of active osteoblasts in the hypothyroid
rabbits which are responsible for the formation of
new bone matrix. This finding agrees with
Williams (14)
The histological picture of control animals at
4weeks duration manifested dense newly formed
bone rather than trabecular appearances, and
osteocytes were trying to get concentric
arrangement around haversian canal. While in
experimental group the newly formed bone had a
trabecular appearance. Osteocytes still irregularly
arranged. Osteoclasts and reversal lines were
widely seen in the newly formed bone which may
gave the indication of continuous bone
remodeling. These differences might be attributed
to the decrease in the secretion of T3 and T4 in
hypothyroid animals which cause delay in bone
formation and maturation .This result correlate
with previous study done by Williams (15).
The histological and histochemical findings of the
control animals at 6weeks duration showed almost
mature newly formed bone threads .It had the
same mature appearance of the original bone
.while in experimental animals of this period, the
newly formed bone in general was not completely
Figure 8: Experimental group at 6 weeks
showing immature bone with large size
osteocytes (arrows) (H&E X200).
DISCUSSION
This study showed increase in removal torque
value over time for both experimental and control
groups. It has been suggested that this increase
depends on increasing bone-to-implant contact
with time as a result of progressive bone
formation and maturation around implant during
healing, which substantially improved the
mechanical capacity (8).On the other hand, the
increased removal torque values for control
animals comparing with hypothyroid animals in
all healing periods indicated that hypothyroidism
may affect the bone formation and maturation
around the implants negatively (9).
Oral Diagnosis
78
Vol. 24(2), 2012
11. Salman S, Aral F, Boztepe H, Colak N, Omer B,
Tanakol R, Alagol F& Uzum K. Evaluation of the
association between bone turnover markers and
OPG/sRANK-L levels in relation with the changes of
thyroid function in women with thyroid cancer.
European Congress of Endocrinology .Endocrine
Abstracts 2009; 20:P238.
12. Feitosa DS, Bezerra BD, Ambrosano GM, Nociti Jr
FH, Casati MZ , Sallum EA,Toledo SD. Thyroid
Hormones May Influence Cortical Bone Healing
Around Titanium Implants. J Periodontal Res 2008 ;
79:7:881-887.
13. Wilkins SB, Clark DM, Bain BJ, Bone Marrow
Pathology. DESEASES OF BONE 2011; P: 469.
14. Williams GR, The bare bones of thyroid hormones.
Endocrine Abstracts 2011; 25: 6.
15. Williams G R, Actions of thyroid hormones in bone.
Polish J Endocrinology 2009;(60)5:380-388.
16. Bonewald LF. Osteocytes In Osteoporosis,3ed.
Marcus R, Feldman D, Nelson DA, Rosen CJ, eds.
Burlington. Elsevier Academic Press 2007; 169–190.
mature and the osteocytes still irregularly
arranged. These slight differences in bone healing
between experimental and control in histological
and histochemical findings may be due to the
effect of hypothyroidism on bone healing around
titanium implants (13,15).
It was also shown that an imbalance in the levels
of T3 and T4 correlated positively with the levels
of the factors involved with bone homeostasis.
For instance, a decrease in osteoprogenitor cells,
growth factors, and cytokines, resulting in a
decreased bone apposition, was reported for
hypothyroidism (16).
The present study was done to evaluate the effect
of thyroid hormones on bone healing around
titanium implants in thyroidectomized rabbits.
The findings presented here clearly demonstrate
that clinicians should not underestimate these
conditions when dealing with patients diagnosed
with hypothyroidism that are referred for implant
placement.
REFERENCES
1. Quilligan G, Osseointegration and dental implants.
British Dent J 2010; 208: 41 - 42.
2. Kopman JA, Kim DM, Rahman SS, Arandia JA,
Karimbux NY, Fiorellini JP.Modulating the effects of
diabetes on osseointegration with aminoguanidine
anddoxycycline . J Periodontol 2005; 76: 614-620.
3. Ennis BJ. Agglomeration technology mechanism.
Chem. Eng 2010; 117 (3) 34.
4. Little JW.Thyroid disorders. Part I: Hyperthyroidism.
Oral Surg Oral Med Oral Pathol Oral Radiol Endod
2006a; 101:276-284.
5. Talaeipour AR, Shirazi M, Kheirandish Y, Delrobaie
A, Jafari F, Dehpour AR. Densitometric evaluation of
skull and jaw bones after administration of thyroid
hormones in rats. Dentomaxillofac Radiol 2005;
34:332-336.
6. Edmonds C J, Hayes S , Kermode M , Thompson
BD. Measurement of serum TSH and thyroid
hormones in the management of treatment of thyroid
carcinoma with radioiodine. British J of Radiology
1977; 50: 799-807.
7. SPSS: Statistical package of social science; version16
and17(Win/Mac/Linux,user'sguidespssinc.,Chicagoш,
USA,website,http://www.spss.com/.
8. Conti MI, Martínez MP, Olivera MI, Bozzini C,
Mandalunis
P,Bozzini
CM,
Alippi
RM.
Biomechanical performance of diaphyseal shafts and
bone tissue of femurs from hypothyroid rats Endocrine
2009; ( 36),r2: 291-298.
9. Varga F, Rumplera M, Zoehrerb R, Tureceka C,
Spitzera S, Thalera R, Paschalisa EP, Klaushofera
K.. T3 affects expression of collagen I and collagen
cross-linking in bone cell cultures. Biochem Biophys
Res Commun. 2010 ;(12):402(2-3): 180–185.
10. Freitas FR, Capelo LP, O’Shea PJ, Jorgetti V,
Moriscot AS, Scanlan TS, Williams GR, Zorn TM &
Gouveia CH . The thyroid hormone receptor betaspecific agonist GC-1 selectively affects the bone
development of hypothyroid rats. J Bone and Mineral
Research 2005; 20: 294–304.
Oral Diagnosis
79
Vol. 24(2), 2012
Prevalence of pulp stone
Prevalence of pulp stone (Orthopantomographic-based)
Zainab H. Al-Ghurabi, B.D.S., M.Sc. (1)
Areej A. Najm, B.D.S., M.Sc. (2)
ABSTRACT
Background: Pulp stones (denticles) are discrete calcified aggregates that occur most frequently in the dental pulp.
It was found in healthy, diseased and sometimes in erupted teeth. Its number appears to increase with increasing
age. It is usually detected during radiographic examination as radiopaque masses of variable size and shape. The
aims of this study were to calculate the prevalence of pulp stones in young Iraqi adults by using digital
orthopantomgraph, and to report any associations between occurrence of pulp stones with, gender, tooth type,
and dental arch.
Subject, Material and Method: A total of 390 digital panoramic radiographs were collected from oral diagnosis
department /College of Dentistry for Iraqi sample, University of Baghdad and Al-Karkh General Hospital. The sample
composed of 169 male and 221 female with mean age (26.9 years). About 10510 teeth were evaluated; pulp stones
scored as present or absent, number of stone and associations with, gender, tooth type and dental arch were
recorded
Result: From 390 (OPG) total of 3758 teeth were examined, 136 patients have pulp stone present in (276) teeth.
According to gender, 75 female with 143 teeth (51.8%) and 61 male with 133 teeth (48.1), that is mean there was no
significant difference of ( pulp stone occurrence) found between female and male. Their presence were seldom
found in the premolars 18 teeth (7%) but was much higher in the molars 258 teeth (93%) and the difference is
statistically significant. Pulp stone occurrence was significantly more common in the first molars than in the second
molars and in the first premolars than in the second premolars in each dental arch. No difference between the two
arches could be identified.
Conclusion: Pulp stones are not only incidental radiographic findings of the pulp tissue but may also be an indicator
of some serious underlying disease. On the other hand, they may provide useful information to predict about the
susceptibility of patients for other dystrophic soft tissue calcifications such as urinary calculi and calcified atheromas.
Key words: OPG radiograph, pulp stone, denticles, prevalence. (J Bagh Coll Dentistry 2012;24(2):80-84).
Studies related to the prevalence of pulp stones,
based on radiographic examinations, have been
reported with various percentages (ranging from
8% to 95%) (1, 8, 9).
With age the pulp spaces of teeth decrease in size
through the deposition of secondary and tertiary
dentine. When tooth wear, caries or operative
intervention is a feature this process becomes
more evident. In most pulps, dystrophic
calcification is found to be of a variable degree,
and even in teeth without caries or restorations
scattered calcification occurs, unrelated to disease
(10)
. Pulp stones can be structurally classified and
based on location (10,11). Structurally, there are true
and false pulp stones; the distinction being
morphological.
A third type, ‘diffuse’ or
‘amorphous’ pulp stones, is more irregular in
shape than false pulp stones, occurring in close
association with blood vessels (10, 12). True pulp
stones are made of dentine and lined by
odontoblasts, whereas false pulp stones are
formed from degenerating cells of the pulp that
mineralize (4). Such mineralization occurs in
stages; initially cell nests become enclosed by
concentrically arranged fibers (i.e. an organic
phase precedes mineralization) which then
become impregnated with mineral salts. Calcified
increments are then added (1,2). Based on location,
pulp stones can be embedded, adherent and free.
Embedded stones are formed in the pulp but with
INTRODUCTION
Pulp stones are calcified bodies in the dental pulps
of the teeth in the primary and permanent
dentition. They can be seen in the pulps of
healthy, diseased, and even unrequited teeth (1).
Their locations are more common in the coronal
than in the ridiculer portions of the pulp and they
can be observed as free, attached, and embedded
in the dentinal surface of the Pulp chamber.
Pulp stones are classified according to their
structure as true, false, and diffuse. They range in
size from small microscopic particles to large
masses that almost obliterate the pulp chamber (2).
Although the exact cause of pulp calcification is
unknown some factors have been implicated in
stone formation such as genetic predisposition (3),
orthodontictooth movement, dentine dysplasia,
dentinogenesis imperfect and in certain
syndromes such as Vandrwoude syndrome (4)
circulatory disturbance in pulp, age (5),
interactions between the epithelium and pulp
tissue, idiopathic factors (6), and long-standing
irritants like caries, deep restorations, and chronic
inflammation (7).
(1)Assistant lecturer, Department of Oral and Maxillofacial
Surgery. College of Dentistry, University of Baghdad
(2) Assistant lecturer, Department of Oral and Maxillofacial
Radiology. College of Dentistry, University of Baghdad
Oral Diagnosis
80
Vol. 24(2), 2012
ensure of the accuracy of the diagnosis, only the
teeth that were confirmed by our two examiners to
have pulp stones were scored as present.
ongoing physiological dentine formation they
become enclosed (sometimes fully) within the
canal walls (10, 13). They are found most frequently
in the apical portion of the root and the presence
of odontoblasts and calcified tissue resembling
dentine can occur on the peripheral aspect of these
stones (2). Adherent pulp stones are simply less
attached to dentine than embedded pulp stones;
the difference between adherent and embedded
can be subjective, but adherent stones are never
fully enclosed by dentine. Adherent and
embedded pulp stones can interfere with root
canal treatment if they cause significant occlusion
of canals or are located at a curve (10). They may
also become dislodged. Free pulp stones are
present within the pulp tissue proper and most
commonly seen type on radiographs (10.14).
The aim of this radiographic-based study was to
determine the prevalence of pulp stones, and to
evaluate possible associations between pulp
stones and gender, tooth type, and side, and to
compare the results with published data
presenting a new perspective in forensic medicine.
RESULTS
A total of 390 patients (221 females and 169
males) participated in the present study. The age
range of the subjects was 15 - 50 years, pulp stone
were observed in 136 patients with 276 teeth; 75
female with 143 teeth and 61male with 133 teeth,
as shown in table 1.
According to the gender the occurrence of pulp
stone in female was slightly higher than in male,
so the pulp stone in female upper 1st molar was
found in 40 teeth (14.9%),while in male 35 teeth
(12.7%). In female the upper 2nd molar was
found in 37 teeth (13.4%), while in male was 25
teeth (9%). The pulp stone in female upper 1st
premolar was found in 3 teeth (1.2%), in male was
found in 2 teeth (1.3%), in 2nd upper premolar for
female was found in 1 tooth (0.3%), while for
male was found in 2 teeth (0.7%).
For mandible the 1st molar in female was found in
78 teeth( 28.2%), while in male was found in 43
teeth (15.5%), lower 1st premolar in female was
found in 2 teeth (1.3%), in male was found in
3 teeth (1.2%), for lower 2nd premolar in female
was found in 3 teeth (1.2%), while in male was
found in 1 tooth (0.3%).Total number of teeth
with pulp stone in female was 143 teeth (51.8)
and in male was found in 133 teeth (48.1), as
shown in table 1.
According the arch also the difference between
upper and lower arch was very small so the total
number of 1st molar in maxilla was75 teeth
(27.1%), while in mandible was 78 teeth (28.2%),
and 2ns molar in maxilla was 62 teeth (22.4%),
while in mandible was 43 teeth (15.5%). The total
number of 1st premolar in maxilla was 7 teeth
(2.6%), while in mandible was 5 teeth (1.5%), and
2nd premolar in maxilla was 3 teeth (1%), while in
mandible was 4 teeth (1.4%), the total number in
the maxilla was 146 teeth (52.8), while in the
mandible was 130 teeth (47.1) so the difference
between maxilla and mandible was no significant,
as shown in table 1. P=< 0.2
According tooth type the statistic study show that,
Pulp stones were found in only 18 (6.8 %) of the
premolars and in 258 (93.2 %) of the molars
examined, with differences in occurrence being
statistically significant (p<0.01).The frequency of
pulp stones was higher in the first molars than in
the second Molars and in first premolars than in
second premolars in each dental arch.
SUBJECTS AND METHODS
A total of 390 digital panoramic radiographs
(OPG) were collected from oral diagnosis
department /College of Dentistry, University of
Baghdad and Al-Karkh General Hospital. Digital
panoramic radiographs were taken by using
DIMAX3 digital x-ray unit system machine
(Finland). The sample composed of 169 male and
221 female with mean age (26.9 years).
Information about name, age and gender had been
recorded for each patient. The digital panoramic
radiographs were examined by two oral and
maxillofacial radiologists at the same time after
put the radiograph on a viewer; Only Images of
good quality which had the clearest reproduction
of teeth without any superimposition were
included. About 10510 teeth were evaluated; teeth
with crowns or bridges that prevented adequate
vision of the pulp chamber were not included in
the study sample. Considering that teeth with deep
fillings and caries lesions are more inclined to
have pulp stones, only teeth which were noncarious and undestroyed, or those with shallow
fillings, were included. Definite radiopaque
bodies observed inside the pulp chambers of the
teeth were identified as pulp stones (Fig. 1,2) and
were scored as present or absent, number of stone
and associations with, gender, dental arch and
tooth type were recorded. No attempt was made to
determine the details of the pulp stones, such as
their size, type and location in the pulp chamber
and the condition of the associated tooth. To
Oral Diagnosis
81
Vol. 24(2), 2012
prevalence of pulp stones noted in females and
males in this study agrees with previous studies
that it is greater in female (1,7,8,16,18).
In the present study, the occurrence of pulp stones
was more frequently found in the maxilla than in
the mandible in each tooth type and location
(right- left). In the maxillary arch there are (146)
teeth with pulp stones while in mandibular arch
there are (130) teeth, so the occurrence is higher
in maxilla but the difference is not significant
statically. These results are in agreement with
previous studies (1, 17).
In the present study pulp stones were significantly
more common in first molars than in second
molars, premolars and incisors in both maxillary
and mandibular arches. Also the first premolar is
more than second premolar in both arches. This
results are in agreement with other studies (1,16-18).
A probable explanation of this result may be
related to the fact that the molars are the largest
teeth in the arch, provide a better supply of blood
to the pulp tissue and have the strongest chewing
force in the arch. This may lead to greater
precipitation for calcification (1). Also the early
eruption of the first molar will expose them for
long period of time to more degenerative changes,
thus confirming that calcification of the pulp
increases with age.
DISCUSSION
Calcification in the dental pulp can lead to
denticles, commonly known as pulp stones. They
are hard, bone-like structures that form within the
pulp of tooth, either within the crown or within
the root canals. They are usually detected on Xray examination, present as a radiopaque entity in
either the pulp chamber and/or root canal space.
They may be either singular or multiple and can
be detected easily unless they are too small or not
dense enough to show up on an x-ray. Pulp stones
are incidental findings and do not need treatment
and in the literature the incidence of pulp stones
has been investigated in many histological and
radiological studies based on periapical or
bitewing radiographs but there is no study
evaluate the prevalence of pulp stone using the
digital panoramic radiograph (OPG). When the
literature related to pulp stones was reviewed,
there were a limited number of studies regarding
the incidence of pulp stones. Moreover, the
reported rates of prevalence also differed in the
studies. Some researchers reported prevalence
based on the number of patients and teeth (1),
whereas the others represented only the rates
based on teeth numbers (8,9,15,16).
In the present study, we presented rates based
both on the number of patients and teeth. On the
basis of the number of patients we found the rate
of prevalence to be 34.8%, which is within the
reported range in the literature (1, 9, 17, 18, 19).
On the basis of numbers of teeth examined, we
found 276 teeth with pulp stones and the
percentage is 7.3 %, and this is within the range
reported by other researchers in previous studies,
Baghdady et al. in 1988 found (14.8%) out of the
6,228 teeth examined in a teenage group of 515
subjects. In another study conducted by Al-Hadi
and Darwazeh in 1998, the prevalence of pulp
stones was found to be 22.4 % in 1,028 of 4,573
teeth examined. Ranjitker et al. found the
prevalence to be 10.1 % in 333 out the 3,296 teeth
examined (17). Another report related to the
prevalence of pulp stones showed pulp stone
incidence to be 4.8 % in 747 out of the 15,326
teeth examined (9). In the present study, we found
that the prevalence of pulp stones was 15 % in
1,038 of 6,926 teeth examined. Sisman et al.
reported 15 % as pulp stone prevalence in molars
and premolars teeth of Turkish population.
According to gender, from 136 patients with pulp
stones, 75 were females (with 143 teeth have pulp
stones) and 61 were males (with 133 teeth have
pulp stones), so the female was more than males
but there are no significant differences between
the genders in each tooth type and arch. The
Oral Diagnosis
REFERENCES
1. Sisman Y, Aktan A M, Tarım-Ertas E, Çiftçi M E,
Şekerci AE . The prevalence of pulp stones in a
Turkish population. A radiographic survey. Med Oral
Patol Oral Cir Bucal 2011.
2. Johnson PL, Bevelander G. Histogenesis and
histochemistry of pulpal calcification. J Dent Res
1956; 35:714-22.
3. VanDenBerghe JM, Panther B, Gound TG. Pulp
stones throughout the dentition of monozygotic twins:
a case report. Oral Surg Oral Med Oral Pathol Oral
Radiol Endod 1999; 87:749-51.
4. kumar K. Bahetwar A., Pandey K. An unusual case
report of generalized pulp stones in young permanent
dentition. Contemp Clin Dent 2010; 1(4): 281–283.
5. Hillmann G, Geurtsen W. Light-microscopical
investigation of the distribution of extracellular matrix
molecules and calcifications in human dental pulps of
various ages. Cell Tissue Res 1997; 289:145- 54.
6. Siskos GJ, Georgopoulou M. Unusual case of general
pulp calcification (pulp stones) in a young Greek girl.
Endod Dent Traumatol 1990; 6: 282-4.
7. Sundell JR, Stanley HR, White CL. The relationship
of coronal pulp stone formation to experimental
operative procedures. Oral Surg Oral Med Oral Pathol
1968;25: 579-89.
8. Baghdady VS, Ghose LJ, Nahoom HY. Prevalence of
pulp stones in a teenage Iraqi group. J Endod 1988;
14:309-11.
82
Vol. 24(2), 2012
9. Sener S, Cobankara FK, Akgunlu F. Calcifications of
the pulp chamber: prevalence and implicated factors.
Clin Oral Investig 2009; 13:209-15.
10. Goga R, Chandler N, Oginni A. Pulp stones: a review.
International Endodontic J 2008; 41: 457–68.
11. Seltzer S, Bender IB. The Dental Pulp, 3rd ed.
Philadelphia, PA: J.B. Lippincott Company 1984.
12. Mjo¨r IA, Pindborg JJ. Histology of the human tooth.
Copenhagen: Munksgaard, 1973. pp. 61–2.
13. Philippas GG. Influence of occlusal wear and age on
formation of dentin and size of pulp chamber. J Dent
Res 1961; 40: 1186–98.
14. Sayegh FS, Reed AJ. Calcification in the dental pulp.
Oral Surgery, Oral Medicine, Oral Pathology 1968;
25: 873–82.
15. Tamse A, Kaffe I, Littner MM, Shani R. Statistical
evaluation of radiologic survey of pulp stones. J
Endod 1982; 8:455-8.
16. Al-Nazhan S., Al-Shammrani S. Prevalence of Pulp
Stones in Saudi Adults. ADJ 1991: 129-142.
17. Ranjitkar S, Taylor JA, Townsend GC. A radiographic
assessment of the prevalence of pulp stones in
Australians. Aust Dent J 2002; 47:36-40.
18. Gulsahi A., Cebeci A., Özden S. A radiographic
assessment of the prevalence of pulp stones in a group
of Turkish dental patients. International Endodontic J
2009; 42(8): 735–9.
19. Al-Hadi Hamasha A, Darwazeh A. Prevalence of pulp
stones in Jordanian adults. Oral Surg Oral Med Oral
Pathol Oral Radiol Endod 1998; 86:730-2.
Table 1: Distribution of pulp stone according to arch for both genders
`1st molar
2nd molar
Maxilla `1st premolar
2nd premolar
total
`1st molar
2nd molar
Mandible `1st premolar
2nd premolar
total
Total
No.
35
25
4
2
66
38
25
3
1
67
133
Male
%
12.68%
9.%
1.4%
0.7%
23.9%
13.76%
9%
1.2%
0.35%
24.2%
48.1%
Female
No.
%
40 14.49%
37
13.4%
3
1.2%
1
0.3%
81
29.1%
40 14.49%
18
12.5%
3
1.2%
1
0.35%
62
22.8%
142
51.8
Total%
75 (27.1%)
62 (22.4%)
7 (2.6%)
3 (1%)
146 (53.%)
78 (28.2%)
43 (15.5%)
6 (2.4%)
2 (0.7%)
130 (47.1)
100%
P< 0.2
Figure 1: Digital Panoramic Radiograph showing pulp stone.
Figure 2: A: pulp stones in the pulp chamber of maxillary and mandibular second molars.
B: pulp stones in the pulp chamber of maxillary first and second molars. 35% (276 teeth of 136
subjects) with pulp stone
Oral Diagnosis
83
Vol. 24(2), 2012
Figure 3: This figure show the percentage of teeth involved with pulp stone.
5% 1s t premolar
55% 1st molar (Red)
38% 2nd molar (Green)
5% 1st premolar (Blue)
2% 2nd premolar (violet)
No significant difference between maxilla and mandible
Figure 4: Pulp stone distribution according to tooth type for both arcs
Oral Diagnosis
84
Vol. 24(2), 2012
Evaluation of the haemostatic
Evaluation of the haemostatic action of povidone- iodine in
dental extraction (Clinical and follow up prospective
study)
Ali Q.L. Al-Amiri, B.D.S, M.Sc. (1)
ABSTRACT
Background: This study aimed to evaluate the haemostatic action of povidone-iodine by irrigation of the alveolar
sockets after extraction against the use of normal saline alone.
Materials and Methods: This clinical prospective study included 60 patients (35 males, 25 females), ranging in age
from 20 to 60 years. All minor oral surgery patients at (Oral& Maxillofacial Surgery Department in College of Dentistry/
Babylon University) from March 2011 to January 2012. The patients were divided equally into treatment& control
groups. Povidone-iodine (1%, w/v) was used for irrigation of extraction sockets in the treatment group and saline was
used in the control group.
Results: The 60 patients were divided equally into treatment& control groups. Povidone-iodine (1%, w/v) was used for
irrigation of extraction sockets in the treatment group and saline was used in the control group. In the treatment
group, 24 patients showed cessation of bleeding compared to only 7 in the control group. Povidone-iodine
significantly (P < 0.01) controlled bleeding as compared to saline.
Conclusion: Iodine is corrosive due to its oxidizing potential while povidone is a thickening and granulating agent;
together they have a chemocauterizing effect that could be the reason for the cessation of bleeding.
Keywords: Povidone iodine, Haemostatic action. (J Bagh Coll Dentistry 2012;24(2):85-87).
INTRODUCTION
The use of topical antimicrobial agents is
common in clean and contaminated surgical
wounds, based on the premise that reduction of
superficial bacterial contamination aids wound
healing. Povidone iodine is a widely used and
highly potent antiseptic. Iodine was first used
medically to produce inflammation and
obliteration of serous cavities. It is commonly
used both on intact skin in preparation for surgery
and on open wounds. Acute lacerations are soaked
in iodine and surgical wounds are freely irrigated
with it10. Povidone-iodine is formed by binding
free iodine to polyvinyl-pyrrollidone (PVP), a
solubilizing agent. This is done to decrease the
toxicity of the iodine. As iodine is liberated from
the PVP molecule it exerts its antimicrobial
effect3.
Once released, iodine is toxic to microorganisms
because it combines irreversibly with tyrosine
residues of proteins, interferes with the formation
of hydrogen bonding by some amino acids and
nucleic acids, oxidizes sulfydryl groups and reacts
with sites of unsaturation in lipids4&7.
Povidone iodine is a broad spectrum antimicrobial
solution effective against a variety of pathogens
including Staphylococcus
aureus.
However,
similar wound infection rates have been reported
in adult and pediatric populations with saline
irrigation versus 1% povidone-iodine2&13.
(1)Assistant Lecturer, Department of Oral & Maxillofacial
Surgery, College of Dentistry, Babylon University.
Oral and Maxillofacial Surgery and Periodontology 85
In addition to antibiotic prophylaxis, preparation
of the surgical field with povidone iodine has
been widely recommended12.
Iodine is corrosive due to its oxidizing potential
while povidone is a thickening and granulating
agent; together they may have a chemocauterizing
effect that could be the reason for the cessation of
bleeding6.
In oral surgery, Povidone-iodine is used as an
irrigant of the alveolar sockets following dental
extractions as antiseptic& haemostic. Extraction
of diseased and malformed teeth is an essential
part of oral surgery. Indications for extraction
include: end-stage periodontal disease, end-stage
endodontic disease, pulp exposure when
endodontic
treatment
is
not
elected,
malocclusions, crowding, retained deciduous
teeth, trauma, and so forth. The present authors
observed by chance that there was a cessation of
fresh bleeding in some patients after irrigation
with Povidone-iodine5.
For medical uses, saline is often used
to flush wounds and skin abrasions. Normal saline
will not burn or sting when applied8.
Normal saline is isotonic and the most commonly
used wound irrigation solution due to safety
(lowest toxicity) and physiologic factors. A
disadvantage is that it does not cleanse dirty,
necrotic wounds as effectively as other solutions
2&13
.
This study aimed to evaluate the haemostatic
action of povidone-iodine by irrigation of the
alveolar sockets after extraction against the use of
normal saline alone.
Vol. 24(2), 2012
This clinical study was carried out on (60)
healthy Iraqi patients who needed dental
extractions. These patients were (35 males, 25
females), ranging in age from 20 to 60 years
(Table 1-1). All minor oral surgery patients with
multiple extractions (multiple sockets) at (Oral&
Maxillofacial Surgery Department in College of
Dentistry/ Babylon University) from March 2011
to January 2012. The patients were divided
equally into treatment& control groups. The
alveolar sockets of the treatment-group patients
were irrigated immediately after extraction 3
times by using disposable syringe of (5cc) with
povidone iodine 1% (w/v) (Betadine, WinMedicare, Germany) plus saline (sodium chloride
0.9%, w/v; Parenteral Drugs, Germany) following
dental extractions, whereas those of the controlgroup patients were irrigated with saline only.
Spontaneous stoppage of bleeding from the socket
following irrigation was considered as significant
haemostasis. Haemostasis was examined visually.
Care was taken not to compress the socket to
reduce
the
linear
micro-fractures
until
observations were made.
All the patients were followed up after 24 hours,
and blood clot inside the sockets was firm without
complications.
Inclusion and exclusion criteria for the patients
are listed as follow:
Inclusion Criteria: (Age between 20 and 60 years,
No history of bleeding disorders, No history of
complications of previous extractions).
Exclusion criteria: (Patients on anti-coagulant
therapy, History of hypersentivity to iodine,
Long-term NSAID therapy, menstrual cycle&
hormonal changes in females, Conditions, such as
periodontitis, gingivitis and dental abscess).
RESULTS
The (60) patients were divided into 2 groups
(n = 30), the treatment and control groups; the
control group had 12 women and 18 men, and the
treatment group consisted of 16 women and 14
men (Table 2).
In the treatment group, 24 of the 30 patients
showed spontaneous cessation of fresh bleeding
(Table 3) following irrigation of the extraction
socket with povidone iodine (1% w/v), while this
was observed in only 7 of the 30 patients irrigated
with saline (Table 4). This observation was made
before drying the socket with gauze following
which the sockets were compressed. Postextraction bleeding was significantly controlled
by povidone iodine as compared to saline. No
postoperative complications were observed in the
patients of either group.
DISCUSSION
The most common age group involved was 2130 years; they showed a good response of
haemostasis with povidone iodine due to their
good health status with simple extractions. This
age group comes into agreement with the age
group of 15-33 years in the study by1
We found in this study, the haemostasis response
in males was higher than females, and this might
be due to the exclusion criteria in the point which
is related to females, and this comes into
agreement with the study by9 .
Povidone is a synthetic polymer of 1vinylpyrrollidone, which is hygroscopic and
readily soluble in water. It is also a thickening and
dispersing agent with tablet binding capacity
(wide firm binding) (SEAN, 2002). Iodine has a
corrosive effect on tissues due to its oxidizing
potential11.
It seems possible that the haemostatic action of
povidone iodine is due to the corrosive property
of iodine and the thickening and binding
properties of povidone. Iodine may chemocauterize the tissues while povidone may aid in
clotting6.
We found in this study that 24 patients in the
treatment group have a haemostasis with
irrigation by povidone iodine due to the good
health status and simple cases of extractions,
while the other 6 patients have no response to
haemostasis, and the cause might be due to the
lower health status when compared with the
previous 24 patients. This result comes into
agreement with the result in the study by8.
While the haemostatic effect of normal saline is
less than that of povidone iodine, because normal
saline do not have a chemo-cauterizing action on
the tissues, but just flush the wounds and make
isotonic action with the wounds. This comes into
agreement with2&13 .
REFERENCES
1. Alexander RE, Dental extraction wound management:
a case against medicating postextraction sockets, J
Oral Maxillofac Surg 2000; 58: 538–51.
2. Chisholm CD, Cordell WH, Rogers K, Woods JR.
Comparison of a new pressurized saline canister
versus syringe irrigation for laceration cleansing in the
emergency department. Ann Emerg Med 1992;
21(11):1364-7.
3. Dedo DD, Alonso WA, Ogura JH, Povidone-iodine
an adjunct in the treatment of wound infections,
dehiscences and fistulas in head and neck surgery,
Trans Am Acad Opthalmol Otolaryngol 2005; 84: 68–
74.
Vol. 24(2), 2012
4. Gottardi W. Iodine and iodine compounds. In: Block
SS (ed). Disinfection, sterilization and preservation.
Philadelphia: Lea & Febiger; 2003. p.183–96.
5. Hellem S, Nordenram A. Prevention of postoperative
symptoms by general antibiotic treatment and local
bandage in removal of mandibular third molars, Int J
Oral Surg 1973; 2: 273.
6. Kumar BPR, Maddi A, Ramesh KV, Baliga MJ, Rao
SN, Meenakshi. Department of Oral and Maxillofacial
Surgery, College of Dental Surgery, Mangalore,
Karnataka, IndiaDepartment of Pharmacology,
Kasturba Medical College, Mangalore, Karnataka,
India Department of General Surgery, Kasturba
Medical College, Mangalore, Karnataka, India, 2006.
7. Markham SM, Rock J. Preoperative care. In: Rock JA,
Thompson JD (ed): Te Linde's Operative Gynaecology
8th ed. Philadelphia: Lippincott-Raven; 1997. p. 233–
43.
8. Principi T, Komar L. A critical review of a
randomized trial of nebulized 3% hypertonic saline
9.
10.
11.
12.
13.
with epinephrine in the treatment of acute bronchiolitis
in the emergency department. J Popul Ther Clin
Pharmacol 2011; 18(2): e273–4. PMID 21633141
Sweetman SC (ed). Disinfectants and preservatives.
In: Martindale the complete drug reference. 33rd ed.
London 2002. p. 1155.
Senn N. Iodine in surgery with special reference to its
use as an antiseptic. Surg Gynecol Obstet 1905; 1: 1–
10.
Swaryard EA, Lowenthal N (eds). Pharmaceutical
Necessities. In: Remington's Pharmaceutical Sciences.
18th ed. Philadelphia 1990. p. 1307.
Sweet RL, Gibbs RS, Editors, Wound and episotomy
infection. In: Infectious Diseases of the female Genital
Tract 2nd ed. Baltimore: Williams and Wilkins; 2000.
p. 374–82.
Watt BE, Proudfoot AT, Vale JA. Hydrogen peroxide
poisoning. Toxicol Rev 2004; 23(1): 51-7.
