Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand.
J Endod. 2010 Jan;36(1):115-8. doi: 10.1016/j.joen.2009.09.026.
The aim of this study was to investigate and compare stress distribution in various degrees of curved roots with different post and restorations by finite element analysis (FEA).
Sixteen 3-dimensional FEA models were created and adapted by using computer software based on external anatomy of mandibular second premolar. A 50-N load was applied. Tensile and compressive stresses were plotted.
The stress distribution pattern showed that degrees of root curvature in this study (15, 30, and 45 degrees) had little effect. When the elastic modulus of post and core materials was similar to that of root dentin, tensile stresses were low and concentrated on the external root surface. With higher elastic modulus of materials, tensile stresses were increased and concentrated on the post and post apex.
Within the limitations of this study, the suitable restoration in endodontically treated mandibular premolar with limited loss of tooth structure was resin composite that was filled in the coronal third of the root canal. However, when the post and core were indicated, the glass-fiber post and resin composite core were the materials of choice for restoration.
本研究旨在通过有限元分析（FEA）研究和比较不同程度弯曲根管在不同桩核修复后的应力分布。
使用计算机软件基于下颌第二前磨牙的外部解剖结构创建并适应了 16 个 3 维 FEA 模型。施加 50-N 的载荷。绘制拉伸和压缩应力。
应力分布模式表明，本研究中的根弯曲程度（15、30 和 45 度）影响不大。当桩核材料的弹性模量与根管牙本质相似时，拉伸应力较低且集中在外部根管表面。随着材料弹性模量的增加，拉伸应力增加并集中在桩和桩尖上。
在本研究的限制范围内，对于牙体组织有限损失的根管治疗后的下颌前磨牙，合适的修复是填充在根管冠三分之一的树脂复合材料。但是，当需要桩核时，玻璃纤维桩和树脂核复合材料是修复的首选材料。
