日補綴会誌 Ann Jpn Prosthodont Soc 10 : 179-189, 2018

依 頼 論 文◆企画：第 126 回学術大会／海外特別講演

Implant therapy in the geriatric patient
Frauke Müller, Dr. med. dent. habil.
University Clinics of Dental Medicine of Geneva, Division of Gerodontology
and Removable Prosthodontics
University Hospitals Geneva, Department of Internal Medicine, Rehabilitation
and Geriatrics, Geneva, Switzerland

会長，Swiss Society for Gerodontology and Special
Care Dentistry の会長（2010 2016 年）を務めました．また歯科インプラント学の分野では，ITI Board of
Directors のメンバーであり，ITI Treatment Guide の中で高齢者へのインプラント治療の章を担当しています．先生がこれまで発表した査読付き学術論文は 140
編，著書は 20 冊を数え，招待講演は 400 回以上に及んでいます．2013 年には，高齢者歯科学分野での功績により，The IADR Distinguished Scientist Award in
Geriatric Oral Research を受賞し，この分野での世界の第一人者であることは今さら贅言を要しません．
Frauke Müller 先生の研究の専門性は，歯科補綴学の基盤の上に，顎口腔機能学や臨床疫学の手法を応用したものです．高齢者の口腔機能，生きがい，栄養などの問題を客観的に評価し，補綴的介入の効果を多角的に分析するという点で，わが国の歯科補綴学と非常に通じるところがあります．
学会で先生と会うたびに，研究についてディスカッションができることが，私にとっても何よりの楽しみです．また，先生のジュネーヴでのスタッフであった Martin Schimmel 先生は，スイスのベルン大学高齢者歯科学の教授となり，近年ジュネーヴとベルンのネットワークによって次々発表される高齢者の咀嚼機
能や補綴治療効果に関するすぐれた論文は，われわれ日本の研究者を大いに刺激してくれています．
口腔機能による高齢者の健康と生きがいの維持・回復は世界的な課題であり，欧州に Frauke Müller 先生という理解しあえるリーダーがいることは，われわ
れにとってたいへん心強いことだと思われます．今後もわが国と欧州の歯科補綴学・高齢者歯科学分野が双方向に交流し切磋琢磨することで，広く世界に貢献することを念じて止みません．

Frauke Müller 先生について
新潟大学医歯学総合研究科
包括歯科補綴学分野 小野高裕
昨年春に横浜で開催された日本補綴歯科学会第 126回学術大会の海外招待講演者として Frauke Müller
先生が招聘され，該博な知識と明晰な論理展開に裏打ちされた講演により，本学会会員に多大な感銘を与えたことは皆様の記憶に新しいところと存じます．大久保大会長よりご指名いただき，講演の座長を務めさせていただいたことは，彼女と長年友誼を交わして来た
私にとってたいへん嬉しいことでした．そして今回，超多忙にも関わらず，その講演の要旨を日本補綴歯科学会誌に寄稿していただくことができましたので，改めて Frauke Müller 先生についてご紹介させていた
だきます．
Frauke Müller 先生は，ドイツのキールの出身で，ボン大学歯学部を卒業し，同大学で Doctor degreeを取得しました．その後，マインツ大学の歯科補綴学講座に移って研鑽を積み，1988 年と 1993 1994 年の二度にわたって英国の London Hospital Medical
College に留学，1996 年にはドイツ語圏の教授資格である Habilitation を取得しました．そして，2003 年にスイスのジュネーヴ大学歯学部の高齢者歯科学・可
撤性歯科補綴学分野の教授に就任し，今日に至っています．
Frauke Müller 先生の国際的な活躍は，日本でも多くの研究者に認知されているところですが，主な役
職をご紹介しますと，まず高齢者歯科学の領域では，European College of Gerodontology (ECG) ならびに
IADR の Geriatric Oral Research Group (GORG) の大

