Reply to 陳明時教授

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Reply to 陳明時教授
鄭光顯 醫師
▌台北醫學大學牙醫學士
▌台北市鄭牙醫診所
▌假牙膺復，顳顎關節障礙，口腔、
顏面、頭頸疼痛，賽斯學派身心靈
健康統合治療診所
筆者在新北市牙醫NO: 220，2013/5的一篇文章:「Implantomania? Prosthodontics at the crossroads
」，承蒙陳教授的注意，謂筆者的文章他大概看過，來電要筆者看看他的 restorative work on the issue
of implants and/or teeth supported and attach-ments retained Overdenture。主要是筆者文中涉及談論
implant retained overdenture 的問題，剛好陳教授在這方面的議題著墨不少，其觀點，診斷， treatment
protocol，讓人印象深刻。
筆者在TMDs、orofacial pain、occlusion、conventional partial，fixed，complete denture prosthodontics，賽斯身心健康療法的涉獵較多。「Implantomania? Prosthodontics at the crossroads」一文是根據
Dr. George A. Zarb，在一篇 prosthodontics journal 的文章，提出各種面向的看法及呼籲，認為implant
dentistry 應是 adjunctive in nature，其他有關 implant 的各種 issues，筆者亦引用文獻的多數實證資
料及其他各類文章作者的看法。哦！其中仔細再看看筆者的描述，也覺得不夠完善。應該是：Chales
Goodacre在 dental Implant complications 中的一個章節涉及 implant retained overdenture 說：「all
implant overdenture attachments lose their retentiveness as wear occur ……The same factor cause
overdenture attachments to fracture, which then need to be replaced, all prostheses need to be relined
as changes usually occur in the residual ridges, The period of time it for bone resorption to progress to
a degree where a reline is indicated varies between patients. The timing has also been attributed to the
length of time the patient has been edentulous, with more change occurring in the early years following
tooth loss, when the implant were placed into the anterior aspect of edentulous mandibles and implant
overdentures-fabricated for patients exhibited greater annual posterior ridge resorption was not observed
in patient who were edentulous for periods greater than ten years. 」
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Patient with parafunctional habits place heavy occlusal forces on the overdenture which are then
transferred to the residual ridge, thereby increasing the bone resorption and for reline. In addition,
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patient with implants develop higher occlusal force than complete denture patients, The ability to chew
with greater rigor is one of the benefits of an implant supported or refained prosthesis and Therefore
it is likely that implant overdentures that have a larger area of residual ridge coverage posteriorly will
need reline.
With patients who have high functional expectations from their prosthesis or who have exhibited
heavy occlusal force on their previous complete dentures, it is advisable to increase the number of
implants placed and also increase the number of retentive mechanisms present. In this manner, the
forces can be shared by multiple atlachments decreasing the need for adjustment and replacement.
It addition, more of residual ridge area will be covered by implants and the associated retentive
devices, decreasing the area of residual ridge that is contacted by the prosthesis base, The increase
bone resorption recorded in patient with implant overdenture who have been edentulous for shorter
periods led to a group of authors to propose that implant overdenture should be cautiously evaluated in
younger patients. Another author ( Sadowsky, ST mandibular implant retained overdenture: a literature
review. J Prosthet pant 2001; 86: 468-73) in the literature review, suggests that overdentures may not
be the treatment of choice in younger patients or those who have edentulous for shorter periods. A
mandibular implant-supported fixed complete denture may provide better bone preservation than on
implant overdenture for these patients.
