Flossing Myth Debunked

Floss daily to prevent gum disease and cavities is something we have been told for years. However, there is little proof that flossing works.
The federal government, dental organizations, and manufacturers of floss have pushed the practice for decades. Dentists provide samples to their patients. The American Dental Association says on its website that, “Flossing is an essential part of taking care of your teeth and gums.”
During 2017, the Associated Press asked the departments of Health and Human Services and Agriculture for flossing efficacy evidence, and followed up with written requests under the Freedom of Information Act.
During 2018, the federal government issued its latest dietary guidelines and the flossing recommendation had been removed, without notice. In a letter to the AP, the government acknowledged the effectiveness of flossing had never been researched, as required.
The AP reviewed research conducted during the past ten years, focusing on twenty five studies that generally compared the use of a toothbrush with the combination of tooth-brushing and floss. The evidence for flossing is “weak, very unreliable,” of “very low” quality, and carries “a moderate to large potential for bias.” “The majority of available studies fail to demonstrate that flossing is generally effective in plaque removal,” according to one 2017 review. Another 2015 review cites “inconsistent/weak evidence” for flossing and a “lack of efficacy.” A 2011 study did credit floss with a slight reduction in gum inflammation, which can sometimes develop over time into full-fledged gum disease. However, the reviewers ranked the evidence as “very unreliable.” A commentary in a dental magazine stated that any benefit would be so minor it might not be noticed by users.
Two leading professional groups, the American Dental Association and the American Academy of Periodontology, for specialists in gum disease and implants cited other studies as proof of their claims that flossing prevents buildup of plaque, early gum inflammation called gingivitis, and tooth decay. However, most of these studies used outdated methods or tested few people. Some lasted only two weeks, far too brief for a cavity or dental disease to develop. One tested 25 people after only a single use of floss. Such research, like the reviewed studies, focused on warning signs like bleeding and inflammation, barely dealing with gum disease or cavities.
The president of the periodontists’ group, acknowledged the weak scientific evidence and the brief duration of many studies. When asked about the origins of his organization’s endorsement of flossing, he said it may simply have “taken the ADA’s lead.” When the ADA was asked for proof of its claim that flossing helps prevent early gum disease and cavities, the group cited the 2011 review and a 2008 two-week study that measured bacteria and did not consider gum disease. A spokesman for the dental association, acknowledged weak evidence, but he blamed research participants who did not floss correctly.
The global floss market is almost $2 billion, with half in the United States. The floss industry has paid for most studies and sometimes designed and conducted the research. Procter & Gamble, which claims that its floss fights plaque and gingivitis, pointed to a two-week study, which was discounted as irrelevant in the 2011 research review. Johnson & Johnson said floss helps remove plaque. When the AP sent it a list of contradicting studies, J&J declined comment.
Floss can occasionally cause harm. Careless flossing can damage gums, teeth and dental work. Though frequency is unclear, floss can dislodge bad bacteria that invade the bloodstream and cause dangerous infections, especially in people with weak immunity, according to the medical literature.


Generally dentists agree that there is a possibility that it works and are comfortable telling people to floss. It is interesting to note that, with two billion dollars at stake, no one is willing to actually do a real study and perhaps find that the king really has no clothes on. . .