Tooth hurts when biting down: causes and what to do

What’s probably going on

Sharp pain when you bite down usually has a cause a dentist needs to find. Root canal specialists link it to decay, a loose filling, or a crack. How and when it hurts gives useful clues.

• A cracked tooth. Pain comes and goes as you chew, sometimes as you let go of the bite. Chewing can move the cracked pieces and irritate the nerve inside. The pain can be hard to pin to one tooth, even for your dentist. See cracked tooth.
• A new filling that sits a little high. If the pain started after a recent filling and hurts when your teeth meet, the filling may be getting in the way of your bite. Some sensitivity and sore gums for a week or two after a filling is normal.
• Decay or a loose filling. A cavity can make a tooth hurt when you bite on it. So can a filling that has come loose.
• Inflammation around the root. A badly inflamed or infected nerve can spread trouble past the root tip, into the tissue that holds the tooth in place. Then the tooth hurts when you bite or tap on it. An abscess adds pain that starts on its own, extreme tenderness and swelling. See tooth abscess.
• Grinding or clenching. Grinding can cause a dull ache in your upper teeth and jaw, and over time it can crack teeth. See grinding.
• Your sinuses. A sinus headache can also be felt in your face and teeth, usually as a dull ache and pressure in the upper teeth and jaw.

Pain on biting that also lingers after hot or cold is more urgent. Lingering pain of 30 seconds or more can mean the nerve is damaged for good.

What to do tonight

The goal tonight is to keep the tooth comfortable and stop the problem getting worse.

1. Chew on the other side. Stick to softer food until a dentist has looked at it.
2. Don’t keep testing it. Biting down to check whether it still hurts can move a crack and irritate the nerve further.
3. Rinse with warm salt water. Swish and spit to keep the area clean.
4. Put a cold pack on your cheek. It can help keep swelling down.
5. Take an over-the-counter pain reliever as the label directs. Anti-inflammatories such as ibuprofen can ease pain and swelling. Ask a pharmacist first if you take other medicines, are pregnant, or have stomach, kidney or bleeding problems.
6. Cover a lost filling. A temporary filling from the pharmacy can protect the spot overnight. It isn’t made for a broken tooth. See lost a filling.

For more on getting through the night, see what to do for a toothache right now.

What not to do

• Don’t chew ice, hard candy or popcorn on that side. Hard foods can crack teeth.
• Don’t just live with a high filling. Call the dentist who placed it; they can reshape it.
• Don’t put aspirin on the tooth or gum. It burns the tissue.

How a dentist fixes it, and what it costs

Your dentist will look at the tooth, check your bite, and take X-rays. They may have you bite on a small stick to find a crack. A staining dye can make a crack easier to see.

• A high filling is reshaped so it no longer hits first when you bite.
• Decay or a loose filling is cleaned out and refilled.
• A cracked tooth can’t heal on its own. Depending on how deep it goes, it may need bonding, a crown, a root canal and crown, or removal. A crack that reaches below the gum line usually means the tooth can’t be saved, so early diagnosis matters.
• Inflammation or infection around the root usually needs a root canal, or the tooth taken out.
• Grinding is usually managed with a night guard, plus repairing any damage.
• Sinus pain is treated as a sinus problem. If the tooth still hurts, go back to your dentist.

Cracks and decay caught early usually need simpler treatment. The price depends on the treatment, the tooth, where you live and your coverage, so ask for a written estimate before any work starts.

If you don’t have dental insurance, a dental savings plan (a discount membership, not insurance) can cut the price at participating dentists.

How to keep it from coming back

Most cracks and bite problems build slowly. A few habits help.

• Don’t chew on hard things: ice, popcorn kernels, hard candy, pens.
• If you clench or grind, ask your dentist about a night guard.
• Wear a mouthguard for contact sports.
• Brush twice a day and floss once a day, so decay doesn’t weaken the tooth.
• Get routine checkups, so small cracks and cavities are caught early.
• After a new filling, call your dentist if it hurts to bite or your bite feels off.

A good electric toothbrush makes daily cleaning easier. See the best electric toothbrush.