Interdental cleaning tools

Abstract

To provide interdental cleaning tools that offer excellent cleanability and durability. [Solution] An interdental cleaning tool having a main body and a soft part, the soft part having a soft shaft part and a brush part, the soft shaft part having a peripheral wall, the main body part having a base part and a core part, the core part extending into the peripheral wall and in close contact with the inner surface of the peripheral wall, the brush part having a predetermined number of rows of brush protrusions, the rows of brush protrusions consisting of a plurality of brush protrusions, the brush protrusions protruding from the outer peripheral surface of the peripheral wall, wherein the radial thickness of the peripheral wall at the base end is less than or equal to the radial thickness of the peripheral wall at the tip, the soft part having a soft shaft connecting part, the soft shaft connecting part extending from the base end of the soft shaft part, the base part having a main body shaft part and a plate-like part, the main body shaft part being exposed on the surface from the base end of the soft shaft part and extending to the tip of the plate-like part, the predetermined number of rows of brush protrusions having predetermined rows of brush protrusions, the predetermined rows of brush protrusions protruding along the width direction of the plate.

Description

Technical Field

[0001] The present invention relates to an interdental cleaning tool.

Background Art

[0002] As an interdental cleaning tool having a main body part and a soft part, the soft part is made of an elastic material having a hardness lower than that of the main body part and has a soft shaft part and a brush part. The soft shaft part extends in the axial direction and has a peripheral wall. The main body part has a base part and a shaft core part. The base part extends from the proximal end of the soft shaft part toward the proximal end side in the axial direction. The shaft core part extends from the tip of the base part into the peripheral wall of the soft shaft part and adheres to the inner surface of the peripheral wall. The brush part has a predetermined number of rows of brush protrusions. The predetermined number of rows of brush protrusions are arranged in the circumferential direction when viewed in the axial direction. Each row of brush protrusions consists of a plurality of brush protrusions, and the brush protrusions protrude radially outward from the outer peripheral surface of the peripheral wall. This is known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] For an interdental cleaning tool as described above, cleaning performance that can easily clean the interdental spaces and durability that is not easily damaged are important.

[0005] An object of the present invention is to provide an interdental cleaning tool excellent in cleaning performance and durability.

Means for Solving the Problems

[0006] One aspect of the present invention is as follows.

[0007] [1] It has a main body part and a soft part, The soft part is made of an elastic material having a hardness lower than that of the main body, and has a soft shaft portion and a brush portion. The aforementioned soft shaft portion extends in the axial direction and has a circumferential wall. The main body portion has a base portion and an axial core portion, The base portion extends from the base end of the soft shaft portion toward the axial base end, The shaft core extends from the tip of the base into the circumferential wall of the soft shaft and is in close contact with the inner surface of the circumferential wall. The brush portion has a predetermined number of rows of brush protrusions, The predetermined number of brush protrusion rows are arranged in the circumferential direction when viewed in the axial direction. The aforementioned row of brush protrusions consists of multiple brush protrusions, The brush projection is an interdental cleaning tool that protrudes radially outward from the outer surface of the peripheral wall, The radial thickness of the peripheral wall at the base end of the peripheral wall is less than or equal to the radial thickness of the peripheral wall at the tip end of the peripheral wall. The aforementioned soft part has a soft shaft connecting part, The flexible shaft connecting portion extends from the base end of the flexible shaft portion toward the axial base end, The base portion has a main shaft portion and a plate-shaped portion. The main shaft portion extends from the base end of the soft shaft portion to the tip of the plate-like portion, exposed on the surface, towards the base end in the axial direction. The plate-like portion has a width and thickness perpendicular to the axial direction. The predetermined number of brush protrusion rows have a predetermined number of brush protrusion rows. An interdental cleaning tool wherein the predetermined row of brush protrusions protrudes from the outer circumferential surface of the soft shaft portion along the width direction when viewed in the axial direction.

[0008] [2] The interdental cleaning tool according to [1], wherein the main shaft portion extends from the base end of the soft shaft portion to the tip of the plate-shaped portion, exposed on the surface on the side in the plate width direction, toward the axial base end.

