Abstract: The specification discloses an improved dental cuspidor having a vacuum drain means. The specification also discloses a drain having a drain chamber of which one side is formed by a diaphragm so that when water reaches a given height in the chamber, the diaphragm actuates an air valve to drive a piston to open a drain valve to a vacuum drain.

Abstract: The specification discloses a dental handpiece having a handle and a plurality of fluid tubes extending from the rearward end of the handle to the forward end of the handle. The handpiece has a coupling for connecting the rearward end of the handle to a plurality of fluid supply hoses so that each hose can deliver fluid to a corresponding one of the tubes while permitting the handle to be rotated relative to the hoses. The coupling includes a cylindrical bushing secured in the rearward end of the handle and a cylindrical connector adapted to be slidably inserted into the bushing to define an interface therebetween. The bushing and the connector having a plurality of pairs of corresponding passages. At least one passage of each pair opens in an annular groove at the interface which is contiguous with the opening of the other passage of the pair at the interface. The coupling includes a plurality of O-rings for sealing the fluid connections.

Abstract: The specification discloses a dental syringe with a tubular handle adapted to pre-heat water before it is delivered through the syringe tip into a patient's mouth. Water and air supply hoses are connected to the handle, and electric heater and thermostat elements are mounted within the handle for maintaining the temperature of the water therein at from about 95.degree. F. to about 105.degree. F.

Abstract: The specification discloses a dental syringe having a head, a tip and a releasable coupling mounted on the head. The head and tip have a corresponding number of fluid passages therethrough. The coupling includes a cylindrical base and a lock nut which screws over the base. The base and the lock nut define an axially extending bore which communicates with the passages through the head and removably receives the rearward portion of the tip. An elastomeric O-ring is positioned between the base and the lock nut and surrounds the bore. When the rearward portion of the tip is fully inserted in the bore the O-ring seats in a groove surrounding the rearward portion of the tip. When the lock nut is fully screwed over the base, deformation of the O-ring is substantially prevented and the tip cannot be withdrawn or ejected from the coupling.