Yesterday the Associated Press dropped news that pretty much everyone has been waiting for: Little evidence exists that flossing actually does anything. And so the people collectively threw their minty-fresh, waxy threads into the trash and muttered, Gobdanged dentist.
But please, lets all cool off for a moment, reach down into the trash can, and retrieve our floss. Because while its true that evidence in favor offlossingis lacking, you should probably still do it. Many dentists have known all along the researchisnt there, and they kept on recommending flossing anyway. Just hear me out—their intentions are pure. (Full disclosure: I was briefly a copy editor at a marketing firm for dentists. It was awful, and it in no way clouds my judgment with this story.)
Dentists tell their patients that flossing removes plaque from between teethgunky stuff that can lead to tooth decay and gum disease. Thats the story, anyway. As the AP pointed out in their piece, studies havent confirmed flossing prevents decay and disease. And the ones that have shown some sort of benefit have been flawed, relying on too few subjects over too little time. Indeed, because the evidence just isnt there, the feds last year stopped recommending flossing to the public.
Heres the thing, though. The lack of evidence for the benefits of flossing is nothing new. To be honest, many of us in the dental public health community have known for years that the information was sparse, says Scott Tomar, editor of the Journal of Evidence Based Dental Practice.
So why keep propagating the myth? Why force the public to stick their hands in their mouths? Well, because while the effectiveness of flossing isnt proven, its also not disproven, at least not yet. Scientists are still gathering string—and its proving difficult.
In the lab, scientists have found that flossing does indeed reduce inflammation and bleeding of the gums, indications that it could theoretically head off gum disease. Theoretically. But these studies only lasted a few weeks, not nearly enough time to track the development of long-term disease.
What you really need to prove the efficacy of flossing is a real-world, longitudinal study. “But when you move the study out into the real world, a large epidemiological study,” says Tim Iafolla of the National Institute of Dental and Craniofacial Research, “the problem is you can’t follow people at home and make sure they’re flossing correctly or flossing when they should be.”
In order to get good data, researchers would have to run a study for years, with groups of both flossers and non-flossers, the latter of which might just habitually floss anyway. That’d cost perhaps $10 million, and that money just aint there. The National Institutes of Health only has so much money to hand out, and flossing isn’t exactly on the top of the list of pressing public health concerns. Funding could come from interested companies like Crest, but critics might rightly pan that research for its potential for bias.
Also an issue: That control group of non-flossers is an ethical problem if flossing does turn out to be an integral part of oral health care. You randomize these people and put them in a situation that has put them at risk, says Tomar, when in fact the standard of care has been to use floss even in the absence of high-level evidence.
And so dentists keep recommending flossing. After all, it’s a low-risk, low-cost addition to a dental hygiene regimen. Even if flossing turns out to be not so effective, it doesnt hurt to do it—though in rare cases overzealous flossers can injure their gums or break dental work. Meanwhile, the risk of not recommending flossing is relatively high: If it is indeed an effective defense against gum disease and tooth decay and dentists tell patients, Eh, screw it, floss if youve got the time, a lot of people are going to end up with problems.
The American Dental Association, for its part, maintains that flossing is effective and continues to recommend it in conjunction with brushing and regular dentist visits. And hell, maybe this whole hullabaloo gets folks more interested in the science of flossing. I think what’s going to happen is its going to trigger good conversation between the public and their dentists, says Marcelo Araujo, vice president of the ADA Science Institute. And that’s what we really want.
So at the very least, talk to your dentist before you do something rash like ritualistically burning your floss.