In the 1870s, Asahel Shurtleff helped to civilize floss when he patented the first dispenser: a bobbin of thread with a U-shaped prong sticking out of its side. The prong worked like a tiny metal hand, guiding floss between the teeth. His invention anticipated the portable floss holders you can now buy in drugstores.

Designers have since given us bubble-gum-flavored floss, Gore-Tex strands and tooth-shaped dispensers — all in an attempt to make flossing seem fun or at least not too difficult. Recent studies, meanwhile, have revealed that flossing might be one of the simplest ways to ward off tooth decay.