A dental handpiece for root canal treatment comprises an outer sleeve, a connecting device for connecting the handpiece to a control and analyzing unit, a measurement circuit having a power source and to a drive unit, an electrically conducting tool receptacle and an electrically conducting driving device, wherein the tool receptacle and the driving device are mechanically and electrically connected together so that a driving motion generated by the drive unit can be transmitted via the driving device to the tool receptacle and electrical measurement signals can be transmitted between the driving device and the tool receptacle. A first connection is provided for transmitting the driving motion. A second electrically conducting connection, which may comprise sliding contacts, is provided for transmitting the electrical measurement signals. With separate connections, an improved signal transmission and in particular a low loss of measurement signals of the root canal length measurement during the signal transmission are achieved.