JP4740294B2 - Cutting bar set and broken piece removal method - Google Patents

Description

  The present invention relates to a method for removing broken pieces of a root canal treatment instrument left in a root canal, and a cutting bar set used therefor.

  In root canal treatment, root canal treatment instruments such as files used for enlarging the root canal are derived from the work of cutting dentin, dentin, pulp tissue, etc. Is easily predicted. Therefore, it is ideal to dispose of the equipment for each patient to be treated, but in practice it is generally repeated every time the equipment is cleaned and sterilized, and it is used continuously until it is functionally unbearable. It was the target. On the other hand, since the device is continuously used, the tip of the device is often broken during the treatment, and broken pieces remain in the root canal.

In the past, instruments and methods for removing such broken pieces have been developed (see, for example, Patent Document 1 and Patent Document 2), and there is a problem that broken pieces of root canal treatment instruments remain in the root canal. Has been addressed.
Japanese Patent No. 3594867 Japanese Patent No. 3597158

  The present invention provides a method for reliably removing a broken piece of a root canal treatment instrument left in the root canal by a simple operation without excessively or unnecessarily shaving the root canal wall, and It aims at providing the broken piece removal set used for it.

  The cutting bar set of the present invention is a set for removing broken pieces of a root canal treatment instrument left in the root, and includes a first cutting bar for cutting the root canal wall, a root canal wall, and / or Or the 2nd cutting bar which cuts the crown side of the fractured piece of the root canal treatment instrument left in the root canal, and the tooth of the fractured part of the root canal treatment instrument left in the root canal wall and / or the root canal A third cutting bar that cuts off a crown side, wherein the first cutting bar includes a metal rod, a first guide portion that protrudes from a distal end of the metal rod, and the first guide portion. A first blade provided on a side surface of the proximal portion and oriented perpendicularly to the metal bar, the second cutting bar projecting from the metal bar and a distal end of the metal bar A second guide portion, and a proximal portion of the second guide portion; The third cutting bar includes a metal bar, a cylinder provided at a distal end of the metal bar, and an edge of a tip of the cylinder, the metal bar And a third blade oriented in the tip direction. In the broken piece removal set, the length of the first guide part is preferably 0.35 mm or more and 1.75 mm or less, and the width of the distal end of the first guide part is 0.10 mm. The length is preferably 0.50 mm or less, and the length of the second guide portion is preferably shorter than the length of the first guide portion. Moreover, it is preferable that the outer diameter of the said metal bar in the distal end of the said metal bar is 0.50 mm or more and 0.70 mm or less. Moreover, it is preferable that the width | variety from the outer wall of a said 2nd guide part to the outer wall of a said 2nd blade is 0.25 mm or more. The outer diameter of the cylinder is preferably 0.50 mm or more and 0.70 mm or less, the inner diameter of the cylinder is preferably 0.33 mm or more and 0.50 mm or less, and the length of the cylinder is 0.00. It is preferable that it is 40 mm or more and 1.20 mm or less.

  Furthermore, the broken piece removal set of the present invention may include a hooking device having a loop-shaped wire for removing the broken piece cut by the third cutting bar outside the root canal.

  The method for removing a broken piece of the present invention is a method for removing broken pieces of a root canal treatment instrument left in a root canal, and a method for removing a broken piece of a root canal treatment instrument left in a root canal. A first step of cutting the root canal wall to a depth to reach, a second step of cutting the crown side of the fractured piece into a cylindrical shape, and a second step of removing the fractured piece cut in the second step outside the root canal And 3 processes. In the first step, a metal rod, a first guide portion protruding from a distal end of the metal rod, and a side surface of a proximal portion of the first guide portion, the metal rod being vertical A cutting bar comprising a first blade oriented in the direction may be used. Further, in the second step, a metal rod, a tube provided at a distal end of the metal rod, and a third blade provided at an edge of a tip portion of the tube and facing the tip direction of the metal rod A cutting bar equipped with the above may be used. In the third step, an instrument for hooking the broken piece onto a wire may be used.