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AuthorFrauke Müller is professor and chair for gerodontology and removable prosthodontics at the University Clinics ofDental Medicine at the University of Geneva, Switzerland
Frauke Müller was born in Kiel, Germany and studied dentistry in Bonn, where she received her Dental and Doctorate
Degree. Until 2003, she worked at the Department of Prosthetic Dentistry of the University of Mainz, Germany
where she received her habilitation (PD). She spend several years at the London Hospital Medical College, England.
Professor Müller is Past-President of the ECG (European College of Gerodontology), the GORG of IADR (Geriatric
Oral Research Group) and the Swiss Society for Gerodontology and Special Care Dentistry (SSGS). Since 2017
she is President of the Prosthodontic Research Group of the IADR. She is member of the ITI Board of Directors(International Team for Implantology) and author of the ITI Treatment Guide no 9 on “Implant therapy in theGeriatric Patient”. Frauke Müller is Associate Editor of Gerodontology and edited the textbook “Oral Healthcare and
The Frail Elder”. In 2013 she was awarded the IADR Distinguished Scientist Award in Geriatric Oral Research. Her
research activity is mainly related to gerodontology, oral function as well as complete and implant prosthodontics.
ABSTRACT                 
evidence to state that the mandibular implant overdenture is a well-established treatment modality, certainly in
non-dependent edentulous individuals, but little is known on the very old and geriatric edentulous patients. They                   dental implants are well documented, elderly adults are often reluctant to agree to an implant insertion, even if costis removed as limiting factor. The main reasons for implant refusal are the fear of surgery and pain. The present
paper describes the use of minimal-invasive and simple treatment concepts for elderly, edentulous patients. It further
highlights possible complications, which may arise with the onset of dependency and/or frailty and advises further       !"        
 

 #      Key words:
Geriatric dentistry, Dental implants, Implant-overdenture

Recent developments ‒ the “new”
edentulous patient
Recent developments indicate an increasing life
expectancy and tooth loss occurring later in life 1, 2).
So what will future “edentulous cases” look like?
Physiological aging is not the only characteristic oflate life; cognitive impairment, frailty and multiple
chronic diseases, as well as the side eﬀects of therelated medications, also become common 3, 4).
Very old and fragile edentulous patients will often
present a considerable challenge to the clinician,as the anatomical conditions are likely to be poor
for gaining denture retention and stability, andmuscle control will have likewise deteriorated.
Side eﬀects from the treatment of chronic conditions such as xerostomia or sensitive mucosa canfurther aﬀect oral comfort and challenge denture

wearing. Beyond the challenges of wearing adenture, clinical procedures can also be more difﬁcult, for example when reduced mobility requires
treating the patient in non-ideal positions or cognitively impaired patients are unable to cooperate
in certain treatment steps such as taking the jaw
relation 5). Thus before beginning long and invasive
treatments, the patientʼs physical tolerance should
be investigated to determine the acceptable treatment burden per session 6).
新 無歯顎患者の動向
近年の平均余命の増進は晩年に歯の欠損を伴うことも示している．同時に歳を重ねるということは全身的障害や認知障害，虚弱などの問題を抱える可能性もあり，高齢無歯顎患者においては義歯の維持，安定を得にくく，治療術式も困難となる．そこで，治療開始前には患者の身体的許容性をよく把握する必要がある．

Implant therapy in the geriatric patient

Denture adaptation
A major challenge arises when existing welladapted dentures have to be replaced because
they are lost or have become unhygienic, worn or
simply insuﬃcient. Learning new motor skills or
adapting existing motor patterns requires neuroplasticity, which may be compromised at a very
high age 7). Therefore the capacity to adapt to a
replacement denture which is diﬀerent in form andfunction may be considerably diminished, which
can cause disappointment for both, the patient
and the dentist 8). Denture retention facilitates
the adaptation process as denture kinetics rely
less on motor skills 9). Another strategy to foster
denture adaptation may be fabricating dentures,
which copy selected features from the existingwell-adapted prostheses by using duplication
techniques.
義歯への適応さまざまな理由により慣れ親しんだ義歯の再製作を要する場合，神経可塑性の低下した高齢者では新しい義歯の形態や機能への適応能力が低下しているため，期待に添えない結果に至る可能性がある．義歯への適応を促す
ための方略としては，咀嚼運動に依存しない義歯の維持力を高めること，既存の慣れ親しんだ義歯の特徴を模倣することが挙げられる．

Implant overdentures
There is suﬃcient evidence to state that themandibular implant overdenture (IOD) is a wellestablished treatment modality, certainly in nondependent edentulous individuals 10, 11). The list offunctional beneﬁts they oﬀer is headed by a substantial increase in chewing eﬃciency, as indicatedby the signiﬁcantly reduced number of chewing
cycles required to obtain a given comminution of astandardized test food 12). This improvement seems
largely independent from the chosen attachment
system or the number of implants used. Along with
the increased chewing eﬃciency, the maximum
bite force is increased after stabilizing a mandibular denture with dental implants 13). A groupof Dutch scientists evaluated chewing eﬃciency

