Endodontic — or root canal — treatment is necessary when the pulp, the soft tissue inside the root canal, becomes inflamed or infected. The inflammation or infection can have a variety of causes: deep decay, repeated dental procedures on the tooth, or a crack or chip in the tooth. In addition, an injury to a tooth may cause pulp damage even if the tooth has no visible chips or cracks. If pulp inflammation or infection is left untreated, it can cause pain or lead to an abscess.
Signs to look for include pain, prolonged sensitivity to heat or cold, tenderness to touch and chewing, discoloration of the tooth, and swelling, drainage and tenderness in the lymph nodes as well as nearby bone and gingival tissues. Sometimes, however, there are no symptoms.