Endodontic therapy or root canal therapy is performed to devitalize or remove the pulp tissue of a tooth. The pulp is the primitive tissue in the very center of every tooth. It is a very simple tissue consisting of a nerve, artery, and vein. It is also a very vulnerable tissue in that it has no ability to heal itself. Once it gets insulted or damaged by trauma, decay, a deep crack or some other injury it will always die and lead to an eventual abscess. Once this happens, the only options are endo therapy or extraction of the tooth. If the dead infected tooth is left untreated, the abscess will always grow slowly destroying bone around the tip of the root and often times spread to neighboring teeth.