Table 1: Demography or age range of the patients
Age range
20
21-30
31-40
41-50
51-60
Total
Frequency
3
22
17
15
3
60
Percentage
5%
31.7%
33.3
25%
5%
100%
Treatment group
2
17
5
4
2
30
Control group
1
5
12
11
1
30
Table 2: Gender or sex distribution of the patients (Control group& Treatment group)
Gender
Male
Female
Total
Number of cases
(control group)
18
12
30
Percentage
60%
40%
100%
Number of cases
(treatment group)
14
16
30
Percentage
46.67%
53.33%
100%
Table 3: The haemostatic action of povidone iodine on the treatment group (significant)
Cessation of bleeding
Yes
No
Total
Number of cases
24
6
30
Percentage
80%
20%
100%
Gender
13males+11females
1males+5females
30
Table 4: The haemostatic action of normal saline on the control group (non significant)
Cessation of bleeding
Yes
No
Total
Number of cases
7
23
30
Percentage
23.33%
76.67%
100%
Gender
5males+2females
13males+10females
30
Vol. 24(2), 2012
A comparison between
A comparison between the antibacterial and antifungal
effects of chlorhexidine digluconate (An in vitro study)
Firas H. Qanbar, B.D.S., M.Sc. (1)
ABSTRACT
Background: The use of antimicrobial agent to control plaque and oral disease has been advocated for a number
of years. Different compounds have been delivered through mouth rinses or tooth pastes or by topical application.
The purpose of this research is to find out and to compare between the antibacterial and antifungal properties of
Chlorhexidine digluconate 0.2%.
Materials and methods: Mutans streptococci & Candida albicans were isolated from 25 saliva samples from healthy
volunteers (age range between 21-23 yrs). These isolates were purified and diagnosed according to morphological
characteristics and biochemical tests. Chlorhexidine 2mg/ml (0.2%) was used in the in vitro; susceptibility of Mutans
streptococci and Candida albicans were tested by agar diffusion technique.
Results: Agar diffusion technique showed that Chlorhexidine (0.2%) inhibited the growth of Mutans Streptococci, and
Candida albicans, but the effect of Chlorhexidine (0.2%) on Candida albicans was more patent than on Mutans
Streptococci in vitro. There was statistically highly significant difference (p<0.001) between the antifungal and
antibacterial effects of Chlorhexidine on the sensitivity of the isolates,
Conclusion: Chlorhexidine digluconate 0.2% was more potent as an antifungal than an antibacterial agent.
Key words: Chlorhexidine digluconate, mutans streptococci, Candida albicans. (J Bagh Coll Dentistry 2012;24(2):8890).
INTRODUCTION
The use of antimicrobial agent to control plaque
and oral disease has been advocated for a number
of years (1). Different compounds have been
delivered through mouth rinses or tooth pastes or
by topical application. Some chemical agents have
proven to be helpful against plaque accumulation
and thereby to some extent also against caries (2).
Oral mutans streptococci (MS) are responsible for
50–70% of all cases of bacterial endocarditis. The
origins of endocarditis lie in invasion of the
vascular system through lesions in the oral
mucosa (3). These streptococci can attach to the
proteins covering the tooth enamel, where they
then convert sucrose into extra cellular
polysaccharides (mutan, dextran, levan) (4). These
sticky substances, in which the original bacterial
layers along with secondary bacterial colonizers
are embedded, form dental plaque. The final
metabolites of the numerous plaque bacteria are
organic acids that breach the enamel, allowing the
different caries bacteria to begin destroying the
dentin (5).
A few fungi have developed a commensal
relationship with humans and are part of the
indigenous microbial flora (e.g., various species
of Candida, especially Candida albicans) (6). The
first exposure to fungi that most humans
experience occurs during birth, when they
encounter the yeast Candida albicans (C.
albicans) while passing through the vaginal canal.
C. albicans accidentally penetrate barriers such as
intact mucous membrane linings, or when
immunologic defects or other debilitating
conditions exist in the host, these conditions
favorable for fungal infections (7).
Stimulated saliva samples were collected under
standard conditions to obtain 25 microbial
samples. Volunteers with no medical history aged
21-23 years were selected to participate in this
study. Each individual was instructed to chew a
piece of Arabic chewing gum (0.4-0.5g) for five
minutes to stimulate salivary flow as much as
possible then saliva was collected in sterilized
screw capped bottles. The collected saliva was
homogenized by vortex mixer for two minutes.
Ten-fold serial dilutions were prepared using
sterile normal saline. Two dilutions were selected
for each microbial type and inoculated on the
following culture media which are prepared
according to the manufacturer’s instructions:
1. Mitis-Salivarius Bacitracin Agar (MSB Agar),
the selective media for MS: 0.1ml was withdrawn
from dilutions 10-1 and 10-2 using adjustable
micropipette with disposable tips and then spread
in duplicate by using sterile microbiological glass
spreader on the plates of MSB agar, the plates
were then incubated anaerobically by using a gas
pack supplied in an anaerobic jar for 48 hrs at
37°C followed by aerobic incubation for 24hrs at
37°C.
2. Sabouraud Dextrose Agar (SD Agar), the
medium is selective for the cultivation and
isolation of C. albicans: 0.1ml was withdrawn
from dilutions 10-1 and 10-2 using adjustable
micropipette with disposable tips and then spread
Vol. 24(2), 2012
in duplicate by using sterile microbiological glass
spreader on the plates of SD agar then the plates
were incubated aerobically for 48 hrs at 37° C.
A single colony from MS and C. albicans
separately were transferred to 10 ml sterile BHI-B
and then incubated for 24 hrs aerobically at 37°C
to activate the inoculums.
The purity of the isolates was checked by
reinoculation of 0.1 ml of the isolates from BHI-B
suspensions on their selective media by spreader
as mentioned before, then selective colony from
each isolate was transferred to 10 ml of sterile
BHI-B and incubated for 24 hrs aerobically at
37°C. One ml from this broth was transferred to
10 ml sterile BHI-B and then 1 ml sterile glycerol
was added to the inoculated broth; the tubes were
labeled (the type of inoculum and the date of
inoculation) and freezed until use. This procedure
was repeated twice monthly. A colony was picked
up from MSB agar and SD agar plates separately
under sterilized conditions and subjected to
gram’s stain; all the isolates were gram positive.
The motility of all types of microbial cells was
examined under microscope by direct smear and
without staining; the isolates were non- motile.
Catalase production test was performed; a small
amount of pure isolates of MS cultures was
transferred using a sterile loop to the surface of
clean dry glass slide. Drops of hydrogen peroxide
3% immediately placed onto a portion of bacterial
culture on the slide, absence of gas bubbles
indicates the absence of catalase enzyme.
acid production from the fermentation reaction
(Fig. 2).
Figure 2: Biochemical identification of
Mutans streptococci.
A: Positive control tube (agar and bacteria
without mannitol).
B: Study tube (agar and mannitol inoculated
with MS).
C: Negative control tube (agar and mannitol
without bacteria).
C. albicans diagnosed according to morphological
properties using Gram’s stain (Fig. 3) and germ
tube formation in human plasma.
Figure 3: Gram's stain of C albicans showing
gram positive stains (1000x magnification).
Figure 1: MS colonies on MSB agar (20 x
magnifications).
Cystine Trypticase-mannitol media had been used
to test the ability of MS to ferment the mannitol
which was added in a concentration of 1% to the
Cystine Trypticase Agar media (which was
prepared according to the manufacturer
instructions biomerieux Company),
then
distributed into screw capped bottles (10ml in
each bottle) and autoclaved, each bottle was
inoculated with 0.1ml of pure MS isolates and
incubated aerobically at 37°C for 48 hrs.
Changing in color from red to yellow indicated a
positive reaction in comparison to the positive
control (agar and bacteria without mannitol) and
negative control (agar and mannitol without
bacteria) because of pH reduction as a result of
All culture media and normal saline were
sterilized by autoclave at 121°C and pressure of
15 pound/inch2 for 15 minutes except for the CTA
medium which was sterilized by autoclaving for
10 minutes. Bacitracin solution was filtered using
millipore filter size 0.20 µm. Sterilization of all
cleaned glass wares was conducted by hot air
oven at 180°C for 1 hr. Benches and floor of the
laboratory were disinfected by bleaching
antiseptic solution (Fas).
Agar diffusion technique was applied to study the
antimicrobial effects of CHX against the isolates
spread on Brain Heart Infusion Agar (BHI-A);
wells of equal sizes and depths were prepared in
the agar using Kork porer for the evaluation of
CHX. Each well was filled with 50µl of 0.2%
CHX. Plates left for 15 minutes in the room
temperature and then incubated aerobically for 24
hrs at 37°C. Inhibition zones’ diameters were
measured using a scientific ruler.
Vol. 24(2), 2012
RESULTS
Diameters of inhibition zones for CHX were
found to be greater in the plates inoculated with
C. albicans than those formed in the plates of MS
(Fig. 4). Student’s t-test showed highly
significant differences among different CHX
inhibitions’ zones (Table 1).
Results of agar diffusion experiments are affected
by many factors like the molecular weights and
concentrations of the antimicrobial agent, the
types of the isolates and the fluidity and/or
stickiness of the solutions. The thickness of the
agar was well controlled through out the
experiment by measuring the volume of the agar
while it was liquid before poring it into the same
sized petridishes in order to avoid the variation of
the results which will appear as a result of agar
thickness variations. The size of inoculums was
controlled by using adjustable micropipettes with
disposable tips to ensure that equal volumes of the
isolates’ suspensions were dispensed into all the
plates and the same precaution was carried out for
the volumes of the extracts and CHX which were
dispensed into the wells made in the agar plates.
biological membranes like ergosterol (8). The
sensitivity of MS and C. albicans to the aqueous
extract of eucalyptus could be due to the
hereditary contents or attraction ability or the
permeability of the cell wall of the
microorganisms. CHX disrupts cell membrane
and cell wall permeability of many Gram- positive
and Gram-negative bacteria and interferes with
the adherence of plaque-forming bacteria, thus
reducing the rate of plaque accumulation (9), it can
inhibit the adenosine triphosphatase (ATPase)
which is an important enzyme that is linked to
cytoplasmic membrane and thus can inhibit the
process of returning potassium ions into cells in
exchange for sodium and hydrogen ions, also
inhibits metabolic enzymes (10).
Differences in the microbial susceptibility to CHX
could also be due to the hereditary contents of the
isolates which may alter the susceptibility of the
organisms by modifying the targets to be attacked
by the active constituents like the proteins and
lipids of the microbial membrane or inhibiting the
constituents of the leaves' extract or modifying the
structures of these constituents by some enzymes
rendering them to less effective compounds.
REFERENCES
Figure 4: Comparison between the mean
diameters of inhibition zones of CHX in
relation to Mutans streptococci and C.
albicans.
Table1: Statistical analysis for the sensitivity
of Mutans streptococci, lactobacilli and C
albicans to different concentrations of
aqueous extract of eucalyptus using
Student’s t- test.
Isolates
MS & C. albicans
CHX
0.2%
t-value
t-value
16.43 0.000 ****
***P<0.001 High significant
Results showed that there were some differences
in the sensitivity of the isolates to CHX; it can be
explained by the differences between eukaryotic
cells (fungi) and prokaryotic cells (bacteria)
especially of the cell wall. The cell walls
of fungi consist of nearly 90% carbohydrate
(chitin, glucans, mannans) and fungal membranes
are rich in sterol types not found in other
1. Milner JL, Stohl EA, Handelsman J. A resistance gene
from Bacillus cereus. J Bacteriol 1996; 178: 4266–72.
2. Thylstrup A, Fejerskov O. Textbook of clinical
cariology. 2nd ed. Copenhagen: Munksgaard; 1994.
3. Krasse B. Caries risk: A practical guide for assessment
and control. Chicago: Quintessence Publishing Co;
1985.
4. Genco, VanDyke, 1986. Quoted by Holt JG, Krieg
NR,
Sneath
PHA, Staley JT, Williams
ST.
Bergey's manual of determinative bacteriology. 9th
ed. Baltimore & Maryland: Williams & Wilkins; 1994.
5. Kayser FH, Bienz KA, Eckert J, Zinkernagel RM.
Medical microbiology. New York: Thieme; 2005. p.
243.
6. Murphy JW, Friedman H, Bendinelli M. Fungal
infections and immune responses. New York: Plenum
Press; 1993.
7. Kwon-Chung KJ, Bennett JE. Medical mycology.
Philadelphia: Lea & Febiger; 1992.
8. Kayser FH, Bienz KA, Eckert J, Zinkernagel RM.
Medical microbiology. New York: Thieme; 2005, p
243.
9. Samaranayake L. Essential microbiology for dentistry.
3rd ed. Philadelphia: 2006.
10. Autio J. The role of chlorhexidine in caries prevention.
Oper Dent 2008; 33(6): 710-6.
Vol. 24(2), 2012
Effect of in-dental clinic
Effect of in-dental clinic bleaching agents on the releases of
mineral ions from the enamel surfaces in relation to their
times intervals
Afnan AL-Shimmer, B.D.S. (1)
Mohammad Al-Casey, B.D.S., M.P.H., M.S.P.H .(2)
ABSTRACT
Background: alterations of the enamel after topical application of bleaching agents, presenting as major
consequences are: ions release, increased superficial roughness, stronger bacterial attachment and hardness
alteration. The aims of the study were to evaluate the effects of two different types of bleaching agents for vital teeth
by using with light source on the release of ions (Calcium and phosphate ions) from the enamel surface.
Materials and methods: Fifty three sound enamel surface for calcium ions release and Fifty three sound enamel surfaces for
phosphate ions, were subject to treated with bleaching agents (35% hydrogen peroxide and carbamide peroxide) and
then application of light and laser radiation to activate the bleaching agents. Spectrophotometer and Buck scientific
atomic absorption spectrophotometer were used to measure the ions release from enamel surface.
Results: highly significant increase in the release of ions (calcium ions), while significant increase in the release of ions
(phosphate ions) in relation to the times intervals.
Conclusions: In this study showed that release of calcium ions from enamel surface after treated with both 35%
carbamide peroxide and 35% hydrogen peroxide increase with increase the time and compared with release of
phosphate ions release and control groups.
Key word: Enamel surface, Ions release, Bleaching agents. (J Bagh Coll Dentistry 2012;24(2):91-93).
INTRODUCTION
In recent years, with more and more people
interested in cosmetic enhancement, the demand
of tooth bleaching is increasing sharply. Not only
conventional bleaching of non-vital teeth, the
needs for bleaching of vital teeth is also increase
(1)
Tooth bleaching can be performed externally,
termed vital tooth bleaching (2) various methods
and bleaching chemicals have been used
extracoronally on teeth with vital pulps (3).
Bleaching systems that act by means of strong
oxidizers are mostly used for brightening of teeth.
Depending on the form of application, the
concentrations lie between 10-35% peroxide. In
particular, 35% concentrated hydrogen peroxide
or carbamide peroxide are used. The action
mechanism is based on oxidative discoloration of
incorporated colorants. However, strong oxidizers
also degrade structure-relevant in the enamel (4).
The most popular technique for the in-office
bleaching of vital teeth involves 35% hydrogen
peroxide, with phosphoric acid to facilitate
bleaching and etching the teeth either a heating
element or a light source to enhance the action of
the peroxide (5). The use of optical radiation in the
so called light assisted tooth bleaching procedure
has been suggested to enhance effect of the
bleaching agent (6).
(1) MSc student, Department of preventive dentistry, College of
(2) Professor, Department of preventive dentistry, College of
Orthodontics, Pedodontics, and Preventive Dentistry91
Many authors have demonstrated alterations of
the enamel after topical application of bleaching
agents, presenting as major consequences are:
ions release, increased superficial roughness,
stronger bacterial attachment, hardness alteration,
color alteration, and adhesion to resinous
materials (7) . Research in this area has showed
penetration easily the hydrogen peroxide, because
of its low molecular weight, passes through the
enamel and dentin to the pulp(8).
One hundred six non carious maxillary first
premolar teeth extracted for orthodontic purpose.
Teeth were fixed in temporary state in an auto
polymerizing resin base (cold cure resin) and
became ready for application. The bleaching
process was done according to manufacturers
instruction and this done by using a disposable
brush to paint the totally cover the surface of the
tooth and the time of application is 8 min and each
sample three times application of pola office gel,
each samples exposure to 40 second a curing light
machine and Laser unit used for this study is
continuous power (CW) Nd-YAG laser for
exposure to the bleaching agent This step was
repeated for four times for each sample as
recommended by the manufacturers instructions
Then the samples were washed using a continuous
jet of syringe for one minute to dissolve the
bleaching agent on the tooth surface and dried with
air syringe for 30 seconds. Then storages in 10ml of
Vol. 24(2), 2012
demineralization ( loss of mineral ) result in
decreased the enamel microhardness.
This may be due to higher concentration of
peroxide and formed free radical is higher from
laser than from halogen light, so causes more
demineralization to the enamel ( Loss of calcium
ions) this result agree with some study (10,11),
concluded that 35% HP with light may cause
significantly more loss of Ca+2 from the enamel
surfaces than lower concentration CP.
The treatment with carbamide peroxide and
activated with laser and halogen light show in the
revealed highly significant different ( P< 0.001 )
for both light source this may be indicated
changes in the enamel crystal composition and
alter enamel structure the result agree with other
research ( 12-14) , show that bleaching with
hydrogen peroxide or hydrogen peroxide
releasing agents may result in significant decrease
of enamel calcium and phosphate content and
morphological alteration in the most superficial
enamel crystallites. In this study show that
carbamide peroxide causes local microstructure
and chemical changes, such as loss phosphate
ions, as show in the ANOVA table, represent
highly significant different between the group at
three period of time for the two activation used (
Halogen light and laser radiation ), this indication
alteration in the composition of enamel these
result agree with other result showed that in-office
bleaching caused deleterious alterations in the
composition and structure of enamel that
significantly affected the crystalline and
mineralization of the tissue(15) . In this study
showed that the means of release the calcium ions
from sound enamel surface is higher than the
phosphate ions as showed in the table (1) this is
may be due to the concentration of the calcium
ions is higher than the phosphate ions in the
enamel surface of permanent teeth, this result
agree with many study (16, 17), Calcium ions
followed by phosphorus ion were the major
elements in enamel sample.
de-ionized water in sterilized glass container and
returned to incubator in 37Ċ until the time of
testing.
Essential elements release from sample in deionized water was analyzed at the poisoning
consultation centre /specialized surgeries hospital
by using Buck scientific atomic absorption
spectrophotometer
following
standardized
procedure.
RESULTS
For statistical analysis was used in this study:
means and standard deviation values of ions
release from enamel surface that activated by two
different light source and for all groups are listed
in table (1).The data revealed that there was
increase in ions release values for the sound
enamel surface over the time for all the groups
and after bleaching with both 35% carbamide
peroxide and 35% hydrogen peroxide. Statistical
analysis of data by using ANOVA test show in
table (2) revealed that there was a non- significant
difference (P>0.05) among the control groups,
while highly significant difference (P<0.0001)
among when use light source ( halogen light ) and
also highly significant difference (P<0.0001)
among the different groups when use light source
(laser light) at different period of times for the
release of calcium ions, while for the phosphate
ions show in the table (3) revealed that there was
a non-significant difference (P>0.05) among the
control groups, while highly significant difference
(P<0.001) among the different groups when
bleaching is done using light source ( halogen
light ) and also highly significant difference
(P<0.001) among the different groups when use
light source (laser light) at different period of
times.
DISCUSSION
It is obvious from the results of this study the
enamel surface when treated with 35% hydrogen
peroxide gel and activated with the halogen light
resulted in marked increase in the means of
release of calcium ions at the 96hrs, in compared
to the control groups. While result found, when
treated with 35% hydrogen peroxide gel and
activated with the laser irradiation for the same
period of time ( 96hrs. ), found the means is
higher than that of halogen light and also much
higher in compared to control.
This adverse effect of bleaching on the enamel
mineral ( ions ) was noted by many researches,
may be due to the concentration or type of the
bleaching agent used, this agree with the many
study (9), showed that after treatment bleaching
with high concentration of hydrogen peroxide,
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Vol. 24(2), 2012
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carbamide peroxide, carbopol and/or glycerin on enamel
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Table 1: Descriptive statistics of ions release from enamel surface of all groups in ppm.
Groups
Control group
Laser
Radiation
35%CP
Light
cure
35%CP
Laser radiation
35% H.P
Light cure.
35% H.P
Times
48hours
72hours
96hours
48hours
72hours
96hours
48hours
72hours
96hours
48hours
72hours
96hours
48hours
72hours
96hours
Calcium ions
Mean
SD
0.2480 0.0295
0.2772 0.04667
0.3350 0.01029
0.4625 0.1573
3.1812 0.4805
4.9370 0.5203
0.3187 0.2605
2.3035 0.3229
3.2870 0.4148
2.4625 0.3433
3.4862 0.3118
4.3280 0.2851
0.7110 0.0792
2.6412 0.3128
3.8240 0.5551
Phosphate ions
Mean
SD
0.2480 0.0295
0.2772 0.04667
0.3350 0.01029
0.6597 0.0208
2.3664 0.2732
4.1357 0.7358
0.5885 0.0788
1.7162 0.1943
2.4145 0.6644
0.7912 0.0404
1.4092 0.0949
2.7112 0.2350
0.2652 0.0609
1.3780 0.1220
1.8406 0.1030
Table 2: ANOVA test for release of ions (calcium ions ) from enamel surface at different period
of time when activated with laser light and halogen light .
Agents
control
35%H.P
Act. With laser
35%H.P
Act. With light
df
2
F-test
7.450
P-values
.012
Sig
NS
2
35.323
.000
HS**
2
71.868
.000
HS*
Table 3: ANOVA test for release of ions ( phosphate ions ) from enamel surface at different
period of time when activated with laser light and halogen light .
Agents
control
35%H.P
Act. With laser
35%H.P
Act. With light
df
2
F-test
7.450
P-values
.012
Sig
NS
2
174.887
.000
HS**
2
269.106
.000
HS*
HS = Highly significant different (p< 0.0001).
NS = Non signifiant different (p>0.005).
Vol. 24(2), 2012
Physicochemical characteristic
Physicochemical characteristic of unstimulated and
stimulated saliva with different chewing gum stimulation
Alhan A. Qasim, B.D.S., M.Sc. (1)
Eman K. Chaloob, B.D.S., M.Sc. (1)
ABSTRACT
Background: Gum chewing is a common habit in many countries. Both sucrose containing and sugar-free gum
stimulate salivary flow, increase in saliva flow lead to more frequent replenishment and greater supply of
antibacterial factors, saline, buffers, minerals and other beneficial constituents, increase pH and buffer capacity of
whole saliva. The aim of the present study was to investigate the effect of different chewing gums on the salivary
constituents including some elements (Magnesium, Calcium, Copper and Zinc)(chemical),PH and flow
rate(physical)characteristic.
Materials and Methods: Saliva samples was collected from dental students/college of dentistry 23 age stimulated by
three types of chewing gum (mastic, Arabic, sugar) and control group (unstimulated saliva), pH and saliva flow rate
was recorded for four groups. Biochemical analysis was assessed for some salivary elements, (Magnesium, Calcium,
Copper, and Zinc) and its relation with different chewing gum and control group. Student's t-test, ANOVA and LSD
test was used for statistical analysis. Also mean and standard deviation was recorded.
Results: Mean value of pH was found to be high in three types of chewing gum with highly significant difference
comparing with control group. A significant difference in flow rate was found between control and sugared gum
group. Mg and Ca ione was found to be highly significant between mastic gum group and other three groups , as
well as highly significant difference was recorded among four groups of saliva in Cu ione, while no significant
difference was showed between Zn ione and four groups.
Conclusion: Chewing gum include natural (mastic and Arabic) and sugared was increases salivary pH. Use of
chewing gum especially mastic and Arabic can enhance the remineralizing potential of the mouth, probably by
stimulating salivary flow which may lead to rise salivary elements.
Key words: Chewing gum, salivary elements, Mastic gum, Arabic gum. (J Bagh Coll Dentistry 2012;24(2):94-98).
INTRODUCTION
Chewing gum probably has its origin in ancient
Egypt and in Mayan Indian times as these peoples
are known to have chewed the resin of trees(1)also,
in 50A.D.,when the Greeks sweetened their breath
and cleansed their teeth with arsine called
mastiche, which was obtained from the bark of the
mastic tree so that the chewing gum first became
an aid to maintaining oral health(2),in addition to
that chewing gum increases salivary flow rate
and enhance the protective properties of saliva
this because the concentration of bicarbonate and
phosphate is higher in stimulated saliva, and the,
resultant increase in plaque pH and salivary
buffering capacity prevent demineralization of
tooth
structure.
Morevere,
the
higher
concentration of calcium, phosphate, and
hydroxyl ions in such saliva also enhances
(3,4)
remineralization
.Many
studies
have
demonstrated the ability of mastic gum to
suppress the growth of cariogenic bacteria and to
reduce the salivary streptococcus mutans
count(5),as well as another study concept that the
use of mastic gum and xylitol containing chewing
gum for 20 minutes after an acidogenic challenge
can enhance the remineralizing potential of the
mouth, probably by stimulating salivary flow (6),
also a study by Bakhtiari (7)compared the rate of
(1) Lecturer. Pediatric and Preventive Department. College of
dentistry, University of Baghdad.
the secreted saliva and its pH after chewing
xylitol-containing gum and mastic gum in case
and control groups.The results indicated that both
mastic gum and xylitol chewing gum increased
the rate of secreted saliva and its pH (7), Another
important sugar free gum was Acacia gum
consists primarily of Arabica, a complex mixture
of calcium, magnesium and potassium salts of
Arabic acid. It contains tannins which are
reported to exhibit astringent, homeostatic and
healing properties. It also contains cyanogenic
glycosides in addition to several enzymes such as
oxidase, peroxides and pectinases, all of which
have been shown to exhibit antimicrobial
properties. Acacia Arabica type of chewing gum
has potential to inhibit early plaque formation (8).
On other hand most chewing gum is sweetened
with sucrose, gum products may increase the
cariogenic load to dietary carbohydrates (9). The
aim of the present study was to investigate the
effect of different chewing gums on the salivary
constituents
including
some
elements
(Magnesium, Calcium, Copper and Zinc), PH and
flow rate.
MATERIAL AND METHODS
The sample of present study composed 80 dental
students (college of dentistry, university of
Baghdad) aged 23 years, they were divided in to
four groups, each group consist of 20 sample, The
saliva was collected after taking the medical
Vol. 24(2), 2012
history and any medical problems or any systemic
diseases were excluded. The collection of
stimulated salivary samples was performed under
standard condition following instruction cited by
(10)
, while the collection of unstimulated salivary
samples was performed under standard condition
following instruction cited by Tenovuo and
Lagerlof (11)
First group the individuals were asked to collect
unstimulated saliva. Second group the individual
were asked to chew a piece of Mastic chewing
gum. Third group the individual were asked to
chew a piece of Arabic gum. Fourth group the
individual were asked to chew sugar gum. For
these entire 4 groups the chewing was for one
minute all saliva was removed by expectoration,
chewing was then continued for ten minutes with
the same piece of chewing gum and saliva
collected in a sterile screw capped bottle. Salivary
pH was measured using an electronic pH meter
and flow rate of saliva was expressed as milliliter
per minute (ml/min).The salivary samples were
then taken to the laboratory for biochemical
analysis. Samples were centrifuge by (Gallen
kamp, England) at 3000 rpm for 30 minutes; the
clear supernatant was separated by disposable
micropipette and was divided into 4 portions,
stored at (-20°C) in a deep freeze till being
assessed. Biochemical analysis of four elements
of saliva (Calcium, Magnesium, Copper, Zinc)
were done at the Poisoning Consultation Centre /
specialized surgeries hospital by flame atomic,
using absorption spectrophotometer (Buck
scientific, 210VGP, USA) following standardized
procedure.
1. Determination of Ca++ :Dilute the samples in
four groups with the lanthanum diluents, mix
well and take for measurement of calcium by
atomic
absorption
spectrophotometer
(AAS)10.a hollow cathode lamp specific for
calcium was used at a wave length of
422.7nm.
2. Determination of (Magnesium, Copper, Zinc):
the samples in four groups were diluted with
deionised water mix well and take for
measurement of these elements by atomic
absorption spectrophotometer (AAS)(12).
The data was processed with SPSS 9.0
statistical software. ANOVA (analysis of
variance), LSD test and Student's t-test served
for statistical analyses. The significance level
was set at 95% (P<0.05).
RESULTS
The mean values of salivary pH ,flow rate for
different type of chewing gum stimulation were
shown in table 1that shows highly significant
difference in salivary pH among different type of
chewing gum stimulation ,while the difference
were not significant, concerning flow rate. Further
investigation using L.S.D test revealed that there
is no significant difference between salivary pH,
flow rate with different chewing gum stimulation
Table 2 .The pH of unstimulated saliva was found
in the present study to be 6.8±0556 which was
lower that for stimulated saliva with different type
of chewing gum and this difference were highly
significant for Arabic and sugar chewing gum
(-2.958, -3.039) Table (3), this table also revealed
the salivary flow rate for unstimulated saliva was
lower than for stimulated saliva with different
chewing gum but these difference were not
significant. Table (4) shows that there is highly
significant difference in concentration of Mg, Ca,
Cu among different type of chewing gum, while
salivary Zinc concentration the difference was not
significant..Further investigation using L.S.D test
showed that salivary concentration of Mg, Ca and
Cu were found significantly higher among group
with mastic than Arabic chewing gum stimulation,
while opposite figure found concerning salivary
concentration of Zinc with significant difference.
The L.S.D test also shows that the concentration
of salivary Mg, Ca were highly significant, higher
among group using mastic chewing gum than that
using sugared chewing gum and opposite figure
was found concerning concentration of copper as
its concentration were highly significant ,higher
among group using sugar chewing gum than
group using mastic chewing gum Table 5, this
table also revealed that the only significant
difference was found concentration of salivary
copper where company its concentration between
person using sugar stimulation. Salivary Mg , Ca,
Cu, Zn (mean and SD) among unstimulated and
stimulated saliva were shown in table 6 that show
the mean of salivary Mg, Ca was higher in mastic
chewing gum stimulation than that for
unstimulated saliva and these difference were
highly significant (-7.610, -8.174), also this table
revealed that the mean of salivary Cu was higher
concentration in sugar and mastic
gum
stimulation than that for unstimulated saliva with
highly significant difference(-3.023, -11.071),
while significantly salivary Zn concentration was
higher in Arabic chewing gum than that for
unstimulated saliva(-2.413).
DISCUSSION
Chewing gum use has a longer period of exposure
to the surface of teeth than a dentifrice or mouth
rinse; therefore it can be a useful adjunct for
maintaining oral health, especially if it contains a
therapeutic agent that is effective topically(13).In
Vol. 24(2), 2012
the present study the pH ,flow rate and some
salivary elements of three types of chewing gum
and unstimulated saliva was assessed. The present
study represented that the pH mean of
unstimulated saliva group was found to be lower
than other groups with highly significant
difference, this may be due to that there is a
consequent rise in pH level which reaches a peak
(7.6-7.8) after 3-5 minutes of chewing to a level
above the critical pH and this agree with previous
studies (14,15) Although both sucrose containing
and sugar-free gum stimulate salivary flow (9),the
higher mean of flow rate was found in 3rd
group(sugar chewing gum ) in this study with no
significant difference between groups of chewing
gum and unstimulated saliva, , this may be due to
a combined effect of gustatory stimulation from
the sweetening and flavoring agents and
mechanical stimulation of salivary flow from
chewing (16). Concerning salivary elements the
result showed that Mg and Ca ions significantly
high in mastic gum group comparing with other
groups ,this could be due that the use of chewing
gum increases salivary flow rate and enhances
the protective properties of saliva. Moreover, the
higher concentration of calcium, phosphate, and
hydroxyl ions in such saliva also enhances
remineralization(1,3).Furthermore, saliva maintains
the integrity of the teeth, because ions such as
calcium, phosphate, magnesium, and fluoride can
diffuse into enamel (17), Regarding calcium,
phosphate and zinc ions different previous studies
reported a significant role of these elements in
relation to increase resistant of teeth to dental
caries. Their presence in saliva may enhance
remineralization and increase resistant of the outer
enamel surface to acid dissolution (18,19,23),thus
establishing a natural remineralization
process as these ions increases with increas of
salivary flow rate .In the present study the mean
of Zn ione was significantly high in Arabic gum
group this agree with Al Saadi (20), moreover
Acacia gum consists primarily of Arabica, a
complex mixture of calcium, magnesium and
potassium salts of Arabic acid. It contain tannins
which are reported to exhibit astringent,
homeostatic and healing properties (9).as well as
Zinc and Copper are important for the healthy
periodontal tissue as they effect on the collagen
production (21,22).Finally the results of the present
study support the concept that use o1f chewing
gum especially mastic and Arabic(natural gum)
can enhance the remineralizing potential of the
mouth, probably by stimulating salivary flow
which may lead to rise salivary elements. Since
this is the first study on the effect of different
chewing gums on the some salivary elements also
a necessity to investigate the effectiveness of this
natural product through long-term clinical.
REFERENCES
1. Imfeld T. Chewing gum—facts and $ction: a review
of gum chewing and oral health. Crit Rev Oral Biol
Med 1999; 10:405-19.
2. Cloys LA, Christen AG, Christen JA. The
development and history of chewing gum. Bull Hist
Dent 1992; 40:57-65.
3. Saliva: its role in health and disease. Working Group
10 of the Commission on Oral Health, Research and
Epidemiology (CORE).Int Dent J 1992; 42(4 Suppl
2):287-304. Erratum in: Int Dent J1992; 42:410.
4. Szöke J, Bánóczy J, Proskin HM. Effect of aftermeal
sucrose-free gum-chewing on clinical caries. J Dent
Res 2001; 80(8):1725-9.
5. Aksoy A, Duran N, Koksal F. In vitro and invivo
antimicrobial effects of mastic chewing gum against
Streptococcus mutans and mutans streptococci.Arch
Oral Biol 2006; 51(6): 476-81.
