The tooth will hurt for about 2~5 days after the nerve is burned. 1. Nerve burning is the basic step of root canal treatment, which usually involves opening the pulp under local anesthesia and placing a pulp inactivating agent in the pulp chamber to achieve pulp nerve inactivation. Pulpotomizing requires the use of a dental drill to create a hole in the tooth for the medication to be placed. This process is relatively painful and the pain lasts for about 2 to 5 days. 2. The duration of pain after nerve burning is related to the individual’s tolerance and the degree of damage to the tooth. Usually, if the individual’s tolerance is high and the degree of tooth damage is light, the pain will gradually decrease in about 2-3 days; if the individual’s tolerance is poor and the degree of tooth damage is high, the pain lasts for a longer period of time, ranging from about 3-5 days. If the pain lasts for a long time after the tooth burns the nerve, and there is no weakening trend, you should go to the hospital in time for follow-up, to clarify the cause of the disease, and carry out targeted treatment as soon as possible, in order to prevent the disease from being delayed and causing other oral problems.