> That 1948 study of 43 machines in Detroit showed ranges from 16 to 75 roentgens per minute. In 1946, the American Standards Association had issued a safety code for industrial use of X-rays, limiting exposure to 0.1 R per day.
I'd be curious how much a typical modern dental x-ray emits, but we no longer measure in roentgens these days as we have better measures of the actual dose (sieverts).
Less negligible are CT scans, which can expose you to multiples of the average annual background dose in a few minutes.
That's still relatively low level exposure. But there isn't really a safe minimum exposure level, and it's certainly not something you'd want to have regularly.
That's 2 years (CT) and 10 days (x-ray) of exposure to sea level background radiation respectively.
https://www.iaea.org/resources/rpop/health-professionals/den...