The nerve line of the tooth is correctly referred to as the dental nerve. Under normal circumstances, the tooth will not feel pain after nerve removal, but may still feel pain if the nerve is not cleanly removed or the periapical lesion has not healed, as follows. 1. Will not feel pain: tooth pain sensation by the nerve innervation, the tooth will not feel pain after nerve extraction. 2. May feel pain: (1) Nerve extraction is not clean: the root canal system of the tooth includes some tiny branches, in which there may be nerves distributed, if they are missed when the nerve is extracted, it will cause pain when the subsequent root canal rinsing and disinfection is carried out. (2) Unhealed periapical lesions: After nerve extraction, the inflammation at the periapical tissues has not yet been eliminated, and the exudation of tissue fluid and inflammatory factors caused by the inflammation will still cause pain. If the pain is severe or accompanied by other symptoms, it is recommended to go to the hospital in time.