Abstract: A device for cleaning teeth is disclosed as having a shaft for containing dental floss and floss holders. Wedge shaped fastening grooves in the floss holders hold the dental floss tightly between the floss holders. In operation, the segment of floss held between the floss holders is useable to clean between teeth.

Abstract: A method and an apparatus for measuring the wall thickness of a plastic article, particularly of a hollow rotation-symmetrical plastic article. According to the method, the wall of the plastic article is subjected to infra-red radiation and the intensity of, e.g., the continuously transmitted radiation is measured at preselected points, said intensity being a function of the wall thickness to be measured. At the same time, on one hand, the plastic article and, on the other hand, a radiation source and/or a radiation detector are set in an axial and rotational movement in relation to each other.