ADA questions conclusions in study linking dental floss with toxic chemicals

The Association commented in January on the release of research that the ADA said "may raise unwarranted concern about the safety of certain types of dental floss" by continuing to encourage people to clean between their teeth daily.

The study, "Serum Concentrations of PFASs and Exposure-related Behaviors in African American and Non-Hispanic White Women," was published in January in the Journal of Exposure Science & Environmental Epidemiology.

PFAS are a class of exceptionally stable chemicals that repel both oil and water. The study measured the concentration of 11 different PFAS analytes in blood samples from 178 women and found that those who self-reported using Glide dental floss had higher levels of one, PFHxS, than those who didn't, according to the study authors.

In its statement, the Association said the ADA Science Institute finds the study data "insufficient to support the conclusions presented," pointing out that among the study's shortcomings were that they measured a marker for PFTE, even though the women in the study who reported using Glide were found to have elevated levels of PFHxS.

"PTFE is often used in food and beverage, pharmaceutical and cosmetic applications," the ADA statement says. "The fact that the researchers were able to find the PTFE marker in several brands of floss does not mean that it is the source of the PFHxS in the women. Given that this was a retrospective study including self-reported use of products, there are likely many other differences between women who did and did not report having used the brand of floss mentioned."

The full study can be read online at by searching for the article title. The ADA's full statement is on under the "Press/Media" tab.