Cracked tooth

Because the crack flexes. When you bite down, the segments of the tooth are pressed together; as you release, they spring apart and the movement stimulates the nerve inside, producing a sharp, brief pain. This release pain is the classic sign of a cracked tooth and is different from the pattern seen with decay or infection. It is worth describing exactly this way at your appointment, because it directs the diagnosis efficiently.

It depends almost entirely on where the crack runs. A fractured cusp or a crack confined to the crown of the tooth is frequently restorable, often with an onlay or crown that holds the tooth together. A crack extending below the gum into the root, or a vertical root fracture, generally cannot be restored predictably. This is why diagnosis matters so much: the treatment decision follows from the extent of the crack, not from how painful it is.

Radiographs are two-dimensional images, and a crack only shows if it happens to run in the plane the beam passes through. Most cracks run in a direction that makes them effectively invisible. This is genuinely a limitation of the technology instead of an oversight. Diagnosis therefore relies on bite testing, transillumination, dye staining, magnification and sometimes removing a restoration to look underneath. Radiographs are still taken, largely to exclude other causes and assess the bone.

Where a tooth is cracked but still intact, a restoration that covers the cusps is the standard approach because it stops the segments flexing apart under load. That coverage may be achievable with an onlay instead of a full crown; an onlay conserves more tooth, so it is worth asking whether the more conservative option is possible. If the pulp has been involved, root canal treatment may be needed first, and the coverage still follows.

It is a term used for the pattern of symptoms produced by an incomplete crack: intermittent, hard-to-localize pain on chewing, often with sensitivity to cold, in a tooth that looks unremarkable on examination and radiographs. It is often diagnosed after other causes have been excluded, and it can take more than one appointment to identify. The name describes the presentation, not a distinct disease, and the treatment depends on where the crack turns out to run.

No. Unlike bone, tooth structure does not repair itself, so a crack does not close or heal. Symptoms may fluctuate, and that can give a false impression of improvement, but the crack remains and tends to propagate under repeated loading. Because a crack that extends below the gum turns a restorable tooth into an unrestorable one, waiting for symptoms to settle is usually the option with the worst expected outcome.

A painless chip is often minor, but it still deserves assessment for two reasons. First, a chip can leave a sharp edge that traumatises the tongue or cheek, or expose dentine that will become sensitive. Second, what looks like a simple chip can be the visible part of a larger crack running deeper. If it is genuinely superficial, smoothing or a small bonded repair is usually all that is needed, but that is a judgment made after looking, not before.

Large fillings that leave thin remaining walls, grinding or clenching, biting hard objects such as ice or unpopped popcorn kernels, an uneven bite concentrating force unevenly, and simply age-related brittleness in a heavily restored or root-treated tooth are the common contributors. Often more than one factor is present together. A large old filling in a tooth that also grinds at night is a particularly common combination.

There is no safe waiting period, because a crack does not heal and tends to propagate further under ordinary chewing forces instead of staying static. A crack confined to the crown today can, over weeks or months of continued loading, extend below the gum and turn a restorable tooth into one that must be extracted. Prompt assessment when release-pain first appears gives the widest range of treatment options.

It can help by reducing the forces reaching the tooth during sleep, particularly where grinding or clenching is a contributing factor, but it does not repair a crack that already exists; that still needs its own direct treatment, typically a protective restoration covering the cusps. A night guard is best understood as protecting the whole dentition against further cracks, alongside treating the one already present.

If the crack has propagated deeply enough to reach or irritate the pulp, the nerve can become irreversibly inflamed in the same way it would from deep decay, and a filling alone cannot resolve that internal inflammation. Root canal treatment removes the affected tissue, after which a protective restoration covering the cusps is placed to stop the crack from flexing and progressing further.

Back teeth, particularly molars with large existing fillings or previous root canal treatment, are disproportionately affected because they bear the heaviest chewing loads and often have less remaining sound structure to resist flexing under that force. This is part of why a large filling on a back tooth is a genuine warning sign worth discussing with your dentist before, instead of after, a crack develops.