Toward novel translucent and strong nanostructured dental zirconia

项目概要/摘要 实现半透明性和强度是陶瓷修复材料的重要要求。 不幸的是，这些属性通常是相互排斥的。瓷基和微晶玻璃材料 具有较高的半透明度但较低的强度，因此容易过早失效。氧化锆基 陶瓷更坚固、更坚韧，但透光性较差。因此迫切需要开发 半透明且坚固的陶瓷，可用于下一代性能更好的修复材料。据此， 该项目的长期目标是开发美观、坚固且耐磨的纳米晶氧化钇- 用于牙科和生物医学应用的稳定四方氧化锆多晶 (Y-TZP)。整体 该应用的目标是：(1) 通过优化纳米晶 Y-TZP 的半透明度和强度 成分和微观结构定制； (2) 阐明 Y-TZP 在 纳米级和微米级。据我们所知，该提案是第一个系统地解决这些问题的提案 问题。中心假设是纳米晶 Y-TZP 表现出改善的半透明度、强度和 相对于微晶同类产品，磨损性降低。这一假设的提出是基于 申请人实验室得出的初步结果。为了检验这个假设，我们将追求 3 个具体的 目标：（1）优化纳米结构Y-TZP的半透明度和强度； (2) 阐明依赖性 Y-TZP 微观结构的半透明度、强度退化和韧性； (3) 确定电阻 使用嘴部运动模拟器研究纳米结构 Y-TZP 的疲劳和磨损。该方法具有创新性 因为它脱离了现状，开发了一种新型纳米晶Y-TZP，具有改进的性能 使用新颖的加工方法实现半透明性和抗断裂性并降低磨损性。的 拟议的研究意义重大，因为它将氧化锆的临床适应症扩展到了美容区域，并且 承诺微创治疗。这种方法将延长假牙寿命并保护牙齿 结构，从而减少纠正过早故障所花费的金钱和时间。作为一项附加福利， 纳米晶 Y-TZP 的开发将为建立更广泛的相关性提供模型系统 机械性能和晶粒尺寸之间的关系，从而将经典断裂力学定律扩展到 纳米级域。

Project Summary/Abstract The attainment of both translucency and strength is a vital requirement for ceramic restorative materials. Unfortunately, these properties are often mutually exclusive. Porcelain-based and glass-ceramic materials have higher translucency but lower strength, and are thus susceptible to premature failure. Zirconia-based ceramics are stronger and tougher but have poor translucency. There is therefore an urgent need to develop translucent and strong ceramics for the next generation of better-performing restorative materials. Accordingly, the long-term goal of this project is to develop esthetic, strong, and abrasion-resistant nanocrystalline yttria- stabilized tetragonal zirconia polycrystals (Y-TZP) for dental and biomedical applications. The overall objectives in this application are: (1) optimize the translucency and strength of nanocrystalline Y-TZP via compositional and microstructural tailoring; and (2) elucidate microstructure-mechanical properties of Y-TZP at the nano and microscale levels. To our knowledge, this proposal is the first to systematically address these questions. The central hypothesis is that nanocrystalline Y-TZP exhibits improved translucency, strength and reduced abrasiveness relative to its microcrystalline counterparts. This hypothesis is formulated on the basis of preliminary results produced in the applicants’ laboratories. To test this hypothesis, we will pursue 3 specific aims: (1) Optimize nanostructured Y-TZP for translucency and strength; (2) Elucidate the dependence of translucency, strength degradation and toughness on Y-TZP microstructure; and (3) Determine resistance to fatigue and wear of nanostructured Y-TZP using a mouth-motion simulator. The approach is innovative because it departs from the status quo by developing a new form of nanocrystalline Y-TZP with improved translucency and fracture resistance and reduced abrasiveness using novel processing methodologies. The proposed research is significant because it extends clinical indications for zirconia to the esthetic zone and promises minimally invasive treatments. Such an approach will prolong prosthetic lifetimes and preserve tooth structure, thus reducing money and time spent correcting premature failures. As an adjunct benefit, the development of nanocrystalline Y-TZP will provide a model system for establishing a broader correlation between mechanical properties and grain size, thus extending classical fracture mechanics laws into the nanoscale domain.