Tooth decay is the result of bacteria that has worked its way under the enamel of a tooth. When decay is left untreated, it will continue to destroy tooth structure and eventually reach the the central pulp chamber where the nerve and blood supply to the tooth are located. Once the pulp has become infected with this bacteria, a toothache and sometimes an abscess ensue. In order to save the tooth from being pulled, endodontic therapy (root canal) must now be performed to remove all the bacteria and infected tissue, and refill the now empty pulp chamber with a biocompatible material. Once the root canal has been successfully completed (usually two visits), a final restoration is placed. Thanks to new techniques and materials, we can now perform root canal therapy more quickly and more comfortably than ever and patients are usually out of pain after the first visit. The best way to avoid root canal is regular check ups to detect and treat cavities when they are small.