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

描述(由申请人提供)：这项修订后的提案是对K23基金的补充，K23基金的重点是分析体内控制三个单元、种植体支持的全陶瓷桥存活的变量。Anusavice博士是Josephine Esquivel-Upshaw博士的主要导师，Josephine Esquivel-Upshaw博士是K23奖项的PI，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。R01提案的总体目标是设计和验证一个系统流程，通过对同一三层陶瓷系统的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。这项研究将检验这样一种假设，即根据相同陶瓷部件材料、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没有显著差异。实验阶段将描述表面处理损伤、热处理效果、微结构变化和环境影响的潜在影响，这些影响控制氧化锆核陶瓷、陶瓷衬里或氟磷灰石玻璃陶瓷贴面的三单元假体的碎屑和断裂敏感性。分析阶段将使用有限元应力分析来确定模拟K23 Grant种植体支持的假体中的应力分布，并使用CARES/Life软件来计算与时间相关的骨折概率。提出以下五个目标：目的1.表征Y3稳定氧化锆芯陶瓷(Y-TZP)的局域微结构相变化的类型和深度。Y-TZP是由K23支持的临床研究中使用的相同表面研磨工艺和将芯陶瓷表面转变的氧化锆相转化回四方氧化锆相的热再生工艺生产的。目的2.研究氧化锆芯陶瓷表面损伤对氧化锆/衬里/贴面三层陶瓷系统界面韧性的影响。目的3.分析水暴露对氧化锆芯和微晶玻璃贴面的动态疲劳断裂抗力和应力腐蚀敏感性的影响。目的4.表征热处理对微结构变化的影响、估计的随时间变化的断裂概率以及可能的失效模式。目的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与时间相关的可比骨折概率，这些概率是K23拨款支持的临床研究中潜在临床表现的指标。 公共卫生相关性：这项基础-临床转化研究是一个独特的机会，可以将关于牙科陶瓷系统的抗折性的台式研究和模拟全瓷修复体的存活预测与正在进行的关于由相同材料和工艺制成的植入体支持的三单元陶瓷桥的性能的临床研究相结合。对这两项研究结果的比较评估将为系统评价新陶瓷材料的体外经济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.