If the tooth still hurts after killing the nerve, if a thorough root canal treatment was done, a CT can be taken to check if there are any remaining root canals that were not treated. In addition, if dry pulp treatment was done, it is possible that the nerve of the tooth has not been completely dried up, in which case a complete root canal treatment is needed. If the nerve killing medication is sealed and the second step of treatment has not been performed, this is a mild pain that will occur for the first three or four days after the medication is sealed and will not be immediately and completely relieved. In addition, if severe pain occurs after the nerve-killing medication has been sealed, you should go to the stomatology department in time to have the sealed medication removed and the nerve opened and soothed, which can provide quick relief. If the pain occurs long after the nerve has been killed, it is recommended to check for tooth splitting or root fracture. If this symptom occurs, the affected tooth should be extracted promptly.