A dental flosser (2) comprising a tensioning structure (8, 10, 12) for holding a section of a dental floss for flossing. The dental floss (14) is of continuous length and has on said length a plurality of spaced nodes (30) defining a plurality of sections. The tensioning structure is arranged to apply a tensioning action to a pair of nodes on said length to tension the section (14) defined by the pair. The tensioning structure is so arranged so that the section is replaceable with another one of the sections (14b). A method of operating a dental flosser comprises a) operating the dental flosser to at least partially remove a tensioning action acting on each of the pairs of nodes of the section to tension the section, b) removing the section from the position and locating the other section in the position, and c) applying a tensioning action to the pair of nodes defining the other section.
