The device for infiltration of approximal tooth surfaces, with a flexibleplanar element and with a holder into whichthe planar element is clamped, is characterized in that the planar element(14) is a liquid-impermeable plastic film (14) which has asurface area (22) for taking up a liquid to be used for treatment, and in thatthe holder is a bow-shaped element (12) with a web (16)and two lateral arms (18) which extend from the latter and are arranged in anarc-shape or U-shape, to which the plastic film (14) isconnected in a liquid-impermeable manner.
