Abstract: The present invention provides a maintenance apparatus for increasing the service life of a medical handpiece. The maintenance apparatus is provided with a first fluid supply which feeds a maintenance fluid to the bearings of a handpiece, capable of rotatably supporting a rotary tool, and a second fluid supply which feeds the maintenance fluid to the chucking structure of the handpiece, capable of detachably holding the rotary tool.

Abstract: A light emitting device is provided in a dental handpiece device for illuminating an area in the vicinity of a dental care tool at a tip of the dental handpiece device. The light emitting device includes a light emitting section including a light emitting diode element and an electrode, and an electric power control section for controlling electric power to be supplied to the light emitting diode element via the electrode. The electric power control section includes an electric current restriction element for restricting an amount of electric current to be supplied to the light emitting diode element, and a reverse voltage prevention element for preventing a reverse voltage from being applied to the light emitting diode element.

Abstract: The present invention provides a maintenance apparatus for increasing the service life of a medical handpiece. The maintenance apparatus is provided with a first fluid supply which feeds a maintenance fluid to the bearings of a handpiece, capable of rotatably supporting a rotary tool, and a second fluid supply which feeds the maintenance fluid to the chucking structure of the handpiece, capable of detachably holding the rotary tool.

Abstract: An air turbine handpiece comprises a grip portion and a head portion disposed at a tip of the grip portion. In the handpiece, a rotor is disposed in a chamber in the head portion, and a cutting tool is detachably attached to a rotation shaft which is rotated integrally with the rotor. A nozzle opening for injecting air toward a turbine blade portion and an exhaust opening for exhausting the injected air to the outside are opened to the chamber of the head portion. An arc width of the nozzle opening in a circumferential direction is two or more times a height in a direction of a rotation axis of the rotor. The nozzle opening is formed so as to extend in a width direction.

Abstract: A dental cutting tool holder which prevents the occurrence of sliding between the cutting tool and collet chuck at high-speed rotation, and prevents dislocation of the cutting tool securely, comprising a collet chuck into which a dental cutting tool is inserted detachably, and which comprises a right cylindrical section and a plurality of arc-section segments which are contiguous to the cylindrical section and divided in a circumferential direction; a rotor into which the collet chuck is inserted, and which is driven for rotation around the axis of rotation together with the collet chuck; and a clamping member which intervenes between the collet chuck and the rotor to press the respective segments inward in a radial direction by its displacement toward one end of the axis relative to the collet chuck while releasing the inward, radially pressed condition by its displacement toward the other end of the axis. The respective segments are formed with recess sections and an axially extending protrusion section.