After root canal treatment, it will be painful when biting something, which may require observation, jaw adjustment, crown restoration or extraction of the affected tooth, etc. It is recommended to go to the hospital for specific examination and treatment. 1. After root canal treatment, there may be root filling paste pressed out of the apical foramen, which will cause pain when biting, generally observe for about half a month and wait for the paste to be absorbed by itself and then recover. 2. After root canal treatment, there is a high point when filling the tooth, and there will be pain when biting, this kind of need to adjust the jaw, and grind the high point to relieve the pain. 3. After root canal treatment, the tooth is easy to split, causing pain, if only part of the fracture, need to do crown repair in time to protect and restore function. 4. If the crown of the tooth is fractured and cannot be retained, the tooth can be extracted.