181

with a sieving method in volunteers with diﬀerent
dental states 13). Although they conﬁrmed that their
12 complete denture wearers with signiﬁcantly
resorbed alveolar ridges had the lowest chewing
performance, and that the group of investigated
40 mandibular IOD wearers performed muchbetter, the 24 edentulous patients with little or
no resorption of the ridges outperformed the IOD
patients in the study. Little is known about chewing eﬃciency in geriatric patients, as the limiting
factors may instead be related to general healthand functional decline rather than bite force,
occlusal morphology or denture stability. At any
rate, if an increased chewing eﬃciency is aimed,
worn occlusal surfaced should be replaced by new
denture teeth 14).
CT scans have revealed that edentulous personspresent a smaller cross-sectional area of the masseter and lateral pterygoid muscles and a lower density of the tissues than their age-matched dentate
peers 15). Although with age muscle waste occurs
in all skeletal muscles, the eﬀect might be accelerated when wearing complete dentures as the load
bearing during chewing is limited by pain from thedenture-bearing tissues and denture displacement
when the bolus is placed unfavorably. It is therefore safe to assume that a lack of muscle training
is contributing to the lower masseter muscle bulk
in edentulous individuals. Experimental resistancetraining in elderly adults proved eﬀective inincreasing muscle strength and bulk 16), but data on
the training eﬀect of forceful chewing in elderly
adults remains scarce 17). In a cross sectional study,
the thickness of the masseter muscle was investigated by means of an ultrasound technique 18). Twogroups of patients with implant prostheses, either
ﬁxed or removable, were compared to a group of
conventional complete denture wearers and a fully
dentate control group of similar age. The results
indicate that the mean masseter muscle thicknessof the patients with the implant reconstructions
was greater than in complete denture wearers, butless than in persons with a natural dentition.

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インプラントオーバーデンチャー（IOD）

問題であり，認知機能低下の早期兆候ともいわれる．咀

下顎 IOD は無歯顎者の治療法として確立されており，

嚼効率と体重は直接相関していないように思われるが，

アタッチメントの種類やインプラントの数に依存せず咀

咀嚼効率を維持することにより食事の選択肢が広がり，

嚼能率と最大咬合力が増加する．IOD の咀嚼能率は高

栄養価の高い食物を摂取することで間接的に体重変化と度な顎堤吸収患者よりも高いが，顎堤吸収が軽度な患者関連する可能性がある．食物摂取量の変化には患者自身よりは低いと報告されている．しかし，高齢者では明らの背景（認知機能，食事の嗜好，健康状態など）が大きかでなく人工歯の磨耗も関係する．無歯顎者は咀嚼筋のな役割を果たすので，咀嚼効率の改善だけでは食物摂取

断面と密度が小さく，咀嚼負荷の制限により加齢に伴う量は変化しない．口腔の健康や咀嚼効率は，高齢者の栄筋萎縮が加速する．インプラント補綴装着者の咬筋は全養状態に影響を及ぼす 1 つの尺度にしか過ぎない．

