How do you know if you need a root canal?

Signs you may need a root canal

The American Association of Endodontists lists severe pain when chewing or biting, pimples on the gums, a chipped or cracked tooth, lingering sensitivity to hot or cold even after the sensation has been removed, swollen or tender gums, and deep decay or darkening of the tooth. Cleveland Clinic gives a similar list: a pimple or boil on the gums that may leak pus, swelling in the jaw from a trapped infection, tenderness or swelling in the gums, pain when chewing or pressing on the tooth, pain that spreads to the jaw, face or nearby teeth, and a lingering toothache or pain from hot or cold drinks. Having one sign does not mean you need a root canal. Several of these also appear with other tooth and gum problems, which is why an examination matters.

What does a tooth that needs a root canal look like?

Cleveland Clinic says the tooth may look darker than the teeth around it and may feel loose, because an infection can weaken the bone that holds it. The American Association of Endodontists also lists darkening and deep decay, and a chipped or cracked tooth. A gum pimple near the tooth is another visible sign. Some teeth that need treatment look normal from the outside, so what you can see in a mirror is not a reliable test.

What does it feel like?

Cleveland Clinic describes throbbing or ongoing pain, pain or sensitivity when you bite down on or touch the tooth, and discomfort with temperature changes. Healthline's page on tooth pain when you bite down says early damage to the pulp may make a tooth sensitive to heat, cold and very sweet foods, and that a pain that lingers and gets worse with gum swelling may point to an abscess. Pain that spreads is possible: Cleveland Clinic's abscess page says severe tooth pain may seem to spread to the ear, jaw or neck.

Can you need a root canal without pain?

The sources we read do not state this outright. The American Association of Endodontists list includes signs that are not pain, such as pimples on the gums, a chipped tooth and darkening. Cleveland Clinic's abscess page says pain can ease when an infection kills the pulp, because the nerves stop working, but the bacteria keep spreading and damaging surrounding tissue, so you should still see a dentist when the pain goes away. A tooth that stops hurting is not necessarily a tooth that has healed.

How is the need confirmed?

The American Association of Endodontists says the endodontist examines the tooth and takes X-rays before treatment begins. Cleveland Clinic says a dentist or endodontist can help determine whether a root canal is right for you, and does not describe the tests in detail. Expect questions about when the pain started, what triggers it and whether anything makes it better or worse. Your dentist may also test how the tooth responds to temperature and pressure, though the sources we read do not list the tests, so we leave that for your dentist to explain. Sometimes the answer is a filling, a crown or extraction instead.

How do you know if a root canal is failing?

Cleveland Clinic says pain that keeps throbbing after treatment may mean infected pulp remains, and that pain or sensitivity lasting longer than about a week should prompt a call. If the damage was too severe, you might need a second root canal or removal of the tooth, replaced with an implant or bridge. Swelling or pain that does not improve is also a reason to call. Mild soreness and some lingering sensitivity are normal.

Is pain after a root canal normal?

Mild pain is common. The American Association of Endodontists says mild soreness or tenderness for a few days is typical, that sensitivity when biting is common during healing, and that symptoms usually improve within three to five days. Over-the-counter pain relievers often help and a cold compress on the outside of the cheek can ease swelling. It advises contacting your endodontist for severe or worsening pain, significant pressure, or pain lasting more than a few days. Cleveland Clinic gives about a week. The two timelines differ, so if you are unsure, call your dentist sooner rather than later. See our guide on whether a root canal is painless.

What happens if you wait?

Cleveland Clinic says the sooner an abscess is treated, the less likely the infection is to spread, and the NHS says a dental abscess needs prompt treatment from a dentist and will not clear up on its own. Treatment can involve draining the pus and a root canal or extraction. Healthline notes that untreated infection can spread to nearby tissue and, in rare cases, lead to sepsis. That is why lingering pain, swelling or a gum pimple deserves an appointment, not a wait-and-see approach.

Questions to ask your dentist

Take these to the appointment.

• Do the X-rays show infection, and how sure are you that the pulp is damaged?
• Is a root canal the only option, or could a filling or crown work?
• Should I see an endodontist, and what will they do differently?
• Will I need a crown afterwards, and when?
• What should I expect in the first week, and when should I call?

Frequently asked questions