Pulp Necrosis (Dead Tooth Nerve)

• •No response to cold testing on the affected tooth (a healthy tooth feels a brief sharp sensation).
• •Sometimes a noticeable color change — the tooth turns gray, dark yellow, or brown compared to its neighbors.
• •A small bump on the gum near the root tip that comes and goes (a sinus tract draining the infection).
• •Tenderness when biting or when the dentist taps on the tooth.
• •Severe pain in earlier stages, which may then disappear once the pulp has fully died — the tooth is still infected.

Deep cavities that reach the pulp, traumatic injury that severs the blood supply at the root tip (even years earlier), and very deep restorations that overheated or irritated the pulp during placement. Cracks and grinding habits accelerate the process.

Cold testing on multiple teeth establishes the absence of pulp response. The endodontist confirms with electric pulp testing, percussion testing, and a periapical X-ray that often shows a darkened area at the root tip indicating bone loss from infection. J. Morita Veraview X800 CBCT in Endo Mode (per AAE/AAOMR position statement) is used for ambiguous cases.

A necrotic tooth can almost always be saved with root canal therapy, which removes the dead tissue and bacteria, disinfects the canal system, and seals the empty space with gutta-percha. If the tooth is not restorable, extraction followed by an implant or bridge is the alternative. There is no medication or filling that can resurrect dead pulp.