部床義歯装着者より厚く有歯顎者より薄い．

Nutritional intake
Tooth loss is accompanied by a decrease inchewing eﬃciency which goes along with a silent
change in nutritional intake, as the food choice
is adapted to what is feasible to chew 19). Henceedentulous persons tend to consume a diet, which
is low in protein, non-starch polysaccharides,
calcium and vitamins 20). However, Weiss andcoworkers conﬁrmed that a BMI of 28 or above isassociated with a reduced mortality 21). Weight loss
is a critical issue in geriatric care 22) and may evenbe an early sign of cognitive decline 23). Althoughchewing eﬃciency does not seem directly correlated to a patientʼs weight, it may indirectly
contribute towards a better nutritional intake as
it invites a wider food choice and allows eating
unblended meals, which look more appetizing.
Despite these intuitive correlations, improving
chewing eﬃciency as only the measure does notchange dietary intake, as other factors such as
habits, food preference, general health, mobility,
culture, and cooking skills as well as cognitive
impairment and appetite may play a role 24). While
tailored nutritional counseling has been shown toincrease the intake of fruits and vegetables withedentulous patients who were provided replacement dentures 25), oral health and chewing eﬃciency
are only one piece in the puzzle that inﬂuences thenutritional state of elderly individuals.
栄養摂取
歯の喪失による咀嚼効率の低下は，栄養摂取量の低下を招く．このため無歯顎者は各種栄養素の摂取が少なくなる傾向にある．体重減少は，老人医療における重大なPsychosocial beneﬁts of implant
overdentures
The stabilization of mandibular complete dentures by means of osseointegrated implants is oneof the most eﬀective interventions in dentistry. Thisis mainly due to the alleviations of the limitations
in social interactions and psychological well-being
related to tooth loss and its consequences. Qualitative research demonstrates that complete denture
wearers modify their behaviors, as they feel uneasy
smiling or sometimes learn certain techniques to
do so with a hand covering the mouth 26). Implant
overdentures may reduce the patientʼs biggest fear,
which is the loss of denture retention in a public
context revealing that they wear complete dentures. Although complete denture wearers experience a signiﬁcant increase in satisfaction after the
renewal of their conventional dentures 27, 28), thosewith new implant overdentures seem to be evenmore satisﬁed with their prostheses. The latteris reported for randomized controlled research
conditions 29, 30) as well as for a context where thepatient freely chooses his/her treatment option 31).
IOD の心理社会的利益
インプラントによる下顎全部床義歯の安定化は，最も効果的な歯科的介入の一つである．これにより，歯の喪
失およびこれに関連する社会生活や心理面での安定を多く享受できるからである．全部床義歯装着により，大きな笑いをためらうことや口を手で覆って笑うなど，患者は振る舞いを変容させることが報告されている．IOD
装着により，全部床義歯の脱離という患者が最たる不安を軽減できるであろう．無歯顎患者への全部床義歯新製により治療満足度は有意に上昇するが，RCT 研究により，新たに IOD を装着するほうがより高い治療満足度を実感することが報告されている．

Implant therapy in the geriatric patient

Survival and success of implant
overdentures
Systematic reviews on implant survival in patients
aged 65 years or over 32) or 75 years and over 33)
indicated no lower survival rates than in younger
adult cohorts. The majority of studies investigate
mandibular implants placed in the interforaminal
region to retain removable overdentures. Fromthe literature, it seems that neither the number of
implants used nor the attachment system chosenor splinting the implants has a signiﬁcant impact
on the treatment success 34, 35). Treatment concepts
for the maxilla, single implant mandibular overdentures and short or small diameter implants are
to date less well documented. Although immediate,
early and conventional loading protocols of mandibular implant dentures are predictable treatment
modalities, early and conventional loading tended
to reduce failures of osseointegration within theﬁrst year post insertion 36). It can be concluded
that mandibular implant overdentures are a safe
and successful treatment modality, which presents
multiple functional, structural and psychosocial
beneﬁts to the patient.
IOD の生存と成功
65 〜 74 歳の患者群および 75 歳以上の患者群を対象とした文献レビューにより，両群間のインプラントの生存率に差が無いことが示された．またこれらの文献から，
インプラント治療の成功に重大な影響を及ぼす要因は，埋入されたインプラント数でも，使用されたアタッチメ
ントシステムでも無いことも判明した．下顎 IOD に対する治療プロトコルとして即時，早期および通常荷重な

183

clinical trial. Walton and MacEntee 37) reported a
35% refusal rate when recruiting for a study where
2 implants would be placed to retain a lower denture, all at no cost to the patient. Whereas agreeing
to participate in the study was mainly motivatedby functional improvement and comfort, nearly
half of the refusals were related to the surgicalintervention or the perception that implants were
not necessary. There may be several reasonsfor this. Firstly, elderly patients tend to become
more satisﬁed with their dentures, even if they
are according to dental professional criteria insufﬁcient 38). Elderly patients may further have other,more important priorities in their lives, especiallywhen they suﬀer from multiple chronic diseases
and/or they present with severe disabilities. A
recent survey of 92 persons who either lived athome, in a long-term care (LTC) facility or were
hospitalized revealed that a negative attitude seems
related to being a women, the type and quality ofthe denture, having little knowledge of implants
and being hospitalized 39). Ellis et al. 11) undertook aqualitative approach to investigate implant refusal
in dissatisﬁed complete denture wearers. They
conﬁrmed the fear of surgery and post-operative
pain, as well as the perception of inadequacy of
the intervention for a person at an advanced age.
The strategy to allow edentulous individuals to
beneﬁt from oral implants late in life should be
to schedule the intervention when they are not(yet) institutionalized. Their motivation could be
fostered by competent professional informationand minimally invasive surgical procedures.

