Only the root of the tooth is left, if it can be preserved, root canal treatment, crown restoration, etc. If it cannot be preserved, it will be extracted and restored. 1. In general, if the residual root is not more than 3mm below the gum, the root has enough length, and there is no resorption of the alveolar bone, the doctor usually suggests to retain the root. The retention and treatment of the stump need to be preceded by perfect root canal treatment to eliminate infection, so that the root can be utilized for crown restoration at a later stage. If the stump is long, it can be staked for a crown. If necessary, crown lengthening, orthodontic traction, etc. can be performed to lengthen the portion of the root that is exposed to the oral cavity. 2. If the residual root has no preservation value and cannot be utilized for treatment, then the residual root needs to be extracted as soon as possible and then restored. It is recommended to visit the hospital in time for treatment under the guidance of a professional doctor.