What is a Root Canal? A root canal is a treatment used to repair and save a tooth that is badly decayed or becomes infected. During a root canal procedure, the nerve and pulp are removed and the inside of the tooth is cleaned and sealed. Without treatment, the tissue surrounding the tooth will become infected and abscesses may form. "Root canal" is the term used to describe the natural cavity within the center of the tooth. The pulp or pulp chamber is the soft area within the root canal. The tooth's nerve lies within the root canal. A tooth's nerve is not vitally important to a tooth's health and function after the tooth has emerged through the gums. Its only function is sensory -- to provide the sensation of hot or cold. The presence or absence of a nerve will not affect the day-to-day functioning of the tooth. Why Does Tooth Pulp Need to Be Removed? When a tooth's nerve tissue or pulp is damaged, it breaks down and bacteria begin to multiply within the pulp chamber. The bacteria and other decayed debris can cause an infection or abscessed tooth. An abscess is a pus-filled pocket that forms at the end of the roots of the tooth. An abscess occurs when the infection spreads all the way past the ends of the roots of the tooth. In addition to an abscess, an infection in the root canal of a tooth can cause: Swelling that may spread to other areas of the face, neck, or head Bone loss around the tip of the root Drainage problems extending outward from the root. A hole can occur through the side of the tooth with drainage into the gums or through the cheek with drainage into the skin.