I don't know anything about the differences. All I have ever seen was the regular ones. Whatever has the least radiation is of course going to be safer as far as radiation exposure. I assume that is digital. A good Dentist should be able to use either one. If you are going to a Biologic Dentist, which I recommend everyone does, then you should get a panoramic x-ray. If you do get the standard type of x-ray, I recommend taking anti-oxidants beforehand to protect you as much as possible from the radiation.