The root canal treatment is divided into 3 steps: 1. remove the infected tooth tissue on the tooth surface under local anesthesia, open the pulp cavity and seal in the pulp cavity with drugs for nerve inactivation. 2. remove the infected tooth bone in the pulp cavity, prepare the root canal with mechanical nickel-titanium instruments, and seal in the root canal with calcium hydroxide type anti-inflammatory drugs. 3. use dental cement tip and root filling paste, and fill the root canal tightly with hot dental cement The root canals were filled tightly by vertical pressure filling. After root canal treatment, the tooth usually has a large crown defect, which can be restored with ceramic-type inlays. Fibrous pile resin core all-ceramic or porcelain crowns are used to repair the defect in order to prevent the tooth from fracturing when biting on hard objects due to the brittle nature of the tooth. If the pain of the exposed nerve is particularly severe, you can take oxymorphone tablets or ibuprofen to relieve the pain, as well as cephalexin and metronidazole tablets to reduce inflammation.