If the cavity is shallow, there is usually no obvious pain; if the cavity is deep, anesthesia is required and no obvious pain will occur. Dental fillings are a common clinical treatment for dental defects caused by caries, trauma and other diseases. According to the depth of the cavity, the pain is also different: 1. Shallow cavity: If the defect is limited to the enamel, there is generally no obvious self-conscious symptoms, and there is no obvious reaction to the doctor’s probing. At this time the filling is generally no obvious feeling, there will be no pain. 2. Deeper cavities: If the defect has reached the superficial or deep dentin layer, the patient is generally sensitive to external stimuli, pain symptoms. At this time, the filling will be painful, so the filling needs to be anesthetized before playing anesthesia, after playing anesthesia and then filling will not appear obvious pain.