症例の概要: 患者は60歳の男性で上顎右側ブリッジの動揺を訴えて来院した.(7) 6 (5) 432 (1)(1) ブリッジ脱離, 5歯根破折と診断した.432部に対してミニSGのアタッチメント装置を用いた可撤性ブリッジによる補綴治療を行い, 5年経過するが経過は良好であった.
考察: 脱離したブリッジの状況から, 固定性ブリッジでは側方力に耐えることが困難であると判断した.また, アタッチメント装着により, 機能的な咬合の安定が図られ, 良好な経過が得られていると思われる.
結論: 本症例では, アタッチメントを使用することによって装着感のよい可撤性ブリッジとなり, 患者からも十分満足が得られ, 機能的にも良好な結果が得られた.

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症例の概要: 交通外傷による歯槽骨および歯の欠損を1℃ アタッチメント応用部分床義歯で補綴した.
考察: 前歯部にクラスプが使用されていないこと, 義歯の維持力の不足や使用時の疼痛もなく, 着脱が容易なことから審美性および機能性に対する患者の十分な満足が得られた.
結論: 前歯部欠損症例において, 比較的小型でクラスプに比べ審美性の良いアタッチメントを用いたことで患者の十分な満足を得ることができた.また経過が良好なことから, 前歯部欠損症例に対してI-Cアタッチメントが有効使用できることがわかった.

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インプラントを主体とするブリッジにて補綴を考える場合, できるだけ自分の歯を残したいという患者の希望を受け入れることにより, 少数残存歯とインプラントが混在する歯列となり, 補綴設計に苦慮することが多い.このようなケースに対して, エレクトロフォーミングとハイブリッドセラミックスを併用したブリッジにて対応し良好な結果が得られたので報告する.
患者は52歳女性で, 上顎前歯ブリッジの動揺と上顎臼歯欠損部へのインプラント治療を希望して来院した.初診時診査より上顎における保存可能な歯は14, 12, 23と診断.そこで17, 15, 11, 22, 24, 26, 27部インプラントと残存歯を支台とするエレクトロフォーミングとハイブリッドセラミックスを併用した術者可徹式ブリッジにより補綴治療を行った.現在治療終了後2年を経過しているにすぎないが, 良好な結果が得られている.この方法はロングスパンの症例においても精度の高い補綴物を製作できることが最大の利点と思われるが, 今回のような天然歯とインプラントが混在する症例に対しても有効な方法であると思われる.

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Magnetic attachments are third-generation attachments with various characteristics, and their application to implant-supported dentures has been attempted. This attachment is useful in overdentures for difficult cases such as edentulous jaw, cleft palate, and remarkable defect of jawbone.
This report describes an implant overdenture with milling bar attachment made of a goldplatinum alloy that has magnet keepers on the top face. The denture has a titanium frame in the permanent resin baseplate. This attachment has only retentive force, and support and bracing force are demonstrated with the milling bar.
We have treated 20 cases with this type of denture in 6 years and there was no experience of disintegrated implant, broken bar or remade denture. The advantages of this method based on our clinical experiences are reliable occlusal registration because of the ease of checking the metal frame adaptation on the bar, sufficient support with rigid bar, and easy removal for aged and/or handicapped patients, as well as ease and reliability of repair and relining.

