不同洞型设计时基底材料和充填体对牙应力影响的三维有限元分析

Three dimensional finite element stress analysis on model of maxillary first premolar with different cavity designs and restorations

目的:分析不同洞型设计时基底材料和充填体对牙应力的影响。方法:建立上颌第一前磨牙面洞、邻面洞及邻邻面洞的三维有限元模型,采用四因素不同水平析因实验设计,在牙尖顶点、牙尖与充填体边缘连线的中点、充填体表面分别垂直加载100N的力,用ANSYS9.0有限元分析软件分析不同工况下面、颊侧颈部和远中边缘嵴牙体主应力的大小,采用SPSS13.0软件包对数据进行多变量方差分析。结果:受力部位、窝洞类型、充填体和基底材料种类对牙应力的影响有统计学意义,受力部位影响最大;基底材料仅对面应力有影响,牙颈部为高应力区。结论:面的受力部位是影响应力分布的最主要因素,充填体和窝洞类型也是影响应力的重要因素。

PURPOSE： To investigate the influence of stress on three-dimentional finite element models of maxillary first premolar with multifactors ：cavities designs,restored materials,basing materials and loading sites. METHODS： Three dimensional finite element models for maxillary first premolar with different types cavity which were filled with different basing materials and restoration were constructed and the maximum main stress was measured according to factorial design.ANSYSg.0 software were employed ,and the data was statistically analyzed with SPSS 13.0 software package for multivariate ANOVA. RESULTS： Loading sites,cavity designs,restored materials and basing materials had effects on stress. Loading sites were the most important factors. Basing materials only had effect on occlusal stress. Cervix region was one of the stress concentration sites. CONCLUSIONS： Loading site has significant influence on stress ,cavity designs, restored materials must be considered during restorations. Supported by Key Research Project of Science and Technology Commission of Liaoning Province （Grant No. 99225008）.