どが適用されているが，埋入 1 年以内のインテグレー

インプラント治療への不安と拒絶

ションロスの発生に関して，早期および通常荷重のほう

下顎 IOD の有効性は証明されているものの，インプが即時荷重に比べ少ない傾向にある．下顎 IOD は，患

ラントの埋入を拒否する患者は多い．それは外科処置へ者に多くの機能的，構造的および心理社会面での利益をの不安やインプラントの必要性を認識していないことが提供可能な安全かつ予知性の高い治療法であろう．

主な理由である．無歯顎者が将来的にインプラントの恩恵を受けるには，施設に入る前に方針を立てておくことである．専門的な情報を与え，侵襲が少ない手術手技をApprehensions and attitude
Despite the convincing evidence on mandibularimplant overdentures, a great number of patientsrefuse implant placement, even when cost as limiting factor is eliminated within the context of a

提示することで大きな動機づけになる．

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Features of age-adequate dental
prostheses
Removable prostheses for the elderly have tobe designed to meet the conditions of the aged
orofacial system and the functional impairment of
the patient 40). Dentures need to be manufactured
robust, forgiving clumsy handling in patients with
reduced manual dexterity. Loosened ligaments of
the TM joints along with an atrophy of the tuberculum articulare imply the use of denture teeth
with no more than 20 cusp inclination. The issueof reduced motor control, leading to a less precise
closing trajectory of the mandible is best met witha freedom-in-centric occlusal concept. In very oldpatients, who are successfully adapted to a moreanterior position of the mandible, restorations may
copy this “convenience occlusion” rather thanforce the patient in the centric relation. Impaired
vision and tactile sensitivity require well-polisheddenture surfaces, which preclude niches for theretention of food debris and plaque 41). It is further
important that the denture has the highest denture
retention that still allows handling of the prostheses by the patient.
加齢に応じた補綴装置
高齢者の可撤性義歯は，衰えた機能に適応するように設計する．不用意な取り扱いで壊れないようにする．関節周囲組織の老化に応じて人工歯の咬頭傾斜を緩く，運動機能の低下に対応してワイドセントリックを与えるといった配慮が必要である．また，視覚や触覚の衰えた患者では義歯の研磨にはとりわけ注意する．さらに，患者自身が外せる必要十分な維持力の確保も大切である．

Design of implant overdentures
Even careful and systematic appreciation of theliterature in the ﬁeld does not make it possible torecommend an ideal number of implants for mandibular implant overdentures 42). A carefully conducted RCT by Meijer and his group investigatedtreatment concepts using bar-supported mandibular overdentures in edentulous patients 43). Sixty
patients of similar age were randomized into twogroups. They received either two or four implants

10 巻 3 号（2018）

and were followed up for a period of 10 years. No
diﬀerence was found in radiological and clinicalparameters, patient satisfaction and maintenanceneeds. However, analysis of the posterior bone loss
indicated a signiﬁcantly more pronounced atrophy
when only two implants had been placed 44). As thisseemed independent of the peri-implant bone loss,
it may rather be related to the sinking in of theposterior denture saddle under occlusal load. In
young edentates, where chewing muscle atrophy is
not yet clinically relevant, or in cases with a strong
antagonistic dentition, it seems preferable to createa large support area, thus placing four implants
in the canine and second premolar region. Distal
extensions are advisable to enlarge the support
area even further, but often the denture height
is not suﬃcient to accommodate the superstructure. Frequent fractures of these extensions will
be reduced if recent CAD/CAM technologies formilled titanium bars are used 45).
The stronger occlusal load with implant overdentures may also impact the atrophy of the maxillaryridge. Tymstra et al. demonstrated that with both atwo- and four-implant mandibular overdenture themaxillary anterior bone resorption was signiﬁcant
over a 10-year period, whereas in a control groupwith complete denture wearers it was not 46). Whatever the number of implants placed is, it seems
advisable to frequently remount the dentures toavoid anteriorization of the occlusion and/or reline
the mandibular denture when necessary.
The ideal position of two implants would be in
the in the most anterior and most lateral position of
the edentulous mandible. It seems important thatno anterior lever is created, as this might lead to a
rocking movement of the overdenture as the freeend saddles sink into the denture bearing tissues
during the wearing period. When four implants areplaced, the position of the anterior implants shouldbe the same as in a 2-implant overdenture, andthe posterior implants should be placed as distal
as possible, but anterior to the mental foramen 40).
Extensive splinting of implants should be avoided
in the dentulous mandible, as mandibular ﬂexure
may create a certain discomfort for the patient andexpose the implants to uncontrolled forces. Is a

