Root canal treatment

Introduction

Root canal treatment is a dental procedure to treat infection at the centre of a tooth (the root canal system). Root canal treatment is also called endodontics. The infection is caused by bacteria that live in the mouth and invade the tooth when:

  • tooth decay occurs
  • fillings leak
  • teeth are damaged by trauma, such as a fall 

See the Health A-Z topic on Tooth decay for more information about how decay starts.

Tooth structure

A tooth is made up of two parts:

  • The crown is the part of the tooth that is visible in the mouth.
  • The root extends into the bone of the jaw, anchoring the tooth in position.

These are composed of the following structures:

  • Enamel is the hard outer coating of a tooth.
  • Dentine is a softer material that supports the enamel and forms most of the tooth. 
  • Cementum is a hard material that coats the root surface.
  • Dental pulp is the soft tissue at the centre of the tooth.

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. A single tooth can have more than one root canal.

The pulp is made up of soft tissue that includes nerves and blood vessels. If bacteria infect the pulp, 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 bacteria are removed from inside the root canal system, the root canal is 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.

Glossary

Abscess
An abscess is a lump containing pus, which is made by the body during infection.

Bacteria
Bacteria are tiny, single-celled organisms that live in the body. Some can cause illness and disease and others are good for you.

Inflammation
Inflammation is the body's response to infection, irritation or injury, which causes redness, swelling, pain and sometimes a feeling of heat in the affected area.

Last updated: 09 July 2012

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