Root canal treatment

Root canal treatment removes infected or dead tissue from inside a tooth, cleans and shapes the canals, and seals them so the tooth can be kept rather than extracted. It is done under local anaesthetic, usually in one or two visits, and the tooth is then protected with a filling or crown.

When it is needed

A deep cavity, a crack or a knock can let bacteria reach the nerve. The signs are a lingering ache, pain on biting, sensitivity to heat that lasts, swelling, or a tooth that has darkened. Sometimes there are no symptoms and the problem shows only on an X-ray.

What happens

The tooth is numbed and isolated. The canals are located, cleaned with fine instruments and disinfected, then filled. Where the infection is controlled and the anatomy allows, this is completed in a single visit; otherwise a medicament is placed and the tooth sealed between visits. A back tooth usually needs a crown afterwards, because a root-treated tooth is more brittle.

Retreatment

A tooth that was root-treated years ago can become infected again. Retreatment removes the old filling and repeats the process; in some cases a small surgical procedure at the root tip is the better route. The page on a root canal that did not settle explains how that decision is made.

Alternatives

Extraction, followed by an implant, bridge or denture, or by nothing. Keeping a natural tooth is usually preferred where it can be restored soundly.

Cost

Varies with the tooth (front teeth have fewer canals than molars), whether it is a retreatment, and the final restoration. Your written estimate follows the assessment.