Interdental cleaning tools

Abstract

To provide an interdental cleaning tool with excellent cleanability. [Solution] An interdental cleaning tool having a main body and a soft part, the soft part having a soft shaft and a brush part, the soft shaft having a peripheral wall, the main body having a base 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 base has a main shaft and a plate-like part, the soft part has an elastic connecting part, the elastic connecting part connects the base end of the main shaft and the tip of the plate-like part, the predetermined number of rows of brush protrusions have predetermined rows of brush protrusions, the predetermined rows of brush protrusions protrude from the outer peripheral surface of the soft shaft along the plate width direction.

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 axial proximal end side. 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 brush protrusion rows. The predetermined number of brush protrusion rows are arranged in the circumferential direction when viewed in the axial direction. The brush protrusion row consists of a plurality of brush protrusions, and the brush protrusions protrude radially outward from the outer peripheral surface of the peripheral wall (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 between teeth is important.

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

Means for Solving the Problems

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

[0007] [1] 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, 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 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 toward the axial base end, The aforementioned soft part has an elastic connecting part, The elastic connecting portion connects the base end of the main shaft portion and the tip of the plate-shaped portion, which are spaced apart from each other 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 aforementioned soft part has a soft shaft connecting part, The interdental cleaning tool according to [1], wherein the flexible shaft connecting portion extends axially toward the base end from the base end of the flexible shaft portion to the elastic connecting portion along the base.

[0009] [3] The soft shaft connecting part is the interdental cleaning tool according to [2], which extends from the base end of the soft shaft part to the surface and reaches the elastic connecting part on the base end side in the axial direction.

[0010] [4] The peripheral wall has a row of holes consisting of three holes arranged along the axial direction. A first outer diameter, which is the outer diameter of the peripheral wall at a first position that is the axial position where the center of the hole on the most distal side of the row of holes is located, is 0.6 mm or less, and a second outer diameter, which is the outer diameter of the peripheral wall at a second position that is the axial position where the center of the hole on the most proximal side of the row of holes is located, is 1.1 mm or less. The holes are recessed from the outer peripheral surface of the peripheral wall to the outer peripheral surface of the axial core part. The bottom surface of the hole is curved so as to form only one convex part that protrudes outward in the radial direction when viewed in the axial direction. The depth of the hole on the most proximal side of the row of holes is not more than the depth of the hole on the most distal side of the row of holes. The interdental cleaning tool according to any one of [1] to [3].

Effect of the Invention

[0011] According to the present invention, an interdental cleaning tool excellent in cleaning performance 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 a first radial direction, and (b) is an external view of the interdental cleaning tool shown in (a) as viewed from a second radial direction. [Figure 2] It is a cross-sectional view taken along the line A - A of FIG. 1(a). [Figure 3] It is a cross-sectional view taken along the line B - B of FIG. 1(a). [Figure 4] It is a cross-sectional view taken along the line C - C of FIG. 1(a). [Figure 5] It is a cross-sectional view taken along the line D - D of FIG. 1(a). [Figure 6] It is an explanatory view for explaining the state of use of the interdental cleaning tool shown in FIG. 1. [Figure 7]It is a cross-sectional view showing a state when inserting a brush part into a gap between teeth shown in FIG. 6. [Figure 8] It is a cross-sectional view showing a state when starting to pull back the brush part from the state of FIG. 7. [Figure 9] It is a cross-sectional view showing a 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 illustrated and described with reference to the drawings.

[0014] As shown in FIGS. 1 to 5, in one embodiment of the present invention, the interdental cleaner 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, and 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 a shaft extending细长ly 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 base portion 2a has a main shaft portion 2a2 and a plate-like portion 2a1. The main shaft portion 2a2 extends from the base end of the soft shaft portion 3a toward the axial base end. The soft portion 3 has an elastic connecting portion 3f, which connects the base end of the main shaft portion 2a2 and the tip of the plate-like portion 2a1, which are spaced apart from each other in the axial direction. The plate-like portion 2a1 has a plate width and plate thickness perpendicular to the axial direction. A predetermined number of brush projection rows 3c are provided, and these predetermined brush projection rows 3c protrude from the outer circumferential surface of the soft shaft portion 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 portion 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 in which the peripheral wall 3a1 can be elastically deformed 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. 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. Moreover, when cleaning the gaps between teeth, not just the anterior teeth, the elastic connecting part 3f can be elastically deformed and bent in the thickness direction in the part between the base end of the main shaft part 2a2 and the tip of the plate-like part 2a1, as shown by the dashed line in Figure 1(b), so that the molars can also be cleaned smoothly.Therefore, the interdental cleaning tool 1 can be cleaned smoothly between teeth G in both the anterior and molars, and an interdental cleaning tool 1 with excellent cleaning performance can be realized.

[0026] 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.

[0027] 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 2a to the elastic connecting part 3f. Since deformation of the circumferential wall 3a1 is suppressed at the base end of the circumferential wall 3a1, when the brush part 3b is pulled back after being deeply inserted between teeth, as shown in Figures 7-8, the brush projection 3c1 at the base end of the circumferential wall 3a1 may be compressed radially between the tooth T and the circumferential wall 3a1, potentially increasing the resistance when pulling it back. In this regard, by having a soft shaft connecting part 3d that connects the base end of the soft shaft part 3a and the elastic connecting part 3f in the soft part 3, as shown in Figure 9, the base of the brush projection 3c1 can be easily pulled back via the soft shaft part 3a, making it easier to tilt the brush projection 3c1 to the opposite side, thus suppressing excessive resistance. Therefore, cleaning performance can be improved.

[0028] The flexible shaft connecting portion 3d extends axially towards the base end from the base end of the flexible shaft portion 3a, exposed on the surface, to the elastic connecting portion 3f. This configuration facilitates the transmission of force 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.

[0029] 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).

[0030] The main shaft portion 2a2 and the elastic connecting portion 3f, as a whole, have a gradually increasing width in the plate width direction from the tip of the base portion 2a to the tip of the plate-like portion 2a1 toward the axial base end. 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.

[0031] 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).

[0032] 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).

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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]

[0046] 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 3f Elastic joint 4 holes 4a Bottom 4b Peripheral surface 5 holes pair 6 hole row 7-hole row pair G Gap D1, D2 depth 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 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 toward the axial base end, The aforementioned soft part has an elastic connecting part, The elastic connecting portion connects the base end of the main shaft portion and the tip of the plate-shaped portion, which are spaced apart from each other 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 aforementioned soft part has a soft shaft connecting part, The interdental cleaning tool according to claim 1, wherein the flexible shaft connecting portion extends axially toward the base end from the base end of the flexible shaft portion along the base to the elastic connecting portion.

3. The interdental cleaning tool according to claim 2, wherein the flexible shaft connecting portion extends from the base end of the flexible shaft portion to the elastic connecting portion, exposed on the surface, and extending axially toward the base end.

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.

Images