Abstract
An endodontic file, for manual or motor driven use by an endodontist, includes a color-coded handle, a shank, and a serrated cutting edge. The cutting edge of the endodontic file is side-cutting with pyramidal teeth and ends in a pointed tip. The endodontic file is used manually inside the root canal in an “up and down” axially aligned motion and these pyramidal teeth will provide a ripping action. A second type of endodontic file has a curved cross section and a sharpened tip. with pyramidal teeth lining the edges of curved blade section. A third type of endodontic file has a flat debriding side which tapers to a point; with a series of adjacent 3-D pyramids emerging from this surface for removing loose material or in urging already loosened material from a root canal.
Claims
1. A method of clearing a root canal in preparation for retreatment comprising the steps of: inserting into said root canal a debriding section of an endodontic re-treatment instrument, said instrument comprising a handle adapted for manual manipulation without use of power, said debriding section, and a shank connecting said handle to said debriding section, said debriding section comprising a flat side not having any cutting edges and an upper edge having sharp saw tooth denticulated projections along a side opposite to said flat side, with each sharp saw tooth denticulated projection extending upward; and moving said instrument manually within said root canal for engaging a gutta percha sleeve surrounding a central carrier core therein, cutting away the gutta percha sleeve without damaging the carrier core, then said carrier core is released from said root canal, permitting removal of the carrier core therefrom the root canal.
2. The method of claim 1 in which said handle is manually manipulated causing said debriding section to move in upward, downward and/or sagittally and/or transversely within said root canal.
3. The method of claim 2 in which each said sharp saw tooth denticulated projection comprises two or more sides extending up from a lower blade-supporting portion and converging to a top apex.
4. The method of claim 3 wherein said two or more sides of said sharp saw tooth denticulated projections are linear, converging to said apex.
5. The method of claim 4 wherein said linear converging sides of said sharp saw tooth denticulated projections converge to an apex cutting point.
6. The method of claim 5 wherein said linear converging sides of said sharp saw tooth denticulated projections converging to an apex cutting point are a single row of three-dimensional pyramidal teeth each tapering to a point at a top thereof.
7. The method of claim 6 wherein each of said three dimensional pyramidal teeth comprise four triangular side faces coming to a point whereby said upper edge comprises a plurality of spaced pointed tops of said pyramidal teeth.
8. The method of claim 1 in which said saw tooth denticulated projections comprise isosceles triangular shaped teeth in profile, and where each said tooth has a forward facing side edge that extends at a vertical angle from said flat side.
9. The method of claim 1 in which said debriding section tapers to a narrowed distal end.
10. The method of claim 1 wherein said shank and debriding section are orthogonal to its length.
11. The method of claim 10 in which a distal end of said debriding section is ground to a sharp cutting edge.
12. The method of claim 1 wherein said shank is cuboid in shape.
13. The method of claim 1 having evenly high sharp saw tooth denticulated projections.
14. The method of claim 1 having said sharp tooth denticulated projections of variable levels.
15. The method of claim 1 in which said sharp tooth denticulated projections have pointed tops.
16. The method of claim 1 in which said instrument is made of stainless steel.
17. The method of claim 1 in which said instrument is made of nickel titanium.
18. The method of claim 1 wherein said sharp saw tooth denticulated projections are triangular, have concave valleys therebetween, said instrument having a width of between 0.10 mm and 0.50 mm, a length of between about 20 mm and 30 mm and a vertical height of between 0.40 mm and 0.75 mm, excluding a handle or motor driven adaptor at a proximal end thereof.
19. The method of claim 1 wherein said sharp saw tooth denticulated projections are triangular, have a concave valley therebetween, said instrument having a width of about 0.25 mm, a length of about 25 mm and a vertical height of about 0.57 mm.
20. A method of clearing a root canal in preparation for retreatment comprising the steps of: inserting into said root canal a debriding section of an endodontic re-treatment instrument, said instrument comprising a handle adapted for manual manipulation without use of power, said debriding section, and a shank connecting said handle to said debriding section, said debriding section comprising a straight, partially tubular member with a C-shaped cross section orthogonal to its length, having spaced and facing parallel edges along a length thereof and joined by a sharp distal end, and said debriding section having sharp saw tooth denticulated projections extending along at least a portion of said spaced and parallel edges; and manipulating only manually said instrument within said root canal for engaging a gutta percha sleeve surrounding a central carrier core therein, cutting away the gutta percha sleeve without damaging the gutta percha carrier core, then said carrier core is released from said root canal, permitting its removal therefrom.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The present invention can best be understood in connection with the accompanying drawings. It is noted that the invention is not limited to the precise embodiments shown in the following drawings, in which:
(2) FIG. 1 is a perspective view of a P-file of this invention.
