Abstract: An air-driven dental instrument (10) includes a replaceable vibrator module (16) detachably accommodated in an axial lodgment defined by an elongated outer casing (14) comprised of a frontal cap (22A) and a main body (26A) coupled with each other. When the cap (22A) is coupled, the module (16) is axially positioned against the cap (22A) by a positioning sleeve (90A) and is rotationally locked against the sleeve (90A) by a hexagonal formation (128) engaging into cutouts (136) formed on a housing (134). When the cap (22A) is disconnected from the main body (26A), the module (16) is retained by the housing (134) but is partly exposed therefrom. This permits a user to grip the module to thereby facilitate replacement of the module (16).

Abstract: The air-driven vibrator (10) includes a disc-shaped vibratory element (40) movably received in a disc-shaped working chamber (38). Upon injecting air jets into the chamber (38) through tangential injection ports (46), the element (40) is rotated and oscillated to generate vibration. The feature of the vibrator is that inwardly directed projections (66, 72) are provided on the inner end faces (34, 36) of the chamber (38) to prevent the element (40) from sticking to the end faces (34,36) when the vibrator is not in use. Due to the provision for the projections (66, 72), the edge of the element (40) need not be chamfered. This enables mass production of the elements (40) and increases the production yield of the elements (40).

Abstract: An air-driven dental scaler (10) having a scaler tip (78) oscillated by an air-driven vibrator (22) of the class wherein a disk-like rotor (40) is rotated within a disk-shaped chamber (38) to impart vibration to a vibrator body (26). In order to suppress or reduce annoying audible sound issued during operation of the dental scaler (10), the vibrator (22) is positioned immediately adjacent the distal end (24) of the casing (12) and the scaler tip (78) is directly mounted to the vibrator body (26), with the scaler tip (78) being unsupported by and vibrationally isolated from the casing (12) to enable the scaler tip (78) to oscillate without interference by the casing (12). This arrangement enables the frequency of vibration of the vibrating system (22/78) to increase to near the ultrasonic frequency range while retaining the full scaling capability of the dental scaler (10).

Abstract: An endodontic irrigating instrument comprises a handpiece having an internal liquid passage therethrough extending from a liquid inlet formed in the proximal end of the handpiece to a liquid ejection nozzle provided at the distal end. The handpiece incorporates a suction or vacuum pump of the airjet or ejector type which comprises an air nozzle connected by a passage with an air inlet formed also in the proximal end of the handpiece. The vacuum chamber of the suction pump is connected by a separate internal passage in the handpiece with an aspiration needle provided adjacent to the liquid ejection nozzle. The proximal end of the handpiece is designed to be fitted with a coupling joint attached to a multiple-channel flexible hose which is conventionally used to supply compressed air and pressurized water from a dental unit to conventional air-driven dental turbine tools. Thus, the endodontic irrigating instrument can be used interchangeably with existing turbine tools.

Abstract: An air-driven dental scaler is provided with a vibrator assembly which comprises a rigid vibrator body having an inner disk-like chamber in which a disk-like rotor is received with a small gap between it and the chamber. The vibrator body is provided with a plurality of inlet ports which are arranged in such a manner that a jet of air impinges upon the cylindrical outer surface of the rotor in a substantially tangential direction to cause the rotor to rotate. As the rotor rotates, it strikes or rolls on the side walls of the chamber to impart a vibratory movement to the vibrator body, which movement is transmitted through a shaft to a scaler tip. The air leaves the chamber through an exhaust port provided, preferably, in one of the side walls of the chamber. The rotor is, preferably, provided with a central opening to enhance the exhaust efficiency.