WO2024186111A1

WO2024186111A1 - Endo file for dental nerve treatment

Info

Publication number: WO2024186111A1
Application number: PCT/KR2024/002844
Authority: WO
Inventors: 김형우
Original assignee: 주식회사 덴플렉스
Priority date: 2023-03-06
Filing date: 2024-03-06
Publication date: 2024-09-12
Also published as: KR20240136037A

Abstract

The present invention relates to an endo file for dental nerve treatment, the endo file including: a cutting blade part formed at one end thereof; and a handpiece mounting part which is provided at the other end thereof and is coupled to a handpiece, wherein the cutting blade part is configured such that, in a view on the cross-sectional surface of the cutting blade part, a virtual circle, the center point of which corresponds to the rotation center axis of the endo file, is in contact with only two points of the cutting blade part so that a predetermined section of the cutting blade part includes the cross-sectional surface of the cutting blade part therein.

Description

Endopile for dental nerve treatment

The present invention relates to an endofile for dental nerve treatment, and more particularly, to an endofile structure which is newly designed to secure additional space between the cutting edge of the endofile and the inner wall of a root canal, thereby enabling tissues removed by the cutting edge during a root canal procedure to be smoothly discharged to the outside, reducing the phenomenon of the cutting edge being broken during the procedure, and enabling the easy removal of the broken cutting edge even when the cutting edge is broken during the procedure and becomes embedded in the inner wall of a root canal.

In general, an endodontic file is a medical tool used to remove the dental nerve of a tooth. It is inserted deep into the root canal where a lesion has occurred to remove the nerve and/or diseased tissue. Since it must bend according to the shape of the tooth, it is made of an elastic material.

Endopiles of this type are widely used in dental clinics all over the world, and are mounted on a handpiece that rotates by the power of an air or electric motor.

The endofile detachably attached to the handpiece rotates the cutting edge formed at one end of the endofile when the handpiece is in operation, and the rotating cutting edge enables the removal of nerves, blood vessels, and tissues of the diseased tooth. During such root canal treatment, the cutting edge of the endofile is repeatedly inserted and pulled into the root canal.

As described in the applicant's registered patent No. 10-2130201, conventional endopiles are mostly configured so that, when viewed in cross-section at any point of the cutting edge, when an imaginary circle is drawn with the rotational center axis of the endopile as the center point, including the cross-section of the cutting edge inside, any imaginary circle comes into contact with the cutting edge at least at three points. For example, conventional endopiles have a cross-section of the cutting edge formed as an equilateral triangle, square, or rectangle (see FIGS. 4(a) to 4(c)), and are configured so as to come into contact with an imaginary circle with the rotational center axis or longitudinal center axis of the endopile as the center point and including the cross-section of the cutting edge inside at mostly three or four points. In this case, the cutting edge forms an angular cutting edge that can actually perform a cutting function at three or four points that come into contact with the imaginary circle.

However, such conventional endofiles have a problem in that the tissues removed by the cutting edge are not smoothly discharged to the outside during a root canal treatment procedure due to a narrow space between the cutting edge and the inner wall of the root canal. In addition, when the cutting edge of the endofile rotates while three or more points of the cutting edge are in contact with the curved root canal, three or more points of contact surface are generated with the inner wall of the root canal, causing the endofile to bend to the same degree as the curved root canal shape. As a result, excessive compression and tension stress are repeatedly generated in a certain part of the endofile at the point of bending during rotation, which causes the cutting edge to break during the procedure. In particular, as illustrated in FIG. 3, when performing a root canal treatment while the endo file is bent and inserted into a curved root canal, the tip of the cutting edge may break due to stress concentration, etc., and become embedded in the inner wall of the root canal. In this case, since the tip is in strong contact with the inner wall of the root canal at more than three points, it is not easy to remove the broken cutting edge. In order to remove the tip portion that is broken and embedded in the inner wall of the root canal, a space is required in which an instrument can be positioned between the broken file portion and the inner wall of the root canal. However, in the existing structure that makes contact with the inner wall of the root canal at more than three points, there was a serious problem in which removal itself was impossible.

