Root canal treatment

What is the root canal?

The crown of the tooth is made up of a hard, white enamel layer and a thicker dentine layer. These layers protect the innermost soft tissues of the tooth, called the dental pulp. This pulp contains blood vessels and nerves, and it extends from the crown to the tip of the root, or roots. The pulp of each tooth runs through the centre of the root in small root canals. It is usual for the front teeth to have a single root canal, whilst molars often have three or more canals.

What causes problems in the root canal?

The pulp can become infected or inflamed as a result of:

  • Deep decay
  • Extensive filling or crown of the tooth close to the pulp
  • The tooth suffering cracks or fractures through trauma
  • Excessive wear of the enamel and dentine layers leading to exposure of the pulp
  • Severe gum disease

What are the signs of pulp damage?

Signs may include:

  • Pain
  • Prolonged sensitivity to heat or cold
  • Discolouration of the tooth
  • Swelling
  • Tenderness in the surrounding gums
  • A bad taste in the mouth

In some cases, however, there are no symptoms at all.

Why should I have root canal treatment?

If pulp inflammation or infection is left untreated, it can cause pain, swelling and loss of the supporting bone. Root canal treatment saves teeth that would otherwise have to be extracted. It is always better to retain your natural teeth where possible.

After root canal treatment, the tooth is pulp-less, meaning that it has no vital tissues within. Although the tooth is ‘dead’ the gum and bone supporting it is still alive. A tooth that has been treated can function normally and can be maintained with routine dental care and oral hygiene measures but you will normally be advised to have it crowned.

How is root canal treatment carried out?

Root canal treatment may take a single visit or multiple visits, depending on the complexity of the tooth.

  • The tooth is anaesthetised.
  • The tooth is isolated with a rubber membrane, providing a clean and saliva free environment.
  • An opening is made in the crown of the tooth to allow access to the infected or inflamed pulp.
  • The root canals are cleaned using specially designed hand or rotary files. Debris within the canal is removed by flushing with an anti-bacterial solution
  • Often, X-rays are taken to determine the length of the root and to monitor the various treatment stages.
  • In between treatment appointments, medicaments may be placed within the canals and the tooth covered with a temporary filling.
  • The canals are finally filled or sealed with an inert material called gutta-percha. The tooth is restored to full shape and function by either a permanent filling or a crown, depending on how much of the tooth is left. This should be done as soon as possible as there could be a risk of tooth fracture due to biting forces.

Is root canal treatment painful?

Root canal treatment procedures are relatively comfortable and usually painless, as the tooth is anaesthetised during treatment. After treatment, the tooth may be sensitive or tender for a few days due to the inflammation of the surrounding tissues. This discomfort can be relieved by taking mild analgesics or painkillers available over the counter at the pharmacy. However, if the pain persists and is severe, or a swelling occurs, you should contact your dentist.

Should I treat my tooth differently after root canal treatment?

As far as possible, avoid chewing or biting on the tooth being treated until you have it permanently restored with either a filling or a crown. Excessive pressure at this stage may crack or fracture the tooth. Following permanent restoration, however, most endodontically treated teeth last as long as natural teeth.

Practise good oral hygiene, including brushing and flossing at all times, as root-filled teeth are as prone to decay as natural teeth but you will not get any pain. It is also important to have your treated tooth reviewed regularly by your dentist.


A molar with four root canals before treatment

After treatment, the rotated view clearly shows four canals

This premolar has both apical and lateral radiolucencies

There is a lateral canal and apical bifurcation