If a tooth hurts after activity, there is a possibility of periodontitis, periapical periodontitis, etc. There are methods such as periodontal treatment and endodontic treatment, as follows: 1. Periodontal treatment: If periodontitis occurs, resulting in loss of periodontal tissue, exposure of the tooth roots, and acute inflammation, resulting in the appearance of complications such as redness and swelling of the gums. In this case, it is recommended to visit the hospital immediately so that the doctor can conduct a specialist examination to determine whether the affected tooth can be retained. If the tooth can still be retained, periodontal treatment can be performed to remove local irritants from the periodontal tissues, and then topical medication can be applied to retain the tooth and continue to perform chewing functions. If the affected tooth is severely loose, the affected tooth needs to be extracted and then set afterwards.2. Endodontic treatment: If it is a case of periapical periodontitis, it is recommended to visit the hospital for endodontic treatment, which is often called root canal treatment, after the treatment is finished, the affected tooth will no longer move and the pain will disappear, so you can continue to exercise your chewing function.