Can an x-ray show a cracked tooth below the gum line? the tooth hurts when i push on it but x-rays show a healthy tooth!

Not always: Radiographs don't reveal everything.. cracks are very difficult to detect. Did your dentist check to see if the tooth was vital (alive)? The nerve could have recently died, spilling toxins into the bone surrounding the tooth, thus the pain when you press on it. No sensitivity to cold or sweets further confirms this. Have your dentist refer you to an endodontist if s/he cannot find out the cause.

Very common: The teeth with cracked tooth syndrome usually have fractures that are too small to be detected on X-rays. People who grind or clench their teeth often develop the cracked tooth syndrome. Treatments for this condition do not always completely relieve the symptoms. Prevention is the key, ask your dentist for a hard night guard fabrication.

Crack: if the tooth has had multiple restorations/fillings it is susceptible to being cracked. If you grind your teeth , that could lead to fractures. Cracks themselves rarely show on Xray, but will sometimes show on CT Scan, which some dentists will have in their office.

Endodontist: See an endodontist for best opinion. CT scan or exam under microscope will sometimes show a crack that cannot otherwise be detected.