Dental Cast Titanium-Ceramic Bonding

金属陶瓷修复体是现代口腔重建的重要组成部分，因为它结合了金属的强度、韧性、精度和边缘适应性与陶瓷的永久美观外观。金属-陶瓷修复体的总体临床存活率仍然远远优于全陶瓷修复体。牙科金属陶瓷系统的发展反映了两个趋势：1)寻找昂贵贵金属合金的经济替代品；2)对生物相容性材料的需求增加。由于钛具有低单位成本和生物相容性，其在口腔修复中的应用越来越多。由于其活性，熔融钛与投资材料发生反应，在铸钛表面形成反应结构，阻碍了钛-陶瓷的牢固结合。完全去除这种结构将牺牲铸件的精确配合，这在临床上是不可接受的。本研究的长期目标是改进铸钛与陶瓷的结合，并了解钛与陶瓷的结合机制。目的是通过尽量减少铸钛表面反应结构的形成来改善钛与陶瓷的结合，并确定各种因素如何促进钛与陶瓷的强结合。本研究的中心假设是，通过减少铸钛表面反应结构的形成，可以显著提高铸钛-陶瓷的附着力。该假设是基于支持性初步研究的结果制定的。这项研究的基本原理是，在接近钛凝固的温度下，用比钛氧化物更稳定的氧化物表面涂层模式可以使表面反应结构最小化。我们期望通过追求以下三个具体目标来测试中心假设并实现本应用的目标：1)确定最有效的表面涂层氧化物，以改善铸造钛-陶瓷结合；2)在模拟陶瓷烧成循环前后，对氧化表面涂层模式制备的铸态CP钛表面进行了表征；3)表征钛-陶瓷界面。我们期望通过这项研究可以改善钛-陶瓷键合的效果。该结果将为钛-陶瓷结合的基本机制提供重要的见解，并将用于钛铸造技术和改进钛-陶瓷系统的未来发展。这一发展将推动钛陶瓷系统比目前的金属陶瓷系统更具生物相容性和经济性，从而使公众受益。

Metal-ceramic restorations are an important component of modern oral reconstruction because they combine the strength, toughness, accuracy and marginal adaptation of metals with the permanent esthetic appearance of ceramics. The overall clinical survival rates for metal-ceramic restorations are still far superior to those of the all-ceramic systems. The evolution of dental metal-ceramic systems reflects two trends: 1) the search for economical alternatives to expensive noble metal alloys, and 2) the increased demand for biocompatible materials. Since titanium offers both low unit cost and biocompatibility, its use in prosthodontics has been increasing. Because of its active nature, melted titanium reacts with investment materials to form a reaction structure on the cast titanium surface, which prevents strong titanium-ceramic bonding. Complete removal of this structure will sacrifice the precise fit of the casting and is clinically unacceptable. The long- term goal of this study is to improve cast titanium-ceramic bonding and to understand titanium-ceramic bonding mechanisms. The objectives are to improve titanium-ceramic bonding by minimizing the formation of surface reaction structure on cast titanium, and to determine how various factors contribute to strong titanium- ceramic bonding. The central hypothesis of the proposed research is that cast titanium-ceramic adhesion will be significantly improved by minimizing the formation of the surface reaction structure on cast titanium. The hypothesis was formulated based on the results of supportive preliminary studies. The rationale underlying the investigation is that the surface reaction structure can be minimized by face-coating patterns with oxides that are more stable than titanium oxides at temperatures near titanium solidification. We anticipate testing the central hypothesis and achieving the objectives of this application by pursuing the following three Specific Aims: 1) to identify the most effective face-coating oxide that improves cast titanium-ceramic bonding; 2) to characterize cast CP titanium surfaces prepared from oxide face- coated patterns before and after the simulated porcelain firing cycles; and 3) to characterize the titanium-ceramic interfaces. It is our expectation that improved titanium-ceramic bonding will be achieved as a result of this study. The results will provide significant insight into the fundamental mechanisms of titanium- ceramic bonding and will be used for future development of titanium casting techniques and improved titanium-ceramic systems. This development will advance the titanium-ceramic systems that are more biocompatible and economical than current metal-ceramic systems, thereby benefitting the general public.