Abstract: A dental handpiece stably cutting a wall of a root canal without a fear of piercing a root opening. The dental handpiece includes a means for holding a tool cutting a tooth to be cured and a support for setting the cutting tool at a desired position relative to the tooth to be cured. The length of the support may be changeable by stages. The holding means may be formed of a head of the dental handpiece and a plurality of supports with different lengths may be removably mounted to the head. The support can stand on a head of the dental handpiece and the length from the head is changeable. The support is formed separately from the dental handpiece to be removable, and may have a stopper which abut with a tooth to be cured or an appropriate portion near the tooth.

Abstract: A dental handpiece to securely detect the load applied to the handpiece itself, and when an excessive load is applied to the handpiece, the cutting operation is suspended. The dental handpiece includes: a head; a support mounted in the head to support a cutting tool; and a transmission mounted in the head to transmit driving force to the support. The support and the transmission are slidably connected with each other. In the dental handpiece, the support may be cylindrical and can be provided with a plurality of inclined projections that are arranged in a longitudinal direction of an outer periphery of the cylinder; the transmission may be provided with engaging projections with inclined faces parallel to inclined faces of the plurality of inclined projections; and the transmission can be provided with resiliency that allows the engaging projections movable in a direction departing from the inclined projections.

Abstract: A dental handpiece to securely detect the load applied to the handpiece itself, and when excessive load is applied to the handpiece cutting operation is suspended. The dental handpiece according to the present invention comprises: a head; a support mounted in the head to support a cutting tool; and a transmission mounted in the head to transmit driving force to the support; wherein the support and the transmission are slidably connected with each other. In the above dental handpiece, the support may be cylindrical and can be provided with a plurality of inclined projections that are arranged in a longitudinal direction of an outer periphery of the cylinder; the transmission may be provided with engaging projections with inclined faces parallel to inclined faces of the plurality of inclined projections; and the transmission can be provided with a resiliency that allows the engaging projections resiliently movable in a direction apart from the inclined projections.

Abstract: A dental handpiece stably cutting a wall of a root canal without a fear of piercing a root opening. The dental handpiece includes a means for holding a tool cutting a tooth to be cured and a support for setting the cutting tool at a desired position relative to the tooth to be cured. The length of the support may be changeable by stages. The holding means may be formed of a head of the dental handpiece and a plurality of supports with different lengths may be removably mounted to the head. The support can stand on a head of the dental handpiece and the length from the head is changeable. The support is formed separately from the dental handpiece to be removable, and may have a stopper which abut with a tooth to be cured or an appropriate portion near the tooth.