If you have been told that a root canal is necessary to save one of your teeth, it is important that you understand why this procedure is necessary and what happens during root canal treatment. Root canal treatment (endodontics) treats disorders of the nerve (also called the pulp) of the tooth It used to be that a tooth with a diseased or infected nerve in it had to be removed. In 95 percent of the cases today, however, this is no longer true. We believe in saving teeth (instead of removing them). The following are the most common factors contributing to a need for root canal treatment: Traumas, such as a physical blow to a tooth, Physical irritation caused by a deep decay or a very large filling, Severe gum disease. Regardless of the initial cause, the tooth pulp becomes irritated and infected. Bacteria grows within the tooth pulp, causing pressure and if a cavity forms and is allowed to go untreated for too long, it can penetrate to the root pulp where and infection can occur pain, sometimes accompanied by swelling of the face. Sometimes the deterioration of the pulp happens so gradually that little pain is felt. Regardless of the amount of pain felt, eventually the bacteria can destroy the pulp. As this happens, the bone surrounding the tooth may become infected and abscessed, which may lead to the destruction of the bone surrounding the tooth.