HAS THE PREDICTABILITY OF "OSSEOINTEGRATION" ECLIPSED THAT OF ADVANCED PERIODONTAL TREATMENT? BY DR. WALTON:ORIGINAL+JAPANESE TRANSLATED VERSION
Has the
Predictability of “Osseointegration” Eclipsed That of Advanced Periodontal
Treatment?
“オッセオインテグレーション”の予知性は進行した歯周治療の予知性をしのぐのか？
Author: Terry R.
Walton, BDS, MDSc, MS, FRACDS, FICD
The International Journal of Prosthodontics 2009;22:521-523.
Translation:
Satoshi Kato, DDS
歯科補綴物の長期成積はその支持構造物、つまり歯、インプラント、そしてその組織の健全さに依存する。臨床家の挑戦は患者個人ベースにおける成果を予知することである。しかしながら、これは（成果の予知は）異なる患者、補綴物、そして治療成功の大方を決めることになる術者媒介因子operator parametersの中のほんの一つにすぎない。
一般の人の中の12%程度が進行した歯周治療（初期および継続的）を必要とする中程度そして重篤な歯周病にかかりやすい。これら患者の多くは失った歯の補綴に、妥協的歯周状態を持つ歯を支台とする固定性ブリッジが好まれた。インプラント歯科学の紹介後、これらの歯を救うヒーロー的努力はもはや適正であるとは考えられない。それらはしばしば抜歯されインプラントに交換される。この治療枠組みparadigmの変化は、歯周的妥協歯を支台にすることが減ったために歯牙支持固定性補綴物のfixed dental prostheses(FDPs)の5年から10年の治療成績の改善をもたらした。1
しかしながら、最近の系統的文献総覧recent systemic reviewsからの結論は、臨床家を混乱させるものである。10年経過したインプラントを評価するとき、その寿命は妥協的であるが成功裏に歯周治療された歯の寿命を超えない2；かなり減少しているが健康な歯周組織をもつFDP支台歯の成績を歯周的に問題のない支台歯と好意的（都合よく？）favorably比較している。3
進行した歯周治療成功の予知性とはなにか、そして長期のオッセオインテグレーションの予知性とどのようにして比較するのか？その時ジレンマとなってくる。
Predictability
of Advanced Periodontal Therapies
進行歯周治療の予知性
最低でも15年を超える治療期間の歯周病患者600人における喪失歯数が測定された進行歯周治療の結果が報告された。4 初診時において、16.5%が中程度（ポケット深度4から7mm）として、さらに76.5%が高度進行(ポケット深さ7mmより深い)として分類された。わずか12.6%の患者が喪失歯4から9本、4.2%は10から23歯を喪失しているのであるが、治療結果の予知性predictabilityは困難poorであった。このことが予後の予知性と実際の確認された結果の間を乖離disconnectさせているが、さらに、初診時の第一大臼歯の喪失より他の臨床的遺伝的予知因子はみとめられなかった。
進行した歯周病治療はコストがかかる（金銭的、審美的、満足度、不健全さmorbidity）。系統的文献総覧における歯周的妥協歯の好ましい成績は、十分な口腔衛生、定期的専門的口腔予防清掃prophylaxisと定期健診、そこで必要なら外科的清掃やポケット減少術を行う支持的歯周治療supportive periodontal therapy に喜んで参加する高度に動機付けされた患者に依存する。長期にわたるよい歯周的予後が確認できる歯周的妥協歯の長期保存はまた、骨量の不足を招き結果としてインプラント埋入を困難にすると主張されてきている。
よって、進行した歯周治療は高度に動機付けされた敏感な患者の大多数の特に単根歯を含む領域においては成功しうる。しかしながらこの結果の初診時では予知不能である（Fig 1 から3）。
Predictability
of Osseointegration
オッセオインテグレーションの予後
オッセオインテグレーションの紹介は10年以上にわたる補綴とその支持インプラントの成績報告を伴う科学的厳密さを伴ってきた。これ以後のインプラントに関連した歯科学の発展がそのような厳密さrigorを維持してきたとは必ずしも言い難い。“長期間long term”とは、現在掲載された短期間とされている治療結果の報告でさえ論文の大半においてみられるように、5年以上であると考えられる。さらに、無数の新しいハードウエアとテクニックが、過去の科学的評価の普及を継続する推側により（仮定や推測を基に根拠なく）紹介されてきている。
オッセオインテグレーションの成功の定義は特に骨レベルのしっかりとした維持と関連している。いまだに、論文の大部分はインプラント生存率(これは骨レベル測定とは別である)と平均的辺縁骨喪失mean marginal bone lossを報告している。しかしながら、これは進行した歯周治療の普通に行われている測定（の考え方）と密接に関連している― つまり歯の保存、対、歯の喪失― 骨支持の量とは無関係である。
晩期（2次的）インプラント喪失や生存インプラント周囲の著しい骨喪失を経験する患者群が観察されてきているidentified（Fig 4）。しかしながら、予知できる因子は見当たらず、インプラント周囲炎の病因や過重負担overloadingについて隔たりの大きい不一致が存在する。
