The device has a fixing element movable relative to a handle. A replacable interdental-treatment part (30) includes a treatment head (20) supported by a stem (32) made from a wire (33). The stem is fixed at the handle in a closed condition by a closing movement of the fixing element. The wire is bent at an end (34) of the stem in such a manner that the wire is guided over a section (36) of the stem in a dual manner, where the end is turned away from the treatment head. The wire is made up of steel, which contains carbon, silicon, sulfur, chromium, nitrogen, iron, manganese and nickel.
