Endodontics can’t be filled directly, but it can be filled after treatment. Because endodontics is a disease that occurs in the pulp of the tooth, the pulp has been infected by bacteria, the nerve has a characteristic that once infected by bacteria is irreversible, the nerve does not have the ability to repair itself, so endodontics should be treated effectively, such as root canal treatment, root canal treatment is completed, the infection is effectively controlled, and then fillings can be made. In order to prevent the tooth from splitting after the filling, it is recommended to make a porcelain crown or an all-porcelain crown for the root canal treated tooth to prevent the tooth from splitting and to prolong the tooth’s service life and lifespan in the oral cavity. However, some patients do not want to make crowns directly after root canal treatment, they can choose to make inlays, inlays are whole materials, bonded to the tooth, the wear and tear on the tooth is not particularly large, but also to meet the aesthetic and chewing function.