不同桩核材料对桩冠箍效应影响的三维有限元分析

[目的]研究桩冠修复中不同桩核材料对箍效应的应力分布影响,探讨箍效应的生物力学机制.[方法]建立正常上颌中切牙烤瓷核桩冠箍效应的三维有限元模型,模拟四种桩核材料(A组:铜合金,B组:金合金,C组:镍铬合金,D组:钛合金)的修复形式,通过静态加载分析牙本质受力情况.[结果]4种不同弹性模量的桩核材料,其Von Mises应力峰值在颈部分别为铜合金17.6 MPa,金合金17.6 MPa,镍铬合金23.8 MPa,钛合金17.6 MPa,镍铬合金组应力最高;在根部各组分别为26.8 MPa,22.9 MPa,39.3 MPa,26.9 MPa,金合金组应力最小,镍铬合金组最高,均有显著性差异(P<0.05).[结论]箍效应受桩核材料弹性模量的影响.高弹性模量的桩核材料,减弱了箍效应并使颈部及桩周牙本质应力过高.

Three-Dimensional Finite Element Analysis of Various Elastic Modulus of Post-Core on Ferrule Effect in Post Crown

[Objective]To investigate the effect of various post and core materials on stress distribution of ferrule effect in post crown, and to evaluate the biomechanics mechanism of ferrule effect in post crown. [Methods] A model of maxillary central incisor restored with post and porcelain-fused-to-metal (PFM) crown was built by three-dimensional finite element methods (3D-FEM). By imitating four post-core materials (Cu alloy, Au alloy, Ni-Cr alloy, Ti alloy), the dentin stress of ferrule effect under static loading was analyzed by 3D-FEM. [Results] When different post-core materials with various elastic moduli were used, the peak ferrule stress values in cervical and radical region were significantly different (P<0.05). The peak values of Von Mises stress in different models were:17.6 MPa for Cu alloy, 17.6 MPa for Au alloy, 23.8 MPa for Ni-Cr alloy (the highest), 17.6 MPa for Ti alloy in cervical region; 26.8 MPa for Cu alloy, 22.9 Mpa for Au alloy (the lowest), 39.3 MPa for Ni-Cr alloy (the highest), 26.9 MPa for Ti alloy in the root; respectively. [Conclusion]The ferrule effect is influenced by elastic modulus of post and core materials. The post with higher elastic modules weakens the ferrule effect virtually, and results in higher stress around post.