The disclosure relates to a head bearing assembly for a dental or surgical handpiece, comprising an outer sleeve, in which at least four radial bearings are arranged, which enclose an axis of rotation and each have their own bearing outer ring or a common bearing outer rings, wherein the bearing outer rings are surrounded radially on the outside by the outer sleeve in the circumferential direction about the axis of rotation, and each radial bearing has at least one or exactly one rolling element row with rolling elements which are arranged one behind the other in the circumferential direction and rolling in the respective bearing outer ring. The head bearing assembly according to the disclosure is characterized in that the at least four radial bearings have a common, integral bearing inner ring on which the rolling elements are arranged in rolling contact.

A support structure, which supports a drive shaft performing reciprocating motion. The support structure comprises an inner fixing ring of the support structure, at least one elastic member of the support structure, and an outer fixing ring of the support structure; the inner fixing ring is fastened on the drive shaft; the outer fixing ring is fastened on an inner wall of a lower device housing; the elastic member is provided between the outer fixing ring and the inner fixing ring; and on the cross section of the elastic member perpendicular to the radial direction of the drive shaft, the width (b.sub.1) in the direction perpendicular to a drive force is three times larger than the thickness (t.sub.1) in the direction parallel to the drive force. The support structure has the advantages of low noise, low energy loss, low cost, simple structure, and being suitable for batch production.

In some embodiments, the current invention relates to a method and/or system for using a standard dental handpiece for endodontic cleaning. For example, a dental adapter is disclosed having a fitting for a standard dental handpiece, a torque limiter and/or a mount for an endodontic file. For example, the adapter may be single use and/or multi use. In some embodiments, the mount includes the torque limiter. For example, an endodontic file may be connected to the mount with a friction fitting that allows rotation of the file with respect to the mount at high torque. Optionally the mount is positioned eccentrically with respect to the fitting.

Dental hand piece, comprising a housing and a drive train with a coupling element for a drive, wherein the housing radially surrounds the drive train and wherein the housing has a first and a second housing end, and wherein the housing is held on the drive train on the first and on the second housing end. Between the first housing end and the coupling element is arranged a decoupling element, which is strictly springy or springy and damping in the axial direction, whereas the second housing end is braced rigidly against the drive train and the housing is braced with respect to the coupling element in the axial direction by means of the decoupling element.

A dental hand piece or angle piece including a rotating tool, which is driven via a rotating drive element disposed in a housing, wherein the rotating drive element is mounted in the housing by a radial rolling bearing, wherein the rolling bearing comprises an axial abutment surface and the housing comprises an axial countersurface, and wherein the rolling bearing is axially preloaded with respect to the housing by a spring element 11 and has a coefficient of friction for the static friction of the abutment surface to the countersurface or the abutment surface and the countersurface to the spring element that is at least 0.16 in the lubricated state and at least 0.25 in the unlubricated state.

An electrical toothbrush transmission connection structure includes a transmission shaft and a motor. The transmission shaft has a first sleeve at one end. The first sleeve has a first connection section. The motor has a rotary shaft. A second sleeve is disposed on the rotary shaft. The second sleeve has a second connection section. The first and second connection sections have corresponding cross-sectional shape and are correspondingly connected with each other so that the electrical toothbrush transmission connection structure has better transmission connection structure and effect.

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 toothbrush includes a removable, replaceable brush head that includes a clip that also serves as a removal tool for a spent brush head. The toothbrush may be a manually-wound or charged, powered toothbrush that includes a winding mechanism, an energy storage element, and an output gear train to cause a rotating, oscillating or sweeping brush head to move, thus improving the efficacy of the user's oral-care regimen.

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.

When the compressed air is not applied, an inclined surface, which is positioned at an upstream side with respect to the supply direction of the compressed air, of the lip part is in contact with the inclined surface of the inner ring. When the compressed air is applied, a contact area between the inclined surface, which is positioned at the upstream side with respect to the supply direction of the compressed air, of the lip part and the inclined surface of the inner ring becomes smaller, as compared to when the compressed air is not applied.