Endodontics is a branch of dentistry recognized by the American Dental Association involving treatment of the pulp and surrounding tissues of a tooth. When you look at your tooth in the mirror, what you see is the crown of your tooth. The rest of the tooth, the part below the gum line, is the root. The outer portion of the root is a hard tissue called dentin. The root canal is the inside that contains a pulp of soft tissue, blood vessels and nerves. Bacteria that are introduced into the pulp, can damage the pulp of the tooth. Root canal therapy involves removing the inflamed and/or infected pulp tissue by a process of cleaning and shaping the root canal. After root canal therapy, the tooth will return to full function.