contents - Факултет по Дентална Медицина към Медицински
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contents - Факултет по Дентална Медицина към Медицински
2 2 CONTENTS SCIENTIFIC ARTICLES Periodontology Effectiveness of nonsurgical periodontal therapy in conjunction with IL-1B polymorphisms A. Mlachkova, Chr. Popova 3 Conservative Dentistry A comparative study on the use of posts from dental practitioners and students E. Boteva 9 Comparison of the root canal obturation methods in the preclinical endodontics E. Boteva 13 Paediatric Dentistry Children`s oral diseases in Rouse region – Epidemiological research, a part of the National Program of Prophylaxis of oral diseases in children at the age of 0 – 18 M. Rashkova, L. Ribagin, Ts. Doganova, V.Alexieva 17 Parental role in relationship dentist - child M. Georgieva, M. Peneva 29 Influence of the etching time on dentin bond strength of primary teeth – in vitro study N. Gateva, R. Kabaktchieva 35 Prosthetic Dentistry Chewing simulator“Sofia”– construction, working principle and possible application of the device. Part I I. Ivanov, I. Chakalov 43 Construction of the chewing simulator“Sofia”– Basic modules, principle of functioning and possible applications. part II. I. Ivanov, I. Chakalov Orthodontics Epidemiological study of dental status and permanent canine erupt in children and adolescents aged 7 to 18 years H. Arnautska, V. Krumova 48 52 Public Dental Health Demographic processes and structure of the dental practices as prerequisites for market development of the dental services in Bulgaria K. Tzokov, L. Katrova 58 Review Children with special healthe care needs and prevention of oral diseases in the population L. Doichinova 63 Treatment of oral lesions in HIV and AIDS A. Krasteva, Vl. Panov 74 3 Periodontology Effectiveness of non-surgical periodontal treatment of chronic periodontitis in conjunction with IL-1B gene polymorphism Chr. Popova 1, A.Mlachkova2 Summary Background: The accepted in last two decades paradigm for the pathogenesis of periodontal diseases includes increased knowledge about effects of genetic factors in the initiation and progression of periodontitis. It is suggested that IL-1B-single nucleotide gene polymorphism (different alleles of cytokine genes) influence on susceptibility to periodontitis, on the progression of periodontal disease and on variations in clinical expression and outcome to therapy. Aim: The aim in this study was the identification of IL-1B genotype in patients with moderate and severe chronic periodontitis and treatment evaluation in conjunction with IL-1B gene polymorphisms and IL-1β expression. Material and methods: The patients with chronic periodontitis were divided in two groups according to treatment and were tested for IL-1B gene polymorphism in gingival tissue samples by single nucleotide polymorphism (SNP) PCR. Analysis of the IL-1β gene expression deviations was performed in the same patients by PCR. Results: The results of this study show that patients having IL-1B C [3953 / 4] T and IL-1B T [-511] C polymorphism demonstrate higher therapeutic efficiency with additional anti-inflammatory (Aulin®) compared to conventional non-surgical treatment. Conclusion: The presence of gene polymorphisms of IL-1B can determine susceptibility to periodontitis and additional modulating therapy is more appropriate. Key words: chronic periodontitis, IL-1B gene polymorphisms, single nucleotide polymorphisms, antiinflammatory therapy, IL-1β gene expression. 1 2 Assoc.Professor, PhD, Head of Dept of Periodontology, Medical University, Faculty of Dental Medicine, Sofia Assist.Professor, Dept of Periodontology, Medical University, Faculty of Dental Medicine, Sofia 4 When discussing the clinical decisions in the treatment plan for chronic periodontitis consideration of the role of IL-1 genotype of the patient is not recognized - for now there are no serious grounds to believe that genotype-positive patients should be treated differently from those who are genotypenegative for IL-1 gene polymorphism (8, 24, 25, 26, 27). The accepted concept for the influence of genotype on periodontitis requires the establishment of new therapeutic strategies that are focused on controlling genetic factors associated with mechanisms of bone destruction and loss of attachment (11, 12, 18, 21, 22, 28, 30). The use of additional anti-inflammatory agents in the conventional antimicrobial therapy of chronic periodontitis may modulate the response of the tissues so as to reduce loss of bone and connective tissue attachment in the presence of genetic susceptibility associated with gene polymorphism (9, 10, 20, 23, 31). The development of an integrated approach to the introduction of pharmacotherapy to target the body's response is expected to lead to the establishment of more effective and predictable periodontal therapy and long term successful control of periodontitis. Contemporary host modulation periodontal therapy (Host modulatory therapy) is justified precisely by the concept that it is possible to reduce tissue destruction and to achieve periodontal stability by inhibition of periodontal destructive aspects and / or stimulation of protective and regenerative components of the host response (13,14,15,17,23,28,30,33). There are clinical studies showing effectiveness of the administration of various non-steroidal anti-inflammatory drugs (NSAIDs) in the treatment of inflammatory periodontal disease (1,2,3,4,6,7,16,31,32), but no definite answer in the literature regarding the effectiveness of such adjunctive therapy in patients with chronic periodontitis and predetermined susceptibility to destructive response-related gene polymorphisms and increased production of proinflammatory cytokines (IL-1). Literature data suggests that additional antiinflammatory agents tend to show higher effectiveness of treatment as measured by reduction in the levels of pro-inflammatory cytokines and clinically by a greater reduction in pocket depth and bleeding on probing, and more gain of attachment (6,7,16,19,29,31). More evidence is needed to demonstrate the effectiveness of adjunctive therapy with NSAIDs in the presence of genetic factors responsible for the higher production of important pro-inflammatory cytokines such as IL-1β, as the presence of a genetic polymorphism of IL-1B. Aim of this study is to evaluate the effectiveness of the adjunctive therapy with NSAIDs in chronic periodontitis compared to conventional non-surgical therapy in the presence of IL-1β gene polymorphism with clinical parameters and changes in the expression of IL-1β in gingival tissues. Material and methods 1. Selection of patients was made based on clinical and radiographic diagnostic criteria. The study included 30 patients with moderate (loss of attachment from 2 to 4 mm) and severe periodontitis (loss of attachment 4 to 6 mm, pocket’s depth 4-6mm, alveolar bone loss 4-7 mm, measured on conventional radiographs), without a periodontal therapy in the last 6 months, without systemic diseases and without medication in the last 6 months, with a minimum of 20 teeth. 2. Clinical evaluation of periodontal status of patients following clinical parameters measured: Hygiene index - HI, Papillary bleeding index - PBI, probing pocket depth in mm (Pocket depth - PD), loss of clinical attachment in mm (Clinical attachment level - CAL), width of attached gingiva in mm (Attached gingiva width-AGW), gingival recession in mm (Gingival recession - GR), furcation lesions in horizontal probing (Furcation involvement-F) classification of Hamp 1975 and teeth mobility qualification in grades 1 to 3. 3. Patients were grouped according to type of treatment applied in the control group (cause-related non-surgical - scaling and root planning (SRP), and an experimental group (cause-related non-surgical therapy and additional administration of NSAIDs (Aulin - twice 100 mg daily for 14 days). 4. An analysis of gene expression alteration levels of IL-1β in the gingiva of patients with chronic periodontitis before and after the applied non-surgical therapy was made. For this analysis was used one of the most modern methods for testing the amount of inflammatory mediators by gene expression changes of IL-1β monitoring in gingival tissue of patients with 5 periodontitis by PCR (polymerase chain reaction) TagMan RT - PCR (5) . 5. A study of gene polymorphism of IL-1β in material from gingival tissues of periodontitis patients in both groups by the method of single nucleotide polymorphism (SNP). PCR method for IL-1β gene polymorphism detection was applied. 6. Statistical methods. Data were entered and processed with statistical package IBM SPSS Statitics 19.0. Level of significance for rejecting the null hypothesis was chosen as p<0, 05. The following methods were applied: 1. Descriptive analysis - in tabular form is the frequency distribution of the signs at issue, by groups of study. 2. Variance analysis - calculating estimates of central tendency and dispersion. 3. χ2 test and Fisher accuracy test - to check the hypothesis of a link between categorical variables. 4. Nonparametric test of Shapiro-Wilkie - to check the type of distribution. 5. Nonparametric test of Mann-Whitney - for hypothesis testing for difference between two independent samples. Control group (without Aulin) Index ddCt (IL1β) Results and discussion Evaluation of the effectiveness of both kind of nonsurgical therapy administered in this study has been made through changes in gene expression of IL-1β in gingival tissues of patients with moderate and severe chronic periodontitis and established gene polymorphisms IL-1B C [3953/4]T ( rs_1143634) and IL-1B T[-511]C (rs_16944). Table 1 shows the change in gene expression of IL-1β, depending on the applied therapy conventional or non-steroidal anti-inflammatory complemented by an agent - Aulin . The alteration (ddCt) in the expression of IL-1β in the two groups of patients was compared. Patients treated with additional Aulin, register suppression of the expression of IL-1β. Comparative analysis of gene expression in patients taking and not taking Aulin showed that the administration of Aulin have significantly higher average change in gene expression compared to untreated with this drug (table. 1) (p <0.05). Negative values ddCt in patients in the control group reflect a lower degree of inhibition of gene expression. Hence, in patients who were not taking Aulin, the expression of IL-1β is suppressed to a much lesser degree. n 10 X - 1,862 SD 1,461 Experimental group (with Aulin) n SD X 20 0,191 2,033 p 0,016 Table 1: Comparative analysis in the changes of gene expression of IL-1β in control and experimental group. 6 Alleles When comparing the gene expression of IL1β according to presence of gene polymorphisms of IL-1B T [-511] C with borderline significance (p = 0.07) proved the difference between the change in gene expression in heterozygotes and homozygotes for the IL-1B [511] C. The average change is higher in the relevant type of homozygotes genotype (Table 2). n 16 Homozygotes SD X 0,32 2,34 n 14 Heterozygotes SD X -1,39 1,78 p 0,568 Table 2: comparative analysis in the changes of gene expression of IL-1 β according to genotype IL1B[-511] C In a second study of genotype IL-1β C [3953 / 4] T are not found statistically significant differences between changes in gene expression of IL-1β in comparison to patients with homozygotes and heterozygotes in this genotype (p = 0.568) (table 3). Homozygotes N 18 X -0,60 Heterozygotes SD 2,35 n 12 X -0.29 n SD X a 2,26 C 13 0,84 T 3 -1,93 0,91 T/C 14 -1,39b 1,41 Table 4: Comparative analysis in the changes of gene expression of IL-1β according to genotype IL-1B T[-511] C Table 4 shows that patients with C allele (genotype of IL-1B T [-511] C) had significantly greater change in gene expression of IL-1β than those with alleles T and T/C (p<0,05). These data suggest a better healing response to therapy and kave shown consistence with relatively low risk of these patients to develop severe periodontitis (data published in previous post). Therefore, the result of this study indicate that patients with C allele (genotype of IL-1B T [-511] C) have moderate risk of developing severe chronic periodontitits and showed good response to therapy by the change in gene expression of IL-1 β. According to genotype IL-1B C [3953 / 4] T the difference between changes in gene expression of IL1β in patients with allele C, T and T / C have not significant character (p>0.05) (Table 5). p SD 1,78 0,568 Table 3 Comparative analysis in the changes of gene expression of IL-1β according to genotype IL1B C [3953/4] T Alleles C T T/C n 15 3 12 X a -0,70 -0,07 -0,29a SD 2,52 1,39 1,78 Table 5: Comparative analysis in the changes of gene expression of IL-1β according to genotype IL-1B C [3953/4] T *- the same letters show missing of significant differences The investigation results show a higher efficiency of additional anti-inflammatory agent therapy (Aulin®) compared to conventional non-surgical therapy indicated in patients with IL-1β gene 7 polymorphism C [3953 / 4] T and IL-1β gene polymorphism T [-511] C. Conclusions 1. It is established a higher efficiency of adjunctive therapy with anti-inflammatory agent (Aulin®) compared to conventional non-surgical therapy in patients with chronic periodontitis and identified IL1B polymorphism C [3953 / 4] T and IL-1β polymorphisms T [-511] C by demonstrating a high degree of change in gene expression of IL-1β (p<0.05). 2. It is established a better response to initial periodontal therapy in patients with C allele (IL-1β genotype T [-511] C) compared to those with alleles T and T/C (p<0.05). 3. The results showed no statistically significant difference between changes in gene expression of IL1β in response to therapy when comparing patients with IL-1β C [3953/4] T homozygosis and heterozygosis. The findings from this study serve to supplement the understanding of pathogenesis and treatment approaches of periodontitis, greater clarity in the individual planning and evaluation of the applied therapy for chronic periodontitis. Genetic tests determining the presence of gene polymorphisms of IL-1β in clinical practice may be useful in predicting the development of chronic periodontitis and response to therapy and in the interpretation of the results to therapy in individuals with chronic periodontitis. Tests to identify the gene polymorphism of IL-1β can be useful in planning and evaluating the effectiveness of host modulations therapy for inhibition of the production of IL-1β and to serve the planning of future treatment and maintenance of periodontal diseases. Completed research project is under GRANT № 55, № 14/ 2010 contract funded by the Medical University of Sofia, Council of Medical Science. Reference 1. ٭Млъчкова А. Приложението на нестероидните противовъзпалителни средства в лечението на пародонталните заболявания. Зъболекарски преглед 2004; 1:58-66. 2. ٭Попова Хр., A. Mлъчкова. Ефективност на допълнителната терапия с НСПВС (Aулин) върху разпространението на плитките и дълбоки пародонтални джобове при пациенти с хроничен пародонтит (Пилотно изследване). 19-th Assembly of IMAB, Varna-Bulgaria, 7-10 May 2009, p.6 3. ٭Попова Хр., A. Mлъчкова. Параметри на оздравяването при асистирана с нестероидни противовъзпалителти агенти нехирургична терапия на хроничен пародонтит. сп. “Проблеми на денталната медицина”, 2010,том ⅩⅩⅩVІ; част ІІ. 4. ٭Попова Хр., A.Mлъчкова. Ефективност на допълнителната терапия с НСПВС (Aулин) върху разпространението на плитките и дълбоки пародонтални джобове при пациенти с хроничен пародонтит (Пилотно изследване). Journal of IMAB, Annual Proceeding (Scientific Papers), 2009, book 4, 55-57. 5. ٭Попова Хр., А. Млъчкова, М. Кичева. ТagMan RT – PCR метод за установяване нивата на IL-1β и PGE2 в гингивата при пациенти с хроничен пародонтит. сп.“Проблеми на денталната медицина“ 2009, том ХХХV,част ІІ: 815стр. 6. Bennett A., G.Villa. Nimesulide: an NSAID that preferentially inhibits COX-2, and has varios unique pharmacological activities. Exp. Opin.Pharmacother.2000;1:277-284 7. Bezerra M., V. de Lima, V. Alencar, G. Brito, A. Rocha. Selective cyclooxygenase-2 inhibition prevents alveolar bone loss in experimental periodontitis in rats. J Periodontol 2000; 71: 10091014. 8. Borrell LN. & Papapanou PN.Analytical epidemiology of periodontitis. Journal of Clinical Periodontology, 2005; 32(Suppl.6):132–158. 9. Ciancio S. Systemic medications: clinical significance in periodontics. J. Clin Periodontol 2002; 29 (Suppl 2): 17-21). 10. Cobb CM. Clinical significance of nonsurgical periodontal therapy: an evidence-based perspective of scaling and root planning. J Clin Periodontol 2002;29(Suppl.2):6-16. 11. Dinarello A. Biologic basis for interleukin–1 in disease. Blood, 1996; 87: 2095-2147. 12. Dinarello A. The many worlds of reducing interleukin-1. Arthritis Reum 2005;52: 1960-1967 13. Duff W. Cytokines and anti-cytokines. British Journal of Rheumatology, 1993; 32 (1st suppl.): 15-20. 8 14. Duff W. Molecular genetics of cytokines: Cytokines in chronic inflammatory disease. In: Thompson A, Ed. The cytokine handbook, 1994; 2nd edition: 21-30. 15. Duff W. Molecular genetics of cytokines: Cytokines in chronic inflammatory disease. In: Thompson A., Ed. The cytokine handbook, 1998: 2133. 16. Famaey J. In vitro and in vivo pharmacological evidence of selective cyclooxygenase-2 inhibition by nimesulide: an overview. Inflamm Res 1997; 46(11):437-46. 17. Haffajee D., S. Socransky. Microbial etiological agents of destructive periodontal diseases. Periodontol 2000, 1994; 5: 78-111. 18. Hart C. & S. Kornman. Genetic factors in the pathogenesis of periodontitis. Periodontology 2000, 1997; 14:202-215. 19. Hassel T., Harris E. Genetic influences in caries and periodontal diseases. Crit Rev Oral Biol Med 1995; 6:319-342. 20. Holzhhausen M., C. Rossa, E. Marcantonio, D. Spolidório and L. Spolidório. Effect of selective cyclooxygenase-2 inhibition on the development of ligature-induced periodontitis in rats. J Periodontol 2002; 73:1030-1036. 21. Ishihara Y., T. Nishihara, N. Shirozu, E. Yamagishi, M. Koide, K. Amano & T. Noguchi. Gingival crevicular interleukin –1 receptor antagonist levels in periodontally healthy and diseased sites. Journal of Periodontal Res., 1997; 32: 524-529. 22. Kinane D., Attström R. Advances in the pathogenesis of periodontitis consensus report of the fifth European workshop in periodontology. J Clin Periodontol 2005; 32 (Suppl. 6): 130-131. 23. Kornman K. Host modulation as a therapeutic strategy in the treatment of periodontal disease. Clin Infect Dis 1999; 28:520-526. 24. Kornman K., A. Crane, M. Newman, F. Pirk, F. Higginbottom and G. Duff. The interleukin-1 genotype as a severity factor in adult periodontal disease. J Clin Periodontol 1997; 24: 72-77. 25. Mc Devit M., Hwa-Ying Wang, C. Knobelman, M. Newman, J. Timms, G. Duff and K. Kornman. Interleukin-1 genetic association with periodontitis in clinical practice. J Periodontol 2000; 71:156-163. 26. Michalowicz S. Genetic and heritable risk factors in periodontal disease. Journal of Periodontology, 1994; 65 (5th suppl.) :479-488. 27. Nicklin H., A. Weith & W. Duff. A physical map of the region encompassing the human interleukin-1 α, β and the interleukin–1 receptor antagonist genes. Genomics, 1994; 19: 382-384. 28. Novac M., D. Dawson, M.Ryan, C. Drisko, D.Kinane, M. Bradshaw. Combining host modulation and antimicrobial therapy in the management of moderate to severe periodontitis: a randomized, multicenter trial. J Periodontol 2008; 79: 33-41. 29. Pociot F., L. Wogensen, H. Worsaae, J. Nerup. A Taq I polymorphism in the human interleukin-1β (IL- β) gene correlates with IL-1β secretion in vitro. Eur J Clin Invest, 1992; 22: 396402. 30. Salvi G., N. Lang. Host response modulation in the management of periodontal diseases. J Clin Periodontol 2005; 32 (Suppl. 6) 108-129). 31. Salvi G., N.Lang. The effects of non-steroidal anti-inflammatory drugs (selective and non- selective) on the treatment of periodontal diseases. Curent Pharmaceutical Design,vol.11; 2005:1757-1769 32. Tipton D., J.Flin, M.Dabbous. Cyclooxygenase-2 inhibitors decrease interleukin- 1β –stimulated prostaglandin E2 and IL-6 production by human gingival fibroblasts. J Periodontol 2003; 74:1754-1763. 33. Van Dyke T.Control of inflammation and periodontitis. Periodontology 2000, 2007; 45: 158166. Address for correspondence: Assoc. Prof. Dr Chr. Popova Faculty of Dental Medicine, MU-Sofia 1, St. G. Sofiiski Blvd, 1431 Sofia Tel: 0888 75 90 49 Е-mail: hrpopova@yahoo.com 9 Conservative dentistry A comparative study on the use of posts from dental practitioners and students E. Boteva 1 SUMMARY Introduction: In the last decade there is a significant increasing in the post and core restorations after endodontic treatments. Aim: The aims of this study are to find the differences in the use of posts and pins from dental practitioners and undergraduate students: the frequency of iatrogenic mistakes and their use in different types of teeth, what types of post are most common. Material and methods: 1860 x-rays of dental practitioners with 1291 endodontic treatments and 2116 root canals were observed under magnification x5. 150 teeth with 156 posts were included in the study. The second group of participants were patients of 124 students with the same number of teeth. The posts in this group were 314. The applied criteria was: type of the tooth, type of the post, length in the root canal, mesiodistal dimension of each post and iatrogenic errors like – perforations, empty root canals and post bigger than 2/3 of the mesiodistal root canal dimension. Results: There is no evidence of the use of esthetic posts in this study. Most frequent is the use of posts in incisors and premolar teeth in 81,3% from dentists and in 88% from students. The use in molars is respectively 18 and 11,5%. Students use posts and pins is equal, but dentists use more posts than pins. Casted posts and cores are used more from students – 14,9%, than from dentists – 8,9%. These evidences suggest that in dental practices the choice is based mainly on the lower price. Mistakes made from students are in 33,2% of the cases and 45,5% from dental prctitioners. Conclusions: Iatrogenic errors among students are 12,2 and among dentists 12,8%. For better treatment outcomes will be very useful the choice of the posts, the fixation technique and radiographic conttrol to be carefully revised for each patient. Key words: endodontics, posts, posts and cores 1 Assoc.Professor , Department of Conservative Dentistry, Faculty of Dental Medicine, Sofia 10 Introduction The use of posts for reconstruction of dental crowns became a routine practice in the last two decades, not only for incisors but for distal teeth too. Different visions exist in the dental literature about this problem. The traditional approach of replacement of more than one wall or cusp with a post is more or less based on the knowledge of preadhesive dentistry era. There is a long history of the use of posts. Back in 1839 and 1848 posts were already used for restorative treatments of crowns ( Harris, Tomes ). Some authors suggest that if the teeth are not quite destroyed, their durability is longer without posts (Guzy, Trope, Sidoly). Even without massive hard tissue loses, MOD cavities are lowering tooth resistance up to 63% ( Reeh 1989 ). The fracture resistance is related to the amount of remaining dentine, especially in buccolingual dimension and to the amount of preparated root canal ( Stockton ). On the other hand, in the last 15-20 years, prefabricated ready made posts are in use much more often than casted post and cores. Their use is cheaper and much faster (Torbjorner ). In the dental literature eight are the retentive and mechanical factors of posts (Hu.Y.H.): length, diameter, type of post, type of cement and method of cementation (Goss J.M.), dimension of the root canal, its preparation and the place of the particular tooth in the dentition (10-Stockton ). The post and core method can result in iatrogenic errors and complications leading to teeth extractions or bone operative interventions. In our dental literature this problem is published recently only in one literature review and very few of the main problems are looked at: length, diameter, and length and diameter of the root canal and the type of the post (1). Problems like the frequency of use in different groups of teeth (3,12) and the frequency of iatrogenic errors in teaching practice are unknown (2,3). Unknown is also the clinical application of the teaching criteria of their use. Aims 1. To register the differences in the technology of the use of posts from GP,s and undergraduate dental students. 2. To find out the frequency of complications. 3. To find the frequency of use of posts in different groups of teeth. 4. To investigate what types of posts are in use most and how they are used. Material and methods Participants in the first study group are patients of the Dental Faculty in Sofia between 2008-2010. All their previous posts and cores fixed not from students were observed on x-rays, three per tooth, n=1860 total. All endodontically treated teeth were 1291 with 2116 root canals, from them 150 teeth were with 156 posts, two of them fixed on teeth with periapical pathology. Participants in the second group are patients of 124 dental students from 2008-2010, followed up with x-rays. Total number of endodontically treated teeth is 1291 with 2116 root canals. Our follow up was on 319 teeth with 319 posts, plus 5 fixed on teeth with periapical lesions. This makes 2.6 from the required 7 per student under the requirements of the clinical course. Only 47 of these are casted, the rest more than half were not followed up. X-rays X-RAYS of the treated teeth on Dick dental radiographs are observed and registered for: 1. Type of the tooth with post : incisor, premolar, molar. 