The invention provides a unitary cordless dental drive apparatus with a cantilever arm extending outward and positioned to allow a dental nose cone to be connected. An activating switch is located at the free end of the cantilever arm in a position that is convenient for manipulation by a user. In a second embodiment, the switch is in the form of a contactor mounted below the cantilever arm to contact the nose cone when pressed. In a third embodiment, a foot pedal connected to a wireless transmitter is provided to send a signal to a receiver located within the handpiece for activating the handpiece.

The invention relates to a dental instrument, comprising a gearing for driving a tool, wherein at least one torque limiting device is provided, which can be brought into contact with the gearing, as a result of which the maximum acting torque in the gearing can be limited.

A tooth bracket extraction device which comprises a motor housed within a motor housing, and a motor shaft extending from the motor. A gear cover is fastened to the motor housing, and a first shaft is coupled to the motor shaft, where the first shaft receives the drive from the motor via the motor shaft. A first gear is attached to the first shaft, and a second shaft comprises a second gear, where the second shaft is in communication with the first shaft via engagement of the second gear to the first gear. A torque generated from the motor is transferred to the second shaft, and the second shaft comprises a head receiver member which is configured to receive and mount a plurality of heads. Each head is configured to transfer the torque to a bracket section attached to teeth, thereby removing the bracket section from the teeth.

A motor-driven dental device has a motor control that is responsive to a load placed upon the motor. More specifically, the invention relates to a dental device having motor that drives a tool, wherein the tool is activated or otherwise controlled in response to a load placed upon the motor through the tool, such as by touching the tool to a surface. The tool may also be controlled by the sustenance, over a predetermined time period, of an increase or decrease in motor current beyond a predetermined hysteresis current threshold. The motor may be an electric motor, a rotary electric motor, and air driven motor, an ultrasonic device or the like.

A medical or dental device for determining a bone's quality by cutting a thread into the bone with a rotating threaded element comprises a control unit having a measurement circuit configured: (i) to determine values of the motor current via a first electrical contact device with which the motor drive is supplied for rotational drive of the threaded element that can be connected to the motor drive, the current values being a measure of the bone's quality; (ii) to monitor and/or to determine the penetration depth of the threaded element into the bone, and (iii) to generate measurement signals which show the relationship between the penetration depth and the determined current values or parameters derived therefrom, and to transmit these signals to a display unit, which displays the relationship between the determined current values or parameters derived therefrom, in particular the bone's quality, and the penetration depth.

A method for cutting with a tool comprises rotating the tool in a first direction. Then, at a predetermined moment, quit rotating the tool and allow the tool to coast in the first direction. While the tool coasts, a parameter is determined that represents drag experienced by the tool as the tool coasts. If the determined parameter does not exceed a predetermined limit then the tool is rotated in the first direction. If the determined parameter exceeds the predetermined limit, then the tool is rotated in another direction opposite the first direction. The predetermined moment when the tool begins to coast may be any desired moment, such as when the tool rotates through a specific distance or for a specific period of time.

An endodontic file system is provided for simultaneously cleaning and shaping multiple root canals, the system includes a drill head having a distal portion and a proximal portion; at least two adjustable couplers on the distal portion of the drill head, each adjustable coupler configured to secure an endodontic file for cleaning a root canal; and a rotary system configured to rotate each adjustable coupler, where at least one endodontic file has an adjustable working distance from the drill head to a root canal of a tooth. In an example, each adjustable coupler can be configured to have a torque control configured to allow for controlling the rotation of the adjustable coupler based on an amount of torque.

A tooth bracket extraction device which comprises a motor housed within a motor housing, and a motor shaft extending from the motor. A gear cover is fastened to the motor housing, and a first shaft is coupled to the motor shaft, where the first shaft receives the drive from the motor via the motor shaft. A first gear is attached to the first shaft, and a second shaft comprises a second gear, where the second shaft is in communication with the first shaft via engagement of the second gear to the first gear. A torque generated from the motor is transferred to the second shaft, and the second shaft comprises a head receiver member which is configured to receive and mount a plurality of heads. Each head is configured to transfer the torque to a bracket section attached to teeth, thereby removing the bracket section from the teeth.

The present invention relates to a torsional vibration resonance frequency measuring method and a novel amplitude transformer for assessing the stability of dental implants. In one example, a torsional vibration resonance frequency measuring method includes installing an amplitude transformer on a dental implant, energizing a torsional vibration mode, gathering resonance signals, and analyzing a resonance frequency. In another example, an amplitude transformer for measuring torsional vibration resonance frequency in a dental implant, includes an anti-rotary horizontal double-winged component and a central bolt. The central bolt is configured to closely connect with the inner threads of the dental implant, such that the amplitude transformer can integrate with the dental implant sufficient to vibrate as an integral structure under energizing.

A torque-limiting assembly for a surgical powertool has an input shaft and an output shaft. Two relatively rotatable parts of the assembly are configured to be locked against relative rotation by at least one shearable piece for torque transfer between the input shaft and the output shaft up to a torque limit. The assembly further comprises at least one shear off structure rotationally fixed to one of the two relatively rotatable parts for shearing off a portion of the at least one shearable piece above the torque limit so as to unlock the two relatively rotatable parts for relative rotation.