开髓洞型对全冠修复后隐裂牙抗力影响的三维有限元研究

目的探讨在牙隐裂患牙根管治疗中采用传统开髓洞型和微创开髓洞型对烤瓷全冠修复后牙体抗力的影响。方法制作3种裂纹深度的牙隐裂三维虚拟模型,模拟微创开髓和传统开髓,并完成根管治疗和烤瓷全冠修复。在垂直加载和斜向加载条件下,记录牙体应力的分布情况和数值大小。结果在2种加载条件下,修复前牙齿应力集中于裂纹底部,局部应力集中随着隐裂深度的加深而增大,烤瓷全冠修复后基牙局部应力主要分布在肩台处,局部应力集中得到大幅缓解。不同开髓洞型对隐裂牙应力分布和大小的影响无明显差异。结论根管治疗后烤瓷全冠修复是治疗牙隐裂的有效措施;相比传统开髓洞型,微创开髓洞型并不能改善全冠修复后隐裂牙的应力分布。

Three-dimensional finite element study on the effect of pulp opening cavity on the resistance of cracked teeth after full crown restoration

Objective To investigate the effect of traditional endodontic cavity and minimally invasive endodontics root canal therapy on the resistance of teeth restored with porcelain crowns.Methods Three dimensional virtual models of cracked teeth with three different depth of crack were made to simulate minimally invasive endodontics and traditional endodontic cavity,and complete root canal therapy and porcelain crown restoration.Under the condition of vertical loading and oblique loading,the distribution and numerical value of tooth stress were recorded.Results Under the two loading conditions,the stress of the teeth before the treatment was concentrated at the bottom of the crack,and the local stress concentration increased with the deepening of the depth of the crack.The local stress of the abutment was mainly distributed at the shoulder after the restoration of the porcelain full crown.The local stress concentration has been greatly alleviated.There was no significant difference in the effect of different endodontic cavity on the stress distribution and magnitude of cracked teeth.Conclusion The restoration of porcelain crowns after root canal therapy is an effective measure for the treatment of cracked teeth.Compared with the traditional endodontic cavity,the minimally invasive endodontics cannot improve the stress distribution of cracked teeth after full crown restoration.