2. Type of the post: screw post, cemented or casted posts. 3. Length in the root canal:<1/2, up to ½, up to 2/3. 4. MD dimension of the root canal <1/3, up to 1/3 and up to 2/3. 5. Iatrogenic errors >2/3 and perforations. 6. Posts on large periapical lesions in 265 treated lesions. 7. Posts in empty root canals Exclusion criteria: x-rays with poor quality, and teeth out of correct focus. Results and discussion From 156 posts on 150 teeth 53 or 35.3% were used for front teeth restorations. For restorations of premolar teeth 69, 46.0% were used and only 23, 15.2% were fixed on distal teeth. Only few were the posts fixed of third molars. 11 According to the type of fixation 94 were cemented – 60.3% and 48, 30.8% were screw posts (endo pins). Only 14, 9.0% were the casted post and cores. Less than ½ of root canal length were 80, 51.3%, up to ½ were 49, 31.4% and up to 2/3 were 17, 10.9% of the posts. Less than 1/3 of the MD dimension were 37, 23.7%, up to 1/3 – 38, 24.4% and up to 2/3 were 50 or 32.05%. Over preparation of root canal dentine Type of tooth and sizes over 2/3 of MD dimension were found in 21 teeth or 13.5%, 4 perforations, 2.6% and in 11 cases – 7.0% were cemented in not filled root canals. Type of post MD dimension Errors Upto2/3 >2/3 30 125 I163 PM 119 М 37 Cem 132 Pins 135 Cast 47 <1/3 45 Upto1/3 125 <1/2 60 43 13 60 42 16 35 45 27 10 ½ 55 35 14 44 48 13 4 50 47 5 2/3 48 35 10 28 45 18 6 30 Table 1: X-ray valuation of posts of the GP,s, 3 Ro gr per one post (n=15) 51 15 Lenght Lenght Type of tooth I 53 PM 69 М 23 МD dimention Type of post Cem. 94 Pins 48 Cast 14. <1/3 37 Upto1/3 38 <1/2 29 41 8 53 25 2 35 18 ½ 21 20 11 30 12 7 2 16 2/3 3 8 4 9 5 3 4 Table. 2 X-ray valuation of the posts of the students, 3 Ro gr per post (n=319) From all endodontically treated teeth 1291, 50% were restored with posts and half were followed up 319, according to the protocols. From these 319, most were used for incisors 163, 52.5% and premolars 119, 37.3% and less in distal teeth 37, 11.5%. In relation to the method of fixation 132 were cemented, 42%, 135, 42.9% were pins and only 47, 14.9% were casted. Shorter than ½ of the root canal length were 116 posts, up to ½ were 104 and up to 2/3 - 93 posts. Less than 1/3 of the MD dimension were 45 posts, up to 1/3 125 and up to 2/3 125 too. Over preparation of dentine in the root canal and posts bigger than 2/3 were found in 30 patients and only in one case a perforation. Upto2/3 50 18 24 8 Errors >2/3 21 8 9 4 In both groups in 457 posts esthetic posts are not found. Three figures with 13 x-rays of different posts are available in the original paper in the magazine Problems of dental medicine 2011,37,2, p.15-16 After treatment on present periapical lesions 2 posts were fixed from GP,s and 5 from the students. This is understandable with the lack of time for follow up of the cases. In the practice the mistakes concerning fixation of posts in empty root canals were more often (7% and 2,8%) due to the tutors control among students and to so called “routine” among practitioners. Another iatrogenic error was an over preparation of the dentine walls in 13,5% in GP,s and 12 9,4% in the students. Perforations were 4 in the practice and only 1 in the students group, although students patients were twice more. Summarizing the complications the GP mistakes were 23,1% and 12,2% were they in the students group. Non effective, short and thin posts were 22,4% and twice less 11% among students. Only the short posts, with length less than ½ of the root length were 80 – 51,3% fixed from GP,s and 116 – 36,4% fixed from students. This makes all together poor quality of the posts in the dental practice 45, 5%. Comparing this data with the undergraduates – 33,2% suggests that the final step of the endodontic treatment can compromise the whole treatment. The mistakes in the treatment of front teeth were very often, nearly in half of the cases. In incisors the access is not difficult the root canals are straight and the visual inspection is easy. The errors show that the accuracy in the choice anа technology is very poor. Casted posts and cores were rare due to the time consuming technology and higher price. The advantages of prefabricated posts were published in 2010 on 112 teeth followed up for a period of 10 years (3) and in 2007 (2) in 317 patients both in clinical Reference 1. Ж.Миронова, Р.Василева. Съвременни подходи в употребата на РЩ. Дентална медицина, 2, 2008, с.137-141 2. Bolla M. et all. Root canal posts for the restoration of root filled teeth. Evid.Based Dent. 2007,8,2,pp.42 3. Gomes – Polo M.et al.A 10 year retrospective study of the survival rate of teeth restored with metal prefabricated posts versus cast metal posts and cores. J Dent.2010,Aug. 4. Goss J.M. Radiographic appearance of titanium alloy prefabricated posts cemented with different luting materials. J of Prosthet.Dent.1992, 67, 5, 632 5. Guzy G.E. , Nicholls J.I. In vitro comparison of intact endodontically treated teeth. Endod.Dent.Traumat. 1985, 1,108-11 6. Harris.C.A.The Dental Art.,1839, Baltimore, Armstrong and Berry, pp.305-347 7. Hu Y.H. et al Fracture resistance of endodontically treated anterior teeth restored with four studies. Most mistakes were made when screw posts were fixed -6 cases. Conclusions 1. Esthetic posts were not found in this study in both groups. 2. Posts are use most in the treatment of incisors and premolars and in molars only 18-11,5% of the cases. 3. Students use equally screw posts and cemented posts, GP,s use more cemented posts. Casted posts were used more from the students- 14,9% to 8,9%. 4. The choice of the posts most often is related to the lowest possible price. 5. Poor fixation is more often in GP,s 45,5%, compared with 33,2% in students. 6. Useful recommendations for the practice are: better attention of the the choice of the posts and their combination with different materials, treatment methods and techniques. A x-ray follow up can be essential for a good treatment outcome. post core systems. Quint.Int.2003. May, 34,5,pp.349 - 53 8. Mentink A., Meeuwissen R., Kayser A., Mulder J. Survival rate and failure characteristics of the all metal post and core restoration. J Oral Rehabil, 1993, 20, 455-61 9. Reeh E.S., Messer H.H., Douglas W.H. Reduction in tooth stiffness as a result of endodontic and restorative procedures. J Endodontics 1989,15,512 10. Stockton L.W. Factors affecting retention of post systems: A literature review, The journal of prosthetic dentistry, 1999, 81, 4, 380-384 11. Trope M, Maltz D.O., Tronstad L. Resistance to fracture of restored endodontically treated teeth. Endod. Dent.Traumat.1985, 1, 108-11 12. Torbjorner A.,Karlsson S., Odmann P.A. Survival rate and failure characteristics for two post designs.J Prosthet .Dent.1995, 73, 4 Address for correspondence: Dr. Ekaterina Boteva Faculty of Dental Medicine, MU-Sofia 1, St. G. Sofiiski Blvd, 1431 Sofia 12 Conservative dentistry Comparison of the root canal obturation methods in the preclinical endodontics E. Boteva 1 SUMMARY Introduction: The Step Back root canal preparation technique and cold condensation are methods taught worldwide. Recently condensation is replacing the conventional root canal fillings, although they are not universal by definition, indicators and contra-indicators. Aim: The aim of the present study was to valuate the quality of root canal fillings with cold condensation and conventional method and the produced microleakage. Material and methods: 320 extracted, sound human molars, with 797 roots and 898 root canals were used in the study. Cold condensation was used for distal canals of lower molars and lingual canals of upper molars. Buccal and medial canals were filled with pasta and central Gutta cone. One to three years after treatment teeth were treated for 24 hours in 2% methilene blue, rinsed up to 3 hours in running tab water and dried for 24 hours. All roots are cut twice, 1/3 from apex and 2/3 from apex. Results were observed under magnification x5. Higher microleakage was found in the cold condensation roots in their firs third (p<0.05). Under the conditions of thi study the conventional obturation method was found to prduce lower microleakage. Conclusions: The use of lower number of Gutta cones, but bigger as size is recommended. Key words: root canals, obturation, endodontics. 1 Assoc.Professor , Department of Conservative Dentistry, Faculty of Dental Medicine, Sofia 14 Introduction The Step Back root canal preparation technique and cold condensation are methods taught worldwide. They are present in 83% of the courses in the USA and in all three faculties in Bulgaria (6). Recently condensation is replacing the conventional root canal fillings with similar use 89,6% and 100%, Although they are not universal by definition, indications and contraindications. According to the dental literature the mean rates of success of endodontically treated teeth is 7,5 years which is a very short duration. Several studies are looking at the clinical qualities of the endodontically treated teeth from 1987 to 2005 (7,5-13). In this mentioned studies the frequency rates of failures are quite large from 21,7 to 63% and the success rates even larger from 14% in Germany to 50% in Denmark in the year 2000. Most authors accept 60-70% as successful scores (5-13). It is well known that this rates decrease from incisors to molars. The aim of the present study was to evaluate the quality of root canal fillings with cold condensation and central cone method during the endodontics preclinical exam. To compare the microleakage between dentine and root canal filling material and to compare the efficiency of both methods. Material and methods TEETH: 320 extracted, sound human molars, with 797 roots and 898 root canals were used in the study. Most teeth from the exam of four different tutors and lecturers between 2004 and 2008 are included in the study. Techniques Standard root canal treatment of sound matured teeth was performed. Working length was detected with x-ray method. Mechanical preparation was with the Step Back method and all canals were medicated with 3% sodium peroxide and with 0,5% NaOCl. Obturation Cold condensation was used for distal canals of lower molars and lingual canals of upper molars. Buccal and medial canals were filled with pasta and central Gutta cone. Microleakage After keeping the teeth in the same conditions one to three years after treatment they were treated for 24 hours in 2% methilene blue, rinsed up to 3 hours in running tab water and dried for 24 hours. All roots are cut twice, 1/3 from apex and 2/3 from apex. Results were observed under magnification x5. 1554 cuts two for each tooth were done with diamante blades and all teeth were rinsed well under tab water. The results were registered on the basis of presence or absence of microleakage and if there is presence : 1/3 or 2/3 of the space around of the filling. Results Significant differences in the groups of different lecturers in the department were not found. This was the main reason all teeth to be presented in the table 1. It is well established from the table that the method is standardized. Higher scores of microleakege towards the crown are present in the cold condensation group only up to 1/3 of the roots. A possible explanation of this fact can be lower pressure in the apical zone around the apical stop. CCT with pasta and single cone is surprisingly successful. This data is giving a better outcome of the results than the x-ray controls after the treatment. According to the x-rays our mean marks are 4.5-5.25. Usually on this x-rays the examiners registers deviations in the length of the root canal filling, air bubbles or fractured instruments (1). 15 Method: Penetratio n of methilene: CC 1/3 Total n Number of root canals 337 1/3 Up to 1/3 1/3 CC CC CCT CCT CCT Mean in group % 94.8 16.6 56 16.6 Number of root canals 569 66 10.5 15.9 96 16 16.6 Up to 2/3 34 7.5 22.1* 125 20.8 16.6 1/3 Full 64 10.6 16.5 146 24.3 16.6 1/3 0 176 29.3 16.6 202 33.6 16.6 2/3 Total n 342 57 16.6 682 113.6 16.7 2/3 Up to 1/3 99 16.5 16.6 155 25.8 16.6 2/3 Up to 2/3 55 9.2 16.7 154 25.6 16.6 2/3 Full 47 7.8 16.6 133 22.2 16.7 2/3 0 141 23.5 16.6 175 29.2 16.7 Part of the root canal Mean in group % Table 4 Microleakage in cold condensation (CC) and in central cone technique (CCT) ,*p<0.05 Discussion It is well known from the literature that all materials have microleakage at least up to one month after root canal obturation (2). In the dental literature higher microleakage has been observed between pasta and gutta cones, than between pasta and dentine. Due to this fact is the established in this study higher microleakage in the CC group. For CC root canals are enlarged more in the apical zone, where condensation and pressure are more difficult. Aiming for a higher number of cones in one root canal which was a teaching dogma in the department is obviously not the correct approach. Fillings with smaller number of Gutta cones for CC can be much better for best apical sealing results (12, 13 ). Comparing our data with the one from Cardiff, Wales, UK, from 157 teeth only 13% are acceptable during the clinical course, likely due to gaps in the preclinical teaching skills (9). The quality of preclinical endodontics including a well balanced clinical number of cases are a very important basis for a successful clinical outcomes. Success and failures in root canal treatment are investigated from 306 published clinical trials from 1966 to 2004, Glickman (8). Unfortunately the quality of teaching during the preclinical course is not investigated in the literature. Conclusions 1. Adhesion in root canals in both root canal obturation techniques, teached in the department of Conservative dentistry in Sofia is very good. 2. Under the conditions of this study CCT seems to be better for students practicals method for root canal obturation, when Step Back preparation technique is applied. 3. The teaching of preclinical endodontics in Sofia is very well standardized and very well practiced in all lecture courses up to year 2008. 16 Reference 1. Ботева Е. Изследване на предклиничното обучение по КЗ – ендодонтска част. Зъболекарски преглед ,2011,2 2. Ботушанов П. Ендодонтия – теория и практика 1998, Автоспектър, Пловдив, 401 – 418 3. Дачев Б. и кол. Ръководство за практически упражнения по пропедевтика на терапевтичната стоматология. 1990, Медицина и физкултура, София 47-48 4. Ендодонтия 2002, под редакцията на Б.Инджов, Медицинско издателство Шаров 5. de Chevigny C. et al. Treatment outcome in endodontics : The Toronto study – phases 3 and 4. JOE, 2008, 34,2,130-137 6. Cailleteau J.G., Mullaney T.P. Prevalence of teaching apical patency and various instrumentation and obturation techniques in US dental schools. J OE, 1997, 23, 394 – 6 7. Eleftheriadis G.I., Lambrianidis T.P. Technical quality of root canal treatment and detection of iatrogenic errerors in an undergraduate dental clinic. Int.Endod J. 2005, 38, 725 – 34 8. Glickman G., A.Gluskin, W. Johnson, L.Jarshen The crisis in endodontic education: current perspectives and strategies for change. JOE 2005, 31,4,225 - 261 9. Hayes S.J., Gibson M., Hammond M., Brayant S.T., Dummer P.M. An audit of root canal treatment performed by undergraduate students. Int. Endod. J. 2001, 34, 501 –5 10. Qualtrough A.J., Whitworth J.M., Dummer P.M.Preclinical endodontology: an international comparison. Int. Endod.J. 1999, 32, 406 – 14 11. Schulte A., Pieper K., Charalabidou O., Stoll R., Stachniss V. Prevalence and quality of root canal fillings in a German adult population. A survey of ortopantomograms taken in 1983 and 1992. Clin.Oral Invest. 1998, 2, 67 - 72 12. Sonntag D. et al. Pre-clinical endodontics: a survey amongst German dental schools. Int. Endod. J. 2008, 41, 863 – 868 13. Wu MK., Shemesh H., A.R. Wesselink. Limitations of previously published systematic reviews evaluating the outcome of endodontic treatment. Int. Endod. J. 2009, 42, 8,656 Address for correspondence: Dr. Ekaterina Boteva Faculty of Dental Medicine, MU-Sofia 1, St. G. Sofiiski Blvd, 1431 Sofia 17 Paediatric dentistry Oral status of children from Rousse district – Epidemiological research, part of National program for prevention of oral diseases in children from 0 to 18 years in Bulgaria M.Rashkova 1, L.Ribagin1, Ts. Doganova2, V.Alexieva1 SUMMARY Introduction. Epidemiological research in Rouse and Rouse region is a part of a National Prophylaxis program of the children in Bulgaria. Materials and methods. Epidemiological research of oral status of 723 children, using WHO method, was held in Rouse and Rouse region. Children are at the age of 6, 12, and 18 years old, divided in groups of 60 children according their sex and place of living (town and village). Methods include evaluation of dental caries (DMF), the results for diagnostic D3 was used. Oral hygiene (OHI), periodontal status of 18 years old children (CPITN), existing orthodontic deformation and fluorosis were considered. Results show that DMF- indexes of 6 years old children are 2,70±3,64, of 12 years old children – 3,80±2,67, and 18 years old - 4,9±3,36. Research shows that dental caries rises with the age. There are no significant differences between boys and girls from town and village. Oral hygiene index in 12 years old children is highest : OHI - 1,86±1,01, lower in 18 years old children 1,40±1,01 and is lowest in 6 years old children - 0,94±1,86. Half of examined children have orthodontic deformation and 1, 9% of children have dental fluorosis. 45% of 18 years old children are without periodontal diseases, but the rest of them have mostly localized gingival diseases. Conclusion: The oral status of the children in Rouse and Rouse region is with a complex pathology, as caries progress with the age. Oral pathology and orthodontic deformity affect more than the half of the children, included in the investigation. This refers a new preventive method in the treatment with the motivated participation of both children and parents. Key words: epidemiological research, National prophylactic program, dental caries, oral hygiene, periodontal diseases, orthodontic deformity. 1 2 Faculty of Dental Medicine – Sofia, Department of Pediatric Dentistry Dental center - Rouse 18 Introduction Dental caries is the most common chronic disease from the of age 5 to 18. (12.16). There has been a decrease in dental caries in many countries of Western Europe, North America and others at the end of the last century. While in 1973, DMFT in 12 year group was 4.8 , in England and Wales the index in the same age group dropped to 1.2 in 1993. In Sweden, in 1964 DMFS (on surfaces) in 12 year old group was 40, compared to 1994 when the same index was less than 1. In the Netherlands in 2008 DMFT a group of 12 year old children was registered with less than 1 ,whereas in Canada the caries-free dentition was 41% (12. – 19 years old) (8). In the U.S. in 2007. over 50% of 5-9 year old children have at least one cavity or filling (16). Meanwhile, epidemiological studies show that DMFT index in Eastern Europe is still high: in 1994. in Latvia, DMFT, at 12 years was 7.0, in Poland - 5.1, and in Hungary - 4.1 (8). In China (2007) have studied 2014 children aged 3-5, in the WHO criteria and reported that 55% of the children had caries, 14% had "rampant caries". In 5 year old children, 76% had caries and DMF-T was 4.5 (10.19). In 2003, WHO published the "World Report on oral health - continuous improvement of oral health in the 21st century - new goals" (15). In 2007 the 60th World Health Organisation (WHO) adopted the resolution "Oral health: action plan for promotion and integrated disease prevention" (WHA60.17). These are the documents that govern the programs and activities to reduce tooth decay worldwide (20). What is the status of the problem in Bulgaria? Epidemiological study was conducted on children in 1982 regarding the WHO standards in 8 major Bulgarian cities (N. Atanassov et al.). The results showed: caries-free temporary teeth of children 6 years old - 12.77%; caries-free permanent teeth of children 6 years old - 80.84%; DMFT 12 year olds 3.85; DMFT 18 year olds - 7.61; DMFT 35-44 year olds - 16.53; DMFT 65 - 17.42, 18 year olds with at least three healthy sextants by CPITN - 62.11% Data are quoted on the first national meeting of the Association of DDM, November 2011. Hisar (8). Peneva, Kukleva, Kondeva in different epidemiological studies discovered that tooth decay in Bulgaria varies from 3 to 8 DMFT in children of different age groups (1,2,3). In 2008. Peneva and Rashkova made epidemiological research for scientific purposes, which showed DMFT – 6 at 6 year old children in diagnostic threshold D3, which rose to 10 when reversible carious lesions (diagnostic threshold D1, D2) were includeed. 80% of children at the age of 6 had caries. In the group of 12 year old children, 80% had caries, and DMF-T was 4,3 in diagnostic threshold D3, and rose up to 7 in the diagnostic threshold D1. (4,5,6,7). On 16th of April 2009 National program for prevention of oral diseases in children 0-18 years was adopted in Bulgaria with Protocol № 15 of the Council of Ministers. (8). In 2010 national epidemiological survey was conducted across the country to record the oral health of children in Bulgaria. Such large-scale epidemiological study has not been performed in Bulgaria for over 20 years. The aim of this article is to present an epidemiological study of oral status of children in Rousse District as part of the National program for prevention of oral diseases in children 0-18 years in Bulgaria. Material and methods The epidemiological study was conducted on 723 children 6, 12 and 18 years old. Age groups were formed on the recommendation of WHO as target matches for this type of study. Urban and rural populations were examined. Formed groups are represented in the following table 1: city sex 6y. 12y. 18y. 1♂ 61 60 57 2♀ 61 60 63 3♂ 60 60 4♀ 60 60 Table 1: Distribution of studied children. village 59 60 For oral status registration, modified WHO card was used for the needs of the study. Caries detection with diagnostic threshold at D3 was registered (clinically visible caries in dentin with cavity) (6).In this study oral-hygiene status (OHI-S), periodontal status by CPITN, presence of orthodontic anomalies and dental fluorosis were also included. 19 From a statistical standpoint a SPSS-16 program was used. The results are summarized in the following chart 1. 4,9 3,8 2,7 DMF Kids at 6y. Kids at 12y Kids at 18y. Chart 1: Tooth decay in children examined by age group The chart shows that DMF-T index rises with aging. The differences between the age groups were statistically significant (P <0,05). On average, three teeth of 6 year olds were affected by caries, 4 teeth in 12 year olds and 5 teeth in 18 year olds. Number of caries lesions had fillings, others had tooth extractions due tooth decay complications. The results are divided by age groups. Tooth decay in children 6 years old. The results are presented on the chart 2 and table 2, 3. Chart 2: Tooth decay in 5-6 year olds-DMF (T + t) Present DMF (T + t) at 5 to 6 year old children was formed by the sum of carious lesions of temporary and permanent teeth. No significant difference was observed between boys and girls and between children from urban and rural population (P> 0,05). There is a 20 slight tendency of lower tooth decay amongst girls. The distribution of carious deciduous teeth and teeth with fillings in children at the age of 6 is presented in the following table 2. Locations sex n d f Df mean ±SD mean ±SD city 1♂ 61 2,05±2,64 0,43±1,11 2♀ 61 2,36±3,16 0,23±0,74 village 3♂ 60 2,55±3,00 0,47±1,18 4♀ 60 2,12±2,86 0,25±0,81 t р t1,2=0,59 t1,2=0,32 Р>0,05 t2,4=0,8 t3,4=1,16 t1,3=0,39 Table 2: dft of deciduous teeth in 6 years children Legend: d- carious teeth, f- filled teeth, df-carious and filled deciduous teeth Tooth decay presence in temporary teeth of children at 6 years of age has no significant difference between girls and boys, and between nonrural and rural population (P> 0.05). The table shows an interesting relationship between caries and restored with fillings teeth: boys - 5 teeth with caries vs. only Locations sex n Dmean±SD city village t p one filling; girls - 8-10 carious teeth vs. one filling. No difference was observed between the ratio of carious teeth and restored teeth between children from city and rural origin. The distribution of carious teeth and restored teeth at 6 years old children are presented in the following table 3. DMF M F mean±SD 1 ♂ 61 0,03±0,25 0 0 0,03±0,25 2 ♀ 61 0,11±0,52 0 0 0,20±0,81 3 ♂ 60 0,05±0,22 0 0 0,05±0,22 4 ♀ 60 0,03±0,25 0 0 0,03±0,25 t1,2=1,10 t3,4=0,38 Table 3: DMF-T of permanent teeth in 6 years old children p>0,05 The results show no difference between girls and boys, and between children from either the city or country. It is noteworthy that in all age groups there is no filling on permanent teeth. This is of particular concern,because the age of 6 is the onset of the occlusal caries in permanent molars. As shown it is not reported neither by dentists, where an apparent mean±SD 2,46±3,12 2,30±2,55 2,92±3,27 2,37±3,04 t1,2=0,32 t3,4=0,95 t1,2=1,5 t3,4=0,38 lack of a preventive approach is present, nor by the parents of the children who probably are not aware that their children already have tooth decay in permanentmolars. Tooth decay in 12 years children. Results are presented on the next chart 3 and Table. 