Tuft type toothbrush

Abstract

To provide a tuft type toothbrush that can effectively clean the crowding part and the like of teeth, reduce harmfulness during brushing, and hold a cost of manufacture low.SOLUTION: A tuft type toothbrush 1 includes: a handle part 2 that is held by a hand; a neck part 3 extending from the handle part 2 to a tip side; and a cleaning part 4 installed on the tip side of the neck part 3 and comprising a head part 6 to which a bristle bundle 5 is planted. At least the tip side part 32 of the neck part 3 which is connected to the head part 6 includes: a neck base material part 33 made of a synthetic resin; and a neck soft part 34 covering at least part of the neck base material part 33 and made of an elastomer.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a tuft-type toothbrush in which bristle bundles each having a plurality of filaments bound together are implanted in bristle implantation holes. [Background technology]

[0002] Conventionally, single-tuft toothbrushes, which have a bristle bundle made of multiple filaments bound together and planted in a single bristle hole in the head, have been known as toothbrushes suitable for cleaning periodontal pockets and crowded areas (areas where teeth are misaligned) where brushing is likely to be left unbrushed (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-186672 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, while the above-mentioned tufted toothbrush can effectively clean crowding of teeth, the tips of the bristles may damage the gums. For this reason, the tufted toothbrush of Patent Document 1 has a small diameter filament that constitutes the bristles, making the bristles soft, thereby reducing the damage caused by brushing. However, this method limits the filaments that can be used, increases manufacturing costs, and may result in the bristles being too soft, reducing cleaning performance.

[0005] The present invention has been made in consideration of the above points, and aims to provide a tufted toothbrush that can effectively clean crowded areas of teeth, reduce harmful effects during brushing, and can be manufactured at low costs. [Means for solving the problem]

[0006] The present invention is a tufted toothbrush comprising a handle portion to be held by the user, a neck portion extending from the handle portion toward the tip side, and a cleaning portion consisting of a head portion provided at the tip side of the neck portion and having tufts of bristles planted therein, wherein at least the tip side portion of the neck portion connected to the head portion has a neck base material portion made of a synthetic resin and a neck soft portion made of an elastomer that covers at least a part of the neck base material portion. In the present invention, elastomer refers to a material having rubber elasticity, and includes thermoplastic elastomers and thermosetting elastomers (various types of rubber).

[0007] According to this configuration, by bending the tip end of the neck portion when brushing, it is possible to effectively reduce irritation to the teeth, etc., while properly cleaning the crowded areas of the teeth, etc. Therefore, it is possible to prevent damage to the gums, etc., and reduce the harmful effects.

[0008] It is also preferable that the neck soft portion is configured to cover at least the ventral surface of the neck base material, which is the direction in which the hair bundle protrudes, and the dorsal surface on the opposite side.

[0009] In this case, by bending the tip end portion of the neck during brushing, irritation to the teeth, etc. can be more effectively reduced, and the filaments of the bristle bundle can be brought into close contact with the tooth surface, etc., improving cleaning performance. In addition, since the tip end portion of the neck is flexible, it can soften the impact when it comes into contact with the lips, etc., which has the advantage of effectively preventing the user from feeling uncomfortable.

[0010] The neck base material portion may be configured in the shape of an elongated shaft, and the neck soft portion may cover the entire periphery of the neck base material portion.

[0011] In this case, the improvement in flexibility and suppleness and the reduction in irritation can be more reliably achieved.

[0012] It is also preferable that the head portion comprises a head base material portion made of synthetic resin having a bent or curved shape on the ventral side, which is continuous with the tip of the neck base material portion, and a head soft portion made of elastomer covering at least a portion of the head base material portion and formed continuously with the neck soft portion.

[0013] In this case, the head part as well as the neck part can be made flexible and the flexibility can be increased, so that the head part and the neck part can be effectively made flexible during brushing, which can more effectively reduce irritation to the teeth, etc., and further reduce harmfulness. In addition, there is an advantage that the impact when it comes into contact with the lips, etc. during use can be further softened, and discomfort to the user can be more effectively prevented. Moreover, the necessary rigidity of the head part can be maintained compared to when the entire head part is made of elastomer, and deterioration of cleaning performance caused by excessive bending of the head part during brushing can be prevented.

