In brief
Pain when biting can come from several different sources: a cavity that has weakened the tooth, a crack that flexes under pressure, a filling or crown sitting slightly too high, inflammation at the root tip, gum infection around the tooth, or even sinus pressure affecting upper back teeth. Because these causes require very different treatments, bite pain is a symptom to investigate rather than self-diagnose — a dental examination with testing and X-rays is how the actual cause is found.
Key takeaways
- Bite pain has multiple possible causes with different treatments.
- A sharp pain on release of biting is a classic sign of a cracked tooth.
- A recently placed filling that hurts on biting may simply need adjustment.
- Constant pressure pain can indicate inflammation at the root tip.
A tooth that hurts when you bite is usually telling you that something is changing under pressure: a crack that flexes, decay that has weakened the tooth, a filling that sits too high, or inflammation around the root. Gum problems and sinus pressure can cause similar pain. Because each cause needs a different treatment, an exam is the only reliable way to find out which one you have.
This guide explains the common causes of pain when biting or chewing, what the type of pain may suggest, how a dentist finds the source, what you can do at home in the meantime, and when bite pain needs urgent attention.
Why does my tooth hurt when I bite down?
When you bite, your teeth take a lot of force. A healthy tooth, supported by healthy gums and bone, handles that force without discomfort. Pain appears when part of that system is damaged or inflamed, so the pressure of biting presses on a sensitive area.
The most common causes are listed below. Some are minor and quick to fix; others need prompt treatment to save the tooth.
What are the common causes of pain when biting?
A cracked tooth. Cracks often cause a sharp, brief pain when biting — classically when releasing the bite — and may be worse with certain foods or angles. Cracks can be invisible on X-rays, so dentists use bite tests and magnification to locate them. Treatment ranges from a crown to, in deeper cracks, root canal treatment or extraction, depending on how far the crack extends.
Decay or a failing filling. A cavity that undermines part of the tooth, or an old filling that has cracked or leaked, can make the tooth flex or press on sensitive dentin during chewing.
A “high” bite. A recently placed filling or crown that sits even a fraction of a millimetre too high concentrates force on that tooth. The fix is often a simple adjustment — one of the easiest resolutions to bite pain.
Inflammation at the root tip. When pulp inflammation or infection spreads to the tissues around the root, the tooth becomes tender to pressure — sometimes feeling “taller” than its neighbours. This pattern often accompanies other warning signs described in signs you may need root canal treatment.
Gum-related infection. An abscess in the gum beside the tooth, or food packed between teeth, can cause localized biting pain along with tenderness and swelling of the gum.
Grinding and clenching. People who grind or clench, often at night, can overload their teeth and the ligaments that hold them. Several teeth may feel sore when biting, especially in the morning, and the jaw muscles may ache too.
Sinus pressure. Upper back teeth sit near the sinus floor. During a sinus infection, several upper teeth may ache with chewing or when bending over — typically affecting multiple teeth rather than one.
What does the type of pain tell you?
The way the pain feels can hint at the cause, although only an exam can confirm it.
| What you notice | Possible causes |
|---|---|
| Sharp, brief pain when biting or when letting go | Cracked tooth, broken filling |
| Pain only on a newly filled or crowned tooth | Restoration sitting slightly high |
| Dull, constant ache that worsens with pressure; tooth feels “taller” | Inflammation or infection at the root tip |
| Tender, swollen gum next to the tooth | Gum abscess, food trapped between teeth, gum disease |
| Several upper back teeth ache, worse when bending over | Sinus congestion or infection |
| Sore teeth and jaw in the morning | Grinding or clenching |
| Pain with sweets, lingering pain with cold | Decay, possible nerve inflammation |
Use this as a guide for describing your symptoms, not for self-diagnosis. Two causes can also happen at the same time.
Is it a cracked tooth?
Cracks are one of the more frustrating causes of bite pain because they can be hard to see. Common clues include:
- sharp pain when you bite on something small and hard, such as a seed or grain,
- pain that comes and goes rather than being constant,
- sensitivity to cold that fades quickly,
- difficulty pinpointing exactly which tooth hurts, and
- a history of large fillings, grinding, or chewing ice.