[0009] [3] The main body shaft portion is exposed on the surface on both sides in the plate width direction from the base end of the soft shaft portion and extends to the tip end of the plate-shaped portion on the base end side in the axial direction, and is the interdental cleaning tool according to [1] or [2].

[0010] [4] The peripheral wall has a row of holes consisting of three holes arranged along the axial direction. The first outer diameter, which is the outer diameter of the peripheral wall at the first position, which is the axial position where the center of the hole on the most tip end side of the hole row is located, is 0.6 mm or less, and the second outer diameter, which is the outer diameter of the peripheral wall at the second position, which is the axial position where the center of the hole on the most base end side of the hole row is located, is 1.1 mm or less. The hole is recessed from the outer peripheral surface of the peripheral wall to the outer peripheral surface of the shaft core portion. The bottom surface of the hole is curved so as to form only one convex portion that protrudes outward in the radial direction when viewed in the axial direction. The depth of the hole on the most base end side of the hole row is less than or equal to the depth of the hole on the most tip end side of the hole row, and is the interdental cleaning tool according to any one of [1] to [3].

Advantages of the Invention

[0011] According to the present invention, an interdental cleaning tool excellent in cleaning performance and durability can be provided.

Brief Description of the Drawings

[0012] [Figure 1] (a) is an external view of an interdental cleaning tool according to an embodiment of the present invention as viewed from the first radial direction, and (b) is an external view of the interdental cleaning tool shown in (a) as viewed from the second radial direction. [Figure 2] It is a cross-sectional view taken along line A-A of FIG. 1(a). [Figure 3] It is a cross-sectional view taken along line B-B of FIG. 1(a). [Figure 4] It is a cross-sectional view taken along line C-C of FIG. 1(a). [Figure 5] It is a cross-sectional view taken along line D-D of FIG. 1(a). [Figure 6] It is an explanatory diagram for explaining the state when the interdental cleaning tool shown in FIG. 1 is used. [Figure 7] It is a cross-sectional view showing the state when inserting the brush part into the gap between teeth shown in FIG. 6. [Figure 8] It is a cross-sectional view showing the state when starting to pull back the brush part from the state of FIG. 7. [Figure 9] It is a cross-sectional view showing the state when further pulling back the brush part from the state of FIG. 8.

Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be exemplified and described with reference to the drawings.

[0014] As shown in FIGS. 1 to 5, in one embodiment of the present invention, the interdental cleaning tool 1 has a main body part 2 and a soft part 3. The soft part 3 is made of an elastic material having a hardness lower than that of the main body part 2 and has a soft shaft part 3a and a brush part 3b. The soft shaft part 3a extends in the axial direction and has a peripheral wall 3a1. The main body part 2 has a base part 2a and a shaft core part 2b. The base part 2a extends from the proximal end of the soft shaft part 3a toward the axial proximal end side. The shaft core part 2b extends from the tip of the base part 2a into the peripheral wall 3a1 of the soft shaft part 3a and adheres to the inner surface of the peripheral wall 3a1.

[0015] The shaft core part 2b is in the shape of an elongated shaft extending around the central axis O. The direction along the central axis O is called the axial direction. The direction from the base part 2a toward the soft shaft part 3a along the axial direction is called the axial tip side, and the opposite direction is called the axial base end side. The direction orthogonal to the central axis O is called the radial direction, and the direction orbiting around the central axis O is called the circumferential direction. Also, the end on the axial tip side is called the tip, and the end on the axial base end side is called the base end. A predetermined radial direction is called the first radial direction, and a predetermined radial direction orthogonal to the first radial direction is called the second radial direction.

[0016] The main body part 2 is preferably formed of a resin material. The soft part 3 is preferably formed of a resin material, an elastomer material or a rubber material, and more preferably formed of an elastomer material.

