The crown of the tooth is made up of the hard, white, enamel layer and a thicker dentine layer. Both these hard layers protect the innermost soft tissues of the tooth called the pulp. The dental pulp contains blood vessels and nerves within and extends from the crown to the tips of the root or roots.
Root canal treatment involves the removal of the pulp tissues from the tooth in the event that it gets infected or inflamed. The pulp can be infected or inflamed due to either deep decay or an extensive restoration that involves the pulp, cracked or fractured tooth due to trauma, excessive wear of enamel and dentine exposing the pulp, and sometimes as a result of severe gum disease.
Signs of pulp damage may include pain, prolonged sensitivity to heat or cold, discoloration of the tooth, swelling, tenderness of the overlying gums or a bad taste in the mouth. On the other hand, there may be no symptoms at all. If pulp inflammation or infection is left untreated, it can eventually cause pain, swelling and loss of the supporting bone.