5. 21 DMF 4,07 3,92 3,77 3,46 ♂ ♀ ♂ city ♀ vilage Chart 3: Tooth decay in 12 year olds DMF (T + t) Tooth decay in 12 year old chldren did not differ between boys and girls and between from urban and rural populations(P> 0,05). DMF index is between 3.5 and 4. Comparing our results obtained with the global objectives for 2010 by WHO (20), which recommends up to 3 DMF for 12 year olds may say that in the city of Ruse and Ruse region overall, the average tooth city village t Р decay is relatively close to the recommended by WHO. There is a part of children 12 years of age, still having deciduous teeth, which decays are not a significant part of total tooth decay. It is presented in the following table 4. sex n mean±SD 1♂ 60 0,83±1,41 2♀ 60 1,10±1,70 3♂ 60 1,18±2,10 4♀ 60 0,97±2,28 P> 0,05 t1,2=0,93 t3,4=0,54 Table 5: Tooth decay in deciduous teeth in 12 years children The mean DMF-t index of 12 year old children, includes primary teeth caries or restored with fillings temporary teeth. Tooth decay in permanent teeth of 12 year olds is presented in the following table 5 including the distribution of caries, fillings and extracted teeth due of caries. 22 village t Р D M F mean±SD mean±SD mean±SD DMF 1 ♂ 60 2,03±1,86 0 0,93±1,22 Общо* 0,93± 2 ♀ 60 1,93±2,05 0,02±0,13 0,92±1,28 1,24 2,87±2,65 3 ♂ ♀ 60 60 2,45±2,36 2,34±2,15 0 0 0,57±1,07 0,52±0,80 0,55± 2,83±2,4 2,87±2,22 sex city nn 4 t*=2,66 t1,2=1,10t3,4=0,38 0,95 р<0,05 mean±SD 2,93±2,20 t1,2=0,15t3,4=0,08 Table 5: Tooth decay in permanent teeth in 12 years. Children restored with fillings teeth than the urban children. This fact is supported with statistical confidence (p <0,05). Tooth decay in 18 year olds. The results are shown in chart 4 and Table. 6. The table shows that there is no significant difference of DMF-T for 12 years old children of rural and nonrural populations and between boys and girls. In the whole group there is only one child with a tooth extraction due to caries, which is in the group of girls from the city itself. It is noteworthy that the ratio of carious teeth and restored with fillings teeth is 2:1, while the rural population at 12 years have twice less DMF 5,29 4,97 4,6 ♂ 4,73 ♀ city ♂ ♀ village Chart 4: Tooth decay at 18 year old children (DMF-T) 23 Locations city village Т Р sex n D mean±SD M mean±SD F mean±SD DMF mean±SD 1 ♂ 57 2,40±2,37 0,04±0,18 2,18±2,52 4,6±3,21 2 ♀ 63 2,14±2,40 0,06±0,3 2,81±2,2 4,97±3,13 3 ♂ 59 2,17±2,45 0 2,46±2,38 4,73±4,22 4 ♀ 60 Р> 0,05 2,80±2,76 0,05±0,28 2,57±2,41 5,29±2,76 t1,2=0,63 t3,4=0,85 t1,2=0,59 t3,4=1,31 t1,2=0,61 t3,4=1,33 t1,2=1,47 t3,4=0,48 Table 6: Distribution of 18 years. children in Rousse Distric performance of the DMF-T index are almost the most common teeth linked to tooth There is a trend that correlates the increase in DMF decay. Unfortunately there are extractions due to with age, for instance an increase in the number of caries and its complication. Nine children from 239 DMF to 5 in 18 years old children. Again, there si no registered in this group had an extracted tooth because differences between boys and girls and children from of caries, which represents 3.76% of the children. urban and country areas (P> 0.05). Proportion of children without caries are grouped There are no differences between the number of together in three age groups. The results are presented teeth with tooth decay of children in urban and in Table 7. country areas and between boys and girls. Filled teeth 5 -6 years. city village total city 37,7% 41,5% 39,6% 22,3 % Table 7: Proportion of children without caries 12 years. village 20,8% total 21,6% city 19,2% 18 years. village 3,4% than in the city (p <0.05). This trend is alarming, especially since childhood is the most suitable period for prevention and halting the development and progression of tooth decay. 2. Oral - hygien status of children from Rousse region. Summarized results are presented on chart 5. It is noteworthy that children without caries decreased rapidly with age. They are approximately 40% of 6 years old children, twice as less in 12 years old children and only 11% of children around 18 years. Children without caries are less in the country OHI 1,4 Kids at 18y. 1,86 Kids at 12y. 0,94 Kids at 6y. 0 Chart 5: OHI of children studied 0,5 total 11,3% 1 1,5 2 OHI 24 The chart shows that oral hygiene index (OHI) of 6 year old children on average is less than 1, which is explained by lesser plaque retention in temporary teeth, despite the insufficient oral hygiene linked to these children. In the group of 12 year old children, OHI is rising and close to 2. Neglect of oral hygiene in this group of children is explained by puberty. In 18 year old children a drop in OHI is reported because of an improved oral hygiene. 30% 3. Teeth and jaw deformities in children from Rousse region. The results are shown in chart. 6 and Table. 8. 45% without DFD light DFD 25% severe DFD Chart 6: Dento-facial deformities (DFD) in children studied Children without teeth and jaw deformities are approximately half of all examined children. The rest are distributed amongst children with mild to severe orthodontic and dentofacial deformities, the milder ones are prevailent. This is a fact that requires special attention, especially since a minor part of children examined had an orthodontic treatment during the examination. The distribution of teeth and jaw deformities studied in children by age groups is shown in table 8. age groups without GFD 1-st degree 2-nd degree total Kids at 6y. number 164 % 67,5% number 45 % 18,5% number 34 % 14,0% number 243 % 100% Kids at 12y. 71 29,5% 58 24,0% 112 46,5% 241 100% Kids at 18y. 92 38,5% 74 31,0% 73 30,5% 239 100% Independent t1,2=9,05 T-test P<0,05 Table 8: GFD surveyed children ages t1,2=1,50 P>0,05 t1,3=4,44 P<0,05 25 There are significant differences in the distribution of orthodontic deformities and severity in all three age groups (X2 = 96.15, P <0.05). Children without orthodontic deformities are significantly more in the group of 6 year old children (P <0,05). Mild orthodontic deformities are distributed evenly in the three age groups. Severe orthodontic deformities are less at 6 year old children (P <0,05), affecting approximately half of the 12 year old children and one third of the 18 year old children. 4. Periodontal status of 18 year old children from Rousse region. CPITN index was used to objectify periodontal status for epidemiological studies adopted by WHO. The results are presented on the next charts 7,8 and Table 9. CPITN 34% with code 0 45% with code 1 21% with code 2 Chart 7: Periodontal status in '18 children 45,20% 20,90% 11,70% 7,50% with 6 sextants 5,90% with 4 sextants 6,30% 2,50% with 2 sextants Chart 8: Healthy sextants by CPITN at 18 years old with 0 sextants 26 group kids Boys Girls total Х2 code 0 numbar % 46 39,7% 62 50,4% 108 45,2% CPITN code 1 numbar % 30 25,9% 20 16,3% 50 20,9% code 2 numbar % 40 34,5% 41 33,3% 81 33,9% Х2 = 4,181 Sig=0,124 total numbar 116 123 239 % 100% 100% 100% P>0,05 Table 9: CPITN at 18d. children, disaggregated by gender 45% of children at 18 years of age have a healthy periodontium. In 34% code 2 was registered, which means significant gingival inflammation and calculus in at least one of the examined sextants, without affecting the alveolar bone. In 21% of children mild gingival inflammation is was noticed - code 1. There are no reliable differences in periodontal status between boys and girls (P>0,05). The distribution of healthy sextants in 18 years old children is presented to the chart 8. Almost half (45.2%) of the children studied, were with 6 healthy sextants. These are children with a healthy periodontium. 34.3% of children had 5,4 or 3 healthy sextants. The share of children with 0, 1, 2 healthy sextants was 20.5%. These are children with severe generalized gingival inflammation. It can be concluded that children from 6 to 3 healthy sextants were 79.5%. 5. Comparison of the results of an epidemiological study of children from district of Rousse with the global objectives of the WHO for 2010. WHO - recommended for the following purposes oral The District Rousse, in 2010. results of the WHO health for 2010: criteria are: 50% of children 5-6y., not be affected by caries; 36.6% of children 5-6y. are not affected by caries; Children of 12 years with no more than 3 DMF; Children of 12 years are with 3,8 DMF; 85% of 18 year olds do not have a tooth extracted; 96.24% of 18 year olds have no a tooth extracted; 90% of 18 years of age to have 3 healthy sextants by 79.5% of 18 years of age have three healthy sextants by CPITN. CPITN. Table 6: Comparison of the results of an epidemiological study of children from district of Rousse with the global objectives of the WHO for 2010 27 Comparative analysis of WHO criteria shows that 36.6% of 6 year old children are free of caries, which is lower than recommended by WHO. In 12 year old group DMF index is close to the benchmark. 18 year old children in our study had teeth extracted 10% more than recommended. Children with a healthy periodontium up to 3 sextants in our study were 10% fewer than recommended. Although our indicators are close to the recommended by WHO, the analysis of the oral status of children in Rousse region shows a lack of preventive approach in the treatment of tooth decay, untreated orthodontic anomalies and in half of the children - gingivitis of varying severity. Conclusions 1. Children of Rousse District have an average of 3 tooth caries at 6 years of age, 4 at 12 years and 5 at 18. There are no differences between boys and girls and between children from the city or country in the area. 2. The proportion of children without tooth decay sharply decrease with age to reach 11% at 18. 3. Oral hygiene deteriorated significantly in 12 year olds and improved in 18 year olds. 4. Over 50% of children have orthodontic deformities. 5. 45% of 18year old children had a healthy periodontium, and the rest had mainly localized gingival inflammation. Reference 1. Кондева В., М.Куклева, А.Ишева, С.Рималовска. Оклузален и проксимален кариес при ученици на 14 години – сравнително проучване. Научни трудове на съюза на учените Пловдив, 2008; т. 11:391-393. 2. Кондева В., М.Куклева, А.Ишева, С.Рималовска. Честота и поларизация на зъбния кариес при деца на 12 и 14 години от гр. Пловдив – сравнително проучване. Научни трудове на съюза на учените Пловдив, 2008; т. 11:387-390. 3. Кондева В., М.Куклева, С.Рималовска, А.Ишева. Епидемичност и честота на зъбния кариес при деца от 7 до 17 години от гр. Пловдив – сравнително проучване. Научни трудове на съюза на учените Пловдив,2008; т. 11:383-386. 4. Пенева М, М. Рашкова, Л. Дойчинова Избор на диагностичен праг за съвремнното епидемиологично проучване на зъбния кариес. Проблеми на денталната медицина, София, 2007, 33,2,47-56. 5. Пенева М, М. Рашкова, Л. Дойчинова. Епидемичност на зъбния кариес при деца и юноши у нас при различен диагностичен праг. Проблеми на денталната медицина, София, 2007, 33,2,37-46. 6. Пенева М. Зъбният кариес през 21-ви век. Изд. Изток-Запад, 2008, 290стр. 7. Пенева М, Пътят за преминаване от оперативно към неоперативно превантивно лечение на зъбния кариес – докторска дисертация 2008г. 8. Шарков Н. 1-вата национална среща на асоциацията по ДДМ, ноември 2011г. гр. Хисар, цитирани данни от: CED Manual of Dental Practice; The Oral Health Survey Module was developed for Statistics Canada’s Canadian Health Measures Survey (CHMS) 2007-2009 9. Bratthall, D. Estimation of global DMFT for 12-year olds in 2004. Int Dent J 2004;55:14-18. 10. Du M, Luo Y, Zeng X, Alkhatib N, Bedi R. Caries in preschool childrenand it’s risk factor in 2 provinces in China. Quintessence Int 2007;38:143151. 11. Dye BA, Tan S, Smith V, Lewis BG, Barker LK, Thornton-Evans G, Eke PI, Beltrán-Aguilar ED, Horowitz AM, Li CH. Trends in oral health status: United States 1988-1994 and 1999-2004. Vital Health Stat 11 2007;248:1-92. 12. Federation Dentaire Internationale (FDI) World Health Organization (WHO), International Association for Dental Research (IADR) Joint Statement from the European Dental Caries Conference, 2006. 13. Peneva M. Rashkova, M., Doychinova. - Age distribution of caries lesions in children’s permanent teeth – a basis for the choice of a therapeutic solution, www. Imab-bg.org, 2007; 14. Petersen PE, Bourgeois D, Bratthall D, Ogawa H. Oral health information systems – towards measuring progress in oral health promotion and disease prevention. Bulletin of the World Health Organization 2005;83:686-93. 15. Petersen PE. The World Oral Health Report 2003: continuous improvement of oral health in the 21st century – the approach of the WHO Global Oral Health Programme. Community Dentistry and Oral Epidemiology 2003;31 Suppl 1:3-24. 16. ROBERT A. BAGRAMIAN, DDS, MPH, PHD, FRANKLIN GARCIA-GODOY, DDS, MS & ANTHONY R. VOLPE, DDS, MS The global increase in dental caries. A pending public health crisis, Am J Dent 2009;22:3-8. 28 17. United States Department of Health and Human Services (USDHHS).National Call to Action to Promote Oral Health. National Institute of Health, 2003. 18. United States Department of Health and Human Services (USDHHS).Oral Health in America: A Report of the Surgeon General. National Institute of Health, 2000. 19. Wang HY, Petersen PE, Bian JY, Zhang BX. The second national survey of oral health status of children and adults in China. Int Dent J2002;4:283290. 20. World Health Organization Report by the Secretariat, Oral Health Plan for Promotion and Integrated Disease Prevention, Sixtieth World Health Assembly, Provisional Agenda Item 12.9, March, 2007. 21. World Health Organization, Oral health surveys – basic methods. 4th edition. Geneva: 1997 22. World Health Organization, Global oral health data bank. Geneva, 2004. Address for correspondence: Maya Rashkova, Associate professor, DM Department of Children's dental medicine, Faculty of Dental medicine, MU-Sofia 1, St. G. Sofiiski Blvd, 1431 Sofia e-mail: mayarashkova@mail.bg 29 Paediatric dentistry Parental role in relationship dentist – child M.Georgieva1, M.Peneva2 SUMMARY Introduction:. Good communication between dentist, child and parent provides a basis for quality treatment.Parental role in this triangle is less clear although it seems to give a great part of existing child dental fear in last few years.Dentists face the challenge to treat children who have self-discipline problems and could not cope with new difficult situation such as dental treatment.Parents have unreal expectations for his child behaviour and great expectations for dentist who choose behaviour management strategy.The aim of this study is to investigate parental role for child dental fear.For this purpose 30 children at the age between 3-4 years old from kindergarden in Sofia were examined.Each child completed drawing test and questionnaire in order to determine their anxiety.Each parent completed a questionnaire for define their emotional intelligence and anxiety.Children were examined in dental office at the end and information about their cooperation were reported. For fearful parents who could not manage with anxiety and transfer it to a child is recommended to find out another relative or adult to accompany child. The relationship between dental fear and uncooperative behaviour of a child patient and his parents was confirmed and is the key to successful child behavior management. Key words: Behaviour, dental fear, parental anxiety 1 2 Assistant., Department of Pediatric Dental Medicine, FDM - MU Sofia Professor, D.M., Department of Child Dental Medicine, FDM - MU Sofia 34 Introduction Child oral health demands early visits in dental office and getting used to treatment. At the same time childhood is a period of emotional, personal and cognitive maturation which leads to distinct fear and anxiety (1,2,4,6). It is very easy to create a uncooperative behavior to dental office which makes difficult normal procedure (3,5,7 ,9 ,11). There are previous researches for children’s behavior determination in our country as well as different behavior management methods. But still there are no studies concerning direct mother influence over children’s behavior. During early childhood and preschool age the connection between mother and child is extremely stronger and she is responsible for his development and behavior to dental treatment (8, 10, 12). The aim of this study was to examine the relationship between mother’s behavior when educates children and its contribution to children’s dental fear. Material and methods The subjects were 42 children at the age between 4 and 5 years old in kindergarten in Sofia. According to their behavior in dental office children were divided into 4 groups using Frankl behavior rating scale – definitely positive, positive, negative, definitely negative. 1 definitely positive child and 3 definitely negative children were examined from the group. This is the reason for formation of only two groups from positive and from negative children. Mothers were asked to complete a questionnaire which consists of 22 questions in order to determine their education. 7 of these questions concern mother emotional intelligence, 6 questions define mother authority during educational process, 2 questions determine mothers attitude towards children dental health and the rest 7 questions concern surroundings, family background, number of children in family, person who raise the child and if the child is planned or unwanted. Children were asked 9 questions which are looking for the result from mother behavior concerning children’s behavior formation. Five of the questions are in reply to mother’s authority and another four are in response to mother’s love which child feels during childhood. Studying the results from questionnaire with mothers and children includes definition of numbers to each answer. Mothers who receive 22 points occupy favorable educational behavior, for emotional intelligence – 7 points, for lack of authority – 3 points. From the child’s inquiry for whole favorable influence – 9 points, when child does not fell his mother authority – 5 points. Family drawing test of V. Huls and J.Dileo was used in which interpersonal relationships are assessed by having the child draw a family or some other situation in which more than one person is present. The test gives the opportunity to see the world through child eyes, to find out his subjective opinion about the family, his relationship with family members and his place in the family. Results were analyzed using five aspects - favourable family surroundings, anxiety, family troubles, lack of selfesteem and hostility in family. Personality technique where anxiety acts as diagnosed component graphic technique "cactus" M.Pamfilova. The test used to study the emotionalpersonal sphere of the child. When conducting diagnostic examinee is given a sheet of paper of A4 format and a pencil. The child was given the opportunity to draw a cactus the he had imaged it without questions and additional explanations. The child was given enough time for drawing picture. In addition, take into account the specific indicators that are specific to this method asking questions: 1. Is the cactus wild or domestic? characterization of the "image of a cactus (wild, domestic, feminine, etc.) 2. Can you touch it? characterization of needles (size, location, number) 3. Does the cactus like taking care of it: to water, to fertilize? 4. Does the cactus live alone or with other plants? If the cactus is not alone or with what kind of neighbors it lives with? 5. When the cactus grows what will change in it? When the results are taken into account the data corresponding all graphical methods, namely: spatial position, image size, characteristics of lines, the force pressure on the pencil. 35 Results and discussion: Results of mother’s characteristic that best predicted children’s behaviour problems during education are presented in table №1. Average All the points σ answers Т, р children n number %+ + positive 24 17,5 1,64 79,5% 4,78 negative 18 14,8 1,98 67,1% р<0,001 Table 7: Mother’s behavior during child education It is clear from analyzing the whole mother’s behavior during child education that mothers of children with positive attitude towards dental treatment have average 17,5 positive points, while those with negative – 14,8. Difference between them is statistically reliable which proofs definitely the relationship between mother’s dental behavior and children’s dental behavior. Mothers of children with positive attitude to dental treatment positive answers are close to 80% , those with negative – under 70%. children n Average points number + σ % + All the answers children n Average points number + σ %+ All the answers Т, р positive 24 5,08 1,21 72,6% 2,27 negative 18 4,33 0,97 61,8% р<0,05 Table 9: Mother’s emotional intelligence Responses of mothers to 7 questions and their answers were used to determine emotional intelligence. Answers show the sincerity of mothers, optimism, concern of child’s problems, spending time with the child etc. The obtained results indicate that mothers with higher emotional intelligence reply positive children, while those with negative response to the manipulation have mothers with lower emotional intelligence. The difference is statistically significant although not very clear. children n Average points number + σ %+ All the answers Т, р positive 24 0,91 0,65 30,3% 2,9 negative 18 0,33 0,48 11% р<0,05 Т, р positive 24 6,66 1,34 74% 5,35 negative 18 5 0,68 55,5% р<0,001 Table 8: Mother’s behavior reflection on children Complete effect from mother’s behavior influence was found in the amount of all children’s answers. Positive children have average about 7 answers, which shows favorable mother’s influence from the whole 9 answers, while negative children have only 5 answers and the differences between them is statistically significant. Positive children have 74% positive points, while negative have a bit over 50%. This shows children’s dependence on mother’s behavior. Table 10: Mother’s authority during education According the authority in education results show that more mothers use this kind of education. Although there is a danger the survey questions to refer mothers to the right answer even it is not truthful, the ones which indicate imposing punishment in case of not keeping mother's orders were formed in pairs, so that the polite answer could be compared to the particular action.Mothers who educated children with strictness are very often irritated by disobedience and impose a punishment. Positive children have positive mother’s behavior only 30%, while negative only 11%. Here however there is a reliable difference and mothers of positive child are less authoritarian. 36 children n Average points number + σ %+ All the answers Т, р positive 24 2,75 1,39 55 % 4,78 negative 18 1,22 0,64 24,4% р<0,05 pressure on the pencil; family conflict expressed by stumbling block and space between figures; sense of inferiority expressed by author isolation from his mother; hostility in the family – deformed figures. Such an example is shown in the next figure №1. Table 11: Authoritarian behavior and emotional surroundings impact on children Authoritarian behavior of mothers has a reflection on children and this could be defined by their answers about mother’s punishment, emotional dependence of her, lack of self-dependence, maturity and tranquility. Positive children have 55% positive answers, while negative – only 24%. Difference is definite and statistically significant, which indicates the great importance of mother in forming independence and willingness to cope with new situation such as dental treatment. children n Average points number + σ %+ All the answers Т, р positive 24 2 0 100% 7,12 0,22 0,42 11% р<0,001 negative 18 Figure 1 In cooperative children with positive attitude to dental treatment predominate optimum and friendly surroundings, which could be founded in presenting of all family members, picture begin with a drawing of person, some family members absent, lines are well done. Such an example is shown in the next figure №2. Table 12: Mother’s behavior towards child oral health The relationship between mothers’ attitude towards child oral health and child behavior in a dental setting is strongly demonstrative. Cooperative children have parents who are anxious about their oral health in 100%. While only 11% of parents of uncooperative children have positive attitude. Mothers’ responses also showed contradiction and insincerity because they mentioned that children visit dental office regularly and have not behavior problems but children have such problems objectively. The influence of family environment and finding his place in it was determined by using a drawing test “My family”. Analysis shows that in negative children predominate anxiety expressed by strokes, the force Figure 2 Application of graphic technique "cactus” confirmed the results. Positive children show sincerity - prominent needles, leadership - picture with good proportions, filling the paper, optimism – expression of „ happy cactus”, extroversion – other cactus presence. Such an example is shown in the next figure №3. 