[0017] The resin material forming the main body 2 is preferably polypropylene, polyethylene, ABS, polybutylene terephthalate, polycarbonate, polyethylene terephthalate, polystyrene, or polyacetal. Among these, from the viewpoint of strength, polypropylene, polyethylene, ABS, or polybutylene terephthalate is preferred, polypropylene, polyethylene, or ABS is more preferred, and polypropylene is even more preferred.

[0018] The elastomer material forming the soft portion 3 is preferably a styrene-based elastomer, silicone, olefin-based elastomer, or polyester-based elastomer. Among these, from the viewpoint of not damaging the gums, styrene-based elastomer, silicone, or olefin-based elastomer is preferred, styrene-based elastomer or olefin-based elastomer is more preferred, and styrene-based elastomer is even more preferred.

[0019] The hardness of the soft portion 3 is preferably 10 to 50 on the durometer hardness type A (JIS K6253), and more preferably 10 to 40. In this embodiment, the durometer hardness type A is 35.

[0020] The brush portion 3b has a predetermined number of rows of brush protrusions 3c, which are arranged circumferentially when viewed in the axial direction, and each row of brush protrusions 3c consists of a plurality of brush protrusions 3c1, which protrude radially outward from the outer surface of the peripheral wall 3a1.

[0021] The radial thickness t2 of the peripheral wall 3a1 at the base end of the peripheral wall 3a1 is less than or equal to the radial thickness t1 of the peripheral wall 3a1 at the tip end of the peripheral wall 3a1. The soft part 3 has a soft shaft connecting part 3d, which extends axially from the base end of the soft shaft part 3a along the base part 2a. The base part 2a has a main shaft part 2a2 and a plate-like part 2a1. The main shaft part 2a2 extends axially from the base end of the soft shaft part 3a, exposed on the surface, to the tip of the plate-like part 2a1. The plate-like part 2a1 has a plate width and plate thickness perpendicular to the axial direction. A predetermined number of brush projection rows 3c are provided, and the predetermined brush projection rows 3c protrude from the outer circumferential surface of the soft shaft part 3a along the plate width direction when viewed in the axial direction. The plate width direction is the second radial direction, and the thickness direction of the plate-like part 2a1 is the first radial direction perpendicular to the second radial direction.

[0022] The radial thickness t1 of the peripheral wall 3a1 at the tip of the peripheral wall 3a1 is not particularly limited, but is, for example, 0.05 to 0.20 mm. From the viewpoint of the strength of the soft part 3, it is preferably 0.08 to 0.18 mm, and more preferably 0.10 to 0.15 mm.

[0023] The radial thickness t2 of the peripheral wall 3a1 at the base end of the peripheral wall 3a1 is not particularly limited, but is, for example, 0.05 to 0.20 mm. From the viewpoint of the strength of the soft part 3, it is preferably 0.08 to 0.18 mm, and more preferably 0.10 to 0.15 mm.

[0024] The ratio (t1:t2) of the radial thickness t2 of the peripheral wall 3a1 at the base end to the radial thickness t1 of the peripheral wall 3a1 at the tip end of the peripheral wall 3a1 is not particularly limited, but is for example 1:0.5 to 1. From the viewpoint of reducing frictional resistance with the teeth T, it is preferably 1:0.7 to 0.95, and more preferably 1:0.8 to 0.93.

[0025] According to the above configuration, the radial thickness t2 of the peripheral wall 3a1 at the base end is less than or equal to the radial thickness t1 of the peripheral wall 3a1 at the tip end, so the displacement range that allows the peripheral wall 3a1 to elastically deform radially at the base end can be suppressed. Therefore, when the brush portion 3b is inserted deeply between the teeth, deformation of the peripheral wall 3a1 at the base end conforming to the surface shape of the tooth T (see dashed line in Figure 2) is suppressed, and the frictional resistance with the tooth T is reduced. However, because the deformation of the peripheral wall 3a1 is suppressed at the base end, when the brush portion 3b is pulled back after being inserted deeply between the teeth, as shown in Figures 7-8, the brush projection 3c1 at the base end of the peripheral wall 3a1 may be compressed radially between the tooth T and the peripheral wall 3a1, potentially increasing the resistance when pulling it back. In this regard, since the soft part 3 has a soft shaft connecting part 3d, as shown in Figure 9, the base of the brush projection 3c1 can be easily pulled in the retraction direction via the soft shaft part 3a, making it easier to tilt the brush projection 3c1 to the opposite side and suppressing the aforementioned resistance from becoming excessive.

