Doctor, do I really need to take dental x-rays? This is a question frequently posed by our patients and one that requires thoughtful consideration. The reason why people may question or refuse the need for dental x-rays often relates to the issue of safety. No one wants to expose themselves to radiation needlessly, and on this point everyone can agree. However, we cannot overlook the benefits of dental x-rays: They allow us to detect small problems of the teeth and bone of the jaws before they become big problems. So what is the balance? How often can we safely take x-rays and how often should we?

Before answering the question, we must understand a bit about x-ray exposure. Radiation is measured in units called millisieverts. This is a metric measurement, so it uses a similar scale to what we use for distance. One millimetre is 1/1000th of a metre. Dental x-rays are measured in microsieverts. So just as a micrometre is 1/1000th of a millimetre, a microsievert is 1/1000th of a millisievert. To put it another way, it is 1000 times less.

The only films we use are digital, which correspond to the 6th row from the top. As described in the chart, 18 to 20 films is 0.0039 mSv, meaning one film is less than 0.0008 mSv.

The fact is that radiation occurs naturally all around us, to the point where we are naturally exposed to about 4 millisieverts every year. This number increases if we live in a part of the world with longer sun exposure, at higher elevations, if we fly on airplanes, watch television, or smoke cigarettes. A typical digital dental x-ray examination of 4 bitewing x-rays is 0.8 microsieverts. Remember that is 5000 times less than your average natural exposure yearly dose! Dental x-rays are among the lowest sources of diagnostic imaging x-rays used.

Now that doesn’t mean that we need excessive amounts of images. For new patients, Dr. Seminara will review your history, examine your mouth and teeth then decide whether you need radiographs and what type. For most patients, this will mean bitewings and selected periapical images. These can give us valuable diagnostic information about the teeth, bone, roots and other structures of the jaws. Once we know your general dental status, a recall schedule can be fixed with regular x-rays as needed.

A Bitewing X-ray

The average patient in our office who is at low risk (someone who get cavities infrequently) would be recommended to have bitewing x-rays done once every 18 to 24 months. A patient at higher risk would be recommended to have them done every 6 to 12 months. More are taken for patients with advanced needs, such as gum disease or root canals. Emergency visits may also require images to help diagnose the cause of the acute problem. We take care to limit exposure by using digital x-ray sensors and specials machines that specifically target the mouth area, reducing exposure to other body parts. In fact, the body is covered by a protective lead apron for this very purpose.

A Periapical X-ray

Dr. Seminara’s x-ray recommendations are always based on your specific individual needs and the standard of care as prescribed by the Order of Dentists of Quebec and the Canadian Dental Association. Our goal is to take as few as necessary to keep your teeth and mouth in perfect health!