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，该资助侧重于分析控制三单元、种植体支持的全陶瓷桥存活的体内变量。Anusavice博士是Josephine Esquivel-Upshaw博士的主要导师，Josephine Esquivel-Upshaw博士是K23奖的首席研究员，目前正在为这项为期五年的临床研究招募128名人类受试者。本R01提案的总体目标是设计并验证一个系统的过程，通过对同一三层陶瓷体系的循环和动态疲劳试验，准确预测K23研究中监测的陶瓷桥的生存概率。本研究将验证这样一个假设，即从相同陶瓷构件材料、加工变量和热处理的动态疲劳试验数据中预测的断裂存活概率与从循环疲劳数据中估计的断裂存活概率没有显著差异。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影响的潜在影响，这些影响控制了氧化锆核心陶瓷、陶瓷衬里或氟磷灰石玻璃陶瓷贴面的三单元假体的切屑和断裂敏感性。分析阶段将采用有限元应力分析来确定模拟K23 grant种植体支撑假体的应力分布，并使用Cares/Life软件计算骨折的时间相关概率。提出以下五个目标：目标1。表征氧化钇稳定氧化锆核心陶瓷（Y-TZP）局部微观结构相变的类型和深度，该陶瓷是由k23支持的临床研究中使用的相同表面研磨工艺生产的，并通过热再生过程将核心陶瓷表面的氧化锆相转换回四方氧化锆相。目标2。确定氧化锆核心陶瓷表面损伤对氧化锆/衬里/贴面陶瓷体系界面韧性的影响。目标3。分析了水对氧化锆芯和玻璃陶瓷贴面的动态疲劳断裂抗力和应力腐蚀敏感性的影响。目标4。表征热加工对微观组织变化的影响，估计的随时间变化的断裂概率，以及可能的失效模式。目标5。验证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可比较的随时间变化的骨折概率，这是K23基金支持的临床研究中潜在临床表现的指标。

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.