Handpiece having a root canal length measurement function

Abstract

The present invention discloses a handpiece having a root canal length measurement function, wherein a signal circuit, which is specifically provided for sending measurement signals from a root canal length measurement circuit to a measurement probe mounted on a head provided at the tip of the handpiece, is incorporated in the handpiece, and the signal circuit is electrically connected to the measurement probe via a contact piece in the vicinity of the measurement probe. Therefore, it is not necessary to connect the signal circuit for measurement by way of the outside of the handpiece. In addition, this structure improves the operability of the handpiece because there is no lead wire for connection. Furthermore, this structure eliminates the troublesome task of externally connecting lead wires to the head of the handpiece, which would otherwise be required at each treatment time. Moreover, the signal circuit is securely formed without passing through a drive power transmission mechanism, thereby preventing unstable operation of root canal length measurement due to instantaneous opening of the signal circuit. Additionally, it is possible to use a cutting tool having a shank portion and a cutting portion insulated from each other.