不同长度铸造分体桩核修复重度缺损上颌磨牙三维有限元分析

Three-dimensional finite element analysis of severely damaged maxillary first molar restored with cast post and cores of different length

目的通过三维有限元法分析不同长度铸造分体桩核修复重度缺损上颌第一磨牙后牙体组织应力分布。方法以右上颌第一磨牙为标本,通过CT扫描获得图像信息,采用Mimics三维建模软件、FreeForm视觉设计系统,建立五种不同长度铸造分体桩修复重度缺损上颌第一磨牙的三维有限元模型,利用Ansys有限元软件比较加载后牙体组织的Von Mises应力、最大拉应力分布和变化。结果随着铸造分体桩中颊根桩长度增加,上颌磨牙牙体组织Von Mises应力峰值减小,但拉应力峰值却增大;随着铸造分体桩中腭根桩长度增加,上颌磨牙牙体组织Von Mises应力峰值和拉应力峰值均减小。结论铸造分体桩修复重度缺损上颌第一磨牙时,根桩长度影响牙体组织应力分布。

Objective The study was designed to analyze the stress of severely damaged maxillary first molar restored with cast post and cores of different length. Methods A normal human right maxillary first molar was used to build some three - dimensional finite element models of severely damaged maxillary first molar restored with cast post of different length and cores. Three-dimensional finite element models were created with softwares of Mimics, Freeform and Ansys. Three-dimensional finite element analysis was performed on the models under static loads and the distribution and changes of Von Mises stress and maximal tensil stress in the dentine were compared among different models. Results The maximal ~on Mises stress on dentine decreased when the length of buceal posts increased,but the maximal tensil stress on dentine increased when the length of buccal posts increased. The maximal Von Mises stress and the maximal tensil stress decreased when the length of palatal posts increased. Conclusions The length of posts could influence the stress distribution in the dentine of severely damaged maxillary first molar restored with cast posts and cores.