Interfacial Fatigue Damage in Onlay Ceramic Restorations

描述：目前还没有实验室方法可以预测牙科修复体的临床性能。这项工作的长期目标是开发模型和改进的诊断工具，可以用来预测树脂固位瓷修复体的相对临床寿命。在这项工作中，我们假设修复体和剩余牙齿之间的界面退化导致陶瓷断裂，从而导致临床寿命。提出的计划旨在通过结合使用简单但独特的物理疲劳模型、断口图形学方法、一种新的无损评估技术以及基于断裂力学的计算机建模来验证假设。本申请提出了一种基于系统工程的方法来研究这一问题。 目标1的目标是从实验上检验我们的假设。我们提出的模型是独一无二的，因为它允许模拟修复受到循环加载，其方式是一致地从界面开始故障，而不会累积表面接触损伤。机械和环境疲劳因素将被考虑在内。微拉伸和断口方法将被用来检验疲劳条件引起的界面退化的程度，并确定我们假设的有效性。 在目标2中，我们计划评估辅助非破坏性测试的潜在用途，以评估我们提出的假设。最先进的无损超声技术将被应用于界面的评估，并与目标1中获得的微拉伸和断口数据进行比较。如果被证明成功，这种无损技术作为临床诊断工具将具有巨大的发展潜力。在目标2中，我们还计划应用基于断裂力学的计算机模型来研究界面退化对全瓷修复体结构完整性的影响。虽然所提出的模型简单，但它将为今后开发更复杂的模型作为疲劳寿命预测工具提供基础。 拟议工作的完成将使人们对瓷修复体发生疲劳失效的过程有基本的了解，并更清楚地了解实验和分析方法的真正潜力。

DESCRIPTION: Currently there exists no laboratory methodology that can predict the clinical performance of Dental restorations. The long-range goal of this work is to develop models and improved diagnostic tools that can be used to predict the relative clinical life of resin retained ceramic restorations. In this work we posit that interface degradation between the restoration and remaining tooth contributes to ceramic fracture and thus clinical longevity. The proposed plan is designed to test the hypothesis by combining the use of a simple but unique physical fatigue model with fractographic methods, a novel nondestructive evaluation technique, and fracture mechanics based computer modeling. The application lays out a systematic engineering based approach to study this problem. The objective of Aim 1 is to experimentally test our hypothesis. The model we have proposed is unique in that it allows the simulated restoration to be subjected to cyclic loading in a manner that consistently initiates failures from the interface without the accumulation of surface contact damage. Mechanical and environmental fatigue factors will be considered. Microtensile and fractographic methods will be utilized to examine the extent of the interface degradation resulting from fatigue conditions and determine the validity of our hypothesis. In Aim 2 we plan to evaluate the potential use of adjunct non-destructive tests to evaluate our proposed hypothesis. State-of-the-art non-destructive ultrasound technology will be applied to the evaluation of the interface and compared with microtensile and fractographic data obtained in Aim 1. The non-destructive technique, if proven successful, has significant potential for future development as a clinical diagnostic tool. In Aim 2 we also plan to apply fracture mechanics based computer models to investigate the influence of interracial degradation on the structural integrity of all-ceramic restorations. Although the proposed model is simple it will provide the foundation for future development of more complex models as fatigue-life predictive tools. Completion of the proposed work should provide basic understanding of the process by which fatigue failure of ceramic restoration occurs and a clearer understanding of the true potential of the experimental and analytical approaches.