Implant therapy in the geriatric patient

single implant on the mandibular midline suﬃcient
to satisfy the edentulous patient? Indeed, an RCT,
which randomized edentulous participants between
one and two mandibular implants for a mandibularimplant-overdenture, showed a signiﬁcant increasein patient satisfaction in both groups 47). However,already at the 12-month follow-up visit, ﬁve of the
42 patients in the one-implant group shifted fromthe positive half of the VAS scale to the negative
half. Implant survival seems excellent using thistreatment concept although long-term observations of patient-centered and functional outcome
measures scarce 48). It remains to be borne in mind
that the midline suture of the mandible often
presents a midline mandibular lingual canal withblood vessels and nerves, which requires attention
during implant placement 49).
インプラントオーバーデンチャー（IOD）のデザイン
理想的なインプラント本数を推奨することは難しいが，2 本と 4 本インプラントの IOD では X 線，
臨床所見，

185

has to be recommended, allowing for a palatal-freehorse-shoe design, where the implants are placedin the canine region and as close as possible to thechewing center, just mesial of the sinus to avoid
additional surgery. This treatment concept keeps
the phonetic zone free from bulky superstructuresand encourages a natural morphology of the palatal coverage, which in turn facilitates the natural
feel and speech of the patient. A shallow 0.5 mm
deep carved dam helps to avoid food impaction
under the prosthesis. The transition of the palatal
coverage to the natural hard palate should be
fabricated in chrome cast, as this allows a smoothtransition from the natural to the artiﬁcial palate.
Unlike in a palatal band for a partial denture, thistransition is situated in a zone of the palate where
the tongue is in contact during rest; therefore it
seems particularly important to avoid structuresthat invite the initiation of disturbing habits of the
tongue.

患者満足度とメインテナンスの頻度に関して有意な差は

上顎インプラントオーバーデンチャー

認められなかった．しかし，2-IOD において臼歯部顎堤2 本のインプラントでは義歯の動揺を抑えることがでの骨吸収量が有意に多く認められため，若い無歯顎患者

きず，頻繁なリラインが必要となるため，上顎においてにおいてはインプラントを 4 本配置することも考慮した

は 4 本のインプラントによる口蓋を覆わない馬蹄形のほうが良い．その際には，義歯の破折に注意をする必要

オーバーデンチャーが推奨される．埋入位置としては犬がある．下顎 IOD による強い咬合力により，上顎の無歯部および上顎洞のすぐ近心が良い．この治療コンセプ

歯顎顎堤前歯部に骨吸収を生じることがあるので，リマトにより口蓋部を解放することができるため，違和感やウントやリラインを行い咬合の安定を計る必要がある．

発音障害を防ぐことが可能となる．

2 本のインプラントの理想的な位置は，最も前方かつ側方であり，インプラントを支点とした前後的なシーソーのような動きをしない位置にインプラントを配置することが重要である．1 本支持の IOD は良好な患者満足度と生存率を示しているが，長期間の臨床研究報告は十分でない．

Maxillary implant-overdentures
The mucosa covering the hard palate has aconsiderably higher resilience than the one covering the mandibular alveolar ridge; therefore
placing two implants to support an upper implantoverdenture must be discouraged. Very soon, theoverdenture would begin rocking over the implantaxis, thus causing discomfort and a frequent needfor relining. Therefore, a minimum of four implants

Attachment systems
Again, the literature does not conclusively
recommend one ideal attachment system forthe implant-supported overdenture. However, areview of attachment systems by Andreiotelli et al.
summarized the advantages and inconveniencesof some commonly used systems 50). Whereas bar
attachments require a lot of vertical space andcreate high initial fabrication costs, they provide
good retention and require little maintenance. In
contrast, ball attachments use little space, yet theywear and require regular adjustments. Few studies
exist on the use of telescopic crowns and milled
bars, but despite their high fabrication cost they
seem to perfectly satisfy the patient and require