(3) FIG. 2 is a close-up detail perspective view of the P-file of FIG. 1, taken along circular view line “2” of FIG. 1, showing some cutting teeth which each extend to a respective single point cutting pinnacle point, where the cutting blade is supported by and positioned adjacent to a preferably mainly cuboid shank support, which is insertable into a handle.
(4) FIG. 3A is a perspective detail view of a cutting blade teeth and support portions of triangular shaped saw teeth, which have planar sides which are co-terminus with the sides of the cutting blade support portions, where the top cutting edges of the saw teeth extend linearly, but not as wide as the base of the support portions, where the saw teeth and support portions are coterminous with each other and slanted upward from a base which is wider than the apex of the saw teeth.
(5) FIG. 3B is a top plan view of the cutting blade and blade support portion of FIG. 3A.
(6) FIG. 4A is a close-up perspective view of an alternate embodiment for an endodontic file with 3-D pyramidal shaped debriding teeth.
(7) FIG. 4B is a top plan view of the endodontic file of FIG. 4A.
(8) FIG. 5A is a side perspective view of a further alternate embodiment for a “corer” endodontic file with pyramidal teeth on both file edges of a hollow half cylindrical two-sided cutting blade, having a hollow region between the arcuate file cutting saw blade edges, forming a curved “C-shape” cross sectional configuration.
(9) FIG. 5B is a close-up perspective view of the embodiment shown in FIG. 5A, taken along circular view line “5B” of FIG. 5A.
(10) FIG. 6 is a perspective view of a tooth being debrided using a P-file to remove the gutta-percha (GP) surrounding a central carrier core in a root canal.
(11) FIG. 7 is a perspective view of the result of the procedure of FIG. 6 with the gutta percha (GP) broken down and the central carrier core shown removed from the root canal.
(12) FIG. 8A shows a design for file teeth with a curved valley extending in the nadir between one tooth to an adjacent tooth.
(13) FIG. 8B is a close-up detail side elevation of file teeth with a curved valleys shown in FIG. 8A.
(14) FIG. 9 is a side elevation of the distal end of an endodontic file having all teeth at the same level.
(15) FIG. 10 is a side elevation of the distal end of an endodontic file having teeth at different levels.
(16) FIG. 11 is a side elevation of an endodontic file having hyperbolic, non-linear shaped cutting saw teeth.
(17) FIG. 12 is a side elevation of an endodontic file having non-linear shaped cutting saw teeth, based upon inverse parabolas, but with a pointed apex.
(18) FIG. 13 is a side elevation showing an endodontic file with triangular teeth on both edges.
(19) FIG. 14 is a side elevation view of another embodiment for an endodontic file, showing critical dimensions.
(20) FIG. 15 is a perspective view from below of the endodontic file of FIG. 14, also showing critical dimensions.
(21) FIG. 16 is a perspective view of a powered handpiece driving an endodontic file.
DETAILED DESCRIPTION OF THE DRAWINGS
(22) FIGS. 1 and 2 illustrate two views of P-file 1 with handle 7, shank 5 on metal portion, and a debriding cutting blade 3, with denticulated projections, such as pyramidal cutting teeth, which are preferably flat but with triangular shaped profiles, when viewed in side elevation views. The teeth of debriding cutting blade 3 are used for removing from debris within a tooth, such as pulp and nerve tissues in an original endodontic root canal procedure or to remove gutta percha and debris from a previously treated root canal, so that a centrally located carrier core can be removed, without damage to its integrity, during the re-treatment of the root canal.
(23) FIGS. 1 and 2 show the preferred embodiment where the cutting teeth of debriding cutting blade 3, are shown bearing isosceles triangular shapes in profile, and where the teeth have a forward facing side face that extends vertically, coterminous with the flat, also vertically extending blade support member portion of the blade below the teeth. The pinnacle point of each tooth 3 of the cutting blade of the endodontic file 1 is a single geometric point, as opposed to a linear extending cutting portion of FIGS. 3A and 3B, where in FIG. 2 the respective sides and rear of the saw teeth converge at the pinnacle point. The shank 5, from which the cutting saw blade 3 extends, preferably has a cuboid cross section, with perpendicular sides and top and bottom, which is stronger to support the cutting blade 3 of sharp saw teeth. Cuboids such as shank 5 are convex polyhedrons which have six faces with edges, where adjacent faces are perpendicular to other adjacent faces of the polyhedron.
