For decades dentists have been telling patients they should floss, but the effectiveness of flossing has now come into question.

The U.S. government has recommended flossing since 1979, first in a report from the surgeon general and then in the Dietary Guidelines for Americans, published every five years. Under the law, those guidelines must be based on scientific research.

benefits of flossing

An investigation by The Associated Press (AP) last year requested that the Department of Health and Human Services provide evidence that supported the flossing recommendations in the guidelines.

The latest edition of the Dietary Guidelines does not include any flossing recommendations. In a letter to the AP the government noted the necessary research had not been undertaken to determine the efficacy of flossing.

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Difference of opinion

The exclusion of flossing from the Dietary Guidelines has produced divided opinions among dental health professionals.

The American Dental Association (ADA) has encouraged the public to continue flossing, despite the practice not being included in the latest edition of the guidelines.

“The Dietary Guidelines have no bearing on the long-standing recommendation from the Surgeon General, the CDC, and other health agencies to clean between teeth daily ... The bottom line for dentists and patients is that a lack of strong evidence doesn’t equate to a lack of effectiveness,” says a statement on the ADA’s website.

Dr. Matthew Messina, a spokesman for the ADA, and a practicing dentist in Ohio, argues flossing has helped improve the oral health of Americans for decades.

“In the 1950s, just two generations ago, most people passed away in their 60s with dentures or less than all their natural teeth. Now, we have many people living into their 90s and keeping all or most of their teeth all the way to the finish line. Flossing has been an integral part of that success. I see the results every day in my office,” Messina told Healthline.

But some dentists believe more evidence is needed to support universal flossing.

“Recommendations should be made based on demonstrated evidence that the intervention works. It’s not enough to say that we think this will work or it seems logical that it should work. We should know that it works before making a blanket recommendation that everyone do this,” Dr. Robert Collins, professor of dental medicine at the University of Pennsylvania, told Healthline.

It is a view supported by Dr. Philippe Hujoel, Ph.D., a professor of oral health sciences at the University of Washington.

“It seems risky business to promote universal flossing without good evidence. The danger is that it may offer an excuse to patients to adopt or continue eating sugar or to smoke, and to provide possibly an illusion that they will be protected against these harms,” Dr. Hujoel said.

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Technique important

During its investigation into flossing, the AP examined research into the benefits of flossing over the past decade.

Hujoel’s research was one of the 25 studies that were scrutinized. Most of the studies compared the use of a toothbrush with a combination of both flossing and toothbrushes.

Overall the studies suggested the evidence supporting flossing was “weak” and “very unreliable.”

Despite this, the American Dental Association (ADA) has been recommending flossing consistently since 1908. Information on the ADA’s website states that flossing is “an essential part of taking care of your teeth and gums.”

This is a view supported by Australian dentist Dr. David Dunn. He argues excluding flossing from the Dietary Guidelines is an overly simplistic interpretation of limited data.

“From my clinical experience there is a direct correlation between reduction in interproximal caries (decay between the teeth) with those patients who have good oral hygiene habits including flossing,” Dunn told Healthline.

He said it is important patients floss correctly to benefit from the practice.

“Technique is important and good preventative care requires oral hygiene instruction as to how to use floss and flossing aids appropriately. Otherwise damage can be done to the delicate gingival or gum tissues,” he said.

But Hujoel believes patients may have formed the belief flossing could be an antidote to unhealthy lifestyle choices.

“The key point here is to inform patients about the cause of their dental problems and the equivocal nature of the evidence that floss may temper those adverse effects,” Hujoel said. “The issue at stake is not whether to floss or not. The issue is false advertising. In other words, do not promote the notion that washing hair will prevent baldness, or that flossing will prevent decay. Both are unsupported claims.”

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