6. Biria M, Malekafzali B, Kamel V. Comparison of the
Effect of Xylitol Gum- and Mastic chewing on the
Remineralization Rate of Caries-like Lesion. Journal
of Dentistry, Tehran University of medical Sciences,
Tehran, Iran 2009; 6(1): 6-10.
7. Arfa M, Bakhtiari S. Effect of chewing mastic gum
and a xylitol chewing gum on the PH and flow rate of
saliva, PhD [thesis]. Tehran: Dentistry Faculty of
Shahid Beheshti University of Medical Sciences;
2003-2004.
8. Gazi M. The finding of antiplaque features in acacia
Arabica type of chewing gum. J Clin Periodontal
1991; 18:75-77.
9. Kahtani D .Chewing gum: Trick or treat? The Saudi
Dental Journal 1999;11(1): 27-34
10. Tenovuo J and Legerlof F. Saliva. In: Thylstup A., and
Fejerskov O. ed. Textbook of Clinical Cariology. 2nd
ed. Munksgaard: Copenhagen; 1996.
11. Tenovuo J, Lagerlof F. Saliva . In Textbook of clinical
cariology etd. By thylstrup A and Fejerskov O. 2nd ed.
Munksgaard, Copenhagen, 1994.p.17-43.
12. Haswell SJ. Atomic absorption spectrometry theory,
design and application.Elservier, Tokyo. 1991.
13. Sanares AM,King MK,Itthagarun A,MingWong
H.Chewing gum as amedium for the delivery of
anticariogenic therapeutic agents: a review. Hong
Kong Dent J 2009; 6:13-22.
14. Jason M. Xylitol chewing gum & dental caries. Int
Dent J 1995; 45:65-76.
15. Al Zaidi WH. Oral Immune Factors and Salivary
Contituents in Relation to Oral Health Status among
Pregnant Women. Ph.D. Thesis, College of Dentistry,
University of Baghdad, 2007.
16. Jensen M. Effect of chewing sorbitol gum & paraffin
on human interproximal plaque pH. Caries Res 1986;
20:503-509.
17. Margolis HC, Moreno EC. Kinetics of hydroxyapatite
dissolutionin acetic, lactic, and phosphoric acid
solutions. Calcif Tissue Int1992; 50:137-43.
18. EL-Samarrai SK. Major and trace elements of
permanent teeth and saliva among a group of
adolescent, in relation to dental caries, gingivitis and
mutans streptococci. A Ph.D. Thesis, College of
Dentistry, University of Baghdad, 2001.
Vol. 24(2), 2012
19. Palmer CA. Nutrition, diet and oral conditions. In:
Primary preventive dentistry. By Harris N.O., Christen
A.G.4th ed. Appleton and Lange 1995.
20. Al-Saadi AA. Oral Health Condition and Salivary
Constituents (Zinc,Copper,Calcium,Iron,Total Protein)
among the selected Overweight Primary School
Children. Msc thesis submitted to the College of
Dentistry, University of Baghdad. 2008
21. Curzon ME, Cutress TW. Trace elements and dental
disease. John wright. PSG Inc. England. 1983, 545,p
107-115.
22. Al- Safi KH. Biochemical, Immunological and Histo
chemical study of Cyclosporine- A induced gingival
enlargementin kidney Transplanted patients. Doctor
thesis submitted to the College of Dentistry,
University of Baghdad. 2007.
23. Jawed M, Shahid SM, Qader SA, Azhar A. Dental
Caries in diabetes mellitus role of salivary flow rate
and minerals. Journal of Diabetes and Its
Complications 2011; 25(3): 183-186. IVSL (Iraq
Virtual Science Library).
Table 1: Salivary pH and flow rate (Mean ± SD) among different chewing gum simulation
Variables
pH
Flow rate
Mastic Gum
Arabic Gum
Suger Gum
Mean SD± Mean SD± Mean SD±
7.100 .458 7.275 .454 7.245 .345
2.910 1.208 2.855 1.234 3.420 1.323
Highly significant p< 0.01
ANOVA
F
Sig
4.464* .006
1.369 .259
Table 2: Salivary magnesium, calcium, copper and zinc (Mean ± SD) among different chewing
gum stimulation
Variables
Magnesium
Calcium
Copper
Zinc
Mastic Gum
Mean
SD±
4.593
2.242
15.200 5.207
53.500 13.869
16.000 9.403
Arabic Gum
Mean SD±
.338
.212
4.580 1.477
25.500 6.863
21.500 8.127
Suger Gum
Mean
SD±
.455
.156
3.190
.748
75.000 10.000
15.500 7.591
ANOVA
F
Sig
62.509* .000
70.657* .000
83.572* .000
2.540
.063
Table 3: LSD test of PH and flow rate among different chewing gum stimulation
pH
Flow rate
Mastic &Arabic Gum
Mean
Sig
-.175
.232
.055
.893
Mastic &Suger Gum
Mean
-.145
-.510
Sig
.322
.216
Arabic &Suger Gum
Mean
.030
-.565
Sig
.837
.171
Table 4: LSD test of salivary electrolytes among different chewing gum stimulation
Magnesium
Calcium
Copper
Zinc
Mastic &Arabic Gum
Mean
4.225*
10.620*
28.000*
-5.500*
Mastic &Suger Gum
Sig
Mean
.000
4.138*
.000
12.010 *
.000
-21.000 *
.037
.500
Highly significant p< 0.01
Sig
.000
.000
.000
.848
Arabic &Suger Gum
Mean
.117
1.390
49.000*
6.000*
Sig
.745
.140
.000
.024
Table 5: Salivary Ph and flow rate among unstimulated saliva and stimulated salivary groups
Variables
pH
Flow rate
Unstimulated
mean
SD
Stimulated
Mean
SD
t-test
1 7.100 .458
-1.861
6.800 .556 2 7.275 .454 -2.958*
3 7.245 .345 -3.039*
1 2.910 1.208
-.716
2.615 1.391 2 2.855 1.243
-.575
3 3.420 1.323 -1.875
*Highly significant p<0.01
Sig
.071
.005
.004
.478
.569
.069
Vol. 24(2), 2012
Table 6: Salivary magnesium, calcium, copper and zinc among unstimulated
groups
Stimulated
Mean
SD
t-test
Sig
1 4.468
2.252
-7.610 .000
Magnesium
.777
.491 2
.338
.212
3.667 .001
3
.455
.156
2.792 .008
1 15.200 5.207
-8.174 .000
Calcium
4.856 2.224 2 4.580
1.477
.452
.654
3 3.190
.748
3.163 .003
1 53.500 13.869 -3.023 .004
Copper
42.500 8.506 2 25.500 6.863
6.955 .000
3 75.500 10.000 -11.071 .000
1 15.150 9.783
.126
.900
Zinc
15.500 7.591 2 21.500 8.127
-2.413 .021
3 15.500 7.591
.000
1.00
1=Mastic, 2=Arabic, 3=Sugar (chewing gum), df =38, Sig<0.005
Variables
Unstimulated
mean
SD
and stimulated
Vol. 24(2), 2012
Dynamic lip to tooth
Dynamic lip to tooth relationship during speech, posed and
spontaneous smile using digital videography
Ali S. Al-khafaji, B.D.S. (1)
Nagham M. Al-Mothaffar, B.D.S., M.Sc. (2)
ABSTARCT
Background: The human face is a living mirror held out to the world. Natural, marked, painted or adorned, it has
power to attract, charm, captivate or brighten. Therefore the subject of the smile and facial animation, as they
relate to communication and expression of emotion, should be of great interest to orthodontists so the aims of this
study were to determine the difference of outer commissure width, inter-labial gap, smile index, modified smile index,
visible maxillary interdental width, buccal corridor percentage and maximum incisor show among different smile
styles (Monalisa, Cuspid and complex) during emotion, posed smile and speech. And to determine the differences of
the same variables for each smile style among emotional smile, posed smile and speech.
Materials and methods: The sample consisted of 77 Iraqi adult subjects (18-30) years with skeletal class I occlusion,
classified into three categories according to a certain neuromuscular mechanism of smile called smile style, the first
group consisted of 34 (24 male, 10 female) subjects with Monalisa smile style, the second consisted of 34 (22 male, 12
female) subjects with Cuspid smile style, the last 9 subjects (5 male, 4 female) were the third group with Complex
smile style. Each subject was recorded using digital videographic camera while watching a comical movie to elicit
emotional smile, then they asked to say “Chelsea eats cheesecake” to record them during speech. The videographs
were imported to the PMB-picture motion browser to capture emotional smile, posed smile and speech frames. Four
linear measurements were measured for each frame using AutoCAD program 2011.
Results: The results of this study showed that all the variables changed significantly when the subject change from
speech to emotional smile frame in all smile styles. And these changes revealed almost the same behavior when the
subject changed from speech to pose or to emotional smile frames.
Conclusion: The result of this study revealed that emotional smile is largely different from posed smile in different
aspects which has an effect on decisions related to orthodontic diagnosis and treatment plan.
Keywords: smile style, emotional smile, posed smile, digital videography. (J Bagh Coll Dentistry 2012;24(2):99-103).
INTRODUCTION
Obtaining a beautiful smile is always the main
objective of any aesthetic dental treatment.
Therefore, it is essential to control the esthetic
effects caused by orthodontic treatment, which is
only possible by knowing the principles that
manage the balance between teeth and soft tissues
during smile (1); as the presence of a malocclusion
has a negative impact on facial attractiveness and
orthodontic correction of a malocclusion affects
overall facial esthetics positively (2). After all, it is
the beauty of the smile that will make the
difference between an acceptable or pleasing
aesthetic result for any given treatment (3).Smiles
can be either posed or spontaneous (4), the posed,
false, or social smile which is voluntarysmile and
does not need an emotion to be accomplished. A
posed smile is static in the sense that it can be
sustained (5). When posing for a photograph a
person uses the social smile in social setting (6). In
treating the smile, the social smile generally
represents a repeatable smile (7). However, the
social smile can mature and might not be
consistent over time in some patients (8).
(1) M.Sc. student, dep. of Orthodontics, college of dentistry,
university of Baghdad
(2) Professor, dep. of Orthodontics, college of dentistry,
university of Baghdad
The unposed, spontaneous, enjoyment or real
smile is involuntary and represents the emotion
that persons are experiencing at that moment.
Therefore it has many descriptions, such as
laughing, cry, knowing or insipid (9). It is dynamic
in the sense that it bursts forth but is not
sustained.Emotional backgrounds influence a
voluntary posed smile (10), A well-known
phenomenon in clinical practice is that patients
guard their smiles because of dissatisfaction with
them. When asked for a posed smile, they show
only what they consciously or subconsciously
want to present (11).Another example of interfering
emotional factors on the posed smile is feelings of
shame by victims of undisclosed childhood sexual
abuse. Their social smiles appeared to be
considerably less expressive; sospontaneous
smiling is a logical focus point in smile
diagnostics (12). This is in line with
recommendations of oral surgeons and esthetic
dentists (13) .Smile style is another soft-tissue
determinant of the dynamic display zone. There
are three styles: the cuspid smile, the complex
smile, and the Mona Lisa smile. An individual’s
smile style depends on the direction of elevation
and depression of the lips and the predominant
muscle groups involved. The cuspid or
commissure smile is characterized by the action of
Vol. 24(2), 2012
all the elevators of the upper lip, raising it like a
window shade to expose the teeth and gingival
scaffold. The complex or full-denture smile is
characterized by the action of the elevators of the
upper lip and the depressors of the lower lip
acting simultaneously, raising the upper lip like a
window shade and lowering the lower lip like a
window. The Mona Lisa smile is characterized by
the action of the zygomaticus major muscles,
drawing the outer commissures outward and
upward, followed by a gradual elevation of the
upper lip. Patients with complex smiles tend to
display more teeth and gingiva than patients with
Mona Lisa smiles (14).
The sample of the study composed of 77 Iraqi
adult subjects in an age group of 18-30 years with
skeletal class I occlusion.The sample was
classified into three groups according to smile
style as the following:Monalisa group composed
of 34 subjects (24 male and 10 female), Complex
group composed of 9 subjects (5 male and 4
female), Cuspid group composed of 34 subjects
(22 male and 12 female).This classification was
done depending on the direction of elevationand
depression of the lips and the predominant muscle
groups involved.The video recordings for each
group were made in a setup consisting of a chair
with a digital video camera and television set
(laptop connected to the screen). The television
screen was placed at eye level. When the visual
axis will be horizontal, the subjects will keep their
heads mainly in a natural head position(15). The
video camera was adjusted to the subject’s mouth
level at a 55-cm distance and continuously
registering the face as shown in figure 1.
To prompt emotional smiling, the subjects
watched television fragments of practical jokes
downloaded from the website of videos “you
tube” the funniest Iraqi practical jokes. The
subjects will be unaware of the exact aim of the
study. While watching the television, the subjects
wear glasses with a clipped-on reference standard
to enable calibration in a digital measurement
program. In this way, a maximum emotional smile
(emotional smile frame) will be recorded with
minimal intrusion of the subject (16).By using the
same technique for obtaining natural head
position in emotional smile capture, the subject
was asked to read a sentence appeared on the
screen made by a power point slide, this sentence
was “Chelsea eats cheesecake” to capture him\her
saying the syllable “chee” (speech frame). The
subject was asked to relax, and then smile to
capture the posed smile (posed smile
frame).Firstly, the videographs were imported to
the PMB- picture motion browser. This software
enables the operator to save a movie as an image
sequence and then export roughly 24 frames per
second. Each frame could be saved identical in
size and resolution (17).To extract frame from
video recording of speech, a video converter
computer software was used to split the second in
which the subject saying the syllable “chee” in the
word “cheesecake” into 30 frames or more in
persons who pronounced the word very fast.In
addition to high quality video recording mode
(HQ MODE) the photos (frames) extracted from
the video clips were treated with another software
which was the “photozoom pro 3” to improve
image quality while zooming in AutoCAD
program 2011. Finally, smile frame was imported
to the AutoCAD program. Magnification
correction was done in reference to the glasses
with the attached ruler, so that the real
measurements were obtained. After that,
landmarks were identified and measurements
were determined (Figure 2).
Figure 1: Standardization of the videogragh
Figure 2: Linear measurements during
emotional smile
Vol. 24(2), 2012
RESULTS
The sample is classified into three groups, each
group captured in three frames: speech, posed and
emotional smile frames.Comparison among
different smile styles for each frame is done first,
to compare among different smile style during
emotional smile,analysis of variance (ANOVA
test) was performed to identify the presence of
significant differences for the measured variables.
As shown below (Table 1) there was a significant
difference in all the variables measured except for
outer commissure width.
Table 1: ANOVA test for emotional smile
among different smile style.
Variable
OCW
ILG
SI
MSI
VIW
BCP
MIS
F
0.320
12.45
13.90
12.47
21.66
30.89
3.657
p-value
0.727
.000
.000
.000
.000
.000
0.03
Sig
Ns
***
***
***
***
***
**
The LSD test (Table 2) was used to detect
statistically significant difference between every
two groups for the significant different variable
found in ANOVA test (Table 1), Interlabial gap
(ILG) and modified smile index (MSI) were
significantly higher in Cuspid group when
compared with Monalisa and Complex groups,
while smile index (SI), visible intermaxillary
width (VIW) and buccal corridor percentage
(BCP) was significantly higher in Monalisa and
Complex groups than in Cuspid group.
Table 2: LSD for emotional smile frame
among different smile style
Var.
SMILE STYLE
P
SIG
Monalisa Cuspid
.000
***
ILG Monalisa Complex
.635
NS
Cuspid
Complex
.009
*
Monalisa Cuspid
.000
***
SI
Monalisa Complex
.846
NS
Cuspid
Complex
.003
**
Monalisa Cuspid
.000
***
MSI Monalisa Complex
.894
NS
Cuspid
Complex
.002
**
Monalisa Cuspid
.000
***
VIW Monalisa Complex
.465
NS
Cuspid
Complex
.000
***
Monalisa Cuspid
.000
***
BCP Monalisa Complex
.946
NS
Cuspid
Complex
.000
***
Monalisa Cuspid
.052
NS
MIS Monalisa Complex
.273
NS
Cuspid
Complex
.020
*
Finally maximum incisor show (MIS) was only
significantly higher in Cuspid group than
Complex group, but insignificantly higher in
Monalisa than Complex group.
The same method is used to compare among
different smile styles in speech and posed smile
frames. Comparison among different frames for
each smile style is also done by ANOVA test for
Monalisa group in different frames (emotional,
posed, and speech frame) as revealed in Table 3.
Table 3: ANOVA test for Monalisa group in
different frames
Variable
OCW
ILG
SI
MSI
VIW
BCP
MIS
F
20.94
45.87
11.88
12.65
80.08
32.68
30.89
p-value
.000
.000
.000
.000
.000
.000
.000
Sig
***
***
***
***
***
***
***
The LSD test revealed that all variables shows
significant difference between every two frames
except for smile index (SI) and modified smile
index (MSI) between posed smile and speech
which were insignificantly differ from each other.
Again the same statistical analysis is used to
compare the other smile styles (Cuspid and
Complex) in different frames.
DISCUSSION
The age of the sample ranged from 18 to 30 years
because adolescents undergo a maturational
sequence in learning how to smile (18) and on the
other hand all dynamic measurements of the smile
decrease with age especially after ages 30 to 39
years (19). In addition in this study, there was no
need to differentiate between genders (16). Firstly,
Emotional smile in each smile style:the Interlabial
gap (ILG) was significantly higher in Cuspid
group than Monalisa and Complex groups, this
increase may be due to the dominance of the
levatorlabiisuperioris musclein Cuspid group
exposing more attached gingivae above the
maxillary anterior teeth than the other groups and
thus increasing Interlabial gap this comes in
agreement with the explanation of Phillips in
1999.The same reason mentioned above was
responsible for significant increase in modified
smile index (MSI) and decreased smile index (SI)
for Cuspid group over the other groups because
they depend on Interlabial gap (ILG). This come
in agreement with Ackerman and Ackerman
(2002); Sarver and Ackerman (2003b) who found
Vol. 24(2), 2012
any increase in interlabial gap leads to decrease in
smile index and any increase in outer commissure
width leads to increase smile index.
For visible maxillary interdental width (VIW) of
Complex group showed statistical significant
increase from Cuspid and statistical nonsignificant increase from Monalisa groups, this
may be due to the fact that in Complex group the
shape of the lips are typically illustrated as two
parallel chevrons, the levators of the upper lip, the
levators of the corners of the mouth, and the
depressors of the lower lip contract
simultaneously, showing all the upper and lower
teeth concurrently showing more area of upper
teeth than the other groups, this comes in line with
the conclusion Phillips 1999.For buccal corridor
percentage (BCP) the same explanation can be
given to significant increase of Complex group
compared with Cuspid group because buccal
corridor percentage (BCP) depends on visible
maxillary interdental width (VIW).Finally the
Cuspid group showed significant increase in
maximum incisor show (MIS) than Complex
group, also may be due to that the vertical
distance between upper left central incisor incisal
edge and upper lip margin increased, this comes
in agreement with the findings of Phillips in
1999(20), who reported that the maximum incisor
show increased in Cuspid group.
Speech in each smile style had a different liptooth characteristics, Although the main muscle
responsible for the morphological change in lips
during saying “cheese” is the orbicularis oris
muscle, it may be affected by the specific
neuromuscular mechanism of each smile style
because the levatorlabiisuperiorus muscle have
the medial slip inserted into the orbicularis oris
muscle(21). Also in a study of electromyography
(EMG) of human lip muscle done by Blair and
Smith (22), they found that even with intramuscular
electrodes, the probability of recording from a
single muscle of the lip during speech is
extremely low. So the interaction of muscle of
facial expression during speech could explain why
even with speech each smile style have different
lip-tooth relationships.The explanations of
significant increase or decrease of different
variable during speech among different smile
styles may resemble those of emotional or posed
smile patterns probably because of interfering
facial muscle as discussed above.
Monalisa smile style in each frame: Firstly the
outer commissure width (OCW) was greater with
highly significant level in emotional smile than
posed one, this finding supports the conclusion of
Van der Geld et al. in 2008(23)who noticed the
significant reduction in inter-commissure distance
(smile width) of posed smiling compared to
emotional smiling.The statistical significant
increase of interlabial gap (ILG) of emotional
smile over posed one may result from mouth
opening and increase in the mandibular anterior
tooth display during emotional smile.The
statistical significant decrease of interlabial gap
(ILG) of speech when compared with posed smile
comes in disagreement with Ackerman et al. in
2004 who found insignificant increase of
Interlabial gap (ILG) of speech when compared
with posed smile.The statistical significant
increase of visible maxillary interdental width
(VIW) of emotional smile when compared with
other frames may be as a result of exposing the
2nd premolar and 1st molar during emotional
smiling than during posed smiling.
The result of this study revealed that emotional
smile is largely different from posed smile in
different aspects which has an effect on decisions
related to orthodontic diagnosis and treatment
plan.The outer commissure width and visible
maxillary interdental width that compose the
buccal corridor percentage, as we know the
smaller the buccal corridor the greater the esthetic
appearance, and in posed smile the buccal
corridor is significantly lower than in emotional
smile, so the dependence on buccal corridor
percentage (BCP) of posed smile can lead to
inadequate diagnosis and treatment plan regarding
arch width, smile arc and transversal occlusal
plane.This comes in agreement with Van der Geld
et al., in 2008who stated that as a result of
reduced smile width during posed smiling, the
buccal corridors can be underestimated and upper
arch widening not deemed to be needed during
orthodontic or surgical treatment.The maximum
incisor show was significantly higher in emotional
smile than posed, in another words the lip line
height is appeared too low in posed smile
particularly in the case of gummy smile patients,
who have the muscular ability to raise the upper
lip significantly higher than average on smiling
emotionally. Again it was the posed smile smaller
measurement that may give us the errors in
estimation of gummy smile, and subsequently
decisions of intrusion of maxillary anterior teeth
versus surgical intervention to correct the problem
becomes a matter of controversy.
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2. Rodrigues CD, Magnani R, Machado MS, Oliveira
OB. The Perception of Smile Attractiveness. Angle
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Vol. 24(2), 2012
Dental caries in
Dental caries in relation to oral infections and feeding
types among children aged 2-5 years
Aseel H. M.J. Al-Assadi, B.D.S., M.Sc. (1)
ABSTRACT
Background: Dental caries is an infectious and transmissible disease that still represents as a significant public health
problems in many countries. The aim of this study was to investigate the relation between dental caries and oral
infections (tonsillitis and candidiasis) as well as the relation to feeding type.
Material and methods: The study sample composed of 22 healthy children aged 2-5 years with full set of primary
dentition and had dental caries. The control group composed of 22 caries free children matching the study group in
age and gender. An information sheet from the parents was done to all children concerning general health, feeding
habits and frequency of oral infections (tonsillitis and oral thrush) during the last year. Children were examined
clinically using dmft index, oral microorganisms was sampled and cultured aerobically using blood agar, MacConkey
agar, chocolate agar and sabauraud,s dextrose agar.
Results: Children with dental caries were mostly bottle fed and showed higher frequency of continuous oral
infections. Regarding dental caries there were highly significant relations between caries activity and method of
feeding and types of microorganisms found in the oral cavity , also a highly significant relation was found between
method of feeding and frequency of oral infections. Children with dental caries had more types of oral
microorganisms compared to caries free children Candida, Strep.pyogenes, Strep. viridans, Strep.faecalis,
Strep.pneumonia, Staph.aureus, E.coli, Enterobacter ,Acinetobacter and Pseudomonas were found in high
frequency among caries active children.
Conclusion: Types of microorganisms found in the oral cavity was affected by dental caries which in turn affect
frequency of infections. Breast feeding was predominant among caries free children and associated with lower rates
of oral infections compared with bottle feeding so public should informed about its long term effect on the general
health.
Keywords: Dental caries, tonsillitis, candidal infections, breast feeding. (J Bagh Coll Dentistry 2012;24(2):104-108).
INTRODUCTION
Dental caries is one of the most prevalent
chronic disease(1) commonly affect children(2),it
still holds the highest prevalence and severity
among other dental problems. The caries process
can develop as soon as the tooth erupted in the
oral cavity(3).It is regarded as an infectious,
contagious and multifactorial disease produced by
three primary individual factors: cariogenic
microorganisms, cariogenic substrate and
susceptible host (or tooth)(4). These factors
interact in a certain period of time causing an
imbalance in the demineralization and
remineralization between tooth surface and the
adjacent plaque (5).
The oral cavity of neonates is germ free or
contains the same microorganisms of the vagina,
which will decrease in number few days after
birth and will be readily changed by child
caretaker microorganisms(6) . Thus the cariogenic
microorganisms can be transmitted to the infant
and caries development may be favored (7), that
transmission may be vertical transmission from
caregiver to child and the major reservoir from
which infants acquire those microorganisms is
their mothers (8,9) or the horizontal transmission
(between members of a group e.g. family
members of a similar age or students in a
classroom) (10).
(1)Lecturer, Department of Pedodontics and Preventive Dentistry,
The most important factor in the determination
of child medical and dental health is the family.
This may be due to the fact that family, especially
the mother, greatly influences the health related
behavior of the child (11,12). Most of mothers had
very little knowledge on how important breast
milk is for a child’s health and, till now, the
delivery of formula milk is expected to replace the
role of breast milk providing nutrition for infants
which contains very high sugar and low on other
nutrition elements (3). Concerning infants feeding
methods, prolonged and exclusive breast-feeding
has been associated with many health benefits,
including reduced risks of gastrointestinal and
respiratory infection, atopic eczema and other
allergic diseases, and improved neurocognitive
development(13), while bottle fed children are
more prone to frequent infections such as oral
thrush, acute otitis media and upper respiratory
tract infections(14).There are many studies found
that bottle fed children are more likely to develop
dental caries than their breast fed counterparts (1518)
,but others found no significant relation(8,19) .
Oral health is one component of general health
and is an important factor in the normal
development of a child. Oral health problems or
illnesses can influence the general development of
a child and its general health and can adversely
affect quality of life (20).
However, there is no available previous Iraqi
study concerning the relation between dental
Vol. 24(2), 2012
Dental caries in
caries and oral infections. So this study was an
attempt to determine this relation according to
feeding habits and types of microorganisms found
in the oral cavity among group of children aged 25 year old.
Statistical analyses were performed using
SPSS package version 16. Student’s t-test was
applied for comparisons between the caries free
and caries active group. (P < 0.05) was considered
statistically significant.
MATERIAL AND METHODS
RESULTS
Twenty two children with no history of any
systemic diseases aged 2-5 years were
participated in the present study (study group). All
of them were with full set of primary dentition
and had dental caries. The control group
composed of 22 caries free children matching the
study group in age and gender. A consent form
obtained from the parents and an information
sheet filled by interview with them concerning
general health, feeding habits and frequency of
oral infections (tonsillitis and oral thrush) of their
children. Exclusion criteria were antibiotic and ⁄or
antimycotic treatment in the previous three
months at least and the presence of chronic
disease, then the children were examined
clinically using WHO criteria and the index
recorded as dmft (21).
Microbiological samples were obtained from
children by swapping their mucosal surface of the
cheek, hard palate, dorsum of the tongue and floor
of the mouth with sterile cotton swap (22) .All
these swaps cultured aerobically. Each swap
streaked on blood agar, MacConkey agar,
chocolate agar and sabauraud,s dextrose agar then
incubated aerobically for 24 hours at 370 C(23) .
The morphology of different types of colonies
was recorded and smears of these different
colonies were done to study the Gram's reaction
and microscopical characteristic (24).
Different types of colonies were sub cultured
and stored for further biochemical tests to reach
complete identification of each isolate. These tests
include: 1. Hemolysis on blood and choclate agar plates
(25)
.
2. Differential and selective culture media:
MacConkey's agar to observe lactose and non
– lactose fermenter colonies (Oxoid, England),
Sabauraud's dextrose agar (Difco, USA) and
Mannitol salt agar to observe mannitol
fermenter colonies (Difco, USA).
3. Catalase test(24).
4. Oxidase test.
5. Slide Coagulase test(26).
6. Imvic(24)
7. Urease test (24) .
8. Kliger iron agar (KIA) test (27).
9. Bacitracin differentiation test (28).
10. Optochin sensitivity test (27).
Children affected by tonsillitis continuously
were more among caries active children (75%),
while those affected by tonsillitis occasionally
were (68.75%) caries free. There was no
association between caries activity and frequency
of tonsillitis. Concerning candidal infection,
children affected continuously were more among
caries active children 77.78%, while those
affected few and distant times with candidiasis
were more among caries free children 70.83%
(Table 1). Significant association was found
between caries activity and frequency of candidal
infections (X2=9.217, P<0.01).
There are 13 different types of microorganisms
among caries active children, while in those with
caries free children there were only 10 different
types of microorganisms (Table 2). In caries
active children, the highest percentage was
appeared to be found for Strept.viridans,
Moraxella, Candida, Strep. Pyogenes ( 100%,
95.45%, 86.36% and 72.73% respectively),
however, in caries free children the highest
percentage was appeared to be found for
Strept.viridans and
Moraxella, followed by
Staph. Epidermidis and then Candida. Highly
significant association was found between caries
activity and types of microorganisms (X2=33.364,
P<0.01).
A comparison between caries active and caries
free children by method of feeding was shown in
Table 3, it was found that most of caries active
children were fed by bottle feeding method
(72.73%), while those with caries free were fed by
breast feeding method(72.73%). Statistically,
there was an association between caries activity
and method of feeding.
Table(4) reveals that only (8.33%) breast fed
children and (83.33%) bottle fed children were
affected continuously by tonsillitis; continuous
infection was more among bottle fed children than
breast fed children. On the other hand, all those
with continuous candidal infections were feeding
by bottle feeding method, while neither the breast
nor the mixed fed children were affected
continuously by candidiasis. Highly significant
association was found between feeding method
and frequency of infections regarding tonsillitis
and candidiasis (P<0.01).
Vol. 24(2), 2012
DISCUSSION
Although oral infections are usually not life
threatening, it should be remembered that oral
health is one of the most important part of the
general body health. It is well documented that
dental caries is the most prevalent oral disease
among children and young adults(29) and also it is
considered as a public health problem(30).
According to some studies(31,32,33) the immune
system of the oral cavity and the regulation the
oral microflora is considered as very important in
caries pathogenesis and that formation of immune
system of the oral cavity to a great extent depend
on the regional lymphoid organs and main role
belongs to laryngeal and pharyngeal tonsils,
(Tonsils are considered as lymphoid organs,
providing oral cavity by immunoglobulins in
cooperation with salivary glands, consequently it
is supposed that tonsils play an essential role in
suppression of cariogenic microflora, thereby
providing caries prophylaxis or vice versa) (34).
The percentage of caries active children affected
by tonsillitis and candidiasis continuously was
higher than that of caries free children and this
could be due to the significant changes in the oral
ecosystem that was detected between the caries
active and caries free children that may attributed
to the difference between the two groups.
Present microbial investigations has shown
that the predominant bacterial isolates which had
been found in both caries active and caries free
children were Strep.viridans and Moraxella.
These two microorganisms are normal flora in the
mouth and the presence of Moraxella in this high
percentage is in agreement with other studies
(16,35)
.
The correlation between high prevalence of
candidal species in dental plaque and saliva and
the development of active caries lesions is
supported by many studies( 34,36,37,38) ,as well as the
present study that showed the next most common
microbial isolates among caries active children
was Candida (86.36%) compared to (9.09%) in
caries free children and this can explain the higher
frequency of continuous candidal infections
among caries active children. Strep.pyogenes is a
β-haemolytic, it is one of the commonest bacterial
pathogens that cause pharyngotonsilitis all over
the world (39). In the present study, Strep.pyogenes
Dental caries in
found in less frequency in caries free children
which is in agreement with Nolte(35) who reported
that these microorganisms are not commonly
found in the oral cavity. On the other hand, Sterp.
pyogenes isolates represents (72.73%) in caries
active children, this higher percentage may be due
to a positive correlation which was found between
the presence of Strep.pyogenes in oral cavity of
children and dental caries (35), and this is true
concerning the present study and this higher
percentage can support the higher frequency of
continuous tonsillitis among caries active
children, this was in agreement with Kipiani study
(33)
.
In the present study, caries active children
were mostly fed by bottle feeding method,
however, breast feeding was the predominant
feeding method among caries free children and
this was similar to previous studies (3,15-18) this
could be due to the fact that human breast milk
have buffer capacity that eventually able to
prevent caries (3,9) and it contains caries protective
elements such as maternal immunoglobulin’s,
enzymes, leucocytes and specific antibacterial
agents (40-42) , in addition to that cariogenic
bacteria may not be able to utilize lactose as an
energy source as readily as sucrose (43) and
Streptococcus mutans is highly susceptible to the
bactericidal action of lactoferrin (which is found
in the breast milk) that chelates iron, making this
essential nutrient inaccessible to an invading
microorganisms (44).
So as a conclusion, oral infections (tonsillitis
and candidiasis) are frequently occur among
children with dental caries, therefore, health
education for parents and children to improve
their knowledge concerning the effects of dental
caries and oral infections should be planned and
carried out skillfully throughout specified
community health programs. Young nursing
mothers should be advised and encouraged about
the beneficial effects of breast feeding for the
child’s health since that it contains a lot of high
quality nutrition to enhance the immune system,
also contains other elements that have protective
effects against caries process, while bottle feeding
contain very high sugar and low on other nutrition
elements, if it is delivered in a wrong way it can
caused caries.
Vol. 24(2), 2012
Dental caries in
Table 1: Frequency of oral infection occurrence among caries active and caries free children
Variables
Tonsillitis
Candidal
infection
Frequency of infection
Continuously
Occasionally
Few and distant times
Continuously
Occasionally
Caries active
9(75.00%)
5(31.25%)
8(50.00%)
7(77.78%)
8(72.73%)
7(29.16%)
Caries free
3(25.00%)
11(68.75%)
8(50%)
2(22.22%)
3(27.27%)
17(70.83%)
Total
12
16
16
9
11
24
X2
N.S.
