Endodontic instruments are used to clean and enlarge the endodontic cavity space (ECS), also known as the root canal system, of a human tooth. This document describes novel endodontic instruments that are radially compressible, and methods for their use.

An electrical discharge irrigation includes a power source to produce a first voltage, a circuit coupled to the power source to convert the first voltage to a second voltage, a discharge capacitor to receive the second voltage from the circuit, a transistor and/or a controlled rectifier coupled to the discharge capacitor to receive the second voltage, and an output tip. This tip is coupled to a transistor and/or a controlled rectifier and includes a first end, a second end, a longitudinal axis extending between them, an electrode located in an interior space of the tip to receive an electrical charge from the a transistor and/or a controlled rectifier and to release an electric discharge, and a ground return. The ground return is an outside surface of the tip. A space between the electrode and the ground return holds a conductive medium in contact with the electrode and the ground return.

The present disclosure relates to a dynamic self-adaptive reciprocal motor movement optimized for root canal treatment with endodontic files. A smart motor movement is configured to continuously self-adapt its settings in a smooth manner without sudden drastic motor movement changes. This can be obtained by continuously changing motor parameters in response to instantaneous torque measurements, and also taking into consideration the torque evolution instead of merely reacting to the instantaneous torque imposed on the file.

An electrical discharge irrigation device includes a power source to produce power of a first voltage, a circuit coupled to the power source to convert the power of the first voltage to power of a second voltage where the second voltage is higher than the first voltage, a trigger to activate the circuit, an igniter coupled to the circuit to produce a spike, an electrical charge storage component coupled to the igniter the electrical charge storage component becoming conductive and storing an electrical charge after receiving the spike, and an output tip. The output tip includes an electrode and insulating material as an outer layer.

An electrical discharge irrigation device includes a power source to produce power of a first voltage, a circuit coupled to the power source to convert the power of the first voltage to power of a second voltage where the second voltage is higher than the first voltage, a trigger to activate the circuit, an igniter coupled to the circuit to produce a spike, an electrical charge storage component coupled to the igniter the electrical charge storage component becoming conductive and storing an electrical charge after receiving the spike, and an output tip. The output tip includes an electrode and insulating material as an outer layer.

A reciprocating endodontic hand tool in which the torque applied to an instrument such as a debriding file can be set at or below an endurance limit of the file below which failure of the instrument will not occur. In preferred embodiments the tool can switch between settings in which the torque applied to the instrument is between the endurance limit of the file and an elastic limit of the file, by setting forward and reverse angles of rotation within specified limits. This reduces or eliminates opportunities for plastic distortion, fatigue and breakage of the file during the canal debriding/cleaning/shaping process in a root canal treatment or retreatment. In some embodiments the torque may be set to at or below a durability limit of the file below which failure of the instrument will not occur through repetitive strain over the course of a particular root canal treatment or retreatment.

A reciprocating endodontic hand tool in which the torque applied to an instrument such as a debriding file can be set at or below an endurance limit of the file below which failure of the instrument will not occur. In preferred embodiments the tool can switch between settings in which the torque applied to the instrument is between the endurance limit of the file and an elastic limit of the file, by setting forward and reverse angles of rotation within specified limits. This reduces or eliminates opportunities for plastic distortion, fatigue and breakage of the file during the canal debriding/cleaning/shaping process in a root canal treatment or retreatment. In some embodiments the torque may be set to at or below a durability limit of the file below which failure of the instrument will not occur through repetitive strain over the course of a particular root canal treatment or retreatment.

A method is provided that includes injecting, during a dental procedure, from a first side of a bone, through (a) exactly one bore that passes through the bone from the first side to a second side of the bone, and (b) into a cavity adjacent to the second side of the bone, a solid-liquid composition of solid particles and a physiological liquid solution. During the dental procedure, the physiological liquid solution is drained from the cavity and through the bore while inhibiting passage of the solid particles of the solid-liquid composition, such that the solid particles accumulate in the cavity. Injecting the solid-liquid composition includes pumping the solid-liquid composition at a pulsating positive hydraulic pressure.

A medical or dental handpiece has a grip. The grip includes first to third rotation shafts. The first and second shafts are connected through a first gear mechanism and the second and third shafts are connected through a second gear mechanism so that a rotation is transmitted from the first shaft through the first gear mechanism to the second shaft and then from the second shaft through the second gear mechanism to the third shaft. The first or second gear mechanism has an internal gear secured on one shaft and an external gear secured on the other shaft, the internal and the external gears being engaged with each other. The external gear is substantially enclosed within a cylindrical plane extending along a peripheral edge of the internal gear.

A medical or dental handpiece has a grip. The grip includes first to third rotation shafts. The first and second shafts are connected through a first gear mechanism and the second and third shafts are connected through a second gear mechanism so that a rotation is transmitted from the first shaft through the first gear mechanism to the second shaft and then from the second shaft through the second gear mechanism to the third shaft. The first or second gear mechanism has an internal gear secured on one shaft and an external gear secured on the other shaft, the internal and the external gears being engaged with each other. The external gear is substantially enclosed within a cylindrical plane extending along a peripheral edge of the internal gear.