is a clinical diagnostic category indicating death of the dental pulp, necessitating root canal treatment.
The pulp is non-responsive to pulp testing and is asymptomatic. Pulp necrosis by itself does not cause apical periodontitis
(pain to percussion or radiographic evidence of osseous breakdown) unless the canal is infected. Some teeth may be nonresponsive
to pulp testing because of calcification, recent history of trauma, or simply the tooth is just not responding. As
stated previously, this is why all testing must be of a comparative nature (e.g. patient may not respond to thermal testing on
any teeth)