A dental treating apparatus according to the present invention includes: a hand piece; a head unit; a driving unit; a resistor for load detection; a load comparing unit; and a control unit. The hand piece drivably holds a cutting tool on the head unit. The driving unit drives the cutting tool in a normal rotation direction or in a reverse rotation direction. The resistor for load detection detects a load applied to the cutting tool. The load comparing unit compares the detected load and a reference load each time driving for rotating the cutting tool in the reverse rotation direction by a predetermined rotation angle is performed. The control unit controls the driving unit based on a result of comparison by the load comparing unit.

Methods for controlling and/or regulating of a compressed-gas-operable medical or dental drive device and a control and/or regulating device for performing such methods are described. In one method according to a first embodiment, a rotor of the drive device is operated at an essentially constant rotational speed (n.sub.1) by adjusting the gas pressure and/or the flow rate of the compressed gas through a valve and the rotational speed is reduced on reaching a pressure value (p.sub.2) of the compressed gas which is lower than the maximum gas pressure (p.sub.max) of the compressed gas. In the case of a method according to a second embodiment, the gas pressure of the compressed gas and the rotational speed of the rotor are altered on reaching a rotational speed limit value (n.sub.2, n.sub.3) of the rotor by adjusting the valve.

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.

Embodiments of a medical or dental handpiece are disclosed. A medical or dental handpiece may include a rotatable drive element to drive a tool that can be connected to the handpiece, a rotational speed measuring device which is designed to generate a variable electric rotational speed measurement signal assigned to the rotational speed of the drive element, a lighting device that can be supplied with electric power for emitting radiation, in particular visible light, onto a treatment site, and at least one shared electric line, which is provided for transmitting electric power to the illumination device and the rotational speed measurement signal of the rotational speed measurement device. Further a corresponding method for the operation of a medical or dental handpiece is disclosed.

Embodiments of a medical or dental handpiece are disclosed. A medical or dental handpiece may include a rotatable drive element to drive a tool that can be connected to the handpiece, a rotational speed measuring device which is designed to generate a variable electric rotational speed measurement signal assigned to the rotational speed of the drive element, a lighting device that can be supplied with electric power for emitting radiation, in particular visible light, onto a treatment site, and at least one shared electric line, which is provided for transmitting electric power to the illumination device and the rotational speed measurement signal of the rotational speed measurement device. Further a corresponding method for the operation of a medical or dental handpiece is disclosed.

A hand held instrument and method in which a working element is to be placed by an operator into contact with a workpiece employ a laser proximity sensor arrangement adapted to sense proximity of the working element to the workpiece. A controller is responsive to the proximity sensor arrangement for activating a power source to actuate the working element in response to the working element reaching a predetermined proximity to the workpiece, as the working element is moved by the operator toward placement into contact with the workpiece. The predetermined proximity is such that the working element will reach a fully-operating condition prior to contact with the workpiece, whereby the working element will be at the fully-operating condition upon contact with the workpiece.

An apparatus for controlling asymmetrical coasting of an endodontic reciprocating motor includes a controller operatively connected to the endodontic motor. The controller may include a processing unit that is configured to direct the rotation of the endodontic motor in the forward direction for a coast time and configured to direct the rotation of the endodontic motor in the reverse direction for a coast time. The forward coast time is separately calculated from the reverse coast time. A method for asymmetrically coasting a reciprocating endodontic motor includes rotating an endodontic motor in a forward direction and calculating a forward coast time for the forward direction and coasting the endodontic motor in the forward direction for the calculated forward coast time. After coasting the endodontic motor in the forward direction, the endodontic motor is rotated in a reverse direction. The reverse coast time is different than the forward coast time.

A quick stop drilling tool for use with a medical or dental treatment device includes a drilling tool having a body extending between a connection end and a working end and having a longitudinal extension along a longitudinal axis of the drilling tool. The drilling tool has a hollow outer shell in which a probe is held that can be moved along the longitudinal axis so that a part of the probe can be moved out of the shell through an opening. The probe is designed as an elongated pin, and its first end facing the connection end is held in the interior of the hollow outer shell. An electromagnetic sensor for detecting relative movement between the shell and the probe is arranged along the longitudinal extension of the body. The drilling tool has a channel for a treatment fluid extending along the longitudinal axis.

An automated dental drill includes an end effector, including a dental tool for disposition at least partially in a patient's mouth and to perform an operation on a tooth. A tooth clamp releasably rigidly attaches to at least one tooth. A drive assembly is controlled by a processor and positions the end effector with a first at least three degrees of freedom, relative to the tooth clamp. The drive assembly remains outside the patient's mouth. A clamp connector connects the tooth clamp to the drive assembly. With the tooth clamp coupled to the drive assembly and the tooth clamp attached to the at least one tooth, position and orientation of the drive assembly remain fixed, relative to the at least one tooth. A passive cantilever arm, mechanically coupled between a support structure and the drive assembly, has a second at least three degrees of freedom and supports the drive assembly.

A dental treatment apparatus according to the present invention includes a drive unit that includes a micromotor, a motor driver, and the like, a controller, and a root canal length measurement circuit. The controller controls the cutting tool to be held at a head forward driven in a direction of cutting of an object to be cut. The controller also controls the cutting tool to be reverse driven in a direction reverse to forward rotation drive when the cutting tool is forward driven and the root canal length measurement circuit detects a tip end of the cutting tool reaching a reference position. The controller further carries out a fail-safe control when the cutting tool is reverse driven and the root canal length measurement circuit detects movement of the tip end of the cutting tool toward a root apex position.