Tooth exposed nerve is mostly due to tooth decay or trauma caused by pulp exposure, in the external stimuli will cause severe pain, usually need root canal treatment to eliminate pain. 1. When the tooth decay is too deep, or by external impact, crown defects, can cause pulp exposure, the pulp is infected by the outside world, and at the same time in a variety of external stimuli, the tooth will appear severe pain. 2. To solve the pain, it is generally necessary to carry out root canal treatment, remove the pulp, root canal disinfection, root canal filling after no symptoms, and crown restoration is recommended after root canal treatment. Nerve exposure of the tooth is recommended to go to the hospital in time to do oral and X-ray examination, as soon as possible to deal with, to avoid aggravation of the symptoms caused by periapical periodontitis aggravate the pain.