9.217 *
*Highly significant, P<0.01, df = 2
Table 2: Distribution of caries active and caries free children according to the types of microorganisms
Type of
micro-organisms
Strep.viridans
Strep.faecalis
Strep.pyogen
Strep.pneumonia
Moraxella
Candida
Staph.aureus
Staph.epi.
E.coli
Acinetobacter
Enterobacter
Pseudomonas
Klebsiella
Caries active
Caries free
X2
22
14
16
1
21
19
6
15
6
5
3
1
1
22
1
1
0
22
2
1
7
1
2
0
0
1
33.364*
*Highly significant, P<0.01, df=12
Table 3: Distribution of caries active and caries free children according to methods of feeding
Feeding method
Breast feeding
Bottle feeding
Mixed feeding
Total
Caries active
1 (4.55%)
16(72.73%)
5(22.73%)
22
Caries free
16(72.73%)
2 (9.09%)
4(18.18%)
22
X2
24.235*
*Highly significant, P < 0.01, df= 2
Table 4: Occurrence of oral infections by method of feeding
Variables
Tonsillitis
Candidal
infection
Frequency of infection
Continuously
Occasionally
Continuously
Occasionally
Breast feeding
1(8.33%)
9(56.25%)
7(43.75%)
0(0.00%)
4(36.36%)
13(54.17%)
Bottle feeding
10(83.33%)
2(12.50%)
6(37.50%)
9(100.00%)
6(54.54%)
3(12.50%)
Mixed feeding
1(8.33%)
5(31.25%)
3(18.75%)
0(0.00%)
1(9.09%)
8(33.33%)
Total
12
16
16
9
11
24
X2
14.523*
22.388*
*Highly significant, P < 0.01,df = 4
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Vol. 24(2), 2012
The staining effect
The staining effect of chlorhexidine mouthwash on non
metallic brackets (An in vitro comparative study)
Hayder J. Attar, B.D.S., M.Sc.
Fakhri A. Ali, B.D.S., M.Sc. (2)
(1)
ABSTRACT
Background: Since it is needed to have means other than mechanical plaque control to achieve good oral hygiene
in orthodontic patients, and since an eliminating the metallic appearance of orthodontic appliance is always
desired to achieve a maximum esthetic appliance, so this study was done to investigate and compare the staining
effects of chlorhexidine mouthwash 0.2% on the un bonded ceramic brackets, ceramic brackets bonded with no
mix adhesive, ceramic brackets bonded with light cured adhesive, un bonded composite brackets, composite
brackets bonded with no mix adhesive and composite brackets bonded with light cured adhesive.
Materials and Methods: The effect of the chlorhexidine was studied through immersion the brackets and bonded
brackets in the mouth wash for three different time intervals: 1, 2 and 3 hours, which represent the accumulated daily
use of the mouthwash for 1, 2, and 3 months respectively and compared them with corresponding control groups
which not immersed in chlorhexidine 0.2%. The sample consisted of two hundred eighty eight brackets. AShimadzu,
UV 160A UV-Visible spectrophotometer was used to perform a light absorption test for each subgroup with twelve
brackets each.
Results: ANOVA and LSD post Hoc tests were used to identify the significant effects of the mouthwash at a
significance level P ≤ 0.05, ِA significant effects identified with ceramic brackets bonded with no mix adhesive,
ceramic brackets bonded with light cured adhesive, un bonded composite brackets, composite brackets bonded
with no mix adhesive and composite brackets bonded with light cured adhesive, while non significant effect of un
bonded ceramic brackets.
Conclusions: It can be concluded that the chlorhexidine mouthwash do not have a staining effect on the un
bonded ceramic brackets while significant changes in staining effect when ceramic and composite brackets
bonded to no mix adhesives and that effect decrease when bonded to light cured adhesives. The mouthwash has a
staining effect on the un bonded composite brackets also.
Key words: Ceramic bracket, composite bracket, chlorhexidine. (J Bagh Coll Dentistry 2012;24(2):109-113).
INTRODUCTION
The esthetic requirements of orthodontic
treatment prompted the development of toothcolored brackets as alternatives to metal brackets
(1)
. Many types of nonmetallic brackets fabricated
from alumina and zirconia ceramics, as well as a
variety of plastic brackets and composite brackets
had been introduced during the past decades (2)
Some of the earliest applications of chlorhexidine
for the control of plaque and gingivitis go back to
1970s, when the dental literature reported on the
use of 0.2% chlorhexidine gluconate rinses; twice
a day; to prevent plaque accumulation and
subsequent gingivitis (3). The adequate plaque
control was difficult in patients undergoing
orthodontic treatment, especially in the cases of
children and adolescents and when bands and
auxiliaries were involved (4). Many researchers
classified staining as either extrinsic or intrinsic (5,
6)
.There was confusion concerning the exact
definitions of these terms. Feinman et al (7)
described extrinsic discoloration as occurring
when an agent stains or damage the enamel
surface of teeth and intrinsic staining as occurring
(1)M.Sc. student, Department of Orthodontics, College of
(2)Professor, Department of Orthodontics, College of Dentistry,
University of Baghdad
when internal structure is penetrated by a
discoloring agent; according to his definition; the
term staining and discoloration were used
synonymously. However; extrinsic staining
defined as staining that could be easily removed
by normal prophylactic cleaning, intrinsic staining
was defined as endogenous discoloration that had
been incorporated in to the structure matrix and
thus could not be removed by prophylaxis (8). The
etiology of the dental discoloration is
multifactorial in which different part of the tooth
could take up different stains (9).
Mouth wash containing chlorhexidine caused
superficial black and brown staining of the teeth
(10, 11)
. Ceramic brackets are more esthetic than
metal brackets, and unlike plastic or composite
brackets, they resisted staining and discoloration
(12)
Orthodontic adhesives could have intrinsic and
extrinsic discoloration, chlorhexidine could
discolor composite extrinsically and with time
become intrinsically throughout a resin matrix,
which was usually attributable to chemical
degeneration of the filler–resin bond and
solubility of the resin matrix (13).
Vol. 24(2), 2012
MATERIALS AND METHOD
Two types of brackets were used in this study,
they were of standard edgewise (22×30 slot
dimension), and with horizontal grooves in the
base of bracket to generate a macro-retention
undercuts to achieve maximum mechanical
bonding surface. They include:
Reflections® ceramic brackets which was made
from 99.9% pure polycrystalline alumina, Rave®
composite brackets were made from Injection
Molded High Quality Reinforced Composite to
increase bracket body strength with precise slot
dimensions(Ortho Technology/U.S.A.(
Resilience® No-Mix orthodontic adhesive,
Resilience Primer®, Resilience® Light-Cure
orthodontic adhesive, Resilience light cure
Primer®(OrthoTechnology/U.S.A.) were used for
bonding .
Corsodyl® Chlorhexidine digluconate 0.2% W\V,
(GlaxoSmithKline, UK) was used as a test
immersion media in the study.
Bonding procedure:
The sample composed of 144 Reflections®
ceramic brackets and 144 Rave® composite
brackets, the brackets were divided according to
bond material into three groups of 48 brackets:
• Un bonded brackets which were not bonded to
any bond materials.
• Chemically cured bonded brackets in which
the brackets were bonded using chemically
cured adhesive resin.
• Light cured bonded brackets in which the
brackets were bonded using light cured
adhesive resin.
The ceramic and composite brackets were
bonded with a chemically cured, light-cured
orthodontic adhesive as follow:
• Resilience Primer® was applied by brush on
each bracket base or Resilience light cure
Primer® used with Resilience® Light-Cure
orthodontic adhesive .
• A small amount of the adhesive paste was
applied onto the bracket base, and then by
using a clamping tweezer the bracket was
placed lightly onto a horizontal flat plastic
plate mounted on the table of surveyor(Dent
aurum, Germany) covered by a celluloid strip
to facilitate detachment of the bracket–
adhesive complex with a recovery of the set
material.
• A constant load of two hundred grams was
placed on the bracket to ensure a uniform
thickness of the adhesive, the load fixed to the
upper part of the vertical arm of the surveyor,
a surveyor rod was fixed in the lower part of
the vertical arm of the surveyor and put it in
contact with the bonded bracket, excess
The staining effect
adhesive was removed from around the
bracket base with a sharp scalar (Bishara et al,
2005)
• The visible light-cured adhesive specimens
were photopolymerized with a light-curing
unit (YDL/ Hangzhou Yinya Co.,China); the
light guide of curing light unit was directed
toward the bracket, the light shined through
the bracket for 20 second (according to
manufacturer instruction .(The bonded
brackets were allowed to bench set for 24 hr to
ensure complete polymerization of adhesive
material, then after setting; the celluloid strips
were removed and the resultant bracketbonded adhesive were flat.
Immersion in chlorhexidine:
Un bonded and bonded brackets were farther
subdivided according to time interval immersion
in chlorhexidine 0.2% into four groups with 12
brackets each which include 1 hour,2 hours ,3
hours immersion in chlorhexidine and one control
group which not immersed in chlorhexidine. Then
the immersion procedure was done by positioned
each bracket on a black rectangular cardboard
(35×45×0.2 mm) with central window, the
cardboards were numbered and using the number
of the card as a reference .The specimens then
immersed in Chlorhexidine 0.2% solution
contained in inert plastic containers. Immersion
was done according to the different time intervals
for one, two, and three hours in Chlorhexidine
gluconate mouth rinse 0.2% at 37˚с in the
incubator
Assessment of staining :
The samples were taken out of the immersion
media; then Staining measurements were
performed over the 800 to 200 ŋm visible
wavelength
range
with
UV-Visible
spectrophotometer (Shimadzu; UV160A; Japan.(
The chamber of the spectrophotometer was
opened, and then the black rectangular cardboard
with bracket positioned in central window was
used to position the bracket in the front part of the
analytical beam holder of spectrophotometer,
Then the chamber was closed and the machine
was given the order to start scanning starting from
800ŋm wavelength in the infra-red zone to 200ŋm
wavelength in the UV zone passing through the
entire visible spectrum .
The light passes through the sample; then the
intensity of the remaining light was measured
with a light sensor, the results appeared as a graph
from which the amount of light absorption was
plotted and the amount of absorbed light at a
345ŋm wavelength visible light was obtained and
used in the later statistical analysis .
Vol. 24(2), 2012
Statistical analysis
Descriptive statistics: including mean, standard
deviation, and standard error. Inferential statistics:
including: One way analysis of variance
(ANOVA) to test any statistically significant
difference among the light absorption of groups
and Least significant difference (LSD)to test any
statistically significant differences between each
two subgroups when ANOVA showed a statistical
significant difference within the same group.
Significance for all statistical tests was
predetermined at P≤ .05.
RESULTS
The staining effect of chlorhexidine 0.2%Effect of time:
Generally, for most groups the amount of light
absorption increase as time of immersion in the
chlorhexidine increase. But, in un bonded ceramic
brackets group the readings of light absorption in
control and after 1, 2 and 3 immersion hours in
the chlorhexidine 0.2% was not changed, the peak
reading in the immersion 3hours reading.
Ceramic bracket group (Table 1 and Fig. 1)
The Un bonded Ceramic bracket group showed a
statistical non-significant difference among
reading of control, 1, 2 and 3 immersion hours in
Chlorhexidine 0.2% by ANOVA test .
The ceramic bracket bonded with chemically
cured orthodontic adhesive group (No mix) and
The ceramic bracket bonded with light cured
orthodontic adhesive group showed statistical
significant difference among readings of
control,1, 2 and 3 immersion hours in
chlorhexidine 0.2% by ANOVA test. LSD test for
the ceramic bracket bonded with chemically cured
orthodontic adhesive group (No mix) revealed a
statistical significant difference when comparing
the control vs. 1 hours; a high significant
difference when comparing the control vs. 2 hours
and control vs. 3 hours; non significant difference
when comparing 1 hour vs. 2hours; while a high
significant difference when comparing 1 hour vs.
3 hours and 2 hours vs. 3 hours .
LSD test for the ceramic bracket bonded with
light cured orthodontic adhesive group revealed a
non significant difference when comparing
control vs. 1hours; a significant difference when
comparing control vs. 2hours, and control vs.
3hours, a highly significant difference in LSD test
when comparing 1 hour vs. 2 hours, 1 hour vs. 3
hours and 2 hours vs. 3 hours.
Composite bracket group (Table 1, Fig. 1)
One way ANOVA test showed a statistical
significant difference among reading of control, 1,
2 and 3 immersion hours in chlorhexidine 0.2%
for the Un bonded composite bracket group, the
The staining effect
composite bracket bonded with chemically cured
orthodontic adhesive (No mix) group and the
composite bracket bonded with light cured
orthodontic adhesive group
LSD test for the Un bonded composite bracket
group revealed a statistical significant difference
between the control and 1 immersion hours,
control and 2 immersion hours, control vs. 3
immersion hours and when comparing 1 hour vs.
2hours and comparing 1 hour vs. 3 hours; while a
non significant difference when comparing 2
hours vs. 3 hours.
LSD test for the composite bracket bonded with
chemically cured orthodontic adhesive (No mix)
group revealed a statistical significant difference
for all pair comparisons. LSD test for the
composite bracket bonded with light cured
orthodontic adhesive group revealed a statistical
significant difference between the control and 1
immersion hours, control and 2 immersion hours,
control vs. 3 immersion hours, and when
comparing 1 hour vs. 2hours and comparing 1
hour vs. 3 hours; while a non significant
difference when comparing 2 hours vs. 3 hours.
The staining effect of chlorhexidine 0.2%Effect of adhesives:
For both the ceramic and composite bracket
groups; the peak light absorption appear in
brackets bonded with no mix then the readings
decreased in brackets bonded with light cure and
the least reading of light absorption was in Un
bonded brackets for the same time interval in
control, 1, 2 and 3 hours of immersion in the
chlorhexidine 0.2% .
When comparing the amount of light absorption
by ceramic and composite brackets bonded with
different adhesives at the same time interval by
ANOVA test a statistical significant difference
was found (p<0.001) among brackets bonded with
no mix, brackets bonded with light cure and Un
bonded brackets. LSD test appeared that a
significant difference found when comparing Un
bonded brackets vs. brackets bonded with no mix,
un bonded brackets vs. brackets bonded with light
cure and when comparing brackets bonded with
no mix vs. brackets bonded with light cure.
DISCUSSION
The Un bonded Ceramic brackets was made from
Aluminum oxide which is an inert material due to
the crystalline structure of ceramic; as a result, it
cannot chemically interact to any of the
chlorhexidine molecules; also the glazed surface
of the bracket reduce the overall surface
roughness and the adsorption of chlorhexidine on
bracket surface. (Table 1, Fig. 1)
Vol. 24(2), 2012
chemically cured orthodontic adhesive (No mix)
when bonded to ceramic brackets might affect the
staining resistance of ceramic brackets or the
significant difference might due to staining of
orthodontic adhesive alone .
One of factors that affects light absorption values
is the time so that when time of immersion
increased; the adsorption of water molecules
(physisorption) increased, water is a softener of
plastics and increases the deterioration of the resin
matrix, and therefore water-soluble chlorhexidine
0.2% could penetrate the composite causing
chemical degeneration of the filler–resin bond and
solubility of the resin matrix, chlorhexidine also
contain 15% of alcohol; which increase the
monomer release from composite and increase the
surface degradation of adhesive; produce rough
surface which increase the chlorhexidine
deposition but this degradation effect might
require time so the non significant difference was
found in LSD test when comparing 1 hour vs. 2
hours in ceramic + no mix group (Figure 1)
when ceramic brackets bonded with light cured
orthodontic adhesive; the bonded adhesive might
affect the staining resistance of ceramic brackets
which explain the statistical significant difference
among reading of control, 1, 2 and 3 immersion
hours in ANOVA test(Figure 1); or the significant
difference might due to the ‘‘incomplete
polymerization’’ phenomenon of light cure
adhesive which occur due to number of factors
that affect the depth of photo activated cures,
including factors of illumination from the edges of
bracket and critical total transmittance value of
bracket in which duration and intensity of light
exposure may be attenuated by the bracket
structure, incomplete polymerization increase
monomer leaching and cause alteration in light
absorption values indicating a decreased color
stability of light cure composite.
Chlorhexidine infusion to Un bonded composite
bracket during immersion caused degradation of
composite bracket, swelling of composite, fissures
and cracks formation, a drastic reduction of the
polymer's molecular weight and lead to
discoloration. The degradation might be
somewhat retarded because the saturation of
composite bracket by chlorhexidine. So a non
significant difference when comparing 2 hours vs.
3 hours in LSD tests. (Figure 1)
The presence of no mix in composite bracket
bonded with chemically cured orthodontic
adhesive might provide additive effect by
increasing the bulk of material that interact with
chlorhexidine (bracket composite and adhesive
composite); Also the intensity of light passes
through the bulk of the resin material decreases
The staining effect
greatly, thus a statistical significant difference
among readings of control, 1, 2 and 3 immersion
hours showed in ANOVA test, and the significant
difference for all pair comparisons in LSD test(
Figure-1).
The light cured orthodontic adhesive bonded with
composite bracket present a non homogenous
profile due to oxygen inhibition at the surface
during
polymerization.
Oxygen
causes
deactivation of the free radicals and reacts with
the photo initiator, which decreases curing
efficiency of the oxygen-rich surface layers of the
material, the oxygen-rich surface layers could
hydroxylated by water absorption form negative
ionic layer that interact with positive cationic
group of chlorhexidine which increases the
deterioration of the resin matrix causing increase
in light absorption reading so a statistical
difference among readings of control, 1, 2 and 3
immersion hours in ANOVA test and a statistical
significant
difference
between
all
pair
comparisons except when comparing 2 hours vs. 3
hours in which a non significant difference
revealed in LSD test, that because the degradation
might be somewhat retarded due to the saturation
of composite and the adhesive resin by
chlorhexidine and the reaction reached an
electrostatic balance.
From this study we can conclude that:
1. Un bonded Ceramic brackets were not affected
by staining of chlorhexidine mouth wash
0.2%.
2. Ceramic and composite brackets bonded with
no mix orthodontic adhesive affected by
staining of chlorhexidine 0.2% slightly during
the first time of exposed to chlorhexidine then
the staining increase significantly with time.
3. Ceramic brackets bonded with light cured
orthodontic adhesive affected by staining of
chlorhexidine 0.2% less than ceramic brackets
bonded with no mix orthodontic adhesive.
4. Un bonded composite brackets and Composite
brackets bonded with light cured orthodontic
adhesive affected by staining of chlorhexidine
0.2% and this effect become limited with time.
5. Chemically cured orthodontic adhesive were
affected by staining effect of chlorhexidine
0.2% more than light cure orthodontic
adhesive; when it was bonded to ceramic or
composite brackets .
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the corner! The orthodontic materials insider 2005;
17(3).
Table 1: Descriptive statistics of the amount of light absorption by different bracket groups at
different time interval of immersion in chlorhexidine 0.2%
Brackets
Ceramic
Composite
Time
N
control
1 HR
2 HR
3 HR
control
1 HR
2 HR
3 HR
12
12
12
12
12
12
12
12
Un bonded Brackets
Mean
SD
SE
2.072 0.007 0.002
2.072 0.007 0.002
2.072 0.007 0.002
2.073 0.007 0.002
2.042 0.002 0.000
2.131 0.005 0.001
2.254 0.005 0.001
2.256 0.008 0.002
Bracket +no mix
Mean
SD
SE
2.315 0.005 0.001
2.325 0.010 0.003
2.332 0.020 0.005
2.350 0.005 0.001
2.261 0.004 0.010
2.355 0.011 0.003
2.428 0.006 0.001
2.447 0.005 0.001
Bracket +Light cure
Mean
SD
SE
2.224 0.008 0.002
2.232 0.005 0.001
2.252 0.020 0.005
2.274 0.010 0.003
2.245 0.014 0.004
2.280 0.005 0.001
2.347 0.008 0.002
2.348 0.004 0.001
Figure 1: the amount of light absorption of ceramic and composite bracket
groups at different time interval of immersion in chlorhexidine 0.2%
Vol. 24(2), 2012
Tooth attrition patterns
Tooth attrition patterns in a group of Iraqi adults sample
with different classes of malocclusion
(A comparative study)
Issam M. Abdullah, B.D.S. (1)
Ausama A. Al- Mulla, B.D.S., Dr.D.Sc. (2)
ABSTRACT
Background: Tooth attrition is wearing away of tooth structure during mastication. This study investigated tooth wear
patterns in adults with different classes of malocclusion and compared them with normal occlusion.
Materials and methods: The sample consisted of 363 subjects that were divided into 5 groups with an age range “1825” years: 85 normal occlusion, 128 class I with crowding, 90 class II division 1, 30 class II division 2 and 30 class III.
Dental wear was assessed by using a modified version of the tooth wear index.
Results:
1. The class I malocclusion group had statistically greater tooth wear in incisal surfaces of maxillary central and lateral
incisors, and mandibular lateral incisors than did the normal occlusion.
2. The class II division 1 group had statistically greater tooth wear in the occlusal surfaces of maxillary second
premolars, mandibular first and second premolars. Buccal surfaces of mandibular canines, mandibular second
premolars and mandibular first molars than did the normal occlusion.
3. The class II division 2 malocclusion group had statistically greater tooth wear in labial surfaces of mandibular
central and lateral incisors. Buccal surfaces of mandibular second premolars, mandibular first molars. Occlusal
surfaces of maxillary first and second premolars and mandibular second premolars than did normal occlusion.
4. The class III malocclusion group had statistically greater tooth wear in the occlusal surfaces of maxillary first and
second premolars than did normal occlusion.
Conclusion: In conclusion subjects with normal occlusion and those with different classes of malocclusions have
different tooth wear patterns.
Keywords: attrition, wear patterns, modified tooth wear index. (J Bagh Coll Dentistry 2012;24(2):114-119).
INTRODUCTION
Due to the decreasing occurrence of dental
caries in many societies, increasing attention has
focused on tooth wear from erosion, abrasion and
attrition (1). Tooth wear is a normal physiologic
process that occurs through a variety of
mechanisms and increases with age. It can be
defined as the noncarious loss of tooth substance
as a result of the combined processes of erosion,
attrition, and abrasion; these terms reflect specific
etiologic factors (2). Gradual attrition of the
occlusal surfaces of the teeth appears to be a
general physiologic phenomenon in all mammals,
in every civilization, and at all ages. Tooth wear
has characteristic features that must be
distinguished from abrasion and erosion and
characterized as flat, sharply or round angled and
polished surfaces and may come from excessive
attrition of one tooth against the other (3) .Smith
and Knight (4) introduced the tooth wear index
(TWI), which attempted to provide a solution to
some problems associated with measuring wear at
the individual and community levels. The TWI
and modified versions of it have been used in
many studies; this suggests widespread
acceptance (5-7). However, it was described as
flawed when used in an aging population, because
(1) MSc. Student, Department of Orthodontics, College of
Dentistry, Baghdad University.
(2) Professor, Department of Orthodontics, College of Dentistry,
Baghdad University.
it does not take into account teeth that were
restored due to wear (8). The modifications
matched the World Health Organization
standards, thus allowing application of the index
in broad epidemiologic surveys for both of
deciduous and permanent dentitions (9). Some
studies indicate that masticatory forces and
malocclusion are primary etiologic factors for
noncarious lesion development (10-14), although
other authors did not find this correlation (15-18).
Because of the high prevalence of malocclusions
as well as the controversies in the studies of tooth
wear, it is relevant to verify the pattern of tooth
wear of various occlusal relationships to help
professionals to differentiate between physiologic
and pathologic processes.
The sample has been selected randomly from
the students of Babylon university (college of
medicine, college of dentistry and college of
nursing) and some patients were selected
randomly from the patients attended the
orthodontic department and oral medicine
department of dentistry college of Babylon
University. Out of 440 persons only 363 subjects
were selected (18-25 years old) and divided into
five groups:
1. Group one included 85 subjects with normal
occlusion (45 males and 40 females).
Vol. 24(2), 2012
2. Group two included 128 subjects with class
I malocclusion with crowding (63 males and
65 females).
3. Group three included 90 subjects with class
II division 1 malocclusion (35 males and 55
females).
4. Group four included 30 subjects with class
II division 2 malocclusion (12 males and 18
females).
5. Croup five included 30 subjects with class
III malocclusion (14 males and 16 females).
The sample was taken in terms of the following
criteria:1. The sample was all of Iraqi Arab in origin.
2. No previous orthodontic treatment.
3. No extracted teeth up to the first molar.
4. No openbite.
5. No parafunctional habits.
6. No temporomandibular joint problems.
The surfaces of all teeth in the mouth were
scored according to tooth wear index by Smith
and Knight (4) modified by Sales Peres et al.(7).
The modifications matched the World Health
Organization standards (9), thus allowing
application of the index in broad epidemiologic
surveys for both of deciduous and permanent
dentitions. The modifications made calibration
easier because the modified tooth wear index does
not differentiate the depth of dentin involvement,
as does the original tooth wear index.
In addition, the modified version includes a
code for teeth that have been restored due to wear
(code 4) and another code for teeth that cannot be
assessed (code 9); the amount of permanent tooth
wear is scored by numbers (Table 1). Each 2 groups
were compared using Mann Whitney test for the
frequency and severity of wear on each surface of
each group of teeth.
RESULTS
In total, 17424 dental surfaces were evaluated. Of
these, 64.2 % had no dental wear (score 0), 33.8%
had incipient lesions (score 1), 1.3 % had
moderate lesions (score 2) and 0.7% were
excluded (score 9).No severe lesions were found.
1. Class I (crowding):
The class I malocclusion group had statistically
greater tooth wear in incisal surfaces of maxillary
central incisors, incisal surfaces of maxillary
lateral Incisors and incisal surfaces of mandibular
lateral incisors ( table 2) than did the normal
occlusion.
The normal occlusion group had statistically
greater tooth wear in the incisal surfaces of
maxillary canines and Buccal surfaces of
mandibular first (tables 2), than did the class I
malocclusion (crowding).
2. Class II division 1:
greater tooth wear in the incisal surface of
maxillary lateral incisors incisal surface of
mandibular central incisors and incisal surface of
maxillary canine than did the class II division 1
malocclusion group, (table 3). The class II
division 1 group had statically greater tooth wear
in the occlusal surfaces of maxillary second
premolars, occlusal surfaces of mandibular first
premolars , occlusal surfaces of mandibular
second premolars (table 3), labial surfaces of
mandibular canines, buccal surfaces of
mandibular second premolars and buccal surfaces
of mandibular first molars than did the normal
occlusion group, (table 3)
3. Class II division 2:
maxillary lateral
and incisal surfaces of
maxillary canines than did class II division 2
group, (table 4). The class II division 2
malocclusion group had statically greater tooth
wear in labial surfaces of mandibular central
incisors, labial surfaces of mandibular lateral
incisors, buccal surfaces of mandibular second
premolars, buccal surfaces of mandibular first
molars, occlusal surfaces of maxillary first
premolars, occlusal surface of maxillary second
premolars, and occlusal surfaces of mandibular
second premolars than did normal occlusion
group, (table 4).
4. Class III:
maxillary central incisors, incisal surface of
maxillary lateral incisors, incisal surface of
maxillary canines, incisal surfaces of mandibular
central incisors, incisal surfaces of mandibular
lateral incisors, incisal surfaces of mandibular
canines, palatal surfaces of maxillary central
incisors, palatal surface of maxillary lateral
incisor, palatal surface of maxillary canines,
occlusal surfaces of mandibular first molars and
buccal surfaces of mandibular first molars than
did class III group, (tables 5). The class III
malocclusion group had statistically greater tooth
wear in the occlusal surfaces of maxillary first
premolars and surfaces of maxillary second
premolars than did normal occlusion group, table
(table 5).
DISCUSSION
The results of this study showed that the
normal occlusion patients and those with class I
malocclusion (crowding), class II division 1, class
II division 2 and class III had some tooth wear.
Vol. 24(2), 2012
However, the groups had different tooth wear
patterns, Tables (2-5).
1. Class I malocclusion (crowding)
The normal occlusion group differs from class I
with crowding in that the normal occlusion tooth
wear was greater on the incisal surfaces of the
maxillary
canines,
compared
with
the
corresponding surfaces of the malocclusion
group(table 2), this probably occurred because of
the
normal
anteroposterior
relationship,
establishing immediate lateral guidance during
lateral mandibular excursions (19). Since these
teeth disclude the posterior teeth during lateral
mandibular functional movements, it seems
logical that they have greater wear, this finding
came to be in agreement with Janson et al.2010
(23)
and Oltramari et al. 2010 (24). As a result of
unfavorable positioning of the canines in class I
crowding as in many cases of class I coming with
buccally malposed canines these teeth also do not
disclude the posterior teeth as frequently as in
normal occlusion, because of interferences of the
posterior teeth (19, 25). Thus, there is less wear on
the incisal surfaces of the maxillary canines in the
class I group.
Thus, there is less wear on the incisal surfaces of
the maxillary canines in the class I group. The
buccal surfaces of mandibular first molars had
tooth wear more than the class I malocclusion
(crowding), this may be due to the subjects with
crowding had narrower arches than the normal
occlusion (20, 21) so the maxillary first molars did
not probably overlap the mandibular molars.
Thus, there is less wear in the buccal surface of
mandibular first molar because all of the wear
located in areas of occlusal contact (22). The more
tooth wear in incisal surfaces of maxillary and
mandibular incisors in class I crowding subjects
may be due to irregularities and disarrangement of
these teeth, table.
2. Class II division 1 malocclusion
In the normal occlusion group, tooth wear was
greater on the incisal surfaces of the maxillary
lateral incisors and canines and mandibular
central incisors compared with the II division 1
malocclusion (table 3). Greater tooth wear in the
anterior region in the normal occlusion group
probably occurred because of normal vertical and
horizontal
anterior
tooth
relationships,
establishing immediate anterior and lateral
guidance during protrusion and lateral mandibular
excursions, respectively (19, 25). As we mentioned
above these teeth disclude the posterior teeth
during mandibular functional movements, so it
will have greater wear, this finding came to be in
agreement Janson et al. (23) and partial agreement
with Oltramari et al. (24) and this may be due to
size and age of sample.
Class II Division 1 malocclusion group showed
greater tooth wear on the posterior teeth (table 3),
this may be due to two factors. One is the large
overjet that increases the likelihood of
interferences of the posterior teeth during
protrusion until the incisors make contact as the
mandible is advanced (19, 25). The other is that,
because the canines are not in a favorable position
to disclude the posterior teeth, these take the role
of the canines during lateral mandibular
excursions and are therefore subjected to greater
wear.
3. Class II division 2 malocclusion
greater on the incisal surfaces of the maxillary
lateral incisors and the maxillary canines,
compared with the corresponding surfaces of class
II division 2 malocclusion group (table 4). Less
wear on the incisal surfaces of the maxillary
lateral incisors in the Class II malocclusion group
presumably is a consequence of the labial
positioning of these teeth in this type of
malocclusion, which also is characterized by
uprighted central incisors, deep overbite, and
normal overjet (26-29) .With this interocclusal
arrangement, disclusion on protrusion is carried
out primarily by the maxillary central incisors
with occasional contact of the lateral incisors.
Greater tooth wear on the incisal surfaces of the
canines in the normal occlusion group, probably
occurred because of the normal anteroposterior
relationship, establishing immediate lateral
guidance during lateral mandibular excursions (19,
25)
. In comparison with normal occlusion, subjects
with class II division 2 had greater wear on the
labial surfaces of mandibular incisors and this
may be due to this type of malocclusion
characterized by uprighted central incisors, deep
overbite, and normal overjet (26-29) , thus during
protrusion subjected to greater tooth wear.
Subjects with Class II Division 2 malocclusion
had greater wear on the posterior teeth (occlusal
surface of maxillary first and second premolars
and mandibular second premolar and buccal
surfaces of maxillary second premolar and first
molar), a difference that was statistically
significant compared with that of the normal
occlusion sample, and this may be because the
canines are not in a favorable position to
disocclude the posterior teeth during lateral
excursions in class II division 2 malocclusion, the
posterior teeth assume this role and consequently
have greater wear than observed in the normal
occlusion group. This occlusal configuration
occurs because of the broad, square-shaped
Vol. 24(2), 2012
maxillary arch with a relatively normal
mandibular arch, characteristics of this
malocclusion (26-29). These surfaces are worn
during lateral movements of the mandible on the
working side.
4. Class III malocclusion
greater on the incisal surfaces of the anterior teeth
(maxillary and mandibular), compared with the III
malocclusion (table 5). Greater tooth wear in the
anterior region in the normal occlusion group
probably occurred because of normal vertical and
horizontal
anterior
tooth
relationships,
establishing immediate anterior and lateral
guidance during protrusion and lateral mandibular
excursions, respectively (19, 25), in contrast to
subjects with class III malocclusion have lesser
tooth wear in anterior teeth and this may be due to
many subjects with class III come with edge to
edge or sometimes openbite and the overjet and
overbite decrease (30-32) ,this seems to be the
reasons for less wear in anterior teeth of class III
subjects. Due to the reverse relationship in class
III malocclusion, the normal occlusion group has
greater wear in palatal surfaces of maxillary
anterior teeth. On the other hand, subjects with
normal occlusion have greater wear in buccal
surfaces of mandibular first molars, and the
subjects with class III malocclusion have less
wear in molars which may be due to the fact that
the maxillary arch widths were usually narrower
than the mandibular arch widths and lingually
positioned maxillary posterior teeth (posterior
crossbite) are often seen in the class III
malocclusion (33-34), it seems logical that they have
less wear in molars. Subjects with class III have
fewer teeth wear than the normal occlusion group.
