Novel coatings to minimize surface degradation and fracture susceptibility of dental ceramics

项目摘要/摘要 这项建议的重点是确定保护性涂层在最大限度地减少表面退化方面的有效性 玻璃陶瓷贴面以及最大限度地减少陶瓷假体的碎屑。这份R01提案是 设计分析了三种微晶玻璃贴面材料的化学耐久性和抗断裂性能 通过体外模拟实验确定具有不同微观结构的新型pH循环 方法学将可靠地模拟受口腔内pH波动控制的化学降解 环境。这项研究计划的长期目标是开发耐骨折和化学稳定性 (耐用)，用于贴面牙科陶瓷假体的牙科陶瓷涂层。这一点的中心假设是 项目是牙科陶瓷贴面将保持最小的表面退化，并保持或增加其 表观强度时，涂有优化的保护性、粘附性表面层。 这一独特的翻译研究项目将应用于陶瓷的腐蚀测试和损伤分析 贴面材料通过体外模拟。我们将采用一种新的pH循环方法，这将 使用三种从酸性到碱性的交替pH缓冲溶液，同时进行间歇性磨损。 这种循环机制有效地模拟了口服液的pH值水平的波动，并可以更准确地 测试陶瓷材料的化学耐久性。更重要的是，我们将建立优化的有效性 等离子体增强涂层气相沉积技术在最大限度减少涂层中的应用 提高陶瓷的耐腐蚀性和抗裂性。我们将分析表面成分和 用X射线光电子能谱(XPS)、环境扫描电子能谱(XPS)研究地形变化 显微镜(ESEM)、能量色散X射线分析(EDAX)、数字显微镜和3D激光扫描 磨损分析。我们提出以下目的来检验我们的中心假说：目标1：检验假说 玻璃陶瓷贴面经历交替的溶解过程(选择性淋洗和完全溶解)，如 导致组成变化和表面快速降解的pH环境循环的函数 玻璃相；目标2：检验玻璃双向抗折强度显著降低的假设-- 陶瓷贴面将作为模拟口腔环境低和高pH或交替出现的结果 模拟咬合力与间歇性磨损或两者的组合；目标3：测试假设 保护涂层可以优化，以实现良好的耐低pH和高pH环境，理想 与陶瓷基板粘合，良好的耐磨性和抗折性，以及适当的美观；目标4：测试 假设最佳的防护涂层将显著降低玻璃的体外腐蚀率。 由pH波动引起的表面成分变化减少所证明的陶瓷贴面 和磨损因素，并保持或显著增加其“表观”的双向弯曲强度。

PROJECT SUMMARY/ABSTRACT This proposal is focused on establishing the efficacy of protective coatings in minimizing surface degradation of glass-ceramic veneers as well as minimizing chipping of ceramic-ceramic prostheses. This R01 proposal is designed to analyze the chemical durability and fracture resistance of three glass-ceramic veneering materials with different microstructures through in vitro simulation tests and to determine whether a novel pH cycling methodology will reliably simulate the chemical degradation that is controlled by pH fluctuations in the oral environment. The long-term goal of this research program is to develop fracture-resistant and chemically stable (durable), dental ceramic coatings for veneered dental ceramic prostheses. The central hypothesis of this project is that dental ceramic veneers will sustain minimal surface degradation and maintain or increase their apparent strength when coated with an optimized protective, adherent surface layer. This unique, translational research project will apply corrosion testing and damage analysis of ceramic veneering materials through in vitro simulation. We will employ a novel pH cycling methodology, which will apply three sequences of alternating pH buffer solutions from acidic to alkali, alongside intermittent abrasion. This cycling mechanism effectively simulates the fluctuating pH levels of oral fluids and can more accurately test chemical durability of ceramic materials. More importantly, we will establish the effectiveness of optimized protective coatings deposited using plasma enhanced coating vapor deposition technology in minimizing ceramic corrosion and improving fracture resistance. We will analyze the surface composition and topographical changes using x-ray photoelectron spectroscopy (XPS), environmental scanning electron microscopy (ESEM), energy dispersive x-ray analysis (EDAX), digital microscopy, and 3D laserscanning for wear analysis. We propose the following aims to test our central hypothesis: Aim 1: Test the hypothesis that glass-ceramic veneers undergo an alternating dissolution process (selective leaching and total dissolution) as a function of cycling pH environments resulting in compositional changes and rapid surface degradation of the glass phase; Aim 2: Test the hypothesis that a significant decrease in the biaxial flexural strength of glass- ceramic veneers will occur as a result of a simulated oral environment of alternating low and high pH or simulated occlusal forces with intermittent abrasion or a combination of both; Aim 3: Test the hypothesis that a protective coating can be optimized to achieve good resistance to low pH and high pH environments, ideal bonding to the ceramic substrate, good abrasion and fracture resistance and proper esthetics; Aim 4: Test the hypothesis that the optimal protective coating will significantly decrease the in vitro corrosive rate of glass- ceramic veneers as evidenced by a reduction in surface compositional changes caused by fluctuations in pH and abrasion factors, and maintain or significantly increase their “apparent” biaxial flexural strength.