Root Canal Treatment: Does It Hurt, and When Do You Need One?

What is a root canal, and why does a tooth need one?

Inside every tooth is living tissue called the pulp, which contains nerves and blood vessels and runs through canals inside the roots. Deep decay, a crack or knock to the tooth, or repeated large fillings can leave the pulp inflamed or infected.

This inflammation usually does not heal on its own and can spread to the bone around the root tip, forming an abscess. Root canal treatment removes the source of the problem and keeps the tooth in place so it can keep working for chewing.

What signs suggest you may need a root canal?

These signs do not always mean you need root canal treatment, but they do need checking:

• Sensitivity to cold or heat that lingers after the trigger is gone, rather than fading within seconds.
• Throbbing pain that comes on by itself or wakes you at night.
• Pain when biting or pressing on the tooth.
• Swelling of the gum or face, or a small pimple-like bump on the gum near the tooth.
• A tooth turning darker, especially after an old injury.
• Sometimes there are no symptoms, and the problem is found on an X-ray during a routine check-up.

Does a root canal hurt? What are the steps?

The severe pain many people link with root canals usually comes from the inflammation before treatment. During the visit the tooth is well numbed with local anaesthetic, and most people feel only pressure and vibration. A very inflamed tooth may need extra anaesthetic, which the dentist can give.

Treatment is usually done in one or two visits, depending on the tooth and the degree of infection:

• Examination and an X-ray to see the shape of the roots and the extent of the inflammation.
• Local anaesthetic, then isolating the tooth with a rubber dam that keeps it free of saliva and stops you swallowing any fluids.
• Making a small opening in the tooth, removing the inflamed pulp, and cleaning, shaping and disinfecting the canals.
• Filling the canals with a special rubber-like material and sealing them well.
• Placing a temporary or permanent filling, then planning the final restoration.

Why is a crown often recommended afterwards?

A tooth that needs a root canal has often already lost much of its structure to decay and earlier fillings, making it more likely to crack, especially back teeth that take the force of chewing. That is why a crown is usually recommended to cover and protect it.

Front teeth with plenty of healthy structure left may only need a tooth-coloured filling. Until the final restoration is placed, avoid heavy chewing on the treated tooth, and do not delay the crown too long, as a temporary filling can leak or the tooth can break.

Common myths about root canal treatment

Outdated ideas about root canals lead some people to delay treatment until the problem becomes more complicated:

• "Extraction is better and easier": keeping your natural tooth is usually the better option when possible, as replacing an extracted tooth needs an implant or bridge.
• "Root canals cause illness elsewhere in the body": this is an old theory that modern research has not supported.
• "A dead tooth can never hurt": the tissues around the root stay sensitive, and pain can return if infection does.
• "Antibiotics are enough instead of treatment": antibiotics do not reach inside the tooth or remove the source of infection; they are used only when needed and on a dentist's prescription.
• "Treated teeth do not last": a well-treated tooth restored with a crown can last many years with good care.