Cracked tooth syndrome: why it hurts to bite and what can be done

If you get a sudden, sharp pain when you bite on something hard, and it is gone a second later, you may have a cracked tooth. Dentists call the pattern cracked tooth syndrome. It usually affects a back tooth, it often hurts most as you let go of the bite, and cold drinks can set it off too. The awkward part is that the tooth tends to look normal, both in the mirror and on an X-ray. This guide explains why that happens, how a dentist tracks the crack down, and what the treatment options are, from a simple cover to removing the tooth.

What cracked tooth syndrome feels like

The pain is quick and sharp rather than a dull ache. People describe it as an electric jolt, or as "biting on foil". It comes from one area, but you may not be able to say which tooth, because the nerves in the back of the mouth are not good at pinpointing.

Common signs include:

• A sharp pain when chewing, often on seeds, nuts, crusty bread or a piece of gristle
• Pain that is worse when you release the bite than when you clamp down
• A twinge with cold food or drink that fades quickly
• Pain that comes and goes for weeks or months, so you start chewing on the other side without thinking

Between these moments the tooth usually feels fine. That on-off pattern is why many people put off seeing a dentist, and why the problem can drag on for a long time before it is found.

Why the tooth hurts only sometimes

A crack splits the tooth into two pieces that are still joined. When you bite, the two parts move apart very slightly. That movement pushes fluid along the tiny tubes inside the dentine, and the nerve in the centre of the tooth reacts. When you open your mouth, the pieces snap back together, which is often the sharpest moment of all. A 2010 review in the British Dental Journal describes this release pain as one of the most telling features of the condition.

If bacteria get into the crack over time, the nerve can become inflamed. At that stage the pain often changes: it lasts longer after cold, it may throb, and it can start without any trigger. That shift matters, because it changes the treatment.

Who gets cracked teeth, and why after 50

Cracks build up over years of chewing. Published reviews point to the same risk factors again and again:

• Large old fillings. A big amalgam filling leaves thin walls of tooth around it. Those walls can flex and split, especially on lower molars and upper premolars.
• Grinding and clenching. Bruxism puts heavy, repeated force on the teeth, often at night. The NHS page on teeth grinding notes that many people do not know they do it.
• Hard foods and habits. Ice, boiled sweets, olive stones, bones and opening packets with your teeth all raise the risk.
• Age. Teeth become less elastic with time, and most of us have more fillings by our fifties and sixties.
• Root-filled teeth without a crown. These teeth are more brittle and can split if left uncovered.

Cracks in front teeth are less common and usually follow a knock or a fall rather than slow wear.

Why cracks are so hard to find

A dental X-ray is a flat picture taken from the side. Most cracks run from front to back across the tooth, in line with the X-ray beam, so they do not show. They are also often finer than a hair. A normal X-ray therefore does not mean you are imagining the pain.

Instead, a dentist pieces the diagnosis together:

1. Your story. When it hurts, what sets it off, and whether it hurts on release. This is often the most useful part.
2. A bite test. You bite on a small plastic tool placed on one part of the tooth at a time. Pain from one cusp, but not the others, points to the crack.
3. A close look. Drying the tooth, shining a bright light through it and using magnification can show a crack line. Sometimes a dye is used to stain it.
4. Removing an old filling. If a large filling is present, the crack may only be visible once it is taken out.
5. Nerve tests and X-rays. These do not find the crack itself, but they show whether the nerve and bone are healthy, which decides the treatment.

A 3D (CBCT) scan can sometimes show bone loss next to a deep crack in the root, but it rarely shows the crack itself. Its main use here is ruling other problems in or out.

Types of crack, and why it matters

Not every line in a tooth is a problem. The outlook depends on where the crack runs.

This is why early treatment helps. A crack that is held together today may be a split tooth in a year.

Treatment: from a cover to removing the tooth

The aim is to stop the two parts of the tooth moving, so the crack cannot open and close with each bite. The 2021 review in Pain Research and Management lists the options in roughly this order:

• A band or temporary crown first. If the dentist is not sure the nerve will settle, a temporary cover is fitted for a few weeks. If the pain goes, the crack is very likely the cause and a permanent cover can follow.
• A bonded filling or onlay. For a small crack or a broken cusp, a bonded restoration can cover the weak part of the tooth and hold it together while keeping more natural tooth.
• A full crown. For a crack across the tooth, a crown grips it from the outside and spreads the biting force. This is the most common long-term answer for a cracked molar.
• Root canal treatment. If the nerve is inflamed or has died, it needs root canal treatment, and the tooth then needs a crown to stop it splitting.
• Extraction. If the crack runs deep into the root, or the tooth has split, it usually cannot be saved. The gap can then be filled with an implant, a bridge or, in some cases, left.

No dentist can promise that a cracked tooth will last for ever, even after a crown. Most covered teeth do well, but a small share go on to need root canal treatment or removal later. You should be told this before treatment starts, not after.

What you can do in the meantime

Until you see a dentist, try to protect the tooth:

• Chew on the other side and avoid very hard or sticky foods
• Cut food into smaller pieces rather than biting into apples or crusty rolls
• Avoid very cold drinks if they trigger it
• Take paracetamol or ibuprofen as the packet directs, if you can take them
• If you grind your teeth, mention it; a night guard can protect the treated tooth later

Do not wait for the pain to go away on its own. It often does, for a while, and then comes back worse.

How we approach a cracked tooth at Precious Dental

Many patients who contact us about crowns mention a back tooth that "goes" now and then. We treat that as a question to answer before any plan is final. At our clinic in Antalya the dentist checks the tooth with a bite test and a close look, reviews your X-ray and 3D scan, and tests the nerve. Where we can, we prefer to keep healthy tooth tissue, so if the dentist thinks a smaller bonded repair will hold a minor crack, that is what your plan will say. A larger crack usually needs a crown. For back teeth that is usually zirconia (£150 per tooth); E-max crowns are another option the dentist may discuss. If a tooth is too badly split to save, we will say so and explain the options, which may include an implant. Our written guarantee covers crowns for five years, with conditions in the written terms, such as wearing a night guard if you grind.

If you have several cracked or heavily filled teeth, it is worth asking whether they should be treated together. Our page on full mouth crowns explains when that makes sense and when it does not.

Sources

1. Li F et al. Review of Cracked Tooth Syndrome: Etiology, Diagnosis, Management, and Prevention. Pain Res Manag 2021
2. Banerji S et al. Cracked tooth syndrome. Part 1: aetiology and diagnosis. Br Dent J 2010
3. NHS: Toothache
4. NHS: Teeth grinding (bruxism)

Checked October 2026. Where we give our own view as a clinic, we say so.