(24) In one alternate embodiment, FIGS. 3A and 3B the respective cutting blade portion 3 has triangular-shaped saw teeth 3a having sharp top edges 3b, lower valley depth regions 3c, flat side facets 3d and lower blade support portions 3e. The saw teeth 3a's planar sides are co-terminus with the planar sides of the blade support portions 3d, where the top cutting edges 3b of the saw teeth 3a extend linearly, but not as wide as the base of the blade support portion 3e, where the saw teeth 3a and blade support portion 3e are coterminous with each other and slanted upward from a lower base of blade support portion 3e, which is wider than the apexes 3b of the saw teeth 3a, so that in the view of FIG. 3A, the cross sectional end of the cutting blade portion 3 is trapezoidal in shape. It is further noted that even when the endodontic cutting file of FIGS. 3A and 3B is very thin, the linearly extending cutting edges 3b of the saw teeth 3a can present themselves as almost pointed pinnacles, where each side of the cutting blade portion 3 are separated from the other side by the tiny linearly extending cutting edges 3b of the saw teeth 3a. Furthermore, while the cross sectional ends of the cutting blade portion 3 are shown as trapezoidal, they can also alternatively present themselves as vertically extending side edges of a cutting blade portion with saw teeth 3a and top cutting edges 3b.
(25) The perspective detail view of another alternate embodiment for a three-dimensional endodontic file 11 in FIG. 4A shows an endodontic file with shank 5 and a debriding section member 13 with three dimensional (3-D) pyramidal teeth 13a tapering to a point 13b. The teeth 13a in the form of 3-D pyramids emanate from a flat blade support base 13c in forward debriding section member 13, are shown more clearly from above in FIG. 4B. While FIGS. 4A and 4B show classical four-sided pyramid shapes for the cutting teeth 13a, it is known that other non-traditional pyramid shapes may be presented with three sides, or more than four sides, emanating into a top pinnacle point 13b.
(26) The endodontic instrument 1 of FIGS. 1, 2, 3A and 3A, and the instrument 11 of FIGS. 4A and 4B, can either have a handle for manual rotation and cutting by the endodontist, or can be attached to a power tool 41 in a motor driven version, such as shown in FIG. 16.
(27) FIGS. 5A and 5B show a perspective view of a further alternate embodiment for a “corer” endodontic file 17 of this invention. The metal cutting section 19 is straight with a curved cross section orthogonal to its length. The top portion that is engaged with handle 7 is the shank which is also curved but has no cutting teeth. Pyramidal cutting teeth 21, similar to teeth of the cutting blade 3 of the embodiment of FIGS. 1-2, or of the teeth 3a of the embodiment in FIGS. 3A and 3B, are formed on the axial edges of the forward section of metal cutting section 19. The distal end 23 of the cutting section 19 is ground to a sharp cutting distal end. In use, file 17 is moved up and down and rotated in clockwise or counterclockwise directions 25, in either direction. The corer endodontic file 17 is therefore a straight, partially tubular member with a C-shaped cross section orthogonal to its length, having spaced and facing parallel edges along at least a part of a length of cutting section 19 and joined by the sharp distal end 23. The debriding section member includes sharp saw tooth denticulated projections 21 extending along at least a portion of the parallel edges of the straight partially tubular member 19, with the C-shaped cross section. The extended C-shaped endodontic instrument 17 of FIGS. 5A and 5B, can either have a handle for manual rotation and cutting by the endodontist, or can be attached to a power tool in a motor driven version, such as power tool 41 of FIG. 16.
(28) Furthermore, FIGS. 6 and 7 illustrate some of the method involved in debridement as part of the retreatment process. In FIGS. 6 and 7, a partial tooth 33 with a side sliced to reveal three root canals below the gum 31 line, is shown. FIG. 6 shows a P-file 1 reciprocating while engaged with the obturating gutta percha (GP) annular seal 36 around the edge of plastic carrier core 35. The objective is to free root canal 39 of the obturating gutta percha 36 and plastic carrier core 35 as shown in FIG. 7. Therefore, the main goal of the endodontist in re-treating this kind of obturation material in the carrier core 35 (carrier-based obturation materials) is to maintain the carrier 35 as intact as possible, for easy retrieval, by indirectly digging into and removing the gutta percha material 36 surrounding the carrier 35 with the endodontic files 1, 11 or 17 of the present invention, without causing torsional fatigue and possible damage with a wide rotating instrument, but without the complexities of re-treatment with rotary files. By using the thin saw-blade teeth and thin cross-section of the cutting part, the endodontic files 1, 11 or 17 can fit and dig into the confines of the gutta percha 36 located between the carrier 35 and the dentin wall of tooth 33, while ripping through the surrounding gutta-percha 36 without potentially damaging the carrier 35, which is something the prior art rotary files cannot do without difficulty, owing to their wider, rounded cross-section and break susceptible rotary fluting.
