不同牙尖斜度带桩嵌体修复下后牙短冠的有限元应力分析

Finite element analysis on the stress in mandibular first molar short crown restored by post inlay of different cuspal inclination

背景:目前临床着重于研究带桩嵌体的材料和桩长度,而对其面形态的研究较少。目的:采用三维有限元方法,分析不同牙尖斜度的带桩嵌体对下颌第一磨牙残冠修复牙本质应力大小和分布的影响,探讨带桩嵌体修复下颌第一磨牙短冠的面形态设计。方法:采用CT扫描,Mimics软件及Unigraphics NX6.0建立右下颌第一磨牙带桩嵌体的三维有限元模型,包括带桩嵌体,牙冠,牙根,牙周膜,牙槽骨。在不同模型的咬合接触区,施加240N的加载力值,分析不同牙尖斜度的带桩嵌体对牙残冠修复牙本质的最大主应力,Von-mises应力峰值和分布情况。结果与结论:随牙尖斜度的增加,牙本质的各项应力峰值和应力分布范围逐渐增大。说明不同牙尖斜度的带桩嵌体对后牙残冠修复牙本质应力值和分布有较大影响。

BACKGROUND：Clinical research about the post inlay mainly focuses on inlay materials and pile length,while the research on the morphology of the occlusal surface is rare.OBJECTIVE：To analyze the stress magnitude and distribution of remaining dentin and parodontium in mandibular first molar short crown restored with post inlay using three-dimensional finite element method.And then to discuss the rational core design of occlusal surface of mandibular first molar short crown.METHODS：The three-dimensional element models of mandibular first molar short crown restored with post inlay were created by CT scanning,Mimics software and Unigraphics NX6.0 software.Different cuspal inclination of post was used in the modeling,including post inlay,crown,root,periodontal ligament and alveolar bone.A load of 240 N was applied to the occlusal surface in order to analyze the maximum principal stress,Von-mises peak stress and distribution of remaining dentin in mandibular first molar short crown restored with post inlay.RESULTS AND CONCLUSION：The maximum stress on remaining dentin and parodontium increased markedly with the increasing of different cuspal inclination.Cuspal inclination has influence on magnitude and distribution of stress on remaining dentin and parodontium in mandibular first molar short crown restored with post inlay.