Tooth Pain When Biting Down: Causes and What to Do

Your tooth feels fine until you bite down, and then a sharp jolt shoots through it. It is unsettling, and it is one of the most common reasons patients call us.

Pain on biting is a useful clue. It usually means something is wrong with the tooth itself or the tissue around its root, and it rarely clears up on its own. Here is what is usually behind it, what you can do in the meantime, and when to book.

Why does a tooth hurt when you bite down?

Chewing puts pressure on the tooth and on the ligament that cushions its root. If anything in that system is cracked, inflamed, or infected, pressure makes it hurt. The pattern of the pain helps point to the cause.

Common causes of tooth pain when biting down

Cause	What it feels like	Usual treatment
Cracked tooth	Sharp pain on biting, often when you let go	Bonding, crown, or root canal
Deep cavity	Dull ache, sensitivity to sweets or cold	Filling or crown
High or failing filling	One tooth sore after recent dental work	Bite adjustment or replacement
Infected nerve or abscess	Throbbing pain that lingers, sometimes swelling	Root canal or extraction
Gum infection	Tender, swollen gums and a bad taste	Deep cleaning or drainage
Grinding or clenching	Several teeth sore, worse in the morning	Night guard
Sinus pressure	Upper back teeth ache with congestion	Treat the sinus problem

A cracked tooth

Cracks are a classic cause. The pain is often sharp and brief, and it may be worst when you release the bite rather than when you press. Cracks can be hard to spot, even on an x-ray. If you suspect one, read our guide to a cracked tooth emergency. An early crack is far easier to treat than one that has split into the root.

Decay or a filling that needs work

A deep cavity can inflame the nerve, and a filling that sits a little too high can make one tooth take all the force when you chew. Both are straightforward to fix. If a restoration has come loose, see what to do when a crown or filling falls out.

Infection at the root

If the pain throbs, lingers after you stop biting, or comes with swelling or a bad taste, infection is a real possibility. Read about tooth abscess symptoms and treatment. Treatment is often a root canal, which relieves the pain rather than causing it.

Grinding and clenching

If several teeth feel sore and the ache is worst in the morning, you may be grinding in your sleep. That wears on the ligaments around the teeth. See our post on teeth grinding and how it is treated.

Sinus pressure

The roots of your upper back teeth sit right beside the sinuses. During a cold or sinus infection, those teeth can ache when you bite or bend over. If it clears as the congestion does, the tooth was probably innocent.

What you can do before your appointment

• Chew on the opposite side and avoid hard, crunchy, or sticky foods.

• Skip very hot or very cold drinks if they set it off.

• Rinse gently with warm salt water, about half a teaspoon in a glass of water.

• Take an over-the-counter pain reliever such as ibuprofen or acetaminophen, following the label, if it is safe for you.

• Do not keep biting down to test the tooth. It can make a crack worse.

Home care only buys time. It does not fix the cause.

When to see a dentist right away

Call us the same day if you have facial swelling, fever, pus, or pain that is getting worse by the hour. Trouble swallowing or breathing needs the emergency room. For a quick guide to what counts as urgent, see when to go right away for a dental emergency in Toronto. For milder pain, book within a few days. Waiting weeks is how a small crack becomes a lost tooth.

What to expect at the visit

We will ask when the pain happens and what sets it off. Then we test the tooth, usually by tapping on it, having you bite on a small device that isolates one cusp at a time, and taking an x-ray. Cracks sometimes need a second look, so do not be alarmed if the answer is not instant. Once we know the cause, we will explain your options and what each one involves before we start.

Frequently asked questions

Is tooth pain when biting down an emergency?

It is an emergency if you also have swelling, fever, or pus, or if the pain is severe and getting worse. Otherwise it is urgent but not an emergency. Book within a few days.

Can a tooth hurt when biting but look normal?

Yes. Small cracks, early infection at the root, and bite problems often show nothing obvious in the mirror. That is why an exam and x-ray matter.

Will the pain go away on its own?

It may fade for a while, but the cause stays. Cracks spread, decay deepens, and infections grow. Pain that comes and goes still needs to be checked.

How much does it cost to fix?

It depends on the cause. A bite adjustment is a quick, small fix, while a crown or root canal costs more. Coverage under your benefits plan or the Canadian Dental Care Plan may help. We will give you a clear estimate before treatment.

Tooth hurting when you bite down? Schedule an appointment with Lornview Dental. We will find the cause and get you out of pain.