After the x-ray your dentist will administer an anesthetic, numbing the tooth and surrounding tissues. The tooth has to be isolated from moisture with a small protective sheet called a dental dam. It is placed around the tooth and held in place with a bracket. With the tooth numbed, the dentist makes a hole in the crown of the tooth. The infected pulp is removed from the tooth's root using small thin instruments and a space is made in the chamber of the tooth. If the tooth has an abscess the pus will be drained before removing the pulp. When the tooth is clean, the roots are filled with a biocompatible material.