Dead Tooth / Necrotic Tooth
A dead tooth (also called a necrotic tooth or non-vital tooth) is one in which the tooth pulp no longer has living tissue and there is no longer a blood supply to the tooth. When this happens, the hollow root canal and pulp chamber inside the tooth become a potential site of bacterial colonization, open to the inside of the body.
Frequently, when bacteria find their way into the tooth, and are allowed to multiply unchecked by the body’s immune system, an abscess will result. Often this is accompanied by pain, swelling, and inability to chew on the affected tooth. Sometimes numbness can occur, due to the pressure the infectious fluid places on nearby nerves in the jaw bone.
A dead tooth usually has a history of traumatic injury, extensive tooth decay (caries), periodontal disease, or rapid orthodontic tooth movement. Sometimes, a process called calcific metamorphosis occurs, in which the odontoblast cells that form the dentin layer of the tooth are induced to rapidly deposit large amounts of reparative dentin. The result is a tooth which appears to have no root canal (although it usually continues to have a microscopic one). These teeth may test non-vital, like a dead tooth.