Yttria-partially stabilized zirconia: using the transformed layer as a permeable membrane for the infiltration of materials

氧化钇部分稳定氧化锆：利用转化层作为渗透材料的渗透膜

• 批准号: RGPIN-2018-04979
• 负责人: DeSouza, Grace
• 金额: $ 2.04万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=682976
• 关键词: Yttria; partially; stabilized; zirconia; using

Three-mol% Yttria-tetragonal zirconia polycrystal (3Y-TZP) is a unique ceramic for dental application, due to the transformability of the crystallographic structures (from tetragonal to monoclinic t-m), which is responsible for the transformation-toughening mechanism. However, conditions such as body temperature, cyclic loading and humidity cause the tetragonal-to-monoclinic (t-m) phase transformation to happen at a faster pace, changing the 3Y-TZP's characteristics in the original processed state. This 3Y-TZP transformed zone runs from the surface down to the bulk of the material. Furthermore, 3Y-TZP is considered biologically inert, which restricts its application as a dental implant due to the lack of osseointegration. 3Y-TZP is also chemically inert, resulting in lack of chemical interaction with active monomers for bonding to the tooth structure and to other ceramic materials. To improve the bonding between 3Y-TZP and other substrates, most of the studies done so far attempted to increase surface roughness through surface alumina blasting. However, this procedure compromises the mechanical performance of 3Y-TZP and bond strength results are inconclusive. 3Y-TZP aging results in the combination of surface m spots and grain pull-out, and a microcracked layer underneath as a consequence of the dislodgement of the martensitic plates. Our preliminary data indicate that the 3Y-TZP t-m transformed layer is porous and may be used for the infiltration of thin films. Therefore, the long-term objective of my research program is to develop a ceramic-based material that presents reliable biomechanical performance for dental application. In the short-term, my goal is to develop a hybrid interface between 3Y-TZP t-m transformed layer and silicon/titanium oxides using RT-ALD. Therefore, the 3 main objectives of this research program are: 1: to define the ideal thickness of the 3Y-TZP t-m transformed layer as a function of porosity and mechanical properties; 2: to develop a method to produce a hybrid interface between 3Y-TZP transformed layer and silica-based nanofilm to enable better bonding between 3Y-TZP and other materials; 3: To develop a method to produce a hybrid interface between 3Y-TZP transformed layer and titania-based nanofilm to enable better osseointegration. The characterization of the 3Y-TZP transformed layer is of interest to a large scientific community, in the continuous search for more stable and more receptive zirconia-based substrates. It will also impact the training of high-qualified personnel, by proposing a multidisciplinary approach in a well-equipped environment.

3 Y-TZP（3 Y-TZP）是一种独特的牙科陶瓷材料，其晶体结构具有从四方相到单斜相的相变增韧机制。然而，诸如体温、循环载荷和湿度的条件导致四方到单斜（t-m）相变以更快的速度发生，改变了3 Y-TZP在原始处理状态下的特性。该3 Y-TZP转化区从材料的表面向下延伸到材料的本体。此外，3 Y-TZP被认为是生物惰性的，由于缺乏骨整合，这限制了其作为牙科种植体的应用。3 Y-TZP也是化学惰性的，导致缺乏与活性单体的化学相互作用，以结合到牙齿结构和其他陶瓷材料。为了改善3 Y-TZP与其他基材之间的结合，迄今为止所做的大多数研究都试图通过表面氧化铝喷砂来增加表面粗糙度。然而，该程序损害了3 Y-TZP的机械性能，并且粘结强度结果是不确定的。3 Y-TZP时效导致表面m点和晶粒拔出的组合，以及作为马氏体板移位的结果的下面的微裂纹层。我们的初步数据表明，3 Y-TZP t-m转化层是多孔的，可以用于薄膜的渗透。因此，我的研究计划的长期目标是开发一种陶瓷基材料，为牙科应用提供可靠的生物力学性能。在短期内，我的目标是使用RT-ALD在3 Y-TZP t-m转化层和硅/钛氧化物之间开发混合界面。因此，本研究计划的3个主要目标是：1：定义3 Y-TZP t-m转化层的理想厚度作为孔隙率和机械性能的函数; 2：开发一种方法来产生3 Y-TZP转化层和基于二氧化硅的纳米膜之间的混合界面，以使得3 Y-TZP和其他材料之间能够更好地结合; 3：开发一种在3 Y-TZP转化层和二氧化钛基纳米膜之间产生混合界面的方法，以实现更好的骨整合。 3 Y-TZP转化层的表征是一个大的科学界感兴趣的，在不断寻找更稳定和更容易接受的氧化锆基衬底。它还将通过在设备齐全的环境中提出多学科方法，对高素质人员的培训产生影响。