In another conventional endo file, there are cases where the cutting edge is formed such that it contacts an imaginary circle containing the cross section of the cutting edge inside the endo file with the rotational center axis as the center point and only at two points (see Fig. 4(d)). That is, in this case, the line connecting the center point of the imaginary circle and the contact points of the two points forms 180 degrees that bisects the imaginary circle. In an endo file with this structure, the two points where the cutting edge is formed are located at symmetrical points facing each other with the rotational center axis in between. Therefore, when the cutting edge rotates inside the circular root canal wall, if one of the two points contacting the imaginary circle receives resistance or both points receive excessive rotational resistance at the same time, since the cutting edge contacting the imaginary circle is located at a symmetrical point with the rotational center axis as the center point, the material deforms and there is no space for buffering, and as a result, the problem of the endo file tip breaking still exists, as in other conventional endo files that contact the imaginary circle at three points, due to excessive stress accumulating in the cutting edge.

The purpose of the present invention is to form a certain section of the cutting edge so that, when an imaginary circle is drawn with the rotational center axis of an endo file as its center point so as to include the cross-section of the cutting edge therein when viewed in the cross-section of the cutting edge, the imaginary circle and the cutting edge are in contact at only two points, and the two angles created by connecting the two points in contact with the imaginary circle and the center point of the imaginary circle are not the same, thereby additionally securing sufficient asymmetrical free space between the cutting edge and the inner wall of the root canal when performing a root canal treatment using an endo file, compared to a conventional endo file.

In addition, the purpose of the present invention is to enable tissues removed by the cutting edge of an endo file during a root canal treatment to be discharged more smoothly through the additionally secured asymmetrical free space. That is, the free space formed between the cutting edge portion that does not contact the imaginary circle and the inner root wall serves as a smooth discharge passage for tissues removed by the cutting edge during a root canal treatment.

In addition, the purpose of the present invention is to provide a method for reducing stress accumulation or concentration on the cutting edge by using sufficient asymmetrical free space when a rotational resistance exceeding a certain limit is applied to the cutting edge at a certain point during a root canal treatment in which an endofile is rotated to remove contaminated tissues in the root canal, by deforming the endofile and alleviating the applied shock using the sufficient asymmetrical free space. In particular, when performing a treatment in a curved root canal with an endofile inserted in a curved state, when looking at the cross-section of the cutting edge of the endofile inserted in a curved state into the curved root canal, only two points of the cutting edge that come into contact with an imaginary circle during rotation come into contact with the inner wall of the root canal, and the remaining portions that do not come into contact with the imaginary circle form a free space between them and the inner wall of the root canal, so that when a rotational resistance exceeding a certain limit is applied during the root canal treatment in a curved state, the cutting edge can move to some extent toward the free space. Therefore, during a root canal treatment in which an endo file rotates to remove tissues in the root canal, when a rotational resistance exceeding a certain limit is applied to a certain point, the shock can be alleviated by deforming by the amount of the above-mentioned free space, and as a result, the stress received is reduced compared to a conventional endo file, so that relatively less stress is generated on the cutting edge. This phenomenon is equally applicable to root canal treatment in a straight section, not a curved root canal.

In addition, the purpose of the present invention is to enable a new endo file to be filed into a free space formed in a portion that does not contact an imaginary circle when an endo file is broken and embedded in the inner wall of a root canal due to continuous stress, and in this case, when the tip of the new endo file rotates while finding a sufficiently asymmetrical free space between the broken file and the inner wall of the root canal, the phenomenon of causing the broken and embedded endo file to rotate in the opposite direction occurs. That is, when the tip of the new endo file digs into the free space and enters, it rotates the embedded endo file in the opposite direction, thereby making it easy to pull out and remove the broken and embedded endo file.

In addition, the purpose of the present invention is to form two angles at unequal positions when two points of a cutting edge in contact with an imaginary circle are connected to the center point of the circle, so that even when an endo file breaks due to continuous stress and is embedded in a root canal, two points exist within an angle less than 180 degrees with respect to the center point of the imaginary circle, and an asymmetrical free space exists at the opposite position. Accordingly, the cutting edge is embedded in the inner wall of the root canal relatively less strongly only at the two points of the cutting edge, and as a result, the broken and embedded endo file can be removed more easily.

In order to achieve the above-described purpose, an endofile for dental nerve treatment according to an embodiment of the present invention comprises a cutting blade portion having a cutting edge formed in a spiral shape along a longitudinal direction at one end, and a handpiece mounting portion coupled to a handpiece at the other end, wherein when a certain section of the cutting blade portion is viewed in cross-section of the cutting blade portion, when an imaginary circle centered on the rotational center axis of the endofile is drawn such that the cross-section of the cutting blade portion is included inside, the imaginary circle comes into contact only at two points of the cutting blade portion, and two angles formed by connecting the center point of the imaginary circle and the two points are not the same.

