Department of Dental Materials and Biomaterials Research, RWTH Aachen University Hospital, Pauwelsstrasse 30, 52074 Aachen, Germany.
Dent Mater. 2011 Aug;27(8):e171-5. doi: 10.1016/j.dental.2011.04.009. Epub 2011 May 17.
Finite element analysis is a standard method to simulate the stress distribution in all-ceramic dental restorations in order to estimate the loading capacity of the brittle components. The hypothesis of this study was that stresses in the connector area of a veneered FDP are strongly influenced by the framework dimensions and the veneering material.
Finite element analyzes of bilayered fixed dental prostheses with three different framework-designs and three different veneering materials were conducted, applying the loads onto the veneering as well as directly onto the framework. The outer shape of the veneering ceramic remained constant for all cases.
The maximum first principal stresses in the framework of the fixed dental prostheses (FDP) decreased with smaller framework dimensions when the load was applied on the veneering. By applying the load directly onto the framework of the FDP without veneering a converse tendency was found. The variation of the veneering material lead to the conclusion that stresses in the framework became higher with decreasing Young's modulus of the veneer, while the stresses in the veneer increased at the same time.
The veneering material plays a significant role for the failure of a FDP and cannot be neglected neither in testing nor in simulation. Thus the loading capacity of dental restorations can only be reasonably evaluated when the whole restoration is taken into account, including framework and veneering.
有限元分析是一种模拟全瓷牙科修复体中应力分布的标准方法，以便估计脆性部件的承载能力。本研究的假设是，贴面 FDP 连接区域的应力强烈受到框架尺寸和贴面材料的影响。
对具有三种不同框架设计和三种不同贴面材料的双层固定义齿进行了有限元分析，将负载施加到贴面以及直接施加到框架上。所有情况下，贴面陶瓷的外形成都保持不变。
当负载施加到贴面时，固定义齿（FDP）框架中的最大第一主应力随框架尺寸的减小而减小。当不贴面直接将负载施加到 FDP 的框架上时，发现了相反的趋势。贴面材料的变化得出结论，随着贴面杨氏模量的降低，框架中的应力会升高，同时贴面中的应力也会增加。
贴面材料对 FDP 的失效起着重要作用，在测试和模拟中都不能忽视。因此，只有考虑整个修复体，包括框架和贴面，才能合理评估牙科修复体的承载能力。
