Sharp Pain When I Bite, But the X-Ray Was Clean

Quick answer: A sharp jolt when you bite or release, with a normal x-ray and nothing visible to the eye, is the signature of cracked tooth syndrome. X-rays do not show cracks that run front-to-back, so a clean film does not mean nothing is wrong.

The call

Miriam, 43, from Givat Sharett, had been living with it for nearly two years. A stab of pain on certain foods, in a particular spot, that vanished within a second. Nuts, crusty bread and pitta were the usual culprits. Twice she had been told the x-rays were fine and that it was probably sensitivity. She had bought three different desensitising toothpastes.

What brought her in was a change in the pattern. The jolt had started arriving on cold drinks too, and lingering afterwards.

What we found

Her x-rays were, indeed, normal. They almost always are. A crack that runs from one side of the tooth to the other lies parallel to the x-ray beam, so it never casts a shadow on the film. Radiographs are excellent at showing decay and infection at the root tip, and close to useless for this.

The diagnosis came from a bite test. We had her bite on a small plastic cusp-loading device, one cusp at a time, and release. Three cusps were silent. On the palatal cusp of the upper left first molar she jumped — not on biting down, but on letting go. That release pain is the classic sign: the crack opens under load, and closing it again irritates the nerve inside.

Under magnification, with the old filling removed and a dye applied, the line was visible running across the floor of the cavity. The tooth still tested vital, but the lingering cold response told us the pulp was becoming irreversibly inflamed. We were near the end of the window.

What we did

We removed the filling, cleaned out the crack line as far as it was accessible, and placed a bonded core that held the segments together. Then, in the same visit, we prepared the tooth for a full crown — the only restoration that reliably stops a cracked molar flexing, because it holds the whole circumference like a band around a barrel.

We deliberately did not start a root canal. Roughly two-thirds of cracked teeth caught at this stage settle once the flexing stops. Starting a root canal on a tooth that did not need one is a decision you cannot take back.

The outcome

The pain on biting stopped the day the temporary crown went on. At the six-week check the tooth tested normally to cold. The permanent crown has been in place two years and the tooth has needed nothing further.

Miriam also had a heavy clenching habit and a scalloped tongue. She now wears a night guard, because the tooth on the other side was showing the same early wear pattern.

What to do if this happens to you

1. Note exactly which foods trigger it. Hard, fibrous and crunchy foods point to a crack; sweet foods point more towards decay.
2. Notice whether it hurts on biting or on releasing. Release pain is the strongest clue.
3. Try to localise it. Chew a piece of soft food on one tooth at a time and find the culprit.
4. Stop chewing on that side until you are seen. Every load extends the crack.
5. Do not accept "the x-ray is clear" as the end of the discussion. Ask specifically for a bite test.
6. Get seen sooner if cold pain starts lingering. That is the crack reaching the nerve.

Sharp pain when you chew? Ramat Beit Shemesh Urgent Dental Care runs a proper crack assessment, not just an x-ray. 055-985-8845 · WhatsApp https://wa.me/972559858845 · Harav Kook 28/1, Beit Shemesh.

Based on real cases treated at the clinic. Names have been changed.