[0026] Furthermore, by having the predetermined row of brush protrusions 3c that protrudes along the width direction of the plate, when cleaning the gap G between teeth, if the tooth T is positioned upward and the opposite side downward, the predetermined row of brush protrusions 3c protrudes upward, and the soft part 3 is moved axially in the gap G, the predetermined row of brush protrusions 3c slides and is guided by the adjacent teeth T at the upper end of the gap G, and because the frictional resistance with the teeth T is small at that time, the interdental cleaning tool 1 can be moved smoothly axially. However, because of this, if too much force is used during insertion, the tool may be inserted beyond the axial base end of the soft shaft part 3a, and the surface of that part may come into contact with the tooth 5 and rub against it. If the entire surface of that part were made up of the soft shaft connecting part 3d, damage would easily occur to that surface. However, since that surface is made up of the main shaft part 2a2, the occurrence of damage can be suppressed. Therefore, an interdental cleaning tool 1 with excellent cleaning performance and durability can be realized.

[0027] The interdental cleaning tool 1 has the following configuration to facilitate obtaining the above-mentioned effect. However, it may also have a configuration that includes only some of the following components.

[0028] The main shaft portion 2a2 extends axially towards the base end from the base end of the soft shaft portion 3a, exposed on the side surface in the plate width direction, to the tip of the plate-like portion 2a1. With this configuration, when cleaning the gap G, the side surface that is located above and is likely to come into contact with the teeth 5 is formed by the main shaft portion 2a2, thus further suppressing the occurrence of damage. The thickness (length in the first radial direction) of the main shaft portion 2a2 is, for example, 0.1 to 2.5 mm, preferably 0.15 to 1.5 mm, and more preferably 0.2 to 1.0 mm.

[0029] The main shaft portion 2a2 extends axially towards the base end from the base end of the soft shaft portion 3a, exposed on both sides in the plate width direction, to the tip of the plate-like portion 2a1. With this configuration, when cleaning the gap G, there is a risk that one of the two sides will be positioned above and come into contact with the teeth 5. However, since both sides are composed of the main shaft portion 2a2, the occurrence of damage can be further suppressed.

[0030] The main shaft portion 2a2 has a width that gradually increases in the axial direction toward the base end, from the tip of the base portion 2a to the tip of the plate-shaped portion 2a1. This configuration further suppresses the occurrence of damage.

[0031] The flexible shaft connecting portion 3d is exposed to the surface from the base end of the flexible shaft portion 3a and extends axially toward the base end. With this configuration, force can be easily transmitted from the flexible shaft connecting portion 3d to the brush portion 3b via the flexible shaft portion 3a. The thickness (length in the first radial direction) of the flexible shaft connecting portion 3d is not particularly limited, but is, for example, 0.05 to 0.20 mm. From the viewpoint of the strength of the flexible portion 3, it is preferably 0.08 to 0.18 mm, and more preferably 0.10 to 0.15 mm.

