Understanding the microstructural bonding mechanisms between Y-TZP and veneering ceramic

了解 Y-TZP 和饰面陶瓷之间的微观结构结合机制

• 批准号: RGPIN-2016-05178
• 负责人: Butler, Sheila
• 金额: $ 1.82万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=750693
• 关键词: Understanding; microstructural; bonding; mechanisms; between

Dental veneered zirconia-based core restorations have been used widely to date. The zirconia core is layered with a porcelain veneer material to achieve suitable esthetics. However, zirconia-based restorations can create clinical issues such as chipping or fracture of the porcelain veneered layer. Previous studies have reported a significant incidence of veneer failures such as delaminations, chipping and cracking. This fracture behavior could be attributed to the poor veneer/core interface bond strength, elastic modulus mismatch between the core material and the veneer, coefficient of thermal expansion mismatch between the core and the veneer, weak porcelain strength and thermal procedure which could introduce residual stress induced by cooling rate and/or sintering at high temperatures. To improve the compatibility at the interface between veneer and core, and to avoid premature failure, the interface zirconia/porcelain should be better understood. The proposed research will investigate the detailed mechanism for the adhesion at the interface zirconia/porcelain to develop a feasible solution to improve the bonding between these two materials, using both molding techniques (the layering technique and the press technique). The thermal stresses will be also evaluated. The main objectives of this study are to characterize the interaction between porcelain and zirconia then, materials or new designs will be developed based on the results. Therefore, better bonding stability between porcelain veneer and zirconia core of an all-ceramic restoration can be achieved. The adhesion of porcelain veneer to zirconia is fundamental for the success of the zirconia-based restorations. After determining the new protocol and/or design to fabricate zirconia-based restorations, mechanical tests will be performed.Different tests will be carefully conducted to describe the microstructural mechanisms of zirconia/porcelain bond. The tests are SEM, EDS, Electron Backscatter Diffraction (EBSD). Furthermore, microstructures, texture, defects, grain morphology and deformation will also be evaluated by EBSD. In addition, the Focused Ion Beam microscopy (FIB) will be used to prepare thin specimens for the TEM and for Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS). Auger Microprobe will contribute to the determination of 2D and 3D elemental distributions on surfaces with high spatial resolution. The bond formation of the zirconia to porcelain will also be examined by XPS.The outcome of the research is to provide the dental laboratories with a new protocol to fabricate dental veneered zirconia-based core restorations in order to improve the success rate of this type of dental restoration. The new protocol will be based on the detailed bond mechanisms at the zirconia/porcelain interface obtained from the results of this study. Over 5 years, I will train 3 graduate students.

迄今为止，基于氧化锆的牙科贴面核心修复体已被广泛使用。氧化锆芯层上覆盖有瓷贴面材料，以达到合适的美观效果。然而，氧化锆基修复体可能会产生临床问题，例如瓷贴面层碎裂或断裂。先前的研究报告了单板失效的显着发生率，例如分层、碎裂和开裂。这种断裂行为可能是由于单板/芯材界面粘合强度差、芯材与单板之间的弹性模量不匹配、芯材与单板之间的热膨胀系数不匹配、瓷强度弱以及可能引入残余应力的热加工过程造成的。由冷却速率和/或高温烧结引起。为了提高单板和芯材之间界面的相容性，并避免过早失效，应该更好地了解氧化锆/陶瓷界面。拟议的研究将研究氧化锆/陶瓷界面粘合的详细机制，以开发一种可行的解决方案，使用两种成型技术（分层技术和压制技术）来改善这两种材料之间的粘合。还将评估热应力。这项研究的主要目的是表征瓷器和氧化锆之间的相互作用，然后根据结果开发材料或新设计。因此，全瓷修复体的瓷贴面和氧化锆核心之间可以获得更好的结合稳定性。瓷贴面与氧化锆的粘合力是氧化锆修复体成功的基础。在确定制造氧化锆基修复体的新方案和/或设计后，将进行机械测试。将仔细进行不同的测试来描述氧化锆/瓷粘结的微观结构机制。测试包括 SEM、EDS、电子背散射衍射 (EBSD)。此外，微观结构、织构、缺陷、晶粒形态和变形也将通过 EBSD 进行评估。此外，聚焦离子束显微镜 (FIB) 将用于制备 TEM 和飞行时间二次离子质谱 (TOF-SIMS) 的薄样品。俄歇微探针将有助于以高空间分辨率确定表面上的 2D 和 3D 元素分布。氧化锆与瓷的粘合形成也将通过 XPS 进行检查。该研究的结果是为牙科实验室提供一种新的方案来制造牙科贴面氧化锆基核心修复体，以提高此类修复的成功率牙齿修复。新协议将基于从本研究结果中获得的氧化锆/瓷界面的详细粘合机制。 5年多的时间里，我将培养3名研究生。