Flossing isn’t exactly what you want to be doing right before going to bed, but many of us are advised by our dentists to keep up the habit.
Some dentists have even told their patients that although flossing once a day and brushing your teeth twice a day is essential for proper dental hygiene, they’d rather skip out on brushing in favor of flossing.
The American Government has been a long supporter of flossing, mentioning it in the Dietary Guidelines for Americans since 1979. However, the 2016 guidelines no longer recommend the habit (1,2).
How it All Began
After being tipped off about the inefficacy of flossing by his son’s orthodontist, Jeff Donn, a national writer for The Associated Press and 2012 Pulitzer finalist began extensively researching whether or not this cleaning process had any real positive impact on dental health (3). In doing so, he effectively changed governmental guidelines.
Growing more suspicious about the orthodontist’s tip, he revisited the 2010 dietary guidelines, which clearly stated: “A combined approach of reducing the amount of time sugars and starches are in the mouth, drinking fluoridated water, and brushing and flossing teeth, is the most effective way to reduce dental caries.” (4).
Curious about this claim, Donn examined 25 studies on the subject with surprising results. All the 25 documents he read through concluded that there was “very low” quality proof that flossing works.
One review included 12 case-controlled trials following a total of 1083 participants. The researchers found “weak, very unreliable evidence” to support the claim that the addition of flossing to a regular brushing routine had any significant benefits in preventing plaque and gingivitis. Experts also brought to light the “a moderate to large potential for bias.” of some of the studies in favor of flossing (5).
After coming up short in his research, Donn filed an FOIA (Freedom of Information Act) request to the Department of Agriculture and Health and Human Services, which issues the Dietary guidelines every 5 years. By law, these guidelines must be based on scientific evidence and the department must supply proof to any citizen curious about their claims (6).
Donn waited 6 months for a reply. Finally, the new guidelines for 2016 went public and any mention of flossing was quietly deleted from the guide. The next day, Donn received the answer he had been waiting for. It turns out that officials had never fully researched the effects of daily flossing before coaxing Americans into the habit. Quite simply, they never questioned that flossing could be anything but beneficial.
The American Academy of Periodontology acknowledged that much of the current research in favor of flossing isn’t viable because it doesn’t take into account a large enough population or a long enough study period. In fact, most studies only examine participants for 1-3 months, some ending after only one flossing session.
It can take years for gum disease and cavities to develop, meaning that lengthy studies are necessary to truly understand the impact of daily flossing. It’s also worth noting that part of the lack of evidence in favor of flossing may be due to participants flossing incorrectly.
Despite recent criticism in regards to the government’s support of flossing and the current lack of evidence in favor of the practice, the U.S. Department of Health and Human Services has issued a statement reaffirming flossing as “an important oral hygiene practice” (7).
Flossing is a Big Business
Flossing first came into the mainstream in the early 19th century, but the practice dates back hundreds of years. It wasn’t until 1882 that silk floss became the tool of choice for getting pesky food out of your teeth (8).
Nowadays, flossing has become a $2 billion-dollar-a-year industry. Some researchers have suggested that dental floss companies have funded and even conducted studies in favor of the use of floss to boost their sales, adding to the current bias in favor of flossing (9).
So Why Floss?
Flossing isn’t just about removing gunk between your teeth, it’s also meant to dislodge plaque (10).
Plaque is an invisible layer of bacteria that coats your teeth every day. Brushing removes most of the plaque on your teeth, but your toothbrush can’t remove it all. “If you don’t floss, you are missing more than one-third of your tooth surface.”, insists the Canadian Dental Association (CDA).
According to the CDA, it takes between 24 to 36 hours for plaque to harden and become tartar. Once hard, the build-up can only be removed by dental professionals.
Tartar build-up causes gum inflammation (gingivitis) and a string of other health problems. “Gum inflammation progresses to periodontitis, which is bone loss [tooth loss], so the logic is if we can reduce gingivitis, we’ll reduce the progression to bone loss,” explains Dr. Sebastian G. Ciancio, the chairman of the department of periodontology at the University at Buffalo. It can take 20 years for periodontitis to develop, meaning that the benefits of flossing aren’t obvious short-term.
Wayne Aldredge, president of the Periodontists’ Group adds that certain patients are more prone to gum disease and may experience the onset of the disease much quicker, including diabetics and smokers. Gum disease is also linked to kidney disease, diabetes, and heart disease.
It’s important to note that not all evidence discredits the value of flossing. The New York Times noted that a review of six trials examining the effect of flossing on children found that 5 days of proper flossing a week for two years resulted in a 40% reduction in the risk of cavities.
If you’re still on the fence about whether or not you should floss, here’s what the experts think.
Dr. Romanita Ghilzon, an associate professor in the dental faculty at the University of Toronto says: “I would say if you know how to floss I would continue just in case it does make a difference”.
Fellow Canadian Dr. Larry Levin, vice-president of the Canadian Dental Association, told CBC that his 40 years experience can attest to the benefits of flossing.”
“Floss is the only material that will fit right in between two tight teeth and it will go in between to clean them.”
Tim Iafolla, a dentist at the U.S. National Institutes of Health insists that flossing is a “low-risk, low-cost” habit. On the subject of recommending the use of floss, he had this to say: “We know there’s a possibility that it works, so we feel comfortable telling people to go ahead and do it.”
Lastly, the President of the American Academy of Periodontology, Dr. Aldredge, highly recommends flossing to his patients as an easy way to avoid problems down the road. “You don’t know if you’ll develop periodontal disease, and you can find out too late [to reverse it],” he warns.
Still Want to Floss? Here’s How You do It
Flossing incorrectly can leave you with gum and tooth damage, so it’s important to take the time to do it right. Worse yet, flossing too violently can cause tears in the gums through which bacteria may enter the bloodstream and cause an infection.
To begin, tear off about 18 inches of floss and wrap it the end around the middle finger of one hand. Grab the other end of the floss and wrap it around the middle finger of your opposite hand. Pinch the floss between the thumb and index finger of each hand and gently rub it between your teeth towards your gum line.
As it reaches the gums, reposition your fingers to create a “c” shape around the left tooth, holding it firmly. Carefully move the floss up and down under the gums. Repeat with the right tooth and continue the process with all your teeth, using fresh sections of floss for each tooth. Avoid swallowing throughout the process and gargle salt water afterward to prevent ingesting the bacteria you’ve dislodged.