Preferably, the smaller angle (Q) of the two angles formed by connecting the center point of the virtual circle and the two points is less than 170 degrees.

More preferably, the angle (G) of the cutting edge portion contacting the virtual circle at two points is formed between 30 and 80 degrees.

According to the present invention, the following effects are achieved.

First, when performing a root canal treatment using an endofile, an additional space can be secured between the cutting edge and the inner wall of the root canal compared to a conventional endofile, so that the tissues removed by the cutting edge of the endofile during the root canal treatment can be discharged more smoothly through the additional space secured. In other words, the space formed between the cutting edge portion that does not come into contact with the imaginary circle and the inner wall of the root canal serves as a smooth discharge passage for the tissues removed by the cutting edge during the root canal treatment.

Second, when looking at the cross-section of the cutting edge of the endo file introduced in a curved root canal in a curved state, the cutting edge contacts the inner wall of the root canal only at two points where it contacts an imaginary circle, and the two angles formed by connecting the two points and the center point of the imaginary circle are not identical, so that the portion of the larger angle among the two angles forms sufficient free space without a point of contact with the imaginary circle, so that the cutting edge can move to some extent toward the free space during the root canal treatment in a curved state, and as a result, when the rotational resistance force exceeding the material strength of the endo file material is generated during the root canal treatment and the endo file must be deformed to cushion this impact, it can be additionally deformed by the amount of the free space, thereby having the effect of generating relatively less stress on the cutting edge than the conventional endo file. Therefore, even when the endo file is introduced in a curved root canal in a curved state, the occurrence of stress or stress concentration at the cutting edge can be reduced, thereby reducing the breakage of the cutting edge of the endo file.

Third, even if an endo file is fractured due to continuous stress and is embedded in the inner wall of a root canal, a new endo file can be filed through sufficient free space formed in the area having the larger angle among the two angles formed when two points in contact with an imaginary circle and the center point of the imaginary circle are connected, and in this case, the tip of the new endo file digs into the sufficient free space and rotates the embedded endo file in the opposite direction, thereby having the effect of easily pulling out and removing the fractured and embedded endo file.

Fourth, even if the endo file breaks and becomes lodged in the root canal due to continuous stress, the two points are relatively less strongly lodged in the inner wall of the root canal, which results in the effect of making it easier to remove the broken and lodged endo file.

FIG. 1 is a perspective view illustrating the entire endo file structure together with the cross-sectional shape of the cutting edge portion according to an embodiment of the present invention.

FIG. 2 illustrates examples of various shapes of cross-sections of a cutting edge portion that can be formed according to another embodiment of the present invention.

Figure 3 is a photographic image showing an example of a procedure in which the cutting part of an endofile is inserted into a curved root canal during a root canal treatment using an endofile.

Figure 4 is a drawing showing a cross-section of a cutting edge applied to a conventional endo file.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the drawings.

Referring to FIG. 1, an endo file (100) for dental nerve treatment according to one embodiment of the present invention is configured to include a handpiece mounting portion (10) coupled to a handpiece, a stress dissipation portion (20) formed of a plurality of coil spring ribs to secure bendability, and a cutting blade portion (30) inserted into a patient's root canal to cut and remove diseased tissue and nerves.

As shown in Fig. 1, a cutting edge portion (30) is provided at one end of the endo file, a handpiece mounting portion (10) is provided at the other end of the endo file, and a stress dissipation portion (20) is formed between the handpiece mounting portion (10) and the cutting edge portion (30).

As shown in the enlarged cross-sectional view A-A of FIG. 1, the cutting edge portion (30) of the present invention is configured such that when a virtual circle is drawn with the rotational center axis (X) of the endo file as the center point so as to include the cross-section of the cutting edge portion (30) inside when viewed in cross-section of the cutting edge portion (30), the virtual circle comes into contact only at two points of the cutting edge portion, and the two angles formed by connecting the center point of the virtual circle and the two points are not the same.