On the other hand, patients with Class III
malocclusion had greater wear on the maxillary
premolars, a difference that was statistically
significant compared with that of the normal
occlusion sample, and this may be because the
canines are not in a favorable position to disclude
the posterior teeth during lateral excursions in
class III malocclusion, the premolars assume this
role and consequently have greater wear than
observed in the normal occlusion group.
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Table 1: Criteria used for the measurement of tooth wear, according to the modified tooth wear
index
Permanent
teeth
Criteria
scores
Normal _ no evidence of wear
0
1
2
3
4
9
Description
No loss of surface features
Loss of enamel giving a smooth glazed shiny appearance,
Incipient _ tooth wear into enamel
dentine is not involved
Extensive loss of enamel with dentine involvement.
Moderate tooth wear into dentine
Exposure of dentine
Severe _ tooth wear into pulp or Extensive loss of enamel and dentine with secondary dentine
secondary dentin.
or pulp exposure
Restored _tooth wear leading to
The tooth received restorative treatment due to tooth wear
restoration
Extensive caries, large restoration, fractured tooth and
Could not be assessed
missing tooth,
Table 2: Intergroup tooth wear comparisons, normal occlusion and class I malocclusion
(Mann-Whitney test)
tooth
Class I malocclusion
(crowding)
Mean of scores SD Mean of scores SD
Normal occlusion
Incisal/ occlusal surface
Maxillary teeth
0.729
0.521
0.867
Centrals
0.552
0.5
0.781
Laterals
0.776
0.542
0.539
Canines
Mandibular teeth
0.765
0.427
0.898
Lateral /right
Labial surfaces
Mandibular teeth
0.2
0.402
0
First molars
*Statistically significant at P < 0.05
P
0.341 0.01*
0.415 0.00*
0.613 0.002*
0.303 0.01*
0
0.001*
Vol. 24(2), 2012
Table 3: Intergroup tooth wear comparisons, normal occlusion and class II division 1(MannWhitney test)
tooth
Normal occlusion
Class II division 1
Maxillary teeth
0.529
0.526
0.366
Laterals
0.776
0.542
0.533
Canines
0.176
0.383
0.288
Second premolars
Mandibular teeth
0.859
0.515
0.7
Centrals
0.294
0.458
0.5
First premolars
0.129
0.337
0.411
Second premolars
Palatal surfaces
Maxillary teeth
0.471
0.547
0.444
Centrals
Labial/ buccal surfaces
Mandibular Teeth
0.071
0.258
0.167
Canines
0.047
0.213
0.177
Second premolars
0.2
0.402
0.489
First molars
P
0.484 0.04*
0.622 0.003*
0.456 0.01*
0.507 0.04*
0.503 0.006*
0.495 0.001*
0.499 0.86
0.375 0.049*
0.384 0.007*
0.489 0.001*
Table 4: Intergroup tooth wear comparisons, normal occlusion and class II division 2 (MannWhitney test)
tooth
Normal
Class II division 2
occlusion
Maxillary teeth
0.529
0.526
0.233
Laterals
0.776
0.542
0.2
Canines
0.388
0.537
0.633
First premolars
0.176
0.413
0.5
Second premolars
Mandibular teeth
0.129
0.337
0.3
Second premolars
Labial surfaces
Mandibular teeth
0.059
0.237
0.2
Centrals
0.024
0.152
0.2
Laterals
0.047
0.213
0.166
Second premolars
0.188
0.393
0.5
First molars
P
0.43 0.007*
0.407 0.005*
0.615 0.045*
0.731 0.013*
0.479 0.035*
0.407 0.024*
0.406 0.001*
0.379 0.037*
0.508 0.001*
Vol. 24(2), 2012
Clinical significance of sella
Clinical significance of sella turcica morphologies and
dimensions in relation to different skeletal patterns and
skeletal maturity assessment
Kasim A. Obayis, B.D.S. (1)
Ali I. Al-Bustani, B.D.S., M.Sc. (2)
ABSTRACT
Background: Sella turcica is a saddle-like structure based on the roof of the sphenoid bone and has an important
role in orthodontic diagnosis and treatment planning. The aims of the study were to assess sella shape and size in an
adolescent Iraqi sample in different skeletal classes and to verify the possibility of clinical application of sella turcica
in skeletal maturity estimation.
Materials and Methods: The study sample composed of (140) Iraqi adolescent subjects aged 10-16 years (91 females,
49 males); every subject had true lateral cephalometric radiograph. The sample was subjected to 2 classifications:
the 1st included three skeletal classes according to ANB angle, and the 2nd included accelerative and decelerative
groups according to maturity indicators of cervical vertebrae seen radiographically. In each classification, sella size
was measured using three linear measurements (S.length, S.depth, and S. diameter).
Results: Most of sella turcica measurements were not different statistically among the skeletal classes, and that
specific sella turcica linear measurements can not be obtained for each specific skeletal class throughout the
pubertal period. Normal sella was the predominant over the other morphological aberrations in both classification
systems, while these morphologies occurred more frequently in class II and III. Sella depth and diameter were
significantly higher in the decelerative than accelerative group, while non significant difference was found
concerning sella shapes between the two groups.
Conclusions: It was concluded that Sella depth and sella diameter measurements can be utilized clinically for
pubertal growth phase determination, while sella morphology can not be diagnostic for the accelerative and
decelerative pubertal growth phases.
Keywords: Sella Turcica, Pubertal growth, Skeletal Maturity. (J Bagh Coll Dentistry 2012;24(2):120-126).
INTRODUCTION
Several landmarks within the cranium have been
determined to act as reference points when tracing
cephalometric radiographs. These landmarks are
used to measure positions of structures (such as
the maxilla or mandible) in relation to the
cranium, or to themselves. The benefits gained
from studying these structures serve: in assisting
the orthodontist during diagnosis, as a tool to
study growth, and in evaluation of orthodontic
treatment results.(1)
One of the most commonly used cranial
landmarks for cephalometric tracing is sella point.
This point is located in the centre of the sella
turcica, with the turcica housing and protecting
the pituitary gland in the cranial base.(2)
Any abnormality or pathology in the gland could
manifest from an altered shape of the sella turcica
and/or a disturbance in the regulation of secretion
of glandular hormones. (3-6) The anatomy of the
sella turcica has been described as being
variable.(7) Morphologically, three basic types—
oval, round, and flat—have been classified, the
oval and round types being the most common.
During embryological development, the sella
turcica area is a key point for the migration of the
neural crest cells to the frontonasal and maxillary
developmental fields.(8)
(1) M.Sc. Student, Department of Orthodontics, Dental College,
(2) Assistant professor, Department of Orthodontics, Dental
College, University of Baghdad.
For this reason, it is very important to study the
effect of puberty (a period of significant body
changes) on the normal morphology of this
landmark clearly in a young sample, as it is
studied in an adult sample, since this has a great
importance in orthodontic diagnosis and treatment
planning.
Previously, when studying the sella turcica size
(length, depth and diameter) and its relation to
different skeletal patterns, no statistically
significant correlation between facial type and the
mean sella turcica area of the pituitary fossa had
been presented.(9) However, Alkofide (1) when
evaluated skeletal type and linear dimensions of
sella turcica, a significant difference was found.
When comparing skeletal class II and class III
subjects, a significant difference was observed
between the diameter of the sella turcica in both
skeletal classes which may be attributed to
genetic factors.
Although the morphology and dimensions of
sella turcica have been studied by previous
researchers on adult Iraqi samples (10,11), until now
no Iraqi study has been done to evaluate the linear
dimensions and morphological structure of sella
turcica in an adolescent Iraqi sample. Although
no significant differences had been obtained
between males and females in terms of mean
linear dimensions of the sella turcica, previous
studies (1,12,13) found a significant effect of age on
Orthodontics, Pedodontics, and Preventive Dentistry 120
Vol. 24(2), 2012
sella turcica dimensions. So the present study was
the first Iraqi study that evaluated the linear
dimensions and morphological structure of sella
turcica in an adolescent Iraqi sample, and their
relationship to different skeletal patterns.
Furthermore, this study was (for the 1st time)
attempted to test the possibility of clinical
employment of Sella Turcica in pubertal growth
estimation.
The sample
The sample of this study consisted of radiographs
for patients who were attending the preventive
and orthodontic clinics at the teaching hospital of
the College of Dentistry – Baghdad University
seeking paedodontic and orthodontic treatments.
The sample was all of Iraqi origin, with an age
ranging between 10-16 years. Out of 185 subjects
examined, only 140 subjects (49 males and 91
females) met the inclusion criteria including no
history of systemic disease (clinically healthy
patient) or trauma in the craniofacial complex, no
syndromes (clefts of the lips and palate), and no
history of previous orthodontic treatment. Every
subject has to be free from any congenital or
acquired malformations of the cervical vertebrae
(seen radiographically).(14)
The sample has been subjected to two
classification systems. 1st, according to ANB
angle (15-17) into skeletal class I (13 males, 38
females), class II (20 males, 20 females), and
class III (16 males, 33 females). 2nd, according to
Maturity Indicators of Cervical Vertebrae (CVMI)
(14)
into accelerative (56) and decelerative (43)
groups respectively.
In the 2nd classification system, by excluding the
easily recognized skeletal (I and VI) stages at the
extremes of pubertal growth stages from the total
radiographs, the total sample (140) became (99)
radiograph.
METHOD
Cephalometric Analyses
All Lateral Cephalometric Images were analyzed
by an AutoCAD program (version 2007) to
measure the ANB angle and to calculate the linear
measurements of Sella Turcica.
Size of Sella Turcica
According to Silverman (18) and Kisling (19) the
following lines were measured to determine the
size of the Sella Turcica, all the reference lines
used were situated in the midsagittal plane (figure
1):
A) The length of the Sella Turcica: Was
measured as the distance from the Tuberculum
Sellae (TS) to the tip of Dorsum Sellae (DS).
B) The depth of Sella Turcica: Was measured as
a perpendicular from the line mentioned above to
the deepest point on the floor of the fossa (BPF).
C) The anteroposterior greatest diameter of the
Sella Turcica: Was measured from the
Tuberculum Sellae (TS) to the furthest point on
the posterior inner wall of the fossa (SP).
Shape of Sella Turcica
For the assessment of the morphological
aberrations of the sella turcica (after enlargement
of its view), in addition to the normal morphology
of sella turcica traced in (figure 2); the different
morphological appearances of the sella turcica
described by Axelsson et al. (13,20) (figure 2), were
used to classify sella shapes in the current study.
The six morphological variations that are rated as
normal included oblique anterior wall, sella
turcica bridging, double contour of the floor,
irregularity (notching) in the posterior part of the
dorsum sellae, extremely low sella turcica, and
pyramidal shape of the dorsum sellae.
Skeletal Maturation Assessment
The second part of the study has concerned with
verifying the possibility of using the sella turcica
for pubertal growth estimation by depending on a
method of skeletal maturation assessment using
the Maturity Indicators of Cervical Vertebrae.
This method has been developed by Hassel and
Farman (14) (CVMI). They described certain
criteria for assessing maturational changes on the
second, third, and fourth cervical vertebrae, which
can be visualized on the lateral cephalograms
even if a thyroid protective collar has been worn
during radiation exposure.
The two skeletal stages (stages I and VI)
represent the extremes of the pubertal growth
period, which can be very easily diagnosed
clinically by the orthodontist. Greater efforts
were, therefore, done to concentrate on subjects at
the skeletal stages which require certain maturity
indicators for their determination, specially
skeletal stages III and IV. For more facility and
practicality, the six pubertal growth stages have
been condensed only into two growth phases or
stages (accelerative and decelerative),i.e., by
excluding the two skeletal stages (stages I and VI)
at the extremes of the pubertal growth period, the
two accelerative (stages II and III) and the two
decelerative (stages IV and V) were combined to
represent the accelerative and decelerative groups,
respectively. (14,21,22)
Furthermore, since males and females pass
during puberty through the same physiological
sequence,i.e., both progress towards skeletal
Vol. 24(2), 2012
maturity with advancement of age and growth;
therefore, the total sample has been classified into
accelerative and decelerative groups without male
and female classification.
Statistical Analysis
The statistical analysis included:
I. Descriptive Statistics: Including (Mean value,
Standard deviation, Number and Percentage, and
Statistical tables).
II. Inferential Statistics: Including (ANOVA test,
LSD test, Independent t-test, and Likelihood Ratio
test (Lx2))
RESULTS AND DISCUSSION
The literature involves different age ranges, with
the puberty may begin as early as 9 or 10 years,
and may end as late as 18 or 19 years of age. By
selecting the 10-16 years age range, therefore,
reconcilement of the different findings about the
pubertal timing has been done. (22,23) Size
measurements of the sella turcica have, to-date,
almost solely been used as a diagnostic tool
concerning expanding tumors or tumor-like
processes in the pituitary gland. (1,24,25)
Statistically, there were non significant gender
differences in all sella turcica linear
measurements (S. length, S. depth and S.
diameter) in skeletal class II and III, while the two
measurements (S. depth and S. diameter) were
significantly higher in females than in males
dealing with skeletal class I (table 1). This may be
explained by: 1st, The explicit discrepancy in
gender distribution in this skeletal pattern.2nd, The
earlier pubertal growth spurt in females which
may influence their sella measurements.
Genetic factors most likely play a leading role in
male-female growth differences. The marked
advancement of girls over boys in the rate of
maturation is attributed to the delaying action of
the Y chromosome in males. By delaying growth,
the Y chromosome allows males to grow over a
longer period of time than females, therefore
making possible greater overall growth. (26)
On the other hand, non significant gender mean
difference was found concerning the sella length
in class I. This may be attributed to a greater
pubertal growth influence on the vertical than on
the anteroposterior (Sella length) dimension. By
comparing the subjects’ linear dimensions of sella
turcica with normative data from the literature, the
former result was in agreement with Alkofide (1)
and Yassir et al.(10), while the latter result was in
agreement with Silverman (18), Chilton et al.(27),
and Elster et al.(28) who revealed that the pituitary
fossa of males tended to be larger than that of
females during childhood. After that, due to the
pubertal growth spurt in females which begins 2
years earlier than males, a significant change in
pituitary fossa size occurs in females from 11 to
14 years of age. Thereafter, the late growth
acceleration in males, which is usually about 2
years later than females, results in an approximate
equalization in sella area in both genders.
On the other hand, by comparing sella
measurements among the skeletal classes, it was
found that the sella depth was significantly higher
in class I than in class II (table 1). This finding
may be attributed to genetically determined
growth factors. According to this study result,
specific sella turcica linear measurements can not
be obtained for each specific skeletal class
throughout the pubertal period.
In comparison with adult studies MeyerMarcotty (6), Yassir et al. (10), and Al-Ani (11), it
could be demonstrated that the length, depth, and
diameter of the sella turcica region of all
examined patients in this study tended to be
smaller, a finding that confirms the effect of age
on sella measurements.
Investigations concerning the sella turcica have
not only focused on size, but also on morphology.
(1,2,6,10,11,13,20,29)
No previous studies concerning
sella morphology have mentioned the gender
difference in each skeletal class separately during
pubertal period alone, rather previous studies have
either compared between males and females as a
total sample (Yassir et al.(10) and Axelsson et
al.(13,20)) or they compared between the classes (as
a total in each class) without giving gender
difference (Meyer-Marcotty et al.(6); Yassir et
al.(10); Abdel-Kader (30)). Furthermore, these
studies used the frequency and percentage as a
baseline for comparison, i.e. descriptive statistics
only, and they did not use inferential statistical
analyses between genders and among the classes.
Normal sella turcica was the predominant shape
over the other morphological variations in all
skeletal classes (table 2). This predominance can
be attributed to growth and development basis.
Sella turcica is expected to become oval to more
round (i.e. normal) with craniofacial growth
progression. This is true if we follow the normal
growth and development of sella turcica, as it
appears as a shallow-like depression at the fetal
stage, while as the growth of the cranium
proceeds it becomes slightly oval to round at the
permanent dentition stage (at adolescence). This
result comes to be in agreement with (Alkofide (1);
Yassir et al.(10); Al-Ani (11) and Axelsson et
al.(13,20)) their results showed that a normal sella
turcica morphology was seen in two-thirds of the
subjects,
while
the
remainder
showed
dysmorphological appearances.
Vol. 24(2), 2012
Any deviation from the above mentioned sella
growth and development map can account for the
occurrence of these shapes. Statistically, only in
class III, Likelihood Ratio test showed significant
difference between males and females for the
different shapes of sella turcica. Skeletal class III
can be considered as a type of craniofacial
deviation in which growth pattern is abnormal.
Furthermore, greater percentages of males are
affected by this type of malocclusion than
females. So, if we consider morphological sellar
aberrations as a deviation from the normal
development of sella turcica, abnormal sella may
occur more frequently in this class and mostly in
males.
The predominance of non significant sella
morphology differences between genders enabled
dealing with the subjects as a total sample within
each
skeletal
class.
Although
multiple
comparisons were made among the classes, a
significant difference only was present between
class II and III (table 3). Genetically determined
growth factors may have a role. Formation and
development of the sella turcica and dental
structures share, in common, the involvement of
neural crest cells. In fact, the anterior part of the
sella turcica is believed to develop mainly from
neural crest cells, (31,32) so any structural
deviations in the anterior wall are believed to be
associated with specific deviations in the facial
skeleton.(33) Moreover, During embryological
development, the sella turcica area is a key point
for the migration of the neural crest cells to the
frontonasal and maxillary developmental fields. (8)
The majority of normal sella turcica appeared to
be present in skeletal class I followed by class III
and then by class II. This may be attributed to
structural adaptation phenomenon. The sella
turcica structural development is influenced by
growth and development of the surrounding
structures (i.e. anterior and posterior cranial bases,
brain, and nasomaxillary complex). Normal and
harmonious growth behavior of these structures
would result in a normal sella shape, while any
deviation from this harmonious growth might lead
to sella turcica morphological aberrations which
occurred mostly in class III.
Determining the pubertal growth phase
(accelerative or decelerative) is an important aim
clinically, irrespective of the specific stage of that
phase. Dealing with (table 4) there was non
significant difference of sella mean length
between the accelerative and decelerative groups.
Conversely, the other two measurements (S. depth
and S. diameter) were higher in the decelerative
than accelerative group. Statistically, there were
significant and highly significant differences in
the mean values of sella (depth and diameter)
between groups, respectively.
This finding may be related to growth and age
progression background. Bone apposition on the
anterior part of the interior surface of the sella
turcica is ceased at an early age, whereas
resorption is continued for a long time on the
distal part of the sella floor and on the posterior
wall.(35-38) Furthermore, the anterior wall of the
sella turcica reaches stability at 5-6 years of age
and the tuberculum sella and the posterior wall of
the sella turcica stop growing at ages of 18 years
in males and 16 years in females (at the ends of
pubertal growth).(39) This can give us two
important findings. First, the reference point 'sella'
would, therefore, with growth and age
progression, be displaced backwards and
downwards. Second, Sella depth and diameter
would be increased with age and at specific time
females are having higher sella measurements
than males.
Related previous studies,(1,2,9,12,13,18,27,29,40) have
dealt with the age factor, rather than pubertal
growth spurt. They mostly confirmed two
findings: 1st, sella size increases significantly with
age; 2nd, sella depth and diameter are the most
influenced linear measurements by the age factor
in comparison with sella length.
According to this study result, sella depth and
sella diameter measurements can be utilized
clinically
for
pubertal
growth
phase
determination. This requires larger sample
collection so that cut-off points and intervals
(ranges) can be estimated for the accelerative and
decelerative stages.
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Vol. 24(2), 2012
Table 1: Descriptive and Inferential Statistics for Sella measurements in (mms).
Sella length
Sella depth
Sella diameter
Sex n Mean SD P.value sex n Mean SD P.value sex n Mean SD P.value
♂ 13 6.26 0.8
♂ 13 9.11 1.57
♂ 13 6.94 1.8
.001**
.006**
♀ 38 10.3 1.2
cl. I
♀ 38 6.54 1.33 .39 (NS) ♀ 38 7.52 1.25
(HS)
(HS)
total 51 7.2 1.27
total 51 10 1.39
total 51 6.64 1.46
♂ 20 6.7 1.06
♂ 20 9.5 1.33
♂ 20 7.08 1.69
0.7
0.36
0.48
♀ 20 6.34 1.37
♀ 20 9.79 1.27
cl. II
♀ 20 6.88 1.5
(NS)
(NS)
(NS)
total 40 6.52 1.22
total 40 9.64 1.29
total 40 6.98 1.58
♂ 16 6.41 1.25
♂ 16 9.17 1.57
♂ 16 6.64 2.08
0.3
0.26
0.1
♀ 33 6.9 1.47
♀ 33 9.92 1.42
cl. III ♀ 33 7.17 1.45
(NS)
(NS)
(NS)
total 49 6.74 1.41
total 49 9.68 1.5
total 49 6.99 1.67
ANOVA
0.46 (NS)
ANOVA
0.041*
ANOVA
0.37 (NS)
sk. class
Class I- Class II
Class I- Class III
Class II- Class III
Mean difference P-value Mean difference P-value Mean difference P-value
0.68
0.015*
0.46
0.08 (NS)
-0.22
0.44 (NS)
Sella depth
Variable
Table 2: Number distribution and percentage of Sella shape in skeletal classes with gender
difference.
Class I (n=51)
Class II (n=40)
Class III (n=49)
Male
female
male
female
male
female
p-value
p-value
p-value
n
%
n
%
n % n %
n
%
n
%
13 65% 10 50%
7 43.75% 23 69.70%
Normal 7 53.80% 29 76.30%
0.194
0.429
0.035
3 15% 2 10%
3 18.75% 1 3%
Oblique 2 15.40% 1 2.60%
3 15% 4 20%
3 18.75% 1 3%
Bridge 3 23.10% 2 5.30%
0 0.00% 2 10%
0 0.00% 0 0.00%
Notching 0 0.00% 2 5.30%
0 0.00% 0 0.00%
0 0.00% 5 15.20%
Double 0 0.00% 1 2.60%
0 0.00% 1 5%
2 12.50% 2 6.10%
Pyramidal 1 7.70% 3 7.90%
1 5% 1 5%
1 6.25% 1 3%
0 0.00% 0 0.00%
Low
NS 20 100% 20 100% NS 16 100% 33 100%
S
Total 13 100% 38 100%
S. shape
significance
significance
significance
Table 3: Number distribution and percentage of Sella shape for total sample with shape
difference among skeletal classes.
Skeletal class
Shape
Sella shape Class I Class II Class III
C.S
difference
n % n
%
n
%
Normal 36 70% 23 57.50% 30 61.20%
Oblique 3 5.90% 5 12.50% 4 8.20% Cl. I- II P-value 0.205 NS
Bridge 5 9.80% 7 17.50% 4 8.20%
Notching 2 3.90% 2 5.00% 0 0.00%
Cl. I- III P-value 0.162 NS
Double 1 2.00% 0 0.00% 5 10.20%
Pyramidal 4 7.80% 1 2.50% 4 8.20%
0 0.00% 2 5.00% 2 4.00% Cl. II- III P-value 0.048* S
Low
51 100% 40 100% 49 100%
Total
Table 4: Descriptive statistics of S. Turcica linear measurements for Pubertal growth stages
with mean difference statistics.
Mean difference
(d.f.=97)
P-value t-value
0.682
0.41
(NS)
.020*
-2.365
(S)
.009**
-2.677
(HS)
Stage of growth
Decelerative(N=43) Accelerative(N=56) Variable
SD Mean Max. Min. SD Mean Max. Min.
Sella
1.4 6.81 9.86 4.29 1.53 6.93 11.46 4.39
length
Sella
1.37 7.32 9.78 3.8 1.34 6.67 9.66 3.43
depth
Sella
1.16 10.4 14.08 7.03 1.25 9.74 13.96 7.26
diameter
NS = P> 0.05 Non significant. * = 0.05 ≥ P > 0.01 Significant. ** = P ≤ 0.01 highly significant.
Vol. 24(2), 2012
SP
Figure 1: Normal sella turcica morphology and reference lines used for measuring sella size. TS,
tuberculum sella; DS, dorsum sella; BPF, base of the pituitary fossa; SP, sella posterior; white
line, length of sella; red line, diameter of sella; blue line, depth of sella.
Figure 2: Tracings and details from lateral cephalograms of the different morphological types
of sella turcica: (A) Double contour of the floor, (B) extremely low sella turcica, (C) Sella turcica
bridging, (D) Irregularity (notching) in the posterior part of the dorsum sellae (E) oblique
anterior wall and (F) Pyramidal shape of the dorsum sellae.
Vol. 24(2), 2012
Clinical performance comparison
Clinical performance comparison of a clear advantage
series II durable retainer with different retainers' types
Mustafa M. Al-Khatieeb, B.D.S., M.Sc. (1)
ABSTRACT
Background: The orthodontic retainers are either fixed or removable. Each has its own advantages and
disadvantages. The goal of the current study was to evaluate the new Clear Advantage Series II durable thermovacuum formed invisible orthodontic retainer material and compare the clinical performance of such retainer with
the most standard types of retainers (convention Clear Advantage Series I thermo-vacuum formed invisible retainer,
Hawley, and the fixed lingual bonded retainers). The conducted study is the first attempt to evaluate and compare
the clinical performance of different retainers' types.
Subjects and methods: Twenty finished fixed orthodontic patients starting the retention phase were divided into four
groups. Each group consisted of five patients (3 females and 2 males), mean age ranged 18-30 years old. Members
of the first group were given the new thermo-vacuum formed invisible Clear Advantage Series II durable retainer
material (CII), While the second, third, and fourth groups were given standard thermo-vacuum formed invisible Clear
Advantage Series I retainer material (CI), Hawley retainer (HR), and fixed lingual bonded retainers "cuspid to
cuspid"(FR), respectively. Ten variables were applied on the twenty patients to evaluate the clinical performance of
the four retainers' types, the ten variables were evaluated and judged by the operator with the patient as three nonparametric categorical descriptions: superior (+), acceptable (±), and inferior (-) properties.
Results: It was found that patients were compliant with all types of retainers initially, and the compliance decreased
at a much faster rate with both types of themo-vacuum formed retainers (CII and CI) than with HR and FR retainers,
and patient's compliance is greater with HR and FR retainers than with CII and CI retainers. A comparison of the total
variables of the clinical performance at total time intervals using chi-square showed that there was a significant
difference (P<0.05) in the acceptable categorical description between CII and CI retainers and very high significant
difference (P<0.001) between CII, HR, and FR retainers.
Conclusion: it was found that the new thermo-vacuum formed Clear Advantage Series II durable retainer showed a
combination of removable, comfortable, aesthetic, better speech, superior retention, relatively not producing bad
taste and odor, hygienic, least soft tissue irritability, superior construction and chair-side time, and durable, it will be
more favorable clinical performance appliance to both the patient and the orthodontist.
Keywords: Clinical performance, Clear Advantage Series II Durable, Retainers. (J Bagh Coll Dentistry 2012;24(2):127136).
INTRODUCTION
In orthodontics, although the patient may feel
that treatment is complete when the appliances are
removed, an important stage lies ahead, which is
the retention phase, retention has been defined by
Moyers (1) as the process of maintaining the
moved teeth into the new position long enough to
aid in stabilizing their correction. Relapse has
been defined as a return of teeth to their original
position or a shift in arch relationship after the
end of treatment, because teeth tend to move back
to their pre-treatment positions if they are not
retained (2-4). The etiology of relapse is
multifactorial and can be divided into three main
areas: physiological recovery, unfavorable
growth, or "true relapse" due to the placement of
the teeth in an unstable position (4).
Reitan (5) in 1967 showed that periodontal
ligament takes 232 days to reorganize and can
derotate teeth after one years. The periodontal
ligament requires three to four months'
masticatory stimulation for organization of its
fibers.
(1) Lecturer, Department of Orthodontics, Dental College,
In addition, research has shown that alveolar bone
is laid down after one month and supracrestal
fibers require one year to remodel, therefore,
retention and relapse are considered as vital issues
of a complete and a successful orthodontic
treatment (2). There are literatures on retention and
post-treatment relapse, which have been reviewed
in some depth (5-8).
In orthodontic, there are grossly two types of
orthodontic retainers: removable (commonly
temporary), and fixed (commonly permanent) (911)
. A temporary retainer is designed for a
relatively limited retention period to allow for the
reorganization of the gingival & periodontal
tissues (8).
Henry Baker used maxillary and
mandibular vulcanite removable retainers with
labial wires, but the vulcanite was not adapted to
the teeth. Instead, the teeth were prevented from
moving lingually by metallic spurs embedded in
the vulcanite (12). The retainers of Chartes A.
Hawley (13) in 1919 were an improvement over
Baker's in that the base material was flowed
against the lingual surfaces, thus helping to
prevent rotations. In 1930s, vulcanite was
replaced by acrylic, and till now the orthodontists
are using the Hawley retainer and its many known
modification (12-14). The invisible retainers was
Vol. 24(2), 2012
developed by Robert Pointz (15) in 1971, later on
Essix retainers were introduced by Sheridan et al
(16)
in 1993. Typically such invisible retainers are
formed from a sheet of thin Biocryl™, or other
similar material that is heated & formed by
suction or pressure on to a work model of the
dentition (15-18).
The purpose of the current study was to evaluate
the new Clear Advantage Series II durable
retainer and compare the clinical performance of
such retainer with the most standard types of
retainers (convention Clear Advantage Series I
thermo-vacuum formed invisible retainer,
Hawley, and the fixed lingual bonded retainers).
SUBJECTS AND METHODS
Twenty finished fixed orthodontic patients
attended a private clinic in Baghdad city, starting
the retention phase were selected from 29 patients
after discussion the study with them from ethical
approval point of view, and only those willing to
provide complete co-operation were enrolled in
the study and fully informed consents were taken,
the twenty patients were divided into four groups.
Each group consisted of five patients (3 females
and 2 males), mean age ranged 18-30 years old.
Patient exclusion criteria:
1. Craniofacial anomalies, symptoms of temperomandibular joint disorders, history of
orthognathic surgery, or bad habits.
2. Unsatisfied patients to the final orthodontic
fixed treatment objectives.
3. Unavailable patients for long term (1 year)
follow-up evaluation.
Methodology: The treatment protocol was as
follow:
All participants were previously treated with
Roth system upper and lower fixed orthodontic
appliances (Bracket's slot size 0.022", Pyramid
Orhodontics, CA; USA). An alginate impressions
(Tropicalgin-normal setting Zhermack ®; Italy)
were taken by assorted sizes rim lock trays
(Frontier Dental Industrial Co., China) for the
patients' upper and lower dental arches then
poured with type four thixotropic die stone (Elite
Stone - Zhermack; Italy) after considering the
manufacturer instructions. All retainers were
fabricated by the same private laboratory.
Members of the first group were given the new
thermo-vacuum formed invisible Clear Advantage
Series II durable retainer material, thermal
forming coping polypropylene; 0.040 of an inch
(OrthoTechnology-Tampa, Florida; USA). While
the second, third, and fourth groups were given
standard thermo-vacuum formed invisible Clear
Advantage
Series
I
thermal
forming
splint/copolyester retainer material; 0.040 of an
inch (OrthoTechnology-Tampa, Florida, USA),
Hawley retainer fabricated with polymethylmethacrylate "powder and liquid" (Orthocryl®,
Dentaurum, Ispringen, Germany) and 0.7mm
hard stain-less steel wire (Dentaurum, Ispringen,
Germany), and fixed lingual bonded retainers
"cuspid to cuspid" with assorted sizes (Ortho
Matrix; USA) bonded with light activated
orthodontic bonding system (Resilience ®, Ortho
Technology-Tampa, Florida; USA), respectively,
the retainers' materials were shown in figure 1.
The Clear Advantage Series II thermo-vacuum
formed durable invisible retainer, the Clear
Advantage Series I thermo-vacuum formed
standard invisible retainer, and the fixed bonded
lingual retainer were placed on the same day as
the fixed appliances were removed, while the
Hawley retainers were placed one to seven days
after the removal of the fixed appliances, the four
types of retainers were shown in figures 2 to 5.
Ten variables were applied on the twenty
patients to evaluate the clinical performance of the
four retainers' types, the ten variables were
evaluated and judged by the operator with the
patient as three non-parametric categorical
descriptions: superior (+), acceptable (±), and
inferior (-) properties, these ten variables were.
1. Versatility: it indicates the adaptability and
comfort of the patient to the retainer.
2. Aesthetic: It means the beauty and the
invisibility of the retainer.
3. Speech: It indicates the effect of the retainer
on speech.
4. Retention: It indicates the stability of the
retainer during rest and animation.
5. Bad taste and odor: It refers if the retainer
produces a bad taste and smell.
6. Caries risk: It refers to the hygienic property of
the retainer.
7. Soft tissue irritability: It refers to the ability of
the retainer to produce irritation to the soft
tissue (gingival, lip, cheek, and tongue).
8. Construction times: It refers to how much time
does it need to construct the appliance till
insertion inside the patient's mouth, noted as
superior (short time), acceptable (intermediate
time), and inferior (long time).
9. Chair-side time: It refers to how much time
does it need to place, fit, or bond the retainer at
each visit, also it involves the time needed for
repairing the appliance.
10. Failure of retention material: It refers to the
durability of the retainer's material inside the
patient's mouth. Without crack, perforation,
fracture, or debonding.
Vol. 24(2), 2012
The clinical performance of the new Clear
Advantage Series II durable thermo-vacuum
formed invisible retainer was evaluated at the time
of retainer insertion, three months, six months,
and one year post-insertion follow-up (19,20) in
comparison with the three of the most standard
and commonly used retainers; convention Clear
Advantage Series I thermo-vacuum formed
invisible retainer, Hawley, and the fixed lingual
bonded retainers.
All patients received upper and lower retainers,
the invisible retainers were full coverage type, and
the patient should wear the removable retainer full
day time (except during meals for thermo-vacuum
formed retainers) for six months, and then at night
only for the next six months (21).
