Med thumb floss

Flossing might be the most burdensome part of the getting-ready-for-bed process. First you cut off a piece of string. Then you pull it taut, shove it between your chompers and saw at your gums back and forth, incisors to wise teeth, top and bottom. It's bloody. It's painful. It's a time-suck. And, according to an investigation by the AP, it's also largely unnecessary.

Does that mean we've been suckered into the annoying ritual (or losing sleep over guilt from skipping it) since at least 1908, when the American Dental Association (ADA) began promoting floss as a universal must-do? What's next? A reveal about the pointlessness of mascara removal? Will the NIH laude birthday-cake remix ice cream as a superfood? Well, we can dream, and until then, we can learn more about floss-gate.

The AP analyzed "the most rigorous research conducted over the past decade, focusing on 25 studies that generally compared the use of a toothbrush with the combination of toothbrushes and floss." They found scant evidence that flossing does much to remove plaque, stanch gum inflammation or prevent tooth decay. While the powers-that-be in dentistry, the American Dental Association and the American Academy of Periondontology, cited research to support their pro-flossing position, the AP dismisses the cited studies as flawed. In one case, for example, study findings hinged on a single flossing session. 

The AP story quotes dental experts who acknowledge the absence of pro-flossing evidence but nonetheless resist rejecting the oral-hygeine ritual. One ADA member, the AP reported, blamed the so-so research on participants' flossing deficiencies. Ultimately, the AP depicts floss-or-rot fear-mongering as a boon to dental industry stakeholders rather than a necessary (or even necessarily useful) health practice. 

Before ceremoniously ditching floss, we figured we'd see what dentists have to say, given the years of shame we've endured for flossing without sufficient zeal. Some dentists are apparently well-aware of the great floss sham. Others, though shocked at first, concede that evidence for flossing is thinner than they realized. Nonetheless, the dentists we surveyed see value in the twice-daily chore.


Just because there's no evidence that floss is effective doesn't mean that floss isn't effective

It's no secret to many in the dental public health community that the evidence for flossing as an efficacious method of preventing proximal caries and chronic periodontitis is sparse and of low quality. But there are some valid reasons for that situation: One: Well-conducted randomized controlled trials would be very expensive, and I highly doubt major funders of biomedical research would be interested in spending the millions of dollars it would take to conduct such large, long-term studies in which compliance will be difficult to monitor. Two, given the tradition of flossing that has been promoted for many decades, there would be serious challenges (including ethical issues) to randomizing someone to not flossing for the next 3-5 years.

Personally, I would not want to participate in such a study. One principle worth bearing in mind is that absence of evidence of effectiveness is not at all equivalent to evidence of absence of effectiveness. It then comes down to weighing the probable risks and benefits, and flossing is a low-cost, low-risk behavior compared with the known and probable benefits. I intend to continue to floss my teeth and recommend others do as well.  

— Scott Tomar, professor at The University of Florida College of Dentistry

"I will not change how I recommend at-home oral care."

I am very shocked at the statements released yesterday. However, when I think back to the studies I have read, and learned about, there's a lack of depth to their research. With that said, I also know first-hand what flossing can do to help prevent cavities, gingivitis and potentially periodontitis. 

I think we've placed to much stock into flossing alone, and forgotten about other factors such as genetics, medication and diet. Again, this is based off of observations not research, but I have many patients who floss and floss and floss, and it shows via their gingival health, but they still have interproximal (between teeth) decay. To the contrary, many people don't /won't floss and are fine. 

In my opinion, [flossing] can make a difference in fighting cavities in the right oral environment/patient. In others it won't make a difference...shhh! With that said, in regards to gingivitis, and therefore periodontitis, when done correctly flossing removes the bacteria/plaque that cause inflammation. I will not change how I recommend at-home oral care. People struggle as it is, so if I give them any slack on at home care then who knows how bad it'll get. 

— Lee Hartzle, dentist in Wooster, Ohio

Don't be silly. Flossing won't undo your vices.

Never tell a patient that floss will protect against sugar or tobacco — the two prime causes of dental morbidity. One can floss for all kind of reasons, ie, removing an annoying piece of meat, making sure there is no broccoli between the teeth on a first date, etc. But don't be seduced into eating sugar or picking up smoking under the impression that flossing will be an antidote — there is no good evidence in support of that belief.

— Philippe Hujoel, University of Washington School of Dentistry

The evidence for flossing is weak, but that doesn't mean we should hang up the tape. 

The evidence for flossing as an effective method in preventing interproximal dental decay or gum diseases is weak, not consistent and of low quality. This does not mean flossing is not effective or a good smart habit. It means we do not have enough good credible data and published studies to state 100 percent that it is effective in preventing dental diseases.

ADA states that to maintain good oral health, brushing for two minutes, twice a day with a fluoride toothpaste, cleaning between teeth once a day with an interdental cleaner and regular dental visits advised by your dentist is important to keep mouth healthy. Whether the interdental cleaner is floss, interdental brush, oral irrigator or any other method, can be left between the individual patient and a dentist or other oral health professional.

— Jaana Gold, professor at University of Florida College of Dentistry and Still University