Nerve extraction is known as pulpotomy. If the pulp is removed completely, the pain can usually be eliminated after the operation. If periapical inflammation exists in the affected tooth, the pain will be relieved after 3~5 days by postoperative sealing, but if there is any residual pulp, it can continue to cause pain, as described below. 1. Thorough pulp removal: The pulp tissue, including inflammatory substances and nerves, is completely extracted using a pulpotomizing needle to terminate the pain symptoms of the tooth. 2. Periapical inflammation in the affected tooth: Inflammation in the apical part of the tooth still exists after the pulp is extracted, so it is necessary to seal medicines in the root canal, such as calcium hydroxide, camphor p-chlorophenol, etc., and wait for 5-7 days to control the inflammation in the periapical area, so that the pain symptom can be relieved. 3. Residual pulp: Because there are many small branches in the pulp, the pulp may be missed during extraction, and the residual inflamed pulp will continue to cause pain. If the pain is severe after pulp extraction or accompanied by other symptoms, it is recommended to go to the hospital for early treatment.