The most surprising news in science this week may be that there's little good evidence to back up the claim that flossing is good for you.
Writing for the Associated Press, reporter Jeff Donn laid out a thorough case that the science of flossing just isn't there. And the best available research supports this point. However, broadly speaking, Donn found that dentists still think you should floss. Just because research hasn't been properly structured to show an effect, they told him, doesn't mean it's not there.
One of the most interesting points raised in the report is that many dentists think too many people floss incorrectly. Wayne Aldredge, president of the American Academy of Periodontology, told Donn that too many people floss like they're sawing between their teeth. Instead, he said, people should rub the floss up and down the sides of each tooth.
He suggests that more thorough studies designed to tease out the effect of proper flossing, particularly in folks most at risk of oral disease, might reveal an impact.
In the Tech Insider newsroom, all this flossing controversy sparked a second debate: If you're going to go ahead and keep flossing — something that still has a better chance of helping you than hurting you — should you floss before or after you brush?
I conducted an informal, un-scientific poll of our reporters and editors to get a sense of their flossing habits.
Out of 17 people who responded, five said they flossed before they brushed. Four said they flossed afterward. Eight, a plurality, said that the last time they brushed they didn't floss at all.
(Full disclosure: I've always been an floss-after-brushing person. Didn't even know before-brushing was a thing until today.)
The argument is fairly straightforward: Floss first, and you clear the way for the toothbrush to work between your teeth. Floss afterward and the plaque will already be loosened for you to scrape away.
Like the broader questions around flossing, it turns out there isn't a tremendous amount of published research one way or the other on this question. One 2015 study seemed to show that men who brushed before gained a statistically significant plaque control advantage, though women did not. (Worth noting: this study suffers from the same short-time-frame problems that plague much flossing research. The long-term effects are largely unknown.)
Many smaller dental groups cite the American Dental Association (ADA) as lightly recommending flossing first — though emphasizing that the most important thing is to floss regularly, not when you do it. The ADA currently does not recommend a particular order on their website. This seems to be the current consensus.