[0032] The flexible portion 3 has a gripping portion 3e, which at least partially covers a pair of main surfaces of the plate-like portion 2a1 that face opposite each other in the thickness direction, and the flexible shaft connecting portion 3d extends from the base end of the flexible shaft portion 3a, exposed on the side in the thickness direction, to the gripping portion 3e on the axial base end side. The flexible shaft connecting portion 3d has a first connecting portion 3d1 and a second connecting portion 3d2, and the gripping portion 3e has a first gripping portion 3e1 and a second gripping portion 3e2, the first gripping portion 3e1 at least partially covers one of the pair of main surfaces, the second gripping portion 3e2 at least partially covers the other of the pair of main surfaces, the first connecting portion 3d1 is exposed on one side in the thickness direction from the base end of the flexible shaft portion 3a and extends axially toward the base end to the first gripping portion 3e1, and the second connecting portion 3d2 is exposed on the other side in the thickness direction from the base end of the flexible shaft portion 3a and extends axially toward the base end to the second gripping portion 3e2. With this configuration, when inserting the brush portion 3b between teeth and pulling it back, the base of the brush projection 3c1 can be pulled further in the pulling direction. In other words, the tensile force can be effectively transmitted from the gripping portion 3e (first gripping portion 3e1 and second gripping portion 3e2) held by the user, via the flexible shaft connecting portion 3d (first connecting portion 3d1 and second connecting portion 3d2) and the flexible shaft portion 3a (circumferential wall 3a1).

[0033] The circumferential wall 3a1 has a row of holes 6 (see Figure 1) consisting of three holes 4 arranged along the axial direction. The first outer diameter d1 of the circumferential wall 3a1 at the first position, which is the axial position where the center of the furthest leading hole 4 of the row of holes 6 is located, is 0.6 mm or less, and the second outer diameter d2 of the circumferential wall 3a1 at the second position, which is the axial position where the center of the furthest proximal hole 4 of the row of holes 6 is located, is 1.1 mm or less. The holes 4 are recessed from the outer circumferential surface of the circumferential wall 3a1 to the outer circumferential surface of the axial core portion 2b, and the bottom surface 4a of the holes 4 is curved to form a single convex portion that protrudes radially outward when viewed in the axial direction (see Figure 3). The bottom surface 4a of the holes 4 is curved in an arc shape when viewed in the axial direction, but is not limited to this. The depth D2 of the furthest proximal hole 4 of the row of holes 6 (see Figure 3) is less than or equal to the depth D1 of the furthest leading hole 4 of the row of holes 6 (see Figure 5).

[0034] According to the above configuration, the peripheral wall 3a1 has a row of holes 6 consisting of three holes 4, the first outer diameter d1 is 0.6 mm or less, and the second outer diameter d2 is 1.1 mm or less, so the brush part 3b can be easily inserted into the interdental spaces of the molars, and the row of holes 6 of the soft shaft part 3a makes it easy to scrape plaque from the surface of the teeth T (see the dashed line in Figure 2).

[0035] Furthermore, according to the above configuration, the bottom surface 4a of the hole 4 is curved to form only one convex portion that protrudes radially outward when viewed in the axial direction, and the depth D2 of the most proximal hole 4 in the hole row 6 is less than or equal to the depth D1 of the most distal hole 4 in the hole row 6. Therefore, plaque that is received into the hole 4 from between the teeth and scraped out is prevented from sticking to the bottom of the hole 4, especially in the most proximal hole 4 of the hole row 6, making it impossible to remove from the hole 4.

[0036] The depth D1 of the outermost hole 4 in the row of holes 6 is not particularly limited, but is, for example, 0.05 to 0.20 mm. From the viewpoint of excellent cleanability and plaque removal, it is preferably 0.08 to 0.18 mm, and more preferably 0.10 to 0.15 mm.

[0037] The depth D2 of the most proximal hole 4 in the row of holes 6 is not particularly limited, but is, for example, 0.05 to 0.20 mm. From the viewpoint of excellent cleanability and plaque removal, it is preferably 0.08 to 0.18 mm, and more preferably 0.10 to 0.15 mm.

[0038] The ratio (D1:D2) of the depth D2 of the most proximal hole 4 in the hole row 6 to the depth D1 of the most distal hole 4 in the hole row 6 is not particularly limited, but is for example 1:0.5 to 1. From the viewpoint of excellent cleanability and plaque removal, it is preferably 1:0.7 to 0.95, and more preferably 1:0.8 to 0.93.