  According to the present invention, there is provided a method for reliably removing a broken piece of a root canal treatment instrument left in the root canal by a simple operation without excessively or unnecessarily shaving the root canal wall, and It has become possible to provide a debris removal set for use therein.

  The objects, features, advantages, and ideas of the present invention will be apparent to those skilled in the art from the description of the present specification, and those skilled in the art can easily reproduce the present invention from the description of the present specification. Embodiments and the like of the invention described below show preferred embodiments of the present invention, and are shown for illustration or explanation, and the present invention is not limited thereto. It will be apparent to those skilled in the art that various modifications and variations can be made based on the description of the present specification within the spirit and scope of the present invention disclosed herein. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

=== Configuration of Broken Piece Removal Set ===
The broken piece removal set of the present invention includes a broken piece cutting device 300 and a broken piece removing instrument 400. Hereinafter, the broken piece cutting apparatus 300 and the broken piece removing instrument 400 will be described in detail.

(1) Broken piece removal apparatus 300
The configuration of a broken piece cutting apparatus 300 according to an embodiment of the present invention is shown in FIG.
The broken piece cutting apparatus 300 includes a cutting bar 100 and a cutting bar mounting tool 200 for mounting the cutting bar.

(1-1) Cutting Bar Set The cutting bar set of the present invention includes first to third cutting bars 100 which are instruments for cutting root canals and broken pieces. It is preferable to use the cutting bar 100 having an appropriate size and length depending on the state of a broken piece of a root canal treatment instrument such as a reamer or a file left in the root canal. A specific configuration is shown below.

(I) 1st cutting bar The schematic structure of the 1st cutting bar 10 of this invention is shown in FIG.
The first cutting bar 10 is mounted on the cutting bar mounting instrument 200, and the position of the handle 12 for cutting and gripping the root canal, and the position of the fractured portion of the root canal treatment instrument remaining in the root canal. The guide part 16 to guide is provided.

  The handle 12 is a metal rod having a diameter of about 0.10 mm to 1.00 mm and a length of about 30.00 mm or less. The handle 12 may be tapered from the proximal end to the distal end of the metal rod as shown in FIG. 2, or taper from the proximal end to the distal end of the metal rod. It may be in the shape. In this case, the outer diameter of the metal bar at the distal end of the metal bar is preferably 0.50 mm or more and 0.70 mm or less. It is preferable that the material of the handle 12 includes a metal having durability and corrosivity. Examples of such a metal include stainless steel, nickel titanium, cobalt chromium, and other alloys, and stainless steel is particularly preferable.

  The blade 14 is provided on the side of the proximal portion of the guide portion at the distal end of the handle 12, and is oriented in a direction perpendicular to the metal bar. The material of the blade 14 is not particularly limited, but is preferably stainless steel, nickel titanium, cobalt chrome, other alloys, plastics, or the like. The number of blades provided on the handle 12 is not particularly limited, but is preferably plural, and particularly preferably three or four. When there are a plurality of blades, the interval between them is not particularly limited, but it is preferable to provide them at regular intervals. The shape of the blade is not particularly limited, but is preferably a round blade.

  The guide portion 16 is provided at the most distal end of the handle 12. The material of the guide portion 16 may be stainless steel, nickel titanium, cobalt chrome, other alloys, or the like, but may be an elastic material such as plastic. As shown in the design diagrams of FIGS. 2 and 5, the length of the guide portion 16 is preferably 0.35 mm or more and 1.75 mm, particularly preferably 0.50 mm. The guide portion 16 is preferably tapered from the proximal end toward the distal end. In this case, the width of the distal end of the guide portion 16 is preferably 0.10 mm or more and 0.50 mm or less.

