A dental handpiece including an outer casing, a handpiece head, a tool receiver disposed in the handpiece head, the tool receiver is electrically conductive, a drive chain that includes a drive unit and a drive shaft drivable by the drive unit, the drive shaft being coupled to the tool receiver, a slip ring disposed around a section of the tool receiver and in mechanical and electrical connection with the tool receiver, and a prestressed bifurcated contact in mechanical and electrical connection with the slip ring. The prestressed bifurcated contact impinges on the slip ring which impinges on the tool receiver to deliver electrical signals from a connection interface a tool inserted in the tool receiver during use of the dental handpiece. The signal path includes the prestressed bifurcated contact. The drive chain, and the signal path are electrically isolated from the outer casing via ball bearings.

Apparatuses and methods are provided for displaying the position of a dental file during endodontic treatment. Data showing the morphology of a tooth is obtained. In one embodiment, the data is X-ray image data. A three-dimensional representation of the dental file positioned in the tooth is generated, and a length that the dental file extends from an upper surface of the tooth is determined from the three-dimensional representation. A representation of the dental file is provided in the image of the tooth obtained from the data showing the tooth morphology, with the representation of the dental file being depicted such that a part of the representation of the dental file extends from the upper surface of the tooth in proportion to the length that the dental file extends from the upper surface of the tooth as determined from the three-dimensional representation and such that a remaining part of the representation of the dental file extends into the tooth, with a part of the remaining part of the representation of the dental file being positioned in the root of the tooth in the image. The image of tooth and representation of the dental file may be displayed.