fb-pixel Skip to main content

To floss, or not to floss? Boston dentists say there’s no question.

Dental floss products.Tony Cenicola/The New York Times

Don’t stop flossing just yet.

A much-circulated story by the Associated Press hints that the government seems willing to pardon our dental crimes — at least the crime of not flossing. Nevertheless, most dentists continue to swear by the practice.

In an unexpected move, the 2015-2020 edition of Dietary Guidelines for Americans, produced by the US Department of Health and Human Services and the US Department of Agriculture, left out any recommendations to floss. This is the first year since 1979 that flossing has been omitted, the AP reported.

The guidelines are written to align with “the current state of scientific evidence on nutrition and health.” So the AP looked at 25 studies from the past decade and found no comprehensive evidence to prove that flossing is beneficial. The government also noted that the efficacy of flossing had never been researched, the AP reported.

Perhaps not surprisingly, many dentists are dissatisfied with the article’s conclusion. In a Tuesday press release, the American Dental Association upheld its recommendation to floss daily, citing plaque removal as a benefit.


“[I]nterdental cleaners such as floss are an essential part in taking care of your teeth and gums,” the release stated. “Cleaning between teeth removes plaque that can lead to cavities or gum disease from the areas where a toothbrush can’t reach.”

Boston-area dentists agreed with the ADA. Dr. Julie Elpers, a prosthodontist practicing with the Dental Partners of Brookline, acknowledged a lack of research supporting the benefits of flossing, but said that doesn’t discount its effectiveness.

“Absence of evidence isn’t evidence of absence,” Elpers said.

Elpers added that the issue could instead be with the design of the scientific studies conducted over the past 10 years.

“There probably isn’t a high level of evidence that says doughnuts are bad for you,” Elpers said. “But that doesn’t mean we don’t know doughnuts are bad for you. It’s not a question of no benefits, it’s a question of no evidence.”


Dr. Keith Foley, a dentist at Harvard Street Dental in Cambridge, took a different approach. Although the AP looked into 25 studies focused on the use of a toothbrush alone versus the use of a toothbrush and floss, Foley said there isn’t that much research conducted on dentistry, and that could have influenced the AP’s findings.

“There’s a limited amount of funding for dental research,” Foley said, “and something as basic as flossing perhaps didn’t get that much funding.”

Dr. Evangelos Papathanasiou, an assistant professor in the department of periodontology at the Tufts University School of Dental Medicine, will keep recommending floss to his patients but said he thinks there are more factors involved in preventing gum disease.

“The future of dentistry and periodontistry involves providing more personalized dental care,” he said.

Papathanasiou recently conducted his own research on the role that stress and the immune response play in causing gum disease. He said dentists must understand each patient’s needs and risk factors, and based on that information try to design a customized therapy regimen.

“No one can argue the statement that someone who doesn’t floss will get disease,” he said, “but definitely by flossing, you can minimize the risk.”

Sonia Rao can be reached at sonia.rao@globe.com. Carly Sitrin can be reached at carly.sitrin@globe.com .