Statistical analysis: The data were collected and
subjected to computerized statistical analysis
using statistical Package for Social Science
computer software (SPSS, version 17), in which
the description for the non-parametric categorical
variables represented by observed number and
percentage of occurrence, while the inferential
statistics included the use of Chi-square for
comparison of the categorical data among the four
types of retainers. Probability levels of less than
5%, 1%, and 0.1% were regarded as statistically
significant, highly significant, and very highly
significant, respectively.
Method error: It was calculated to determine the
reproducibility and reliability of the categorical
descriptions of clinical performance, the
categorical descriptions of five patients were
evaluated two times, first by the researcher, and
second time by another observer. Kappa test
(GraphPad Software, Inc.; USA) was used to
evaluate the inter-observer agreement, it was
found equal to 0.8 which indicates a very good
strength of agreement. (4,22).
RESULTS AND DISCUSSION
There are insufficient data on which to base our
clinical practices on retention present, several
retainer designs have examined over time, with
various retention protocols to minimize relapse
(19,23-25)
. Because of the lack of scientific evidence
on retention protocols, it appears that previous
recommendations are based largely on personal
preference and non-scientific criteria (4,25). The
clinical performance of different retainers' types is
a vital area of orthodontic research, and it should
be given priority on our concern. As far as being
aware, no research has been published that
addresses the evaluation of the clinical
performance of different retainers' types.
Many studies conducted onto survey the
orthodontic trends over the past 25 years in
Australia, New Zealand, United States and United
Kingdom to identify consistencies in retention
procedures and found that the most commonly
used retainers were invisible retainers (vacuumformed) and canine to canine bonded lingual
retainers. Hawley retainers declined in use from
1986 to 2011, whereas invisible retainers and
fixed bonded canine to canine retainers increased
(25-28)
. Therefore, in the current study, the new
retainer (Clear Advantage Series II durable
retainer) was compared with the most commonly
used retainers in orthodontics (standard thermovacuum formed invisible retainer, Hawley, and
fixed bonded lingual retainers). On the other
hand, it is very important to explain fully the
importance of retainers and of proper handling
and regular checkups to patients (4). Patients need
to be recalled after different time intervals in
order to instruct, checkup, adjust, and remove any
discomfort, therefore, in the current study,
different time intervals ( At time of retainer
insertion, three months, six months, and one year
post-retainer insertion) were selected to evaluate
the clinical performance of these retainers (19,20).
Tables one to four described the variables'
characteristics of clinical performance. Regarding
the versatility (comfort and adaptability), the
Clear Advantage Series II durable invisible
retainer (CII) showed that there was an inferior
categorical description property expressed by a
low observed numbers and percentages of
occurrence at the time of retainers insertion, the
superior and acceptable categorical descriptions
increase after three months, then became the same
description after six months and one year postretainer insertion, while the Clear Advantage
Series I standard thermo-vacuum
formed
invisible retainer (CI) showed an increase in the
superior and acceptable categorical descriptions
from the time of insertion to three months postinsertion, this may be due to adaptation of
stomatognathic system to the new appliance
inserted inside the patient's mouth, the inferior
description increases from six months to one year
post-insertion, this may be due to cracks produced
at the margins of the retainer that can reduce the
adaptation and comfort of the patient to this type
of retainer. The Hawley retainer (HR) showed an
increase in the superior and acceptable categorical
descriptions from time of insertion to the three
months post-insertion due to the adaptation
process, while the inferior description increases
from six months to one year post-insertion, this
may be due that such type of retainer contains
thick and bulk acrylic base plate and orthodontic
wires that are liable to deformation and need
periodic adjustment, so the versatility decreased
Vol. 24(2), 2012
with time, so that it will negatively affect the
adaptation and comfort. The fixed bonded lingual
retainer (FR) showed an increase in the superior
categorical description with time, this may also be
due to adaptation of the tongue to the fixed
bonded lingual retainer.
Regarding the esthetic point of view the CII,
CI, and FR showed high observed numbers and
percentages of occurrence for superior and
acceptable
descriptions, this is due to the
translucent property of clear invisible (CII and CI)
retainers, even though the CII retainer is slight
cloudy than the CI retainer, but when the CII
retainer is subjected to heat during thermal
vacuum forming process, such cloudiness is
decreased and became unnoticeable when the CII
is inserted inside the patient's mouth, so both
types of clear invisible (CII and CI) retainers
exhibited superior and acceptable properties, the
fixed bonded lingual retainer (FR) was positioned
lingually, therefore it exhibits better esthetic,
while the HR showed an increase of the superior
and acceptable categorical descriptions with time,
this may be due to better
psychological
adaptation to the shape of this retainer.
Regarding the speech, all types of retainers
showed increase in the superior and acceptable
categorical descriptions with time due to the
adaptation of the patient's tongue and lips to the
retainers with time factor, so phonetic
improvement will occur.
Regarding the retention, the CII and CI
retainers showed superior categorical description,
and not affected by time, because these retainers'
types depend on negative pressure, accurate
fitness, and interfacial forces to achieve their
retention (3,4,23), while the HR showed increase in
the inferior categorical description with time
because such type of retainers had wires that need
periodic adjustment, the FR showed also increase
in the inferior property with time, this may be due
to the increase of the bonding failure of FR with
time, which can subsequently affect the overall
retention of this type of retainer.
Regarding the bad taste, the CII and CI
retainers showed superior categorical description
and not affected by the factor of time, while HR
showed inferior description at time of insertion,
this may be due to the residual monomer of
methyl methacrylate,
the inferior property
decreases after three months and six months postinsertion, then the inferior property will increase
after one year post-insertion, this may be due to
microbial plaque accumulation at the acrylic base
plate that can affect the taste and odor, this
explanation agreed with other research (8) , the FR
showed high inferior property at time of insertion,
due to the bad taste of the etchant and primer,
which can negatively affect the taste, then with
time there will be an increase in the inferior
property of bad taste and odor, due to unhygienic
plaque accumulation property of this type of
retainer (9,10).
Regarding the caries risk, all types of
removable retainers showed high observed
numbers and percentages of occurrence of
superior categorical description property and
remained high with time, except the FR showed
high inferior property with time because of
difficulty in maintaining good oral hygiene with
such type of retainer, while all removable
retainers can be removed outside the patient's
mouth, so it is better to perform a good oral
hygiene maintenance with such type of retainers
(9,10)
.
Regarding soft tissue irritability, CII and CI
retainers showed high observed numbers and
percentages of occurrence of the superior
categorical description property and remained the
same with time because both retainers' thickness
were one millimeter and contained no wires, so
less soft tissue irritability, while HR showed high
inferior property and remained the same observed
numbers and percentages after three months, six
months , and one year post-insertion, because this
type of retainers contained wires and relatively
thick bulky acrylic base plate that can affect on
the surrounding soft tissue. However, it is well
known that the major advantage of HR is the
ability of the patient to perform optimal oral
hygiene care, the major disadvantage of such
retainer is the acrylic base plate, which is
basically thick and bulky, such bulk affects
speech negatively, potentially toxic irritable and
unhygienic upon prolong wearing (8), some
authors said that HR allows vertical settling of the
teeth (29-31). But settling of teeth should be carried
out during the last phase of active treatment rather
than in the retention period (30-32), the FR showed
high observed number and percentage of the
inferior categorical property and both increase
with time, this may be due to the ability of this
type of retainer to cause irritation to the
surrounding soft tissue due to plaque retentive
ability, on the other hand, the major advantage of
the fixed retainer was the close relation between
the bonded teeth, resulting in their consolidation
to act clinically as a stable dental unit, such
consolidation maintains the position of the
dentition even in the presence of unfavorable or
unbalanced soft tissue forces (9,33).
Regarding the construction time, CII and CI
invisible retainers showed high superior
categorical property, because such retainers need
Vol. 24(2), 2012
about one hour from impressions till their
insertion inside the patient's mouth, while HR
showed high inferior categorical property because
it needs one to seven days till retainer insertion
because it needs a laboratory work, so it can be
concluded that the thermoplastic invisible
retainers (CII sand CI) showed a reduction in the
laboratory fabrication, and the fabrication
technique is simple and no technical proficiency
in wire bending or knowledge of the properties of
dental laboratory acrylic is required, this is in
accordance with other studies (16,18).
Regarding chair-side time, the CII retainer
showed the highest superior categorical property,
followed by CI, HR, and FR respectively, the
superior property remains high with time, because
CII retainer showed the most durable retainer, and
it does not need any repairing, subsequently less
chair-side time, while the other retainers' types
were more liable to repair, therefore, more chairside time, the FR showed an increase in the
inferior property with time, because it exhibited
more debonding failures and subsequently more
chair-side time. It might be better to assess and
compare the number of failures and rebonding
appointments, it might be that the increased
mobility of the teeth because of periodontal
problem in the post-treatment period favors
detachments, failures can be inherent, as a result
of poor chair-side technique, or acquired, from
wear or direct trauma to the retainer (34,35).
Regarding failure of retention material, the CII
retainer showed superior categorical property
because this type of retainer is most durable
retainer than other retainers' types, and it does not
be affected by the time factor, while the FR, CI,
and HR showed inferior categorical property
changing from high to low respectively, this may
be due to the multiple debonding failures of FR,
cracks and their propagation and subsequent
fracture of the margins of CI, and fracture of the
orthodontic wires and/or fracture of acrylic base
plate resulting in failure of the retainer,
respectively, as shown in tables one to four, so it
can be concluded that the CII retainer overcomes
the cracks and fracture problem often encountered
with the use of CI and HR retainers and
debonding failures associated with FR. There is
little doubt that corrosive wear is an important
factor in the durability of thermoplastic retainers,
chemicals and certain bicarbonated drinks can
plasticize certain polymers (polypropylene of CII,
and copolyesters of CI retainers), temperature
change of water inside patient's mouth can cause
filler leaching, and certain micro-organisms
produce esterase enzymes that can degrade
polymers(36,37) .
A comparison of the total variables of the
clinical performance at total time intervals using
chi-square showed that there was a significant
difference (P<0.05) in the acceptable categorical
description between CII and CI, as demonstrated
in table 6, this may be due to the significant
difference of the acceptable categorical
description between CII and CI retainers after 3
months post-retainer insertion as shown in table 5,
which it plays an important role in the final
difference between the two types of retainers as
shown in table 6, while a clinical performance
comparison between CII, HR, and FR showed
very high significant difference (P<0.001)
between all categorical descriptions of these
variables for total time intervals, this may be due
to the very high significant difference of the
acceptable categorical description property
between CII, HR, and FR retainers after 3 months,
6 months, and 1 year post-insertion as shown in
table 5, so it can be concluded that the new CII
retainer seems to have several advantages when
compared to the three standard orthodontic
retainers (CI, HR, and FR). Taking into
consideration, the main positive and negative
aspects of the four types of retainers used in the
current study, it was thought that a combination of
removable, comfortable, aesthetic, better speech,
superior retention, relatively not producing bad
taste and odor, hygienic, least soft tissue
irritability, superior construction and chair-side
time, and durable, will be more favorable
appliance to both the patient and the orthodontist.
However, the major disadvantage of the new CII
retainer was that it does not bond to acrylic
because polypropylene material of this type of
retainer is considered as a non-stick plastic,
basically it has inert or inactive molecular
structure, therefore described as a low energy
state (29). There was a very high significant
difference (P<0.001) in the superior and inferior
categorical properties and non-significant
difference (P>0.05) in the acceptable categorical
description property between CI, HR, and FR for
total time of the total variables of clinical
performance, as shown in table 6, this may be due
to the non-significant difference in the acceptable
categorical description between CI, FR, and HR
after 6 months, and one year post-insertion,
respectively, for total variables of clinical
performance as described in table 5. So it can be
concluded that the overall clinical performance
comparison between CI retainer and HR is as the
same as that between CI and FR, as demonstrated
in table 6. There was a non-significant difference
(P>0.05) between HR and FR for all categorical
descriptions at total time intervals, so it can be
Vol. 24(2), 2012
concluded that HR and FR also exhibited the
same overall clinical performance. In addition, it
was found that patients were compliant with all
types of retainers, and the compliance decreased
at a much faster rate with both types of themovacuum formed retainers (CII and CI ) than with
HR and FR. As a conclusion, patient's compliance
is greater with HR and FR retainers than with CII
and CI retainers, this agreed with other researches
(25,38)
.
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25. George K, James K, David F, David A, Pratt M.
Evaluation of retention protocols among members of
the American Association of Orthodontists in the
United States. Am. J. Orthod. Dentofac. Orthop. 2011;
140(4):520-526.
26. Keim RG, Gottkieb EL, Nelson AH, Vogels DS.
Study of orthodontic diagnosis and treatment
procedures, part one: results and trends. J. Clin.
Orthod. 2008; 42:625-40.
27. Renkema AM, Sips ET, Bronkhorst E, Kuijpers AM.
A survey on orthodontic retention proceduesin the
Netherlands. Eur. J. Orthod. 2009; 31: 432-7.
28. Singh P, Grammati S, Krischen R. Orthodontic
retention patterns in the United Kingdom. Eur. J.
Orthod. 2009; 36: 115-21.
29. Uhde MD. Sadowsky C, Be Gole E. Long term
stability of dental relationships after orthodontic
treatment. Angle Orthod. J. 1983; 53:240-252.
30. Razdolsky Y, Sadowsky C, Be Gole E. Occlusal
contacts following orthodontic treatment: A follow up
study. Angle Ortho. J. 1989; 59: 181- 185.
31. Alexander KJ. Treatment and retention for long-term
stability. WB Saunders Company, Philadelphia, 1993;
p: 115-133.
32. Dincer M, Aslan BI. Effects of thermoplastic retainers
on occlusal contacts. Eur. J. Orthod. 2010; 32: 6-10.
33. Renkema AM, Renkema AL, Bronkhorst G, Katsaros
C. Long-term effectiveness of canine to canine bonded
flexible spiral wire lingual retainers. Am. J. Orthod.
Dentofac. Orthop. 2011; 139(5):614-621.
34. Stormann J, Ehmer U. A prospective randomized
study of different retainer types. J. Oro. Fac. Orthop.
2002; 63(1):42-50.
35. Lie SF, Ozcan M, Verkerke GJ, Sandham A, Dijkstra
PU. Survival of flexible braided and bonded stainless
steel lingual retainers. A historic Cohort study. Eur. J.
Orthod. 2008; 30(2):199-204.
36. Richard VN. Introduction to dental materials. 3rd Ed
Edition, Elsevier Science Limited 2007; p:33.
37. Soderholm KJ, Richards ND, Wear resistance of
composites, a solved problem? Gen. Dent. 1998; 46:
256-63.
38. Pratt M, Kluemper G, Lindstrom A. Patient
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phase. Am. J. Orthod. Dentofac. Orthop. 2011;
140:196-201.
Vol. 24(2), 2012
Figure 1: Retainers' materials, A: Clear
Advantage Series II durable retainer material,
B: Clear Advantage Series I retainer material,
C and D: Polymethyl-methacrylate "powder
and liquid" and 0.7mm hard stain-less steel
wire for fabrication of Hawley retainer, E and
F: Fixed lingual bonded retainers "cuspid to
cuspid" with assorted sizes bonded with light
activated orthodontic bonding system.
Figures 2 A - E: The Clear Advantage Series II
thermo-vacuum formed durable invisible retainer.
Figure 3: Clear Advantage Series I thermovacuum formed invisible
Figure 4: Hawley retainer inside a patient's mouth.
retainer.
Figure 5: Fixed lingual bonded retainers "cuspid to cuspid"
Vol. 24(2), 2012
Table 1: Descriptive statistics for the clinical performance evaluation of the four types of
retainers at the time of insertion using observed numbers and percentage of occurrence.
Versatility
Aesthetic
Speech
Retention
Bad taste and
odor
Caries risk
(Hygienic)
Soft tissue
irritability
Construction
Time
Chair- side
time
Failure of
retention
material
Total variables
Clear Advantage Series II
Durable invisible retainer
N=5
±
+
1
3
1
(20%)
(60%)
(20%)
5
0
0
(100%)
(0%)
(0%)
1
3
1
(20%)
(60%)
(20%)
4
1
0
(80%)
(20%)
(0%)
5
0
0
(100%)
(0%)
(0%)
Clear Advantage Series I
standard invisible retainer
N=5
±
+
1
3
1
(20%)
(60%)
(20%)
5
0
0
(100%)
(0%)
(0%)
1
3
1
(20%)
(60%)
(20%)
4
1
0
(80%)
(20%)
(0%)
5
0
0
(100%)
(0%)
(0%)
Hawley retainer
N=5
+
0
(0%)
0
(0%)
0
(0%)
4
(80%)
1
(20%)
±
1
(20%)
1
(20%)
0
(0%)
1
(20%)
2
(40%)
4
(80%)
4
(80%)
5
(100%)
0
(0%)
2
(40%)
Fixed bonded lingual
retainer
N=5
±
+
0
1
4
(0%)
(20%)
(80%)
5
0
0
(0%)
(0%)
(100%)
0
1
4
(0%)
(20%)
(80%)
5
0
0
(100%)
(0%)
(0%)
1
1
3
(20%)
(20%)
(60%)
-------
-------
-------
-------
-------
-------
-------
-------
-------
-------
-------
-------
5
(100%)
5
(100%)
5
(100%)
0
(0%)
0
(0%)
0
(0%)
0
(0%)
0
(0%)
0
(0%)
5
(100%)
5
(100%)
5
(100%)
0
(0%)
0
(0%)
0
(0%)
0
(0%)
0
(0%)
0
(0%)
1
(20%)
0
(0%)
5
(100%)
1
(20%)
1
(20%)
0
(0%)
3
(60%)
4
(80%)
0
(0%)
1
(20%)
1
(20%)
0
(0%)
2
(40%)
3
(60%)
1
(20%)
2
(40%)
1
(20%)
4
(80%)
-------
-------
-------
-------
-------
-------
-------
-------
-------
-------
-------
-------
31
(77.5%)
7
(7.55%)
2
(5%)
31
(77.5%)
7
(7.55%)
2
(5%)
11
(27.5%)
7
(7.5%)
22
(55%)
13
(32.5%)
9
(22.5%)
18
(45%)
+ : Superior .
± : Acceptable.
- : Inferior.
N: Number of subjects.
retainers after three months post- insertion using observed numbers and percentage of
occurrence.
Versatility
Aesthetic
Speech
Retention
Bad taste and
odor
Caries risk
(Hygienic)
Soft tissue
irritability
Construction
Time
Chair- side
time
Failure of
retention
material
Total variables
N=5
±
+
4
1
0
(80%)
(20%)
(0%)
5
0
0
(100%)
(0%)
(0%)
3
1
1
(60%)
(20%)
(20%)
5
0
0
(100%)
(0%)
(0%)
5
0
0
(100%)
(0%)
(0%)
5
0
0
(100%)
(0%)
(0%)
5
0
0
(100%)
(0%)
(0%)
N=5
±
+
4
1
0
(80%)
(20%)
(0%)
5
0
0
(100%)
(0%)
(0%)
3
1
1
(60%)
(20%)
(20%)
5
0
0
(100%)
(0%)
(0%)
5
0
0
(100%)
(0%)
(0%)
5
0
0
(100%)
(0%)
(0%)
5
0
0
(100%)
(0%)
(0%)
Hawley retainer
N=5
+
1
(20%)
1
(20%)
2
(40%)
3
(60%)
1
(20%)
5
(100%)
1
(20%)
±
3
(60%)
1
(20%)
2
(40%)
2
(40%)
3
(60%)
0
(0%)
2
(40%)
1
(20%)
3
(60%)
1
(20%)
0
(0%)
1
(20%)
0
(0%)
2
(40%)
Fixed bonded lingual
retainer
N=5
±
+
1
1
3
(20%)
(20%)
(60%)
5
0
0
(100%)
(0%)
(0%)
0
2
3
(0%)
(40%)
(60%)
3
1
1
(60%)
(20%)
(20%)
1
2
2
(20%)
(40%)
(40%)
0
2
3
(0%)
(40%)
(60%)
1
3
2
(20%)
(60%)
(40%)
-------
-------
-------
-------
-------
-------
-------
-------
-------
-------
-------
-------
5
(100%)
0
(0%)
0
(0%)
1
(20%)
4
(80%)
0
(0%)
1
(20%)
4
(80%)
0
(0%)
1
(20%)
1
(20%)
3
(60%)
5
(100%)
0
(0%)
0
(0%)
1
(20%)
3
(60%)
1
(20%)
2
(40%)
2
(40%)
1
(20%)
2
(40%)
2
(40%)
1
(20%)
42
(93.3%)
2
(4.4%)
1
(2.22%)
34
(75.5%)
9
(20%)
2
(4.44%)
17
(37.7%)
19
(42.2%)
9
(20%)
14
(31.1%)
13
(28.8%)
18
(40%)
+ : Superior .
± : Acceptable.
- : Inferior.
N: Number of subjects
Vol. 24(2), 2012
retainers after six months post- insertion. using observed numbers and percentage of occurrence
Versatility
Aesthetic
Speech
Retention
Bad taste and
odor
Caries risk
(Hygienic)
Soft tissue
irritability
Construction
Time
Chair- side
time
Failure of
retention
material
Total variables
N=5
±
+
5
0
0
(100%)
(0%)
(0%)
5
0
0
(100%)
(0%)
(0%)
5
0
0
(100%)
(0%)
(0%)
5
0
0
(100%)
(0%)
(0%)
4
1
0
(80%)
(20%)
(0%)
5
0
0
(100%)
(0%)
(0%)
5
0
0
(100%)
(0%)
(0%)
N=5
±
+
2
2
1
(40%)
(40%)
(20%)
5
0
0
(100%)
(0%)
(0%)
5
0
0
(100%)
(0%)
(0%)
5
0
0
(100%)
(0%)
(0%)
4
1
0
(80%)
(20%)
(0%)
5
0
0
(100%)
(0%)
(0%)
5
0
0
(100%)
(0%)
(0%)
Hawley retainer
N=5
Fixed bonded lingual retainer
N=5
+
1
(20%)
2
(40%)
4
(80%)
3
(60%)
1
(20%)
5
(100%)
1
(20%)
±
3
(60%)
2
(40%)
1
(20%)
2
(40%)
3
(60%)
0
(0%)
2
(40%)
1
(20%)
1
(20%)
0
(0%)
0
(0%)
1
(20%)
0
(0%)
2
(40%)
+
1
(20%)
5
(100%)
0
(0%)
3
(60%)
1
(20%)
0
(0%)
1
(20%)
±
2
(40%)
0
(0%)
3
(60%)
1
(20%)
2
(40%)
2
(40%)
1
(20%)
2
(40%)
0
(0%)
2
(40%)
1
(20%)
2
(40%)
3
(60%)
2
(40%)
-------
-------
-------
-------
-------
-------
-------
-------
-------
-------
-------
-------
5
(100%)
0
(0%)
0
(0%)
3
(60%)
1
(20%)
1
(20%)
1
(20%)
4
(80%)
0
(0%)
0
(0%)
2
(40%)
3
(60%)
5
(100%)
0
(0%)
0
(0%)
1
(20%)
2
(40%)
2
(40%)
1
(20%)
3
(60%)
1
(20%)
1
(20%)
1
(20%)
3
(60%)
44
(97.7%)
1
(2.2%)
0
(0%)
35
(77.7%)
6
(13.3%)
4
(8.8%)
19
(42.2%)
19
(42.2%)
6
(13.3%)
12
(26.6%)
15
(33.3%)
18
(40%)
+ : Superior .
± : Acceptable.
- : Inferior.
retainers after one year post-insertion using observed numbers and percentage of occurrence.
Versatility
Aesthetic
Speech
Retention
Bad taste and
odor
Caries risk
(Hygienic)
Soft tissue
irritability
Construction
Time
Chair- side
time
Failure of
retention
material
Total variables
N=5
±
+
5
0
0
(100%)
(0%)
(0%)
5
0
0
(100%)
(0%)
(0%)
5
0
0
(100%)
(0%)
(0%)
5
0
0
(100%)
(0%)
(0%)
3
1
1
(60%)
(20%)
(20%)
5
0
0
(100%)
(0%)
(0%)
5
0
0
(100%)
(0%)
(0%)
N=5
±
+
2
1
2
(40%)
(20%)
(40%)
4
1
0
(80%)
(20%)
(0%)
5
0
0
(100%)
(0%)
(0%)
5
0
0
(100%)
(0%)
(0%)
3
1
1
(60%)
(20%)
(20%)
5
0
0
(100%)
(0%)
(0%)
5
0
0
(100%)
(0%)
(0%)
Hawley retainer
N=5
Fixed bonded lingual retainer
N=5
+
1
(20%)
3
(60%)
4
(80%)
1
(20%)
0
(0%)
1
(20%)
1
(20%)
±
3
(60%)
1
(20%)
1
(20%)
2
(40%)
3
(60%)
4
(80%)
2
(40%)
2
(40%)
1
(20%)
0
(0%)
2
(40%)
2
(40%)
0
(0%)
2
(40%)
+
2
(40%)
5
(100%)
0
(0%)
3
(60%)
0
(0%)
1
(20%)
0
(0%)
±
2
(40%)
0
(0%)
3
(60%)
1
(20%)
2
(40%)
1
(20%)
2
(40%)
1
(20%)
0
(0%)
2
(40%)
1
(20%)
3
(60%)
3
(60%)
3
(60%)
-------
-------
-------
-------
-------
-------
-------
-------
-------
-------
-------
-------
5
(100%)
0
(0%)
0
(0%)
1
(20%)
2
(40%)
2
(40%)
1
(20%)
3
(60%)
1
(20%)
0
(0%)
1
(20%)
4
(80%)
5
(100%)
0
(0%)
0
(0%)
1
(20%)
1
(20%)
3
(60%)
1
(20%)
2
(40%)
2
(40%)
0
(0%)
1
(20%)
4
(80%)
43
(95.5%)
1
(2.2%)
1
(2.2%)
31
(68.8%)
6
(13.3%)
8
(17.7%)
13
(28.8%)
20
(44.4%)
12
(26.6%)
11
(24.4%)
13
(28.8%)
21
(46.6%)
+ : Superior .
± : Acceptable.
- : Inferior.
Vol. 24(2), 2012
Table 5: Comparisons of the total variables of the clinical performance among the four types of
retainers at different times using chi square
At time of
insertion
Total
variables
After 3months
post- insertion.
After 6 months
post- insertion
After 1 year
ost-insertion
Total
variables
Total
variables
Total
variables
+
±
_
+
±
_
+
±
_
+
±
_
CII and CI
x2
Sig.
0.000
NS
0.000
NS
0.000
NS
0.842
NS
4.454
S
0.332
NS
1.024
NS
3.070
NS
4.000
S
1.944
NS
3.570
NS
5.444
S
CII and HR
x2
Sig.
9.521
HS
0.000
NS
16.663
VHS
10.592
HS
13.760
VHS
6.400
S
9.920
HS
16.200
VHS
7.000
HS
16.070
VHS
17.190
VHS
9.306
HS
CII and FR
x2
Sig.
13.564
VHS
0.250
NS
17.64
VHS
14.000
VHS
18.066
VHS
15.210
VHS
18.284
VHS
12.250
VHS
18.000
VHS
18.962
VHS
10.284
VHS
18.180
VHS
CI and FR
x2
Sig.
13.564
VHS
0.250
NS
17.640
VHS
8.332
HS
0.726
NS
12.800
VHS
11.254
VHS
3.856
NS
8.908
S
9.522
HS
2.578
NS
5.826
S
HR and FR
x2
Sig.
0.472
NS
0.250
NS
0.022
NS
0.290
NS
1.124
NS
3.000
NS
1.580
NS
0.470
NS
4.840
S
0.166
NS
1.484
NS
2.454
NS
HR: Hawley retainer.
FR: Fixed bonded lingual retainer.
CII: Clear Advantage Series II Durable invisible retainer.
CI: Clear Advantage Series I standard invisible retainer.
+ : Superior .
± : Acceptable.
- : Inferior.
NS: Non-significant (P>0.05) .
CI and HR
x2
Sig.
9.521
HS
0.000
NS
16.663
VHS
5.666
S
3.570
NS
4.454
NS
4.840
S
3.380
NS
0.818
NS
7.362
HS
7.338
NS
0.800
NS
S: Significant ( P< 0.05).
HS: Highly significant (P<0.01).
VHS: Very highly significant (P < 0.001)
X2: Chi square.
Degree of freedom=1.
Table 6: Comparisons of the total time and total variables of the clinical performance among the
four types of retainers using chi square
Total
time
Total
variables
+
±
_
CII and CI
x2
Sig.
2.890
NS
7.810
S
7.200
NS
CII and HR
x2
Sig.
45.440
VHS
38.360
VHS
39.180
VHS
CII and FR
x2
Sig.
64.500
VHS
24.920
VHS
68.760
VHS
CI and FR
x2
Sig.
42.020
VHS
6.200
NS
42.660
VHS
HR and FR
x2
Sig.
2.141
NS
1.940
NS
6.920
NS
HR: Hawley retainer.
FR: Fixed bonded lingual retainer.
CII: Clear Advantage Series II Durable invisible retainer.
CI: Clear Advantage Series I standard invisible retainer.
+ : Superior .
± : Acceptable.
- : Inferior.
NS: Non-significant (P>0.05) .
CI and HR
x2
Sig.
26.380
VHS
4.720
NS
17.500
VHS
S: Significant ( P< 0.05).
HS: Highly significant (P<0.01).
VHS: Very highly significant (P < 0.001)
X2: Chi square.
Degree of freedom=3.
Vol. 24(2), 2012
Stimulation of rabbit
Stimulation of rabbit condyle growth by using pulsed
therapeutic ultrasound (A radiographical and histological
experimental study)
Mustafa A.Qaisi, B.D.S. (1)
Nidhal H. Ghaib, B.D.S., M.Sc. (2)
ABSTRACT
Backgrounds: Many difficulties faced the orthodontic clinician during treatment of class II malocclusion cases in the
preadolescence period in which treatment is done by growth modification of condyle , these difficulties are due to
the poor cooperation of the patients with the myofunctional appliances. The present research was carried out to
evaluate the effect of Low Intensity Pulsed Ultrasound application on mandibular condyle of rabbit radiographically
and histologically to evaluate the use of low intensity pulsed ultrasound in condyle growth modification in the
treatment of skeletal class II malocclusions in the growth period.
Materials and Methods: The sample was 15 New Zealand male rabbits in which Therapeutic Ultrasound was applied
to the left condyle (treated group) for 28 days while the right condyle was without ultrasound application (controlled
group), After animal sacrifying , the rabbit mandibles were dissected into two hemi mandible, left (treated) and
right (control), radiographic image for each hemi mandible was done and three linear measurements were made,
(Ramus height, condylar height and mandibular height). Then these hemi mandibles examined histologically
including calculating chondrocyte number, osteocyte number, cartilage area calculation and subchondral bone
area measurements.
Results: the results showed: The increasing of all linear measurements as a result of enhancement of chondrocytes,
osteocytes, increase of cartilage area and bone area in the treated group. There is significant correlation between
all linear measurements and chondrocyte and cartilage area.
Conclusion: low intensity pulsed ultrasound can accelerate condyle cartilage growth.
Key Words: therapeutic ultrasound, Low intensity pulsed ultrasound, condyle, growth modifications. (J Bagh Coll
Dentistry 2012;24(2):137-143).
INTRODUCTION
Class II malocclusions of skeletal origin are
routinely seen in the orthodontic office. Studies
of the etiologic factors of Class II malocclusions
recognize that most Class II malocclusions are a
result of mandibular deficiency and not of
maxillary excess (1). Most Class II patients
present with retrognathic mandibles and
orthognathic maxillae. Patients with mandibular
deficiency and Class II malocclusion have a
spectrum of esthetic, skeletal, and occlusal
characterstics (2,3). However, treating such
malocclusions in growing patients by using bitejumping appliances is believed to produce
satisfactory improvement in facial esthetics and
minimize the need for surgical intervention later.
There is evidence that compensatory growth
occurs at the tempromandibular joint, and
especially the mandibular condyle in response to
altered occlusal function in growing animals (4,5).
Rabie et al. (6) studied osteogenesis in the
glenoid fossa in response to mandibular
advancement. They reported that mandibular
protrusion resulted in the osteoprogenitor cells
being oriented in the direction of the pull of the
posterior fibers of the disk (viscoelastic pull) and
also resulted in a considerable increase in bone
formation in the glenoid fossa.
(1) M.Sc. Student, Department of Orthodontics, Dental College,
(2) Professor, Department of Orthodontics, Dental College,
Ultrasound is a form of mechanical energy that is
transmitted through and into biological tissues as
an acoustic pressure wave at frequencies above
the limit of human hearing, is used widely in
medicine as a therapeutic, operative, and
diagnostic tool. Therapeutic US, and some
operative US, use intensities as high as one to
three W/cm2 and can cause considerable heating
in living tissues. To take full advantage of this
energy absorption, physical therapists often use
such levels of US acutely to decrease joint
stiffness, reduce pain and muscle spasms, and
improve muscle mobility (7,8). Low–intensity
pulsed US (LIPUS) has been reported to be
effective in angiogenesis enhancement during
wound healing. Recently, low-level therapeuticpulsed US was used to enhance bone healing
after fracture and after mandibular distraction
osteogenesis.(9-11).LIPUS is a type of ultrasound
that promotes tissue healing. For such use, US is
administered in pulses at lower intensity levels
than in physiotherapy (0.5 to 3.0 W/cm2), below
0.1 W/cm2 (12) The mechanisms involved in this
process which include mechanotransduction of
micromechanical stimuli, will increase local
angiogenesis and improved blood supply and
aggrecan gene expression (13-15). LIPUS has also
been used on growing cartilage. This stimulus
has been effective increasing cartilaginous
growth potential in primary and secondary
Vol. 24(2), 2012
cartilage (16,17, 18). El-Bialy et al (17,18) applied
LIPUS (30 mW/cm2, 1.5 MHz) (Exogen Device)
on the temporomandibular joint (TMJ) region of
growing rabbits and baboon monkeys for 20
minutes daily. Their results show a significant
increase in mandibular cartilaginous growth
under LIPUS stimulation, especially under
chronic
mandibular
advancement.
