Resources · General Dentistry

6 signs you might need a root canal.

By Dr. Tim Rauch, DDS · Hollister, CA

A root canal treats an infected or badly inflamed nerve inside a tooth — usually from deep decay, a crack, or repeated dental work on the same tooth. Here's what tends to show up beforehand.

1. Lingering pain after hot or cold

Sensitivity that fades in a few seconds is normal. Pain that lingers for a minute or more after hot coffee or cold water is a different signal — it often means the nerve itself is irritated or infected, not just the outer tooth surface.

2. Pain when you bite down or chew

Sharp pain specifically when pressure is applied — biting, chewing on that side — can point to inflammation around the root tip, sometimes from a crack that doesn't show up without imaging.

3. A dull ache that won't go away

Not sharp, not triggered by anything specific — just there. A persistent, low-grade ache is easy to ignore for a while, which is exactly why it's worth getting checked before it becomes a sharper problem.

4. Swelling or a small bump on the gum

A small bump near a specific tooth — sometimes called a "gum boil" — can be a sign of an abscess draining. It may not hurt much, which makes it easy to dismiss. It shouldn't be.

5. A tooth that's darkened

A tooth that's turned noticeably darker than the ones next to it can mean the nerve inside has died, even without pain. It's one of the few signs that's purely visual — worth mentioning at your next cleaning even if nothing hurts.

6. Tenderness in the gum or bone around one tooth

Tenderness localized to one specific tooth — not general gum sensitivity — often points to an issue with that tooth's root rather than your gums generally.

What if it's more than one of these?

One sign alone isn't a diagnosis — plenty of these overlap with less serious issues, like a cavity that just needs a filling. But any of them is worth an exam, and digital x-rays settle the question quickly. If it is the nerve, a root canal is a well-understood, routine procedure — done here, in the same office as your regular checkups, with no separate referral for straightforward cases.

Don't wait on a dull ache.

An exam and an x-ray settle the question fast. If it's not the nerve, you'll know that too.