Root canal therapy (also called endodontics) is needed when the blood or nerve supply of the tooth (called the pulp) is infected through decay or injury. You may not feel any pain in the early stages of the infection.

In some cases your tooth could darken in colour, which may mean that the nerve of the tooth has died (or is dying). If the pulp becomes infected, the infection may spread through the root canal system of the tooth. This may eventually lead to an abscess. An abscess is an inflamed area in which pus collects and can cause swelling of the tissues around the tooth. The symptoms of an abscess can range from a dull ache to severe pain, and the tooth may be tender when you bite. If root canal treatment is not done, the infection will spread and the tooth may need to be taken out.

A local anaesthetic is used and it should feel no different to having an ordinary filling done. The aim of the treatment is to remove all the infection from the root canal.

At the first appointment, the infected pulp is removed and any abscesses can be drained. The root canal is then cleaned and shaped ready for the filling. A temporary filling is put in and the tooth is left to settle. There may be some tenderness afterwards. The tooth is checked at a later visit and when all the infection has cleared, the tooth is permanently filled.

You may need to have a crown after root canal therapy has been completed to provide extra support and strength to the tooth.

Root canal treatment is a skilled and time-consuming procedure. Most courses of treatment will require more than 1 visit.