Dental x-rays can be helpful in making a diagnosis. They are not necessary on a regular or routine basis. They should be prescribed after a careful oral examination when the dentist believes there is a problem.
As a good consumer, you should ask what health benefits will be provided by an x-ray, disclose pregnancy and keep track of radiation exposure. You should also pass this information along to your dentist or physician and insist that protective shields be used with dental x-rays.
On the other hand, patients should not refuse an x-ray that is required for proper diagnosis. The minimal risk from the x-ray is much less than the consequences that may arise from an improperly diagnosed dental condition.