Abstract: The present invention is directed to a dental handpiece having two parts which are coupled together for relative rotation on the axis of the dental handpiece characterized by an arrangement for conveying light through the handpiece and including a rotatable optical coupling having at least one transmission ring.

Abstract: A dental handpiece having a first section rotatably mounted on an axis of a drive motor part and supporting a head part at the other end, characterized by the head part being releasably connected to the first section and a rotatable coupling in the cooling lines between the drive motor part and the first section being free from uncoupling when changing the head part to change the drive ratio of the drive train. In addition, the head part has a protective sleeve which surrounds the first section and the rotatable coupling so that the rotatable coupling and first section are not subjected to sterilization with adverse effects to the coupling and to the condition of the lubricant in the various bearings in the drive train.