通过三维有限元法分析不同粘结层厚度对全瓷冠修复的影响,建立左下颌第一磨牙中央面洞充填的全瓷冠三维有限元模型,包含氧化锆全瓷冠、粘结层、洞形充填体、牙本质.粘结层采用Cement1、Cement2两种树脂材料,50 μm、100 μm、150 μm、200 μm四种厚度.分别模拟正常咬合、异常咬合两种咬合状态:载荷大小为200 N、700 N,垂直加载,加载点为5个.共建立16个三维有限元模型进行分析.两种咬合状态下各模型应力值分布规律相似,全瓷冠受力与粘结层材料几乎无关,粘结层受力随粘结层弹性模量增大而增大,最大主应力随粘结层厚度增大而减小,洞形充填体最大主应力随粘结层厚度增加缓慢升高;且高弹性模量粘结层受力低于低弹性模量粘结层受力.说明在对全瓷冠进行有限元分析时,应充分考虑粘结层的影响.推荐使用100~150 μm的粘结层厚度,可能有更好的临床效果.%In order to analyze the effect of all ceramic crown restoration with different cement thickness by three-dimensional finite element method,three-dimensional finite element models of a mandibular left first molar all ce-ramic crown restoration with central masticatory surface filling was established, including zirconia all ceramic crown,cement layer,cavity filling body and dentin. The cement layer was designed two kinds of resin materials, Cement1,Cement2,and 50 μm,100 μm,150 μm and 200 μm 4 kinds of thickness. Two occlusal states of nor-mal occlusion and abnormal occlusion were simulated respectively:vertical load of 200 N and 700 N at 5 points. 16 three-dimensional finite element models were established for analysis. The distributions of stress values of each model are similar under the two occlusal states, the stress of all ceramic crown are almost independent of cement material,the stress of the cement layer increases with the increase of the elastic modulus of the cement layer,and the maximum principal stress decreases with the increase of the thickness of the cement layer,the maximum princi-pal stress of the cavity filling body increases slowly with the increase of the cement layer thickness,and the stress of the cement layer with high elastic modulus is lower than the low elastic modulus. In the finite element analysis of all ceramic crown,the influence of the cement layer should be taken into consideration,and cement layer thickness of 100~150 μm is recommended that may be have better clinical results.
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