Abstract: An elongated arched support member is provided including an elevated midportion an oppositely downwardly and endwise outwardly directed inclined end portions. A section of dental floss is provided and the lower ends of the end portions include structure which anchor opposite end portions of the section of dental floss relative thereto with said dental floss section in a tensioned state. The inner surfaces of the elongated member may engage and ride over the inner and outer side upper portions of adjacent teeth between which the section of floss is received as the arched member is oscillated lengthwise back and forth transversely of the associated gum ridge. The spacing between corresponding midportions of the floss support member and the floss section is at least generally equal to the vertical spacing between the crown surface of a tooth and the associated gum tissue.