Thin Film Surface Coating for Toughened Dental Ceramics

描述：开发非金属（例如，汞替代物）修复材料由于与金属废物和处置相关的环境问题而成为高度优先的研究。陶瓷是替代金属基修复材料的理想候选材料。陶瓷具有优异的化学耐久性、耐磨性、生物相容性、环境友好性和美观性。然而，全瓷修复体的广泛使用受到了边缘抗折性和临床寿命的影响。以前的研究发现，全陶瓷涂层的临床断裂是沿着沿着内表面（例如，粘合表面）几乎完全。因此，如果这些材料要获得广泛的接受，克服断裂问题是至关重要的。这项持续研究的总体目标是通过实施RF等离子体溅射沉积薄膜陶瓷表面涂层，最大限度地减少或消除表面缺陷的灾难性影响，从而开发更坚固、更耐疲劳的全陶瓷牙科涂层。到目前为止，在最初资助的NIH拨款范围内进行的研究主要集中在沉积膜的微观结构控制和评估它们对改性陶瓷基材机械行为的影响。ZrO 2已被确定为最合适的薄膜涂层材料。此外，已经发现，ZrO 2薄膜对与改性牙科陶瓷表面的结合或对半透明陶瓷的美学外观没有有害影响。这项持续研究的具体目标是：（1）测试溅射沉积的ZrO 2薄膜内的残余应力状态和分布可以通过操作沉积参数可再现地控制以产生具有可预测的抗断裂性的构造的假设，（2）测试具有交替的高模量层和低模量层的多层薄膜的沉积可用于制备基底/薄膜层压结构的断裂韧性显著高于单层薄膜，以及（3）测试溅射沉积ZrO 2薄膜的加入将显著增强由传统市售牙科陶瓷材料制成的样本的抗疲劳性的假设。这项技术需要进一步研究，以建立一个更详细的了解之间的关系，沉积参数，薄膜微观结构，和短期和长期的机械性能的改性陶瓷，如果临床有效的过程是要开发。

DESCRIPTION: 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 ideal candidate for replacing metal-based restorative materials. Ceramics provide excellent chemical durability; wear resistance, biocompatibility, environmental friendliness, and esthetics. Nevertheless, widespread all-ceramic restoration use has been hindered by concerns related to marginal fracture resistance and clinical longevity. Previous studies 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 continued research is to develop tougher, more fatigue-resistant all-ceramic dental restorations by minimizing or eliminating catastrophic effects of surface flaws through the implementation of RF-plasma sputter deposited thin-film ceramic surface coatings. Research conducted to date within the initial funded NIH grant has focused on microstructural control of deposited films and assessing their affect on the mechanical behavior of modified ceramic substrates. ZrO2 has been identified as the most appropriate thin film coating material. In addition, it has been found that ZrO2 thin-films produce no deleterious effect on bonding to a modified dental ceramic surface, or on the esthetic appearance of a translucent ceramic. The Specific Aims of this continued research are to: (1) test the hypothesis that the residual stress state and distribution within sputter deposited ZrO2 thin-films can be reproducibly controlled through manipulation of deposition parameters to produce constructs with predictable fracture resistance, (2) test the hypothesis that deposition of multi-layered thin-films with alternating high and low modulus layers can be used to produce substrate/thin-film laminate constructs with significantly greater facture toughness than is achieved with single-layer thin films, and (3) test the hypothesis that incorporation of sputter deposited ZrO2 thin-films will significantly enhance the fatigue resistance of specimens fabricated from traditional commercially available Dental ceramic materials. This technology needs further study to establish a more detailed understanding of the relationships between deposition parameters, thin-film microstructures, and short and long-term mechanical behavior of modified ceramics if a clinically efficacious process is to be developed.