THIN FILM SURFACE COATINGS FOR TOUGHENED DENTAL CERAMICS

描述(改编自研究人员摘要)：非金属材料的发展 (例如，汞合金替代品)修复材料是一项高度优先的研究 由于与金属废物和处置相关的环境问题。 陶瓷是取代金属基修复剂的耐人寻味的候选者 材料。牙科应用中的陶瓷提供了极好的化学物质 耐用性、耐磨性、生物兼容性、环境友好性和 美学。然而，全瓷修复体的广泛使用受到以下因素的阻碍 与边缘骨折抗力和临床寿命有关的问题。 以前的研究(凯利等人，；汤普森等人，1994年)发现 全瓷修复体沿内表面起裂的临床研究 (例如，粘合表面)几乎是唯一的。因此，至关重要的是 克服断裂问题，如果这些材料要得到广泛的 接受。这项研究的总体目标是生产出坚韧的、 等离子镀膜抗疲劳陶瓷修复体的研究 陶瓷表面涂层。提出了四个具体目标。目标1建议 对溅射沉积薄膜的应用假设进行检验的研究 涂层将增强传统商用车的断裂和抗疲劳性能 牙科陶瓷材料至少减少50%。目标2建议进行研究，以测试 假设溅射沉积了细晶(小于1微米)的薄膜 微结构将产生显著的衬底/薄膜结构 比具有柱状结构的薄膜获得的断裂韧性更大 颗粒结构。目标3建议进行研究，以检验存在的假设 溅射沉积的薄膜陶瓷涂层不会对 牙体粘固剂的界面韧性或光学特性 (透过率、折射率和L*a*b*颜色参数) 修复术。目标4建议检验多层和/或 成分渐变的薄膜表面涂层将产生基片/薄膜 具有比所实现的更大的断裂韧性的薄膜结构 具有单一成分的薄膜。候选沉积材料包括氧化铝， 将创建ZrO2、MgAl2O4、AlN、Si3N4、SiC和类钻石C涂层 采用射频磁控溅射沉积。多层和成分分级 将使用多目标和反应溅射沉积来创建涂层。 断裂韧性将由受控裂纹断裂强度决定 裂缝萌生缺陷的方法和断口评价。疲劳 将通过开发寿命预测配置文件来表征行为。扫描电子显微镜， 利用扫描电子显微镜和原子力显微镜对界面和微观结构进行了表征 沉积薄膜。

DESCRIPTION (adapted from Investigator's abstract): Development of non-metallic (e.g., amalgam-substitute) restorative materials is a high research priority due to environmental concerns associated with metals waste and disposal. Ceramics are an intriguing candidate for replacing metal-based restorative materials. Ceramics in dental applications provide excellent chemical durability, wear resistance, biocompatibility, environmental friendliness, and esthetics. However, widespread all-ceramic restoration use has been hindered by concerns related to marginal fracture resistance and clinical longevity. Previous studies (Kelly et al., 1989; Thompson et al., 1994) found that clinical fracture of all-ceramic restorations initiated along internal surfaces (e.g., bonded surfaces) almost exclusively. It is therefore critical to overcome fracture problems if these materials are to gain widespread acceptance. The overall goal of this research is to produce tough, fatigue-resistance ceramic restorations by applying thin film plasma-deposited ceramic surface coatings. Four specific aims are proposed. Aim 1 proposes studies to test the hypothesis that application of sputter deposited thin film coatings will enhance fracture and fatigue resistance of traditional commercial dental ceramic materials by at least 50%. Aim 2 proposes studies to test the hypothesis that sputter deposited thin films with fine-grained (less than 1 um microstructures will yield substrate/thin film constructs with significantly greater fracture toughness than achieved with thin films possessing columnar grain structures. Aim 3 proposes studies to test the hypothesis that presence of sputter deposited thin film ceramic coatings will not adversely affect the interfacial toughness with dental luting cements or the optical characteristics (transmittance, index of refraction, and L*a*b* color parameters) of modified restorations. Aim 4 proposes to test the hypotheses that multilayer and/or compositionally graded thin film surface coatings will yield a substrate/thin film construct with significantly greater fracture toughness than is achieved with unicompositional thin films. Candidate deposition materials include Al2O3, ZrO2, MgAl2O4, AlN, Si3N4, SiC, and diamond-like C. Coatings will be created using RF magnetron sputter deposition. Multilayer and compositionally graded coatings will be created using multiple target and reactive sputter deposition. Fracture toughness will be determined by controlled-flaw fracture strength methods and fractographic evaluation of fracture-initiating flaws. Fatigue behavior will be characterized by developing lifetime prediction profiles. SEM, TEM, and AFM will be used to characterize interfaces and microstructures of deposited thin films.