Toward novel translucent and strong nanostructured dental zirconia

项目概要/摘要 达到透明度和强度是陶瓷修复材料的重要要求。 不幸的是，这些属性往往是相互排斥的。陶瓷基和玻璃陶瓷材料 具有较高的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，但透光性差。因此，迫切需要制定 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，委员会认为， 该项目的长期目标是开发美观、坚固、耐磨的纳米晶氧化钇， 稳定的四氧化锆多晶体（Y-TZP）用于牙科和生物医学应用。整体 本申请的目的是：（1）通过以下方法优化纳米晶Y-TZP的半导体性能和强度： 成分和微观结构剪裁;和（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，这项建议是第一个系统地解决这些问题的建议。 问题.中心假设是纳米晶Y-TZP表现出改善的半透明性、强度和热稳定性。 相对于其微晶对应物降低的研磨性。这一假设是根据以下几点提出的： 申请人实验室得出的初步结果。为了验证这一假设，我们将追踪3个具体的 目的：（1）优化纳米结构Y-TZP的透明度和强度;（2）阐明纳米结构Y-TZP的 Y-TZP显微组织上的韧性、强度退化和韧性;以及（3）确定抗 疲劳和磨损的纳米结构的Y-TZP使用口腔运动模拟器。方法是创新的 因为它通过开发一种新形式的纳米晶Y-TZP而脱离了现状， 使用新的加工方法，提高透明度和抗断裂性，并降低磨损性。的 所提出的研究是重要的，因为它将氧化锆的临床适应症扩展到美学区， 承诺微创治疗。这种方法将延长假体的使用寿命并保护牙齿 结构，从而减少纠正过早故障所花费的金钱和时间。作为一种附加的好处， 纳米晶Y-TZP的发展将为建立更广泛的相关性提供一个模型系统 力学性能和晶粒尺寸之间的关系，从而将经典的断裂力学定律扩展到 nanoscale domain

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.