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Purpose: We report that a mentally disabled patient's masticatory function and esthetics were improved by applying the implant overdenture system by using a magnetic attachment.
Case: The patient was a 56-year-old female. The chief complaint was disturbance of masticatory function because of ill-fitting of the upper jaw denture. The case was complicated because the patient was seriously mentally disabled and attended an institution for the mentally disabled in daily life. Oral findings were edentulous upper jaw 2 years ago and the lower jaw had only 2 teeth.The alveolar bone of the upper jaw showed remarkable bone resorption and the tongue and lips showed extramovement.
Operation and Course: We performed surgical insertion of 7 ITI^® implants around the 832｜2378 regions under intravenous sedation. Six months later, we carried out a second operation to implant the Platon^® magnetic head system, and then completed the upper overdenture without palatal base by using the magnet of Hitachi^® High Colex. After completing the overdenture, the patient showed remarkably improved masticatory function and esthetics, and reduced extra-movement of the tongue and lips. We are now performing a regular check-up every three months.
Discussion and Conclusion: We found that implantation for the mentally disabled patient involved many difficult factors such as whether the implant was done by surgical operation or not, and maintenance of oral condition was poor because of poor oral hygiene. In this case, the implant overdenture system by using magnetic attachment was shown to improve QOL for the mentally disabled patient and was very useful.

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Recently, magnetic attachments for implants have been reported to be useful. However, keepers of magnetic attachments have produced metal artifacts on magnetic resonance (MR) imaging in the head and neck regions. The purpose of this study was to evaluate metal artifacts on MR imaging using Magnetic Attachments of a Cap Shape (MACS) removable keepers, in a phantom study and in clinical cases.
The following results were obtained:
1. In the phantom study, the dimensions of metal artifacts were 11.3 centimeters with a keeper,and almost none without a keeper.
2. In clinical case, diagnostic imaging in the head and neck regions was impossible with keepers, and possible without keepers. These results suggested that MACS is useful for MR imaging in the oral region, because it has a removable keeper.

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The aim of this study was to evaluate the clinical retention force of implant magnetic dentures. Dental implants for a demonstration were implanted into a model of an edentulous jaw, and a maxillary roofless denture, on which a magnetic attachment was placed, was made. The magnetic attachments were placed at the positions corresponding to 17, 14, 12, 22, 24, and 27 in the FDI dental formula. Three types of magnetic attachment, i. e., flat-type, cushion-type and dome-type, were used. A tensile load was applied at one of two positions to remove the denture from the model: one was the center of both maxillary center incisors (front center), and the other was the barycenter of the positions of 6 magnetic attachments (barycenter). The effects of the locations of magnetic attachments, types of attachment, and positions of applying tensile load on the retention force were investigated, and the following conclusions were drawn.
1. The maximum retention force increased with the number of magnetic attachments, regardless of the tensile load application position, and the effect of the type of magnetic attachment in descending order was flat-type, cushion-type and dome-type.
2. The two-factor interaction between magnetic attachment location and type on retention force indicated that the difference among magnetic attachment types was small if the number of magnetic attachments was small, but the difference between the flat-type or the cushion-type and the dome-type became significantly large as the number of magnetic attachments increased. This tendency was more pronounced when the number of magnetic attachments was greater than four.
3. The two-factor interaction between magnetic attachment location and tensile load application position indicated that the retention force of the barycenter was greater than that of the front center in general, but the difference between the retention force of the two positions became significantly large as the number of magnetic attachments increased.
4. The two-factor interaction between the type of magnetic attachment and tensile load application position indicated that the retention force decreased in descending order of flat-type, cushion-type and dome-type, and the difference became large when the tensile load application position was the barycenter.
5. The retention force was strongly positively correlated with the area surrounded by magnetic attachments when the tensile load was applied to the barycenter, and increased with an increase of the area, although the correlation was poor when the tensile load application position was the front center.

