Q: It seems as if every time I visit the dentist, I’m asked to get X-rays. Will this increase my risk of cancer, and how can I square that with the potential benefits?
Dental X-rays are essential for oral health. They can help dentists spot issues like cavities, abscesses, abnormal growths and gum disease, often before they become serious.
But getting X-rays at regular dental cleanings can cause anxiety for some. Dental X-rays emit a form of energy called ionizing radiation, which can damage DNA and increase the risk for cancer. So is it risky to get this type of imaging regularly?
The amount of radiation you’re exposed to during dental X-rays is very low, said David J. Brenner, director of the Center for Radiological Research at Columbia University. It’s much lower than it was decades ago, and often less than the total radiation you’re exposed to every day from your environment, such as from the sun, space and materials in the ground like rocks and soil, he said.
Even so, experts said that dentists should administer X-rays only when a patient needs them, such as when a practitioner notices a potential problem during an exam and needs more information, said Dr. Erika Benavides, a dentist and oral and maxillofacial radiologist at the University of Michigan School of Dentistry.
“The clinical exam should always come first,” she said.
How much radiation do X-rays emit?
Different kinds of dental X-rays release different amounts of radiation. A typical series of bitewing X-rays — in which a patient bites down on a wing-shaped device to hold X-ray film in place — gives off about five microsieverts of ionizing radiation, said Sanjay M. Mallya, an oral and maxillofacial radiologist at the University of California, Los Angeles School of Dentistry. That’s less radiation than you’d be exposed to in a typical day, he said.
Panoramic X-rays — in which you rest your jaw on a surface and the X-ray rotates around your head — usually emit about 20 microsieverts of radiation, or two and a half days’ worth of background radiation, Dr. Mallya said. This is similar to the amount of radiation you would be exposed to during a five-hour airplane flight. A chest CT scan, on the other hand, exposes the body to two years’ worth of background radiation, he said.
Dental X-ray exposure levels are very low — and much lower than they used to be, Dr. Brenner said. “Over the last 30 years or so, the technology has improved,” he said. While it’s possible that these low levels of radiation may increase the risk for cancer, Dr. Brenner added, the risk is “small compared with all the other cancer risks we face.”
Even when considering cumulative exposure over a lifetime, Dr. Mallya explained, the risk from routine dental X-rays would be “negligible,” he said.
According to the American Dental Association and the American Academy of Oral and Maxillofacial Radiology, dental X-rays are safe for pregnant women and their fetuses. “The doses from dental X-rays are 10,000 to 30,000 times lower than that needed to cause these effects,” Dr. Mallya said.
Both organizations also say that you don’t need to wear a protective apron or thyroid-protecting collar during dental X-rays, even if you’re pregnant. Lead aprons don’t offer useful protection, Dr. Benavides explained, and they can interfere with image capture. (These guidelines are relatively new, so some states, like California, still require the use of protective aprons.)
Are X-rays always recommended?
There are many situations in which dental X-rays are needed, Dr. Benavides said. They can help your dentist spot cavities that have developed in hard-to-see places, such as between teeth. They are also helpful for identifying bone loss that results from gum disease, and cysts and tumors that can grow in or around the jaw, Dr. Benavides said. Dentists may order X-rays for children to see where their underlying permanent teeth are and how those are growing.
But dental X-rays aren’t always necessary, and dentists and hygienists should not routinely administer them at the beginning of every cleaning, Dr. Benavides said. Although the risks associated with X-ray radiation are low, it’s best to minimize unnecessary exposure when possible.
In clinical recommendations published in The Journal of the American Dental Association in 2024, experts — including Dr. Benavides — said that clinicians should order dental X-rays only after they have conducted a clinical exam suggesting there could be a problem worth investigating.
Under these guidelines, a low-risk patient who doesn’t regularly get cavities may need X-rays only once every two to three years, Dr. Benavides said. Unfortunately, this is not what typically happens, Dr. Brenner added. Many people are given routine dental X-rays before they are examined, and that’s “not ideal practice,” he said.
If a dental hygienist orders routine X-rays before you see your dentist, Dr. Benavides suggested asking them to hold off. “I would say, ‘I would feel more comfortable if someone examines me first to determine if I really need these,’” she said. A dentist should always explain why they are necessary and how they will benefit your health.
