Endodontics deals with the tooth pulp inside the tooth and the tissues surrounding the root of a tooth. If the pulp becomes diseased or injured, endodontic treatment — a root canal — is required to save the tooth. When the nerve inside the tooth is damaged it can be very painful and as the decay continues to spread, the nerve will die. With a root canal procedure, this damaged tissue is removed and replaced with dental filling. Although it may sound frightening, a root canal is generally a simple one- or two-visit procedure that allows you to retain a tooth that in previous decades the dentist would have removed.