37 Conclusions 1. Mother’s emotional intelligence helps formation of child positive behavior to dental treatment; 2. Authoritarian education in combination with punishment forms negative children; 3. Mother’s concern for child oral health creates cooperative behavior; 4. Solidarity and tenderness in the family create positive child behavior; 5. Conflicts in the family form negative child behavior. Figure 3 In negative children predominate aggression – long needles presence, reticence – zigzags drawing inside the figure, introversion – presence of only one cactus close to the end of the paper. An example is shown in the next figure №4 Figure 4 The obtained proofs show clearly that mother has a great influence on child behavior in dental office and plays a significant role in helping children to cope with dental treatment. Circumstances which form children as well-balanced, independent and ready to solve the problems or as closed, aggressive, uncertain and worried about every new situation are family surroundings, love in the family, mistakes intolerance, imposing punishment, affection need. The results give us confidence to continue and extend our study for standardization of parent behavior models in child raising and educating. Reference 1. Панфилова – Игротерапияобщения. Тесты и коррекционныеигры.Гном и д, 2008, 160. 2. American Academy of Pediatric Dentistry. Guidelines for behavior management of The American Academy of Pediatric Dentistry. Va Dent J 1994,71,20-25. 3. Arnrup K, Berggren U, Broberg AG. Attitudes to dental care among parents of uncooperative child dental patients. Eur J Oral Sic 2002, 110, 75-82. 4. Cardoso CL, Loureiro SR, Nelson-Filho P. Pediatric dental treatment: manifestation of stress in patients, mothers and dental school students. Braz Oral Res 2004, 18, 150-155. 5. Colares V, Richman L. Factors associated with uncooperative behavior by Brazilian preschool children in the dental office. ASDC J Dent Child 2002, 69, 87-91. 6. Dileo Joseph H. Interpreting children’s drawings.New York, Psychology Press, 1983, 234. 7. Huber M, Freeman R, Humphris G et al. Empirical evidence of the relationship between parental and child dental fear: a structured review and meta-analysis. Int J Pediatr Dent.2010, 20, 83-101. 8. Klingberg G, Berggren U, Carlsson SG, Noren JG. Child dental fear: cause –related factors and clinical effects. Eur J Oral Sci 1995, 103, 405-412. 9. Klingberg G, Lofqvist LV, Hwang CP. Validity of the children's dental fear picture test (CDFP). Eur J Oral Sci 1995, 103, 55-60. 10. Lara A, Grego A, Maroto M. Emotional contagion of dental fear to children: fathers' mediating role in parental transfer of fear. Int J PediatrDent 2011,10, 60-65. 38 11. Milgrom P, Mancl L, King B et al. Origins of childhood dental fear. Behaviour Research and Therapy 1995,33, 313-319. 12. Muris P, Steerneman P, Merckelbacw H. The role of parental fearfulness and modeling in children's fear.BehaviourResearch Therapy 1996, Vol. 34, No. 3, pp. 265-268. 13. Ten Berge M, Veerkamp JSJ, Hoogstraten J et al. Parental beliefs on the origin of child dental fear in the Netherlands. J Dent Child 2001, 68, 51-54. 14. Wigen TI, Skaret E, WangNJ. Dental avoidance behaviour in parent and child as risk indicators for caries in 5-year-old children.Int J Paediatr Dent. 2009 Nov;19(6):431-7. Address for correspondеnce: Professor Milena Peneva, D.M. Department of Pediatric Dental Medicine Faculty of Dental Medicine, MU-Sofia 1, St. G. Sofiiski Blvd, 1431 Sofia e-mail: milenapeneva@mail.bg 35 Paediatric dentistry The impact of the etching time upon the bond strength with the dentine in primary teeth - in vitro study N. Gateva1, R. Kabakchieva 2 SUMMARY Objective: The aim of this study was to investigate the influence of the etching on the bond strength of total etch adhesives used in primary tooth dentin. Methods: Flat dentin surfaces from 48 primary molars were divided in 4 groups. Two different total etch adhesive systems were used – one tree steps (OptiBond FL, Kerr) and one two steps (Exite, VivaDent). In half of the specimens, the recommended etching time was used 15 s, in the other half the etching time was reduced to 7 s. After applying the adhesive, resin composite build-ups were constructed by means of conventional copper ring and stored in water for 72 h at room temperature. Specimens were tested for macrotensile bond strength. Debonded surfaces were analyzed by SEM. Conclusion: Reducing the dentin etching time to 7s in primary teeth and using total etch adhesives improve macrotensile bond strength Key words: primary teeth, etching, bond strength, adhesive system 1 2 Assistant professor, Department of Pediatric Dentistry, Faculty of Dental Medicine, Sofia Assoc.Professor , Department of Pediatric Dentistry, Faculty of Dental Medicine, Sofia 36 Introduction Instructions for application of all adhesive systems still lack specific guidance for their application in the primary dentition. Their use in the restoration of deciduous teeth in everyday dental practice is transmitted from the permanent dentition, without taking into account the lack of recommendations by the manufacturers for application of a treatment protocol for primary teeth (5, 12, 16, 20, 27, 34, 38). Between the two dentition there are certain differences in terms of the structures that built them (15, 17, 27, 36, 38). These differences have an impact on the quality of adhesion, and their bond to the aesthetic restorative materials and hence on the durability of these restorations (17, 24, 25, 26, 32, 35, 38). The greater density of dentine tubules per unit area and the thicker peritubular dentine in deciduous teeth, reduce the amount of intertubular dentine, which is available to perform the bonding procedures (18, 22, 36). From a chemical point of view, the dentine of the primary teeth is more reactive to the effect of the acid conditioners, due to the lower degree of mineralisation of the tooth structure of the primary dentition (2, 14, 19, 24, 25, 32). SEM observations indicate the formation of a thicker hybrid layer in deciduous teeth compared to that in the permanent teeth after the same etching time (5, 24, 25, 32, 33, 36). Studies made on samples of primary teeth showed incomplete infiltration of the adhesive monomer in the spaces between the collagen fibers at the bottom of the demineralised area, leading to the formation of a zone of exposed collagen fibers at the bottom of the hybrid layer which compromises the adhesive bond (10, 24, 25, 30, 31, 32). This demineralised, non impregnated dentine at the bottom of the hybrid layer has been described as the most weak and vulnerable area at the dentin-adhesive border (10, 24, 25, 32). NN Etching time Group Group 1 37% phosph.etch gel – 15 s 10 Group 2 10 37% phosph.etch gel – 15 s Group 3 10 37% phosph.etch gel – 7 s Group 4 10 37% phosph.etch gel – 7 s Table 1: Grouping of the experimental samples Reducing the dentine etching time of primary teeth is offered as an opportunity to achieve adequate bond strength by forming a homogeneous hybrid layer (24, 25, 27, 33, 38). Due to the greater reactivity of the dentine of primary teeth to etchants, they can be applicated for a shorter time compared to that of permanent teeth. Moreover, there is no positive correlation described between hybrid layer thickness and bond strength (10, 30, 33). To determine the effectiveness of the adhesive systems, the most commonly used methods are SEM observation and bond strength tests (21, 27, 37). The aim of this study was to evaluate the impact of etching time on the primary teeth dentin bond strength and total-etch adhesives. - To achieve this aim the following tasks were set for completion: To assess the impact of the etching time - 7 and 15 s on the primary teeth dentine bond strength and application of total-etch adhesives; - To determine by SEM observation the type of destruction after the application of macrotensile bond strength test. Material and methods For the purposes of the study, 48 intact deciduous molars were used. The teeth were collected from healthy children, after an informed consent was signed by their parents for its use in the experiment. The teeth were extracted due to physiological changes or orthodontic indications. They were cleaned from the soft tissues, and the existing roots were removed. By the time when the experiment started, the teeth were stored in saline for no longer than three months. Grouping of the experimental samples. The teeth were randomly selected into 4 groups which are presented in Table 1. From each group 2 teeth were prepared for SEM observation of the dentine-adhesive zone. Adhesive system OptiBond FL (Kerr) – 3 steps-total etch Exite (Ivoclar,Vivadent) - 2 steps-total etch OptiBond FL (Kerr) – 3 steps-total etch Exite (Ivoclar,Vivadent) - 2 steps-total etch 37 Preparation of the dental surface. From the occlusal crown surface of all samples the enamel and part of the dentine were removed. Using round turbine burr (ISO 806 314 001534 012 for primary teeth) and water cooling, a medio-distal cut is made through the central occlusal fissure.The depth of the cut is compatible with the size of the burr. The depth of the enamel and dentine to be removed from the occlusal surface is marked in advance, which allows for removal of relatively compatible layer of enamel and dentine for each of the experimental samples. A cut parallel to the occlusal surface is done with highspeed burr (ISO 806204108524835010) and under water cooling. The cut is made up to the controlled depth determined by the initial cut with the round burr. The surface is smoothed with a polishing disc. This leads to the formation of a smooth dentine surface, which is at compatible distance from the central fissure. Samples are observed with optic microscope OLYMPUS VANOX-T under zoom 25x to 100x to establish whether the enamel has been completely removed from the occlusal surface. Making of the restoration. A copper rings (№15) with height 5 mm and diameter 5mm are used for the manufacture of comparable and predictable surfaces of the restoration. Factory-made standard copper rings are cut with the help of two-side diamond disks, in order to achieve the desired height. The etching was performed for 15 s in specimens from group 1 and 2 and for 7 s in those from group 3 and 4. The etching and application of the adhesive system (according to the manufacturer's instructions) was done centrally on the exposed dentine surface on an area with a diameter comparable to the copper ring. On the prepared dentine surface copper ring was placed. Within this ring is placed one layer light cure composite (Tetric EvoCeram, Ivoclar Vivadent, A3 shade) was placed with thickness up to 2 mm, which is polymerized with UV light for 40 s from a UV lamp (Coltolux 75, Curing Light, Coltène Whaledent). The next step consists of setting a metal loop of orthodontic wire (№0.8), perpendicular to the cut of the occlusal surface with a length of about 10mm in the center of the ring, and a fresh amount of composite, which stretches the metal ring and clamps the metal loop. Up next comes light polymerization for 40 s. The two free ends of every metal loop, which is placed in the copper ring and is covered with composite, are finished with retainer loop. From the side of the pulp chamber, on the level of the cut roots, the preparations of the specimens consists of etching of the entire pulp chamber for 15 s, washing – 15 s, air-drying and application of 3-steps adhesive system. A layer of composite is placed, along with light polymerization for 40 s. After that a second metal loop is being placed, aligned to the one, which is already on top of the occlusal surface in the metal ring. The final step is addition of composite untill the whole pulp chamber is filled, along with light polymerization for 40s. The prepared specimens are stored in water at room temperature for 72 hours, prior to the test. Testing the bond strength.The measurement of the achieved bond strength is conducted on stand for physical-mechanical examination type INSTRON – 1185. Metal loops similar to the ones built in the studied teeth are fixed rigidly in the standard grips of the machine and at the other end - hinged to the metal loops of the model. The loading bar is moving at a steady speed of 1 mm/min. The maximum force of resistance, causing debonding (in MPa) is registered. The test is terminated after the final destruction of the test specimen. Determining the type of destruction. After the macrotensile bond strength test specimens were dehydrated in ascending concentrations of ethanol 75%, 95% and 100% for 1 h in each concentration. After dehydration the samples were placed on the filter paper and covered with a glass lid for 24 h. Both halves of each specimen were observed in the SEM under 18 x to 1500 x magnification to determine the type of destruction. SEM observation allows more precise determination of the place of failure. The failure type for each sample is classified into one of the following types: Type 1: Adhesive failure mode – the fracture line is located in the adhesive layer of the border zone dentine – adhesive or composite – adhesive - this is a failure in the adhesion. Type 2: Cohesive failure mode - fracture line passes only within the composite. Type 3: Mixed failure mode - the specimens show both types of fracture - the adhesive and cohesive destruction - dentin-adhesive-composite. 38 Furthermore two teeth from each group, prepared in the same way described were cut perpendicular to the bonded surface to examine the morphology of the borderline surface between the adhesive system and dentine for the two different etching time - 7 and 15 s. The prepared samples are placed on an aluminium discs. They are then covered in vacuum with golden powder in a media of argon-cathode atomization with JEOL JFC – 1200 Fine coater. The research was carried out with scanning electron microscope type JEOL JSM – 5510 SEM with 750x zoom. Results and discussion Our study evaluated the impact of etching time on the dentine bond strength of deciduous teeth after application of total etch adhesive systems. Table 2 presents the measured average bond strength after recommended (15 s) and shortened etching time for 7 s with 37% phosphoric acid and application of total etch adhesives. N Adhesive Etching Macrotensile bond strength (МРа) Group system time mean ± SD Minimum Maximum group 1 10 OptiBond FL 15 s 12,68±0.52 9,72 14,87 group 2 10 Exite 15 s 10,24±0.31 8,87 12,02 group 3 10 OptiBond FL 7s 16,00±0.87 10,78 21,66 group 4 10 Exite 7s 15,48±0.87 11,60 18,97 Table 13: Bond strength in primary teeth and total etch adhesives When comparing the mean of the bond strength in specimens that were etched for 15 s (Table 2, groups 1 and 2) with the ones etched for 7 s (table 2, groups 3 and 4), the results show that the etching time influences the registered mean values of the bond strength in total etch adhesive systems. The reduction of the etching time up to 7 s (group 3-16,00 MPa and group 4 – 15,48 MPa,table 2) leads to increased mean values of the bond strength compared to those in specimens etched for 15 s (group 1-12,68 MPa and group 2 – 10,24Mpa, table. 2). These differences are statistically significant for both adhesive systems considering the bigger bond strength and the shorter etching time (tabl. 3). The relation between the type of the adhesive system and the bond strength is an object of another study performed by us. Group N Group 1 Group 3 Group 2 Group 4 10 10 10 10 Bond strength(МРа) mean ±SE 12.68±0.52 16.00±0.87 10.24±0.31 15.48±0.87 Т Р 3.26 <0.01* 5.65 <0.0001* *The difference is statistically significant Table 3: Bond strength in primary teeth etched for 7 and 15 s. The results from the observations with SEM to determine the type of the destruction are presented in Table 4. Adhesive Cohesive Mixed failure failure mode failure mode mode N % N % N % Total etch Group 1 7 70.0 0 0.0 3 30.0 adhesives Group 2 9 90.0 0 0.0 1 10.0 Mean 16 80.0 0 0.0 4 20.0 Group 3 3 30.0 1 10.0 6 60.0 Group 4 3 30.0 2 20.0 5 50.0 Mean 6 30.0 3 15.0 11 55.0 Table 4: Distrubution according to the failure mode in primary teeth specimens and total systems for 15 s and 7 s. Total Group N % 10 100 10 100 20 100 10 100 10 100 20 100 etch adhesive 39 The reduction of the etching time (group 3 and 4) leads to decreased adhesive failure mode in primary teeth from 80 % to 30 % and increased cohesive and mixed failure mode (table. 4) We performed SEM observation of the border zone dentine-adhesive system. A B Figure 1: SEM of hybrid (between the arrows) and adhesive (AD) layer within the dentine borders in a primary molar, etched with 37 % phosphoric acid for 15 s (fig.1A) and 7 s. (fig. 1 B) and adhesive system OptiBond FL (three step system). Multiple adhesive resins (R) and microcracks (fig.1A-thumb) are visible within the dentine (D); C=composite. A B Figure 2: SEM of hybrid (between the arrows) and adhesive (AD) layer within the dentine borders in a primary molar, etched with 37 % phosphoric acid for 15 s (fig.2A) and 7 s. (fig.2B) and adhesive system Exite (two step system). Multiple adhesive resins (R) and microcracks (fig.2A-thumb) are visible within the dentine (D); C=composite. Fig. 1 and fig. 2 show the border zone dentineadhesive, after the application of the two generation adhesive systems (optiBond and Exite) and different etching time (15 s and 7 s). The etching time of 15 s leads to formation of a thicker hybrid layer with both adhesive systems. The comparison of the photos of the specimens from group 1 with those from group 3 (fig. 1 A and B) and the specimens from group 2 and 4 (fig. 2 A and B) shows the formation of a thicker hybrid layer with the presence of microcracks in the specimens etched for 15 s (Fig. 1 A and fig. 2Athumb) at the border between the adhesive and hybrid layers, as well as inside the hybrid layer. To achieve effective bonding to the dentine, the applied adhesive system should form a hybrid layer as a result of the infiltration of the adhesive monomers between the organic components – the collagen fibers of the dentine (8, 23, 29). The quality of the hybrid layer depends on the pH of the etching agent, the 40 ability of the resin monomers to infiltrate the demineralized dentine and the specific properties of the dentine substrate (3, 6, 7, 8, 20, 27, 33, 36). The bonding is stable if the etching agent has been infiltrated completely by the adhesive and the different levels of incomplete impregnation have been avoided (9, 31, 38). The bond strength with the dentine depends significantly on the properties/ quality of the formed hybrid layer, but not on its thickness, that means that thicker hybrid layer doesn’t contribute to better adhesive bond strength (5, 9, 11, 24, 25, 28). In our experiment, the reduction of the etching time up to 7 s, showed higher values of the bond strength compare to the groups in which the teeth were etched for 15 s with the two types of adhesives (Tabl. 3). These differences are statistically significant (p<0.05). SEM analysis showed the formation of significantly thicker hybrid layer after etching for 15 s (fig.1A and fig.2A), compared to that formed after etching of the specimens for 7 s (fig.1B and fig.2B). These results correspond to the results reported from other researchers and confirm that there is a lack of positive correlation between the thickness of the hybrid layer and the bond strength (10, 30, 32). Although, the hybrid layer formed after 15 s etching is almost twice thicker for both adhesive systems, the bond strength is less compared to that in specimens etched for 7 s. (Tabl. 3). The results from another research done by us showed that etching for 7 s with 37 % phosphoric acid leads to formation of the dentine surface clean from the smear layer and precipitates (1). The primary teeth dentine is less mineralized than that of the permanent teeth (13, 14, 19). Therefore, it has reduced buffer capacity towards acids used for etching (14, 19, 32). If the etching time is increased that leads to deeper demineralization of intertubular dentine and formation of thicker hybrid layer in primary teeth. The possibility that deeply demineralized dentine to be incompletely impregnated by the adhesive system leads to the risk of formation of a zone not infiltrated with adhesive between the hybrid layer and the intact dentine structure. That zone remains less resistant at the bottom of the hybrid layer and could be a possible path for micro- and nanoleakages, enzymatic and hydrolytic degradation, and in general a point for a bond failure (10, 24, 25, 31, 32). The reason for this is probably the microcracks observed by us in specimens from groups 1 and 2, that have been etched for 15 s. (Fig. 1A and 2 A thumb) The SEM observation that we conducted to determine the type of the failure after the macrotensile test was performed showed that the redusing of the etching time up to 7 s within the dentine with totaletch adhesive systems results in decreased percentage of the adhesive failure mode and increased cohesive and mixed failure mode in primary teeth (the adhesive failure mode decreases from 80 % to 30 % - table 4). These correspond to the results observed from the macrotensile test (tabl. 3). In other words, if the values of the bond strength are higher, it is more likely to have cohesive or mixed failure mode. (4, 34). This in vitro study showed that the reduction of the etching time up to 7 s within the dentine in primary teeth plays significant effect on the bond strength when the total etch adhesives are applied. The reduced etching time, results not only in higher bond strength values, but is a prerequisite for formation of a hybrid layer which is significantly more resistant to destruction. Conclusions 1. In primary teeth the reduction of the etching time within the dentine up to 7 s results to increased values of the registered bond strength compared to that after 15s etching time and the application of total etch adhesives. 2. In primary teeth the thickness of the formed hybrid layer increases if the etching time is longer. 3. The thicker hybrid layer is not a guarantee for a better mechanical bond strength. Reference 1. Гатева Н.: Сравнителни СЕМ изследвания на промените по повърхността на дентина при временни и постоянни зъби след ецване. Проблеми на денталната медицина, том XXXIV / 2008, част 1, стр.71 – 84 41 2. Angker I., Swain MV., Kilpatric N.: Micromechanical characterization of the Properties of Primary Tooth Dentine.: J Dent 2003; 31: 261-267 3. Breschi L. et al.: Dental adhesion review: Aging and stability of the bonded interface Dent Mater 2008; 24: 90–101 4. Can-Karabulut D. et al: Adhesion to primary and permanent dentin and simple model approach. Eur J Dent 2009; 3: 32-41 5. Carmona VB. et al.: Effects of Etching Time of Primary Dentin on Interface Morphology and Microtensile Bond Strength. Dental Materials 22, 2006; №12: 1121-1129. 6. Cetingüc A., Olmez S., Vural N.: HEMA diffusion from dentin bonding agents through various dentin thickness in primary molars. Am J Dent 2006; 19: 231–235. 7. De Munck J. et al.: A critical review of the durability of adhesion to tooth tissue: methods and results. J Dent Res 64, 2005; №2: 118-132 8. Eick JD. et al.: Current Concepts on Adhesion to Dentin. Crit Rev Oral Biol Med 8, 1997; №3: 306335 9. El Kalla IH, Garcia-Godoy F.: Bond strength and interfacial micromorphology of four adhesive systems in primary and permanent molars. J Dent Child 1998; 65: 169–176. 10. Hashimoto M. еt al.: The Effect of Hybrid Layer Thickness on Bond Strength: Demineralized Zone of Hybrid Layer. Dent Mater 2000; 16: 406-411 11. Hashimoto M. et al.: Over-etching Effects on Micro-tensile Bond Strength and Failure Patterns for Two Dentin Bonding Systems. J Dent 2002; 30: 99105 12. Hosoya Y.: Hardness and elasticity of bonded carious and sound primary tooth dentin. J Dent 2006; 34: 164–171 13. Hosoya Y., Marshall GW.: The NanoHardness and Elastic Modulus of Sound Deciduous Canine Dentin and Young Premolar Dentin – Preliminary Study. J Mat Scie: Mat Med 16, 2005; № 1: 1-8 14. Hosoya Y. et al.: Microhardness of Carious Deciduous Dentine. Oper Dent 2000; 25: 81-89 15. Johnson DC.: Comparison of Primary and Permanent Teeth 11. In Oral Development and Hystology. Avery JA. Editor – BC-Decker Philadelphia 1988, pp.180-190 16. Kaaden Ch., Schmalz G., Powers JM.: Morphological Characterization of the Resin-Dentin Interface in Primary Teeth. Clinic Oral Invest 7, 2003; № 4: 235-240 17. Koutsi V. et al.: The effect of Dentin Depth on the Permeability and Ultrastructure of Primary Molars. Pediatr Dent 1994;16: 29-35 18. Lopez GC. et al.: Dental adhesion: Present state of the art and future perspectives. Quint Int 2002; 33: 213-224 19. Mahoney E. et al.: The Hardess and Modulus of Elasticity of Primary Molar Teeth: an Ultramicroindentation Study. J Dent 2000; 28: 589594 20. Marquezan M. et al.: Microtensile Bond Strength of Contemporary Adhesives to Primary Enamel and Dentin. J Clin Pediatr Dent 32, 2007; № 2: 127–132 21. Marshall GW. et al.: Demineralization of caries-affected transparent dentin by citric acid: and atomic force microscopy study. Dent Mater 2001; 17: 45–52. 