Whether or not root canal treatment hurts the second time is mainly related to the specific condition. If the nerve of the tooth has been cleaned out in the first root canal treatment, it will not hurt, and if the first root canal treatment fails, it may be painful. 1. The second root canal does not hurt: Root canal treatment is a technique that eliminates pulpal infection and cleans and shapes the root canals, then sterilizes and fills the canals with medication to prevent re-infection. The nerve is killed and cleaned out during the root canal treatment, so as long as the nerve is cleaned out for the first time, there will be no obvious pain during the second root canal treatment. 2. Second root canal treatment pain: If there is still pulp left after the first root canal treatment, then the second root canal treatment will also be painful, in this case, you can be treated again under local anesthesia. If the pain is obvious, you can take metronidazole tablets, ornidazole tablets, tinidazole tablets and other antibiotics against anaerobic bacteria according to the doctor’s instruction after the operation to relieve the discomfort. It is recommended that after root canal treatment, regular review should be conducted according to the doctor’s instructions to avoid accidents, and the use of medication should also follow the doctor’s instructions, do not self-medication.