I'm sure the dentist will know, however be very careful of xrays at the dentist. There was an article today in usa today about the effects of the thyroid gland and x-rays during pregnancy. The study was very conclusive that women who had dental xrays while pregnant gave birth to low-birth weight babies and there were other complications as well. It had something to do with the xray affecting the thyroid gland, which affects the fetus. If you want to read more about this go to usa today's website and look under headlines on april 29th. Other than that, your dentist should have all the answers, if not call your ob-gyn

Thanks!