22. Marshall GWJr. et al.: The Dentin Substrate: Structure and Properties Related to Bonding. J Dent 25, 1997; № 6: 441-458 23. Nakabayashi N., Kojima K., Masuhara E.: The promotion of adhesion by the infiltration of monomers into tooth substrates. J Biomed Res 1982; 16: 265-273 24. Nör JE. et al.: Dentin Bonding: SEM Comparison of the Resin-Dentin Interface in Primary and Permanent Teeth. J Dent Res 74, 1996; № 6: 1396- 1403 25. Nör JE. et al.: Dentin Bonding: SEM Comparison of the Dentin Surface in Primary and Permanent Teeth. Ped Dent 19, 1997; № 4; 246-252 26. Olmez A. et al.: Comparison of the resin dentin interface in primary and permanent teeth. J Clin Pediatr Dent 1998; 22: 293-298. 27. Osorio R. et al.: Primary dentin etching time, bond strength and ultra-structure characterization of dentin surfaces. J Dent 2010; 38: 222-231 28. Perdigão J., Lopes M.: The Effect of Etching Time on Dentin Demineralization. Quintessence Int 2001; 32: 19-26 29. Perdigão J: Dentin bonding—Variables related to the clinical situation and the substrate treatment. Dent Mater 26, 2010; № 2: 24-37. 30. Pioch T., et al.: Influence of different etching times on hybrid layer formation and tensile bond strength. Am J Dent 1998; 11: 202–206. 42 31. Sano H., et al.: Microporous Dentin Zone Beneath Resin-Impregnated Layer. Oper Dent 19, 1994; № 2: 59-64 32. Sardella TN., et al.: Shortening of Primary Dentin Etching Time and its Implication on Bond Strength. J Dent 2005; 33: 355-362 33. Shashikiran ND., et al.: Comparison of ResinDentin Interface in Primary and Permanent Teeth for Three Different Durations of Dentin Etching. J Indian Soc Pedo Prev Dent 20, 2002; № 4: 124-131 34. Soares FZ. et al.: Microtensile bond strength of different adhesive systems to primary and permanent dentin. Pediatr Dent 2005; 27: 457–462 35. Stalin A., Varma B., Jayanthi.: Comparative Evaluation of Tensile-Bond Strength, Fracture Mode and Microleakage of Fifth, and Sixth Generation Adhesive Systems in Primary Dentition. J Indian Soc Pedod Prev Dent 2005; June: 83-88 36. Sumikava DA., еt al.: Microstructure of Primary Tooth Dentin. Ped Dent 21, 1999; № 7: 439444 37. Toledano M. et al.: Microtensile bond strength of several adhesive systems to different dentin depths. Am J Dent 2003; 16: 292–298. 38. Torres CP., et al.: Tensile Bond Strength To Primary Dentin After Different Etching Times J Dent Child 2007; 74: 113-117 Adress for correspondence: Gateva Natalia Faculty of Dental Medicine, MU-Sofia 1, St. G. Sofiiski Blvd, 1431 Sofia e-mail: nataliagateva@yahoo.de 43 Prosthetic dentistry The “Sofia” Chewing Simulator – construction, working principle and possible applications of the device – I part I.Ivanov 1, I.Chakalov 2 SUMMARY Objective: The main objective of the present work is the creation of a chewing simulator – a device reproducing in a laboratory the main parameters of the chewing cycle. Materials and methods: The chewing simulator was designed on a “Solid Works” software, allowing for planning, visualization, and motion simulation of all the components of the device long before it was created. The original construction principle of the chewing simulator, designed in order to obtain a dynamic force curve of the chewing cycle, was the application of magnetic field generated by a permanent magnet and a rotating laser-cut cam made of a ferromagnetic material. The variation in the distance between the cam and the magnet added to the permanent force generated by a lever and a constant load shape the force profile of the device. Results: The construction principle and schemas of the chewing simulator are presented. Conclusion: The chewing simulator is able to reproduce the main mechanical characteristics of the chewing cycle. Among the various possible application of the device is worth mentioning: various researches of the wear resistance of dental materials, studies of adhesion and micro-leakage, abrasiveness of toothbrushes and toothpastes. 1 Dipl. Eng. 2 Assistant professor, Department of Prosthetic Dentistry, Faculty of Dental Medicine – Sofia. 44 Introduction The data regarding the wear resistance of dental materials is an important characteristic of all restorative materials used in dentistry. In our previous publication (1) we presented the desired working parameters of a chewing simulation device based on the characteristics of the existing chewing simulators created in different universities and research centers throughout the world, as well as on the recent studies of the chewing cycle which explain this process in a different way. The experiment should allow us to reproduce: an area of abrasion (three-body wear) and an area of attrition (two-body wear). In order to reproduce the first type of wear most authors use loads of 20N and different artificial food media, while for the second type the different research teams use different loads, the most often cited in literature being devices using loads of 50N. The simulated chewing should be able to reproduce the stages of the chewing cycle and the corresponding dynamic loading curve. - Initial contact between the teeth with a definite small load (occurring during normal occlusion between the vestibular cusps of the upper and the lower teeth) - Sliding of teeth to the position of central occlusion (accompanied with an increase in the loading force and reaching its maximum values) - Stage of grinding of the food occurring between the functional cusps of the upper and the lower teeth (according to the occlusal theory by Le Gall (2). The values of the loading force remain comparatively high but lower than the maximum values. An important characteristic of the chewing simulator is the possibility to carry out the experiments both in water and in an artificial food medium. Other chewing simulation devices also possess such a feature, for instance those created in the Universities of Oregon and Bordeaux – UVSB2 (3) and OSHU (4). Another important factor for making the simulation similar to the real process of chewing is the separation of the tested specimens at the end of each cycle, which allows the artificial food to enter between the tested surfaces. Such a feature possesses, for example, the simulator of the University in Poznan (5). The possibilities for programming and adjustment of the contact time, the speed, the distance between the specimens and the length of the sliding path allow a wide range of experiments tobe carried out by the device. The exact values of these parameters have been discussed in detail in a previous publication (1). These are among the most significant parameters of the chewing simulator (6). It is considered an advantage if the chewing simulator can work both with antagonists made of natural tooth cusps (standardized – such as those used in the OSHU simulator (4) or non-standardized – used in the simulator of the Zurich University (7)) and with standard antagonists (most often made of ceramic materials with a definite hardness and shape (8)). The parallel testing of several specimens in several chambers of the chewing simulator reduces the time of the experiment and the variation in the results (9). From a technical viewpoint an important characteristic of the device is the automatic control of the completed and the remaining cycles and an automatic turn-off after all cycles have been completed. In our opinion one of the most important characteristics of the simulator is its flexibility – the constructionally determined possibility for quick and easy change of each of the above parameters. The aim of the scientific research is the creation of an original chewing simulator which meets all the above mentioned requirements. Material and methods Construction and working principle of the chewing simulator In collaboration with the engineers Ivan Ivanov and Hristo Angelov (working for the Sintcom company) who were responsible for the technical construction of the device, we developed the following cyclogram describing the desired mode of work of the device during the simulation of the chewing cycle. 45 Figure 1: A cyclogram presenting the movement of the antagonist against the tested specimen (upper curve), the change of the speed (the middle curve) and the load profile during one chewing cycle (lower curve). On the cyclogram (fig.1) the following parameters are presented: the movement of the antagonist in two axes during one chewing cycle (the uppermost curve – in the first portion the antagonist has descended and is in contact with the specimen while in the second portion it has separated from the specimen, as required by the task assignment). The second curve presents the change in the sliding speed of the antagonist along the surface of the specimen (the middle curve). The lowermost curve in fig.1 represents the change of the loading force of the antagonist while moving along the surface of the specimen. The three parameters change synchronously during one simulated chewing cycle. In this way the programmed loading curve meets both the requirement for separate zones of simulation of abrasion and attrition and the requirement for simulation of the three stages of the chewing cycle as described above. The type of movement is – reciprocating movement (unidirectional sliding) of the specimen (and) the antagonist along a closed rectangular trajectory/cycle which is composed of four phases: 1. Descending of the antagonist towards the specimen (closing) which reproduces the initial contact between the vestibular cusps of the antagonist teeth during the chewing cycle. 2. Sliding between the specimen and the antagonist accompanied by an increase in the loading force between the two elements (this corresponds to the loading curve and the sliding from the point of initial contact to the position of central occlusion. As it has been explained, in the position of CO the load reached its maximum value). According to the functional occlusal concepts developed by Prof. LeGall this stage is followed by sliding of the teeth during the “Cycle out” under a loading force lower than the maximum (2). Many studies on mastication and the chewing cycle, which were cited and discussed in our previous publication (1), have given evidence of such a contact. Figure 2: Schematic presentation of the working cycle of the antagonist according to the above cyclogram. The antagonist slides along a standardized specimen made of the tested material. 3. Opening – separation of the antagonist from the specimen (it corresponds to the end of the occlusal stage of the chewing cycle) 4. Return of the system in a starting position (corresponds to the preparation of the dentition for a new occlusal stage) The working parameters of the device have been set as follows: - Length of the sliding path – 7mm - Maximum distance between the specimens – 2mm - Average descending speed – 2,55 – 51 mm/sec - Average speed of separation – 2,60 – 52 mm/sec - Average sliding speed – 1,4 – 28 mm/sec - Average speed of reverse movement – 1,4 – 28 mm/sec - Loading force – 0-70N 46 - Change of the loading force during the sliding motion –0 – 30N - Number of cycles – 1 – 1 000 000 - Frequency – 0,1 – 2Hz - Number of specimens tested simultaneously/ Number of testing chambers – 4 - Power supply – 220V After setting the above parameters we continued with the conceptual development of a construction project. The device was designed by engineer Ivan Ivanov on the “Solid Works” software program. A carriage - 2 containing the tested specimens is mounted on the base (fig.3) of the simulator. Each specimen is made of the tested material which is cured/sintered in a metal ring according to the manufacturer’s instructions. Its surface is then polished and the specimen is secured in a tray, which is fixed on the mobile carriage - 2.Through a driving crank the latter is connected with the driving unit – 3.Using a cam system and an eccentric bushing, the driving unit puts in synchronous motion both the carriage and the yoke – 4. The antagonist is fixed to the yoke by a holder. The system for automatic control includes an inductive transducer – 5, which transmits impulses to a counter controlling the number of test cycles. The figure represents only the yoke, the load and the cam block of chamber1. In the real simulator these details are 4 – one for each of the tested specimens which are visible in the tray on fig.3. Figure 3: Simplified scheme of the chewing simulator and its main components: 1 – base, 2 – carriage, 3 – driving unit, 4 – yoke, 5 – inductive transducer Figure 4: Schematic view of the chewing simulator (a side view). On the figure are presented: the carriage consisting of: a soleplate – 6; linear ball bushings –7; cylindrical guides – 8; consoles – 9; tray – 10; the specimens – 16; the clamps – 11, the rocker – 13; the drawbar – 12; the eccentric bushing - 15 Fig.4 represents a side view of the machine. The carriage shown on fig.3 consists of a soleplate 6 which through linear ball bushings - 7, cylindrical guides – 8 and consoles – 9 is precisely fixed to the base of the simulator. The tray – 10, in which the specimens - 16 are fixed, is positioned on the carriage. The tray can be moved in a canal in the base – 6 and is fixed to the base by clamps – 11.This allows several experiments to be carried out on one specimen, as the tray can be moved and fixed in different positions perpendicularly 47 to the plane on fig. 4. Through the driving unit the carriage is connected to the rocker – 13. The rocker is also hinged to the drawbar – 12 of the carriage. The carriage is connected to the spindle of the driving unit through an eccentric bushing – 15. Thus the length of the sliding movement of the carriage is calculated as the double value of the eccentricity of the eccentric bushing – in this case 3,5mm. This allows for an easy alteration of the sliding path of the specimen and the antagonist, corresponding to the length of the contact between the antagonist teeth during the chewing cycle. Conclusion The described chewing simulator reproduces the desired mechanical parameters and the load profile of the chewing cycle. Reference 1. Chakalov I. Analysis of the characteristics of the chewing process. Rationale for the parameters and principles of the in vitro chewing simulator. Problems of dental medicine vol. XXXVI/2010 part II; p.69-80. 2. Le Gall MG, Lauret JF: Occlusion et function, uneapprochecliniquerationnelle, CdP Editions 2002. 3. Lasserre JF. Thèse pour le Doctorat d’Universite de Bordeaux2. Mention Sciences Biologiques et Médicales. Option Sciences Odontologique. Recherches sur l'usure dentaire et évaluation "in-vitro" de biomateriaux restaurateurs avec le simulateur d'usure UVSB2. 2003. 4. Condon J.R, Ferracane J.L. Evaluation of seven commercial composites using new in vitro wear simulator. Dent Mater 1996; (7); 12:218-226. 5. Koczorowski R, Wloch S. Evaluation of wear of selected prosthetic materials in contact with enamel and dentin. J Prosthet Dent. 1999; 81(4):453-459 6. Heintze SD: How to qualify and validate wear simulation devices and methods. Dent Mater. 2006 (8);22(8):712-34. 7. Krejci I, Lutz F, Reimer M. Wear of CAD/CAM ceramic inlays: restorations, opposing cusps, and luting cements. Quintessence International, 1994; 25:199-207 8. Shortall AC, Xiao QH, Marquis PM Potential countersample materials for in vitro simulation wear testing. Dent Mater 2002; 18 246-254. 9. Söderholm KJM, Lambrechts P, Sarret D, Abe Y , Yang MCK , Labella R ,Yildiz E, Willems G. Clinical wear performance of eight experimental dental composites over three years determined by two measuring methods. Eur J Oral Sci 2001:109:273-281 Address for correspondence: Chakalov I. Department of Prosthetic Dentistry, Faculty of Dental medicine , MU-Sofia 1, St. G. Sofiiski Blvd, 1431 Sofia 48 Prosthetic dentistry Construction of the “Sofia” chewing simulator. Basic modules, principle of functioning and possible applications. – Part II I. Ivanov 1 I. Chakalov 2 SUMMARY Objective: Part II of this paper presents the basic modules, the principle of functioning and possible applications of the “Sofia” chewing simulator. Material and methods: The chewing simulator was designed on the “Solid Works” software, allowing for planning, visualization, and motion simulation of all the components of the device long before it was created. The original construction principle of the device, designed to obtain a dynamic force curve of the physiological chewing cycle, was the application of magnetic field generated by a permanent magnet and a rotating laser-cut cam made of a ferromagnetic material. The variation in the distance between the cam and the magnet in addition to the permanent force generated by a lever and a constant load, result in the dynamic force profile of the device. Results: Part II of the paper presents the schemas of the basic modules, the way of functioning and the researches made possible with the use of the “Sofia” chewing simulator. Conclusion: The chewing simulator is able to reproduce the main mechanical characteristics of the physiological chewing cycle. Among the various possible application of the device is worth mentioning: various researches of the wear resistance of dental materials, studies of adhesion and micro-leakage, abrasiveness of toothbrushes and toothpastes. 1 2 dipl.eng. – Assistant professor, Department of Prosthetic Dentistry, Faculty of Dental Medicine – Sofia. 49 Introduction Part I of this publication presented the mechanical parameters of the physiological chewing cycle which served as a basis for the development and construction of the “Sofia” chewing simulator. The original construction principle, the dynamic load profile and several schemes of the device were also presented. Purpose Part II of the publication presents a detailed schematic view of the basic modules of the machine, as well as its working principle and possible applications. Material and methods The chewing simulator was first designed and constructed on the “Solid Works” software. The unique aspect in its design is the creation of a dynamic load profile similar to that of the physiological chewing cycle. It is obtained through the application of a magnetic field generated by a constant magnet and a rotating laser-cut cam made of a ferromagnetic material. The variation in the distance between the magnet and the cam in addition to the force generated by a lever and a constant load, result in the dynamic load profile of the device. Results The basic modules in the construction of the chewing simulator are the driving unit, the cam block, the yoke, the capsule holder with the antagonist and the magnet block. The driving unit consists of a spindle – 21 on which the cam block – 18, the eccentric bushing – 19 and the disk wheel – 20 are fixed. The spindle is put to motion by a self-aligning coupling -17 driven by a reductor motor (“Maxcon” 148867 PGL U). The driving unit is mounted on the base of the chewing simulator. Figure 5: Schematic view of the driving unit of the machine Figure 6: Schematic view of the cam block of the machine The cam block consists of the supporting bushing – 34 on which the lifter cam – 35 (allowing separation of the antagonist and the tested specimen at a precise moment of the chewing cycle) and the anchor – 37 are mounted. The anchor is made of a ferromagnetic material which interacts with the constant magnet fixed on the yoke (presented in more detail on the next scheme). The specific profile of the anchor is laser-cut and serves to obtain a variable force due to the variating distance between its periphery and the magnet block – 28 (presented on fig.9).The figure represents: the capsule holder with the antagonist tooth/sphere – 27; unit containing the capsule holder – 24, holder of the magnet block – 25, back roller – 29; constant load – 28; arm of the yoke – 22; bracket – 21. The elements presented on fig. 7 are mounted on the 50 arm of the yoke – 22 and the position of each element on the arm can be independently adjusted. This allows for the adjustment of the load by changing the length of the lever arm. The arm of the yoke is hinged to the bracket – 21, which is fixed to the base of the chewing simulator. Figure 7: Presents the construction of the capsule holder with the antagonist Figure 8: Presents the construction of holder of the capsule with the antagonist Fig. 8 represents: the antoagnist – 27 (it can be a tooth cusp, natural enamel or as shown on the figure – standard antagonist made of ceramic material), a capsule holding the antagonist – 30, fixing screws – 31 and – 32 which serve to fix the capsule at a definite height. The magnet block – 25 contains constant Neodimic magnets (generating together with the anchor – 37, fig. 6, the dynamic load profile of the chewing cycle). The magnet holder contains a back roller - 29 which slides along the lifter cam – 35, fig. 6, and is responsible for the separation of the antagonist and the specimen at the end of each chewing cycle. Working principle of the chewing simulator The spindle of the driving unit (fig. 5) creates a rotating movement which is transformed into a reciprocating movement by the rocker (presented in part I). In this way the carriage (fig. 3, part I) containing the specimens begins a reciprocating movement with a length of the driving path equal to the doubled eccentricity of the eccentric bushing – 19 (fig.5). At the same time the lifter cam ( - 35, fig. 6) mounted on the same spindle periodically lifts or drops the arm of the yoke, so when the specimen moves towards the driving unit the antagonist slides along its surface (sliding path). When the carriage moves in the opposite direction the lifter cam and the back roller have separated the antagonist from the surface of the specimen (backward motion). During the stages of the chewing cycle corresponding to the transitional parts of the lifter cam, a gradual ascending or descending of the antagonist towards the surface of the specimen is carried out. During the sliding of the antagonist along the specimen surface, the normal loading force is a sum of the constant force, determined by the load and the lever arm (fig. 1, part I) and the variable force obtained by the variation in the distance between the rotating ferromagnetic anchor (- 37, fig. 6) and the block of constant Neodimic magnets (- 28, fig. 9) attached to the rocker (presented with all its componentson fig. 7). This working principle featuring the desired parameters from the cyclogram on fig. 1, part I, is a result of the synchronous action of the three basic components – the eccentric bushing – 19, the lifter cam – 35 and the anchor – 37. The vertical movements of the antagonist – its ascending and descending towards the specimen, are carried out during the transitional stages, when the roller moves along the transitional parts of the lifter cam. These stages take up from the actual length of the sliding path and that is why their duration is as short as possible, following the principle of “minimum acceleration” during the ascending and the descending of the sphere towards the specimen. The normal friction load of the antagonist on the surface of the specimen changes during the sliding path, as it is shown on the lower curve on the cyclogram (fig. 1, part I). The starting and the final values of the load are reached predominantly during the transitional stages of descending and separation of the sphere from the specimen. On the cyclogram (fig. 1, part I) this curve is presented as a broken line and this is only a 51 schematic representation while the real process includes a gradual transition between the different segments. The cyclogram on fig. 1, part I, graphically represents the work of the simulator during the testing of different dental restorative materials used in the daily practice. The device possesses a functional flexibility which allows different (and practically unlimited) load interactions between the antagonist and the specimen to be obtained, depending on the specific needs of the experiment. Possible application of the “Sofia” chewing simulator The chewing simulator allows the change of different parameters, construction elements and the alteration of the conditions during the simulated chewing act. This gives possibilities for numerous scientific experiments to be carried out not only on the problem of wear but also on microleakage, adhesion, surface roughness, toothbrush and dentifrice abrasion. Some of the possibilities for scientific research are: • Studying the influence of the maximum loading on the tested surface and the wear mechanisms induced • Studying the influence of different, dynamically changing load profiles on wear • Studies with different materials used as antagonists - standardized/non-standardized enamel, different standard or custom-made ceramic materials • Abrasiveness of new materials on tooth enamel • Studying the influence of the sliding path – how the occlusion is related to the degree of wear of the dentition • Studies of the influence of different (food) medium on wear • Studies comparing the action of the different wear mechanisms • Studies of the wear caused by different toothbrushes and toothpastes • Cyclic loading and studying the materials’ fatigue, adhesion and microleakage Conclusion The chewing simulator reproduces the basic mechanical parameters of the chewing cycle and gives many possibilities for scientific research. From the numerous possible applications of the machine worth mentioning are: various experiments on the wear resistance of dental materials, studies of adhesion and microleakage, studies of toothbrush/dentifrice abrasion. Reference 1. Chakalov I. Analysis of the characteristics of the chewing process. Rationale for the parameters and principles of the in vitro chewing simulator. Problems of dental medicine vol. XXXVI/2010 part II; p.69-80. 