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當然，根據 The international symposium“Towards Optimized Manage ment of the edentulous
predicament”，已經 established that mandible implant retained-overdentures could be optimum
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standard of treatment for the edentulous mandible。其優點包括：1. functional load distribution in the
mucosa, and therefore on the bone, is wilder than thaf obtained by the bar retention。2. separated
implants do not interfere with the physiologic deformation of the mandible dunng function, interference
occurs when uniting the implants with a bar, The deformation of the mandible during funcfion could
be important in relation to remodeling。3. residual oral structures are maintained in good health over
time。4. oral function is improved, Tissue reaction to functional loads demonstrates improved tropism
the mucooa covering the distal edentulous ridges。5. sensory in the mucosa increase in number。6.
physiologic behavior of innervations is more similar to that in dentate patient。7. increase expression of
cytokines stimulate the osteogenic activity of fibroblasts of the mucosa covering the edentulous ridges。
但在筆者的文章所討論的主要重點並非這些。
從另一個面向，若是以較省時、較簡單、較省錢、較安全，以病人利益為導向，同樣達成 success
criteria的治療目的的治療原則。Dental implant treatment, with respect to some complications, their
incidence of occurrence has not been well documented, For eample, the prevalence of peri-implantitis
was unknown until recently because most papers
reviewed in the state of the science on implant
Dentistry「did not include-this parameter, Therefore,
many patient and clinicians were not aware of this
before accepting the implant option. In two crosssectional studies reported by Lindhe and meyle,
the incidence of peri-implantits in the two group of
patients was 28％ and ≧ 56％ of the subjects and
in 12％ and 43％ of the implant site, respectively,
Therefore almost 25-50％ patients receiving implants
experienced this complication。」
則病人選擇 implant 為 rehabilitation 時，應告知
這些風險，而非 quasi-panacea treatment status for
partially and completely edentulous patient。最近
focal infection theory 的復活，也使得牙醫師不得不
注意植體的選擇及牙周病的防治。蓋長期的臨床研究
已知道 implant 的 composition, thread configuration,
surface topography 皆會影響其品質。流行病學的研
究牙周病菌和其產物，例如 LPS (Lipopoly saccharide
)，和一些 pro-inflamatory cytokines，如 INF-α、
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IL-lB、IF-I 和 PGE2，所有這些東西都會跑到身體其他部位影響疾病產生，例如心血管疾病、早產完、
糖尿病、肺部疾病成為獨立的危險因子，一些植體設計容易引起 peri-implantitis 和牙周病控制不好的，
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如上述因果關係成立的話（尚待證據證實，某些已有初步成果），植體的研究與選擇治療更顯得重要。
另在陳教授文章中提及 jaw bone relationship，如圖3 classⅢ病例，上顎完全在下顎舌側達15mm，
lack of anterior protected articulation，包括 canine guidance 及 incisal Guidance 完全不存在。此為
先天缺陷牙醫師毫無能力的看法，筆者有興趣的是，真的為先天缺陷嗎？根據咬合大師 Dawson 的說
法，In severe malretiouships, there is no anterior contact. The usual problem associated with lack of
centric contact is supraerupion of the teeth, This is rarely a problem with anterior crossbites, because
the upper lip substitutes for the contact and holds the lower feeth from supraerupting. Of course,
Anterior crossbites can not provide anterior guidance for either protrusive or lateral excursions. It does
not however, constitute a problem, prognathic patients do not use protrusive movement, so there in no
need to provide disclusion the posfenior teeth in protrusion, most prognathic patients limit their function
to vertical "chop chop", movements, but it is wise to provide balanclng incline disclusion anyway, The
necessary lift can usually be provided by the working-side inclines, since there is no anterior guidance
to help the posterior teeth, group function of the working inclines is usually the occlusion of choice。
又，陳文談到 abbutment paralleling 的問題，如果
implant body angulation 不像 natural dentition, The
long axis each lower tooth is aligned nearly parallel
to its individual arc of closure around the condyle
axis, and form the curve of spee, but in implant case
no one surgeon who can make so sure that the
placement of implant fixture angulation in any clinical
situation is parallel to its indivisual arc of closure
around the condyle axis, This is particular problematic
in implant prostheses because implant can not
tolerate nonaxial loading that destroy bone around
implants, and damaged fixtures, break screws, and
cause restoration to fail, By the same token, implant
lack mechanoreceptor in the periodontal ligament and
inside dentinal tubule which inheremt in the natural
tooth and without the cushion effect in the periodontal
Ligament of nafural tooth to avoid overload, add
another overload on the implant or implanted
supported restoration itself。是不是也需要考量這些？
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