Endodontic instrument
AssigneeSybron Corporation
InventorsWilliam A. Groves, Frank N. Lentine
Life of this patent
Estimating the term…
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..
Claims13
In an Endodontic Instrument for use in root canal preparation including an axially tapered flexible rod for insertion into the root canal, said rod having spiral faces defining spiral edges between them and a handle portion fixed to the rod for manipulating the endodontic Instrument, the improvement comprising:
- said rod having a tetragonal cross section, the sides of which are substantially flat and define at least one obtuse angle and one acute angle, the spiral edge corresponding to each acute angle being a cutting edge.
An endodontic instrument comprising:
- (a) a handle for manipulating the instrument;
- (b) a tapered file extending from said handle, said file in cross section being generally the shape of an oblique parallelogram having a major diagonal and a minor diagonal;
- and
- (c) said file being axially twisted over at least a portion of its length to provide two spiral cutting edges at the ends of said major diagonal which alternates with two spiral edges at the ends of said minor diagonal.
A method of making an endodontic instrument comprising the steps of:
- (a) grinding an elongaged tapered rod to provide a generally parallelogram cross section for at least a portion of its length, said parallelogram cross section having opposite obtuse angles, a major diagonal and a minor diagonal;
- (b) axially twisting said rod after grinding to provide four spiraling edges, two of said edges defining the major diagonal alternating with two of said edges defining said minor diagonal;
- and
- (c) fixing one end of said rod to a handle for manipulating said instrument.
An endodontic cutting instrument comprising:
- (a) an elongated, axially twisted tapered rod, said rod being sufficiently flexible to follow the root canal;
- (b) said rod in cross section being the shape of an oblique parallelogram with two obtuse angles and two acute angles;
- and
- (c) the edges of said rod corresponding to the acute angles of said oblique parallelogram cross sectional shape being the cutting edges of said instrument.
Dependencies are inferred from the claim text.