Killing the nerve of the tooth, i.e. root canal therapy, is a whole course of treatment including pulp deactivation, root canal preparation, and root canal filling, and cannot be carried out as a single treatment. The overall treatment cost is about 500 to 3,000 RMB, and if crown restoration is needed, the cost of crown restoration will also be increased. Root canal treatment is currently the most effective and commonly used method of treating endodontitis and periapical disease, specifically including the use of special instruments and methods for cleaning and shaping the root canal, the use of medication to disinfect and sterilize the root canal, followed by tightly filling the root canal with root filling material and crown restoration. To control infection, repair defects, and treat or prevent periapical lesions. It is recommended to visit a regular medical institution to receive professional treatment with the help of a doctor.