You take a bite of toast and, ouch. One tooth sends a sharp little jolt through your jaw, then settles down like nothing happened. So you start chewing on the other side and hope it goes away.
Sound familiar? If your tooth hurts when biting, you're in good company. It's one of the most common reasons people call their dentist. It's also one of the most confusing, because the pain comes and goes, and you often can't tell which tooth it is.
Let's look at what might be going on, what your dentist will check, how to manage in the meantime, and when to stop waiting.
Why does biting make a tooth hurt?
Your teeth aren't glued solidly into your jaw. Each one sits on a thin layer of fibres called the periodontal ligament, a tiny shock absorber packed with nerve endings that sense how hard you're biting. If it gets irritated, say from an infection, grinding or one tooth taking too much of the load, even soft food can feel bruising or sharp.
Or the trouble could be inside the tooth, in the pulp, the soft centre where the nerve lives. If a crack or deep decay irritates it, the tooth can complain every time you chew.
What could be causing it?
These are the usual suspects.
A cavity
Decay that's eaten through the enamel weakens the tooth from the inside. Bite down and you might be pressing on soft, damaged tooth near the nerve, which gives you that quick zing. Small cavities usually just need a filling; bigger ones might need more work.
A cracked tooth
This one's common, and sneaky. The classic sign is a short, sharp pain when you chew, often worst the moment you let go, as the crack closes back up. A hairline crack often won't show up on an X-ray, either. Back teeth with big fillings are more at risk, and so are people who grind.
Here's the frustrating part: a crack doesn't heal like a broken bone, and it can slowly spread. Depending on how deep it goes, a dental crown can hold the tooth together so it doesn't flex every time you bite. If the crack has reached the nerve, that may need sorting first.
An irritated or infected nerve
Once the nerve inside the tooth is inflamed or infected (usually after deep decay, a crack or an old knock), the problem can spread to the area around the root tip. That makes the tooth really tender to press on, and it might even feel a little “taller” than the teeth beside it. You might also notice a throbbing ache, hot drinks that hurt for a while afterwards, a swollen gum or a nasty taste. In many cases, root canal treatment can clear the infection out from inside the tooth, which often means you get to keep it.
A filling that's too high, loose or worn
Had a filling or crown done recently? If it's sitting a fraction too high, that tooth hits first every time you close and takes the whole force of your bite. Luckily, that's a quick fix: your dentist just smooths it down. Older fillings can also loosen or leak, letting bacteria sneak underneath.
Grinding and clenching
Lots of people grind or clench without knowing it, usually in their sleep or when stressed. All that pressure can leave several teeth feeling bruised and your jaw stiff in the morning, and over time it can wear teeth down or crack them. A custom-fitted night guard can take the brunt of it while you sleep.
Your gums
Sometimes the tooth itself is fine and the gum is the problem. Food jammed between teeth, a gum infection, gum disease or an inflamed flap of gum over a wisdom tooth can all make a tooth sore to chew on or slightly loose.
Your sinuses
This one surprises people. The roots of your upper back teeth sit right under your sinuses. When you've got a cold, hay fever or a sinus infection, the pressure can make several top teeth ache when you bite or bend over. If it clears up when your nose does, your sinuses were probably behind it.
What happens when you see the dentist?
Your dentist will start with a few questions, like when it started and what sets it off. Then they'll look at the tooth and gums and check how your teeth meet. They might ask you to bite on a small tool one spot at a time to find exactly where it hurts. A cold test shows how the nerve is doing, and X-rays can pick up decay or infection you can't see.
Fine cracks don't always show up, so it can take more than one visit to be sure.
How is each cause usually treated?
What helps depends on what's behind the pain, but here's roughly what to expect.
| If it's… | What usually helps |
|---|---|
| A cavity | A filling, or more involved treatment if the decay runs deep |
| A cracked tooth | Often a crown to hold it together, with root canal treatment first if the crack has reached the nerve |
| An infected nerve | Root canal treatment to clear the infection and keep the tooth |
| A filling sitting too high | A quick adjustment to smooth it down |
| An old or leaking filling | Replacing the filling |
| Grinding or clenching | A custom-fitted night guard to wear while you sleep |
| A gum problem | Clearing trapped food, a professional clean or gum treatment |
| Sinus pressure | Usually settles as your sinuses clear; see your GP if it lingers |
If a tooth can't be saved, Acme Dental dentist will talk you through removing it and the options for filling the gap.
How can you ease the pain until then?
- Chew on the other side and go for softer foods.
- Skip anything really hard or sticky (ice, nuts, hard lollies) and anything very hot, cold or sugary if it sets the pain off.
- Over-the-counter pain relief may help. Follow the label, and check with your pharmacist if you take other medicines.
- Rinse gently with warm salty water to keep the area clean.
Painkillers only take the edge off, though. A crack or infection can keep getting worse in the background.
When should you get help quickly?
Book in with your dentist if the pain lasts more than a couple of days, keeps coming back or doesn't settle with pain relief.
Get in touch as soon as you can about an emergency dental appointment if you have:
- swelling in your gum, face or jaw
- a fever, or you feel unwell, along with the tooth pain
- severe, throbbing pain that's keeping you up at night
- a broken or injured tooth
Call 111 or head to your nearest emergency department if the swelling is spreading towards your eye or neck, or you're struggling to breathe, swallow or open your mouth.
If it started after an accident, like a fall or a sports knock, ACC may help with treatment costs.
Frequently asked questions
Will a tooth that hurts when biting get better on its own?
Sometimes. If it's from a sinus infection or a short spell of clenching, it can settle by itself. Cracks, decay and infections won't. They need treatment and usually get worse.
Why does it only hurt when I let go of a bite?
That's a well-known sign of a cracked tooth. Biting pushes the crack open a tiny bit, and when you let go it snaps shut, which irritates the nerve. Other problems can feel similar, so best to get it checked.
Is it normal for a tooth to be sore after a filling?
A bit of tenderness for a few days can be normal, especially after a deep filling. But if biting feels sharp, or that tooth seems to hit first when you close, the filling might need a small tweak. Call your dentist rather than putting up with it.
Does pain when chewing mean I need a root canal?
Not necessarily. Plenty of causes are sorted with a quick bite adjustment, a new filling, a crown or help with grinding. Root canal treatment usually only comes into it when the nerve is badly inflamed or infected, and your dentist checks that with tests and X-rays.
Getting a sore tooth checked in Devonport
A tooth that hurts when you bite is usually trying to tell you something, whether that's a crack, a cavity, an unhappy nerve or a bite that's slightly off. Most are easier to fix when caught early, and regular check-ups and preventive care can spot worn fillings and small cracks before they start to hurt.
If a tooth is bothering you when you chew, come and see the team at Acme Dental in Devonport. We'll find out what's going on and talk you through your options. Call 09 243 1500 or book online.