EFFECT OF MICROSTRUCTURE ON WEAR OF DENTAL CERAMICS

陶瓷材料在牙科应用中获得了突出的地位， 特别是在牙冠和咬合面的修复中。 磨损 修复体和与陶瓷修复体相对的釉质通常 一个限制修复寿命的关键因素。 然而，可用的 关于这些材料的磨损性能的数据和信息有限。 特别是，陶瓷微观结构，口腔环境， 机械加工对磨损的影响，以及天然釉质的磨损行为， 陶瓷修复，是未知的。 该项目的目标是 研究显微结构对牙科陶瓷磨损的影响， 相反的搪瓷，并评估加工损伤的可能影响 和环境对所选牙科陶瓷磨损的影响。 六个具体目标 研究内容如下：（1）确定显微组织对磨损的影响 为了确定最佳磨损性能的最佳微观结构，（2）比较 微裂纹磨损机制与损伤形成过程 机械加工中的疲劳断裂和材料去除过程; 量化加工损伤的影响（包括表面粗糙度， 表面完整性和玷污层）对所选牙科陶瓷磨损的影响， (4)评估环境（空气、水和人工唾液）的影响 对所选牙科陶瓷磨损的影响，（5）评价表面处理对陶瓷磨损的影响。 化学回火对所选牙科陶瓷磨损的影响;（6）检查 天然牙釉质对不同陶瓷微结构的磨损试验， 各种环境。 该项目的成果将有助于 为先进材料的选择和微观结构设计提供了指导 牙科修复材料的最佳性能的基础上磨损 修复和相对的天然釉质。 中的一个重要问题 这项研究是微观结构对 磨损、疲劳和机械加工。 因此，微破裂过程 将比较疲劳（项目2）和机械加工（项目1）中涉及的 与那些观察磨损制定一些准则，建立 最佳的微观结构，以获得最佳的磨损性能， 影响疲劳和机械加工性。

Ceramic materials are gaining a prominent position in dental applications, particularly in the restoration of crowns and occlusal surfaces. Wear of the restoration and the enamel opposing the ceramic restoration is often a key factor limiting the life of the restoration. However, the available data and information on wear performance of these materials are limited. Particularly, the effects of ceramic microstructure, oral environment, and machining on wear, and the wear behavior of natural enamel opposing the ceramic restoration, are not known. The objectives of this project are to determine the effect of microstructure on wear of dental ceramics and the opposing enamel, and to evaluate the possible effects of machining damage and environment on wear of selected dental ceramics. Six specific aims will be investigated: (1) determine the effect of microstructure on wear to define an optimum microstructure for best wear performance, (2) compare the microfracture wear mechanisms with the process of damage formation in fatigue and fracture and the material removal process in machining, (3) quantify the effects of machining damage (including surface roughness, surface integrity, and smear layers) on wear of selected dental ceramics, (4) evaluate the effect of environment (air, water, and artificial saliva) on wear of selected dental ceramics, (5) evaluate the effect of surface chemical tempering on wear of selected dental ceramics, and (6) examine wear of natural enamel tested against different ceramic microstructures in various environments. The results of this project will be instrumental in providing guidelines for selection and microstructural design of advanced dental restorative materials for an optimum performance based on wear of the restoration and the opposing natural enamel. An important issue in this research is the interplay between the effects of microstructure on wear, fatigue, and machining. Therefore, the microfracture processes involved in fatigue (Project 2) and machining (Project 1) will be compared with those observed for wear to develop some guidelines for establishing an optimum microstructure for best wear performance, without adversely affecting fatigue and machinability.