不同厚度上颌中切牙全瓷冠应力分布的有限元研究

摘要

Objective To investigate the stress distributions under load in an all-ceramic crown of the upper central incisor in differential thickness. Methods The 3-dimensional finite element model of all-ceramic crown of the upper central incisor in differential thickness was applied with differential loads(100, 150, 200 N). The stress values and distributions of all-ceramic crown were calculated and expressed. Results The tendency of stress distributions in all-ceramic crown of differential thickness and loads was similar. The maximal stress intensity value was located in the loading site and the cervical region. As the thickness of all-ceramic crown increased, the stress concentration reduced. When the load increased, the stress values increased, especially in the loading site and the cervical region. Conclusion The increasing of the thickness of all-ceramic crown will decrease stress concentration. Because stress concentration is mainly in cervical region and loading site, these regions should be cared in fabrication of all-ceramic crown.%目的 研究不同厚度上颌中切牙全瓷冠受载时的应力分布特点.方法 利用上颌中切牙全瓷冠的三维有限元模型,对3种不同厚度的全瓷冠分别进行100、150、200 N载荷模拟加载,并进行力学分析.结果 不同厚度全瓷冠不同载荷下的应力分布趋势相似,应力集中于冠的颈缘及加载点.随着厚度增加,应力集中趋势明显减弱.随着载荷增加,各部位的等效应力相应增加,加载点及颈缘尤为明显.结论 全瓷冠厚度的增加可降低应力集中.颈缘和加载点为应力集中区,全冠制作时应注意加强该区域.