With the people appreciate the beautiful increasing,the all ceramic dental restorations, including crowns and bridges, are attractive to dentists and patients because they provide better esthetics, low thermal conductive, abrasion resistance, and biocompatibility as compared with traditional porcelain-fused-to-metal restorations. There are many kinds of ceramic materials in domestic and overseas at present. The technologies of making manufacture and the good and bad of materials function are different. Vita...