A crack may start in the enamel and spread over time. Caught early, a cracked tooth can often be protected with a crown that holds it together. If the crack reaches the nerve, root canal treatment may also be needed, and a crack that splits the root may mean the tooth cannot be saved. This is why pain from a suspected crack is worth checking soon rather than waiting to see if it spreads. Our article on signs you may need a dental crown explains when full coverage is recommended.
Why does my tooth hurt when biting after a filling or crown?
Mild tenderness for a few days after new dental work is common, especially if the tooth was deeply decayed. However, if a new filling or crown makes that tooth hit first when you close, or if chewing on it is sore after a week or so, the most likely reason is that the bite needs a small adjustment. This is usually quick.
Pain that worsens over time, lingers after hot or cold, or becomes throbbing may mean the nerve is inflamed. That needs to be checked. If you are comparing restorations, see dental crown vs filling for how each one supports the tooth.
Why does a tooth hurt when biting after a root canal?
Tenderness when biting for a few days after root canal treatment is common, because the tissues around the root tip have been irritated by the infection and the treatment. It usually eases steadily. Pain that is getting worse instead of better, or that returns weeks or months later, should be checked. Possible reasons include:
- a temporary filling that sits high in the bite,
- a crack in the tooth or root, which is more likely in back teeth that have not yet been crowned,
- inflammation that has not fully settled, or
- a new leak around the filling or crown that lets bacteria back in.
If your treated tooth is still waiting for its final crown, avoid chewing hard foods on it until the crown is placed.
Is it the tooth, or is it the jaw?
Pain when chewing is not always coming from a tooth. The jaw joints and chewing muscles can also hurt when you bite, particularly if you clench or grind. Jaw-related pain tends to:
- feel like a dull ache in front of the ear, in the cheek, or at the temple,
- come with clicking, popping, or stiffness when opening,
- be worse after chewing gum or tough foods, and
- affect one whole side rather than a single tooth.
Your dentist can check the joints and muscles as well as the teeth. If the jaw seems to be the source, a TMJ assessment can help sort out what is going on.
How does a dentist find the cause of bite pain?
The examination combines your history (when it started, which foods trigger it, whether it lingers) with bite tests on individual cusps, cold testing of the nerve, gum measurements and X-rays. Each cause leaves a different pattern across these tests. This is why describing your pain precisely — sharp versus dull, on biting versus on release, brief versus lingering — genuinely helps.
What to expect at the appointment
- Questions about your symptoms. When did it start? Which tooth, or which side? Does it happen with every bite or only certain foods?
- A look at the teeth and gums. The dentist checks for visible cracks, broken fillings, decay, and swelling.
- Bite testing. You may be asked to bite on a small instrument that presses on one part of a tooth at a time.
- Nerve testing. A cold stimulus can show whether the nerve is healthy, inflamed, or no longer responding.
- Gum measurements. A small probe checks for pockets or signs of gum infection.
- X-rays. These can show decay, bone changes around the root, and the condition of old fillings. See why dental X-rays may be recommended.
- Explanation and options. Our team explains what we found, the treatment choices, and estimated fees before any treatment begins.
Helpful notes to bring
Before your visit, jot down which foods trigger the pain, whether it happens when biting or releasing, how long it lasts, and whether anything makes it better or worse. Also note any recent dental work, grinding, or colds. These details can shorten the search.
What can you do before your appointment?
Chew on the other side, avoid very hard foods, and keep the area clean with gentle brushing and flossing. Over-the-counter pain relief used as directed on the label can help manage discomfort. Do not place aspirin against the gum — it burns the tissue.
A few more tips:
- Choose softer foods such as soups, eggs, pasta, and cooked vegetables.
- Avoid very hot or cold drinks if they trigger pain.
- Floss gently around the sore tooth in case food is trapped.
- Do not chew ice, hard candy, or popcorn kernels.
- Avoid “testing” the tooth by biting on it repeatedly. This can make a crack worse.
Can bite pain go away on its own?
Sometimes it does, for example when trapped food is cleared, a cold settles, or a high filling wears down slightly. But pain from cracks, decay, or root inflammation usually returns or worsens. A tooth that stops hurting after a period of intense pain can also mean the nerve has died, while infection may still be present.
A quiet spell is not a reason to cancel an appointment. If the pain has lasted more than a few days, or keeps coming back, have it checked.
How is pain when biting treated?
Treatment depends on the cause:
- High filling or crown: a small bite adjustment.
