不同厚度饰瓷与基底瓷双层结构全瓷桥残余应力的有限元分析  

The finite element analysis of the residual stress in the veneer and core porcelain with different thickness for the bilayered all-ceramic bridge

作　　者：丁洁[1] 王伟峰[1] 辛海涛[1] 赵燕芳[1] 欧阳炎[2] 

机构地区：[1]第四军医大学口腔医学院修复学教研室,陕西西安710032 [2]西北工业大学航空学院结构工程系,陕西西安710072

出　　处：《临床口腔医学杂志》2012年第6期333-336,共4页Journal of Clinical Stomatology

基　　金：陕西省科技攻关项目资助(2008K01-42)

摘　　要：目的:建立不同厚度饰瓷与基底瓷双层结构的后牙三单位全瓷桥有限元模型,分析饰瓷与基底瓷厚度对全瓷桥残余应力的分布及其影响。方法:使用WIELAND ZENOTEC Scan对上颌后牙三单位固定桥基牙标准模型进行三维光学扫描,在上述模型基础上通过WIELAND ZENOTEC Cad;Geomagic;CATIA构建三组不同厚度饰瓷与基底瓷双层结构后牙三单位全瓷桥实体模型,将模型导入ABAQUS6.10有限元软件,分析修复体从575℃降至室温25℃过程中残余应力的形成及分布。结果:全瓷修复体残余应力主要分布在饰瓷与基底瓷结合界面处,其中冠边缘、连接体处修饰瓷分布较薄的部位界面处残余应力较为集中,而在修饰瓷较厚的部位残余应力分布较为均匀。随着温度的降低,饰瓷与基底瓷结合界面的残余应力逐渐增大。随着饰瓷与基底瓷热膨胀系数之差逐渐增大和饰瓷厚度的增加,结合界面的残余应力也逐渐增大。结论:双层结构全瓷桥三维有限元模型的建立使得修复体残余应力分析得以实现。修饰瓷较薄和热膨胀系数差较大时残余应力分布较大,在进行全瓷桥修复时除饰瓷与基底瓷热膨胀系数匹配外,要保证饰瓷一定的厚度。Objective： To investigate the effect of different thicknesses of veneer and core porcelain on the residual stress distribution on the 3D finite element model of the bilayered all-ceramic bridge. Method.. The 3D surface picture of the maxillary tooth and three units fixed bridge were obtained through WIELAND ZENOTEC Scan, WIELAND ZENOTEC Cad, Geomagic, and CATIA were employed to transform the surface picture of the teeth, veneer and core of the bilayered all-ce- ramic bridage in different thickness into the 3D solid models, in order to build the 3D finite element model of three units fixed bridge. The residual stress of the models were analyzed when the temperature of the model was decreased from 575 ℃ to 25 ℃. Result： The residual stress of the all-ceramic bridage was distributed mainly on the interface between the core and veneer on the margin. The concentration of the residual stress was at the margins areas of the crown and the connector with thinner veneer porcelain, while it was uniform at the thicker veneer porcelain regions. The residual stress was increased with the decreasing of the temperature, and it was also increased gradually with the increasing of the difference of thermal expansion coefficient between core and veneer porcelain and veneer porcelain thickness. Conclusion： The residual stress analysis can be achieved through the analysis to the three-dimensional finite element model of the bilayrerd all-ceramic bridge established. The residual stress appears higher in the place where veneer porcelain is thinner and when the difference of thermal expansion coefficient is obvious. These results suggest that the compatibility of thermal expansion of core and veneer porcelain should be taken into account, and the thickness of veneer ceramic should also be considered in all-ceramic bridage design, suggesting.

关 键 词：全瓷桥 氧化锆 有限元分析 残余应力 

分 类 号：R783.3[医药卫生—口腔医学]