  Such a first cutting bar 10 according to the present invention has a guide portion, so that even if the root canal is curved, breakage of a root canal treatment instrument such as a reamer or a file left in the root canal. The root canal wall can be cut to a depth that reaches the fold.

(Ii) Second Cutting Bar FIG. 3 shows a schematic configuration of the second cutting bar 20 of the present invention.
The second cutting bar 20 is attached to the cutting bar mounting device 200 and has a handle 22 for grasping, and the crown side of the root canal wall and / or the fractured portion of the root canal treatment device left on the root canal. A cutting blade 24 and a guide portion 26 for guiding the position of the fractured portion of the root canal treatment instrument are provided.

  The handle 22 is a metal rod having a diameter of about 0.10 mm to 1.00 mm and a length of about 30.00 mm or less. This metal bar is illustrated in FIG. 3 and the design drawings of FIGS. 6 and 7. The handle 22 may be tapered from the proximal end to the distal end of the metal rod as shown in FIG. 3, or may be tapered from the proximal end to the distal end of the metal rod. It may be. In this case, the outer diameter of the metal bar at the distal end of the metal bar is preferably 0.50 mm or more and 0.70 mm or less. It is preferable that the material of the handle 22 includes a metal having durability and corrosivity. Such a metal is not particularly limited, and examples thereof include stainless steel, nickel titanium, cobalt chromium, and other alloys, and stainless steel is particularly preferable.

  The blade 24 is provided at the distal end of the handle 22 at the proximal portion of the second guide portion, and faces the tip direction of the metal rod. The material is not particularly limited, but stainless steel, nickel titanium, cobalt chrome, etc. Preferably, it is an alloy, plastic, or the like. The number of blades provided on the handle 22 is not particularly limited, but is preferably a plurality, more preferably 2 to 10, and particularly preferably 2. When there are a plurality of blades, the interval between them is not particularly limited, but it is preferable to provide them at regular intervals. The shape of the blade is not particularly limited, but is preferably a round blade. The outer diameter of the portion where the teeth are provided is preferably 0.50 mm or more and 0.70 mm or less, and particularly preferably 0.70 mm.

  The guide portion 26 is provided at the most distal end of the handle 22. The material of the guide portion 26 may be stainless steel, nickel titanium, cobalt chrome, other alloys, or the like, but may be an elastic material such as plastic. As shown in FIGS. 3, 6, and 7, the length of the guide portion 26 may be shorter than the length of the first guide portion 16, for example, 0.10 mm or more and 0.30 mm or less. It is preferable. Moreover, it is preferable that the width | variety from the outer wall of the guide part 26 to the outer wall of the distal end of a metal rod is 0.25 mm or more. Moreover, it is preferable that the guide part 26 is tapered from the proximal end toward the distal end. In this case, the width of the distal end of the guide part 26 is preferably 0.10 mm or more and 0.50 mm or less.

  The second cutting bar 20 according to the present invention can cut the root canal wall to a depth that reaches the broken piece of the root canal treatment instrument such as a reamer or a file left in the root canal. Further, by having the guide portion 26 having an appropriate length, even if the root canal is curved, it can reach the vicinity of the broken piece without cutting the root canal wall.

(Iii) Third Cutting Bar FIG. 4 shows a schematic configuration of the third cutting bar 30 of the present invention.
The third cutting bar 30 is mounted on the cutting bar mounting device 200 and has a handle 32 for gripping, and a root canal wall and / or a broken piece of a root canal treatment device such as a reamer or file left on the root canal. And a blade 34 that cuts the crown side.

