基底冠结构变化对金属烤瓷冠应力分布影响的三维有限元分析

目的探讨基底冠结构变化对后牙金属烤瓷冠应力分布的影响,为基底冠的结构设计提供理论指导。方法将金属基底冠设计为均匀厚度形、蝶形和水平形三种结构型,建立金属烤瓷冠三维有限元模型,模拟加载1N垂直载荷时的应力分布。结果瓷层最大主应力主要集中于金瓷界面,蝶形结构型和水平结构型的瓷层最大主应力峰值明显低于均匀厚度型,而最小主应力峰值则明显高于均匀厚度型。蝶形结构型和水平结构型的基底冠von-Mises应力峰值明显低于均匀厚度型。结论蝶形结构型和水平结构型基底冠设计,能有效优化金属烤瓷冠的应力分布,提高瓷层的抗拉强度,增强金属烤瓷冠的结构强度。

Effect of stress distribution of different metal framework on metal-ceramic crown by three-dimensional finite element analysis

Objective To investigate the influences of different metal framework on the stress distribution of posterior ceramic - metal crown, and to provide theoretical guidance for designing metal framework. Methods Three kinds of metal framework were designed as traditional framework, butterfly framework and flat framework. Three - dimensional finite element models were created and the stress distribution was simulated respeetively. Loading direction was vertically downward along tooth axis with a load of 1 N. Results The maximum principal stress in porcelain occurred at the porcelain - metal interface. The peak of the maximum principal stress in porcelain for traditional framework was much higher than that of butterfly framework and flat framework, but the peak of the minimum principal stress was obviously lower than that of hutterfly framework and flat framework. The peak of van - Mises was also markedly higher than that of butterfly framework and flat framework. Conclusion The butterfly and flat frame designs can effectively change the stress distribution of ceramic - metal crown, optimizing stress distribution in porcelain under perpendicular load, and enhance structural strength of porcelain.