The debate began when the Associated Press published a piece calling into question the benefits of flossing. In doing so, it questioned one of the most universal recommendations for oral health: flossing to prevent tooth decay and gum disease.
Standards set by health authorities are supposed to be evidence-based. But the AP found little evidence that dental floss is effective. New federal guidelines released this month ( Dietary Guidelines) do not include flossing recommendations.
The absence of flossing recommendations goes against almost all oral health recommendations from dentists and hygienists, like: “Brush and floss your teeth twice a day, and see your dentist twice a year.”
For decades, dental professionals around the world have recommended flossing as a complement to brushing. As one phrase goes: “You do not need to floss all your teeth, only the ones you want to keep.” We all know that floss can help remove food stuck between our teeth. In addition, those of us who floss regularly know that flossing removes plaque and food that a toothbrush cannot reach.
So what is the controversy?
Federal guidelines require evidence from two group clinical trials. For flossing, this would require a comparison of one group of patients that flosses and a second group that does not. Then, over several years, researchers could see if the flossing group has fewer cavities and less gum disease.
The AP found a lack of such studies and unreliable data from those that were conducted.
Very few studies have looked at people who use floss at home, and those few studies show neither benefit nor harm. So the guidelines cannot make an “evidence-based” recommendation regarding flossing.
But, an absence of evidence doesn’t mean flossing is bad either. For instance, we do not need a clinical trial to prove that parachutes are beneficial. We also do not need a clinical trial to prove that food stuck between your teeth leads to trouble.
Even without formal evidence, the American Dental Association supports brushing and flossing and says it’s essential for oral health.
We know some people will benefit from flossing, while others may not. Some people may feel more comfortable after flossing, others may feel it’s a bother. Overall, there appear to be few risks related to flossing, but there’s no evidence for that either.
Therefore, our recommendation is to be practical: use common sense and keep your mouth clean with a toothbrush, toothpaste with fluoride and floss. You can also use mouthwash. After all, there is evidence that mouthwash works.
*Dr. Analia Veitz-Keenan is an associate professor of oral and maxillofacial pathology, radiology and medicine at NYU Dentistry. Dr. Richard Niederman is a professor and the chair of Epidemiology and Health Promotion at NYU Dentistry. For more information or to become a patient, visit the New York University College of Dentistry.