At present, the main local anesthetic drugs used in clinical practice for tooth extraction are lidocaine and ativacaine, the duration of anesthesia of lidocaine is about 1.5-2 hours, and that of ativacaine is about 2-3 hours. However, the specific situation depends on the dose of local anesthetic drugs, as well as the patient’s personal constitution and the patient’s sensitivity to local anesthetic drugs. People who usually like to drink alcohol will be less sensitive to local anesthetic drugs, and the metabolism of local anesthetic drugs will be faster, so the duration of anesthesia will be shorter than normal people. Patients with low pain point and fear of anesthesia will have a shorter duration of anesthesia than normal people.