2. Le Gall MG, Lauret JF: Occlusion et function, une approche Clinique rationnelle, CdP Editions 2002. 3. Lasserre JF. Thèse pour le Doctorat d’Universite de Bordeaux2. Mention Sciences Biologiques et Médicales. Option Sciences Odontologique. Recherches sur l'usure dentaire et évaluation "in-vitro" de biomateriaux restaurateurs avec le simulateur d'usure UVSB2. 2003. 4. Condon J.R, Ferracane J.L. Evaluation of seven commercial composites using new in vitro wear simulator. Dent Mater 1996; (7); 12:218-226. 5. Koczorowski R, Wloch S. Evaluation of wear of selected prosthetic materials in contact with enamel and dentin. J Prosthet Dent. 1999; 81(4):453-459 6. Heintze SD: How to qualify and validate wear simulation devices and methods. Dent Mater. 2006 (8);22(8):712-34. 7. Krejci I, Lutz F, Reimer M. Wear of CAD/CAM ceramic inlays: restorations, opposing cusps, and luting cements. Quintessence International, 1994; 25:199-207 8. Shortall AC, Xiao QH, Marquis PM Potential countersample materials for in vitro simulation wear testing. Dent Mater 2002; 18 246-254. 9. Söderholm KJM, Lambrechts P, Sarret D, Abe Y , Yang MCK , Labella R ,Yildiz E, Willems G. Clinical wear performance of eight experimental dental composites over three years determined by two measuring methods. Eur J Oral Sci 2001:109:273-281. Address for correspondence: Chakalov I. Department of Prosthetic Dentistry, Faculty of Dental Medicine - MU Sofia 52 Orthodontics Epidemiological study of the orthodontic status and permanent canine eruption in children and adolescents aged between 7 and 18 years H. Arnautska1 and V. Krumova 2 SUMMARY Introduction: Formation of the permanent dentition starts with the first permanent molar after 6 years age or with the change of incisors and ends with erupting and development of the roots of the second permanent molar. It is shown in the literature that canines are the second impacting teeth in frequency after the third molars. The data of several authors varies between 0,9% to 3,3%. The prevalence of maxillary canine retention, gives us a reason to conduct an epidemiological study. The aim of the epidemiological study was to determine the incidence of dental and jaw anomalies in different age groups from 7 to 18 years and problems with erupting of their permanent canines. The presence of different dental and jaw anomalies in our study group of 1175 children was significantly higher – 945 (80,43%) of all examinations. The improper canine eruption in both jaws was observed in 229 (24,23%) children of all cases of children and adolescents with malformations. There is significantly higher percentage of cases with abnormal I dental Angle class – 559 (47,57%) compare to other classes. Dental-jaw anomalies occur in very large numbers of children in the early formation of the permanent dentition and maintain this high rate of growth until the completion of the jaws. The maxillary canines are particularly important for the proper formation of permanent teeth because they complete their development late and have the longest path of eruption treatment for forming and maintaining an intact permanent dentition. Key words: impacted canines, epidemiological survey, occlusion anomalies 1 2 Assistant at the Department of Paediatric Dental Medicine and Orthodontics, Faculty of Dental Medicine, Varna Professor, D.M.Sc., Head of Department of Orthodontics, Faculty of Dental Medicine, Sofia 53 Introduction Development of permanent dentition starts with the eruption of first permanent molars or replacement of incisives after the age of 6 years and completes with the eruption of second permanent premolars and development of their radices. During this continuous period, many etiologic factors may influence the eruption of permanent teeth, which impose the necessity of duly prophylactic examinations. In terms of dentition development, canine teeth form early and erupt late, as the total time of their eruption is the longest, compared with these of all other teeth. In the literature, canines are indicated to be the second, regarding incidence of impaction, after the wisdom teeth. Data on frequency of canine impaction, presented by a number of authors, range from 0.9% to 3.3% (1, 2, 5, 10, 13), while in private orthodontic practice, even a higher percentage has been reported (12). Frequency of canine impaction varies among different populations and it is 5 times higher in individuals of the Caucasian race, compared with individuals of the Asian race (8). Unilateral impaction is more common (16), while bilateral impaction is significantly rarer. According to Bishara (7), bilaterally impacted canines account for 8-10% of the total number of impacted canines. Palatal impaction is more common than vestibular impaction and in a number of publications, the ratio between them is estimated to vary from 2:1 to 9:1 (10, 5, 17); the incidence of mandibular canine impaction is lower than this of the other teeth. Several authors have shown that abnormal eruption is associated with additional orthodontic deformations, such as hypodontia of the lateral incisive (3, 6, 15, 16), persisting deciduous canines (8), presented sagittal deformations (4, 15). Varying data of both incidence and pattern of canine impaction gave us grounds to conduct an epidemiological study of problems related with canine impaction and orthodontic status of children and adolescents aged between 7 and 18 years. The aim of the conducted epidemiological study was to determine the incidence of dento-jaw anomalies and problems related with permanent canine impaction in students aged between 7 and 18 years. Material and methods A total of 1,175 students from first to twelfth grade at two schools in Varna city were randomly examined. They were distributed into three age groups, based on traced dentition development: the first group included 7-9-year old children (early mixed dentition), the second group comprised 9-12-year old children (late mixed dentition) and the third group included 12-18year old children (permanent dentition). The school boards and parents were informed about the necessity of prophylactic examinations. The children were examined by using individual pairs of gloves and individual sterile instruments, where needed. The examination data were recorded in a statistical list, used for the performed examinations. The patterns of deciduous teeth replacement, occlusal relations according to Angle’s classification and deviations in permanent canine eruption for both jaws were diagnosed. The statistical analysis of results obtained was performed by using the statistical software SPSS 5.0 for Windows. The χ² test was used to compare qualitative variables and the correlation analysis was applied to examine the inter-variable relations and to determine the inter-variable relationship. Student’s criterion (t) was used for the comparative analysis of data and determination of a statistical difference between the variables studied. Results and discussion The distribution into age groups and the relevant occlusal deviations are presented in table 1. 54 Relevant occlusal deviations Age groups 7 – 9 y. 9 – 12 y. 12 – 18 y. All ages Examined children n 268 414 493 1175 % 22.81 35.23 41.96 100.00 Without Dento-jaw anomalies n % 28 10.45 73 17.63 129 26.17 230 19.57 Dento-jaw anomalies Class I n % 142 52.99 196 47.34 221 44.83 559 47.57 Dento-jaw anomalies Class II n % 96 35.82 142 34.30 135 27.38 373 31.75 Dento-jaw anomalies Class III n % 2 0.75 3 0.72 8 1.62 13 0.94 Total Dento-jaw anomalies n % 240 89.5 341 82.37 364 73.83 945 80.43 Table 1: Distribution into age groups and relevant occlusal deviations The different number of children into the individual age groups corresponded to the relevant number of students in both schools. As shown in the table, the number of children in the second and third age group was similar, which enabled us to assess canine eruption-related problems in a greater sample of children. The 7-9-year age group was smaller, because of the lower number of students at this age in both schools. The results show that out of 1,175 children examined, a very low percentage of children in the three groups presented no deformations, in both terms of tooth arrangement and occlusal relations. A total of 230 children had no dento-jaw anomalies, a result that shows that only 19.57% of the examined children presented an occlusal status corresponding to a favourable prognosis for appropriate dentition arrangement. In the 12-18-year adolescents with permanent dentition, this percentage was higher (26.17%), since many of them had already undergone orthodontic treatment or duly prophylaxis. with DJA without DJA 25,40% 36,10% 12,20% 31,70% 0% 20% 40% 7 - 9 y. 38,50% 56,10% 60% 9 - 12 y. 80% 100% 12 - 18 y. Figure 5: Distribution of children, based on presented dento-jaw anomalies, among individual age groups The number of children with dento-jaw anomalies, as shown on figure 1, increased with increasing the age, as the percentage of children with presented deformations was the highest (38.52%) in the 12-18year age group. There was no, however, a statistical correlation between the age and types of presented deformations. The data obtained show that in the three age groups, generally, a significantly low percentage of children (0.75% - 1.62%) had Class III deformations, which are the most problematic for appropriate dentition arrangement. Our results support the opinions of several authors (2, 9, 15) that in ectopic canine eruption, different malpositions of teeth are of essential significance rather than sagittal relations of the jaws. The distribution of permanent canine eruption among the individual age groups is presented in table 55 Late eruption of 313 313 Age groups Class I Total children with deformations Class II Without space 313 313 Palato position Class III Without space 313 313 Palato position With out space 313 313 Total – children with problems with canines Palatp position n n % n % % 7 – 9 y. 240 25.40 6 2.54 8 3.33 9–12 y. 341 36.08 43 12.61 18 12-18y. 364 38.52 49 13.46 30 All ages 945 100.0 98 % n 4 1.66 - 5 13 3.81 8.24 4 1.10 36 n 21 % n % - 4 1.66 1 0.3 8 1 0.28 21 2 % n % n 4 1.66 2 0.83 - 2.35 3 0.88 4 1.17 5.77 5 1.37 - - 33 n 12 6 % n % n % n % n % - - - - - - - - - 28 11.67 - - - - - - - - - - 90 26.39 1 0.28 - - - - - - - - 111 30.49 229 24.23 1 - - - n - % Table 14: Distribution of permanent canine eruption among the individual age groups For both jaws, the results show that abnormal canine eruption was observed in 229 (24.23%) out of the 945 children and adolescents with deformations. The highest percentage (48.50%) of children with problematic canine eruption was registered in the 1218-year age group (Figure 2). 100,00% 88,30% 69,50% 50,00% 0,00% 11,70% 7 - 9 y. other deformations problematic canines 12.20%39,30% other deformations 29,60% 35,10% 48,50% 35,30% 0% 20% 40% 60% 80% 100% 7 - 9 y. 9 - 12 y. 12 - 18 y. Figure 6: Distribution of occlusal deviations and canine eruption deviations among individual age groups A tendency of an increasing incidence of problematic canine eruption from 11.70% to 30.50% was observed in the 7-9-year age group and 12-18year age group, respectively, compared with the frequencies of occurrence of other deformations (χ2 = 27.98, p < 0.05) (Figure 3). 73,60% 26,40% 9 - 12 y. 30,50% 12 - 18 y. problems with canines Figure 7: Tendencies of abnormal canine eruption and other deformations with increasing the age. Our results comply with the opinions of several authors (3, 14) that there is a need of the earliest possible prophylactic measures for duly removal of several etiologic factors related with abnormal canine eruption and for monitoring the appropriate dentition arrangement (11, 12). The results of mandibular canine eruption are of particular interest, since in our country, there are almost no studies on this issue. In 56 (7.24%) of the 918-year old children with deformations, problems were observed with the eruption of mandibular permanent canines, which should had already erupted (t = 13.81, p < 0.05). In the 12-19-year age group, where the maxillary canines should be already erupted, difficulties in canine eruption or respective ectopic positions were 56 found in 76 (20.88%) of the children, which shows that in this study group, every fifth child will experience problems in achieving an intact dentition arrangement (r = 0.27, p < 0.05). Problems with maxillary canine arrangement increase with increasing the age, compared with these of mandibular canine arrangement (χ2 = 20.76, p < 0.05), the latter being most common among the children aged between 7-9 years (figure 4). 3,60% 12 - 18 y. 9 - 12 y. 56,60% 7 - 9 y. 0% 20% maxillary canines withot space 23,30% 40% 60% 18,80% 21,50% 42,80% 35,70% 1,8 31,50% 63,10% 80% 1,3 100% mandibular canines palatal position Figure 8: Distribution of canine deviations among individual age groups eruption In contrast, palatal positions of maxillary canines were not observed in the youngest age group, although the great space deficit in the dental arch, a fact that is associated with the eruption time of maxillary canines. Although slight, an increase of palatal positioning was observed in the older age groups, despite the small space deficit in the dental arch. The increasing percentage of cases with ectopic canines shows that despite jaw development at this age, the autoregulation of canine position remains impossible and, therefore, one of the most serious problems for appropriate dentition arrangement. The results of the performed epidemiological study gave us grounds to conclude the following: 1. The presented incidence of various dento-jaw anomalies in the study groups of 1,175 children was significantly high: 945 (80.43%) of all children examined (χ2 = 29.76, p < 0.05). 2. A significantly higher percentage of cases with Class I deformations according to Angle’s classification was observed, compared with these of the other classes: 559 (47.57%) of the children, compared with the other classes (t = 13.33, p < 0.05). 3. A significantly higher percentage (24.23 %) of children with problems in maxillary and mandibular canines was observed (t = 8.40, p < 0.05). 4. No children with Class III-related problems in permanent canine eruption were found in the study groups. Conclusion Dento-jaw anomalies occur in a great number of children even in the beginning of permanent dentition arrangement; this high incidence remains unchanged till completion of jaw growth. Permanent canines, having the longest path to move through and reach their normal place in the dental arch and having the longest eruption time, are of crucial importance for the appropriate dentition arrangement. The results obtained show that duly prophylactic measures are needed for normal canine eruption and orthodontic treatment is required for the appropriate arrangement and maintenance of an intact permanent dentition. Reference 1. Апостолова В. Честота, клинична характеристика и причини за възникване на аномални положения на третите зъби. Дисертация, С., 1974, 313 c. 2. Ганева Зл. Лечение на някои ЗЧД чрез изваждане на постоянни зъби. Дисертация, С., 1971, 224 c. 3. Baccetti, T. A controlled study of associated dental anomalies. Angle Orthod., 1998; 68: 267-274. 4. Basdra, E. K., Kiokpasoglou M., Stellzig A. The Class II division 2 craniofacial type is associated with numerous congenital tooth anomalies. Eur. J. Orthodontics, 2000; 22:529–535. 5. Bass, T. B. Observations on the misplaced upper canine tooth. Dent. Practit., 1967; 18:25-33. 6. Becker, A. Palatal canine displacement: guidance theory or an anomaly of genetic origin. Angle Orthod., 1995; 65:13-7. 7. Bishara, S. E. Impacted maxillary canines: a review. Am. J. Orthod. Dentofacial Orthopedics, 1992; 101: 159-171. 8. Bishara, S. E. Clinical management of impacted maxillary canines. Semin. Orthod., 1998; 4:87-98. 9. Dachi, S. F., Howell F. V. A survey of 3874 routine full mouth radiographs. Oral Surgery, Oral Medicine, Oral Pathology, 1961, 14:1165-1169. 57 10. Ericson S., Kurol J. Radiographic examination of ectopically erupting maxillary canines. Am. J. Orthod. Dentofacial Orthopedics, 1987; 91: 483-492. 11. Ericson S., Kurol J. Early treatment of palatally erupting maxillary canines by extraction of the primary canines. Eur. J. Orthodontics, 1988; 10: 283–295. 12. Ferguson J. W. Management of the unerupted maxillary canine. Br. Dent. J., 1990;169:11-7. 13. Grover P. S., Lorton L. The incidence of unerupted permanent teeth and related clinical cases. Oral Surg. Oral Med. Oral Pathol., 1985; 59:420-5. 14. Jacoby, H. The etiology of maxillary canine impactions. Am. J. Orthodontics, 1983, 84: 125-132. 15. Langberg, B. J., Peck S. Adequacy of maxillary dental arch width in patients with palatally displaced canines. Am. J. Orthod. Dentofacial Orthopedics, 2000b, 118: 220–223. 16. Oliver, R. G., Mannion J. E., Robinson J. M. Morphology of the maxillary lateral incisor in cases of unilateral impaction of the maxillary canine. Br. J. Orthod., 1989; 16:9-16. 17. Thilander, B., Jakobsson S. O. Local factors in the impaction of maxillary canine. Acta Odontol. Scand., 1968, 26: 145–168. Address for correspondence: Prof. Dr. V. Krumova Department of Orthodontics, Faculty of Dental Medicine,MU – Sofia 1 St.G.Sofiiiski str., Sofia, 1431 58 Public Dental Health Demographic processes and structure of the dental practices as prerequisites for market development of the dental services in Bulgaria K. Tzokov1, L. Katrova¹ SUMMARY The aim and social characteristics of this study is to demonstrate the influence of demographic of the population on the development of dental practices and the market of the dental services. Material and Methods: Secondary data analysis. Results: During the last two decades the population in Bulgaria, especially bellow 65, has been steadily decreasing while the number of dentists markedly increased. The change in the structure of dental practices is presented by an increase of the number of general dentistry group practices, a decrease of the number of individual and group practices for specialized dental care and a decrease of the number of dental centers, is observed. For the period of20 years only 1/3 of the specialist positions were fulfilled. Utilization of the Dental Health Service is about twice lower than the utilization in EU. Conclusion: 1. Sustained trends of decrease of the number of the population and the prevalence in aging population groups, correlate negatively with the increasing number of dentists. 2. Prevalence of aging groups implies increase of treatment needs but not automatic increase of the demand for dental services. Key words: demography, dental care facilities, utilization of the dental health service, dental care market . 1 ·MU -Faculty of Dental Medicine, Sofia, Department of Public Health 59 Introduction Demographic data on Bulgaria for the last 20 years show a steady trend towards reducing the number of the population, aging group prevalence and uneven distribution of the population through the country [12]. Contrary to the reduction of the population's number, the number of dentists for the same period increased [1,14]. In the same time, the dental delivery system in Bulgaria for the same period, evolved from 100% public in almost 100% private practice [9]. Dentists now work in a real market environment with elements of regulation 1. Along with the introduction of new market relationship the dental practices structure is changing as well [6]. A number of new, and yet unexplored socio-economic conditions aroused. As a result the access to dental care was affected and the utilization of health services consequently diminished [10]. The aim of this study is to demonstrate the correlation between demographic and social changes in the population and the development of dental practices by the country as a whole and by regions and how these processes influence the formation of dental care market for the period 2000-2010. In connection with the set objective the following tasks were formulated: 1. Brief presentation of demographic data on the population 2. Brief presentation of data on dentists and dental practices 3. Brief overview of changes in the structure of dental practices. 4. Utilization of the dental service Results and discussion 1. Presentation of demographic data on the population by regions According to the official sources of demographic data, (NHIC and NSI) the number of the population of Bulgaria decreased significantly for the study period of 20 years (between 2000 and 2010) [14]. The study of the demographic situation by regions confirmed the existence of the leading common problem for the country as a whole -reduction of the number of Bulgarian population. The distribution of the population over the regions is uneven. Against the general trend of reduction of the population, the regions of Bourgas and Sofia region retain a relatively constant number of population. Increase of the number of the population is observed in the cities of Sofia and Varna. (Fig. 1) [12] Material and methods The study is based on the analysis of secondary data. Data were issued from the official publications of the NCHI 2, the NSI 3, the BgDA 4 and the review of literature following keywords 5. Figure 9: Change of the number of the population in Bulgaria and some region 1 A minimal package of dental services is covered by a public fund (National Health Insurance Fund) and a fixed rate of prices is voted every year upon the Frame Contract between the profession and the Fund. 2 National Center for Health Information 3 National Statistical Institute 4 Bulgarian Dental Association 5 Demography, Medical institutions for dental care, utilization of dental health service, dental market 60 The age structure of the population, presented in Table 1, shows a slow but stable trend towards decrease of the number of young people and a considerable increase in population over 65. The number of the working population gradually decreased from 2000 to 2005 years, then slowly increased and remained stabilized in recent years. The percentage of working population is significantly higher in cities, while the villages are more or less depopulated. The unemployment rate for Bulgaria is Year Age group 0-17 1970 1995 2000 2005 2007 2008 2009 27.5 22.0 19.5 17.5 16.9 16.7 16.7 18-64 65+ Total population 62.8 9.7 62.8 15.2 64.1 16.4 59.6 22.9 65.8 17.3 65.9 17.4 65.8 17.5 1970 1995 2000 2005 2007 2008 2009 28.1 22.9 20.0 17.7 17.1 16.9 16.8 65.3 65.6 67.7 68.7 65.0 69.1 68.9 relevant to the population purchase power, in particular the search for dental services. The underemployment and unemployment rate is touching young and low educated people. The share of longterm unemployed (2 or more years) is going up [4,13]. 2. Information on dentists and dental practices The concentration of population in more densely populated areas is expected to generate bigger treatment needs. These areas are attractive to dentists too. The regions of Sofia-city, Plovdiv, Varna have a consistent number of dentists and unfavorable dentists/patients 'ratio [14]. According to NHIC data after sustainable increase of the number of dental practitioners for the period (19802000) (from 4839 to 6778) the number of dentists now keeps its level (Fig.2). 6.6 11.5 12.3 13.6 13.9 14.0 14.3 1970 26.8 60.0 13.2 1995 20.1 57.0 22.9 2000 18.6 56.3 25.1 2005 17.0 57.4 25.6 2007 16.5 57.9 25.6 2008 16.3 58.1 25.6 2009 16.1 58.2 25.7 Table 1: Dynamic of the process of urbanization by age groups distribution Figure 2: Change of the number of dental practitioners for the period 2000-2010 61 3. Overview of changes in the dental practice A review of official data on dental practices shows that for the period from 2000 to 2007 the number of the individual general dental practices increased, followed, by a decrease between 2007 and 2009. Constantly growing is the number of the general dentistry group practices. The number of Table 2: Outpatients clinics for dental care, dental practices individual and group practices for specialized dental care was going down. The number of dental centers, registered a decline, while relatively constant remained the number of medico dental centers (Table 2). For 20 years period only 371 dentists have acquired specialty, which represents less than one third of the group of retiring specialists `(7). 62 4. Utilization of the Dental Health Service: According to BgDA only 45% of patients had visited a dentist during the previous year, while in EU countries the percentage varies from 88% to 71% [3]. Conclusion 1. The long term trend for decrease of the total number of the population correlate negatively with the increasing number of dentists in Bulgaria. 