Cracked Tooth Syndrome and Teeth Grinding

A tooth that gives a sharp jolt when you bite a certain way, then feels normal, often has a crack too fine to see. The pattern of symptoms it produces is known as cracked tooth syndrome, and grinding and clenching are among the habits that make it more likely.

What it feels like

The American Association of Endodontists describes the pain of a cracked tooth as erratic when you chew, sometimes with sudden pain when the tooth meets very hot or cold temperatures, and pain that comes and goes. A 2025 review adds a telltale sign: a brief, sharp pain when you release your bite, particularly on chewy food. Biting flexes the cracked pieces slightly apart, and that motion irritates the pulp inside the tooth.

Pain on biting is the symptom people associate with cracks, but it is not the most common one. In a large US study of nearly 2,900 back teeth with visible cracks, sensitivity to cold was the most frequent symptom. More than half of the cracked teeth had no symptoms at all. The same study found that people who clench, grind or press their teeth together were more likely to have painful cracks.

Why a crack is hard to find

Because the pain comes and goes, patients often cannot tell which tooth it is. The AAE notes that dentists can have difficulty locating it too. X-rays are of limited help: the 2025 review notes that cracks are seldom diagnosed on radiographs, and they may only become suspicious later, once the bone around the tooth has been affected. A normal X-ray does not rule a crack out.

How grinding contributes

AAE guidance for dentists explains that cracks generally develop slowly over time, as the tooth is subjected to repeated habits like clenching, biting stress and temperature changes. Fillings matter too: the AAE notes that a piece of the chewing surface often breaks off around a filling. Fillings or crowns that keep breaking are one of the signs of grinding.

How we look for a crack

There is no single test. A bite test asks you to bite on a small instrument one part of the tooth at a time, to find the spot that reproduces the pain. Transillumination shines a bright light through the tooth, because a crack blocks the light. A staining dye can make a crack line easier to see, and magnification helps. Measuring the depth of the gum around the tooth is another standard check, because a crack that has run toward the root can change it. X-rays, and sometimes a 3D cone beam CT scan, check the bone and rule out other causes. Even so, the AAE notes that no standard examination can predict how a cracked tooth will do long term.

Treatment depends on the crack

The AAE groups cracks into five types. Craze lines are tiny cracks in the outer enamel only. They are painless and need no treatment beyond appearance. A fractured cusp is a piece of the chewing surface that breaks off, often around a filling. It rarely harms the pulp, and a new filling or a crown usually repairs it.

A cracked tooth has a crack running from the chewing surface down toward the root. A crown holds the tooth together and helps protect the crack from spreading. AAE guidance for dentists notes that covering the cusps early can improve the outcome. If the crack has reached the pulp, the AAE describes treatment as a root canal procedure followed by a crown. If it extends below the gum line, the AAE says the tooth can no longer be saved and must be removed. That is why early treatment matters.

A split tooth, often the result of a crack progressing over time, has separate segments. It cannot be saved intact, although sometimes part of it can be kept. A vertical root fracture starts in the root, often causes few symptoms, and may mean extraction, or sometimes endodontic surgery if part of the tooth can be saved.

Two limits are worth knowing. Unlike a broken bone, a crack in a tooth does not heal. And even with treatment, the AAE says some cracks continue to progress and the tooth may still be lost.

Protecting your teeth if you grind

The AAE advises people who clench or grind in their sleep to talk to their dentist about a mouthguard, and to avoid chewing ice or other hard objects. A custom night guard takes the load at night and protects new crowns as well as natural teeth. For daytime clenching, see breaking the clenching habit and our teeth grinding treatment page.

If a piece of tooth has broken off, or a tooth has suddenly split, follow our first-aid steps for a broken or cracked tooth and call us at (703) 250-5072.