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Stress Analysis of Abutments with Reduced Periodontal support of RPDs.

减少 RPD 牙周支持的基台应力分析。

基本信息

批准号：
07672103
负责人：
ITOH Hidemi
金额：
$ 1.28万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

项目摘要

Prosthodontic cases involving periodontally compromised teeth will increase with a rapidly aging population. The need for an understanding of biomechanical considerations is especially great when designing treatment for periodontally compromised distal extension cases. An examination of load transfer characteristics of abutments and supporting structures in mandibular situations with a variety of periodontal defects was planned. The purpose of this study was to attain information vital to developing new guidelines for partial denture designs with an emphasis on preserving the abutment tceth as long as possible.In this study, 1) a new stress-analysis system was developed by adding to and improving on observation and recording techniques used in conventional Quasi-Three Dimensional Photoelastic methods of examining stress distribution characteristics in complex situations, and 2) photoclastic models were made to simulate various condition and stresses in the teeth and supporting structur … More es were analyzed. Specifically, models of i) unilateral distal extension cases (432 remaining) with various vertical and horizontal resorption (crater and trough defects for vertical resorption, and horizontal resorption rates of 20% and 35% were used), as well as ii) bilateral distal extension situations with vertical resorption in the first premolar abutment were fabricated. These models were tested against chromatic fringe patterns observed in models of a normal mandibular situation for their load transfer characteristics as load (quantity and direction), splinting, and retention device conditions were changed.The results showed that, 1) under the same load conditions, the highest stresses over the largest area developed in the model with the largest osseous defect, 2) stress distribution patterns were fundamentally different in models with vertical versus those with horizontal periodontal resorption, 3) two splints were most effective in redistributing loads incurred by periodontally compromised abutment teeth, and 4) the lbar clasp was the most effective in reducing the overall stress at the abutment tooth and producing an uniform stress redistribution. Less

随着人口的迅速老龄化，涉及牙周受损牙齿的修复病例将增加。在设计治疗牙周受损的远端延伸病例时，需要了解生物力学方面的考虑。本研究计划在有各种牙周缺损的下颌骨情况下，对基牙和支持结构的载荷传递特性进行检查。本研究的目的是获得重要的信息，以制定新的指导方针，局部义齿设计的重点是保持尽可能长的基牙tceth。在这项研究中，1）一个新的应力分析系统，通过增加和改进的观察和记录技术，在传统的准三维光弹性方法，检查应力分布特性在复杂的情况下，2）建立了光弹模型，模拟了牙齿和支持结构的各种状态和应力 ...更多信息 es进行了分析。具体而言，制作了i）单侧远端伸展病例（剩余432例）的模型，这些病例具有各种垂直和水平吸收（垂直吸收的环形和槽状缺损，水平吸收率为20%和35%），以及ii）第一前磨牙基台中具有垂直吸收的双侧远端伸展情况。这些模型进行了测试，对彩色条纹模式中观察到的一个正常的下颌骨的情况下，他们的负荷转移特性，作为负荷结果表明：（1）在相同载荷条件下，骨缺损最大的模型在最大面积上产生最大应力，2）牙周垂直吸收模型与牙周水平吸收模型的应力分布模式有根本性的不同，3）两种夹板在牙周受损基牙引起的载荷重新分配方面最有效，Lbar卡环在降低基牙总应力和产生均匀应力重分布方面效果最好。少