纤维桩核冠修复下颌第一磨牙的三维有限元分析

Three-dimensional Finite Element Analysis of the First Mandible Molar Restored with Fiber Post-core Crowns

目的:建立纤维桩核冠修复下颌第一磨牙的三维有限元模型,并分析其在面载荷工况条件下的应力情况。方法:选取标准离体下颌第一磨牙,建立纤维桩树脂核烤瓷冠修复下颌第一磨牙的三维有限元模型;修改材料属性模拟不同牙体缺损状况、桩核设计,施加4种面载荷工况,分析瓷层、冠粘接剂、牙本质的Von Mises stress应力情况。结果:建立的三维有限元模型与纤维桩核冠修复下颌第一磨牙的临床实际情况有良好相似性。不同载荷工况,应力分布云图差异明显;载荷工况相同,应力分布云图差异不明显。近中功能接触(load 10),应力极值均较大;核弹性模量增大,瓷层应力极值增大,冠粘接剂、牙本质应力极值减小;桩弹性模量增大,瓷层、冠粘接剂应力极值增大。结论:载荷工况对修复效果的影响大;高弹性模量的树脂核及低弹性模量的纤维桩有利于保护牙体及维持冠粘接效果。

Objective:To establish three-dimensional finite element models for the first mandible molar restored with fiber post core crowns,and analyze their stress under the different condition of face loads.Methods:The standard first mandible molar was selected to Establish the three-dimensional finite element models.The material properties were modified to simulate different tooth defects and post-core designs.4 kinds of loads were applied on the crowns,and the Von Mises stress of porcelain,crown adhesive and dentin were analyzed.Results:The three-dimensional finite element models were similar to the clinical situations of the first mandibular molar restored with fiber post-core crowns.Under different loads,the stress distributions were obviously different.With the same loads,the stress distributions were almost similar.Under mesial functional contact(load 10),the stress extremes were larger than the other.With the increase of the elastic modulus of the core material,the maximum stress of the ceramic increased,but crown adhesive and dentin decreased.With the increase of elastic modulus of post material,the maximum stress of porcelain and crown adhesive increased.Conclusion:The results suggested that loading conditions had great influence on the restoration effect,and resin core materials with high modulus of elasticity and fiber post materials with low modulus of elasticity were conducive to the protection of teeth and the maintenance of crown bonding.