There are many kinds of posterior inlay materials: 1, gold alloy inlays: including precious metal alloys and non-precious metal alloys; 2, resin materials: resin materials is the use of enhanced composite resin in the model for preparation, preparation of inlays or cutting with CAD/CAM, after the resin bonding material bonded to the tooth; 3, porcelain inlays: porcelain inlays are also divided into porcelain materials, cast porcelain materials have CAD/CAM cutting materials, so now there is a porcelain inlay is closer to the tooth elastic modulus of superior tough porcelain, elastic porcelain, color can achieve good restoration, in the material performance can also do good restoration. CAM cutting materials, now porcelain inlays have been closer to the tooth elastic modulus of superior tough porcelain, elastic porcelain, color can achieve a good restoration, in material performance can also do a good restoration, so now porcelain inlays is a relatively good inlay restoration materials.