When a tooth becomes infected by a cavity or a crack that extends to the pulp, or nerve, of the tooth, then a root canal is needed. Without treatment, a situation like this can cause the surrounding bone and tissue to become infected, creating an abscess. Root canal treatments have a reputation of being painful, however, with today’s technology and anesthetics, root canal treatments are no more painful than having a dental filling or crown placed. Once a root canal is performed, ti will be necessary to protect the tooth, usually with a dental crown.