(29) FIGS. 8A, 8B, 9, 10, 11, 12 and 13 show alternate embodiments for different geometric shapes for the saw teeth denticulated projections.
(30) For example, FIG. 8A shows an enlarged design for an endodontic file having triangular teeth 50 with a concave curved valley 52 located at the nadir between adjacent teeth 50. The actual file teeth of FIG. 8A are shown in FIG. 8B as teeth 54, also with concave curved valleys 52 located at the nadirs between adjacent teeth 54.
(31) In the embodiment of FIG. 9, the distal end 56 of an endodontic file (enlarged) with evenly high teeth 58 are shown, which are not equal sided isosceles triangles.
(32) In the embodiment of FIG. 10, the enlarged distal end 60 of an endodontic file having teeth of variable levels 62 is shown.
(33) FIG. 11 shows an endodontic file tooth profile in which saw teeth denticulated projections 64 are hyperbolic in shape. In this embodiment, the endodontic file can optionally have parabolic-shaped saw teeth 64 adjacent to one another, where instead of linear sides extending upward towards an apex point, as in FIGS. 1-5 and 8-10, the sides of saw teeth 64 would be extending upward and converging in curved lines towards a tangent to a curve, as in a parabola.
(34) FIG. 12 shows an endodontic file tooth profile, similar to FIG. 11 in which saw teeth 64 are hyperbolic in shape. But in FIG. 12, the endodontic file can optionally have curved, arcuate-shaped saw teeth denticulated projections 64a adjacent to one another, where the curved arcuate sides extending upward towards an apex point 64b. Therefore, the sides of saw teeth 64a would be extending upward and converging towards a sharp apex point 64b. While the saw teeth in FIG. 11 form a parabola, in FIG. 12 the sides of each saw teeth are one half of a downwardly extending parabola, so that the curved sides meet at a pointed apex.
(35) Therefore, in general, the saw teeth comprise two or more sides converging to a top apex point or region. When the converging sides are linear converging to an apex, as in FIGS. 1-4B and 8A-10, the shape of each saw tooth is that of a triangle, either equilateral or non-equilateral. If the converging sides are curved and arcuate, converging to a curved or pointed apex, as in FIGS. 11 and 12, then the shape of each saw tooth 64 and 64a of the blade is that of a parabola, as in FIG. 11, or of adjacent sides of an inverse parabola, as in FIG. 12.
(36) FIG. 13 shows an embodiment for a double-sided cutting endodontic file 66 having triangular teeth 68 on both edges.
(37) FIGS. 14 and 15 illustrate two views of an endodontic file 71 (with handle not shown), cuboid shaped shank 75 on a metal portion, and cutting blade 73 having triangular cutting teeth 74 bearing isosceles triangular shapes in profile, where the teeth 74 have a forward facing side face that extends vertically, coterminous with the flat, also vertically extending shank support portion of the blade 73 below the teeth 74. Each tooth 74 of the cutting blade 73 of the endodontic file 71 has a sharp cutting point or region 74a. The shank 75 has a cuboid cross section. FIG. 14 also shows the endodontic file 71 having triangular teeth 74, but with a curved concave valley 74b between adjacent triangular teeth 74. Concave valley 74b is equivalent to the concave valley is identified as reference numeral “52” in drawing FIGS. 8A and 8B.
(38) While dimensions may vary, in a preferred embodiment shown in FIGS. 14 and 15, the linear measurements are shown therein in millimeters. Therefore the length of endodontic file 71 is about 25 mm (0.984 inches) and the height at the proximal rear edge is about 0.57 mm. Additionally, the length of the cuboid shank 75 is about 9 to 9.33 mm, leaving the blade length of cutting blade 73 to be about 15.67 to 16 mm. The 54.66-degree angle shown in FIG. 14 refers to the angle between the last sloping edge of the saw teeth 74, as against the beginning front edge of the shank 75. The angle of 169.82 degrees, located at the distal cutting edge, refers to the angle from the horizontal bottom of cutting blade 73 to the initial slope of the distal portion 73a, before the first of the cutting teeth 74. The 79.14 degree angle represents the angle of the valley between a saw tooth 74 and its next adjacent saw tooth 74.
(39) The number “R0.09” refer to length in millimeters of the radius of the small concave portion 74b in the depth of the respective valleys between each successive triangular silhouette shaped saw teeth 74.
