The nerve and blood supply that reside within the tooth may be irreversibly affected by stimuli such as deep decay or trauma.
This leads to an infection within the tooth which is often very painful.
In order to save the tooth, a root canal treatment is preformed.
It is a painless procedure where the damaged nerve and blood supply are removed from inside the tooth, the canal system is cleaned thoroughly and filled with special materials. In effect, the tooth is non-vital but still functional.
This treatment usually happens over 2-4 visits.