A close up of mouth and dental floss in a white background.

Do I Need to Floss?

Recent reports in newspapers, including the New York Times, have suggested that there is little-to-no use in flossing. So that begs the question: Do you need to floss? The answer is YES. Cleaning between your teeth is essential to dental hygiene. It’s time to find out how these reports came to be — and why flossing your teeth is important.

Research Into Dental Care

Scientists use a system called Systematic Review and Meta Analysis to find the answers to dental and medical questions. This method explores and summarizes previous research on a particular topic, which informs health care providers and the public.

The most important research for systematic reviews is the Randomized Clinical Trial (RCT). This is perhaps the most powerful method of health care research. The results of a large, carefully conducted RCT can help provide answers to important health care questions. When there are several RCTs on the same topic, scientists are able to glean the results from these studies, and then combine them into a single summary publication: the Systematic Review and Meta Analysis. The leading scientific organization that oversees the quality of these systematic reviews is the Cochrane Collaboration.

A recent Systematic Review, conducted by members of the Cochrane Collaboration, evaluated the published clinical trial evidence on the quality of brushing and flossing—versus brushing alone. The scientists used research from 12 clinical trials. They were interested in the results from the gingival and plaque index. The gingival index gives a numeric term to the state of the visually evident gum disease’s associated redness and bleeding. The plaque index measures the amount of plaque or tarter present on the teeth.

The Results of the Study — and Whether You Should Floss

The answer to whether brushing plus flossing is better than brushing alone was an unequivocal yes. They determined that flossing, in addition to brushing, is superior at reducing signs of gingival inflammation. As for plaque index, the results were also in favor of flossing, but to a lesser degree.

You might be wondering, “Why did newspapers call into question the need to floss, especially if the results proved that flossing reduces gum inflammation and plaque on the teeth?”

Apparently it’s because of the small improvement of the plague index for flossing, versus not flossing. However, the plaque index is not efficient at measuring the presence of plaque between the teeth. So, it would not be expected that flossing would reduce plaque index over that of brushing alone.

Another important point: the presence of plaque does not indicate disease. Plaque contains bacteria that cause gum disease, but not everyone with plaque will get gum disease. In fact, plaque or the plaque index is a poor indicator of gum disease, while the gingival index is the gold standard clinical measurement for gingival inflammation. Gingival inflammation, as measured by the gingival index, is an indicator of the disease gingivitis.

So, if you wish to reduce the signs of gingival inflammation and bleeding, flossing and brushing are the way to go.


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