> "It's low risk, low cost," National Institutes of Health dentist Tim Iafolla told CNBC. Isn't risk something that should be determined by study? I can think

> "It's low risk, low cost," National Institutes of Health dentist Tim Iafolla told CNBC. Isn't risk something that should be determined by study? I can think of a couple ways that flossing may actually damage a mouth.