I have a hole in my tooth which is causing me pain. my dentist examined and did xrays and said it is not a cavity. what could this be?

Second Opinion.: Get a second opinion for your satisfaction.Dentists are well trained professionals & would advise you after proper & thorough examination.But, for your satisfaction, you may seek a second opinion.

Fracture ?: Hard to tell without seeing the tooth or the radiograph. Have your dentist re-examine the tooth.

Either: Either a developmental defect or a cavity. Please seek a second opinion. Your Dentist may be absolutely correct, but without examination and xRays can't tell.