歯周病による歯喪失の感受性とインプラント喪失を関連付ける試みは、長期研究における歯の喪失の原因認定の欠如により制限されてきた。歯周病感受性の患者の5年後の臼歯領域において非感受性患者に比べてインプラント喪失の増加と平均的辺縁骨喪失が2mm大きいことが示された。5 著者の経験によるが、1984年から1995年の間に、歯周病により歯を失い無歯顎になったデンチャー不適応患者がインプラント治療を受けたのが僅か18%であった。1996年から2008年の間には、歯周病により歯を失い無歯顎になったデンチャー不適応患者の70%がインプラント治療を受けていた。
この患者ベースの変化は長期オッセオインテグレーションの予知性に影響するのであろうか？ 骨保存のために歯周疾患罹患歯は抜歯すべきなのか、それとも将来インプラントに起こりうる後期(2次的)骨喪失を遅らすように保存すべきであるのか？たとえ長期において“感受性”患者のインプラント周囲の予期せぬ骨喪失があるとしても、口腔の快適性oral comfort、心理的利点のような他の結果成績媒介因子outcome
parametersが、著しい歯周的（しばしば審美的）妥協が必要な歯の残存をこの治療方法(インプラント治療)treatment modalityが凌駕するのであろうか？
Conclusion
結論
オッセオインテグレーションの予知性は歯周病に感受性の高い12%の人々の進行した歯周治療の予知性をしのぐのかという疑問について、現在のところわからないunresolved。
References
1.
Walton
TR. Changes in patient and FDP profiles following the introduction of
osseointegrated implant dentistry in a prosthodontic practice. Int J
Prosthodont. 2009;22:127-135.
2.
Holm-Pederson
P, Lang NP, Muller F. What are the longevities of teeth and oral implants? Clin
Oral Implants Res 2007;18(suppl 3):15-19.
3.
Lulic
M, Brägger U, Lang NP, Zwahlen M, Salvi GE. Ante's (1926) law revisited: a
systematic review on survival rates and complications of fixed dental
prostheses (FDPs) on severely reduced periodontal tissue support. Clin Oral
Implants Res 2007;18 Suppl3:63-72.
4.
Hirsfeld
L, Wasserman B. A long –term survey of tooth loss in 600 treated periodontal
patients. J Periodontol 1978;49:225-237.
5.
Hardt
CR, Gröndahl K, Lekholm U, Wennström JL. Outcome of implant therapy in relation
to experienced loss of periodontal bone support: a retrospective 5- year study.
Clin Oral Implants Res. 2002;13:488-494.
Fig 1 ３１歳女性患者の1989年に撮られたデンタルエックス線写真は進行した歯周疾患による著しい垂直的骨喪失を示している。
Fig 2 1994年オルソパントモグラムは下顎インプラントブリッジと上顎歯の維持を示している。
Fig 3 19年後の患者上顎前歯の状態。4本の残存臼歯は15年後の抜歯され、リムーバル義歯により補綴された。
Fig 4 埋入後18年までの患者のインプラント成績。1994年と1998年の間に1本が喪失し、1998年と2008年の間に２本喪失し、辺縁骨レベルが減少した。
Has the Predictability of
“Osseointegration” Eclipsed
That of Advanced Periodontal
Treatment?
Terry R. Walton, BDS, MDSc, MS, FRACDS, FICD
Clinical Associate Professor, Faculty of Dentistry
University of Sydney, Australia
Fax: 61 2 92650999
Fax: 61 2 92650999
Email: twalton@mail.usyd.edu.au
The long-term outcome of dental prostheses is de-
pendent on the continuing integrity of the supporting
structures, be they teeth, implants, or tissues. The
challenge for the clinician is to predict this outcome on
an individual patient basis. However, this is just one
of several patient, prosthesis, and operator para-
meters that will determine the overall success of the
treatment.
