Fennis W M M, Kuijs R H, Barink M, Kreulen C M, Verdonschot N, Creugers N H J
Department of Oral Function and Prosthetic Dentistry, College of Dental Science, Radboud University Nijmegen Medical Center, Nijmegen, the Netherlands.
Eur J Oral Sci. 2005 Oct;113(5):443-8. doi: 10.1111/j.1600-0722.2005.00233.x.
The aim of this study was to explore and compare the results of occlusal load application to cusp-replacing composite restorations, studied by means of finite element (FE) analysis and in vitro load tests. A three-dimensional (3D) FE model was created with a set up similar to an in vitro load test that assessed the fatigue resistance of upper premolars with buccal cusp-replacing resin composite restorations. Occlusal load was applied to two geometries (with and without palatal cuspal coverage), and the tooth-restoration interface and composite material stresses were calculated. Subsequently, safety factors were calculated by dividing the material strength values by the obtained stresses. The highest safety factors were observed for the restorations with cuspal coverage. This was consistent with the load test, in which cuspal coverage led to higher fracture resistance. Furthermore, the FE analysis predicted that failure of the tooth-restoration interface is more likely than failure of the composite material. Correspondingly, the load test showed predominantly adhesive failures of the restorations. Although the described test methods did not lead to a complete understanding of the failure mechanism, it can be concluded that the FE analysis provides additional information with regard to the differences in fracture behaviour of these types of restorations.
本研究的目的是通过有限元（FE）分析和体外载荷试验，探索并比较对尖牙替代复合树脂修复体施加咬合载荷的结果。建立了一个三维（3D）有限元模型，其设置类似于体外载荷试验，该试验评估了带有颊尖替代树脂复合树脂修复体的上颌前磨牙的抗疲劳性。对两种几何形状（有和没有腭尖覆盖）施加咬合载荷，并计算牙齿-修复体界面和复合材料应力。随后，通过将材料强度值除以获得的应力来计算安全系数。观察到有尖覆盖的修复体安全系数最高。这与载荷试验结果一致，在载荷试验中，尖覆盖导致更高的抗折性。此外，有限元分析预测牙齿-修复体界面的失效比复合材料的失效更有可能发生。相应地，载荷试验显示修复体主要发生粘结性失效。尽管所描述的试验方法未能完全了解失效机制，但可以得出结论，有限元分析提供了关于这些类型修复体断裂行为差异的额外信息。