(40) The endodontic re-treatment instrument 71, is shown in an alternate embodiment, with sharp saw tooth denticulated projections 74, which are triangular in shape, having concave curved valleys 74b therebetween. The re-treatment instrument 71, can have a width extending in a range of between 0.10 mm and 0.50 mm, a length extending in a range of between about 20 mm and 30 mm and a vertical height extending in a range of between 0.40 mm and 0.75 mm, excluding a handle or motor driven adaptor at a proximal end thereof.
(41) While dimensions may vary, because the example shown in FIGS. 14 and 15 has a width of only between 0.10 mm and 0.50 mm, preferably about 0.25 mm, along its length, it can easily dig into the three areas of gutta percha thicknesses described previously in Alhashimi et al, where the thicknesses of 0.376, 0.357 and 0.591 provide ample room for insertion of the endodontic file of FIGS. 14 and 15 with its thin thickness preferably of only 0.25 mm, or within the range of between 0.10 mm and 0.50 mm. While it would be too thick to be inserted at the gutta percha thickness of only 0.164, removal of three quarters of the gutta percha at the thicker thickness of 0.376 mm, 0.357 mm and 0.591 mm will enable the thinnest part to crumble by removal of its adjacent thicker portions exceeding the preferable 0.25 mm thickness of the endodontic file shown in FIGS. 14 and 15.
(42) Generally, the deepest any endodontic re-treatment file tool can reach inside the root canal being re-treated is the best. For endodontic instrument with saw tooth denticulated cutting projections, of the present invention, reaching just halfway will be enough (average of 8-10 mm) to dig into and breakup the gutta percha to be removed from a tooth root canal of approximately 16-20 mm in length. However, in certain circumstances where the canal is straight, as opposed to curved at the apical end, yet, it can get into the full length of the canal owing to its design and thickness.
(43) While the aforementioned new endodontic files introduced by this invention have been shown with handles for manual use, they can be powered. FIG. 16 shows a powered handpiece 41 comprising handpiece handle 43, power unit 45, and one of the three files of this invention (minus handles) chucked in power unit 45. The power unit can have the capability to follow the motions indicated by arrows 47, straight up and down, rotary in either direction, or alternate circular motion.
(44) A preferred embodiment for a motor driven handpiece uses the prior art motor driven apparatuses of W & H DentalWerks of Germany for cutting jaw bones may be adapted for orthodontic rework. Their S-8 series supports sagittal, oscillating, or reciprocating movement.
(45) For example, while the three new endodontic files introduced by this invention have been shown with handles for manual use, they can be powered. FIG. 16 shows a powered handpiece 41 comprising handpiece handle 43, power unit 45, and one of the various files of this invention (minus handles) chucked in power unit 45. The power unit can have the capability to follow the motions indicated by arrows 47, axially straight up and down, rotary in either direction, alternate circular motion, or combinations thereof.
(46) Although the aforementioned U.S. Pat. No. 4,353,698 of McSpadden cited above is for use in obturating stripped root canals and not debridement, similar powered rotary tools with similar working ends are used in debridement today. With the use of plastic carriers surrounded by gutta percha (GP) or similar obturating material in a root canal undergoing retreatment, debridement including removal of the plastic carrier more often results in unwinding and separation of retreatment files (ProTaper). Two retreatment files of this invention may be better suited as powered working ends. One version is the generally thin P-file 1 of FIGS. 1 and 2, 3A and 3B, the P-file 11 of FIGS. 4A, 4B, the double sided file of FIG. 13, or the file 71 of FIGS. 14 and 15. Another version is the “corer file” of FIGS. 5A and 5B when sized with a cross section inner radius slightly larger than the outside diameter of the plastic carrier. These files would be moved in a compound fashion, reciprocating for active cutting away gutta percha, while rotating slowly (or in small discrete steps) around the carrier core for removal without damage by pulling from above with an instrument, such as a tweezer or other grasping hand tool. The instrument's path followed would be similar to that illustrated in FIG. 6, for removal of the outer gutta percha sheath 36 and central carrier core 35 The carrier core 35 is removed from root 39 intact, without damage to carrier core 34, as shown in FIG. 7.
(47) In the foregoing description, certain terms and visual depictions are used to illustrate the preferred embodiment. However, no unnecessary limitations are to be construed by the terms used or illustrations depicted, beyond what is shown in the prior art, since the terms and illustrations are exemplary only, and are not meant to limit the scope of the present invention.
(48) It is further known that other modifications may be made to the present invention, without departing the scope of the invention, as noted in the appended Claims.