  The handle 32 is a metal rod having a diameter of about 0.10 mm to 1.00 mm and a length of about 30.00 mm or less. The handle 32 may be tapered from the proximal end to the distal end of the metal bar as shown in FIG. 4, or tapered from the proximal end to the distal end of the metal bar. It may be. As shown in FIG. 4 and the design drawings of FIGS. 8 to 10, the metal rod has a cylindrical shape at its distal end. The outer diameter of the tube provided at the distal end of such a metal rod may be a size that does not cut the root canal wall, and is preferably 0.50 mm or more and 0.70 mm or less, particularly 0.70 mm. It is preferable that Further, the inner diameter of the tube may be a size that can shape the shape of the crown side of the fractured piece of the root canal treatment instrument such as a reamer or a file left in the root canal, and is 0.33 mm or more and 0 It is preferably 50 mm or less, and particularly preferably 0.50 mm. Further, the length of the tube can be appropriately changed in accordance with the deformation and curvature of the root canal, but is preferably 0.40 mm or more and 1.20 mm or less. The material of the handle 32 having a cylindrical shape preferably includes a metal having durability and corrosivity. Examples of such a metal include stainless steel, nickel titanium, cobalt chromium, and other alloys, and stainless steel is particularly preferable.

  The blade 34 is provided at the edge of the tip of the cylinder of the handle 32 and faces the tip of the metal bar. The material of the blade 34 is not particularly limited, but is preferably stainless steel, nickel titanium, cobalt chrome, other alloys, plastics, or the like. The number of blades provided on the handle 32 is not particularly limited, but is preferably a plurality, more preferably 2 to 10, and particularly preferably 8. When there are a plurality of blades, the interval between them is not particularly limited, but it is preferable to provide them at regular intervals. The shape of the blade is not particularly limited, but is preferably a round blade.

  Such a third cutting bar 30 according to the present invention is a root canal wall that has been shaved to the vicinity of a broken piece of a root canal treatment instrument such as a reamer or a file left in the root canal by the second cutting bar 20. And / or shaving the crown side of the broken piece, or shaving the crown side of the broken piece of a root canal treatment device such as a reamer or a file left in a deformed or curved root canal. Finally, the shape of the broken piece can be made the same shape as the lumen of the tube at the tip.

(Iv) Other Cutting Bars The cutting bar set of the present invention may include similar cutting bars in addition to these three cutting bars.
For example, a plurality of cutting bars having the same shape as the second cutting bar 20 as a whole and having different guide lengths may be included. In this case, the length of the guide portion may be shorter than the length of the first guide portion 16, and for example, it is preferable to align cutting bars such as 0.10 mm, 0.20 mm, and 0.30 mm. Further, a plurality of cutting bars having the same shape as that of the third cutting bar 30 as a whole and having different lengths of the cylinders at the tip end portions may be included. In this case, it is preferable to align cutting bars such as 0.60 mm, 0.80 mm, and 1.20 mm as the length of the cylinder.

(1-2) Cutting bar mounting device 200
The cutting bar mounting tool 200 is a tool for mounting and operating a cutting bar. For example, a dental punch, a dental drill, a dental puncture device and the like can be mentioned, but as long as the cutting bar of the present invention can be operated, its configuration, shape, material and the like are not particularly limited, and are commercially available. It may be.

(2) Broken piece removal instrument 400
Although the broken piece removal instrument used by this invention is not specifically limited, As an example, the structure of the broken piece removal instrument 400 is shown to Fig.11 (a), (b).

  The broken piece removing device 400 includes a handle 410 held by the operator, and a wire 420 for removing broken pieces of the root canal treatment device left in the root canal out of the root canal.

  As shown in FIG. 11A, the shape of the handle 410 is not particularly limited as long as it is a size that is easy for an operator to hold and operate. It is preferable that the material of the handle 410 includes a metal having durability and corrosivity. Examples of such a metal include stainless steel, nickel titanium, cobalt chromium, and other alloys, and stainless steel is particularly preferable. Inside the proximal end of the handle 410, a wire fixing portion 422 for fixing the terminal portion of the wire 420 is provided.

