过渡层弹性模量对全瓷叠层冠应力分布影响的实验研究

目的 分析过渡层弹性模量对全瓷叠层冠应力分布的影响。方法 在上颌第一磨牙叠层冠有限元模型上,对照组过渡层弹性模量与饰面瓷同为70 GPa,实验组过渡层厚度为0.6 mm,弹性模量分别为175、150、100 Gpa,进行力的加载,对模型饰瓷表面最大主应力进行计算,导出最大主应力云图及各应力集中区最大主应力值。结果 实验组随过渡层弹性模量增加,所有最大主应力集中区的高应力区面积逐渐减小,饰面瓷加载区最大主应力值无明显变化,但次主应力集中区的最大主应力值下降,并且随着弹性模量的增加,下降幅度增加。结论 设计过渡层有利于分散全瓷叠层冠饰面瓷应力,并且其弹性模量越大分散效果越好。

Effects of interfacial transition zone(itz) on stress distribution of dental all-ceramic layered crown: a finite element model study

Objective To study the effects of elasticity modulus of interfacial transition zone(ITZ) on stress distribution on a constructed three-dimensional finite element model of all-ceramic layered structure of the first maxillary molar.Methods For the control model, elasticity modulus of ITZ and veneer layer was 70 GPa, and elasticity modulus of test model was 175 GPa, 150 GPa and 100 GPa, respectively, with the same thickness of 0.6 mm. Loads of 200 N were applied, then maximum principal stress was calculated.Results In all test groups,high stresses developed in the surface of the veneer were not affected, but the maximum principal stress''(MPS) value and extent of the sub-MPS areas decreased while elasticity modulus increased.Conclusion ITZ zone can disperse stress concentration of all-ceramic layered crown, and the effects is positively associated with higher modulus.