Inlays commonly used materials are the following: 1, alloy inlays: the production of inlays alloy materials such as gold alloy, nickel-chromium alloy, gold alloy chemical stability, casting shrinkage is small, good ductility and mechanical properties, is the production of posterior inlays ideal material; 2, porcelain inlays: the production of porcelain inlays material or method of feldspathic ceramics, lithium di-silicate-enhanced ceramic blocks, as well as computer-assisted design (CAD) with the Computer-aided design (CAD) and computer-aided manufacturing (CAM) inlays, this kind of inlays relative to other inlays, higher precision, better aesthetic performance, better biocompatibility and other advantages; 3, resin inlays: the production of resin inlays is made with a specific method of hard resin in the technical room processed from the elasticity of the modulus of elasticity and dentin similar to the dentin is not easy to fracture, the posterior tooth abrasion is small, broken easy to repair, and polishing is relatively easy.