Abstract: A series of multi-tapered parabolic implements is disclosed for endodontic use. The instruments comprise different sections: a pilot tip, a first portion adjacent the pilot tip and a second portion adjacent the shank. The two portions have different tapers. The tapers of the two different portions blend into each other along a parabola-shaped surface. The pilot tip is radiussed for ease of entry into a root canal with increased safety.

Abstract: A rotatable endodontic file for cleaning/shaping a tooth root canal, comprising: an elongated shaft having a proximal end portion, a distal end and a tapered working portion having a rotational axis, the working portion extending from said proximal portion to said distal end; the external surface of said shaft working portion having a plurality of at least two spirals, a parallelogram-shaped cross section that has an axis of rotation that is asymmetric such that the center of mass (centroid) is not along the file axis.

Abstract: Endodontic instruments are described which have at least a section with a center of mass offset from an axis of rotation so that when the instrument is rotated, the section bends away from the axis of rotation.

Abstract: A medical drill is disclosed, which is made of amorphous alloy, the amorphous alloy is zirconium amorphous alloy comprising 45 at % or above of zirconium, wherein the tensile strength of the medical drill is 1500-2500 Mpa, and the Vicker's hardness of the medical drill is 400-750. Moreover, a medical drill made of titanium amorphous alloy is also disclosed.

Abstract: An anchor installation tool has an elongated driving member with a body portion and a head portion. A retaining mechanism retains the anchor installation to the drill bit. The mechanism has a housing on the body portion with a pair of bias lugs that project through the body portion to contact the drill bit. An anchor guide slides on the body and head portion and has a holding member to hold an anchor. The anchor is held in the anchor guide and a drill bit is inserted into the driving member. Axial movement of the drill bit is transferred into axial movement of the driving member. The movement strikes the anchor and ejects the anchor from the anchor guide into a surface.

Abstract: An endodontic instrument and method of manufacturing an instrument including an elongate member having a longitudinal axis, a proximal end, a distal end and a working length between the proximal and distal ends. The working length is formed with a plurality of surface portions ground from the outer surface thereof along paths extending along the longitudinal axis. One or more edges formed during the initial grinding operations are then at least partially ground down. The ground blank is then physically twisted to form helical cutting and/or debris removal edges extending around the longitudinal axis. The instrument may be a file or reamer used in root canal procedures and may have three, four or more longitudinally extending surface portions and multiple edges. Flexibility of the instrument may also be easily varied according to the invention.

Abstract: A compost aerator and monitor which has a cylindrical helical screw, preferably with a sharpened first end. The diameter of the cylindrical helix and the tightness of the windings are selected so as, when the screw is inserted into a compost pile, to create a core of compost material that is sufficiently large to be cohesive and representative but not so large that the weight of the core will cause the core to fall from the screw when such screw is withdrawn from the compost pile. Attached to the second end of the screw is a handle with sufficient leverage to enable the screw to be turned rapidly and, consequently, rapidly introduced into a compost pile and to preclude the screw from rotating as the screw is withdrawn from the pile, thereby retaining the core of compost material. Optionally, either a traditional brace or a traditional power drill can replace the simple handle; and a shaft can be inserted between the screw and the handle or the brace.

Abstract: An endodontic instrument formed by twisting a tapered blank which in cross section is ground to an oblique parallelogram, the obtuse angles of the oblique parallelogram cross section being between 105.degree.-120.degree..

Abstract: A flute piece consisting of a piece of tungsten carbide twisted or formed such that the flute piece has at least two helical cutting edges and an axis through which the tungsten carbide material extends. The flute piece is intended for an engineers' tool for working ferrous or non-ferrous metal, plastics or wood, such as a twist drill or a milling or boring cutter for a machine tool. A shank member has an extension web on one end thereof which is provided with a helical slot for reception of the flute piece.