Inside each tooth is a pulp chamber that contains the nerves and blood supply for the tooth. When the pulp becomes infected due to decay or injury to the tooth, the pulp must be removed from the center of the tooth and the canals of each root. Once the infected pulp is removed, the remaining chamber is filled with a rubber-based material to seal it off.
All teeth that have had root canal therapy must be protected with a tooth-like artificial covering known as a crown. This is because teeth that have had the pulp removed are more susceptible to fracture.
Root canal therapy is an excellent way to save a tooth that would otherwise die and need to be removed.