An electric dental handpiece including a head engaging a handle and configured to rotatably support a tool. The handle includes a lower handle portion and an upper handle portion with the lower handle portion engaging the head and the upper handle portion having an attachment area configured for attachment to a power supply. An electric motor is positioned with a majority thereof within the lower handle portion and is configured to rotate the tool.

A dental preparation instrument having a pneumatic turbine (1) with a rotor (5) for driving a tool (1.1), wherein the rotor (5), which is mounted in a turbine chamber (18) for rotation about an axis of rotation (4), is impinged by compressed air from a compressed-air nozzle (22). A first radial partition (23) has an opening (17) via which an annular space (8) is in flow connection with an outlet duct (19).

A dental tool comprises a guard having a concave inner surface at one end and an adapter. The adapter comprising a nose, a monolithic ball portion having an integral neck, and a ball receiver comprising a convex outer surface and a concave inner surface, where the concave inner surface of the ball receiver engages a convex outer surface of the monolithic ball portion, the concave inner surface of the guard engages the convex outer surface of the ball receiver, and an opposite end of the guard rests upon the nose.

A medical or dental handpiece has a grip. The grip includes first to third rotation shafts. The first and second shafts are connected through a first gear mechanism and the second and third shafts are connected through a second gear mechanism so that a rotation is transmitted from the first shaft through the first gear mechanism to the second shaft and then from the second shaft through the second gear mechanism to the third shaft. The first or second gear mechanism has an internal gear secured on one shaft and an external gear secured on the other shaft, the internal and the external gears being engaged with each other. The external gear is substantially enclosed within a cylindrical plane extending along a peripheral edge of the internal gear.

A root canal therapy device with a mechanical vibration mode and a rotation drive mode includes a head, a handle, a first flexible drive shaft and a second flexible drive shaft. The head includes an outer main part, a mandrel part for mounting a root canal file, a first drive input shaft part and a second drive input shaft part. The mandrel part is mounted in the outer main part. A first drive motor and a second drive motor are disposed on the handle. The invention has the following beneficial effects: the root canal file can rotate and vibrate during root canal preparation, so that the wall of a root canal is efficiently cut by the file; and the file can also vibrate, so that cutting resistance and cutting temperature are effectively reduced, a smear layer is avoided, and the quality and efficiency of root canal preparation are improved.

A hand-held gripping device that allows one of a surgeon, a dentist, and an orthodontist to reach interior portions of a person's anatomy, includes a gripping portion having a pair of jaws movable relative to each other between fully clamped and fully opened positions thereof, a handle portion spaced apart from the jaw portion by a bendable central portion that has a hollow, bendable corrugated with at least one cord extending therethrough.

Disclosed is a rotatable ultrasonic vibration device. The ultrasonic vibration device includes: a shell; a hollow locking rod having a center hole; a piezoelectric transducer surrounding the hollow locking rod; a first amplitude-change pole mounted in the center hole, one end of the first amplitude-change pole being fixedly connected to the hollow locking rod, and at least a portion of the length of the first amplitude-change pole being located in the space surrounded by the piezoelectric transducer; an instrument rod connected to the other end of the first amplitude-change pole, an instrument working portion being located outside the shell and connected to the instrument rod, and the instrument rod being rotatable relative to the first amplitude-change pole; and a rotation transmission assembly rotatably mounted on the shell and matched with the instrument rod to transmit rotation torque to the instrument rod.

A medical or dental handpiece has a grip. The grip includes first to third rotation shafts. The first and second shafts are connected through a first gear mechanism and the second and third shafts are connected through a second gear mechanism so that a rotation is transmitted from the first shaft through the first gear mechanism to the second shaft and then from the second shaft through the second gear mechanism to the third shaft. The first or second gear mechanism has an internal gear secured on one shaft and an external gear secured on the other shaft, the internal and the external gears being engaged with each other. The external gear is substantially enclosed within a cylindrical plane extending along a peripheral edge of the internal gear.

A wall portion of a dental handpiece accommodates a cam pin 111 with a cam hole 21 or a cam groove 211 designed so that the size of the cam hole 21 or the cam groove 211 is larger than the size of the cam pin 111 in each of the axial direction and the circumferential direction of a vibration cylinder 20. Therefore, a rotating member 110 is rotationally driven, and a vibrating force acts on the vibration cylinder 20 in the axial direction through the cam pin 111. In this manner, the vibration cylinder 20 vibrates or reciprocates in the axial direction with respect to a second cylindrical member 12, and vibrates or reciprocates in the circumferential direction. In addition, a needle portion 42 protruding from a through-hole 202 of the vibration cylinder 20 vibrates while being bent.