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The use of magnetic attachments in implant-supported overdentures has been attempted in a variety of forms. Magnetic attachments for two implants inserted in the canines area between both mentale foramen in the edentulous mandible in particular are highly regarded for their simplicity and usefulness. Nevertheless, the distribution of force acting on the residual ridge differs depending on the shape of the upper surface and has yet to be clarified.
To clarify the optimal shape of the upper surface for attachment, we geometrically analyzed the compression force acting on the residual ridge, bearing capacity of the residual ridge, and the effects of two types of upper surfaces, a dome shape and a reverse dome shape. We inserted an implant fixture in the portion corresponding to the canines between both foramen mentale in a standard model of the edentulous mandible and attached a dome attachment. We fabricated a plaster model and measured the slope and area of the residual ridge. In accordance with Young's modules, we calculated the compression force on the residual ridge mucosa by the denture with respect to a fixed amount of sinking and determined the ratio of the supportable occlusal force as support efficiency.
In addition, symmetrical to the dome shape, a reverse dome shape with the same radius of curvature was analyzed in a similar manner.
As a result, the dome shape was able to support occlusal force 10.7% greater than the reverse dome shape at a fixed amount of sinking. With respect to fixed occlusal force, the dome shape had 11.1% less sinking of the residual ridge mucosa than the reverse dome shape. In addition, the dome shape displayed maximum support efficiency at the portion distal to the first molar, and support capacity was evenly distributed. In contrast, the reverse dome shape displayed maximum support efficiency at the portion corresponding to the second premolar, and the range of support efficiency tended to be concentrated.
These results suggest that the dome shape is superior to the reverse dome shape by effectively and evenly bearing a large occlusal force on the residual ridge mucosa.

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目的: 日常の臨床において歯冠補綴物の脱離がみられるが, そのほとんどがポストを有する鋳造築造体からの脱離である. 原因については, ポストの形態や応力分布など力学的観点からの究明が多い. 接着性からの検討も行われているがわずかであり, 歯冠象牙質を対象としているのが現状である. そこで今回は, 築造体の脱離の原因を歯根象牙質とレジンセメントとの接着性から究明するため, その第一歩として歯冠および歯根象牙質に対するレジンセメントとの接着性について検討を行った.
方法: 被着体は, 抜歯直後冷凍保存した人歯を使用直前に自然解凍し, #1000の耐水紙にて露出させた歯冠および歯根象牙質を用いた. 歯冠および歯根象牙質に対する4種の市販レジンセメントとの接着性, 前処理材処理後およびレジンセメント接着後のレジンタグの状態を電子顕微鏡によって観察を行った.
結果: 4種のレジンセメントのすべてにおいて, 歯冠象牙質に対する接着性が歯根象牙質に対する接着性より高かった. また, 前処理材によるスメア層の除去効果は歯冠において顕著であった. さらに, 歯冠象牙質において長いレジンタグが存在していることが確認できた.
結論: 歯根象牙質におけるスメア層の処理効果を歯冠象牙質と同程度に行うことが, 歯根象牙質に対するレジンセメントの接着性を高める一因となりうることが示唆された.

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上顎洞底粘膜挙上術（サイナスリフト）において,上顎骨が約 1～2mm（分類SA ４）の挙上は洞底粘膜や毋床骨からの血流は乏しく,粉砕自家骨を用いても充分な骨量を確保できない場合がある.
臨床医として施行可能な範囲で,組織工学の原則である腸骨より体性幹細胞,足場として CHA（carbonate apatite）と自家粉砕骨を混ぜたもの,成長因子としてAPC-PRP（Auto Platelet concentration Platelet Rich Plasma ）の３要素を用いて,サイナスリフトを施行した.４ヶ月後,口腔インプラントを埋入時に内径2～3mmのフライスドリルを用いてD2程度に造成された新生骨をブロック状で採取することが可能であったため,これを用いて組織学的検討をおこなった.
最も骨造成を必要とした|5部の成熟骨化率は40.15％,新生骨化率は6.40％,骨占有率は46.75％以上の石灰化があった.骨髄相当部では残留していた一部のCHAと骨の間においては,血管系は少ないものの,CHAは一部吸収され,その周囲には整然と骨芽細胞様細胞が配列されている組織観察が得られた.インプラント上部構造装着後,15ヶ月経過するが予後は良好である.
以上のことからコラーゲン？T型,結晶核として Ca²⁺,CO₃^2-,PO₄^3-等のイオンの介在の可能性,CHAによるpHの調整,骨造成蛋白の発現の制御を検討した.

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