2. The prevalence of aging population implies some potential increase of the dental needs, but the low purchase power is stopping the demand for dental services. 3. Research should be focused on the dental service's utilization and the dental practices' preparedness to respond the real demand for dental services. Reference 1. Катрова, Л.Г.П. Стоматологичната професия–състояние и перспективи. ЛТД Пъблишинг София, 1998, 290 с. 2. Катрова, Л. Кр. Цоков, Цв. Катрова. Промяната на социално–професионалния статус на стоматолозите в България в хода на здравната реформа. ИМАБ 2002 том 8 №1, стр. 18-21. 3. НЦЗИ, Кратък Статистически Справочник – здравеопазване, електронно издание – 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 г. 4. Гладков, Ол. Eвробарометър. 02. 2010, тема-Орална здраве. http://ec.europa.eu*public_opinion/archives/ebs/ ebs_330_eu.pdf 5. http//www.nsi.bg/census2011/index.php – НСИ, преброяване 2011г. 6. Регистър на БЗС-списък на членовете по районни колегии 2000 – 2010г. 7. Katrova L. P. Bojinov, I. Mihailova. Oral Health Care reforms in Bulgaria during the period of transition. Oral health and Dental Management in the Black Sea Countries, Vol. VI, 2007, No 4, pp 38, ISSN: 1396-5883. 8. Катрова Л., Хр. Кисов. Ученето през целия живот - задължение или привилегия за лекаря по дентална медицина, продължаващото следдипломно образование – задължение или привилегия за факултетите по дентална медицина. Проблеми на денталната медицина, XXXVI, 2010, №2, с.28-36, ISSN: 0323-9403. 9. Katrova L. Leading trends in dental profession demography in Bulgaria for the period 1996-2008 (OP112). 14 Congress of BASS, 9th Scientific Congress of the BgDA. 6-9 May 2009 Varna (доклад). 10. Шипковенска Е., Методология на научноизследователската работа, Здравна политика и мениджмънт, 2011, том 11, №1, ISSN 1313-4981. 11. Катрова Л., Папанчев Г. и др. Удовлетворяване на потребностите от лечение на кариеса и неговите усложнения в условията на здравно осигуряване, Проблеми на стоматологията, том ХХХ/2004, с. 63-68, ISSN 0323-9403. 12. Катрова, Л. Професионално-демографски аспекти на структурната реформа в стоматологията Стоматол. преглед, т. 29, 1998, №2, с. 11-28. 13. Катрова, Л., М. Грашкина. Използваемост на стоматологичната здравна служба в преходния период. (1999-2000), т. 27, 2000 с. 115-125, ISSN 0323-9403. 14. Катрова Л. Генерационна мобилност в зъболекарската професия, приемственост и перспективи Soc. Med. Sofia, 17, 2009, No 3, с. 29-32, ISSN: 1310-1757. 15. Ранчов Г. Биостатистика и биоматематика: концепции, методи, приложения. София, 2008 ISBN: 978-954-910849-1. 16. Регистри на БЗС за 2008, 2009, 2010, 2011. 17.http://www.bzs.bg/site/index.php?option=co m_content&task=view&id=964&Itemid=664. Address for correspondence: Dr. Kr. Tsokov Department of Public Health Faculty of Dental Medicine, MU-Sofia 1, St. G. Sofiiski Blvd., 1431, Sofia Phone: +359 889 25 17 88 63 Review Children with special health care needs and prevention of oral diseases in this population L. Doichinova1 SUMMARY Oral health of children with disabilities requires more attention than usual and is a real challenge to the dental professional and his team. There are a number of reasons, which necessitate children with disabilities to be subject to dental medicine special care. Their oral health differs from that of their normal coevals, for example higher incidence of periodontal diseases in children with Down syndrome, teeth abrasion in children with cerebral palsy. The prevention of dental diseases in children with special health care needs should have higher priority than in healthy children. Treatment planning and dental care delivery may require modifications depending on the patient’s abilities, possible future cooperation and home care. The preventive measures should be encouraged and personal instruction respectively performed, as well as screening and preventive individual programs should be developed in order to minimize the oral problems with this population. Dental professionals, dealing with such patients, must have a lot of imagination, inventiveness and flexibility. Individual adaptation and modification of the traditional procedures is necessary, as well as patience, calmness and politeness while working with special needs patients. Key words : Special needs children, oral health, education, communication, behavioral problem 1 Assistant professor, MU-Sofia, Faculty of Dental Medicine, Department of Pediatric Dental Medicine 64 Introduction Childhood is a period, marked by dynamic processes of growth and development of the child’s organism and complex processes of setting up the functions of oral structures. The congenital and early acquired defects in the child’s organism affect the individual development. Anomalies change the entire life activity of the child including adequate oral structures construction, which worsens oral health. Preventive measures in these cases, such as rational nutrition, fluoride preventive measures and oral hygiene are of vital importance for its improvement. Each community has a group of children with disabilities, which put them in an unfavorable situation compared to the others. Some of them have deviations in their oral health, such as higher incidence of periodontal diseases in children with Down syndrome, tooth abrasion in children with cerebral palsy, higher rates of untreated caries, more missing teeth. The higher risk of oral disease development in children with developmental problems turns prevention into even more vital priority compared to other children. Their treatment is difficult as it requires special conditions and may need a lot of time, spent in specialized clinics and multi-purpose hospitals. Quite often it is held only in “cases of emergency” (1). Investigations show that about 500 million people worldwide have some disability. NSSI (National Social Security Institute) statistics state that in Bulgaria there are 850,000 disabled individuals, 147 000 of them being children with specific abilities, those permanently handicapped reaching 30,000 (per expert evaluation). The inadequate development of alternative services and care for children with special needs and support of their families determines the large number of those, raised in social homes within the system of various ministries in isolation and completely inappropriate conditions. Per data of a study, held by the State Children Protection Agency (SCPA), the number of institutionalized children with mental retardation, psychic, physical and sensory disabilities is 18,695, 11,776 of them in institutions of MOES (Ministry of Education and Science), 5,440 in such institutions of Ministry of Labor and Social Care (MLSC) and 1,479 in such, managed by the Ministry of Health (MOH). The high degree of their institutionalization results in strong reduction of the possibilities to provide good health care, including dental care and prevention. The maturity of society is illustrated by its attitude to the poor and the handicapped. Each country is obliged to take care of the health of every man, its top priority being those who most badly need such care. Our society has its pending duty to children and people with disabilities. Social and medical aspects of dental care in children with special needs Per the definition, adopted by the Board on Clinical Activities to the American Academy of Pediatric Dentistry (AAPD) in 2004 “certain people have special health care needs if they have problems in their physical, mental, sensory, behavioral, cognitive or emotional development, which limits their functions and necessitate medical management, health care intervention and/or use of special services or programs. This condition may be manifested in the process of individual development or be acquired and results in limitations of carrying out daily self-care activities or significant restrictions in major life activities. Health care of patients with special needs exceeds the routine practice and requires specialized knowledge, better awareness and attention, as well as adjusting to these requirements.” (26). According to AAPD the main objective of pediatric dental medicine is to attain maximum health level for all children, including those with special health care needs (27). The special dental care needs of this group of children are determined by the existing barriers to oral care delivery and by the increased risk of oral disease development. The barriers, restricting normal oral care for children with physical, psychic, sensory and emotional handicaps are define by objective and subjective prerequisites (18). One of the objective factors worth mentioning is lack or deficit of financial resources in the majority of the families of these children, as they predominantly rely on state funding for payment of their medical or dental service (77). Other factors, limiting the access of this population to dental care are the demand of more time, dedicated by the family to get the service needed, the limited transport resources to the dental office or center and 65 all the difficulties, caused by it, requiring specially adjusted vehicles and appliances, facilitating the move (77). Generally these children don’t have adequate access to private health insurance in getting health services (18). A major subjective factor, substantially limiting oral care application in this unique population of children is the inability to understand, cooperate and take responsibility for the preventive procedures and treatment, protecting their oral health (87, 77). Other factors, which may hinder the access of these patients to dental care are language or cultural barriers. (27). Children with special needs have lower protective factors and inappropriate behavior as to oral diseases (6). Lack of information and knowledge on oral diseases and their consequences on behalf of the parents, the general practitioner or the dental doctor might also be one reason of limiting preventive dental care (26). Other series of circumstances, such as longer time for feeding, special diets, using food as reward, oralmotor or general motor dysfunctions, resulting in poor oral hygiene, insufficient addition of systemic fluorides, over-commitment of parents/guardian with child's disabilities, as well as parental or institutional ignorance and/or negligence of oral health put disabled children in the high risk group for the development of oral diseases (82, 88). Patients with special needs may demonstrate higher degree of anxiety during dental manipulations than those without disabilities, which can adversely influence the frequency of dentist appointments and consequently their oral health (50, 78, 49). In their study Oredugba et al report that a very small number of dentists have adequate knowledge on treatment of children with special needs, irrespective of their gender, age or dental practice location (70). Historically many of these patients get dental care in special homes and state institutions (87). The trend nowadays is the children with special needs to get dental care in standard dental centers or by doctors in private dental practices (35). The existing Act on People with Disabilities in the US sets the dental office as place of public significance. Avoidance to treat patients with special needs may be treated as discrimination and violation of a federal and/or state law (27, 35). The regulations require by the practicing dentists to ensure physical access to their dental practices, such as ramps for wheelchairs, parking places for handicapped, special rails, etc. (35). The Faculty of Dental Medicine in the University of Seattle, Washington has a special program DECOD - Dental Education in Care of Persons with Disabilities, which provides dental health care to over 2000 disabled patients annually. Approximately 60% of them have severe disabilities, such as mental retardation, cerebral palsy or autism. The University has a program awarding scientific degrees to students, who monitor the treatment planning of populations with special needs. There are short-term and longterm specializations with scholarships and additional self-training modules with video tapes for those students, interested to learn how to provide dental care to this unique group of the population. The students work regularly with their lecturers from the faculty in social homes for at least one semester (43). The American Association of Faculties in Dental Medicine develops curricula with specific guidelines on dental care for people with disabilities (43). The US Commission on Dental Accreditation (CODA) includes in the accreditation standards training on delivery of oral health care to people with special health care needs (62). Supporting methods and means in providing oral care to disabled children During the treatment and preventive procedures of patients with special needs it is of substantial significance to have an assessment of the mental status or the degree of intellectual function in order to be able to establish good communication (50). A patient, who does not communicate verbally, can maintain communication in a number of untraditional ways. In case of unsuccessful communication one should look for the most effective way of establishing a contact with such problematic patients (35). The effective communication is of prime importance for patients/parents with hearing problems, which can be attained by a variety of methods and techniques, including interpreters, written materials and lips reading (65). Getting information on the way a patient with intellectual or physical difficulty communicates 66 is an important goal in the overall work of the dental doctor (50). Many patients are likely to have not only hearing difficulties, but also difficulties related to speech and/or language. The receptive language (what is being heard/accepted) and the expressive language (what is being said) are frequently speech/language areas, which raise problems (67, 50). The ability to follow instructions, learn new things and articulate desires and needs may be difficult for some patients with intellectual and physical difficulties (50). Many of them rely on verbal or non verbal prompting, others do not understand language, which differs from the verbal one and that is why it is important for the dental specialist to know the way, in which the patient establish communication (67, 68, 50). Some of the patients need supporting aids such as Alpha Smart (small portable computer) or system of picture communication P.E.C.S. (Picture Exchange Communication System) (50). The latter is an alternative technique for those, having low or no verbal skills. The booklet consists of pictures on expressing desires, observations and feeling. It grows with the growth of the patient, adding more words and pictures and helps a lot to those, who do not speak (50). Such patients have a wide range of behavioral and emotional problems, the impulsiveness and the low annoyance threshold being frequently present (67, 50, 68). They often loose speech or physical control and may need physical/verbal prompts to trigger the necessary reaction or calm them down (50, 68). As to speech they may use inappropriate language or speak when the time is not appropriate. As to physical signs they may pinch themselves or others, slam their head in the wall, bite themselves or bite others or cause vomiting (50). Behavior management of patients with special needs may be another challenge to the dentist and his/her team. Stubborn, repetitive behaviors are often manifested in individuals with mental retardation and such with purely physical disabilities and normal intellectual capacity. These behaviors may hinder safe treatment in the dental office (27). The protective stabilization can be of help to patients, where the traditional behavior management techniques are insufficient (23). In cases when this is not enough for delivering qualitative dental care, the behavior management choice left is relevant sedation or general anesthesia (13, 12, 81). For proper diagnose and effective treatment planning it is necessary to have an accurate, comprehensive and correct medical history (27). The medical history information should include also what may annoy or calm down the patients, since it is important for the delivery of dental care (50, 67, 68, 22). Getting acquainted with the medical history of the patient with special needs is of great importance also for reducing the risk of worsening his medical condition by dental care delivery(27). In the US it is recommended for an appointment of patient with special needs the dentist to be acquainted with and strictly follow the requirements of Health Insurance and Accountability Act and the Act on People with Disabilities, related to dental practices (35, 36). The first one guarantees patient privacy protection, while the second prevents any disabilityrelated discrimination. When working with these patients it is also necessary to have a well-documented informed consent, given by the patient himself or someone, eligible to do so and it should be recorded in the patients’ record, proven by an enclosed informed consent form, signed in the presence of the dental professional (23, 20). Prevention of Oral Diseases in Disabled Children Preventive dental care to disabled children is limited as they either don’t look for it or the dental professional don’t treat them except for cases, when alleviating the pain symptom is badly needed (67, 22, 68). Treatment is carried out only in “case of emergency” and the service level is not at all good (1). While for the normally developing children dental interventions are accepted with not so pleasant feelings, for those with special health care needs irrespective of their nature - preventive measures or dental treatment - they are characterized by complete lack of collaboration (22, 1). The issue about organizing the oral disease prevention with this group of children should be considered very seriously due to lack of capability to take own decisions referring to their own health (1). Parallel to that it is established that oral diseases are second in significance after the severe general condition of the children with special needs (22). 67 They are exposed to higher risk of developing oral diseases (86, 32), while oral health is an integral part of general health and wellbeing of each individual (27). Oral diseases may further jeopardize the health of the patient with special needs and therefore prevention is needed (86). For this group of patients the chronic character of tooth caries and periodontal disease may cause complication of the underlying disability (70, 42, 48). The tooth caries incidence is higher compared to their healthy peers, almost 2/3 of children with mental retardation and physical handicaps being institutionalized and having inadequate access to dental care (88, 39, 90). For many children with special needs the risk of caries development is larger due to poor oral hygiene and worsened general health (8). Large part of them are unable to maintain independent oral care (67, 68, 8, 22), while others cannot brush their teeth properly due to mental and/or physical problems (22, 67, 8, 68). In such cases the parents or caretakers should be trained and prepared to take responsibility to conduct oral hygiene care at home, which is important in order to ensure proper and regular control of daily oral care (22, 67). It is necessary to show oral hygiene technique and procedures, including proper positioning of the disabled person (27, 20). In developing home oral hygiene programs it is necessary to choose the most suitable position of the patient and the caretaker provided independent brushing is impossible (22, 8, 67). According to Nowak (67) and other authors, because of the serious risks of its early onset, parents should get all the necessary information on prevention of incipient tooth caries, learn what is their role in the process of ensuring the dental health of their own child and strictly follow the recommendations of both the pediatrician and the dental professional (8, 22, 68). Besides the key etiological factors, namely plaque bio-film, diet and time, there are also additional factors contributing to the development of tooth caries in children with special health care needs such as: hypoplasia of the enamel, its morphological changes, compressed front, carbohydrate diet, consumption of sweets, snacks, soft food, lack of collaboration, mental deficit, physical limitations, lack of funds, institutionalization and lack of care (67). More and more caries management strategies emphasize on the concept of caries development risk assessment (73, 88, 64, 72). For children with special needs it should be done, because they face higher risk of developing oral diseases as a result of their disability (68). The caries risk assessment should be performed periodically in order to assess all the changes in the risk status of the child with special needs (27, 32, 73). It serves as basis for caries management strategy (28, 37, 31, 34) and allows proper clinical decisions to be taken for these children (91). The caries risk assessment tool (CAT) is based on a set of physical factors, such of environment and general health factors and represents a dynamic tool, which can be periodically assessed and revised when data require such revisions (33, 45, 46, 88, 91). In Bulgaria such caries development risk assessment tool was also developed by Rashkova et al. which is easy to use and examines the oral environment risk factors and their connection to certain pathology noticed in the oral cavity (72). The contemporary dynamic carious process understanding outlines the possibility of stationing it while still in its active stage at any moment prior to the stage of cavitation (4, 7). The caries activity assessment is considered to be most important in assessing the carious process (4). Most of the studies do not report lesions without cavitation (91, 58, 47) though such lesions have their proven value for the projected estimation (490). With the existing possibility of detecting tooth caries in its incipient stages (lesions having the shape of a white spot) the dental professional can help preventing tooth cavitation (53, 85, 4). It is proven that by the application of amorphous calcium phosphate (АСР) and casein-phosphopeptides (СРР) that re-mineralization of the incipient caries in the subsurface enamel layer is possible (7). It is established that even if there is progression of the process with clinically detectable lesion, its development can be inhibited and the lesion remain stable for months and years ahead(9). Such lesion can be re-mineralized by eliminating the cariogenic factors: plaque bio-film, change of diet and improving the activity of the protective factors (fluoride, increased saliva flow, re-mineralizing agents) (9, 7, 10). 