Abstract: An endodontic file for a motorized rotary handpiece includes a coupler element for coupling to the handpiece, a central longitudinal flexible core including a central flexible cable supported by the coupler element, and a helical wire surrounding the core and extending toward a tip of the core opposite the handle end. The flexible core includes a first plurality of inner strands twisted together in a first direction and surrounded by a second plurality of outer strands twisted in an opposite direction. The tip of the core is chamfered and unbonded and protrudes beyond the helical wire at the tip whereby in use reversing a direction of rotation of the endodontic file after the tip of the core reaches the apex of the root canal, unwinds the outer strands, which operate as a brush during removal of the endodontic file from the root canal.

Abstract: An endodontic file for a motorized rotary handpiece includes a coupler element for coupling to the handpiece, a central longitudinal flexible core including a central flexible cable supported by the coupler element, and a helical wire surrounding the core and extending toward a tip of the core opposite the handle end. The flexible core includes a first plurality of inner strands twisted together in a first direction and surrounded by a second plurality of outer strands twisted in an opposite direction. The tip of the core is chamfered and unbonded and protrudes beyond the helical wire at the tip whereby in use reversing a direction of rotation of the endodontic file after the tip of the core reaches the apex of the root canal, unwinds the outer strands, which operate as a brush during removal of the endodontic file from the root canal.

Abstract: A root canal length measurement device configured for detachable support on a neck of a dental handpiece and having a generally cylindrical electrical contact element that, in use, is resiliently biased by a spring toward an endodontic file rotatably mounted in the handpiece so that a flat surface of the contact element maintains a steady electrical connection with a shank portion of the endodontic file proximate its point of attachment to the handpiece.