Inside the tooth, under the white enamel and the next hard layer called the dentin, is a soft tissue called the pulp. The pulp contains blood vessels, nerves, and connective tissue and helps build the tooth during development. The pulp extends from the crown of the tooth to the tip of the roots through a hollow channel called the root canal, where it connects to the tissues surrounding the root.
Root Canal treatment is necessary when the pulp, becomes inflamed or infected. Inflammation or infection maybe due to a deep cavity, repeated dental procedures on the tooth, or a crack or chip in the tooth. A blunt injury to a tooth may also cause pulp damage even if the tooth has no visible fracture. If pulp inflammation or is left untreated, it can cause throbbing pain or an abscess.
As against popular belief, root canals are not painful. They might need a longer mouth opening than routine fillings and sometimes may need multiple sessions. When root canals are very skinny or curved and difficult to negotiate, referral to an endodontist may be necessary.
A root canal treated tooth, depending on the amount of tooth structure lost, and also since it is more brittle might need a post and a crown placed on it to keep the tooth structure reinforced.