SD附着体固位远中游离端可摘局部义齿三维有限元应力分析

目的：对比分析刚性及弹性附着体义齿的应力分布，为临床选用附着体提供理论参考。方法：建立下颌第二磨牙游离缺失的附着体义齿三维模型。采用有限元应力分析方法，分析2种附着体义齿基牙应力分布情况。结果：（1）在垂直载荷下，2种附着体基牙在牙槽嵴顶处均有应力集中。弹性附着体基牙牙根主应力下降26％-58％；剩余牙槽嵴应力峰值减小50％。（2）斜向载荷时，应力集中更明显，弹性附着体应力峰值仍有一定减小。结论：弹性附着体固位的可摘局部义齿，更有利于保护基牙及支持组织，保护剩余牙槽嵴。

Three-dimensional finite element analysis of SD attachment retained distal-extension removable partial denture

Objective: To compare and analyze the stress level of rigid and resilient attachment-retained distal extension RPD. Provide a guide in selecting attachment properly in practice. Methods: The three-dimensional finite element method was used to investigate the stress distribution of the abutment and its support tissue with rigid /resilient attachment retained distal-extension removable partial denture under 100N vertical and lingual laod. Two idealized 3-dimensional finite element computer models were built, which consisted of a mandibular posterior segment and a RPD retained by attachment. Results: 1.Under vertical load, the most extreme stress values were located at the alveolar ridge crest distal/mesial to the abutment of two type of attachment. The principal stress of the abutment with resilient attachment was significantly decreased from 26% to 58%and well- distributed, the stress value of residual ridge was reduced by 50%. 2. Under the oblique load, the maximal stress was much higher than that under vertical load. The maximum stresse of resilient attachment was still decreased. Conclusions: Resilient attachment was more favorable than the rigid one to protect the abutment and its support tissue, and to preserve the residual ridge.