If your tooth hurts when you bite down, the most common causes are a crack in the tooth, a new filling or crown that sits too high, an infection at the tip of the root, a deep gum pocket, grinding or clenching, and, for upper back teeth, sinus pressure. Each one feels a little different, and each one has a different fix. This guide explains the clues you can notice yourself, the simple tests a dentist uses to find the real cause, and when biting pain needs to be seen the same day.
Biting puts force on two things at once: the tooth itself and the thin ligament that holds its root in the bone. Pain on chewing means one of them is irritated. These are the causes dentists find most often:
None of these clues is a diagnosis, but they help you describe the problem clearly when you call, and they hint at what is going on.
| What you notice | Often points to |
|---|---|
| Sharp, brief pain on one spot, sometimes worse when you release the bite; quick twinges with cold | A crack |
| Started within days of a new filling or crown; that tooth seems to touch first when you close | A high filling or crown |
| Dull, steady ache or throbbing; the tooth feels taller; a pimple on the gum or a bad taste | Infection at the root tip |
| Sore, swollen or bleeding gum next to one tooth, often after eating something fibrous | A gum pocket or gum abscess |
| Several teeth tender in the morning, a tired jaw, edges that look flat or worn | Grinding or clenching |
| Several upper back teeth ache together, worse when you bend over, during or after a cold | Sinus pressure |
Two causes can overlap. A tooth that has been cracked for months, for example, can eventually lose its nerve and become infected, so the pattern may change over time.
Finding the cause is mostly a matter of testing one tooth at a time and comparing it with its neighbors. At a toothache visit, Dr. Rana usually combines several of these:
You bite on a small plastic tool placed on one cusp at a time. Pain on a single cusp, particularly the moment you let go, is a classic sign of a crack. Thin marking paper shows whether a recent filling or crown is hitting before the other teeth.
A cold stimulus on the tooth checks the nerve. A quick twinge that fades in a few seconds suggests a living nerve; pain that lingers suggests inflammation; no feeling at all can mean the nerve has died. Gentle tapping and pressing show whether the area around the root is inflamed.
A probe measures the gum pocket around the tooth. A single narrow, deep pocket next to an otherwise healthy tooth can be a sign of a crack running down the root.
X-rays show decay, bone loss and a dark area at the root tip when infection is present. Cracks often don't show on X-rays, which is why the bite and cold tests matter. A digital 3D scan of the teeth can magnify worn spots and visible crack lines, and a CBCT, a 3D X-ray, is sometimes used when a root fracture or a hidden infection is suspected.
Call or text for a same-day appointment if biting pain comes with any of these: swelling of the gum or face, a pimple on the gum, a bad taste that keeps coming back, pain that wakes you up, or a piece of tooth breaking off. Those point to infection or a crack that is getting worse. Our guide to a cracked or chipped tooth explains which breaks can wait a few days.
Go to the ER instead if swelling spreads toward the eye or down the neck, or if you have a fever, trouble breathing or trouble swallowing.
Mild soreness after a new filling isn't an emergency, but don't wait months either. A high spot is usually quick to fix, and leaving it can keep the ligament inflamed. Until you are seen, chew on the other side and skip ice, hard candy and crunchy nuts.
Treatment follows the diagnosis, so two people with the same pain can leave with very different plans:
For a fuller picture of tooth pain in general, see our toothache treatment page. You get your options and their cost in writing before any treatment starts. We accept most major dental insurance, and coverage depends on the plan; we check your benefits for you.
Dr. Aakash Rana, DDS is a general dentist trained at NYU College of Dentistry, with more than $100,000 in continuing education. He plans and treats each case at Prana Dental himself, works with our in-house lab, and refers to a specialist when a case needs one.
Pain only on biting usually means the tooth flexes or the ligament around the root is irritated. A crack, a high filling or early inflammation at the root tip are common reasons. A dentist can sort them out with bite and cold tests.
Pain at the moment you open after biting is a classic sign of a cracked tooth. The pieces flex apart under pressure and snap back when you let go, which irritates the nerve. Unlike a bone, a cracked tooth doesn't knit back together, so it is worth having it checked before the crack grows.
Some sensitivity for a few days after a filling is common. Pain that is clearly on biting, or a tooth that hits first when you close, often means the filling is a little high. Call your dentist, because an adjustment is usually quick.
Yes. The upper back teeth sit right below the sinuses, so sinus pressure can make several of them ache when you chew or bend over. If the teeth test healthy, the pain usually fades as the sinus problem clears.
Not necessarily. Many cases turn out to be a high filling, a crack that needs a crown, a gum problem or grinding. A root canal is usually needed only when the nerve is badly inflamed or infected, which the tests and X-rays help show.
Call or text (786) 579-0521 to tell us which tooth hurts. Same-day appointments run Monday to Saturday, 8am to 8pm.