Abstract: Instrument for the treatment of the apical portion of radicular dental canals, has a conical shaft (1) having at least one helicoidal working ridge. The active anterior portion (2) of the instrument is comprised of at least two successive cones whose opening (,X) decreases from the anterior point (3) of the instrument in the direction of its active posterior portion.

Abstract: Instrument for the treatment of the apical portion of radicular dental canals, has a conical shaft (1) having at least one helicoidal working ridge. The active anterior portion (2) of the instrument is comprised of at least two successive cones whose opening (X) decreases from the anterior point (3) of the instrument in the direction of its active posterior portion.

Abstract: Instrument for the treatment of the apical portion of radicular dental canals, has a conical shaft (1) having at least one helicoidal working ridge. The active anterior portion (2) of the instrument is comprised of at least two successive cones whose opening ( ,X) decreases from the anterior point (3) of the instrument in the direction of its active posterior portion.

Abstract: Instrument for the treatment of the apical portion of radicular dental canals, has a conical shaft (1) having at least one helicoidal working ridge. The active anterior portion (2) of the instrument is comprised of at least two successive cones whose opening (,X) decreases from the anterior point (3) of the instrument in the direction of its active posterior portion.

Abstract: Instrument for the treatment of the apical portion of radicular dental canals, has a conical shaft (1) having at least one helicoidal working ridge. The active anterior portion (2) of the instrument is comprised of at least two successive cones whose opening (,X) decreases from the anterior point (3) of the instrument in the direction of its active posterior portion.

Abstract: Instrument for the treatment of the apical portion of radicular dental canals, has a conical shaft (1) having at least one helicoidal working ridge. The active anterior portion (2) of the instrument is comprised of at least two successive cones whose opening (&bgr;,X) decreases from the anterior point (3) of the instrument in the direction of its active posterior portion.

Abstract: An instrument for boring dental radicular canals in which the conicity of the active part of the tapered stem of the instrument is not constant but the angle of its opening is greater at its rear portion, positioned beyond the diameter D.sub.9, than the angle of opening of its front portion positioned between its end and the diameter D.sub.9 so that a dental canal bored with the instrument has a bell-mouthed shape.

Abstract: A set of instruments for boring of radicular dental canals, in which the diameter D1 of each instrument, measured at the root of the pointed end portion thereof, varies according to a geometrical progression as well as the diameter D2 of each instrument measured at the root of the cutting edges. Hence, the variation is more pronounced for the diameters D2, larger than the diameters D1, than it is for the diameters D1. The conicity of the stem of the instruments increases in this manner from one instrument to another, so as to permit a the dentist to form the radicular canals with a specially funnelled shape which is best suited for some obturations, especially those to be treated with gutta-percha.

Abstract: A set of instruments for boring dental radicular canals in which the conicity of the rear part of the set positioned beyond the diameter D.sub.9 of the instruments, increases more for the first instruments of the set than for the last ones. The conicity of the front part of the instruments does not increase much for the first instruments of the set, but does increase for the last ones. Hence, while using successively the instruments of a set, the dentist bores first the coronary portion of the tooth, then its medium portion and then its apical portion. The end part of the instruments, between the point thereof and their diameter D.sub.3, situated at 3 mm from the point, is provided with one or several grooves for elimination of the dental scraps, but which have no cutting edges so that this part of the instruments functions only for their guidance.

Abstract: In connection with implant work on the dentine, a machining instrument is used which is provided with an attachment part for attachment to a rotary unit or for attachment to extension unit, which in turn can be applied to the rotary unit. The extension unit has a thickened central section which is provided with a recess or opening in which an inclined surface is arranged. In the applied position of a machining instrument, one surface of its attachment part is set against the inclined surface of the extension unit. The extension unit and the machining instrument are rotationally-fixed with respect to each other. Moreover, a locking effect is achieved between the extension unit and the machining instrument as a result of a secure wedging effect obtained by means of the inclined surface.

Abstract: The end of an instrument for the treatment of dental root-canals is coated with a layer of anti-friction material. The low coefficient of friction of the antifriction material and the fact that it renders the end of the instrument non cutting or non abrasive facilitates greatly the penetration of the instrument in the dental root-canal, especially when the canal is curved, and has the result that the instrument does not bite into the wall of the canal and does not exert thereon an action which is greater on the outside of the curve than on the inside thereof.

Abstract: The stem is tubular, being provided with an axial bore and is frusto-conical. It is provided with an outer thread as well as with a helical groove which provides therefor a resiliency enabling its section to adapt itself perfectly to the section of the root canal in which the pin is screwed.