Dental Cast Titanium-Ceramic Bonding

金属烤瓷修复体是现代口腔修复的重要组成部分，因为它们将金属的强度、韧性、准确性和边缘适应性与陶瓷的永久美学外观结合在一起。金属烤瓷修复体的总体临床存活率仍远远优于全瓷修复体。牙科金属陶瓷系统的发展反映了两个趋势：1)寻找昂贵的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。由于钛具有单位成本低和生物相容性好的特点，其在口腔修复中的应用越来越广泛。由于钛的活性，熔融的钛与包埋材料发生反应，在铸钛表面形成反应结构，阻碍了钛与陶瓷的牢固结合。完全移除这种结构将牺牲铸件的精确适合性，这在临床上是不可接受的。本研究的长期目标是改善铸造钛-陶瓷的结合，并了解钛-陶瓷的结合机制。其目的是通过最大限度地减少铸钛表面反应结构的形成来改善钛-陶瓷结合，并确定各种因素是如何促成钛-陶瓷结合的。这项研究的中心假设是，通过最大限度地减少铸钛表面反应结构的形成，铸钛与陶瓷的附着力将得到显著改善。这一假设是基于支持性初步研究的结果而提出的。这项研究的基本原理是，表面反应结构可以通过表面涂层图案来最小化，在接近钛凝固的温度下，氧化物比钛氧化物更稳定。我们期望通过追求以下三个具体目标来检验中心假设并实现本应用的目标：1)确定能够改善铸造钛-陶瓷结合的最有效的表面涂层氧化物；2)表征由氧化物表面涂层图案在模拟陶瓷烧成循环前后制备的铸造CP钛表面；以及3)表征钛-陶瓷界面。我们期望通过这项研究能够改善钛-陶瓷的结合性能。研究结果将对钛-陶瓷结合的基本机理提供重要的见解，并将用于未来钛铸造技术和改进的钛-陶瓷系统的发展。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，从而造福于普通公众。

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.