O'Brien W J
School of Dentistry, University of Michigan, Ann Arbor, Michigan, USA.
Compend Contin Educ Dent. 2000 Aug;21(8):625-30; quiz 632.
Dental porcelains have a high glass content, which provides the translucency necessary for esthetic restorations. Because glasses are brittle, they fail under tension or bending by the propagation of preexisting flaws (e.g., scratches, porosities). Several approaches that are based on impeding the propagation of flaws have been used to strengthen dental porcelains, including bonding to metals, adding microcrystalline phases, and surface treatments (i.e., polishing, ion exchange, hydration). Through these methods, porcelain systems are used routinely for all-ceramic anterior restorations; however, porcelain-fused-to-metal restorations remain the most reliable for posterior applications.
牙科陶瓷含有高玻璃成分，这为美观修复提供了必要的透明度。由于玻璃易碎，它们会因预先存在的缺陷（如划痕、孔隙）的扩展而在拉伸或弯曲时失效。几种基于阻碍缺陷扩展的方法已被用于强化牙科陶瓷，包括与金属结合、添加微晶相和表面处理（即抛光、离子交换、水化）。通过这些方法，陶瓷系统通常用于全瓷前牙修复；然而，烤瓷熔附金属修复体在后部应用中仍然是最可靠的。
