A dental handpiece control apparatus including: a relay 17 that switches a polarity of a voltage applied to a motor 20, and thereby switches a rotation direction of the motor 20 to forward rotation and backward rotation, the motor 20 being incorporated in the dental handpiece to rotate a cutting tool (a file) mounted to the dental handpiece; and a control section 11 that controls the switching of the voltage polarity by the relay 17 based on a rotation angle θ.sub.F for forward rotation and a rotation angle θ.sub.R for backward rotation of the motor 20, the rotation angle θ.sub.F and the rotation angle θ.sub.R being associated with state information of the file.

A tip assembly for use with a dental tool, the tip assembly comprising a housing for attaching to the dental tool, at least one aspiration needle having a passageway extending at least partially through the aspiration needle, a substantial length of the aspiration needle, or at least from one end to the other end of the aspiration needle, the passageway providing a single continuous path to aspirate the irrigant and/or debris from the root canal cavity of the tooth, and at least one irrigation needle having a passageway extending at least partially through the irrigation needle, a substantial length of the irrigation needle, or at least from one end to the other end of the irrigation needle, the passageway provides a continuous flow path for delivering fluid/irrigant from a reservoir in communication with a proximal end of the irrigation needle to the distal end of the irrigation needle and into a root canal/coronal opening of a tooth.

A tip assembly for use with a dental tool, the tip assembly comprising a housing for attaching to the dental tool, at least one aspiration needle having a passageway extending at least partially through the aspiration needle, a substantial length of the aspiration needle, or at least from one end to the other end of the aspiration needle, the passageway providing a single continuous path to aspirate the irrigant and/or debris from the root canal cavity of the tooth, and at least one irrigation needle having a passageway extending at least partially through the irrigation needle, a substantial length of the irrigation needle, or at least from one end to the other end of the irrigation needle, the passageway provides a continuous flow path for delivering fluid/irrigant from a reservoir in communication with a proximal end of the irrigation needle to the distal end of the irrigation needle and into a root canal/coronal opening of a tooth.

An instrument (10) having a working section (11) that terminates in an end zone (12) having a pointed tip. The end zone (12) has, on the one hand, a conical guiding section (13) which ends in a tip. This guiding section (13) has a tip angle of between 10° and 60° and, on the other hand, an angular cutting section (14) adjacent to the conical guiding section (13) which has three cutting edges (15). The angular cutting section (14) extends over a certain length and is located intermediate between the conical guiding section (13) and the working section (11). The angular cutting section (14) has a cross-section that progressively increases from the base of the conical guiding section (13) over at least a portion of its length.

An instrument (10) having a working section (11) that terminates in an end zone (12) having a pointed tip. The end zone (12) has, on the one hand, a conical guiding section (13) which ends in a tip. This guiding section (13) has a tip angle of between 10° and 60° and, on the other hand, an angular cutting section (14) adjacent to the conical guiding section (13) which has three cutting edges (15). The angular cutting section (14) extends over a certain length and is located intermediate between the conical guiding section (13) and the working section (11). The angular cutting section (14) has a cross-section that progressively increases from the base of the conical guiding section (13) over at least a portion of its length.

Disclosed is a digital measurement apparatus including a holding unit on which a measurement object to be measured is placed; and a measurement unit for measuring the measurement object by comparing an image of the measurement object placed on the holding unit with a preset reference value, and providing a reference for adjusting the length of a new measurement object based on a measured value of the measurement object. With this configuration, regardless of photographing conditions, by performing calibration using a set reference value, the accuracy of a measured value may be improved.

An instrument for drilling dental root canals includes a tapered rod having over at least a part of its length—the active part—a polygonal cross-section forming at least two cutting edges, the active part terminating by a point and being defined by an envelope of cylindrical or conical shape, whose longitudinal axis coincides with the instrument's axis of rotation. The active part has a first portion extending from the point and a second portion extending following the first portion towards the rear of the active part. At least one cross-section of the first portion has a center of mass located on the axis of rotation and the cutting edges are located on the envelope. Any cross-section of the second portion has a center of mass offset with respect to the axis of rotation and at least one cutting edge defined by the cross-section is located set back.

An instrument for drilling dental root canals includes a tapered rod having over at least a part of its length—the active part—a polygonal cross-section forming at least two cutting edges, the active part terminating by a point and being defined by an envelope of cylindrical or conical shape, whose longitudinal axis coincides with the instrument's axis of rotation. The active part has a first portion extending from the point and a second portion extending following the first portion towards the rear of the active part. At least one cross-section of the first portion has a center of mass located on the axis of rotation and the cutting edges are located on the envelope. Any cross-section of the second portion has a center of mass offset with respect to the axis of rotation and at least one cutting edge defined by the cross-section is located set back.

Medical instruments, particularly, endodontic instruments with unique limited memory characteristics, and methods for making such instruments. One embodiment includes heat treating a finished endodontic instrument. A related embodiment includes electropolishing a finished endodontic instrument and then heat treating the endodontic instrument.

Medical instruments, particularly, endodontic instruments with unique limited memory characteristics, and methods for making such instruments. One embodiment includes heat treating a finished endodontic instrument. A related embodiment includes electropolishing a finished endodontic instrument and then heat treating the endodontic instrument.