What Is a Root Canal and How Is It Done?

If your dentist has just said the words "root canal," the appointment that follows is usually more methodical than its reputation suggests. Strip away the folklore and it's a tidy piece of repair work: treat the inside of a troubled tooth so the tooth itself can stay. The short video at the top of this page covers the idea in just over a minute. Its description puts the terminology plainly — "endo" is the Greek word for "inside" and "odont" means "tooth," so endodontic treatment simply means treatment of the tooth's interior, and a root canal is one kind of it. Here's how that treatment unfolds, step by step.

Step one — understanding what's happened inside the tooth

Beneath the hard enamel and dentine sits the pulp: soft tissue containing nerves and blood vessels, running down narrow channels — the root canals — inside each root. When decay runs deep, or a tooth is cracked or injured, bacteria can reach that pulp and leave it inflamed or infected. That's typically when a tooth starts to ache, throb, or react strongly to hot and cold. The aim of the procedure is to deal with that inner problem rather than give up on the tooth altogether.

Step two — numbing, opening, and removing the pulp

Treatment starts with numbing the area around the tooth, in the same spirit as the local anaesthesia described in our guide to anaesthesia and its types. Once you're comfortable, the dentist makes a small opening through the top of the tooth to reach the pulp chamber, then removes the inflamed or infected pulp from the chamber and the canals. This site's second root canal video describes exactly this stage: the pulp comes out, and the inside of the tooth is carefully cleaned and disinfected.

Step three — shaping, filling, and sealing the canals

With the pulp gone, the empty canals are gently shaped and cleaned so they can be filled completely. They're then sealed with a rubber-like material called gutta-percha, which occupies the space where the pulp used to be and helps keep bacteria from getting back in. The tooth still stands and still bites — it has simply lost the living tissue at its centre, which is why treated teeth are checked like any other tooth afterwards.

Step four — restoring the outside of the tooth

Sealing the inside is only half the job. The opening made at the start is closed with a filling, and a tooth that's been weakened by decay or by the treatment itself is often protected with a crown — a cap that restores its shape and strength for chewing. Which finish your tooth needs depends on how much of it remains and where it sits in the mouth, and that's a conversation for your own dentist once they can see the finished result.

MedicalVideos.com has published trusted medical videos since 2007. The site was founded by Dr. Mohamed Ibrahim, MD, PhD — physician and researcher.

Educational only — this article is general information about root canal treatment, not dental advice and not a diagnosis. If you have tooth pain or a damaged tooth, see your own dentist, who can examine the tooth and advise on the right treatment for you.

Frequently Asked Questions

Does a root canal remove the root of the tooth?
No — despite the name, the root itself stays in place. What is removed is the soft pulp tissue from inside the tooth and its root canals. The canals are cleaned, disinfected, and sealed, and the tooth remains anchored by its roots.

Is root canal treatment painful?
The area is numbed first, so the procedure itself is generally comparable to having a filling. Some soreness afterwards is common while the tissues around the tooth settle. Persistent or worsening pain is worth raising with your dentist.

How many appointments does it take?
It varies. Some teeth can be treated in a single visit; others — for example where infection needs to settle, or a crown is planned — take more than one. Your dentist can outline the likely sequence after examining the tooth.

What happens if infected pulp is simply left alone?
An inflamed or infected pulp doesn't reliably heal on its own, and pain or infection can progress, potentially costing the tooth. That's why continuing toothache, swelling, or sensitivity that lingers should be assessed by a dentist rather than waited out.