Apparatus and methods for removing a dental crown from a tooth. Chemical bonds within an adhesive, between the adhesive and the crown, and between the adhesive and the tooth may secure the crown to the tooth. The chemical bonds may be weakened. After weakening the bonds, the crown may not be securely affixed to the tooth. After weakening the bonds, the crown may be easily removed from the tooth. The bonds may be weakened by applying ultrasonic waves to the adhesive. Sonic energy of the waves may heat the adhesive. The bonds may be weakened by positioning the adhesive within an electric field. The bonds may be weakened by applying heat to the adhesive. The heating may cause particles within the adhesive to expand. The electric field and/or the sonic energy may be applied via an electronic tool.

Apparatus and methods for removing a dental crown from a tooth. Chemical bonds within an adhesive, between the adhesive and the crown, and between the adhesive and the tooth may secure the crown to the tooth. The chemical bonds may be weakened. After weakening the bonds, the crown may not be securely affixed to the tooth. After weakening the bonds, the crown may be easily removed from the tooth. The bonds may be weakened by applying ultrasonic waves to the adhesive. Sonic energy of the waves may heat the adhesive. The bonds may be weakened by positioning the adhesive within an electric field. The bonds may be weakened by applying heat to the adhesive. The heating may cause particles within the adhesive to expand. The electric field and/or the sonic energy may be applied via an electronic tool.

The handpiece includes; an outer housing of a bar shape; a cylindrical core inserted into the outer housing and having an air hole and a water hole; pipes respective inserted into the air hole and the water hole of the core; a rotor made with a cylindrical magnetic material and inserted into the core; cylindrical support rings forcedly fit to both sides of transfer shafts of the rotor; a pair of bearings respectively disposed at the front side and the rear side of the support rings; a coupling disposed in front of the rotor; a front housing joined to the front of the outer housing; a front cap disposed at the rear of the core; a rear cap disposed at the rear of the front cap and having a power supply terminal disposed at one side thereof; and a rear housing joined to the rear of the outer housing.

The handpiece includes; an outer housing of a bar shape; a cylindrical core inserted into the outer housing and having an air hole and a water hole; pipes respective inserted into the air hole and the water hole of the core; a rotor made with a cylindrical magnetic material and inserted into the core; cylindrical support rings forcedly fit to both sides of transfer shafts of the rotor; a pair of bearings respectively disposed at the front side and the rear side of the support rings; a coupling disposed in front of the rotor; a front housing joined to the front of the outer housing; a front cap disposed at the rear of the core; a rear cap disposed at the rear of the front cap and having a power supply terminal disposed at one side thereof; and a rear housing joined to the rear of the outer housing.

The present invention relates to a direct cooling type handpiece, and more particularly, to a direct cooling type handpiece that is configured to allow an outer housing and a core to be spaced apart from each other and thus to allow the core to be fixed to a PCB and a support cap, so that air flows to the space between the outer housing and the core, thus efficiently cooling the high heat generated from the handpiece while the handpiece is being operated.

The present invention relates to a direct cooling type handpiece, and more particularly, to a direct cooling type handpiece that is configured to allow an outer housing and a core to be spaced apart from each other and thus to allow the core to be fixed to a PCB and a support cap, so that air flows to the space between the outer housing and the core, thus efficiently cooling the high heat generated from the handpiece while the handpiece is being operated.

The invention relates to a dental preparation instrument that includes a tool that rotates in an alternately reversible manner. The preparation instrument has a drive for the tool. The drive provides a continuous fully rotational motion, and a gearing is arranged before the tool. Said gearing converts the continuous fully rotational motion of the drive into an alternately reversing rotational motion, which is continuous as viewed over several reversals.

The invention relates to a dental preparation instrument that includes a tool that rotates in an alternately reversible manner. The preparation instrument has a drive for the tool. The drive provides a continuous fully rotational motion, and a gearing is arranged before the tool. Said gearing converts the continuous fully rotational motion of the drive into an alternately reversing rotational motion, which is continuous as viewed over several reversals.

Apparatus is provided that includes a surgical tool for use with solid particles and a physiological liquid solution. The surgical tool includes (a) a shaft unit, which is shaped so as to define a delivery lumen, and a distal opening, which is disposed within 10 mm of a distal end of the shaft unit, in fluid communication with the delivery lumen; (b) a composition source, which is coupled in fluid communication with the delivery lumen, and which is configured to provide a solid-liquid composition of the solid particles and the physiological liquid solution; and (c) a pump, which is configured to pump the solid-liquid composition through the distal opening via the delivery lumen.

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.