上颌第一恒磨牙不同桩核形式对牙本质应力影响的三维有限元分析

目的用三维有限元方法分析上颌第一恒磨牙2种不同形式桩核对牙本质应力的影响。方法利用多层螺旋CT扫描获得上颌第一恒磨牙的原始数据,采用多种软件相结合的方法,建立上颌第一恒磨牙及桩核的三维实体和三维有限元模型。在ANSYS10.0中分别作颊向(与牙长轴45°)、垂直、腭向(与牙长轴45°)加载,作用力100N,得到牙本质内部Von Mises应力云图及峰值应力数据。结果不同形式桩核及不同加载方向对牙本质应力分布有不同的影响。结论不平行桩核更有利于保护剩余的牙根组织。

Three-dimensional finite element stress analysis of two forms of post-core restoration of maxillary first molar

Objective To study the stress distribution discipline of root of the maxillary first molar restored by two forms of post-core(Group A:unparallel post;Group B: parallel post). Methods With the data from the multi-slice CT scanning image of a maxillary first molar, we used softwares to reconstruct a three-dimensional finite element model of maxillary first molars and two forms of post-core. A 100 Newton force,simulating masticatory force,was applied from three directions:①At a vertical load on the occlusion surface;② at an angle of 45 degrees to the longitudinal axis from buccal side;③at an angle of 45 degrees to the longitudinal axis from lingual side. We investigated the stress distributions of root of the maxillary first molar restored by two forms of post-core. Results The differences of the post-core and loading lead to the various stress distributions. Conclusion The stress distribution of group A is better than that of group B.