What Happens During Root Canal Treatment?

Why it becomes necessary

Inside every tooth is a chamber containing nerve and blood vessels, known as the pulp. Deep decay, a fracture, trauma or repeated dental work can allow bacteria to reach it. Once the pulp becomes irreversibly inflamed or infected, it cannot recover.

At that point there are two realistic options: remove the pulp and keep the tooth, or remove the tooth. Root canal treatment is the first of those.

Signs that are often reported

Symptoms vary and none are diagnostic on their own — some teeth needing treatment cause no pain at all and are found on a radiograph.

• Lingering pain after hot or cold, rather than a brief sharp response
• Spontaneous or night-time pain
• Pain on biting or pressure
• Tenderness or swelling of the gum near the tooth
• A tooth that has darkened compared with its neighbours

The procedure step by step

The tooth is numbed with local anaesthetic and usually isolated with a rubber dam, which keeps the working area dry and free of saliva. An opening is made through the crown of the tooth to reach the pulp chamber.

The canals are then cleaned with fine instruments and irrigating solutions, shaped so they can be sealed, and measured to their full length. Once clean and dry, they are filled with a sealing material and the access opening is closed. Depending on the case this happens in one visit or two, sometimes with a medicated dressing in between.

What it feels like

The procedure itself is performed under anaesthetic and is generally comparable to having a filling placed, though it takes longer. Much of the pain associated with root canals is the pain that precedes them.

Afterwards, tenderness to biting for a few days is common as the surrounding ligament settles. Increasing pain, swelling or fever should be reported promptly.

Restoring the tooth afterwards

A root-treated tooth has lost internal structure and, in back teeth especially, is more prone to fracture. A definitive restoration — often a crown or a cuspal-coverage restoration — is usually recommended, and delaying it is a common reason treated teeth are eventually lost.

Root canal treatment has a well-documented record, but no treatment succeeds universally. Retreatment, surgical approaches or extraction remain possibilities if healing does not occur.