The posterior alveolar teeth carry out a very important chewing function. If a piece is missing, it is determined by its location and the size of the defect. If the area of the defect is not very large, it is possible to achieve the desired result simply by filling it with resin, which is very fast and can be done in one visit. If the defect is large, the resin filling alone cannot achieve good results, and it is easy to fall off, so inlay treatment is needed. Inlays are divided into resin inlays, metal inlays, and all-ceramic inlays. Onlays require relatively large amounts of tissue to be ground out during the treatment process, but less than full-crown restorations. If the missing area is large, the nerve is involved or the inlay is not well retained, a root canal treatment can be followed by a pile crown or full crown restoration. If the defect is so large that it has reached the subgingival level and cannot be treated well with conventional clinical restorations, it may need to be extracted.