  The wire 420 is a high-strength wire having a diameter of 0.03 mm to 0.30 mm, preferably 0.06 mm to 0.12 mm. The material of the wire 420 is not specifically limited, For example, stainless steel etc. are mentioned. The wire 420 may be plated with nickel or the like. Such a wire 420 is provided at the distal end of the handle 410. As the shape of the wire 420, it is preferable that the wire 420 has a shape that allows a broken piece of the root canal treatment instrument remaining in the root canal to be hooked. For example, as shown in FIG. It is preferable to apply in a loop shape. The wire 420 having such a shape is fixed to the distal end of the handle 410, and the terminal portion of the wire 420 is fixed to the wire fixing portion 422. Note that the configuration, shape, material, and the like of the wire fixing portion 422 are not particularly limited as long as the wire 420 can be fixed.

=== How to use the broken piece removal set ===
The broken piece removal set according to the present invention includes a broken piece cutting device 300 and a broken piece removing instrument 400, and a root canal treatment instrument left in the root canal 600, which is generated during tooth root canal treatment. This is used to cut the root canal when removing the broken pieces. In addition, when removing the broken piece of the instrument for root canal treatment, you may carry out, observing a root canal part with a dental microscope. Hereinafter, the usage method of a broken piece removal set is described.

  First, in the broken piece removal set of the present invention, the first cutting bar 10 shown in FIG. Then, the root canal is expanded while cutting the inner wall of the root canal with a laterally attached blade (see FIG. 12). At this time, since the guide portion 16 is present at the tip, the cutting bar 10 is prevented from being diverted sideways and cutting the root canal in a direction that breaks through the inner wall of the root canal. When the guide part 16 reaches the broken piece such as a reamer or a file left in the root canal, the first cutting bar 10 cannot advance first, so that the cutting of the root canal wall is stopped. The shaved root canal wall is preferably removed outside the root canal using an instrument such as suction. By this step, the width of the root canal can be uniformly expanded as much as necessary without excessively cutting the root canal wall to near the broken piece.

  Next, in the broken piece removal set of the present invention, the second cutting bar 20 shown in FIG. 3 is mounted on the cutting bar mounting device 200, and the second cutting bar 20 is attached to the root canal 600 from the blade 24. Insert (see FIG. 12). As the second cutting bar 20 used here, one having a guide portion 26 of an appropriate length is selected according to the state of the root canal that is curved or deformed (see, for example, FIG. 6 or FIG. 7). .

  Similarly to the first cutting bar 10, when the second cutting bar 20 is inserted, if the guide portion 26 is slowly inserted along the inner surface of the root canal 600, the second cutting bar 20 is not damaged. The cutting bar 20 can be inserted into the root canal 600. When the guide portion 26 reaches a portion where the cutting of the first cutting bar 10 has stopped, the second cutting bar 20 is operated using a power source or the like provided in the cutting bar mounting tool 200. Since the second cutting bar 20 has a guide portion 26 shorter than the first cutting bar 10 and has a blade 24 facing in the forward direction, the guide portion 26 fits into a root canal that has not been cut, The first cutting bar 10 cuts the root canal wall that could not be expanded, and further advances while expanding the root canal. And when the guide part 26 reaches | attains broken pieces, such as a reamer and a file left in the root canal, since the 2nd cutting bar 20 cannot advance previously, it stops cutting a root canal wall again. During this operation, the broken piece may be scraped off, but it is preferable to remove the shaved root canal wall and the broken piece powder to the outside of the root canal using a device such as suction.

  In this process, it is preferable to use a plurality of second cutting bars 20 having different lengths of the guide portion 26. In that case, it is preferable to shorten the length of the guide part 26 gradually. For example, first, the root canal wall is shaved with a cutting bar having a long guide portion 26 (see FIG. 6; for example, 0.3 mm), and then a cutting bar having a short guide portion 26 (see FIG. 7). For example, 0.1 mm), the orientation of the second cutting bar 20 by the guide portion is stabilized, so that the root canal wall can be more stably shaved without removing excess portions. Can do. Here, the second cutting bar is not limited to two types, and three or more types having different lengths of the guide portion 26 may be used. Further, the second cutting bar 20 to be used last preferably has a short guide portion 26, and a second cutting bar 20 without the guide portion 26 may be used. As a result, at the stage where the cutting process by the second cutting bar 20 is finished, the root canal wall is not cut excessively or unnecessarily, to the very vicinity of the broken piece, or until the broken piece is exposed. The root canal wall can be expanded.

