The root canal system

The root canal system contains the dental pulp and extends from the crown of the tooth to the end of the root.  In some cases, a single tooth can have more than one root canal.

The pulp is made up of soft tissue that contains nerves and blood vessels. If the pulp becomes infected by bacteria, it will begin to die. After this, the bacteria can increase in number. The bacteria and the substances they release will eventually pass out of the end of the root canal through the small hole where the blood vessels and nerves enter. 

This process continues as there is nothing to stop more bacteria passing down the root canal, which causes the tissues around the end of the tooth to become red and swollen. This can cause your tooth to become painful and, in extreme circumstances, your face may become swollen (dental abscess).

Outlook

To treat the infection in the root canal, the bacteria need to be removed. This can be achieved by:

---removing the tooth (extraction) 

---attempting to save the tooth by removing the bacteria from the root canal system (root canal treatment)

In root canal treatment, the root canal is cleaned of all bacteria. After the bacteria has been removed, the root canal and pulp are filled and the tooth is sealed with a filling or crown.  In most cases, the inflamed tissue at the end of the tooth will heal naturally.

Root canal treatment should not be painful because local anaesthetic is usually used. The procedure is usually very successful and should be no more unpleasant than having a filling.  In about 9 out of 10 cases, a tooth can survive for up to 10 years after root canal treatment.