不同边缘设计的聚合瓷高嵌体修复后牙体组织的有限元应力分析  

Finite element stress analysis on the tooth tissue repaired with polymerized porcelain onlay with different designs of marginal preparation

作　　者：缪羽[1] 吴凯敏[1] 于蕴之[1] 李利[1] 

机构地区：[1]内蒙古医学院第四附属医院口腔科,014030

出　　处：《现代口腔医学杂志》2011年第6期440-445,共6页Journal of Modern Stomatology

摘　　要：目的建立不同边缘设计的下颌第一恒磨牙高嵌体修复后的三维有限元模型,分析修复体和牙体组织的应力变化。方法通过口腔科专用的锥形束CT扫描离体下颌第一恒磨牙,建立牙齿的三维图像,利用Solidwoks2010软件和有限元分析软件Ansys12.0建模并进行受力分析;得到等效(Von Mises)应力云图。根据应力云图,分析90°肩台、135°肩台、内线角圆钝的直角肩台三种不同边缘设计的聚合瓷高嵌体修复后修复体和牙体组织的应力分布情况。结果①三种肩台设计聚合瓷高嵌体修复后,无论是垂直向还是斜向加载,等效应力主要集中在加载部位和牙根侧壁,牙颈部应力均明显减轻。②无论是施加150N还是300N载荷,垂直加载时,90°肩台和135°肩台设计时,在牙合面窝洞轴髓线角处均有应力集中区,而内线角圆钝的直角肩台设计在此处应力分布均匀;斜向加载时,牙合面洞型侧壁等效应力峰值比较均是:90°肩台设计>135°肩台设计>内线角圆钝的直角肩台设计。结论①采用三种边缘设计的复合树脂高嵌体修复时,都明显减轻了牙颈部的应力分布。②在覆盖牙尖的树脂高嵌体修复时,边缘设计最好采用内线角圆钝的直角肩台设计。Objective To observe the stress changes of dummy and tooth tissue after establishing the 3D finite element models of mandibular first molar restored by applying onlays with different margin designs.Methods The dental CT image was obtained by scanning the mandibular first molar with CBCT.The integral stress cloud diagram was gained by utilizing Solidwoks2010 and Ansys10.0.Based on the cloud diagram,the stress distribution was analyzed of the onlay with different marginal designs of 90°shoulder,135°shoulder,and right angle shoulder.Results ① No matter loaded vertically or slantly,equivalent stress mainly focused on the loaded part and the side of the tooth root,while the stress on the tooth neck was obviously reduced.② When loaded vertically,no matter with 150N or 300N,the stress-focused area always appeared in the axiopulpal line angel of the occlusal cavity both in 90°shoulder and 135°shoulder designs;on the contrary,it was uniformly distributed in 90°shoulder design with round and obtuse inner line angel.When loaded slantly,the comparison of the maximum value of stress in the occlusal cavity lateral wall was： 90°shoulder design135°shoulder design90°shoulder design with round and obtuse inner line angel.Conclusion ①The stress distribution of the teeth neck is significantly reduced by using three marginal design of composite resin onlay restoration.②We＇d better adopt insider angle obtuse orthogonal shoulder platform design,when the composite resin onlay will be covered.

关 键 词：下颌第一恒磨牙 聚合瓷 高嵌体 有限元应力分析 肩台 

分 类 号：R783.2[医药卫生—口腔医学]