Up to 12% of the general population are suscepti-
ble to a moderate or severe form of periodontal disease
requiring advanced periodontal treatment (initial and
ongoing). Many of these patients with a preference for
a fixed prosthesis to replace lost teeth have potential
abutments that have compromised periodontal sup-
port. Following the introduction of implant dentistry,
“heroic” efforts to save these teeth are no longer con-
sidered appropriate. They are now often extracted and
replaced with implants. This changed paradigm has re-
sulted in less periodontally compromised abutments
being used and an improved 5- to 10-year outcome of
tooth-supported fixed dental prostheses (FDPs).1
However, conclusions from recent systematic re-
views are confusing for the clinician. Oral implants,
when evaluated after 10 years of service, do not sur-
pass the longevity of compromised but successfully
treated natural teeth2; the outcome of FDP tooth abut-
ments with severely reduced but healthy periodontal
support compares favorably with periodontally intact
abutments.3
The dilemma then becomes, what is the predictability of the success of advanced periodontal
treatment and how does it compare with the predictability of osseointegration over the long term?
Predictability of Advanced Periodontal Treatment
The outcome of advanced periodontal therapy mea- sured by the number of lost teeth in 600 periodontal patients over a minimum treatment time of 15 years (median treatment time: 20 years) was reported.4 At ini- tial presentation, 16.5% were classified as moderate in severity (pocket depths 4 to 7 mm) and 76.5% as ad- vanced in severity (pocket depths 7 mm). Although only 12.6% of patients lost 4 to 9 teeth and 4.2% lost 10 to 23 teeth, the predictability of this response to therapy was poor. This “disconnect” between the pre- dictability of the prognosis and the actual outcome has been confirmed, and other than loss of first molars at presentation, no other clinical or genetic predictabil- ity factor has been identified.
Advanced periodontal therapy involves consider- able costs (eg, financial, esthetic, comfort, morbidity). The favorable outcome of periodontally compromised teeth reported in systematic reviews2,3 was contingent on highly motivated patients willing to participate in an accepted protocol of “supportive periodontal therapy” involving efficient oral hygiene, regular professional prophylaxis and review, and where indicated, follow- up surgical debridement and pocket reduction proce- dures. It has also been argued that retaining peridon- tally compromised teeth over an extended period to ascertain their long-term prognosis will subsequently complicate implant placement because of a deficiency in bone quantity.
Thus, advanced periodontal therapy can be suc- cessful in the majority of susceptible and highly moti- vated patients, especially in regions involving single- rooted teeth. However, this outcome is not predictable at initial presentation (Figs 1 to 3).
Predictability of Advanced Periodontal Treatment
The outcome of advanced periodontal therapy mea- sured by the number of lost teeth in 600 periodontal patients over a minimum treatment time of 15 years (median treatment time: 20 years) was reported.4 At ini- tial presentation, 16.5% were classified as moderate in severity (pocket depths 4 to 7 mm) and 76.5% as ad- vanced in severity (pocket depths 7 mm). Although only 12.6% of patients lost 4 to 9 teeth and 4.2% lost 10 to 23 teeth, the predictability of this response to therapy was poor. This “disconnect” between the pre- dictability of the prognosis and the actual outcome has been confirmed, and other than loss of first molars at presentation, no other clinical or genetic predictabil- ity factor has been identified.
Advanced periodontal therapy involves consider- able costs (eg, financial, esthetic, comfort, morbidity). The favorable outcome of periodontally compromised teeth reported in systematic reviews2,3 was contingent on highly motivated patients willing to participate in an accepted protocol of “supportive periodontal therapy” involving efficient oral hygiene, regular professional prophylaxis and review, and where indicated, follow- up surgical debridement and pocket reduction proce- dures. It has also been argued that retaining peridon- tally compromised teeth over an extended period to ascertain their long-term prognosis will subsequently complicate implant placement because of a deficiency in bone quantity.
Thus, advanced periodontal therapy can be suc- cessful in the majority of susceptible and highly moti- vated patients, especially in regions involving single- rooted teeth. However, this outcome is not predictable at initial presentation (Figs 1 to 3).
The introduction of osseointegration was accompanied
by a scientific rigor that documented outcomes of
prostheses and their supporting implants for over 10
years. The subsequent development of implant-related
dentistry has not always maintained such rigor. “Long
term” is considered as being up to 5 years in the ma-
jority of currently published papers, with many report-
ing outcomes over even shorter periods. In addition, a
myriad of new hardware and techniques have been in-
troduced with the presumption that previous scientific
evaluation retains currency.
Success of osseointegration has been defined and
specifically related to the stability of bone levels. Yet,
most papers report implant survival (which is inde-
pendent of bone measurements) and mean marginal
bone loss. However, this does relate closely to the
common measure of success of advanced periodon-
tal treatment—tooth retention verses tooth loss—
irrespective of the quantity of bone support.
Clusters of patients experiencing delayed (sec- ondary) implant loss or severe bone loss around sur- viving implants have been identified (Fig 4). However, no predictability factor has been identified and in- tense disagreement exists as to the etiology involved— peri-implantitis or overloading.
