Ask the Dentist: How often do I need X-Rays?

As a society we are taught that radiation is scary and bad. That it can cause cancer. We have seen the three-eyed fish exposed to nuclear waste on the Simpsons and watched as an ordinary man was bit by a radioactive spider and turned into Spiderman. But, are you aware at how beneficial radiation can be? X-rays are a type of radiation that help to diagnose bone disease, bone loss, infections in the root of the tooth, abscesses, cysts, unseen decay between teeth and sometimes even tumors.

When an x-ray is taken of your tooth, the film is the small square that is placed on the tongue-side of the tooth. The camera is then aimed at the tooth that will be imaged and a picture is taken. The act of the "picture" is really a small amount of radiation that leaves the camera in the form of a gamma ray, it cannot pass through thick material such as a tooth. So, the image left on the film only shows dark areas where the rays passed through air or your skin to react on the film. The rays can pass through cavities or cracks in your teeth (because these areas are mostly air) and these will show up as small, dark, cloudy areas on the film as well. Your dentist has many years of schooling to determine how to read the radiograph and to look for areas of the tooth that appear darker or cloudy.

Dr. McCargar at Scottsdale Dental Arts says, "The need for x-rays is dependent on the patient's particular situation. Patients with high risk factors for decay might require x-rays every 6 months during their cleaning and exam. High risk factors include dry mouth, recent decay, or gum disease. Patients with low risk factors for decay might require an x-ray every 12 to 24 months." Often dental insurance does not cover x-rays more frequently than every 12 months.

This small amount of radiation that you receive during an x-ray is not dangerous or hazardous for your health. High speed films and lead apron shields allow dentists to take a complete oral series with exposure 800 times lower than a chest x-ray. Digital dental x-ray systems further reduce exposure by 50 percent.