Faculty of Dentistry, Department of Endodontics, University of Selcuk, Konya, Turkey.
Clin Oral Investig. 2011 Jun;15(3):403-8. doi: 10.1007/s00784-010-0397-7. Epub 2010 Mar 18.
The aim of this finite element method (FEM) study was to test two different restorative techniques used for construction of severely damaged endodontically treated premolar teeth using Finite Element Stress Analysis Method. In this study, four types of three-dimensional (3-D) FEM mathematical models simulating (1) a sound lower single rooted premolar tooth with supporting structures; (2) a root-filled lower premolar tooth without lingual cusp, restored with resin composite; (3) a root-filled lower premolar tooth without lingual cusp restored with resin composite in combination with a polyethylene fiber which is placed circumferentially to help to create a composite lingual wall; (4) a root-filled lower premolar tooth without lingual cusp restored with resin composite in combination with a glass fiber post, were modeled. A 300-N static vertical occlusal load was applied on the node at the center of occlusal surface of the tooth to calculate stress distributions. Solidworks/Cosmosworks structural analysis programs were used for FEM analysis. The analysis of the von Mises stress values revealed that maximum stress concentrations were located at loading areas for all models. Root dentine tissue, lingual cortical bone, and apical bone structures were other stress concentration regions. There were stress concentration differences among the models at root dentine tissue. Although the distribution pattern was similar with composite resin restored tooth model, highest stress values were observed at root dentine in the model restored with post-and-core. Post structure accumulated more stress on its own body. Stress distribution patterns of sound tooth and fiber-reinforced restoration models were found as similar. The present study showed that the use of post material increased the stress values at root dentine structure while reinforcing the restoration with a fiber decreases stress transmission. Fiber-reinforced restoration provided stress distributions similar to sound tooth.
本有限元法（FEM）研究旨在通过有限元应力分析方法测试两种不同的修复技术，用于构建严重受损的根管治疗前磨牙。在这项研究中，模拟了四种三维（3-D）FEM 数学模型：（1）具有支持结构的健康下单个根前磨牙；（2）无舌尖的根管填充下前磨牙，用树脂复合材料修复；（3）无舌尖的根管填充下前磨牙，用树脂复合材料结合环形放置的聚乙烯纤维修复，以帮助形成复合舌侧壁；（4）无舌尖的根管填充下前磨牙，用树脂复合材料结合玻璃纤维桩修复。在牙齿咬合面中心的节点上施加 300-N 的静态垂直咬合载荷，以计算应力分布。使用 Solidworks/Cosmosworks 结构分析程序进行 FEM 分析。对 von Mises 应力值的分析表明，所有模型的加载区域都存在最大的应力集中。根牙本质组织、舌侧皮质骨和根尖骨结构是其他的应力集中区域。在根牙本质组织中，各模型之间存在应力集中差异。尽管与复合树脂修复牙模型的分布模式相似，但在桩核修复模型中，根牙本质的应力值最高。桩结构自身会积累更多的应力。健康牙模型和纤维增强修复模型的应力分布模式相似。本研究表明，使用桩材料会增加根牙本质结构的应力值，而用纤维增强修复会减少应力传递。纤维增强修复提供了类似于健康牙的应力分布。
