How Safe Are Dental X-rays?

When x-rays are passed through your mouth, more x-rays are absorbed by the denser parts of your mouth, such as teeth and bone, than by soft tissues. The x-rays strike the film that is behind your tooth, and this creates an image on the film. Tooth decay, infections, gum disease and other signs of dental change in your mouth appear darker because of more x-ray penetration.

Dentists consider x-rays one of the most useful tools in helping patients maintain good oral health. X-rays help dentists diagnose relatively common disorders such as cavities, periodontal disease and infections, and some of the more uncommon problems, such as cysts, abscesses and tumors.

X-rays can also allow your dentist to determine whether a child's permanent teeth are erupting properly and with correct spacing. In general, children need x-rays more often than adults because their mouths grow and change rapidly, and they are more susceptible to tooth decay than adults.

In today's digital age, dentistry is making great advances in lowering the radiation dose administered during a dental x-ray. In the 1930s and 1940s, the cone used for x-rays covered most of the head and neck. Today, the cone is very small, so radiation is only pointed at the small spot where the x-ray film is located.

Many of the critical organs that might show radiation effects are not in the path of radiation, and the use of lead-lined, full-body aprons protects your body from stray radiation. While your dentist takes this precaution to protect your, stray radiation is almost nonexistent with the modern dental x-ray machines. (By law all x-ray machines in the U.S. are checked for accuracy and safety at least every two years, in some states, more often.) Also, advancements in x-ray film mean that the film requires less radiation to develop the same quality picture.

An even newer advance is digital x-rays using sensors that feed the images to a computer. The digital x-ray system is more sensitive than dental x-ray film systems, so exposure to x-rays is cut by as much as 90 percent.