January 21, 2014

Dental X-Rays: Are they safe? Let's Talk!

Experts Raise Questions about Controversial Dental X-Ray Study

A recent study that claimed to have found a correlation between dental x-rays and the most common kind of brain tumor made headlines across the country and left many patients worried and confused. But some of dentistry’s top experts say the study has some serious problems.

Questionable Design

These problems start with the study itself. To reach their conclusion, the authors asked two groups of people – one group that had been treated for a type of brain tumor called meningioma and a second group who had not -- to recall details of dental care they’d received at four stages of their lives: before age 10, between ages 10 and 19, between 20 and 49 and up to age 50. Specifically, they were asked the number of times they’d received bitewing, full mouth or panoramic x-rays.1

Patients’ memories were the only resource. There was no effort made to back those memories up with dental or insurance records.

Given that most people have difficulty remembering even recent commonplace events, it’s hard to put much faith in a study that asks them to remember dental visits when they were ten.

Flawed Outcomes

Not surprisingly, experts also raised question about the study’s outcomes. For example, Dr. Alan G. Lurie, the head of radiology at the University of Connecticut School of Dental Medicine and the president of the American Academy of Oral and Maxillofacial Radiology, called it a “very flawed study” and characterized one of its outcomes as “biologically impossible.”2 As he explains it, the researchers asked participants whether they had ever had a bitewing x-ray and whether they had ever had a full mouth series and, based on their answers, determined that those who had a bitewing x-rays had 50 to 100 percent greater risk of meningioma.

“That’s biologically not possible.” Says Dr. Lurie, “because the full mouth series has two to four bitewings plus another 10 to 16 periapicals...They are showing that one bitewing has 50 to 100 percent greater risk than a full mouth series that has multiple bitewings plus a bunch of other films.”3

Comparing Apples and Oranges

To make things even worse, comparing x-rays study participants reported from decades ago to today’s x-rays is like comparing apples and oranges. In the words of the Academy of General Dentistry, “The study’s findings are not applicable to modern dentistry because the study was based upon an examination of outdated radiographic techniques which produced considerably more radiation than patients would be exposed to today.”4

Today’s x-ray techniques and equipment  are capable of “limiting the area and time of exposure and reducing any possible risks while providing the highest level of diagnostic benefits,” says the organization’s president, Howard Gamble, DMD, FGD.5

In fact, many offices today have completely abandoned traditional film x-rays in favor of digital x-rays that reduce radiation exposure by up to 80%.

Where We Stand

At our office we’re committed to giving you the very best care – and today’s safe and efficient x-rays are one of the key tools we use to do that. Without them, no matter how carefully we looked there would be cavities between teeth that we’d miss and we wouldn’t be able to catch periodontal (gum) disease in its earliest, easiest-to-treat stages.

As for how often we recommend x-rays, there’s no one-size-fits-all policy. Our recommendations depend on your specific needs.

If you have any questions or concerns about the study or about dental x-rays in general, please feel free to give us a call. We’ll be happy to discuss this important issue with you.


  1. Williams, Jean. "Experts question X-ray study", ADA News, April 13, 2012. http://www.ada.org/news/6979.aspx
  2. Ibid.
  3. Ibid.
  4. Academy of General Dentistry. "The Academy of General Dentistry (AGD) Sets the Record Straight on Dental X-Rays" April 10, 2012. http://www.knowyourteeth.com/infobites/abc/article/?abc=t&iid=342&aid=10870
  5. Ibid.