68 There are available scientific data that chewing gums with Хylitol and Sorbitol help reducing the tooth caries risk and are very useful to disabled persons (74, 76, 59). Studies reveal that those preferring chewing gum with Xylitol register highest reduction of caries development risk (61, 60, 71, 54, 55, 57). Xilitol is sugar substitute, which has excellent effect for tooth caries prevention. (61, 60, 71, 59, 21, 52, 86, 75, 74, 76, 82, 56, 54, 55, 57, 84, 80, 19, 79). There are reports on long-term effect of the use of chewing gum and sweets rich in Xylitol, rendering also favorable effect on the newly erupted teeth. It is established that within one year after regular use of rich in Xilitol chewing gums caries development risk drops by 93%, while the teeth having erupted within two years after the subjects stop using this product show 88% reduction of this risk (52). The necessity of recommendations on the efficient dose and frequency of using chewing gum or sweets with Хylitol for patients with special needs is emphasized (21, 86, 61). The combination of fluorides and Хylitol suppress the growth of Streptococcus mutans (57, 84, 79). The combination of fluoride toothpaste and use of Хylitol in chewing gums, sweets or as toothpaste and mouth rinse ingredient has even better caries protective effect (76, 82). In cases of xerostomy, which is frequent side effect of drugs, prescribed to disabled persons, Xilitol has excellent effect, as it increases the saliva flow (19) and strongly reduces the acidogenic potential of the plaque bio film (57, 84, 19, 79). It is established that it also strengthens the tooth enamel by stimulating the re-mineralization effect of saliva, facilitates the absorption of calcium by the tooth surface and reduces the ability of microorganisms to stick to it (59, 57, 84, 79, 19). It is reported that the polyoles, natural sugar substitutes – sorbitol, manitol and xilitol – are difficult to be dissolved by the oral cavity microorganisms (55, 57). Streptococcus mutans can successfully dissolve only sorbitol and manitol, but not th xilitol, which is identically sweet as sugar and satisfy the need of getting sweet food, at the same time significantly reducing the tooth caries risk (61, 60, 71, 59, 21, 52, 86, 75). Dental team prime responsibility is to provide information and training of the patient and caretaker, which should end up by drafting an individual prevention plan, tailored to his/her individual demands, and if needed also by developing a therapeutic plan relevant to the specific oral cavity condition, which to ensure the patient’s oral health protection and promotion (22). It is underlined that the oral health of such persons is affected by various social-demographic factors, living conditions and the severity of the specific disability (69). What is being recommended is the individual prevention program and new appointments schedule with the dental professional for prevention to happen only after caries risk assessment as well as assessment of the patient’s oral health needs. The treatment and prevention methods and techniques to be used should be explained to the patient and the parent (27, 20). Based on the answers provided by parents to structured questionnaire on the oral health of their children, the majority of them (94%) supports the recommendations and advice for oral disease prevention and thinks that there should be explanation of the risks, which oral disease can have on general health (69). The necessity to give basic consultations on the appropriate diet, oral hygiene maintenance and fluoride supplements, free of charge, is also underlined (38). One of the most preferred sources of these advice and consultations is the family dentist (51). Parental support of regular dental check up examinations is extremely high, the prevailing opinion indicating that the children with special needs should have such regular check up exams more frequently (38). In the process of conducting such plaque bio film management program it is recommended to include also appropriate consultation on the child‘s diet and to explain the existing relation between the refined carbohydrates and oral health both to the parents and the tutors, asking for their cooperation (22). The food regimen of such patients should be discussed and instructions for changing it should be provided aiming at a long-term preventive effect on oral diseases (35). The dental professional should encourage noncariogenic diet and inform the patient/parent about the high cariogenic potential of oral pediatric medicines, rich in sugars and diet supplements, rich in carbohydrates (87, 20). It is recommendable to explain to the parents that rewarding the child with something “sweet” creates high caries development 69 risk, due to maintaining low pH of the saliva for a longer period between meals. Some children have poorer self-cleaning potential, due to weak muscle activity and coordination, as well as eventual saliva quality changes (68). The incentives for the children with special needs should include presents, praises and other privileges (6). The carbohydrate intake between meals should be eliminated and the consumption of sucrose and other highly cariogenic food should be limited, which is obligatory requirement in developing the diet recommendations to such children (22, 68, 67). It is absolutely recommended to pay attention to the adverse effects (xerostomy and gingival hyperplasia), of various drugs, used for the treatment of these children (27). There are various ways of managing these adverse effects: stimulating the residual saliva secretion with Pilocarpin, water intake in small sips, sucking ice cubes or lemon sugar-free sweets, artificial saliva such as Glandosane, Orhana, Luborant, Biotene (mouth rinse, spray, chewing gum, toothpaste) (68). The application of fluorides (fluoride toothpastes and gels, fluoride varnishes and solutions, fluoride mouth rinses, fluoride polishing pastes) is still the most effective and widely used tooth caries preventive method and an obligatory measure for children with disabilities, as they face higher tooth caries development risk (5, 67, 68, 24, 20, 22). The periodontal diseases come second after tooth caries and the risk assessment of their development is vital for the prevention, diagnostics and treatment of disabled children (4). The risk factors for their development are present in children with Down syndrome, intellectual deficit and all cases of disturbed balance between local and systemic factors (67, 4). Naka et al. studied the distribution of 10 selected periodonto-pathologic bacteria types in plaque bio-film samples, taken from disabled children (mental retardation, cerebral palsy and autism) the most frequently detected types being Capnocytophaga sputigena (28,3%), followed by Agregatibacter actinomycetemcomitans (20,9%) and Campylobacter rectus (18,2%). Eikenella corrodens, Capnocytophaga achracea, Prevotella nigrescens were less presented, while Treponema denticola, Tannerella forsythia and Prevotella intermedia were rarely detected, but for individuals having such bacteria types the likelihood of developing periodontal disease was high. Porphyromonas gingivalis was not found in any of the study participants. Usually this type is most frequently found in subjects with Down syndrome. The individuals with Campylobacter rectus, have higher depth values of the periodontal pockets, as well as higher gingival index and total number of bacteria types (63). Due to the neglected oral hygiene in disabled children it is recommendable to use sealants in order to reduce the risk of tooth caries development on their occlusal tooth surfaces (68, 67, 22). Conclusion Criterion on the social-economic development level of a given community is its attitude to the people with special needs, who are unprivileged compared to the rest of the population. The sporadic scientific papers in Bulgaria (16, 17, 15, 11, 2, 3, 14, 13, 12, 81, 10) have modest contribution to this topical issue. Up till now we do not avail of complete information on the dental status and oral diseases, present in these children and nothing has been done in the direction of preventing oral diseases within this population. They have much larger necessity of undertaking oral disease preventive measures, due to the high risk of their onset compared to that in their healthy peers, because they have limited own capacity to maintain oral care. The preventive and treatment dental manipulations is imperative due to the fact that large part of the parents and caretakers of these children neglect their importance because of lack of understanding, insufficient or lacking financial resources, serious need of more child-dedicated time on behalf of the family, lost parental employment possibilities, which leave aside the preventive dental care. Prevention is the most affordable way of ensuring good oral health, especially in patients with disabilities, since they need multiple care procedures due to their systemic condition. The need of oral disease preventive care for children with problems has higher priority than in their normal peers, because the oral disease, its pathological implications and treatment within this population group is complicated and expensive even more so in those cases when operation under general anesthesia is needed. 70 Criterion on the social-economic development level of a given community is its attitude to the people with special needs, who are unprivileged compared to the rest of the population. The sporadic scientific papers in Bulgaria (16, 17, 15, 11, 2, 3, 14, 13, 12, 81, 10) have modest contribution to this topical issue. Up till now we do not avail of complete information on the dental status and oral diseases, present in these children and nothing has been done in the direction of preventing oral diseases within this population. They have much larger necessity of undertaking oral disease preventive measures, due to the high risk of their onset compared to that in their healthy peers, because they have limited own capacity to maintain oral care. The preventive and treatment dental manipulations is imperative due to the fact that large part of the parents and caretakers of these children neglect their importance because of lack of understanding, insufficient or lacking financial resources, serious need of more child-dedicated time on behalf of the family, lost parental employment possibilities, which leave aside the preventive dental care. Prevention is the most affordable way of ensuring good oral health, especially in patients with disabilities, since they need multiple care procedures due to their systemic condition. 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Zero D., Fontana M., Lennon A.M. Clinical applications and outcomes of using indicators of risk in caries management. J Dent Educ 2001; 65(7): 1126-32. Adress for correspondence: Liliya Doichinova Department of Pediatric Dental Medicine Faculty of Dental Medicine, MU – Sofia, St.G.Sofiiski №1, 1431 Sofia, e-mail: ldoitchinova@abv.bg 74 Review Treatment of oral lesions in HIV and AIDS A. Krasteva1, Vl. Panov 2 SUMMARY It is of a great importance that dental professionals interestеd in oral medicine can diagnose oral manifestations of HIV and thus could suggest appropriate treatment to control the lesions. In the coming future HIV- infection would be diagnosed by a rapid test in the mouth. Dental practitioners should continue being in collaboration with the other specialists in order the optimal oral therapy. Key words: HIV, oral lesions,dentists 1 Department of Pharmacology and Toxicology, Faculty of Pharmacy, Medical University, Sofia, Bulgaria Department of Conservative and Paediatric Dentistry, Faculty of Dental Medicine, Medical University “Prof. Dr. P. Stoyanov”, Varna, Bulgaria 2 75 Introduction Since HIV discovery in 1981 many people have been infected worldwide. The virus affects all socioeconomic, racial, ethnic and sexual communities and continues to cause morbidity and mortality. By the end of 2010 in Bulgaria 1252 persons with HIV are already registrated, but in reality they are at least 3 times more (15). Over 65% of newly registered HIVpositive were found in free consultation dental practices in Sofia and Plovdiv, half of them were aged between 15 and 29 years, in between 32% were druginjections users and 20% are homosexual (15). 30 years after the epidemic onset the oral changes profile in HIV patients differs significantly from that in the beginning. Populations at risk change over time. Increasingly women and minorities become infected (15). Associated oral lesions are of particular importance representing markers for disease progression and for the degree of immunosuppression. It is a fact that oral changes also influence quality of life of the patients (7). Advances in medicine and technology have been contributing to early HIV diagnosis − by express tests of studied materials (saliva etc.) and to the introduction of new drug combinations for HIVpositive patients. At the same time it should be noted that new generation drugs can cause other changes in oral cavity (ulcers, taste changes, xerostomia) (7). The aim of the present review is to present the current trends in oral lesions treatment in HIV patients and to discuss the place of the dental practitioner in oral signs diagnosis and therapy. HIV-ASSOCIATED ORAL MANIFESTATIONS Candidiasis Very often oral candidiasis is the first sign of HIV infection, reaching 90% of infected. In these patients, there are four forms of candidiasis: 1) pseudomembranous candidiasis, 2) erythematous candidiasis, 3) angular cheilitis, 4) hyperplastic candidiasis. Oral candidiasis is one of the earliest manifestations of infection among drug-addicted and is a major predictor of risk of AIDS and death. It is considered that oral candidiasis develops either due to the correlation between HIV and Candida either from dysfunction of local immunity, overlying cellmediated immunity deficit or decreased level of CD4+ cells. In the recent years, many studies were reported, which is coincided with the increased importance and awareness of this opportunistic infection in HIVinfected drug-addicted (4). In 59% of patients in North and South America, China and India (19) oral candidiasis is the most common identified lesion in the oral cavity (5, 6). Data for Cuba show that only 11% of patients suffer from oral candidiasis (3). It is reported that candidiasis is the most common lesion in both groups of heterosexuals (44%) and injection drug users (28%) (13). Hairy leucoplakia Hairy leucoplakia as an early pathognomonic sign very often occurs as a white patches on the tongue sides, often with underlying candida infection. The infectious agent responsible for these lesions is Epstein-Barr virus, located in epithelial cells. The incidence of hairy leukoplakia in Brazil is higher than candidiasis – about 25% of patients are affected (5) as it is in other countries of the America (6). Heterosexual patients suffer 3 times more of hairy leukoplakia (33%) compared with injection drug users (10%) (13). In patients under 35 years the presence of oral hairy leukoplakia is a strong predictor of HIV infection (19). Sarcomatosis Kaposi Predilection sites for Kaposi's sarcoma are hard and soft palate, where the lesions are symmetrical, but there are cases affecting the parotid glands and tongue - lesions are asymptomatic bluish-black. Bone lesions may cause swelling of the overlying soft tissue which resembles periapical abscess (15). Periodontal diseases Gingivitis associated with AIDS is described as linear gingival erythema, which bleeds easily and has a small red lesions around marginal edge of the gums and alveolar mucosa. Chronic gingivitis is the most common disease in HIV-infected and AIDS patients (43.8%). Clear improvement of gingival inflammation was seen in 78.2% of patients following a physical therapy (9). 15% of HIV-positive in South Africa manifested ulcerative gingivitis (1). Hodgkin's B- cell lymphoma It represents as quick augmentation is soft tissue mass. Overlying mucosa stay intact. The tumor has a thick consistency - at palpation the feeling is like "fish 76 meat", do not have characteristic hardness "like stone" as in cutaneous carcinomas (15). Herpes simplex virus (Herpes simplex virus, HSV) Herpes simplex cheilitis and herpes simplex stomatitis are very common in the early stages of HIV-infection, but only 6% of chronic patients in Brazil (5) and 7.4% in Cuba have manifestations (3). Cytomegalovirus (CMV) Oral findings in cytomegalovirus are represented by deep ulcers on the lips, tongue, pharynx or oral mucosa. Cytomegalovirus infection often is a reason for xerostomia (8). Human papilloma virus (HPV) It occurs with multiple warts (pink lesions with papillary surface − a type of cabbage) with predilection sites in the median line of hard and soft palate, gingiva (15). Atypical ulcerations In healthy subjects, aphthous ulcers usually appear only on the nonkeratinized surfaces in the mouth, while in immunocompromised patients (including those with AIDS), these ulcers can occur anywhere. In HIV patients aphthous ulcers are very painful, surrounded by red flare and the size is greater than 1 cm in diameter. Unhealed ulcers in HIV patients may result in generalized aphthous stomatitis, infections (tuberculosis, herpes simplex type I, cytomegalovirus) or neoplasm. Ulceration can occur as a result of acquired neutropenia. The incidence of aphthosus lesions in Brazil and Cuba since 2000 is 5-6% of infected patients (3, 5). Molluscum contagiosum is a viral infection of the skin, sometimes of the mucous membranes, often occurring in HIV-positive patients. It is characterized by small pearls, unilaterally arranged papules with a predilection spot eyelids (15). Seborrheic dermatitis is often localized on the scalp and face. Lesions are white scaly patches or spots, there may be an element of erythema or inflammation (15). Bacillary angiomatosis is associated with bacteria of the genus Bartonella. It occurs on the face as a subcutaneous nodule or as a bud (15). Combinations of oral manifestations such as angular cheilitis and hairy leukoplakia, and angular cheilitis and pseudomembranous candidiasis, candidiasis pseudomembranous and hairy leukoplakia are considered pathognomonic for HIV (1). Other lesions associated with HIV and AIDS are melanotic hyperpigmentation, second in frequency of the most common oral manifestation in India with an incidence of 34.6% (19) and 18.3% in Nigeria (20). In China in 14.8% of infected is observed ulcerative (aphthous) stomatitis, keratosis or pyogenic granuloma (3, 6, 12, 14, 17, 21). Oral lesions which help for disease monitoring are oral candidiasis and hairy leukoplakia (4, 10, 14, 15, 16). Such manifestations 6 months after starting treatment for AIDS correspond to still low level of CD4 + T-cells. Candidiasis seems to be a better predictor of non-immune and viral response to treatment (10). According to some authors candidiasis remains most frequent (46%) in the absence of recovery of immune competence (14). If candidiasis continues to manifest in treated patients, most probably there is a problem of patient adherence or a lack of effect could be speculated (4). HIV - ANTIRETROVIRAL THERAPY − modern therapy lines and adverse events with oral localization. Antiretroviral therapy does not destroy the virus of HIV. However, it delays the development of infection. The introduction of powerful treatment change the clinical status of the normal lesions and others, specific to antiretroviral treatment appear occur in oral cavity, such as: • oral lesions; • changes in taste; • xerostomia. During the treatment it must be counted also parotid glands enlargement, observed in 60% of cases with recovery of immune competence (inflammatory syndrome restoration of immune competence), 3 months after highly active antiretroviral therapy (14). 77 Oral lesions Oral candidiasis Linear gingival erythema Hairy leucoplakia NUG Treatment Comments Local therapy Nystatin oral gel every 6-8h, for 10-14 days Nystatin cream every 12h, for 10-14 days BioGaia prodentis – 1 tabls. After teeth brushing morning and evening for about 30 days. Systemic therapy Nystatin tabl. 400 000 – 600 000 IU every 6h Different forms of candidiasis may exist simultaneously; Hyperplastic candidiasis require systemic treatment; Ketoconazole 200-400 mg daily Fluconazole 50-100 mg daily Itraconazole 200 mg daily, for 7 days Amphotericin B 10 mg every 6h for 10 days Ketoconazole can interact with other drugs, metabolised CYP P450 3A4 (Lopinavir, Ritonavir); Amphotericin B is a drug of choice in azoleresistant infections. It could be applied locally; Prophylaxis Fluconazole 100 mg daily, prolonged treatment BioGaia prodentis lozenges – 1 tablet after teeth brushing morning and evening for about 30 days. Long-term concomitant treatment with local fluoride is needed in order to counteract the sugar in some antifungal agents; Dentures should be removed during treatment; Local therapy Scaling and root surface Chlorhexidine gluconatе solution 30 sec, each 12h Local therapy Podophyllin resins 1–2 applications on the affected areas every 2 week Retinol Surgical removal Systemic treatment Acyclovir 800 mg each 4–6h for 14 days Famciclovir 500 mg each 8h for 5–10 days Valacyclovir 1000 mg each 8h for 5–10 days Local therapy Lesions cleaning Prophylaxis recommended with a brush, dental floss and rinse; The use of antifungal agents may be useful; Washing with iodine solutions Chlorhexidine gluconatе – rinse each 12 h After treatment discontinuations, recurrences occur; Changes disappearance was observed in Zidovudine tretament; Long-term use of Chlorhexidine causes teeth color changes, tongue, the filling, taste changes, desquamation of the epithelium and inflammation; Systemic treatment Metrоnidazole 250 mg each 8h or 500 mg each 12h for 7-10 days Clindamycin 150 mg each 6h or 300 mg each 8h Metrоnidazole should not be co-administrated for 7 days with Didanosine or Zalcitabine because of peripheral neuropathy aggravation Necrotizing Amoxicillin clavunate 500 mg each 12h for 7 stomatitis days Table 1: Treatment of oral lesions associated with HIV-infection NUP 78 Oral lesions Angular cheilitis HSV Treatment Local therapy Nystatin – Triamcinilone ointment after meals and at bedtime Clotrimazole 1 % cream Micinazole 2% cream each 12h for 1–2 weeks BioGaia prodentis lozenges – 1 tablet after teeth brushing morning and evening for about 30 days. Systemic treatment Acyclovir 800 mg every 4h for 10 days Isoprinosine 50mg/kg for 10-14 days In resistant infections Foscarnet 24–40 mg/kg each 8h Comments Lesions heal slowly because of the frequent opening of the mouth; Foscarnet is the drug of choice for Acyclovirresistant infections; When taking Acyclovir plenty of water should be drunk; Topical treatment for labial and perioral herpes can be applied; Gancyclovir, Valacyclovir or Famciclovir could be also administrated; Local therapy It is recommended that good oral hygiene and food intake of sugar to prevent caries development; Rinse with liquids with high alcohol content should be avoided due to dryness of mucous membranes; Xerostomia Parotid gland enlargement Oral ulcers (recurrent aphthae) Oral verruca Chewing or sucking on sugar-free candy Frequent sips of water Artificial saliva Fluoride BioGaia prodentis lozenges – 1 tablet after teeth brushing morning and evening for about 30 days. Systemic treatment Pilocarpine 5 mg – 7,5 mg p.o. every 8h before meals Systemic treatment NSAIDs Analgetics Antibiotics Corticosteroids Local therapy Аloclair – spray or gel Gengigel – gel Triamcinolone pasta with Carboxymethilcellulose Betamethasone 0,5 mg in 10 ml water for mouth rinse every 4h Betamethasone-spray Fluocinoide pasta each 4h Dexamethasone elixir for mouth rinse Systemic treatment Prednisone 30-40 mg/d with dose-decreasing for a mouth Thalidomide 200 mg daily – in resistant to local treatment Local therapy Podophyllin resins 1-2 applications on the affected areas each 6h for long-term Surgical Laser ablation Cryotherapy Systemic treatment Cimetidine - 600 mg each 6h, for months Isoprinosine 500 mg/kg, for 14 consecutive days, for 6 consecutive months Interferone alfa – 3 millions weekly for several weeks Table 15: Oral lesions treatment, associate with HIV Surgical removal for aesthetic reasons may be needed; Major aphthous ulcers usually require systemic steroids; Aphthous ulcers are exacerbated under stress; Fe, folic acid and vitamin В 12 to be examined; Dexametasone can be used in the presence of multiple ulcers; Thalidomide should be applied only on severe and frequent reсurrences It is not applied in pregnancy; Frequent recurrences; Combination treatment should be discussed; 79 Role of dental practitioner in oral lesions diagnosis and therapy in hiv-positive patients Detailed examination of the oral cavity should be an essential element of the primary and secondary visits of all HIV-infected patients since more than 1/3 of them do not discuss their oral health at the first contact with health professionals and do not disclose or even suspect the presence of typical oral lesions associated with disease. M. Pereyra et al. reported that over 90% of HIVinfected have at least one oral manifestation of the disease and believe that clinically significant lesions require adequate treatment (16). Other studies focus on oral health of infected subjects − dental status, oral hygiene level, etc. In 2010, A. Santo and partners present the dental status of 101 Portuguese infected with HIV, aged 22-71 years. The mean DMFT index was 16.44 ± 8.42. Greater need for dental surgery had those with index DMFT> 17 and those who are HIV-positive more than five years (18). In long-term follow-up of oral health quality of life of women infected with HIV, and those at risk of infection is found that it is with about 10% worse. Affected quality of life rather is associated with the condition of teeth, the presence of periodontal disease, smoking and cocaine use, but not to the infection itself (11). The role of the dental practitioner goes in two directions: on one hand in the diagnosis of oral signs, and on the other - in their proper response, as changes in the mouth cause additional discomfort for patients and worsen their quality of life. Modern recommended therapeutic protocols for treatment of oral lesions in HIV-patients are presented in Table 1 and 2. COMMENT: Literature data indicate that the percentage of HIV-positive individuals with at least one manifestation of the disease in the oral cavity is up to 90%. These facts determine the important place of the dental practitioner in the team of professionals monitoring these patients. We would like to emphasize that the detailed examination of the oral cavity should be included in the initial, primary review of the patient and should be also repeated in each of the following visits in all HIV-infected. Dental practitioner should not only recognize and diagnose the typical oral manifestations of the disease, but he should also give recommendations for dental health improvement of these individuals and to be able to treat the manifestations in the oral cavity. Dental practitioner should be aware that the dynamics of oral lesions in order therapy to be properly monitored. It will be of a great help not only to dental practitioners, but also to the patients, a specialized dental clinical center to be established for primary dental examinations and treatment of patients at risk. On the one hand, dental specialists will be more competent giving closer advices to HIV-infected and other patients will know where to find adequate care for their condition. Also negative speculations will be avoided while these individuals hide their illness because of fear treatment to be refused. 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