When the tooth is rotten and only the root is left in the flesh, the treatment needs to be based on the specific situation of the root, such as the depth, as well as the degree of stability, such as whether there is obvious looseness, etc., and the choice of filling, crown restoration and implantation after extraction and other treatment programs. 1. Depth: If the location of the root is 2mm below the gingiva, the gingival line can be placed to promote gingival recession, after which the surface decay will be removed with a low-speed ball drill, and finally filled with composite resin, glass ionomer cement. If it is more than 2mm, the soft tissue can be removed under local anesthesia, and the cavity can be completely exposed and then filled. 2. Degree of stabilization: (1) Root stability: If there is perforation at the bottom of the pulp chamber through X-ray examination, but the root is relatively stable, the perforation can be repaired by MTA, and then after root canal treatment, crown restoration can be performed. (2) Root loosening: If the patient’s tooth root has been separated and loosening is obvious, the tooth root should be extracted, and then fixed prosthesis restoration or implantation treatment should be carried out. It is recommended to go to the hospital to improve the relevant examination, under the advice of the doctor, choose the appropriate treatment program.