A mold (70) for forming a single-use dental floss holder containing a piece of dental floss comprising an applied wax composition, said mold comprising: a first part (90) comprising a first cavity (100) arranged inside, said first cavity being defined by a lower base surface (100e) and a peripheral side wall (100d), said first cavity comprising a base part (100a) and first (100b) and second (100c) portions separated from each other that have proximal sections (100h, 100i) and distal sections (100j, 100k), and extend from said base part, a second part (80) comprising a second cavity (110) disposed therein, being defined said second cavity by a lower base surface (110e) and a peripheral side wall (110d), said second cavity comprising a base part (110a) and first (110b) and second (110c) portions separated from each other having proximal sections (110 h, 110i) and distal (110j, 110k), said rear portions extending from said base part and ending at said distal section； and a slot (114) having first (114a) and second (114b) terminal sections and a middle section (114c), said slot extending over the entire width of said second part, said first and second terminal sections of said transverse slot being and coinciding with said distal section of said first and second spaced parts, respectively, said groove having an aspect ratio (width: depth) of 10: 1 or greater.Un molde (70) para formar un soporte de hilo dental de un solo uso que contiene un trozo de hilo dental que comprende una composición de cera aplicada, comprendiendo dicho molde: una primera parte (90) que comprende una primera cavidad (100) dispuesta en su interior, estando dicha primera cavidad definida por una superficie de base inferior (100e) y una pared lateral periférica (100d), comprendiendo dicha primera cavidad, una parte de base (100a) y porciones primera (100b) y segunda (100c) separadas entre sí que tienen secciones proximales (100h, 100i) y distales (100j, 100k), y se extienden desde dicha parte de bas
