This is one of the most common questions dentists get, and it’s a good one.  Our exposure to x-rays is cumulative over the course of our lives, meaning it constantly adds up and never goes away.  Dentists have known this for many decades (long before we entered dental school).  So we are very interested in minimizing the amount of radiation we are all exposed to.  I have to say dentists have done an excellent job.

I just stumbled across a group called the Health Physics Society.  They help provide health physicists with the information they need to do their job, which is “to manage the beneficial use of ionizing radiation while protecting workers and the public from potential hazards”.  (I’d never heaerd of a “health physicist” before.)  Their website has a lot of great information on our radiation exposures- everything from airport screenings and cell phones to tanning salons.

Their page about dental patient issues has some great comparison numbers.  Normal background radiation dose is about 360 mrem per year.  That’s your annual exposure just by living on this planet.  The dose for four bitewing (check-up) x-rays is 0.2 – 0.3 mrem, or less than half of what we are normally exposed to in a day.  A full mouth set of x-rays is equivalent to a little more than one days normal background radiation.

On another page, they state, “differences in background levels between different parts of the country are larger than the effective dose for a bitewing. For example, moving from a lower-background region such as Minneapolis, Minnesota, to a higher-background region, such as Denver, Colorado, for a year would result in an increase in effective dose for that year that is about the same as 30 bitewing exams”.  The US EPA estimates that we are exposed to 2-5 mrem on a cross-country flight, which is more than twice the exposure of a full mouth set of x-rays.

If any of you are concerned about just how much radiation you are receiving when you see your dentist, I encourage you to check out the “dental patient issues” page.

Dr. Steve

Roseville Family Dentist

Dr. Steven Lee graduated from the UCLA School of Dentistry in 1985. He was a dental examiner on the National Health and Nutrition Exam Survey (NHANES III). And he is the leader of the American River Study Club. Dr. Lee has been practicing general dentistry in Roseville CA for the last 18 years.