Do I have the right to get a copy of my x-rays original images?

I requested copies of my x-rays original images from my dentist because i want to file a formal complaint with the Health Dept. about his bad performance; instead he sent me photocopies. I sent him a letter telling him I didn't want photocopies. A few days later, he sent me a letter telling me that if I wanted copies of the x-rays original images, I would have to pay the amount of $13.00. So, I complied with his request and sent hm a check for the $13 and he sent me another photocopy! I feel he does not want me to have those x-rays. He is hiding something. What should I do?