[0039] The peripheral wall 3a1 has a pair of hole rows 7 consisting of a pair of hole rows 6 (see Figure 2). The pair of holes 4 at the outermost tip of the hole row pair 7 are positioned on a straight line L perpendicular to the central axis O of the axial core portion 2b, with the holes themselves flanking the central axis O. The pair of holes 4 at the base of the hole row pair 7 are positioned on a straight line L perpendicular to the central axis O, with the periphery of the holes 4 flanking the central axis O. The remaining pair of holes 4 at the hole row pair 7 are positioned on a straight line L perpendicular to the central axis O, with the holes themselves flanking the central axis O. Each straight line L extends in the first radial direction. The pair of holes 4 at the outermost tip of the hole row pair 7 may be configured so that the periphery of the holes 4 is positioned on the straight line L flanking the central axis O. The pair of holes 4 at the base of the hole row pair 7 may be configured so that the holes themselves are positioned on the straight line L flanking the central axis O. The remaining pair of holes 4 in the hole row pair 7 may be configured such that the peripheral edges of the holes 4 are positioned on a straight line L, straddling the central axis O. When the holes of the pair of holes 4 are positioned on a straight line L, straddling the central axis O, the pair of holes 4 are on opposite sides of each other, allowing for efficient removal of plaque. When the peripheral edges of the pair of holes 4 are positioned on a straight line L, straddling the central axis O, the parts of the holes themselves of the pair of holes 4 that would otherwise have their core portion 2b exposed and reduced in strength are offset from each other in the axial direction, thus preventing the core portion 2b from breaking, especially when cleaning molars.

[0040] The peripheral wall 3a1 has a pair of holes 5, each consisting of a pair of holes 4, where the holes themselves or their peripheral edges are located on a straight line L perpendicular to the central axis O of the axial core portion 2b, with the holes flanking the central axis O. The peripheral wall 3a1 has a plurality of pairs of holes 5 arranged along the axial direction.

[0041] Hole 4 is a round hole. The depth direction of each hole 4 coincides with the first radial direction. The circumferential surface 4b of each hole 4 extends along the first radial direction.

[0042] The outer surface of the circumferential wall 3a1 gradually expands in diameter toward the axial base end. The inner surface of the circumferential wall 3a1 gradually expands in diameter toward the axial base end. The soft shaft portion 3a has a tip wall 3a2, which closes the tip of the circumferential wall 3a1. The circumferential wall 3a1 has a tapered cylindrical shape that narrows toward the axial tip end. The outer surface of the shaft core portion 2b gradually expands in diameter toward the axial base end. The shaft core portion 2b has a tapered cylindrical shape that narrows toward the axial tip end.

[0043] It is preferable that the first outer diameter d1 be 0.50 to 0.60 mm and the second outer diameter d2 be 1.00 to 1.10 mm, more preferably that the first outer diameter d1 be 0.53 to 0.60 mm and the second outer diameter d2 be 1.05 to 1.10 mm, and even more preferably that the first outer diameter d1 be 0.53 to 0.60 mm and the second outer diameter d2 be 1.05 to 1.08 mm.

[0044] Multiple brush protrusions 3c1 are arranged along the axial direction. Multiple brush protrusions 3c1 are arranged at equal intervals along the axial direction. The radial length of the brush protrusions 3c1 constituting the brush protrusion row 3c gradually increases toward the axial base end. A predetermined number of brush protrusion rows 3c are arranged at equal intervals in the circumferential direction when viewed in the axial direction. The brush protrusions 3c1 constituting the predetermined number of brush protrusion rows 3c are arranged on a helical track along the outer circumferential surface of the circumferential wall 3a1.

[0045] The predetermined number is 6 columns. However, the predetermined number may be more than 6 columns. For example, the predetermined number may be 8, 10, 12, 16, or 18 columns.

[0046] The predetermined number of brush projection rows 3c each consist of a pair of brush projection rows 3c, and when viewed in the axial direction, the pair of brush projection rows 3c protrude from the outer circumferential surface of the soft shaft portion 3a along the width direction of the plate toward opposite sides. With this configuration, as shown in Figure 6, when the user grasps the plate-shaped portion 2a1 and cleans the gap G, one of the pair of brush projection rows 3c protrudes upward and the other brush projection row 3c protrudes downward. Therefore, the upwardly protruding brush projection row 3c slides and is guided by the adjacent teeth T at the upper end of the gap G, while the downwardly protruding brush projection row 3c can clean the upper surface of the gingiva M facing the gap G, thereby further improving cleaning efficiency.

