Dental organizations and the federal government have long urged people to use dental floss, but the latest US guidelines have dropped the recommendation
It’s one of the most universal recommendations in all of public health: floss daily to prevent gum disease and cavities.
Except there’s little proof that flossing works.
Still, the US federal government, dental organizations and manufacturers of floss have pushed the practice for decades. Dentists provide samples to their patients; the American Dental Association insists on its website: “Flossing is an essential part of taking care of your teeth and gums.”
Everything you ever wanted to know about teeth (but were afraid to ask the dentist)
The federal government has recommended flossing since 1979, first in a surgeon general’s report and later in the Dietary Guidelines for Americans, issued every five years. The guidelines must be based on scientific evidence, under the law.
Last year, the Associated Press asked the health and agriculture departments for their evidence, and followed up with written requests under the Freedom of Information Act.
When the federal government issued its latest dietary guidelines this year, 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 looked at the most rigorous research conducted over the past decade, focusing on 25 studies that generally compared the use of a toothbrush with the combination of toothbrushes and floss. The findings? The evidence for flossing is “weak, very unreliable”, of “very low” quality, and carries “a moderate to large potential for bias”.