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Those regularly chided by their dentists got good news on Tuesday, as the U.S. government acknowledged something to which TIME had brought attention last year: there is little scientific evidence that flossing your teeth really makes a difference when it comes to cavities and gum disease.

But if we’ve all just been wasting minutes a day on flossing—which, let’s be honest, few people actually want to do—why did we start doing that in the first place?

Humans have surely been using string (among other tools) to dislodge food for as long as string has been around, but the modern idea of dental floss is only two centuries old. In 1819, Levi Spear Parmly of New Orleans published his book A Practical Guide to the Management of the Teeth, and in it he described an invention he is often credited with thinking up just a few years earlier:

Furthermore, Parmly specified, “particular care [should be] taken to pass the waxed silk in the interstices, and round the necks of the teeth.”

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Within a century, Parmly’s idea had become dental common practice, with inventors working on improvements. When World War II hit American silk supplies hard, a new invention—nylon—stepped in, thanks in particular to a pioneering dentist names Charles C. Bass.

In June of 1910, a New York business had this to say to the readers of Practical Druggist and Pharmaceutical Review of Reviews: “You know the value of dental floss. No one realizes better than you that the constant use of it would save lots of tooth trouble.” Today, however, “the value of dental floss” is not so certain.

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