Porcelain teeth is the best fit, the most realistic color effect of oral restorations. 1950, the United States research with low-fusing porcelain and gold alloys combined into a successful restoration, in 1977, China began to develop non-precious metal and porcelain joint restorations. Porcelain restorations are divided into metal and metal-free porcelain. Metal porcelain refers to the production of metal crowns, as a bracket, in its surface with the natural tooth color similar to the porcelain powder to restore the tooth shape, baked in a vacuum porcelain furnace, so that porcelain and metal alloy fused to form a porcelain crown. The metal crown of metal porcelain teeth has high strength, is the skeleton of porcelain, porcelain has the color and texture of natural teeth. Covering the metal surface with porcelain can make up for the defects of the metal color, fully reflecting the color and shape of natural teeth, and porcelain and gums have better biocompatibility does not cause gingivitis. Precious metal porcelain metal inner crown is generally contains gold, palladium and other precious metals. It has two major advantages: one is the color, especially porcelain teeth and gum contact place is very beautiful, not appear green, gray; second is the porcelain and metal bonding is very good, there are few cases of chipped porcelain, the disadvantage is the higher cost, now, Europe and the United States and other countries mainly apply this technology. Non-precious metal porcelain is generally porcelain on nickel-chromium alloy. Its advantage is the lower cost, the disadvantage is that the edge of the fit is slightly poor, and gingival contact side is easy to appear a green, gray line, slightly affecting the aesthetics, occasionally chipped porcelain phenomenon occurs, at present, China’s main application of non-precious metal porcelain technology. Metal-free porcelain refers to porcelain teeth without metal crowns, is all-ceramic teeth, mainly in the late 80s, in 1996, and the development of successful ultra-porcelain composite fiber bridge technology. Due to the impact of porcelain strength, now mainly used to produce a single porcelain crown or veneer restoration to improve the aesthetics of the front teeth. Such as tetracycline teeth, dead pulp teeth and other discolored teeth beauty, the near future, all-porcelain restoration will gradually replace metal porcelain. Porcelain dental applications: a, after dental treatment restoration: endodontic treatment is easy to cause tooth discoloration, filling loss and tooth fracture, the choice of porcelain full crown restoration can be avoided. Second, set the missing teeth: after tooth extraction, the use of missing teeth before and after the teeth to do retaining teeth, plus missing teeth will be several porcelain crowns together, will be glued to the retaining teeth, you can set the missing teeth. Third, the correction of abnormal tooth development: such as too small teeth, wide gaps, individual teeth are not aligned, enamel underdevelopment, etc., through porcelain restoration can be restored to the ideal tooth shape, color. Fourth, discolored teeth cosmetic: such as tetracycline teeth, fluorosis, dead pulp teeth, etc.