Root canals have a reputation of being quite painful. They're actually not that bad. Teeth are tough on the outside, but inside they have a soft core called a nerve chamber. This core is made up of tissue and blood vessels that feed the nerve. Serious irritation of the nerve can be caused by deep decay, or perhaps having a deep filling as a result of that decay, or an injury to the tooth. If a nerve degenerates completely, the tissues die and gangrene develops. The nerve chamber may also become infected in some cases. This dead nerve usually leads to infection, resulting in pain and swelling.

When these chambers, or “canals” become infected, the dentist will drill the tooth, clean the canals, and fill them with a flexible plastic material. Crowns are then added to strengthen the tooth. The procedure itself takes one to two visits, and you will likely be sore for two or three days.