Root canal treatment (also referred to as root canal therapy or endodontic therapy) is a procedure in which the the nerve canals of a tooth are cleaned, shaped, and filled.
Root canal therapy may be warranted due to several different causes including:
deep crack/fracture involving the nerve
irreversible inflammation of the nerve
Symptoms that the pulp has become infected may include sensitivity to hot/cold or sweets, swelling, pain to biting or pressure, and a bad taste in the mouth.
A deep crack in the tooth will cause considerable pain when eating that may not be resolved by a filling or crown alone. Removal of the crack and subsequent root canal can relieve the symptoms.
Sometimes, however, no symptoms are apparent and the person is unaware of any problem until a checkup.
Usually a core build-up and crown is recommended for restoring a tooth that has had root canal therapy.