186

日補綴会誌

very little maintenance 51). Magnets, however,seem to provide low retentive forces 50). The rangeof available attachment systems was recently
complemented by the CMLoc (Cendres & Métaux,Biel, Switzerland), where an additional version(CMLoc Flex) allows aligning the attachment axis
by intra-orally. Novel developments also include
the Locator R-Tx (Zest anchors, Carlsbad, US)with an improved design and surface as well as
the Novaloc System with a black carbone surface,which is currently the most wear-resistant surface(Straumann, Basel, Switzerland).

10 巻 3 号（2018）

Figure 1: Age structure of patients having implants placedat the University of Bern (Data from 59))

アタッチメントシステム
IOD における最適なアタッチメントシステムについては未だに結論が出ていない．バーアタッチメントは十分なクリアランスが必要でコストが高いものの，維持力が高く，メインテナンスが少なくて済む．対照的にボールアタッチメントは少ないクリアランスでも可能であるが，調整が必要である．近年，インプラントの埋入角度補正が可能な CMLoc や Locator R-Tx，耐摩耗性に優Figure 2: Two implants the interforaminal area shouldbe placed as anterior and as lateral as possible,
without creating an anterior lever.

れた Novaloc system などが開発されており，選択の幅が広がってきた．

Accompanying the functional decline
Although success and survival rates of dental
implants seem similar in younger and older edentulous patients 32, 52-54), there are certain risk factorsthat are related to aging as well as the onset of
dependency and multi-morbidity 32). Maintaining
good oral hygiene becomes more diﬃcult andis usually less meticulously performed. Little is
known about the prevalence and pathophysiology of peri-implantitis in geriatric patients, but
it seems that the inﬂammatory reaction to an
experimental gingivitis / mucositis is even stronger
around implants than in natural control teeth 55, 56).
Furthermore handling a (retentive) IOD may
exceed the manual force and/or cognitive abilityof the patient as well as the competence of the
caregivers. It must also be born in mind that
denture use as such is less frequent in geriatricpatients in general, but in particular in those whoare cognitively impaired, bedbound, ventilated orundergoing chemotherapy 57). Thus for geriatricFigure 3: In elderly and fragile patients the denture
retention should be chosen (and if
necessary adapted) so that the patient
can manage the denture independently.

patients it seems imperative to add “managementof implant prosthesis and ability to maintain oral
hygiene” to the success criteria mentioned previously. Care should be taken that implant patients
do not “disappear” from the dentistʼs recall system
when they become institutionalized. They should
be closely monitored and if needed the dentureImplant therapy in the geriatric patient

retention should be changed for lighter-retention
systems or the attachments should be removed
to transform the IOD to a conventional complete
denture. This “back-oﬀ” strategy requires visionary
and “reversible” treatment planning when implant
prostheses are planned and fabricated 58).
機能低下に対する配慮
高齢者では IOD の着脱が満足にできない場合がある．
したがって，「インプラント補綴の管理と口腔衛生を維持する能力」を前述の成功基準に加えることが不可欠である．施設に入れられたときに歯科医のリコールシステ
ムから「消えていない」よう注意が必要である．必要に応じて維持力を弱くするか，通常の全部床義歯に変更する必要がある．インプラント補綴が予定される際に，「可逆的」な治療計画が必要である．

Summary and conclusion
Tooth loss will remain a reality in old age, butwill occur later in life, which will confront thedental profession with more complex reduced
partial and complete denture cases. The standardof care in geriatric patients must be adapted tothe patientʼs motivation, functional and cognitive
impairment and medical condition as well as his/her socio-economic context.
結 論
現代の高齢者の欠損補綴診療がさまざまな問題で複雑化・困難化することは避けがたい．高齢患者における標準的治療は，患者のモチベーション，機能障害，認知障
害および医学的状態，さらには経済的状況にも適合させなければならない．
※ 各セクション末に編集委員による要訳を加えました．

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Address for correspondence：Prof Frauke Müller
University Clinics of Dental Medicine of
Geneva, Division of Gerodontology andRemovable Prosthodontics
CMU, 1 rue Michel-Servet
1211 Geneva 4, Switzerland
Email: frauke.mueller@unige.ch