The mere mention of the word radiation elicits unpleasant thoughts and images for most people. Many of us associate radiation with nuclear bombs, cancer, and a host of other negative ideas. During my weekend course in Costa Mesa, CA with Sirona Dental, the topic of radiation exposure at the dental office was brought up. At this meeting we were discussing Cone Beam CT radiation, but nonetheless dental radiation is an interesting area which requires periodic review. Although patients don’t inquire about radiation near as much as they used to, it remains an area of conversation periodically at our office; so I’ve decided to take this opportunity to delve into the subject just a bit.
All life on this plant is exposed to radiation simply as a consequence of living on earth. The largest contributor of environmental “background” radiation is from radon, a product from the breakdown of uranium. The source of the radon can be terrestrial, cosmic, or naturally occurring. Radiation also is present in our food (Yuck!), for example bananas have radiation in them. In fact, the radiation from one 3D dental scan on a Sirona CBCT machine is equivalent to the radiation from eating 1000 bananas. Among the countless other sources of radiation, air travel, as we know, also exposes us to elevated levels of radiation due to the altitude. With this plethora of radiation sources, the truth is the radiation exposure from dentistry is insignificant. The amount of radiation from dentistry for the average patient is equal to approximately one quarter of one percent of the total radiation exposure.
Let’s try to clear the air and discuss what X-rays are. X-rays are energy stored as waves and they are indistinguishable from visible light. Actually, the sole relevant difference between light and x-rays involves the fact that light possesses inadequate energy to pass your body, while x-rays are strong enough to pass through the body. Both light and X-rays are capable of producing an image on photographic film, and as a consequence both are employed to produce pictures. Light creates photographs of the outside of objects, x-rays produce pictures of the inside of things, including living things (radiographs).
An X-ray unit known as a rem is used to measure radiation. Advances in x-ray equipment, especially digital technology like our office uses, produces a good x-ray image using substantially less radiation than was needed in the past. A typical dental x-ray image exposes you to only about 2 or 3 milli-rem.
Most studies on cancer predict the disease can originate as a result of an accumulation of radiation over time. Of course dangerous short term radiation exposure, such as that produced by an atomic bomb, could also trigger the development of cancer. There appears to be no clear reason why cancer is triggered or what exactly triggers it.
Overall, the exposure from radiation at the dental office is not something patients should lose sleep over. One only needs to simply compare the radiation from a dental office to that from other sources. Several examples include smoke detectors (less than 1 milli-rem per year), living in a brick house (about 10 milli-rem per year due to radioactive materials in the brick), cooking with natural gas (about 10 milli-rem per year from radon gas in the natural gas), and reading a book for 3 hours a day (about 1 milli-rem per year due to tiny levels of radioactive materials in the wood used to make the paper).
Now I don’t want to break up any marriages with this next one, but did you know that you receive about 2 milli-rem per year from sleeping next to someone? This is because all humans have very small amounts of naturally occurring radioactivity in our bodies. Now obviously you wouldn’t refuse to travel on an airplane, reside in a brick house, read books, live with no smoke detectors, or sleep with your spouse solely because of the small amount of radiation you are exposed to from these sources. Dentists learn crucial information by interpreting your dental x-rays, and this information directly leads to your teeth remaining healthy. Unless directed by a physician you should not refuse dental x-rays because of the very small amount of radiation you receive from them.