Is Flossing Bullshit?

In a bombshell piece of investigative journalism by Associated Press reporter Jeff Donn, Americans learned on Tuesday that more than a century's worth of admonitions from dentists about how important it is to grind strands of filament into your gums a couple times a day until you bleed might just be bullshit.

Donn pressed the American Dental Association (ADA) to explain its conclusion that "flossing is an essential part of taking care of your teeth and gums." He also tried to find the federal government's scientific basis for putting flossing in the list of dietary guidelines proffered by the Department of Health and Human Services every five years since 1979. It turned out there was practically no hard science involved in either one.

The ADA's representative "acknowledged weak evidence, but he blamed research participants who didn't floss correctly," writes Donn. The federal government, meanwhile, removed the guideline after Donn inquired, and when he asked for an explanation, the Fed "acknowledged the effectiveness of flossing had never been researched, as required."

So is flossing a waste of time?

According to Los Angeles dentist Alessandra Raschkovsky, the Fed's removal of its flossing recommendation was dead wrong. "I can't understand why they did that," Raschkovsky told VICE. Raschkovsky said she'd observed cases in which flossing made no difference. "Some people are lucky. They have good genes, so they don't floss. But the majority needs to."

But the AP isn't the only entity to question the flossing doctrine. A 2011 piece of meta-analysis published by the Cochrane Database of Systematic Reviews also investigated flossing's efficacy by compiling data from 12 different trials. In the end, that team found "weak, very unreliable evidence from 10 studies that flossing plus toothbrushing may be associated with a small reduction in plaque at 1 and 3 months."

When pressed for proof of flossing's effectiveness, floss manufacturers Procter & Gamble and Johnson & Johnson both made questionable scientific claims, according to the AP. Johnson & Johnson simply claimed flossing fights plaque without backing it up at all, and the study Procter & Gamble used to defend itself had already been debunked by Cochrane's 2011 report.

But if that leaves you ready to repurpose your dental floss into a popcorn necklace or a prison garrote, you may want to keep shoving it in between your teeth for a couple reasons.

The Cochrane study may have dismissed most claims about dental floss regarding tooth decay, but it also adds that "the review showed that people who brush and floss regularly have less gum bleeding compared to toothbrushing alone." So if you don't like your gums to bleed, you might still want to make flossing a priority.

Raschkovsky told VICE she has personally observed a reduction in gum bleeding in patients who began a new flossing regimen. But the real difference, she said, came from the measurements of patients' unhealthily wide "gum pockets"—an indicator of gum disease.

"I've seen people with 6 millimeter pockets reduced to three—a big improvement," Raschkovsky said, adding, "and that was in people who had always brushed before, and then started flossing."

But Raschkovsky said that for the seriously floss-phobic, tools other than floss can produce a similar effect to classic flossing. "I have patients who refuse to floss," Rashkovsky said." They start using a Waterpik, and it's a tremendous difference."

And Water Pik, Inc.—the makers of Waterpik, a brand-name water-flossing tool—stands to benefit if Americans ditch their string. They've already been on the war path against regular floss since at least last September. In celebration of their product being added to ADA's page on healthy habits for people under 40, Water Pick, Inc. crowed that Americans should buy their device instead of floss. "[T]here is no evidence to support recommending string floss, with the possible exception to those who have perfectly healthy gums and can master string flossing at a very high level (and that's a very small group)," their advertisement claimed.

Still, despite the change in the federal guidelines, Raschkovsky plans to keep giving patients that classic dentist's bargain: Floss, or face a reprimand at your next visit. "Some people lie," she said, claiming that she can spot the difference between a flosser and a non-flosser.

But, she joked, "the gums don't lie."

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