The
mechanisms that may favor growth could include
the same mechanisms involved when bone
healing is enhanced with LIPUS.
zirconate –titnate transducer and consisted of a
200 –microsecond burst of 1 MHz sine that
delivered 50 mW/cm2 (model: HEALOSONIC,
New Delhi, India) (17,19,20) (Fig1), After four
weeks, all waves animals were sacrificed
humanly by intravenous injection of 1 mL/kg
sodium pentobarbitone, The mandibles were
surgically removed, divided at the symphyseal
junction into 2 hemi mandibles by straight hand
piece (Fig 2).
The materials used in this study could be
classified into three major categories; the
pharmacological materials, materials used for
radio graphical examination and the materials
used for the preparation of histological sections.
The sample consisted of 15 male New
Zealand - white rabbits of 10-11 weeks of age
and the rabbits were kept in the animal
department of National Center for Drug Control
and Research/Baghdad-IRAQ in separate cages
in a 12-hour light/dark environment at a constant
temperature of 23°C and provided with food and
water ad libitum. The health status of each rabbit
was evaluated by a day body weight monitoring
for two week before start of the experiment as
well as during the time of the experiment.
According to the ultrasound application protocol,
the mandibles in each rabbit were divided into
two groups:
1-Control group (non treated group): which
was the right side of the mandible
(right
condyle).
2-Ultrasound group (treated group):
in
which LIPUS of 50 mW/cm2 intensity ,1 MHz
frequency was applied for 20 minutes /day for
four weeks to the left side (left condyle) of the
mandible in each rabbit.
All rabbits were adapted to their cages
environment for two weeks before experiment.
On the day before experiment, each rabbit was
shaved in his left condyle region , This procedure
was repeated every four days to ensure that the
condyle area will be totally shaved along the
total period of experiment, the application of
LIPUS was done after sedation of rabbits by
using intramuscular injections of xylazine (2
mg/kg) , ultrasound transducer was attached
securely to the surface of the shaved condyle
with turnica, ultrasound gel was used to couple
the ultrasound energy between transducer and
skin surface, This procedure was repeated for 20
minutes/ day for four weeks in which pulsed
ultrasound waves were applied by conventional
therapeutic ultrasound device of 3-cm lead
Figure 1: Application of LIPUS
A
B
C
Figure 2: A-Surgical removal of mandible
B- Right hemi mandible
C- Left hemi mandible
Vol. 24(2), 2012
A
Figure 3: A- tracing of a hemi mandible
showing linearmeasurements taken to
evaluate differential mandibular growth
changes(17) B- tracing of left hemi mandible
by using Auto Cad
All hemi mandibles were radiographed with the
X-ray machine, transferred to the laptop by
making photographic picture to it using digital
camera (Sony Cyber shot) ,then each hemi
mandible was traced using (auto cad 2008)
program (with control of magnification by rod as
standardization).The x ray tracing identified three
anatomic points. Three anatomic parameters, two
representing anteroposterior mandibular length
and one representing mandibular ramus height,
were evaluated on the tracing of each hemi
mandible .The points and plane and
measurements are shown in (Fig3) and are listed
below (17):
1. Measuring points
• Infradentale: most anterior point on alveolar
process below the mandibular central incisor.
• Condylar point: most superior point on the
mandibular condylar summit.
• Angular process: the most posterior contour
on the mandibular ramus.
2. Planes and measurements
• Mandibular plane: a tangent to the inferior
border of the mandible.
• Condylar height: the distance measured
between the condylar point and the angular
process.
• Ramus height: the perpendicular distance
from condylar point to the mandibular plane.
• Mandibular height: the distance from
condylar point to infradentale.
After rabbits were sacrified, the surgically
dissected hemi mandibles were embedded in
10% buffered formalin for two weeks for fixation
and then decalcified using a solution containing
B
50% formic acid and 20% sodium citrate. The
condylar head and necks were embedded in
paraffin, then 5 µm thick sections were cut in the
sagittal plane with microtome, The tissue
sections were mounted on glass slides to be
stained with hemotoxylin and eosin, The finished
slides were examined using microscope and
photomicrographs were taken at 40x power after
placing an eye piece with a grid to calibrate the
measurements, Then the photomicrographs were
transferred to computer software (Auto Cad
2008). A calibration step was performed within
the software to get the actual measurements.
At the slide photomicrograph of the condylar
head, two sections were chosen for histological
examination (anterior and posterior sections for
each condyle) in way that ensure about all
condyle surface is measured, A subchondral
rectangular area of 2 mm2 was selected for all
slides and subsequent measurements and counts
were performed within anterior and posterior
sections which are represented by (Fig 4,5):1- Number of chondrocytes.
2- Number of osteocytes.
3- Cartilage thickness area.
4- Bone area.
5- Bone marrow area.
The first two were counted manually, while the
cartilage area, bone area and marrow area were
calculated by the (Auto Cad 2008) software after
tracing of it manually. From tracing, the cartilage
area was obtained, while for bone area it was
obtained by subtraction of marrow area form the
whole 2mm2 subchondral area (18).
Vol. 24(2), 2012
Figure 4: histological examination of left condylar Figure 5: histological examination of Right
condylar cartilage
Cartilage
RESULTS
The results included descriptive, comparative
and correlation statistics for the anthropometrical
and histological variables, the descriptive
involved the mean and standard deviation of the
three anthropometrical variables and of the four
histological variables measured in this study,
while for the comparative statistics Student’s ttests for independent groups were performed, and
a significance level of P , .05 was selected.
Statistical analysis was done, using SPSS
(version 15) software. As shown in (Table 1,2)
1-For the anthropometrical there was a
significant increase in the mandibular ramus
height condylar height and mandibular height in
the US-treated hemi mandibles compared with
the untreated hemi mandibles. Enlarged condyles
and increased ramal height were clearly observed
in the US-treated sides compared with the
nontreated sides (Figure 2 A).
2-For the histological variables there was
significant increase in the mean values of
chondrocytes number, Osteocytes number,
Cartilage thickness area and Bone area in the UStreated condyle Compared with the untreated
condyles.
For the correlation statistics between histological
and anthropometrical variables, there was
significant correlation between mandibular height,
condylar height and ramus height with chondrocyte
numbers and cartilage area in the US treated hemi
mandible while the anthropometric parameters did
not show significant correlation with histological
measurements in the right control side, except there
was indirect significant correlation between ramus
height and bone area (Table 3, 4).
Table 1: Descriptive & Comparative statistics for saggital jaw linear measurements
Variables
Sagittal
jaw linear
parameters
(mm)
MH*
CH*
RH*
US treated (Left ) hemi
mandibles (N=15)
Mean
±SD
52.06
1.33
18.96
0.48
31.89
MH= Mandibular Height,
0.83
Control (Right) hemi
mandibles (N=15)
Mean
±SD
49.97
1.59
17.18
1.15
Linear difference
(t-test)
t
D.F
P
3.889 28
0.001**
5.498 28 0.000***
29.54
4.696
CH= Condylar Height,
1.755
RH= Ramus Height
28
0.000***
Vol. 24(2), 2012
Table 2: Descriptive & Comparative statistics for Histological examination
US treated (Left )
condyle(N=15)
Mean
±SD
473.53
35.49
363
42.75
1.66
0.036
Histological
variables
Chondrocyte No.
Osteocyte No.
Bone area (mm2)
Cartilage thickness area
(mm2)
0.21
Control (Right) condyle
(N=15)
Mean
±SD
345.86
58.49
221.73
39.73
1.61
0.04
0.037
0.16
0.033
Histology difference
(t-test)
t
D.F
p
7.227 28 0.000***
9.373 28 0.000***
3.193 28
0.003**
3.763
28
0.001**
Table 3: Correlation analysis between the sagittal jaw linear measurements and Histological
measurements of the left hemi mandible
Variabl
e
MH
CH
RH
r
P
r
P
r
P
Chondrocyt
e
0.843***
0.000
0.565*
0.031
0.692**
0.004
Osteocyt
e
0.138
0.625
0.202
0.470
0.406
0.133
Bone
area
-0.131
0.641
-0.124
0.659
-0.239
0.391
Cartilag
e area
0.736**
0.002
0.570*
0.026
0.661**
0.007
Table 4: Correlation analysis between the sagittal jaw linear measurements and Histological
measurements of the right hemi mandible
Variable
MH
CH
RH
r
p-value
r
p-value
r
p-value
Chondrocyte
Osteocyte
Bone area
Cartilage area
0.063
0.823
0.061
0.830
0.247
0.374
0.450
0.092
0.374
0.169
0.437
0.104
- 0.497
0.059
- 0.368
0.177
- 0.578*
0.024
0.101
0.720
- 0.009
0.974
0.175
0.533
DISCUSSION
This study was performed primarily to find out
if there is any stimulatory effect of low intensity
pulsed ultrasound (LIPUS) on condylar cartilage
and on mandibular growth as a whole in growing
rabbits. The rabbit model was chosen for this
study because of the relatively large mandible
and skull. The age of rabbit was 10- 11 weeks
because in this age the rabbit is in growth spurt
(21)
, the device which was used is the
conventional Therapeutic ultrasound apparatus
that is adapted for LIPUS emission.
To date, the studies that have been published in
the orthodontic literature regarding the use of
LIPUS and its influence on condylar growth
have been performed using the standard LIPUS
device (Exogen, Caldwell, NJ)(17,18) , and this
device has been extensively proven in humans
(22)
and animals (16,23).
Despite this, other LIPUS emission settings
have been reported by using conventional
ultrasound devices (19) in which varying the
emission settings within the range of what is
defined as LIPUS. The results presented in the
use of conventional Ultrasound devices in these
animal studies were particularly interesting
because they pointed toward the biological
effects of LIPUS stimulation, in which using a
conventional LIPUS device which was able to
produce
US
emissions
of
appropriate
characteristics, as evaluated from the biological
response secondary to its use. This is reported by
Rodrigo et al., ( 2009)(24) study in which the
results suggested that the biological response
may vary and increase when LIPUS was applied
for 20 minutes instead of 10 minutes daily. The
amount of ultrasound transmission to the control
side was negligible in which the intercondylar
distance has been reported to be about four cm
producing negligible exposure to the condyle on
the other side (17)
The linear measurements of condylar height,
ramal height, and mandibular height were chosen
because previous studies on mandibular growth
in rabbits showed significant changes in the
ramal height and mandibular length in rabbits in
which the rabbit condyles growth selectively
inhibited by intra-articular papain injection(25).
The increase of all anthropometric measurements
Vol. 24(2), 2012
occurred due to the fact that ultrasound waves
can increase chondrogenesis (26, 27). The greatest
increase was in the condylar height measurement
and this could be due to the increase of cartilage
thickness in vertical dimension more than in
anterior and posterior dimension as most of
chondrocyte located in the larger upper surface
of condyle more than in the anterior and
posterior surfaces.
The previous study of the effect of pulsed
therapeutic ultrasound on rabbit condyle by (17)
revealed only the radiographical effect of
number in the left condyle may be due to the
increase in the vascularization which happened
due to the minimum thermal effect of ultrasound
that increase blood supply by blood vessels
dilations and due to non thermal effect in which
Ultrasound waves are
able to stimulate
mandibular Osteoblast to proliferate and produce
angiogenesis – related cytokines (28), All of these
factors will lead to increase osteocyte
nourishment which could increase the osteocyte
activity and maturation and formation of other
osteocyte .Also it could be as a result to the
increase of chondrocyte cells which will pass in
the different stages to form osteocytes (29). The
significant increase in treated side bone area may
be due to the effect of ultrasound which can
enhance FGF and VEGF (28), also ultrasound can
enhance the process of endochondral ossification
(16)
.Furthermore
Ultrasound
can
affect
Osteogenesis in which Osteoblasts can be
stimulated to increase collagen production and
increase the production of Prostaglandin E2
(30)
.and all of these factors are responsible for
bone matrix formation which will lead to
increase of bone area. Also, It probably occur
ultrasound on the condyle of rabbit. In the
present study, the aim was not to study the
radiographic effect alone but to clarify the
quantitive histological effect on rabbit condyle if
it present. the significant increase in the number
of chondrocytes in the US treated side could be
due to ultrasound wave effect by which it can
stimulate the chondrocyte proliferation and
chondrogenesis-associated gene expression(26,27),
which lead to increase the mesenchymal cells
differentiations to
chondroblasts then
chondrocytes. While the increase in osteocytes
due
ultrasound wave ability to change
permeability of chondrocytes leading to the
increase of intracellular level of Calcium in the
chondrocytes and increase in calcium
incorporation into differentiating cartilage and
bone cell cultures (31) and this can enhance the
mineralization of bone. the significant increase
in cartilage area in US treated side may be
happened due to the increase of extracellular
matrix of cartilage by the action of ultrasound
waves in the enhancement of FGF which are
responsible for fibroblast growth (28) also due to
increase in chondrocytes number , and that will
lead to increase collagen II, X type’s production .
The presence of significant correlation in left
condyle may be due to the increase in the
chondrocyte number which will lead to the
increase of extracellular matrix formation which
results in the increase of cartilage area. The
increase in cartilage thickness will effect on the
condylar point position and this in the end will
affect in a direct relation to all linear
measurements because all of these measurement
share the same condylar point.
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Vol. 24(2), 2012
The relation between W
The relation between W angle and other methods used to
assess the sagittal jaw relationship
Sara M. Al-Mashhadany, B.D.S, M.Sc. (1)
ABSTRACT
Background: This study aimed to evaluate the mean value for the W angle in Iraqi adults with a Class I, II, and III
skeletal relations and to verify the existence of sexual dimorphism, also to study the correlation between this angle
with the other methods (ANB, Wits appraisal, BETA angle, YEN angle) used for evaluation of the antero-posterior (AP)
jaw relationship.
Materials and methods: One hundred and fifty-two cephalometric radiographs of patients between the age of 18
and 25 years were selected. They were again subdivided into Classes I, II, and III groups on the basis of Beta angle,
Wits appraisal, and ANB angle, traced using AUTO CAD 2007. The W angle was measured between the
perpendicular from point M on S–G line and the M–G line. The mean and the standard deviation for the W angle
were calculated. Independent sample t- test, the one-way analysis of variance, LSD and Pearson correlation were
obtained.
Results: The results showed that a patient with a W angle between 51 and 56 degrees can be considered to have a
Class I skeletal pattern. With an angle less than 51 degrees, patients are considered to have a skeletal Class II
relationship and with an angle greater than 56 degrees, patients have a skeletal Class III and there is significant
difference in the mean value of W angle among the three skeletal patterns with a no gender difference. The W
angle had a negative significant relation with ANB in all three classes and with WITS appraisal in class III group, while it
had a positive significant relation with BETA and YEN angles in all the three skeletal relations.
Key words: W angle, Antero-posterior jaw relationship. (J Bagh Coll Dentistry 2012;24(2):144-149).
INTRODUCTION
In orthodontic diagnosis and treatment
planning, great importance has been attached to
evaluating the sagittal apical base relationship.
Both angular and linear measurements have been
incorporated into various cephalometric analyses
to help the clinician diagnose anteroposterior (AP)
discrepancies and establish the most appropriate
treatment plan(1). Since Wylie’s (2) first attempt
to describe AP jaw relationship, various other
cephalometric parameters have been proposed. Of
these parameters, the ANB angle (3) , the Wits
appraisal (4), and recently Beta angle (1) are the
commonly used parameters. Still, sagittal jaw
relationships are difficult to evaluate because of
rotations of the jaws during growth, vertical
relationships between the jaws and the reference
planes, and a lack of validity of the various
methods proposed for their evaluation (1, 4-6 ).
To determine true apical base relationship
independent of the cranial reference planes or
dental occlusion, Beta angle was developed(1).
The other problem is locating point condylion.
The reproducibility of the location of condylion
on mouth-closed lateral head films is limited (7- 9) .
Most recently introduced sagittal dysplasia
indicator is YEN angle (10). But since it measures
an angle between line SM and MG, rotation of
jaw because of growth or orthodontic treatment
can mask true basal dysplasia, similar to ANB
angle.
(1) Assistant Lecturer. Department of Orthodontics, College of
Dentistry, University of Baghdad
To overcome these existing problems, a
measurement was developed and named the W
angle. It is a new measurement for assessing the
skeletal discrepancy between the maxilla and the
mandible in the sagittal plane (Figure 1). It uses
three skeletal landmarks—point S, point M, and
point G—to measure an angle that indicates the
severity and the type of skeletal dysplasia in the
sagittal dimension (11).
The purposes of this study were to define the
mean value for the W angle in Iraqi adults with a
Class I, II, and III skeletal relations and to verify
the existence of sexual dimorphism, also to study
the correlation between this angle with the other
methods used for
evaluation of the anteroposterior (AP) jaw relationship.
To assign samples to the Classes I, II, and III
skeletal pattern groups, many files of individuals
between 18 and 25 years were screened in the
Orthodontic Department of Baghdad University.
After the initial selection, all x-rays were
traced using AUTO CAD 2007; the ANB and
Beta angles and the Wits appraisal were measured
by each investigator separately. The mean values
of those measurements were calculated.
For a patient to be included in the Classes I,
II, or III skeletal pattern group, criteria for Beta
angle along with one of two (ANB angle and Wits
appraisal) had to be met. A skeletal Class I
relationship was indicated by an ANB of 2–4
degrees, a Wits coincidence of AO and BO in
females or BO 1 mm ahead of AO in males, and a
Vol. 24(2), 2012
Beta angle of 27–35 degrees, Of the 70 patients
initially selected class I, only 54 met the criteria to
be included after retracing and remeasuring their
pretreatment caphalometric x-rays. Therefore,
Group I consisted of 54 patients 28 male, 26
female).
A skeletal Class II relationship was indicated
by an ANB of greater than 4 degrees, a Wits
appraisal with AO ahead of BO in females or AO
coinciding with or ahead of BO in males, and a
Beta angle less than 27 degrees, Of the 58 patients
initially chosen as Class II, 40 (18 female, 22
male) met the criteria .
The skeletal Class III individuals were
characterized by an ANB less than 2 degrees, a
Wits BO ahead of AO in females or BO ahead of
AO by more than 1 mm in males, and a Beta
angle greater than 35 degrees, Of the 65 patients
initially chosen as Class III, 58 (28 female, 30
male) met the criteria .
Cephalometric Bony Landmarks and lines
1. Point S (Sella): The midpoint of the
hypophysial fossa (12).
2. Point N (Nasion): The most anterior point on
the nasofrontal suture in the median plane (12).
3. Point A (Subspinale): The deepest midline
point on the premaxilla between the Anterior
Nasal Spine and Prosthion (13).
4. Point B (Supramentale): The deepest
midline point on the mandible between
Infradentale and Pogonion (13).
5. Point C (center of the condyle ):found by
tracing the head of the condyle and approximately
its center ( 1).
6. Point M: midpoint of the premaxilla (14).
7. Point G: centre of the largest circle that is
tangent to the internal inferior, anterior, and
posterior surfaces of the mandibular symphysis (14,
15)
.
8. N- A line: Formed by a line joining Nasion
and point A (13).
9. N- B line: Formed by a line joining Nasion
and point B (13).
10. Functional occlusal plane: drawn through the
cuspal overlap of maxillary first molar and
bicuspid (4).
11. Line connecting S and M points.
12. Line connecting M and G points
13. Line connecting S and G points.
14. Line from point M perpendicular to the S–G
line.
15. Line connecting C and A points.
16. Line connecting C and B points
17. Line connecting A and B points.
18. Line from point A perpendicular to the C–B
line.
Cephalometric measurements
1. ANB angle: The angle between lines N-A and
N-B. It represents the difference between SNA
and SNB angles or it may be measured directly as
the angle ANB (3, 16).
2. Beta angle: which is the angle between the
perpendiculare line from point A to C–B line and
the A–B line (1).
3. The YEN angle: which is the angle between
the M–G line and the M–S line (10).
4. The W angle: This is the angle between the
perpendicular line from point M to S–G line and
the M–G line (11).
5. AO-BO(mm):
the
distance
between
perpendiculars drawn from point A and point B
on to the occlusal plane (4)
Statistical analysis:
Collected data were subjected to a computerized
statistical analysis using SPSS version 15 (2006)
computer program. To summarize the data,
means, standard deviations, minimum and
maximum of W angle in three groups were
calculated, comparison between both genders is
done by using independent sample t-test. The oneway analysis of variance (ANOVA) was used
followed by LSD to determine whether there was
a statistically significant difference between the
mean values W angle of the three groups and
between each tow groups when there is significant
difference, Pearson’s correlation coefficient also
used to study the correlation between W angle and
ANB, YEN angle, BETA angle and Wits
appraisal.
In the statistical evaluation, the following level of
significance is used:
Non-significant
NS
P>0.05
Significant
* 0.05 ≥ P>0.01
Highly significant
** 0.01 ≥ P>0.001
Very highly significant *** P≤0.0001
RESULTS
The descriptive statistics of the five methods
used to assess the antero-posterior skeletal relation
in male and female groups and their gender
difference are shown in (table 1).
Table 2 shows the descriptive statistics including
mean , standard deviation, standard error ,minimum
and maximum for the total sample, also it shows the
comparison between the three skeletal relation using
f-test followed by LSD test to show the statistical
between each two skeletal pattern (table 3).
Table 4 reveals the correlation between W angle
and ANB, YEN angle, BETA angle and Wits
appraisal; Pearson’s correlation coefficient used
to study the correlation in each skeletal relation.
Vol. 24(2), 2012
DISCUSSION
Cephalometric radiograph is a valuable tool in
orthodontic diagnosis and treatment planning.
Even before Angle introduced his classification of
malocclusion to the profession in the early 1900s,
the anterposterior relationship of mandible to
maxilla was the most important diagnostic
criterion. This relationship can be determined
from clinical observation to some degree, but it
can be much more accurately evaluated from a
lateral radiograph (17).Assessing this sagittal
relationship is a challenging issue in orthodontics.
The ANB angle has been recognized as a skeletal
sagittal discrepancy indicator and has become the
most commonly used measurement since that
time. Steiner agreed with Reidel that SN plane
could be used as reference line because both
points are osseous structures that are easily visible
in lateral cephalogram (16).
More recently, it has been claimed that
the ANB angle is affected by several
environmental factors and thus a diagnosis based
on this angle may give false Results.
The following factors have been reported to affect
the ANB angle:
• The patient’s age.
• The change of the spatial position of the nasion
either in the vertical or anteroposterior direction
or both.
• The upward or downward rotation of the SN
plane.
• The upward or downward rotation of the Jaws.
• The change in the angle SN to the occlusal
plane.
• The degree of facial prognathism(18-20).
Due to the above mentioned factors affecting the
accuracy of ANB angle measurement, a number
of different, new measurements have been
developed to determine the actual sagittal skeletal
discrepancy.
To eliminate the influence of the anatomic
variations in nasion on the sagittal relationship of
the jaws, Jacobson 1975 presented the Wits
appraisal to obtain a measurement that was less
affected
by
variations
in
craniofacial
physiognomy. However there were difficulties
with this analysis as it was influenced by the
following factors:
• The occlusal plane was not easily reproducible,
especially in mixed dentition
cases where the teeth are not fully erupted.
• Patients with open bite, severe cant of occlusal
plane, multiple impactions,
missing teeth, skeletal asymmetry or steep curve
of spee.
• Any change in the angulation of the functional
occlusal plane caused by either
normal development of the dentition, or by
orthodontic intervention could profoundly
influence the Wits appraisal(1).
A popular recent alternative Beta angle avoids use
of functional plane and is not affected by jaw
rotations But it uses point A and point B, which
can be remodelled by orthodontic treatment and
growth(1).
Furthermore, as shown by various
studies, the reproducibility of the location of
condylion on mouth-closed lateral head films is
limited (8,9), Instead of condylion, centre of
condyle could be used, but approximation of
centre of condyle is difficult (1).
In the present study the mean value of BETA
angle in class I, II and III pattern as shown in
(table 2) were nearly the same result of Baik and
Ververidou, with a highly significant differences
among the three skeletal relation and a non
significant gender differences, table 4 showed that
BETA angle had a negative significant relation
with ANB in class III and with WITS in all
classes but a positive relation with YEN angle in
class III and with W angle in all skeletal classes.
Most recently introduced sagittal dysplasia
indicator by Neela et al. is YEN angle. But since
it measures an angle between line SM and MG,
rotation of jaw because of growth or orthodontic
treatment can mask true basal dysplasia(10), the
mean value of YEN angle of the present study is
nearly the same result of Neela et al., with a
highly significant differences among the three
skeletal relation (table 2,3) and a non significant
gender differences except in class II group (table
1).
To overcome some of the limitations of the
previously discussed parameters, the W angle was
developed. This measurement does not depend on
unstable landmarks or the functional occlusal
plane. It uses three stable points—point S, point
M, and point G (11). The mean value and standard
deviations of W angle of the three skeletal
relations had been shown in (Table 2) and this
results
is
similar
to
Wasundhara.etal.
Receiver operating characteristics curves showed
that a W angle between 51 and 56 degrees can be
considered to have a Class I skeletal pattern. With
an angle less than 51 degrees, patients are
considered to have a skeletal Class II relationship
and with an angle greater than 56 degrees, patients
have a skeletal Class III.
One way ANOVA followed by LSD showed that
there was a highly statistically significant
difference between the mean value of W angle of
the three groups (table 2,3).between gender,
according to independent sample t-test, there was
Vol. 24(2), 2012
no statistically significant difference between
male and female groups (table 1).
Table 4 showed that The W angle had a negative
significant relation with ANB in all three classes
and with WITS appraisal in class III group, while
it had a positive significant relation with BETA
and YEN angles in all the three skeletal relations.
The geometry of the W angle gives it the
advantage to remain relatively stable even when
the jaws are rotated or growing vertically. This is
a result of rotation of the S–G line along with jaw
rotation, which carries the perpendicular from
point M with it. Because the M–G line is also
rotating in the same direction, the W angle
remains relatively stable. Therefore, measurement
of W angle is useful sagittal parameter in skeletal
patterns with clockwise or counterclockwise
rotation of the jaws as well as during transitional
period when vertical facial growth is taking place
(figure 2) (11).
From this study we can conclude that:
1. The W angle is a diagnostic tool to evaluate
the AP jaw relationship more consistently.
2. The mean value for the W angle in Iraqi adults
with a Class I, II, and III skeletal relations
were 54.8, 49.6 and 59.83 respectively. .
3. There is statistically significant difference in
the mean value of W angle among the three
skeletal patterns.
4. There is no statistically significant difference
between mean W angle values of males and
females.
5. The W angle had a negative significant
relation with ANB in all three classes and with
WITS appraisal in class III group, while it had
a positive significant relation with BETA and
YEN angles in all the three skeletal relations.
Clinical importance
W angle adds a valuable tool for assessment of
AP jaw relationship. Along with other parameters,
it should enable better diagnosis and treatment
planning for patients.
REFERENCES
1. Baik C Y, Ververidou MA new approach of assessing
sagittal discrepancies: the Beta angle. Am J Orthod
2004; 126: 100–105.
2. Wylie WL. The assessment of anteroposterior
dysplasia. Angle Orthod 1947; 17: 97–109. (IVSL)
3. Riedel RA. A cephalometric roentgenographic study
of the relation of the maxilla and associated parts to
the cranial base in normal and malocclusion of the
teeth. Thesis, Northwestern University Dental School,
1948.
4. Jacobson A. The “Wits” appraisal of jaw disharmony.
Am J Orthod 1975; 67: 125–138.
5. Moyers R E, Bookstein F L, Guire K E. The concept
of pattern in craniofacial growth. Am J Orthod 1979;
76: 136–148.
6. Nanda R. Biomechanics and esthetic strategies in
clinical orthodontics. Elsevier, St. Louis 2005: pp. 38–
73.
7. Adenwalla S T, Kronman J H, Attarzadeh F. Porion
and condyle as cephalometric landmarks: an error
study. Am J Orthod, 1988; 94: 411–415
8. Moore R N, DuBois L M, Boice P A, Igel K A. The
accuracy of measuring condylion location. Am J
Orthod 1989; 95: 344–347.
9. Ghafari
J,
Baumrind
S,
Efstratiadis
SS.
Misinterpreting growth and treatment outcome from
serial cephalographs. Clin Orthod Res 1998; 1: 102–
106.
10. Neela P K, Mascarenhas R, Husain A. A new sagittal
dysplasia indicator: the yen angle. World J Orthod
2009;10: 147–151
11. Wasundhara A. Bhad , Subash Nayak, Umal H. Doshi.
A new approach of assessing sagittal dysplasia: the W
angle. Eur J Orthod 2011;
12. Rakosi T. An atlas and manual of cephalometric
radiography. 2nd ed. London: Wolfe medical
publications Ltd.; 1982. p. 7, 35, 40, 43, 45, 47-53, 61,
65, 85- 86, 135.
13. Downs WB. Variations in facial relationship: their
significance in treatment and prognosis. Am J Orthod
1948; 34(10): 812-40.
14. Nanda R S, Merrill R M. Cephalometric assessment of
sagittal relationship between maxilla and mandible.
Am J Orthod 1994; 105: 328–344
15. Braun S, Kittleson R, Kim K. The G-Axis: a growth
vector for the mandible. Angle Orthod 2004; 74: 328–
331. (IVSL)
16. Steiner CC. Cephalometrics for you and me. Am J
Orthod 1953; 39(10): 729-55.
17. Freeman RS.Adjusting A-N-B anglees to reflect the
effect of maxillary position. Angle Orthod 1971; 41;
332-5. (IVSL)
18. Chang
HP.
Assessment
of
anteroposterior
jawrelationship. Am J Orthod 1987; 92: 117- 22.
19. Walker Gf, Kowalski C. the distribution of the
ANBangle in “normal” individuals. Angle Orthod
1971; 41; 332-5.
20. Kammalamma. Evaluation and correlation of beta
angle and wits appraisal in various skeletal
malocclusion groups among patient visiting
government dental college,Bangalore.
A master
thesis.Department of orthodontist and dentofacial
orthopedics.Rajiv Gandi University of health science,
Bangalore, 2009.
Vol. 24(2), 2012
Table 1: Gender difference of the different methods in each of the three skeletal pattern using
independent sample t-test.
variable
Class I
Class II
Class III
ANB
WITS
BETA
W-angle
YEN-angle
ANB
WITS
BETA
W-angle
YEN-angle
ANB
WITS
BETA
W-angle
YEN-angle
Male
mean S.D
3.44 0.9
0.776 1.7
31.68 2.6
55.2 1.5
123.3 2.1
6.955 1.5
4.094 1.8
23.36 4.3
49.59 1.8
116.4 2.1
-0.1
1.6
-3.14 3.1
37.27 4.2
59.9 2.2
129.3 3.2
Female
mean S.D
3.069 0.9
-0.29 1.6
31.03 2.8
54.45 1.7
122.1 2.3
7.111 1.6
3.862 2.2
23.72 3.8
49.61 1.8
114.9 2.2
0.214 1.4
-3.35 2.3
37.32 4.2
59.75 2.6
128.7 3.3
Gender difference
T-test
sig
1.512
0.13
2.416
0.019
0.874
0.38
1.72
0.091
2.077
0.053
-.315
0.754
0.36
0.721
-.276
0.784
-.036
0.972
2.151
0.038
-.799
0.428
0.291
0.772
-.049
0.961
0.235
0.815
0.726
0.471
Table 2: Descriptive and comparative statistics among the three skelatal relations for the total
sample.
variables
ANB
Wits(mm)
BETA
W_angle
Yen_angle
class
Class I
Class II
classIII
Class I
Class II
classIII
Class I
Class II
classIII
Class I
Class II
classIII
Class I
Class II
classIII
N
54
40
58
54
40
58
54
40
58
54
40
58
54
40
58
Mean
3.24
7.02
0.05
0.20
3.99
-3.24
31.33
23.53
37.74
54.8
49.6
59.83
122.6
115.7
129
S.D
0.91
1.54
1.49
1.68
2.01
2.75
2.7
4.04
3.68
1.63
1.77
2.41
2.28
2.26
3.24
S.E
0.1
0.2
0.2
0.2
0.3
0.4
0.4
0.6
0.48
0.2
0.3
0.3
0.3
0.4
0.4
Min.
1
5
-4
-3.1
1.01
-12.3
26
13
34
51
44
56
117
112
123
Max.
5
10
3
3.8
9.75
1.3
35
28
49
57
51
66
125
118
136
F-test
Sig.
326.4
0.000
125.5
0.000
198.7
0.000
314.5
0.000
292.9
0.000
Table 3: Comparison between each two different skeletal pattern using LSD .
Variables
ANB
WITS
BETA
W-angle
YEN-angle
Class I-class II
Mean difference p-value
-3.78
0.000
-3.78
0.000
7.80
0.000
5.19
0.000
6.94
0.000
Class II- class III
6.97
0.000
7.22
0.000
-14.21
0.000
-10.22
0.000
-13.3
0.000
Class I-class III
3.18
0.000
3.44
0.000
-6.40
0.000
-5.03
0.000
-6.35
0.000
Vol. 24(2), 2012
Table 4: The correlation between the variables in class I,II and III skeletal relations.
