下颌第一磨牙全瓷冠参数化三维有限元模型的建立

Construction of three-dimensional finite parametic model of mandible first molar all-ceramic crown.

目的:探索建立下颌第一磨牙全瓷冠的三维有限元参数化模型。方法:选择1:15倍大小标准下颌第一磨牙模型,经3DSS-STDC-Ⅱ扫描仪扫描获得点云文件,Geomagic软件光滑处理,Unigraphics NX6软件生成模型,通过布尔运算等计算机辅助设计方法生成下颌第一磨牙参数化模型,并通过Office Excel 2007软件驱动参数生成后处理所需的模型。将所建的基本模型导入Ansys Workbench,经过自动网格划分并进行模拟准确性检测。结果:建立了包含饰瓷面厚度和基底面厚度参数的下颌第一磨牙全瓷冠的三维有限元参数化模型。基本模型包含147274个节点及100908个单元,应力分布结果显示,全瓷冠面加载点及颊侧面冠边缘出现应力集中区,等效应力峰值为24.055 Mpa。结论:通过合理的计算机辅助设计建立牙齿及修复体模型方法可行,为进行各类修复体的有限元系列研究提供快速、精确、简便的建模方法。

Objective：This study is aimed at developing a new method to facilitate the construction of 3D finite parametic model of mandibular first molar all-ceramic crown.Method：The three-dimensional finite element parametic model of mandibular first molar all-ceramic crown were constructed by means of 3DSS-STDC-Ⅱ scanning,digital image transfer,reverse engineering software Geomagic,computer aid design program unigraphics.The assembled models were input into Ansys Workbench software and be meshed and evaluated.Result：A parametic model including veneer occlusal thickness and core occlusal thickness were constructed.The basic model contains 147274 nodes and 100908 elements,and the stress concentrated on cervical of crown,the Maximum equivalent stress is 24.055 Mpa.Conclusion：The method enhances the accuracy,flexibility and efficiency in constructing a 3D finite element model with reverse enging and parameterization of Unigraphics,which provided the platform for the optimun design of all-ceramic crown.