Referring to FIG. 1, the cutting edge portion (30) is configured to include four cutting edges (32a, 32b, 32c, 32d) (i.e., portions corresponding to each vertex of the cross-section when viewed in the cross-section of the cutting edge portion). The two lower cutting edges (32a, 32b) contact the virtual circle at two points, while the two upper cutting edges (32c, 32d) do not contact the virtual circle, thereby allowing additional space to be secured between the cutting edge portion and the inner wall of the root canal during root canal treatment compared to a conventional endo file.

In this way, the free space formed between the cutting edge that does not come into contact with the virtual circle and the inner root wall serves as a smooth discharge passage for tissues removed by the cutting edge during a root canal treatment. In addition, thanks to the additional asymmetrical free space, the cutting edge can move to some extent toward the free space, especially during a root canal treatment when the endo file is bent, and as a result, when the endo file must be bent during a root canal treatment, relatively less stress is generated on the cutting edge than in a conventional endo file by the amount of the free space.

Preferably, the angle (G) of the cutting edges (32a, 32b) at two points contacting the virtual circle is formed within the range of 30 to 80 degrees.

More preferably, the smaller angle (Q) of the two angles formed by connecting the center point (X) of the virtual circle and the two points (32a, 32b) of the cutting edge is formed within 170 degrees.

Preferably, the cutting edges are continuously formed to form a spiral along the longitudinal direction of the cutting edge portion, as illustrated in Fig. 1. In this way, especially since the cutting edges have a structure formed in a spiral along the longitudinal direction of the cutting edge portion, when the cutting edges positioned at a specific point of the cutting edge rotate, the cutting edges that come into contact with an imaginary circle at two points rotate along the entire circumference, so that even if the cutting edges come into contact only at two points, a sufficient cutting function can be exhibited.

In addition, since the cutting edges are formed in a spiral shape along the longitudinal direction of the cutting edge portion, when the endo file is fractured due to continuous stress and becomes embedded in the inner wall of the root canal, the tip of a new endo file digs into the free space and rotates while engaging with the spiral cutting edge of the embedded endo file, thereby rotating the embedded endo file in the opposite direction, allowing the embedded endo file to be easily pulled out and removed.

FIG. 2 illustrates examples of various shapes of cross-sections of a cutting edge portion that can be configured according to another embodiment of the present invention. However, these examples of cross-sections are merely exemplary for the purpose of helping understanding, and it is obvious that the present invention can be implemented as additional examples of various shapes.

Figure 2(a) illustrates a configuration similar to Figure 1 in which the two lower cutting edges contact the imaginary circle at two points, and the two upper cutting edges do not contact the imaginary circle.

Fig. 2(b) also illustrates, similarly to Figs. 1 and 2(a), that the two lower cutting edges are configured to contact the imaginary circle at two points, and that the two upper cutting edges do not contact the imaginary circle. However, in this case, only the upper right cutting edge has a structure that protrudes further toward the imaginary circle.

Figure 2(c) illustrates that the lower two cutting edges are configured to contact the imaginary circle at two points, and the upper three cutting edges do not contact the imaginary circle.

Figure 2(d) illustrates that the lower two cutting edges are configured to contact the imaginary circle at two points, and the upper one cutting edge does not contact the imaginary circle.

Although the present invention has been described in detail with reference to the drawings and specific embodiments thereof, the present invention is not limited to such specific structures. Those skilled in the art will be able to modify or change the present invention in various ways without departing from the technical spirit and scope of the present invention as set forth in the following claims. However, it should be made clear in advance that such simple design material modifications or modified structures are all clearly within the scope of the present invention.

Claims

In the case of endo files for dental nerve treatment,

An endofile for dental nerve treatment, comprising: a cutting blade portion having a cutting edge formed in a spiral shape along a longitudinal direction at one end; a handpiece mounting portion coupled to a handpiece at the other end; and wherein, when a certain section of the cutting blade portion is viewed in cross-section from the cross-section of the cutting blade portion, when an imaginary circle centered on the rotational center axis of the endofile is drawn such that the cross-section of the cutting blade portion is included therein, the imaginary circle contacts only two points of the cutting blade portion, and two angles formed by connecting the center point of the imaginary circle and the two points are not the same.
An endo file for dental nerve treatment, characterized in that the smaller angle (Q) of the two angles formed by connecting the center point of the virtual circle and the two points in the first clause is less than 170 degrees.
An endo file for dental nerve treatment, characterized in that in the second paragraph, the angle (G) of the cutting edge part contacting the virtual circle at two points is formed between 30 and 80 degrees.