How many rads are in a dental X-ray?

The exposure one receives from a radiograph/x-ray at the dentist is dependent upon what type of x-ray is taken and how many. Dental x-rays of any kind are much safer/lower radiation exposure than most medical x-ray exposures, especially including CT scans.

CT scan of your head ~ 200 mrem

CT scan of the heart ~ 2,000 mrem

Dental Bitewing ~ 0.5 mrem

(you typically receive about the same or more radiation annually from living in the mountains (closer to outter space) compared to someone at sea level, as you do during a dental x-ray (both of which are typically less than a 1/6th your usual annual exposure to radiation from the environment).)