- Decay or broken filling: a new filling, or a crown if a lot of tooth is missing.
- Cracked tooth: often a crown; sometimes root canal treatment as well; occasionally extraction if the crack splits the root.
- Root inflammation or infection: root canal treatment, usually followed by a crown on back teeth.
- Gum abscess or trapped food: cleaning the area, and treating any gum disease.
- Grinding: a night guard and, where needed, repairing damaged teeth.
- Sinus pressure: usually improves as the sinus condition settles; your doctor may advise on the sinus itself.
When is tooth pain when biting an emergency?
Book an examination for any bite pain that persists beyond a few days. Seek prompt care if:
- the pain is severe or wakes you at night,
- the gum or face is swelling,
- you have a fever or feel generally unwell,
- a bad taste or pus appears near the tooth, or
- a tooth or filling has broken and left sharp edges.
Guidance for intense pain is covered in what should you do for a severe toothache, and urgent situations are handled through emergency dentistry.
Call 911 or seek emergency medical care for trouble breathing, trouble swallowing, uncontrolled bleeding, major facial trauma or other potentially life-threatening symptoms.
How can you prevent pain when biting?
- Keep up routine checkups so decay and worn fillings are found before they cause pain.
- Wear a night guard if you grind or clench.
- Avoid chewing ice, pens, and hard candy.
- Brush twice a day and clean between your teeth daily to protect both teeth and gums.
- Do not put off recommended crowns on heavily filled or cracked teeth.
Getting a sore tooth checked in Cornwall
Pain when chewing tends to get in the way of every meal, so it is worth sorting out quickly. At York Street Dental Centre on York Street in Cornwall, we examine the tooth, test the bite, and explain what we find in plain language before recommending anything.
Patients come to us from across the city, including downtown, Glenview Heights, and Churchill Heights, and from nearby Lakeview Heights and St. Andrews West. New patients are welcome, and no referral is needed. When you call, tell us if you have swelling or severe pain so we can advise you on how soon to come in.
Book an exam
If a tooth hurts when you bite, call York Street Dental Centre at (613) 932-1620 or request an appointment online. You can also learn more about root canal treatment at our office.
Frequently asked questions
Why does my tooth hurt only with certain foods?
Cracked teeth often hurt with foods of particular textures — grainy bread, seeds — that wedge into the crack. Sensitivity to sweets more often points to decay or exposed dentin. These patterns help the dentist target testing.
My new filling hurts when I chew. Is that a failed filling?
Not necessarily. The most common reason is that the filling sits slightly high in the bite, which a quick adjustment fixes. Persistent or worsening pain after adjustment should be reassessed.
Can bite pain go away on its own?
Sometimes — for example, if food impaction is cleared. But pain from cracks, decay or root inflammation typically returns or worsens. A quiet interval does not mean the problem is resolved.
Is bite pain ever an emergency?
It can be, when accompanied by swelling, fever or severe constant pain — signs of possible infection needing prompt care. Otherwise, a timely routine appointment is appropriate.
Why does my tooth hurt when I bite but not at other times?
Pain that appears only under pressure often points to a crack, a filling or crown that sits slightly high, or inflammation around the root tip. Decay that has weakened a wall of the tooth can do the same. Because the causes differ, a dental exam with bite testing and X-rays is the most reliable way to find which one applies to you.
Can a tooth that had a root canal still hurt when biting?
Yes. Mild tenderness for a few days after root canal treatment is common. Pain that lasts longer or appears later may come from a high temporary filling, a crack in the root, or remaining inflammation. A treated back tooth without a crown is also more likely to crack. Contact your dentist so the cause can be checked.
Sources
- American Association of Endodontists — Cracked Teeth
- Cleveland Clinic — Toothache
- Mayo Clinic — Tooth Abscess
About the author
This article was written by the York Street Dental Centre Team and reviewed for clinical accuracy by the York Street Dental Centre dental team. York Street Dental Centre is a family dental office at 118 York Street, Cornwall, Ontario K6J 3Y8, providing general, preventive, restorative, and cosmetic dental care for patients of all ages.
Our articles explain common dental questions in plain language, cite reputable health and government sources where relevant, and are updated when guidance changes. Read our editorial policy or learn more about our practice.
This content is intended for general educational purposes and does not replace an examination, diagnosis or personalized treatment recommendation from a dental professional.