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X-Ray Safety

X-rays help dentists diagnose common problems such as cavities, gum disease and some types of infections. They allow dentists to see inside a tooth and beneath the gums. Without them, more disease would go unchecked. Treatment would begin later. As a result, people would have more pain and lose more teeth.

The X-rays used in dental and medical offices emit extremely small doses of radiation. However, many small doses over time can damage cells. That's why experts say that X-rays should be used with caution and only when necessary.

As a patient and a parent, you can help increase X-ray safety. Talk to your dentist about how often you or your children need X-rays and why.

Learn the guidelines "] for how often dental X-rays should be done. Dentists use the individual clinical exam and these guidelines when they decide how many and how often to take dental x-rays. If your dentist orders more frequent X-rays, ask how they would help your treatment plan.

If you are moving and changing dental offices, ask for copies of your X-rays. Don't repeat them at your new office. Ask your dentist what techniques are used to limit your exposure to radiation.

Less Radiation for Safer X-Rays

Several changes have reduced radiation exposure in dental X-rays through the years:

  • Lower X-ray dose — The single most important way dentists keep their patients safe from radiation is by limiting the dose. The intraoral dental x-ray machine uses a small cone. This limits the x-rays to an area less than three inches in diameter. X-ray machines also are well shielded. Very little radiation exposure occurs beyond the diameter of the beam.
  • Better film — The speed of films used for dental X-rays has been improved. The fastest speed film (F-Speed) greatly reduces the amount of radiation needed to obtain a good picture. Therefore, patients are exposed to less radiation.
  • Digital X-rays — These newer X-ray machines reduce radiation by as much as 80%. It's estimated that one-third to one-half of U.S. dentists use this technology.
  • Regular inspections and licensing — State local health departments regularly check X-ray machines to make sure they are accurate and safe.
  • Lead shields — Before you get X-rays, you will be covered from the neck to the knees with a lead-lined full-body apron. Many states require these shields. They prevent radiation that bounces off the area being X-rayed from hitting your body. With a dental radiograph the main concern for scatter radiation is to the neck, which is why we use a thyroid shield. The American Academy of Oral and Maxillofacial Radiology recommends the use the thyroid collar, for patients under age 30. Lead shields are used routinely in the dental office; however, they don’t really serve any purpose on the torso part of your body. That is because the amount of scatter radiation to the torso is not detectable. For pregnant patients’ dental offices double lead shield when taking x-rays. If your child is having X-rays, make sure the apron extends all the way to the thighs to protect the genitals and reproductive organs. Children and younger adults are at greater risk for radiation-induced thyroid cancer than older adults.
  • Intraoral ParallelingTechnique — This technique uses a device that holds the x-ray film and helps the dental staff to position the x-ray cone. It enables the dentist to take accurate images and reduces the need to retake images.
  • Limited use of X-rays— Dentists take X-rays only when they believe they are necessary for an accurate dental assessment or diagnosis.

Cone-Beam CT: 3-D Images, More Radiation

In recent years, some dentists have begun using cone-beam computed tomography (CBCT). These machines produce three-dimensional images of the teeth and jaw bones. Cone-beam CT exposes patients to more radiation than a standard full-mouth series of X-rays or a panoramic X-ray. Therefore, cone-beam CT should be used only where it provides a clear advantage over standard X-rays.

For selecting and placing implants, cone-beam CT is appropriate. But it is not needed for diagnosing cavities or periodontal disease. Standard X-rays also are fine for most orthodontic cases. Cone-beam CT can be useful in complex cases, however, to assist with treatment planning.

Updated- November 20, 2020



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