In the case of a dental hand instrument having a grip sleeve and also a head housing arranged at the front end of the grip sleeve for receiving or holding a treatment instrument, the head housing has a substantially cylindrical hollow space which is connected by way of at least one connecting bore to a connection region pointing to the grip sleeve, wherein the connecting bore is coupled, at its end facing the grip sleeve, to a media line extending through the grip sleeve, and wherein the inner wall region of the head housing enclosing the hollow space has a recess into which the connecting bore opens.

In the case of a dental hand instrument having a grip sleeve and also a head housing arranged at the front end of the grip sleeve for receiving or holding a treatment instrument, the head housing has a substantially cylindrical hollow space which is connected by way of at least one connecting bore to a connection region pointing to the grip sleeve, wherein the connecting bore is coupled, at its end facing the grip sleeve, to a media line extending through the grip sleeve, and wherein the inner wall region of the head housing enclosing the hollow space has a recess into which the connecting bore opens.

A dental hand piece has: a hand piece head provided at the front end section thereof; and a connection section provided at the rear end section thereof, and the dental hand piece is used by connecting the connection section to a dental unit. The dental hand piece is provided with: a plurality of metallic pipes for providing communication between the hand piece head and the connection section; and an elastic resin member mounted so as to cover a portion extending at least from the rear end section of the hand piece head to the front end section of the connection section. The outer peripheries of the metallic pipes are embedded within the elastic resin member so as to be in close contact with the inside thereof.

A dental hand piece has: a hand piece head provided at the front end section thereof; and a connection section provided at the rear end section thereof, and the dental hand piece is used by connecting the connection section to a dental unit. The dental hand piece is provided with: a plurality of metallic pipes for providing communication between the hand piece head and the connection section; and an elastic resin member mounted so as to cover a portion extending at least from the rear end section of the hand piece head to the front end section of the connection section. The outer peripheries of the metallic pipes are embedded within the elastic resin member so as to be in close contact with the inside thereof.

An apparatus for endodontic treatment, comprising: a nozzle connected to a fluid source comprising: a tip small enough to be inserted into a pulp chamber of a tooth; an inner geometry which forms a flow parameters including non-axial flow direction of nozzle fluid flowing through the inner geometry such that discharge fluid discharged from the inner geometry increase rotation of root canal fluid within a root canal sufficiently to remove tissue from the root canal.

The angle piece head drives an instrument for operating on dental roots and includes a body having a generally cylindrical cavity and an instrument-holding core in the cavity. The core is shaped to receive and hold the instrument and moves axially and pivotally. The instrument-holding core includes a groove having an offset engaging therewith. The offset engages with one or the other of the two edges of the groove such that the rotation thereof transmits an alternating axial movement to the instrument while enabling same to rotate about the axis of the instrument. The groove includes two portions that extend on either side of a median area. For each portion, the height, namely the distance that separates the two edges, increases from the median area to each end of the groove.

The angle piece head drives an instrument for operating on dental roots and includes a body having a generally cylindrical cavity and an instrument-holding core in the cavity. The core is shaped to receive and hold the instrument and moves axially and pivotally. The instrument-holding core includes a groove having an offset engaging therewith. The offset engages with one or the other of the two edges of the groove such that the rotation thereof transmits an alternating axial movement to the instrument while enabling same to rotate about the axis of the instrument. The groove includes two portions that extend on either side of a median area. For each portion, the height, namely the distance that separates the two edges, increases from the median area to each end of the groove.

A multi-directional handpiece that includes a motor drive extending along and configured for rotation about a body axis, the motor drive having: a motor gearing at a proximal end of the motor drive; and a file gearing in engagement with the motor gearing for transferring the rotational and axial movement to a workpiece; and a housing for the workpiece; and wherein through rotation of the motor drive, the workpiece moves in an axial oscillating motion while being rotated.

A multi-directional handpiece that includes a motor drive extending along and configured for rotation about a body axis, the motor drive having: a motor gearing at a proximal end of the motor drive; and a file gearing in engagement with the motor gearing for transferring the rotational and axial movement to a workpiece; and a housing for the workpiece; and wherein through rotation of the motor drive, the workpiece moves in an axial oscillating motion while being rotated.

To provide an air injection device for a dental handpiece which makes it possible to obtain a clear image even if the position of an image taking part is changed, provided is an air injection device including: a trunk connector (41) that is in a form of a column, in the trunk connector a passage being formed; an air guiding pipe (45) that is in a form of a pipe, one end of the air guiding pipe being connected to the trunk connector, the air guiding pipe having flexibility; and a means (46) that retains the air guiding pipe in the dental handpiece main body, wherein the passage in the trunk connector branches, one of the branching passages communicating with the air guiding pipedental handpiece.