The tooth is not a solid object, but rather has a space in its center. Each tooth has a soft tissue (the pulp) in this space. This tissue partially nourishes the tooth from the inside. Because of deep decay, injury, or gum disease, the tissue in your tooth has become inflammed or infected (diseased). In any other part of your body, if a similar tissue becomes diseased, the body merely throws it off and forms new tissue. However, a tooth is a uniqueand different situation. Because the soft tissue within the tooth is totally encased within hard tissue, the body cannot get to it in order to affect repair. Therefore, it is the role of the dentist to do what the body is unable to do. He must remove the soft tissue located in the internal spaces(canals), cleanse the area, and finally fill the canals with a special material so that bacteria cannot re-enter the tooth to cause another infection. When the endodontic treatment is complete, the tooth is by no means "dead". It receives quite adequate support from the surrounding tissues and may be expected to last as long as any other natural tooth.