See the amalgam used in the film, then there is a problem of filling teeth. First, you get to the bottom of the dentin, and then the amalgam needs to be flat and straight. In addition, the amalgam is not sticky and is retained by the prepared holes. At present, resin photocuring is widely used without grinding too many teeth. Through pasting and makeup, DMG calcium hydroxide can be used as the bottom layer, and the effect is very good. The bottom of the cavity can be coated with fluoride protectant to seal the dentinal tubule. Can effectively reduce dentin hypersensitivity.