Variables
ANB
Wits
BETA
W-angle
class
Class I
Class II
Class III
Class I
Class II
Class III
Class I
Class II
Class III
Class I
Class II
Class III
Yen
.020
-.522-**
-.580-**
.044
-.108-.217.154
.070
.302*
.733**
.579**
.788**
W- angle
-.339-*
-.391-*
-.680-**
-.098-.103-.441-**
.362**
.381*
.564**
BETA
-.125-.135-.644-**
-.301-*
-.512-**
-.822-**
Wit
.485**
.395*
.622**
**. Correlation is significant at the 0.01 level.
*. Correlation is significant at the 0.05 level.
Figure 1: The construction and mode of
measuring the W angle.
Figure 2: W angle remains relatively stable
even when jaws are rotated.
Vol. 24(2), 2012
A comparative study
A comparative study evaluating the microleakage of
different types of restorative materials used in restoration
of pulpotomized primary molars
Zainab A. Al-Dahan, B.D.S., M.Sc. (1)
Aseel I. Al- Attar, B.D.S., M.Sc. (2)
Huda E.A. Al-Rubaee, B.D.S., M.Sc. (2)
ABSTRACT
Background: Possibly the greatest deterrent to the development of an ideal restorative material is the leakage that
occurs along the restoration, tooth interface. There is yet no truly adhesive dental material that exactly duplicates
physical properties of the tooth structure. This in vitro study was carried out to compare the microleakage of two
types of restorative materials used in pediatric dentistry Colored light curing compomer(Twinky star) and nano
ceramic restorative material (Ceram.x)) with that of amalgam by measuring their ability to prevent dye penetration.
Materials and Methods: Standardized Proximo-occlusal cavity preparations were prepared in 30 extracted sound
primary first lower molars. Pulpotomy was performed, and pulpotomy paste filled the pulp chamber with hard setting
cement over it all have same occlusal depth. The teeth were then randomly divided into three groups: Group A:
filled with Amalgam. Group B: filled with compomer (Twinky star). Group C: filled with nano ceramic (Ceram.x).
After that the teeth were stored in distilled water for 30 days at 37 °C in an incubator and during the period of storage
the teeth were subjected to 300 thermal cycles (10 cycles each day), then sectioned to be examined under the
stereo microscope.
Results: Data was analyzed using ANOVA test with help of spss soft ware, even though nano ceramic (Ceram. X)
showed higher resistance to dye penetration, when compared to compomer (Twinky star and amalgam), there
were no significant differences between the three studied groups in their resistance to dye penetration.
Conclusion: Depending on the ability to prevent marginal leakage, nano ceramic (ceram.x) and compomer (Twinky
star) restorative materials can be used as an alternative to amalgam in restoring pulpotomized primary teeth.
Key words: Amalgam, Colored light curing compomer, Twinky star, Nano Ceram.x restorative material,
Microleakage. (J Bagh Coll Dentistry 2012;24(2):150-154).
INRODUCTION
Adherence of the restorative material to the cavity
walls is one of the most important characteristics
for it to be proven as an ideal material because it
prevents microleakage(1). Microleakage is defined
as the chemically undetectable passage of
bacteria, fluids, molecules or ions between the
cavity walls and restorative materials. This
seepage can cause hypersensitivity of restored
tooth, tooth discoloration, recurrent caries, pulpal
injury and accelerated deterioration of the
restorative material (2) . One of the most important
problems today of the restorative dentistry is the
failure of restorative material to obtain a complete
bond with the enamel and dentin, the formation of
microfissures, the penetration of ions, molecules,
bacteria and fluids into these fissures and the
occurrence of postoperative pain, discoloration at
the cavity edges, secondary decays and pulpal
inflammations. It has been reported that this
phenomenon, referred to as the microleakage, is
due to the inadequacy of marginal adaptation
between the restoration material and cavity wall.
(1) Professor. Department of Pedodontics and Preventive
Dentistry. College of Dentistry. Baghdad University.
(2) Assistant lecturer. Department of Orthodontics, Pedodontics
and Preventive Dentistry. College of Dentistry. Al-Mustansiria
University.
The microleakage is determined today by many in
vivo and in vitro techniques such as; staining,
which, is the most preferred one(3). Many changes
have occurred in development and availability of
restorative materials for children. The amalgam
has been used for more than 150 years as a
restorative material due to its satisfactory clinical
characteristics: Low sensitive technique (moisture
contamination), satisfactory longevity on primary
teeth and diminished microleakage related to
corrosive products in tooth/restoration interface.
In addition, amalgam is inexpensive and easy to
handle (4).
Compomers contain glass ionomer cement
combined with visible light polymerized resin
component. Their excellent physical properties
along with fluoride releasing ability, minimal
steps in placement and composite like esthetics
make them the strongest and most esthetically
desirable material. Most restorative materials
show varying degrees of marginal leakage
because of dimensional changes and lack of
adaptability to cavity walls. Microleakage
investigation
of
compomers
and
their
comparison with other materials have compared
only a limited number of products but in general
have shown adequately sealed restoration
margins(5).
Vol. 24(2), 2012
Since nanotechnology was introduced to dentistry,
nano composites with filler sizes ranging from
0.01 to 0.04 mm have been developed. Nan
composites have many advantages, such as
reduced polymerization shrinkage, increased
mechanical
properties,
improved
optical
characteristics and better gloss retention(6) .
Ceram·X (Dentsply DeTrey, Konstanz, Germany),
was developed after introduction of the
nanotechnology in dentistry, it's a light cured,
radiopaque restorative material for restoration of
anterior and posterior teeth. It combines
Nanotechnology, with improved organically
modified Ceramic particles (7).
Nano ceramic (Ceram·X) contains glass fillers
(1.1–1.5 μm) but differs from conventional hybrid
composites by two important features:
methacrylate-modified silicon dioxide containing
nano-filler (10 nm) substitute the microfiller that
is typically used in hybrid composites
(agglomerates of silicon dioxide particles).
According to the manufacturer’s data, filler
concentration is 76% by weight and 57% by
volume (6,7).
Microleakage performance may be useful for
comparative assessment of materials and selection
of restorative materials with adequate marginal
seal is directly related to the success and longevity
of the restorations (2).
This study designed to assess the microleakage of
different restorative materials:
1. Amalgam.
2. Compomer (Twinky star).
3. Nano ceramic (Ceram.x).
Used in restoration of pulpotomized primary
molars
Thirty sound human primary lower first molar
teeth free of dental caries extracted for
orthodontic purpose (serial extraction) were
collected. After extraction; the teeth were cleaned
with rubber cup and pumice and scaled by ultrasonic scalar to remove any calculus on the
surfaces of the teeth. The teeth stored in distilled
water containing thymol crystal 1%, at room
temperature (8).
The teeth were examined for cracks by the use of
magnifying eye lens. Any tooth associated with
cracks was excluded and only sound teeth were
used (9).
Standardized class-II mesio-occlusal cavity was
prepared. A tungsten carbide fissure bur No.330
in a turbine hand piece was used with proper
water cooling to prepare the cavities (10).
The buccolingual width of occlusal preparation
was (2.5mm) just enough to allow the entrance of
A comparative study
no. 6 round bur while the depth of occlusal
preparation was (6mm) (measured from pulpal
floor to cuspal tip).The buccolingual width of
proximal box was( 4mm) and the gingival seat
was located (2mm )coronal to CEJ . The length of
proximal buccal and lingual walls was (4mm)
(measured from gingival seat to cuspal tip (11).
Pulpotomy procedure was done for all teeth and
floor of pulp filled with pulpotomy paste that is a
mixture of one drop of euginol with one drop of
tricresol formalin mixed with zinc oxide euginol
powder then hard setting cement base of zinc
phosphate cement was applied over it, and the
occlusal depth of cavity calibrated by reamer with
stopper to be the same depth from cusp tips to the
cement base for all the teeth about 1.5mm (12).
The teeth were divided into three groups of ten
teeth each:
• Group A: was restored with amalgam.
• Group B: was restored with compomer
(Twinky star).
• Group C: was restored with nano ceramic
(Ceram.X).
The teeth were then stored in incubator for 30
days in distilled water at 37°C each day the teeth
were subjected to 10 thermal cycles (300 cycles).
This procedure was done to simulate temperature
changes in the oral environment which might
result in changes in the microspace around the
restoration (13). Each tooth was placed in block
of cold cure acrylic resin to seal the root apex and
furcation area to the area 1mm below the cement
enamel junction, then the crown with the block
was sealed with two layers of nail varnish to
within approximately 1mm of the restoration
margins to prevent dye penetration in areas other
than the exposed margins (14-17). All the teeth were
immersed in 2% methylene blue dye solution at
37°C in an incubator for 24 hours (1, 3, 10). Then
all the teeth were removed from the dye and
washed under running water.
Each tooth was then sectioned into two halves and
two samples were prepared from each half by
sectioning through the center of each restoration,
this provide two occlusal and two gingival
margins
allowing
for
identification
of
microleakage through dye penetration. The degree
of microleakage was determined by the degree of
dye penetration from the margins of the
restoration towards the pulp chamber by viewing
under a binocular stereo microscope with 10-20 X
magnification (1).
Under a stereomicroscope the teeth were studied
to measure the depth of dye penetration at the two
surfaces of the cavity and the score which was
higher was given as score to the particular tooth.
All the scoring was carried out by a single person
Vol. 24(2), 2012
and as seen clinically in figures (2), (3), (4), (5)
and scoring criteria used for the study was as
follows (9):
0 = No dye penetration
1 = Dye penetration between the restoration and
the tooth into enamel only.
the tooth in the enamel and dentin.
the tooth into the pulp chamber.
ANOVA test was used to find any statistical
significant differences among the three studied
groups.
RESULTS
Table (1) shows the descriptive statistics for the
result of methylene blue dye penetration score for
the three materials used in present study, this table
shows that the higher mean score of dye
penetration was for compomer (Twinky star)
(1.80±0.92) followed by amalgam (1.70±1.16)
and the lower mean was found for nano ceramic
(Ceram.x) (1.20±1.03). ANOVA test showed no
significant difference among the three groups (F=
0.952 P= 0.398).
The percentage of each score is shown in table
(2), this table shows that percentage of teeth with
absence of dye penetration (score 0) was higher
among nano ceramic (Ceram. x) (30%) than both
amalgam (20%) and compomer (Twinky star)
(10%). On the other hand, concerning maximum
score of dye penetration (score 3) the higher
percentage of teeth was found for amalgam (30%)
followed by compomer (Twinky star) (20%) and
lower percentage was found for nano ceramic
(Ceram.x) (10%).
Figure (1) shows that the percentage of dye
penetration score (score2) was higher for teeth
filled with compomer (Twinky star) (50%) than
both amalgam and nano ceramic (Ceram.x)
(30%).
DISCUSSION
Dye penetration is used as a measure to evaluate
the performance of the restorative materials. This
in vitro study was carried out to evaluate and
compare the micro leakage of two new materials
in the market and compare them with amalgam (9).
The standardized design of a class II cavity
preparation and pulpotomy procedure for the
sound primary molars used in this study are more
commonly representing the main percentages of
restorations done for children because most of
patient come with severe pain because of pulpal
involvement and most of them come with
proximal lesions so cavity preparation in proximal
boxes extended to the enamel 2mm above
A comparative study
cementoenamel junction for standardizations for
the three restoratives materials to be the same to
support the validity of the study design(9,18).
Thermal cycling is commonly employed in dye
penetration test of dental materials. The regimen
of thermal cycling was included in this study
because it was commonly used in other previous
studies (1, 10, 19). The upper temperature (55°C) may
be encountered in vivo, but it was perceived that
higher temperature is relatively hot and may cause
discomfort and this two border of temperature
(4°C and 55°C) simulating changes in temperature
in oral cavity (in vivo) and also samples are
thermocycled through 30 days as aging process to
see effect of time on the restoration (5,20).
Many studies had been done on microleakage of
class II of posterior permanent teeth restorations
and the findings obtained had been assumed to
apply to primary teeth, but some evidences
suggest significant chemical and morphological
differences between primary and permenant
dentition This may be of fundamental importance
because of morphological differences such as a
larger tubular diameter and less mineralization of
intertubular dentin areas (21,22).
Furthermore,
information
regarding
microleakage
in
restorations of pulpotomised primary human
molars are limited, for these reasons this study
was done to estimate microleakage of different
restorative materials in pulpotomized primary
human molars.
The result demonstrates that none of the three
filling material was free from dye penetration.
Even though, nano ceramic (Ceram.x) showed the
least dye penetration with a mean score of
(1.20±1.03), while compomer(Twinky star)
demonstrated the greatest dye penetration with
mean score of(1.80± 0.92), but there were no
significant differences between the three studied
groups.
The result data indicated no significant
differences between
amalgam group and
Compomer(Twinky star) group, this results in
agreement with Kitty et al(23), and Mass et al(22)
who compared
compomer with amalgam
restorations in primary teeth, they led to the
conclusion that compomer may be recommended
as alternative to amalgam in primary molars. Also
the results agree with Marks et al(24) who reported
a 94% success rate for compomer after 3 years,
which is an annual failure rate of 2% and
comparable to success rates in permanent teeth.
The amalgam used achieved 88% success during
the same period. Previous studies have also failed
to find significant differences between amalgam
and compomers in relation to restoration failures
Vol. 24(2), 2012
despite low failure rates, marginal integrity seems
to be different.
The findings of this study showed no significant
difference between amalgam group and nano
ceramic(Ceram.X ) group, this come in agreement
with the
results of Marcio et al(1)
who
demonstrate that bonding agents and resin-based
materials can exhibit excellent marginal seal for
restoration of pulpotomized primary molar when
compared with the amalgam. El-Kalla et al (11)
demonstrated that bonded resin-based materials
increased the fracture resistance of primary teeth
restored after pulpotomies. .
Comparison between compomer(Twinky star)
group and nano ceramic(Ceram.X) group, also
indicated no significant difference, this may be
due to the fact that both materials have a higher
bond strength to enamel and dentin, better
mechanical properties , higher filler content and
resistance to occlusal load and low polymerization
shrinkage (6,7,25).
From this in vitro study results, compomer
(Twinky star) and nano ceramic (Ceram.X) show
no significance difference of dye penetration and
resistance to marginal leakage compared with
amalgam and can be recommended as a good
alternative to amalgam for restoring primary teeth
in children.
REFERENCES
1. Marcio G, Kelsey L. Bookmyer, Patricia V, Franklin
GG. Microleakage of Restorative Techniques for
Pulpotomized Primary Molars J Dent Child 2004; 71:
209-211.
2. Yazici AR, Baseren M, Dayangac B. The effect of
current-generation bonding systems on microleakage
of resin composite restorations. Quintessence Int 2002;
33:763-769.
3. Yavuz, Izzet, Aydin H. New method for measurement
of surface areas of microleakage at the primary teeth
by biomolecule characteristics of methilene
blue.Biotechnology and Biotechnological Equipment
2005; 19(1):181-187.
4. Cristiane M, Luciana ML. Restorative Treatment on
Class I and II Restorations in Primary Molars A
Survey of Brazilian Dental Schools. J Clin Pediatr
Dent 2005 ; 30(2):175-178.
5. Mali P, Deshpande S, Singh A. Microleakage of
restorative materials: An in vitro study. J Indian Soc
Pedod Prev Dent 2006; 7 (24):15-18.
6. Schirrmeister JF, Huber K, Hellwig E, Hahan P. Twoyear evalution of a newe nano ceramic restorative
material. Clin Oral Investig 2006; 10: 181-186.
7. Manuja N, Pandit IK, Srivastava N, Gugnani N,
Nagpal R. Comparative evaluation of shear bond
strength of various esthetic restorative materials to
dentin. 2011; 29(1): 7-13.
8. Gwinnett AJ, Garcia-Godoy F. Effect of etching time
and acid concentration on resin shear bond strength to
primary tooth enamel. Am J Dent 1995; 5:237-239.
A comparative study
9. Praphakar A Ra, Madan Mb, Raju O. The marginal
seal of a flowable Composite, an injectable resin
modified Glass lonomer and a Compomer in primary
molars - An in vitro study , J of Ind soci of Pedo and
Prev Dent 2003; 21(2):45-48.
10. Cleide CR. Martinohoni, Ricardo, Sousa V. Marginal
leakage of polyacid modified composite resin
restorations in primary molars. An invitro study.J Appl
Oral Sci 2005; 13(2):175-178.
11. El-Kalla IH, García-Godoy F. Fracture strength of
adhesively restored pulpotomized primary molars. J
Dent Child 1999; 66: 238-242.
12. Damle SG.. Text book of pediatric dentistry 2nd edition
Darya Ganj, New Delhi; 2004. ch.30 p.295, ch.29
p.279-280.
13. Cavalcante LMA, Pens AR, Amaral CM, Ambrosano
GMB, LAF. Influence of polymerization technique on
microleakage and microhardness of resin composite
restorations. Oper Dent 2003; 28(2): 200-206.
14. Malmstrom H, Schlueter M, Roach T, Moss ME.
Effect of thickness of flowable resins on marginal
leakage in class II composite restorations. Oper Dent
2002; 27: 373-380.
15. Mgeed M. The effect of adhesive system on marginal
leakage of Cl II compound amalgam-composite resin
restoration(in vitro study).A Master Thesis.
Department of Conservative Dentistry. College of
Dentistry.University of Bghdad. 2001.
16. Al-Zubidi M. Assessment of microleakage of different
tooth-colored restorative materiasl in primary teeth.(in
vitro study).A Master Thesis. Department of Pediatric
Dentistry. College of Dentistry .University of Bghdad.
2004.
17. Najman H. Assessment of Microleakage of Different
Restorative Materials in Pulpotomized Primary Molars
(An in vitro study). A Master Thesis. Department of
Pediatric
Dentistry.
College
of
Dentistry
Medical.University of Hawler. 2008.
18. Ben-Amar A, Liberman R, Nordenberg D, Metzger Z.
The effect of retention grooves on gingival marginal
leakage in Cl-II posterior composite resin restorations
Oral Rehabil 1988; 119: 725-728.
19. Majeed M. The effect of adhesive system on marginal
leakage of class II compound amalgam-composite
resin restorations (In vitro study). A Master Thesis,
Department of Conservative Dentistry, College of
Dentistry, University of Baghdad 2001.
20. Yap AUJ and Wee KEC. Effect of cyclic temperature
changes on water sorption and solubility of composite
restoratives. Oper Dent 2002; 27: 147-153.
21. Sumikawa DA, Marshall GW, Gee L, Marshall SJ.
Microstructure of primary tooth dentin. Pediatric Dent
1999; 21: 439-444.
22. Norbert K, Roland D, Frankenberger E. Compomers
in restorative therapy of children: a literature review
International Journal of Paediatric Dentistry 2007; 17
(1): 2-9.
23. Kitty MH, Stephen HYW. Clinical evaluation of
compomer in primary teeth 1-year results JADA1997;
8: 128.
24. Marks LA, Weerheijm KL, Amerongen WE. Dyract
versus Tytin Class II restorations in primary molars:
36 months evaluation. Caries Res 1999; 33: 387-392.
25. Mass E, Gordon M, Fuks AB. Assessment of
compomer proximal restorations in primary molars: a
retrospective study in children. J Dent Child 1999; 66:
93-97.
Vol. 24(2), 2012
A comparative study
Table 1: Dye penetration score (Mean±SD) for the three studied groups
Groups
Amalgam
Twinky Star
Ceram.X
Mean
1.7
1.8
1.2
±SD
1.16
0.92
1.03
F
d.f
Sig
0.952
2
0.398
Table 2: Percentage for score of dye penetration of the three studied groups
Groups
Scores
0
1
2
3
Amalgam
No. %
2
20
2
20
3
30
3
30
Twinky Star
No.
%
1
10
2
20
5
50
2
20
Ceram.X
No. %
3
30
3
30
3
30
1
10
Figure 1: Comparison of dye penetration among the three studied groups
Figure 2: Digital photograph by
stereomicroscope showing score-0 dye
penetration (Amalgam)
penetration (Compomer (Twinky star) group)
penetration (Nano ceramic (Ceram.X))
penetration (Compomer (Twinky star) group)
Vol. 24(2), 2012
Oral health status among
Oral health status among a group of pregnancy and
lactating women in relation to salivary constituents and
physical properties (A comparative study)
Zinah M. Taqi Issa, B.D.S. (1)
Sulafa K.El-Samarrai, B.D.S., M.Sc., Ph.D. (2)
ABSTRACT
Background: The physiological and hormonal changes during lactating and pregnancy may affect dental and
gingival health conditions. The aims of this study were to investigate the occurrence and severity of both dental
caries and periodontal diseases among these women in relation to different salivary variables and constituents
Materials and Methods: A study group representing 30 lactating mothers whose infants were 4-6 months of age, and
30 pregnant women in the third trimester of pregnancy. Their age was 20-21 years. The control group comprised 30
married non-pregnant nulliparous women. Diagnosis and were recording of dental caries according to the WHO
(1987)criteria and GI, PlI according to the Löe and Sillness (1964), CI according to the Ramfjord, probing pocket
depth according to the Carranza et al, 2002. Stimulated salivary sample was collected according to the Tenovuo
&Lagerlof. The average salivary flow rate was measured from total volume, and the pH was determined using the pH
meter. Salivary samples were chemically analyzed for the detection of electrolytes (Ca and PO4), and
immunoglobulin (IgA), in addition to lysozyme enzyme.
Results: The total mean value of dental caries were recorded to be the highest among pregnant group followed by
lactating then control with statistically no significant difference (P> 0.05). Concerning the plaque index, gingival
index and calculus indices, they were recorded to be highest among pregnant group followed by lactating then
control with statistically no significant difference (P> 0.05). Regarding to pH, the control group showed the highest
value while the pregnant group exhibited the lower one with highly significant differences was recording between
groups P=0.000. The flow rate showed no significant difference between groups. No clinical loss of attachment was
seen between the groups. Calcium ions showed a high concentration in saliva of the lactating group compared to
the other two groups with highly significant differences P=0.01. Phosphorous ions showed a high concentration in
saliva of the lactating group compared to the other two groups with statistically no significant difference (P> 0.05).
Regarding salivary lysozyme the highest value was recorded among the pregnant group, while the lowest value was
recorded in the control with statistically no significant difference (P >0.05). The same result was seen for salivary IgA
but with a statistically significant difference (P <0.05).
Conclusion: The severity of dental caries and gingival inflammation were the highest among pregnant group
compared to the other two groups. This may related to the changes in the salivary pH and constituent during
pregnancy.
Keywords: lactating, pregnancy, dental caries, oral health status, salivary pH, salivary flow rate, salivary buffer,
calcium, phosphorous, lysozyme enzyme, IgA. (J Bagh Coll Dentistry 2012;24(2):155-159).
INTRODUCTION
Pregnancy and lactation are physiological statuses
considered to modify metabolism in animals (1).
Both require that numerous physiological
adaptations must be made by the maternal
organism, to ensure that all the needs of the
growing fetus are met and that her own vital
functions are maintained (2). Changes occurring
during pregnancy in women are well documented
but less is known about lactation (3). These
changes were reported to have an impact on oral
heath as well as dental health. Studies reported an
increase in gingival inflammation and caries –
experience during pregnancy (4-12). Hormonal and
physiological changes continue during lactation,
however there are limited studies investigating
dental and gingival health status among lactating
women.
(1) MSc student department of pediatric and preventive
dentistry, college of dentistry, University of Baghdad.
(2) Professor, department of pediatric and preventive dentistry,
college of dentistry, University of Baghdad.
Other studies were conducted investigating
changes in salivary variables (flow rate, pH and
buffer capacity) as well as salivary constituents as
electrolytes, immunoglobulin and hormonal
changes during pregnancy. These were correlated
with oral and dental health, and a controversy in
the result was noticed (4, 11, 13-15). On other hand
only one Iraqi study was able to be found
regarding salivary calcium during lactation (16).
The aim of this study was to investigate oral
health status in relating to salivary variables and
constituents among lactating and pregnant groups.
MATERIALS AND MATHODS
The sample taken in this study was 90 women
divided into three groups; each group is composed
of 30 volunteers; a first study group representing
lactating mothers whose infants were 4-6 months
of age and the second group was pregnant women
in the third trimester of pregnancy. Each of them
were 20-21 years old primiparous mothers. The
Vol. 24(2), 2012
supernatant was separated by micropipette and
was divided into three portions, stored at (-20°C)
in a deep freeze till being assessed in the Teaching
Laboratories of the Medical City Hospital.
Data process and analysis were done by using
the Statistical Package for Social Sciences (SPSS
version 17). Statistical tested used in this study
were; analysis of variance (ANOVA), least
significant difference (LSD) test, were used to test
the difference between variable, Paerson‫ۥ‬s
correlation coefficient were all applied to see if
there is any correlation between variables. The
confidence limit was accepted at 95% (P < 0.05).
control group comprised 30 married non-pregnant
nulliparous women; these women were age
matched with the study group. Subjects should be
without any medical disease and no history of
smoking. Dental examination was done after
collection of salivary sample. The examination of
dental caries was conducted according to the
criteria of WHO(17). Oral examination was carried
out using plane mouth mirror and dental explorer.
The collection of stimulated salivary samples was
performed following assesment of dental plaque
under standard condition following instruction
cited by (18). Each individual was asked to chew a
piece of Arabic gum (0.5-0.7 gm) for one minute
all saliva was removed by expectoration, chewing
was then continued for five minutes with the same
piece of gum and saliva collected in a sterile
screw capped bottle. Salivary pH was measured
using an electronic pH meter and flow rate of
saliva was expressed as milliliter per minute (ml /
min). The salivary samples were then taken to the
laboratory for biochemical analysis. Samples were
centrifuged at 4000 rpm for 30 minutes; the clear
RESULTS
Table 1 demonstrates the mean values and
standard deviations of caries- experience
according to DMFS/DMFT indices among study
and control groups. Results showed that there no
statistically significant differences between three
groups.
Table 1: Caries – Experience (Mean and Standard Deviation) among Study and Control Groups.
Groups
Lactating
Pregnant
Control
DS
Mean±SD
1.33±2.83
1.83±3.04
1.10±2.95
MS
Mean±SD
1.37±4.25
1.60±3.96
0.83±1.89
FS
Mean±SD
0.53±0.99
0.80±1.44
0.27±0.63
Table 2 reveals the mean values of plaque,
calculus and gingival indices among study and
control groups. For the three indices statistically
no significant differences were recoreding
between the three groups (P >0.05).
The correlations coefficients between plaque
and calculus indices with the gingival index
among the three groups showed a positive
statistically significant correlation between plaque
index and gingival index in the control and
lactating groups (r = 0.456, P <0.05). No
correlation was seen between gingival index and
plaque index in the group of pregnancy. Results
also showed that gingival index is not correlated
with calculus index in all groups.
Table 3 presents pH values, rates of secretions
of stimulated saliva and buffer capacity among
study and control groups. Concerning pH, the
control group showed the highest value while the
pregnant group exhibited the lower one; a
statistically significant difference was noticed
between the three groups. When the least
significant differences test was applied the
statistically highly significant differences were
present in pH value between the pregnant group
with the control, and the lactating group with
DMFS
Mean±SD
3.23±6.19
4.23±5.94
2.20±3.71
DMFT
Mean±SD
1.060±2.12
1.70±2.10
0.996±1.35
control. Salivary flow rate mean value was the
highest in the pregnant group compared to other
groups, statistically no significant difference was
noticed between the three groups (P >0.05).
Regarding the buffer capacity, results showed a
highest value among the control group with
statistically highly significant differences between
them.
In general no significant correlations were
recorded between caries-experience with salivary
variables among the three groups, except for the
salivary flow rate; a negative significant
correlation with DMFS in group of lactating
women was noticed (r=-0.384 P=0.036). Also no
significant correlations were recorded between
plaque and gingival indices in addition to calculus
index with salivary variables among the three
groups, except for the salivary pH; a positive
significant correlation was seen with gingival
index (r=0.363, P= 0.048) and a negative
significant correlation was seen in flow rate with
calculus index in the lactating group (r=-0.459, P=
0.011).
Table 4 shows the mean concentration values
of
salivary
electrolytes
(calcium
and
phosphorous), salivary lysozyme and IgA and
Vol. 24(2), 2012
statistically not significant (F=0.355, P=0.702).
Regarding salivary lysozyme the highest value
was recorded among the pregnant group, while
the lowest value was recorded in the control with
statistically no significant difference (P >0.05).
The same result was seen for salivary IgA but
with a statistically significant difference (P
<0.05).
standard deviation among different groups.
Calcium ions showed a high concentration in
saliva of the lactating group compared to the other
two groups, difference between the study and
control groups was statistically highly significant
(F=80.080, P=0.01) . Phosphorous ions showed
the highest concentration in saliva of the lactating
group compared to the other two groups,
difference between the three groups was
Table 2: Plaque Index, Gingival Index, and Calculus Index (Mean and Standard Deviation)
among Study and Control Groups
Groups
Lactating
Pregnant
Control
PlI
Mean±SD
1.230± 0.28
1.135± 0.29
1.195± 0.37
GI
Mean±SD
1.276± 0.28
1.340± 0.31
1.252± 0.31
CI
Mean±SD
0.009± 0.02
0.020± 0.06
0.003± 0.01
Table 3: Salivary (pH), Flow Rate and Buffer effect (Mean and Standard Deviation) among
study and control groups.
Groups
Lactating
Pregnant
Control
pH
Mean±SD
7.252* ± 0.363
7.000 ± 0.358
7.420 ± 0.304
Flow rate ml/min
Mean±SD
0.993±0.321
1.230±1.003
0.900± 0.303
Buffer capacity
Mean±SD
5.163**± 0.961
4.315± 0.452
6.835± 3.073
Table 4: Salivary Electrolytes (Calcium & Phosphorous), salivary lysozyme and IgA (Mean and
Standard Deviation) among Study and Control Groups.
Group
Lactating
Pregnant
Control
Statistical test
Ca ion mg/dl
PO4 mg/dl
Salivary Lysozyme (ng/ml)
Salivary IgA (mg/dl)
Mean ± SD
7.078±3.484
1.132±0.085
1.652± 0.202
F=80.08
P=0.000
Mean ± SD
6.043±3.321
5.512±2.388
6.019±2.485
F=0.355
P=0.702
Mean ± SD
27.30±18.093
29.86±23.431
26.54±16.155
F=0.239
P=0.788
Mean ± SD
25.75±7.935
36.22±22.721
25.29±1.002
F= 5.925
P=0.004
DISCUSSION
Although statistically not significant the highest
value of the DMFS was recorded among pregnant
women followed by lactating then the control.
This finding is not difficult to explain, pregnancy
is associated with many psychological and
stressful events that in turn lead to more self
neglect and change of dietary habits, as the
pregnancy itself is accompanied by an increase in
appetite with frequent snacking on candy or other
caries promoting foods (19). The elevation in the
severity of dental caries seen by the present study
among pregnant, may be related to changes in the
salivary physical properties involving the flow
rate, as well as, the buffering capacity and pH.
The lowest value of buffer capacity and pH were
recorded among pregnant group, this may
responsible to high caries experience. The
increase in salivary calcium concentration in
lactating women may be attributed to the
temporary demineralization of the maternal
skeleton that appears to be the main mechanism
by which lactating women meet these calcium
requirements (20). On the other hand a decrease in
the salivary calcium concentration in pregnant
group was seen which may be related to hormonal
fluctuation (21). Progesterone relaxes the smooth
muscle cells of uterus and other organ such as
gastrointestinal tract, resulting in slowing of the
gastrointestinal tract during pregnancy and
increases the absorption of several nutrients, most
notably iron and calcium. The same explanation
of calcium concentration reduction in pregnant
women could be applied for phosphorus as
phosphorus absorption goes side by side with
calcium in the gastrointestinal tract (22).
Vol. 24(2), 2012
The soft and hard tissues of the oral cavity are
under the protection of both non-specific and
specific immune systems. Their function is to
limit the microbial colonization of oral surfaces
and to prevent the penetration of noxious
substances through the surfaces and ensuing
damage to the underlying tissues (23). In this study
salivary IgA was the highest in the pregnant group
and the lowest in the control group with a
statistically
highly
significant
difference.
Secretion and synthesis of IgA may be affected by
stress, physical exercises, medications, menstrual
cycle, and pregnancy (24). The hormonal changes
during pregnancy may have altered the IgA levels
because the production of estrogen and
progesterone increases gradually until the eighth
month of pregnancy and both hormones modulate
the immune system during the gestational period
(15)
. The higher levels of salivary IgA may provide
greater protection against infections due to
gingival
inflammation
during
pregnancy.
Lysozyme co-operates with other antibacterial
systems (e.g. IgA) and causes bacteria
aggregation (25). Salivary pH and buffering
capacity reach their lowest values during the third
trimester of pregnancy, thus increasing the risk of
caries, which is further increased by enhanced
levels of salivary streptococcus mutans therefore
this increase may lead to increase in lysozyme.
On the other hand, elevated lysozyme content can
increase the clearance of bacteria from oral cavity,
thus playing a protective role. In addition the
increase in salivary lysozyme may be due to the
increased salivary flow rate during pregnancy (26).
The present study reported a positive
correlation between plaque and gingival indices
which was significant in the lactating and control
groups, but not in the pregnant group, thus, dental
plaque may not be the only etiological factor for
gingivitis among pregnant group compared to the
other two groups. During pregnancy, the action of
the hormones on the periodontal cells involves
altering the effectiveness of the epithelial barrier
to bacterial insult, and affecting the collagen
maintenance and repair increasing the risk of
gingival inflammation (28). Results revealed that
all women examined had gingival pocket not
higher than 3mm, and no clinical loss of
attachment. Periodontitis requires a chronic
inflammatory state of the gingiva lasting longer
than those months of pregnancy (15). Results
revealed that the changes in salivary variables and
composition may have an impact on the dental
and gingival health status of both the pregnant and
lactating groups. Thus, it is recommended that
these two groups to receive a special program to
control and prevent dental caries as well as
periodontal diseases.
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