An article in Forbes tries to argue that there’s scientific literature supporting the idea that you don’t need to floss. The author is not without his bias, as he clearly has had some traumatic experiences at the dentist. I constantly get feedback that our hygienists are among the gentlest, while giving your teeth a great cleaning.
The author tries to go through different science articles that look to examine the benefits of flossing.
The first, published in 2006, narrowed its focus to the effects of flossing in young children between the ages of four and thirteen. The reviewers found that children who had their teeth flossed by a professional hygienist five days per week for 1.7 years had a 40% decreased risk of cavities. However, those who were trained to floss and carried it out themselves did not enjoy any reduction.
This is a great study to show you just how important flossing is. Even the author admits that flossing results in a 40% reduction in cavities in primary teeth. That’s huge! The problem is that children flossing for themselves (instead of by a professional) did not see those benefits. The message here is not that flossing provides no benefit, but that we need to better educate children (and their parents) on their flossing technique.
The second study is a Cochrane review, a type of review which only looks at a very specific subset of evidence. Moreover, they only looked at the benefits on plaque and gingivitis, which are important parameters, but didn’t look to see if there was an improvement on cavities. Even though the authors did find that flossing provided a benefit, they ultimately concluded against recommending it.
Among the types of studies that a Cochrane review will not look at are twin studies. These are studies where they compare genetically identical studies of twins and compare those who floss to those who don’t. One such study showed that flossing significantly decreased the bacteria that cause periodontal disease and dental caries, but was not carried on long enough to show the benefits on long term periodontal health.
A third review of flossing, published in 2012, showed that flossing provided a small but significant reduction in gingivitis and weaker evidence for reduction in plaque build up compared to brushing alone. This review did not look at other important benefits of flossing such as decay, tartar build up or clinical attachment (an indicator of periodontal disease). It did, however supports earlier work which has shown:
The toothbrushing only group achieved a 35% reduction in bleeding sites and the three flossing groups all demonstrated reductions of about 67%.
Bleeding is a marker of inflammation and a sign of gingivitis. Once again, the study shows that brushing alone is not as effective as brushing and flossing in preventing gingivitis.
Finally, even the author agrees that one of the biggest problems with getting the benefits from flossing is technique.
One plausible explanation for the dearth of supporting evidence for flossing is that we’re all doing it incorrectly. Most flossers simply insert the string in between their teeth, yank out a few bits of food, and assume they’re done. They’re not. The American Dental Association recommends curving the floss into a “C” shape against the side of every tooth and firmly, but carefully, motioning it up and down.
And that’s something I can agree with. It’s good idea to demonstrate your flossing technique when you visit the dentist.