how long for local anesthesia
The duration of local anesthesia varies with the type of anesthesia given. Typically, the effect lasts from 2-4 hours, but in many people it can last for up to half the day. You may speak to your dentist for the option of having the length of anesthesia increased or decreased by the type of numbing agent they give you. In brief: A few hours. The duration of local anesthesia varies with the type of anesthesia given.