<P> Despite the availability of a number of interdental cleaning aids, dental floss has received the most attention, although it can be challenging to use as it requires a high level of dexterity, resulting in less use . </P> <P> It has been widely accepted that the use of floss has a favourable effect on plaque removal and disease prevention and the American Dental Association reports that up to 80% of plaque can be eliminated with this method . Several reviews, however, have failed to find any clear benefit over toothbrushing alone . </P> <P> Levi Spear Parmly, a dentist from New Orleans, is credited with inventing the first form of dental floss . In 1819, he recommended running a waxen silk thread "through the interstices of the teeth, between their necks and the arches of the gum, to dislodge that irritating matter which no brush can remove and which is the real source of disease ." He considered this the most important part of oral care . Floss was not commercially available until 1882, when the Codman and Shurtleft company started producing unwaxed silk floss . In 1898, the Johnson & Johnson Corporation received the first patent for dental floss that was made from the same silk material used by doctors for silk stitches . </P> <P> One of the earliest depictions of the use of dental floss in literary fiction is found in James Joyce's famous novel Ulysses (serialized 1918--1920), but the adoption of floss was low before World War II . Physician Charles C. Bass developed nylon floss during World War II . Nylon floss was found to be better than silk because of its greater abrasion resistance and because it could be produced in great lengths and at various sizes . </P>

When did dental floss come on the market