Ceramic Prosthesis Survival Based on Cares/Life Analysis

描述：本研究的总体目标是研究双层和三层牙科陶瓷结构的时间依赖性可靠性。将有限元分析（目标1）计算的应力输入到目标3和目标4中使用的新版本6.1 NASA CARES/Life软件（结构/寿命的陶瓷分析和可靠性评估）中，将产生金属/陶瓷和陶瓷/陶瓷结构的生存概率，作为热收缩不匹配、几何形状、表面处理和热处理效果的函数。具体目标2侧重于三种热处理对残余应力的影响，以及循环载荷对热相容和热不相容双层陶瓷基结构抗弯强度的影响。将研究陶瓷/陶瓷层压板界面区域和表面的热失配应力与基于膨胀测量和粘度数据的有限元分析预测的应力之间的相关性。我们将优化热处理方案，以提高已知热不相容的核心陶瓷/贴面陶瓷系统的残余应力分布。根据目标1和目标2的数据，将在目标3中进行CARES/Life分析，以确定由热相容和热不相容的核心陶瓷/贴面陶瓷系统制成的陶瓷棒和桥的延迟失效可靠性。界面缺陷（Aim 4）对随时间变化的可靠性的影响也将被分析，用于具有玻璃贴面的二硅酸锂基玻璃陶瓷芯，该玻璃贴面在临床表现出贴面剥落，以及已知易受界面分层影响的氧化钇稳定的氧化锆芯/贴面系统。Aim 4还将分析两种缺陷陶瓷/陶瓷结构的界面韧性和界面断裂特征，以及基于CARES-Life分析的两种双层结构的时间相关强度。这项研究将产生临床相关的疲劳数据和一种改进的方法来评估陶瓷假体的时间依赖性生存概率。

DESCRIPTION: The overall goal of this study is to investigate time-dependent reliability of bilayer and tri-layer Dental ceramic structures. Input of stresses computed from finite element analysis (Aim 1) into the new Version 6.1 NASA CARES/Life software (Ceramic Analysis and Reliability Evaluation of Structures/Life) used in Aims 3 and 4 will yield survival probabilities of metal/ceramic and ceramic/ceramic structures as a function of thermal contraction mismatch, geometry, surface treatment, and heat treatment effects. Specific Aim 2 is focused on the effect of three thermal treatments on residual stresses and the impact of cyclic loading on the flexural strength of thermally compatible and thermally incompatible bilayer ceramic-based structures. Correlations will be investigated between thermal mismatch stresses within the interfacial region and surface of ceramic/ceramic laminates computed from microhardness indentation cracks and stresses predicted from finite element analysis based on dilatometry and viscosity data. We will optimize heat treatment options to enhance the residual stress distribution for a known thermally incompatible core ceramic/veneer ceramic system. CARES/Life analyses will be performed in Aim 3 based on data from Aims 1 and 2 to determine the delayed failure reliability of ceramic bars and bridges made from a thermally compatible and thermally incompatible core ceramic/veneer ceramic system. The influence of interfacial defects (Aim 4) on time-dependent reliability will also be analyzed for a lithia-disilicate-based glass-ceramic core with a glass veneer that has exhibited veneer spallation clinically and an yttria-stabilized zirconia core/veneer system known to be susceptible to interfacial delamination. Aim 4 will also analyze the interfacial toughness and interfacial fracture characteristics of two defective ceramic/ceramic structures and the time-dependent strength of the two bilayer structures based on CARES-Life analysis. This study should yield clinically-relevant fatigue data and an improved method for assessing the time-dependent survival probability of ceramic prostheses.