Abstract: A closure means for a bottle filled with a fluid comprises at least two closure disks that are each provided with at least one discharge opening at a common off-center position so that only in a singular relatively rotated position of these two disks a discharge of the bottled fluid will be made possible. This relatively rotated position is obtained by means of a fitting which may be fastened to the bottleneck through a turn-lock fastener and which has at least one discharge tube at a corresponding off-center position and interacting with the discharge opening of the one closure disk to rotate the same into the singular relative rotated position in which the discharge tube as well will be axially aligned with the discharge openings of the two closure disks. A third closure disk is preferably provided for presenting with a concentric guiding slot a first working element of a bayonet-type fastener the second working element of which is presented by the head portion of a coordinated discharge tube of a fitting.

Abstract: A nozzle head for the hand piece of a dental prophylactic apparatus comprises a connector having two members that are centered with respect to each other along an axis that is in common with the connecting end of an inner tube with a supply line for an abrasive powder material in mixture with air under pressure and also in common with the connecting end of an outer tube as fixed to the same connector member with a supply line for water under pressure through a transverse bore extending between the two connector members, the inner and outer tubes forming first and second orifices that preferably open towards a cup-shaped hollow space formed by a coaxially arranged circular collar.