Do you really need to floss?

If you’ve paid attention to the news over the past month, you’ve likely read an article or two about the benefits — or lack thereof — of flossing.  These articles have appeared in major news outlets across the country including the New York Times, the Washington Post, the Los Angeles Times and many more.

Have you wondered what all of the fuss is about?  Here’s what happened.  A reporter with the Associated Press began researching flossing last year based on a recommendation from his son’s dentist. He looked up the available data and filed a Freedom of Information Act request with U.S. Departments of Health and Human Services and Agriculture. (Flossing has always been part of the Dietary Guidelines for Americans, which, by law have to be based in science.)

What happened next was surprising. When the U.S. government issued new dietary guidelines in January, it dropped the recommendation for flossing. That’s because there is no definitive evidence that flossing is beneficial. So what does the evidence say?

A Cochrane Collaboration report published in 2011 reviewed twelve clinical trials which involved more than 1,000 participants. The report measured two factors: whether flossing helped to prevent tooth decay and whether it helped to prevent gum disease. The review found no evidence that flossing helped prevent tooth decay or cavities. It did find some evidence that flossing reduces gum bleeding compared to brushing alone.

Other systematic reviews published in 2008 and 2015 found flossing did not help to remove plaque but may result in some improvements in gum disease.

A review published in 2006 did yield some interesting results: In one study, children with low exposure to fluoride visited the school nurse every day for help with flossing. These children had a significant reduction in the cavities found in between their teeth. These results raise the question of whether studies find flossing ineffective because the average participant does not floss properly.

In any case, there is clearly a mixed bag of evidence here.  It’s true, there is not strong data that flossing prevents cavities. But there is limited evidence that flossing can help prevent and improve gum disease. If you already have a flossing routine, it’s probably a good idea to continue; and if you’re at risk for gum disease, flossing could help you.