Inflammation of the root of the tooth after root canal treatment does not necessarily require extraction. At this time, it is necessary to consult a doctor to check whether the affected tooth has preservation value; if it has preservation value, a second treatment is needed; if it has no preservation value, extraction can be considered. If the first treatment after root canal treatment is incomplete or the crown is not restored in time after the treatment, causing root fracture, etc., it will cause root inflammation, and it is necessary to check whether the affected tooth has retention value or not, as follows: 1. Retention value: if the root inflammation caused by the first root canal treatment is not complete, and the remaining tooth tissue is more, the tooth loosening is not obvious, you can carry out the second endodontic treatment, and timely crown restoration, to retain the affected tooth, rather than extraction. 2. No retention value: If the root is deeply fractured due to the lack of timely crown restoration after root canal treatment, or if there is little remaining tooth tissue and obvious tooth loosening, with a poor long-term prognosis, the tooth can be considered for extraction, after which implant restoration, fixed prosthesis restoration, and removable prosthesis restoration can be chosen at a later stage.