アブストラクト(31巻4号:神奈川歯学)

神奈川歯学

Japanese

Title : 両側遊離端義歯の設計差が支台歯と床下組織の咬合圧配分に及ぼす影響
Subtitle : 原著
Authors : 山内一郎, 神永美穂子, 松尾悦郎
Authors(kana) :
Organization : 神奈川歯科大学有歯顎補綴学講座
Journal : 神奈川歯学
Volume : 31
Number : 4
Page : 350-362
Year/Month : 1997 / 3
Article : 原著
Publisher : 神奈川歯科大学学会
Abstract : 「緒言」 パーシャルデンチャー設計の困難性は, 機能力の負担上から考えた場合, 全く性質の異なる残存歯と床下組織に支持, 維持ならびに均衡の役割を求めなければならないことにある. 支台歯と粘膜の被圧変位性には大きな差があり, 両者に対して適切な力の配分を考えた設計でなければ, 支台歯および顎堤の保全が図れない危険性がある. さらに, 遊離端欠損症例では, 欠損の一端のみに支台歯が存在するため, 義歯の動態は特異的となり, 支台歯に負担過重を生じやすいことが指摘されている. したがって, このような義歯設計にあたっては, 支台歯の負担軽減と義歯の安定という相反する問題に対処するための方策を理論的に検討することが重要である. 近年, Konuskronen-teleskopeに代表される, 支台歯に強く咬合力負担を求めて義歯の安定を考えたrigid support(以下, リジッドサポート)が支持される傾向にある.
Practice : 歯科学
Keywords : RPI支台装置, 振動解析, 応力解析

English

Title : A Study on the Occlusal Force Distribution to the Abutment Teeth and Supporting Structures due to the Design of Bilateral Distal Extension Dentures
Subtitle : Original article
Authors : Ichiro YAMAUCHI, Mihoko KAMINAGA, Etsuro Matsuo
Authors(kana) :
Organization : Department of Partial Denture Prosthodontics, Kanagawa Dental College
Journal : Kanagawa Shigaku
Volume : 31
Number : 4
Page : 350-362
Year/Month : 1997 / 3
Article : Original article
Publisher : Kanagawa Odontological Society
Abstract : Abstract : After extraction of teeth, the loss of their function has to be compensated by not only the remaining teeth but the residual ridge as well, which is not essentially a portion of the structure supposed to sustain the occlusal force. However, there is a wide difference in tissue displaceability between teeth and the mucous membrane so that it is not easy to design and fabricate an appropriate partial denture. The inadequate allocation of the occlusal force between the abutment teeth and the supporting structure results in overload to the abutment teeth, which induces various types of disorder such as an increase in mobility, alveolar bone resorption, and temporomandibular joint diseases. In the present study, we performed stress and vibration analyses to clarify how the occlusal force is apportioned between the abutment teeth and the supporting structure, using a suprabulge type Akers clasp, and two infrabulge types of RPI retainer, one being the Kratochvil type and the other, the Krol type, designed as standard clasp for retaining bilateral distal extension dentures. A summary of our findings is as follows : 1. The Akers clasp acted to resist occlusal forces mainly via supporting teeth, thus showing a tendency to cause the abutment teeth to incline distally. 2. In the RPI retainers, the partial denture sank in commensuration with the displacement of the mucous membrane and mesial rest seems to distribute forces exerted on the mucosa. 3. Vibration analysis showed that the ratio of tooth-supported forces and mucosa-supported forces was 1 : 0.57~0.75 for the Akers type, 1 : 0.83~1.08 for the Kratochvil type and 1 : 1.02~1.30 for the Krol type. 4. The two RPI retainers have different concepts. The results obtained in the present study indicate that the Kratochvil type is designed on the basis of the ridge-supported concept and the Krol type is the flexible-supported concept.
Practice : Dentistry
Keywords :