[0047] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and the embodiments described above can be modified in various ways without departing from the spirit of the present invention. [Explanation of Symbols]

[0048] 1. Interdental cleaning tools 2 Main body 2a base 2a1 Plate-like part 2a2 Main shaft 2b Axis center 3 Soft part 3a Soft shaft part 3a1 Surrounding wall 3a2 Tip wall 3b Brush part 3c Brush protrusion row 3c1 Brush protrusion 3D soft shaft connection 3d1 1st connection part 3d2 2nd connection part 3e Grip 3e1 1st grip part 3e2 2nd grip part 4 holes 4a Bottom 4b Peripheral surface 5 holes pair 6 hole row 7-hole row pair D1, D2 depth G Gap L straight line M Gum O center axis T tooth d1 1st outer diameter d2 2nd outer diameter t1, t2 Radial thickness

Claims

1. It has a main body and a soft part, The soft part is made of an elastic material having a hardness lower than that of the main body, and has a soft shaft portion and a brush portion. The aforementioned soft shaft portion extends in the axial direction and has a circumferential wall. The main body portion has a base portion and an axial core portion, The base portion extends from the base end of the soft shaft portion toward the axial base end, The shaft core extends from the tip of the base into the circumferential wall of the soft shaft and is in close contact with the inner surface of the circumferential wall. The brush portion has a predetermined number of rows of brush protrusions, The predetermined number of brush protrusion rows are arranged in the circumferential direction when viewed in the axial direction. The aforementioned row of brush protrusions consists of multiple brush protrusions, The brush projection is an interdental cleaning tool that protrudes radially outward from the outer surface of the peripheral wall, The radial thickness of the peripheral wall at the base end of the peripheral wall is less than or equal to the radial thickness of the peripheral wall at the tip end of the peripheral wall. The aforementioned soft part has a soft shaft connecting part, The flexible shaft connecting portion extends from the base end of the flexible shaft portion toward the axial base end, The base portion has a main shaft portion and a plate-shaped portion. The main shaft portion extends from the base end of the soft shaft portion to the tip of the plate-like portion, exposed on the surface, towards the base end in the axial direction. The plate-like portion has a width and thickness perpendicular to the axial direction. The predetermined number of brush protrusion rows have a predetermined number of brush protrusion rows. An interdental cleaning tool wherein the predetermined row of brush protrusions protrudes from the outer circumferential surface of the soft shaft portion along the width direction when viewed in the axial direction.

2. The interdental cleaning tool according to claim 1, wherein the main shaft portion extends from the base end of the soft shaft portion to the tip of the plate-shaped portion, exposed on the surface on the side in the width direction of the plate, toward the axial base end.

3. The interdental cleaning tool according to claim 1, wherein the main shaft portion extends axially toward the base end from the base end of the soft shaft portion, exposed on both sides in the width direction of the plate, to the tip of the plate-like portion.

4. The peripheral wall has a row of holes consisting of three holes arranged along the axial direction, The first outer diameter, which is the outer diameter of the peripheral wall at the first position, which is the axial position where the center of the hole at the very front of the row of holes is located, is 0.6 mm or less, and the second outer diameter, which is the outer diameter of the peripheral wall at the second position, which is the axial position where the center of the hole at the very base of the row of holes is located, is 1.1 mm or less. The aforementioned hole is recessed from the outer surface of the peripheral wall to the outer surface of the axial core, The bottom surface of the hole is curved to form a single protrusion that projects radially outward when viewed in the axial direction. The interdental cleaning tool according to claim 1, wherein the depth of the hole at the most proximal end of the row of holes is less than or equal to the depth of the hole at the most distal end of the row of holes.

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