  Finally, the third cutting bar 30 shown in FIG. 4 is used in the broken piece removing set of the present invention so that the broken piece 500 can be removed using the broken piece removing instrument 400. Then, the crown side of the broken piece is cut into a cylindrical shape and protruded from the root.

  First, the third cutting bar 30 shown in FIG. 4 is mounted on the cutting bar mounting tool 200, and the third cutting bar 30 is inserted into the root canal 600 from the blade 34 (see FIG. 12). 34 is applied to an uncut root canal wall on or around the crown side of the broken piece. The 3rd cutting bar 30 used here uses the thing of an appropriate shape in consideration of the state of the broken piece in a root canal, etc. (for example, refer to Drawing 8-Drawing 10).

  Next, the third cutting bar 30 is operated using a power source or the like provided in the cutting bar mounting device 200, and the root canal wall around or around the crown side of the fractured piece is cut. If the root canal is greatly deformed or curved, the blade tip of the blade 34 may be appropriately tilted to cut the broken piece. When the root canal wall on or around the crown of the broken piece is cut, the broken piece enters the inside of the cylinder at the tip of the third cutting bar 30 and finally the broken piece becomes a cylinder. When it gets in, it can no longer cut. Therefore, the shape of the broken piece on the crown side can be made the same shape as the tip tube. In the same manner as described above, the broken pieces and root canal wall powder shaved in this step are preferably removed outside the root canal using an instrument such as suction.

  In this process, it is preferable to use a plurality of third cutting bars 30 having different cylinder lengths so that the cylinder length gradually increases. For example, a broken piece or a root canal wall is first cut with a cutting bar having a short tube length (see FIG. 8; for example, 0.6 mm), and then a cutting bar having a slightly long tube length (see FIG. 9). For example, 0.8 mm), and then by using the cutting bar with the longest tube length (see FIG. 10; for example, 1.2 mm) The shape on the crown side of the broken piece can be made exactly the same as that of the cylinder without being scraped unnecessarily or unnecessarily. Here, the third cutting bar is not limited to three types, and two types or three or more types having different cylinder lengths may be used.

  In addition, it is preferable that the cutting bar 100 is made brittle by narrowing the width of the handle on the proximal side so that the tip is not broken and left behind at the tip of the root canal. As a result, when an excessive force is applied when cutting the root canal or the fractured piece, the handle of the cutting bar 100 is bent first from the tip of the cutting bar 100, and the broken part can be easily recovered. Become. In the unlikely event that it breaks, a new cutting bar 100 may be mounted on the cutting bar mounting tool 200 as appropriate.

  Finally, the broken piece which exists in a root canal is removed out of a root canal using the broken piece removal instrument 400 shown in FIG.

  First, the wire 420 shown in FIGS. 11A and 11B is hooked on a broken piece such as a reamer or a file remaining in the root canal. When the wire 420 cannot be hooked on the broken piece 500 such as a reamer or a file, the length of the wire 420 is reduced by increasing or decreasing the length of the wire fixed by the wire fixing portion 422. What is necessary is just to adjust suitably. The broken piece 500 hooked by the wire 420 in this manner is pulled out so as not to fall out of the wire 420 and is taken out of the root canal (see FIGS. 13A and 13B).

  As described above, by using the method of the present invention, broken pieces such as reamers and files can be easily removed outside the root canal without excessively or unnecessarily shaving the root canal wall.

