Can docs explain what does the dentist use to numb teeth?

Local Anesthetic: A local anesthetic is used to anesthetize or numb the teeth or area of the mouth where the procedure is to be performed. The anesthetic can be in the form of a topical agent applied to the gums for a less invasive procedure, or a medication that is injected in the mouth. There are a number of different types of local anesthetics with different properties and duration of action.