Dental handpiece with a check valve

摘要

A dental handpiece has a coupling member in which a passage for delivering a coolant to a discharge nozzle at the head part is provided. In order to prevent a flow-back of contaminated fluid with bacteria past the handpiece, a check valve is provided and comprises a check valve member disposed in a recess that extends radially inward from an outer surface of the coupling member and receives a flexible portion for closing a portion of the passage. The flexible portion is such that when the fluid is turned off, a suction in the fluid line will cause the flexible member to be pressed against the base of the recess and to prevent dripping from the exit nozzle.