1. An assembly of dental floss holders, where each holder comprises a strand of dental floss having opposite first and second ends and a pair of first and second plastic gripping elements respectively secured to each of said ends, said assembly comprising a plurality of said holders situated in spaced parallel relationship, the strand and gripping elements of each holder extending axially in a generally straight line, each of said first gripping elements being joined to other first gripping elements immediately adjacent thereto, each of said second gripping elements being joined to other second gripping elements immediately adjacent thereto, said assembly further comprising at least one generally stiff first support means having a body part and opposite ends, said support means situated generally parallel to the strand of one of said holders with said ends of said support joined to said first and second gripping elements respectively, whereby said first support means maintains said first gripping elements spaced apart from said second gripping elements of each pair respectively and maintains said strand between each pair of first and second gripping elements generally straight, each holder being separable from an adjacent holder by breaking off one gripping element relative to the adjacent gripping element joined to said one gripping element.