In one Example of this invention, it is the figure which showed the structure of the broken piece cutting device. FIG. 5 is a diagram illustrating a configuration of a first cutting bar in an embodiment of the present invention. FIG. 6 is a diagram illustrating a configuration of a second cutting bar in an embodiment of the present invention. In one Example of this invention, it is the figure which showed the structure of the 3rd cutting bar. FIG. 4 is a diagram showing a design drawing of a first cutting bar in an embodiment of the present invention. FIG. 5 is a diagram showing a design drawing of a second cutting bar in an embodiment of the present invention. FIG. 5 is a diagram showing a design drawing of a second cutting bar in an embodiment of the present invention. In the Example of this invention, it is the figure which showed the design drawing of the 3rd cutting bar. In the Example of this invention, it is the figure which showed the design drawing of the 3rd cutting bar. In the Example of this invention, it is the figure which showed the design drawing of the 3rd cutting bar. In one Example of this invention, it is the figure which showed the structure of the broken piece removal instrument. In one Example of this invention, it is the figure which showed the broken piece left in the root canal. (A) In one Example of this invention, it is the figure which showed the broken piece left in the root canal. (B) In one Example of this invention, it is the figure which showed the procedure which removes the broken piece left in the root canal using the broken piece removal instrument.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 1st cutting bar 12 handle 14 blades 16 guide part 20 2nd cutting bar 22 handle 24 blades 26 guide part 30 3rd cutting bar 32 handle 34 blades 100 cutting bar 200 cutting bar installation tool 300 broken piece cutting Device 400 Broken piece removing tool 410 Handle 420 Wire 422 Wire fixing part 500 Broken piece 600 Root canal

Claims (10)

A cutting bar set for removing broken pieces of the root canal treatment instrument left in the root,
A first cutting bar for cutting the root canal wall;
A second cutting bar for scraping the crown side of the root canal wall and / or the fracture piece of the root canal treatment device left on the root canal;
A third cutting bar that cuts the crown side of the root canal wall and / or the fractured portion of the root canal treatment instrument left on the root canal;
With
The first cutting bar is
A metal rod,
A first guide portion protruding from a distal end of the metal rod;
A first blade provided on a side surface of a proximal portion of the first guide portion and oriented vertically with respect to the metal rod;
With
The second cutting bar is
A metal rod,
A second guide portion protruding from a distal end of the metal rod;
A second blade provided at a proximal portion of the second guide portion and facing a tip direction of the metal rod;
With
The third cutting bar is
A metal rod,
A tube provided at the distal end of the metal rod; a third blade provided at an edge of the tip of the tube and facing the tip direction of the metal rod;
Providing
Cutting bar set featuring   The length of the said 1st guide part is 0.35 mm or more and 1.75 mm or less, The cutting bar set of Claim 1 characterized by the above-mentioned.   The cutting bar set according to claim 1 or 2, wherein a width of a distal end of the first guide portion is 0.10 mm or more and 0.50 mm or less.   The length of the said 2nd guide part is shorter than the length of the said 1st guide part, The cutting bar set in any one of Claims 1-3 characterized by the above-mentioned.   The cutting bar set according to any one of claims 1 to 4, wherein an outer diameter of the metal bar at a distal end of the metal bar is not less than 0.50 mm and not more than 0.70 mm.   The cutting bar set according to any one of claims 1 to 5, wherein a width from an outer wall of the second guide portion to an outer wall of the second blade is 0.25 mm or more.   The cutting bar set according to any one of claims 1 to 6, wherein an outer diameter of the cylinder is not less than 0.50 mm and not more than 0.70 mm.   The cutting bar set according to any one of claims 1 to 7, wherein an inner diameter of the cylinder is 0.33 mm or more and 0.50 mm or less.   The length of the said cylinder is 0.40 mm or more and 1.20 mm or less, The cutting bar set in any one of Claims 1-8 characterized by the above-mentioned.   The cutting bar according to any one of claims 1 to 9, further comprising a hooking device having a loop-shaped wire for removing a broken piece cut by the third cutting bar outside the root canal. set.

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