”Brush and floss twice a day to keep the cavities away.”
For decades, dentists around the globe have been reminding patients to floss their teeth every day.
It's been one of the most universal public health recommendations except there's little proof that flossing actually works.
In January, following an inquiry by the Associated Press asking for evidence that flossing was worthwhile,
the US Departments of Health and Human Services and Agriculture dropped flossing from their recommendations as part of US dietary guidelines.
Manufacturers often designed the studies and in some cases conducted the research.