Fig 1 Periapical radiographs of a 31-year-old female patient taken in 1989 showing extensive vertical bone loss as a result of ad- vanced periodontal disease.
Fig 2 Orthopantomogram taken in 1994 showing treatment of the patient involving an implant-supported FDP in the mandible and retention of teeth in the maxilla.
Fig 3 Status of the maxillary anterior teeth of the patient over 19 years. Bone levels have remained relatively stable. The four remaining posterior teeth were extracted after 15 years and replaced with a removable prosthesis.
Fig 4 Implant outcome in the patient up to 18 years post- insertion. Between 1994 and 1998, one implant was lost. Between 1998 and 2008, two implants were lost and marginal bone levels decreased.
Clusters of patients experiencing delayed (sec- ondary) implant loss or severe bone loss around sur- viving implants have been identified (Fig 4). However, no predictability factor has been identified and in- tense disagreement exists as to the etiology involved— peri-implantitis or overloading.
Fig 1 Periapical radiographs of a 31-year-old female patient taken in 1989 showing extensive vertical bone loss as a result of ad- vanced periodontal disease.
Fig 2 Orthopantomogram taken in 1994 showing treatment of the patient involving an implant-supported FDP in the mandible and retention of teeth in the maxilla.
Fig 3 Status of the maxillary anterior teeth of the patient over 19 years. Bone levels have remained relatively stable. The four remaining posterior teeth were extracted after 15 years and replaced with a removable prosthesis.
Fig 4 Implant outcome in the patient up to 18 years post- insertion. Between 1994 and 1998, one implant was lost. Between 1998 and 2008, two implants were lost and marginal bone levels decreased.
Attempts at correlating susceptibility to tooth loss
through periodontal disease with implant loss have
been restricted by the lack of identification of the
cause of tooth loss in long-term studies. In periodon-
tal disease–susceptible patients, an increase in both
implant loss and mean marginal bone loss greater
than 2 mm in posterior segments after 5 years has been
shown compared to nonsusceptible patients.5 It is
the author’s personal experience that between 1984
and 1995, only 18% of edentulous patients treated
with implants due to an inability to tolerate tissue-
supported dentures could be identified as having
lost teeth through periodontal disease. Between 1996
and 2008, 70% of patients treated with full implant-
supported prostheses could be identified as having lost
teeth through periodontal disease.
Will this changed patient base affect the predictability of osseointegration in the long term? Should peri- odontally involved teeth be extracted to preserve bone and facilitate implant placement, or be retained to delay the bone loss that will subsequently occur around the implants? Even if there is an inevitable loss of bone around implants in “susceptible” patients in the long term, do other outcome parameters such as overall oral comfort and psychosocial benefits favor this ther- apeutic modality over the retention of significantly pe- riodontally (and often esthetically) compromised teeth?
Will this changed patient base affect the predictability of osseointegration in the long term? Should peri- odontally involved teeth be extracted to preserve bone and facilitate implant placement, or be retained to delay the bone loss that will subsequently occur around the implants? Even if there is an inevitable loss of bone around implants in “susceptible” patients in the long term, do other outcome parameters such as overall oral comfort and psychosocial benefits favor this ther- apeutic modality over the retention of significantly pe- riodontally (and often esthetically) compromised teeth?
Conclusion
The question of whether the predictability of osseoin- tegration has eclipsed that of advanced periodontal treatment for the 12% of the population who are sus- ceptible to periodontal disease is currently unresolved.
References
1. Walton TR. Changes in patient and FDP profiles following the in- troduction of osseointegrated implant dentistry into a prostho- dontic practice. Int J Prosthodont 2009;22:127–135.
2. Holm-Pedersen P, Lang NP, Müller F. What are the longevities of teeth and oral implants? Clin Oral Implants Res 2007;18(suppl 3):15– 19.
3. Lulic M, Brägger U, Lang NP, Zwahlen M, Salvi GE. Ante’s (1926) law revisited: A systematic review on survival rates and compli- cations of fixed dental prostheses (FDPs) on severely reduced pe- riodontal tissue support. Clin Oral Implants Res 2007;18(suppl 3):63–72.
4. Hirshfeld L, Wasserman B. A long-term survey of tooth loss in 600 treated periodontal patients. J Periodontol 1978:49:225–237.
5. Hardt CR, Gröndahl K, Lekholm U, Wennström LJ. Outcome of im-
plant therapy in relation to experienced loss of periodontal bone support: A retrospective 5-year study. Clin Oral Implants Res 2002;13:488–494.
コメント
コメントを投稿