Toward novel translucent and strong nanostructured dental zirconia

项目摘要/摘要 达到半透明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 具有较高的半透明性，但强度较低，因此容易过早失效。氧化锆基 陶瓷更坚固、更坚韧，但半透明性很差。因此，迫切需要发展 半透明和坚固的陶瓷，用于下一代性能更好的修复材料。因此， 该项目的长期目标是开发美观、坚固和耐磨的纳米氧化钛。 稳定的四方氧化锆多晶(Y-TZP)，用于牙科和生物医学应用。整体而言 本应用的目标是：(1)通过优化纳米晶Y-TZP的半透明性和强度 成分和显微组织剪裁；以及(2)阐明Y-TZP的微观结构-力学性能 纳米级和微米级。据我们所知，这项提案是第一次系统地解决这些问题。 问题。中心假设是纳米晶Y-TZP表现出更好的半透明性、强度和 与微晶材料相比，磨损性降低。这一假设是在以下基础上提出的 申请者实验室产生的初步结果。为了验证这一假设，我们将进行3个具体的 目的：(1)优化纳米结构的Y-TZP的半透明性和强度；(2)阐明 Y-TZP显微组织的半透明性、强度退化和韧性；以及(3)确定抗 基于口腔运动模拟器的纳米Y-TZP疲劳与磨损研究。这种方法是创新的 因为它通过开发一种新的形式的纳米晶Y-TZP来改变现状 采用新的加工方法，具有半透明性和耐折断性，并减少了磨损性。这个 拟议的研究具有重要意义，因为它将氧化锆的临床适应症扩展到美观区和 承诺进行微创治疗。这种方法将延长修复体的寿命并保存牙齿。 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的发展将为建立更广泛的关联提供一个模型系统 力学性能与晶粒度之间的关系，从而将经典断裂力学定律扩展到 纳米尺度的领域。

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.