Translational Basic-Clinical Analysis of Implant-Borne Ceramic Bridge Survival

描述（由申请人提供）：该修订提案补充了K23资助，该资助专注于分析控制三单元、种植体支持、全陶瓷桥生存的体内变量。Anusavice博士是Josephine Esquivel-Upshaw博士的主要导师，Josephine Esquivel-Upshaw博士是K23奖的PI，目前正在招募128名人类受试者进行为期五年的临床研究。本R 01提案的总体目标是设计和验证一个系统过程，通过对相同三层陶瓷系统进行循环和动态疲劳试验，准确预测K23研究中要监测的陶瓷桥的存活概率。本研究将检验以下假设：根据相同陶瓷组件材料、工艺变量和热处理的动态疲劳试验数据预测的断裂存活概率与根据循环疲劳数据估计的断裂存活概率无显著差异。实验阶段将表征表面加工损伤、热处理效应、微观结构变化和环境效应的潜在影响，这些影响控制氧化锆核心陶瓷、陶瓷内衬或氟磷灰石玻璃陶瓷饰面的三单元假体的碎裂和断裂敏感性。分析阶段将采用有限元应力分析来确定模拟K23 grant种植体支持型假体中的应力分布，并使用Cares/Life软件来计算随时间变化的断裂概率。提出了以下五个目标：目标1。表征通过与K23支持的临床研究相同的表面研磨程序和用于将核心陶瓷表面中的转化氧化锆相转化回四氧化锆相的热再生工艺生产的氧化钇稳定氧化锆核心陶瓷（Y-TZP）中局部显微结构相变的类型和深度。目标2.确定氧化锆核心陶瓷表面损伤对三层氧化锆/内衬/饰面陶瓷系统界面韧性的影响。目标3。分析了水暴露对氧化锆陶瓷芯材和微晶玻璃单板的动态疲劳断裂抗力和应力腐蚀敏感性的影响。目标4。表征热处理对微观结构变化的影响，估计随时间变化的断裂概率，以及可能的失效模式。目标5。检验动态疲劳试验将提供与循环疲劳试验相当的缓慢裂纹扩展和威布尔参数的假设。因此，动态疲劳参数将产生相当的时间依赖性断裂概率，这是K23资助支持的临床研究中潜在临床性能的指标。 公共卫生相关性：这项基础临床转化研究提供了一个独特的机会，可以将牙科陶瓷系统抗断裂性的实验室研究和模拟全陶瓷修复体的生存预测与由相同材料和工艺制成的种植体支持的三单元陶瓷桥性能的正在进行的临床研究相结合。这两项研究结果的比较评价将为系统评价新陶瓷材料的成本效益体外模型提供至关重要的验证。

DESCRIPTION (provided by applicant): This revised proposal complements a K23 grant, which is focused on analyzing in vivo variables that control the survival of three-unit, implant-supported, all-ceramic bridges. Dr. Anusavice is the primary mentor for Dr. Josephine Esquivel-Upshaw, the PI of the K23 award who is currently recruiting 128 human subjects for the five-year clinical study. The overall objective of this R01 proposal is to design and validate a systematic process for accurately predicting, through cyclic and dynamic fatigue tests of the same trilayer ceramic system, the survival probabilities of the ceramic bridges to be monitored in the K23 study. This study will test the hypothesis that fracture survival probabilities predicted from dynamic fatigue test data of the same ceramic component materials, processing variables, and thermal treatments, will not be significantly different than those estimated from cyclic fatigue data. The experimental phase will characterize the potential effects of surface processing damage, thermal treatment effects, microstructural changes, and environmental effects that control the chipping and fracture susceptibility of the three-unit prostheses of either the zirconia core ceramic, the ceramic liner, or the fluorapatite glass-ceramic veneer. The analytical phase will employ finite element stress analysis to determine the stress distributions in the simulated K23 grant implant-supported prostheses and the Cares/Life software to calculate the time-dependent probability of fracture. The following five aims are proposed: Aim 1. Characterize the type and depth of localized microstructural phase changes in the yttria- stabilized zirconia core ceramic (Y-TZP) produced by same surface grinding procedures that will be used in the K23-supported clinical study and by the thermal regeneration process used to convert transformed zirconia phases in the core ceramic surface back to the tetragonal zirconia phase. Aim 2. Identify the effects of surface damage in the zirconia core ceramic on the interfacial toughness of the trilayer zirconia/liner/veneer ceramic system. Aim 3. Analyze the effect of the water exposure on the dynamic fatigue fracture resistance and stress corrosion susceptibility of the zirconia core and glass-ceramic veneer. Aim 4. Characterize the effect of thermal processing on microstructural changes, the estimated time-dependent fracture probability, and the probable mode of failure. Aim 5. Test the hypothesis that dynamic fatigue tests will provide slow crack growth and Weibull parameters comparable to those from cyclic fatigue. Thus, dynamic fatigue parameters will yield comparable time-dependent fracture probabilities that are indicators of potential clinical performance in the clinical study supported by the K23 grant. PUBLIC HEALTH RELEVANCE: This basic-clinical translational study represents a unique opportunity to integrate bench-top research on the fracture resistance of a dental ceramic system and survival predictions for simulated all-ceramic prostheses with on-going clinical research on the performance of implant-supported three-unit ceramic bridges made from the same materials and processes. The comparative evaluation of results from the two studies will provide critically important validation of a cost-effective in vitro model for systematically evaluating new ceramic materials.