[0014] It is also preferable that a cylindrical hair bundle support base is provided at the tip of the head portion, the hair bundle support base having an opening for a hair implantation hole for supporting the hair bundle and protruding ventrally beyond the neck portion, and at least a portion of the peripheral wall of the hair bundle support base is configured by a soft wall made of the elastomer formed continuously with the head soft portion.

[0015] In this case, the flexibility of the head portion can be increased compared to when the entire head portion is made of synthetic resin, and the simple configuration allows the head portion to flex more effectively when brushing, effectively reducing irritation to the teeth, etc.

[0016] It is also preferable that the soft wall is provided on a wall portion on the neck side when the bristle bundle support base is viewed in a plan view from the axial direction.

[0017] In this case, by providing a soft wall at the portion where the wall of the bristle bundle support stand is likely to come into contact with the lips, etc., during brushing, it is possible to further soften the contact with the lips, etc., and further increase safety. Furthermore, by providing a soft wall on the wall on the neck side, the wall stretches during brushing, making the head part more likely to bend toward the back side, and more effectively reducing irritation to the teeth, etc.

[0018] It is also preferable that the soft wall is provided in an area of ​​less than 180° in a plan view of the bristle bundle support base from the axial direction. It is also preferable that the peripheral wall of the bristle bundle support base is composed of the soft wall and a base wall made of a synthetic resin formed continuously with the head base material, and that the base wall is provided in an area of ​​180° or more in a plan view of the bristle bundle support base from the axial direction.

[0019] In this case, the bristle bundle support base's bristle implantation holes can be prevented from widening during brushing, and the strength of the bristle bundle and bristles can be maintained. In particular, when the bristle bundle is fixed to the bristle bundle support base using a flat wire, both ends of the flat wire can be inserted into the hard head base material, so that the flat wire can be firmly fixed and the strength of the bristle bundle and bristles can be easily maintained.

[0020] It is also preferable that the tufts of hair are attached to the head portion by flat lines arranged so that the plate surface extends in a direction intersecting at an angle greater than 45 degrees with respect to an axis along the extension direction of the neck portion.

[0021] In this case, it is possible to prevent the flat line from hindering the bending of the bristle bundle support base in the direction along the extension direction of the neck part, and therefore, by actively bending the bristle bundle support base in the direction along the extension direction of the neck part when brushing, it is possible to effectively reduce irritation to the teeth, etc.

[0022] Also, it is preferable that the hair brush be of a one-tuft type in which only one tuft of hair is implanted in the head portion.

[0023] In this case, in a one-tuft type tactile toothbrush that can effectively clean crowded areas of the teeth with a single bundle of bristles, irritation to the teeth, etc. can be effectively reduced by bending the tip portion of the neck when brushing. Effect of the Invention

[0024] The tufted toothbrush according to the present invention has the advantages of being able to effectively clean crowded areas, reducing the harm caused by brushing, and keeping manufacturing costs low. [Brief description of the drawings]

[0025] [Figure 1] FIG. 1 is a perspective view of a tufted toothbrush according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a side cross-sectional view showing a main portion of the tufted toothbrush. [Diagram 3] Cross-sectional view of line III-III in Figure 2. [Figure 4] FIG. 4 is a side view showing the configuration of a primary molded product made of synthetic resin. [Diagram 5] FIG. 2 is a plan cross-sectional view showing the main parts of a tufted toothbrush. [Figure 6] Cross-sectional view taken along line VI-VI in Figure 1. [Figure 7] FIG. [Figure 8] FIG. 4 is a cross-sectional view showing a modified example of the tufted toothbrush according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a tufted toothbrush according to the present invention will be described with reference to the drawings. In each drawing, the same reference numerals are used to denote the same configuration, and the description thereof will be omitted.

[0027] 1 to 6 show a tufted toothbrush 1 according to a representative embodiment of the present invention. This tufted toothbrush 1 comprises a handle portion 2 which serves as a grip, a neck portion 3 provided contiguous to the tip side of the handle portion 2, and a cleaning portion 4 provided contiguous to the tip side of the neck portion 3. The cleaning portion 4 comprises a head portion 6 in which bristle bundles 5 are implanted, and at the tip of the head portion 6, as shown in Figs. 5 and 6, a bristle implantation hole 63 for supporting the bristle bundle 5 is opened, and a cylindrical bristle bundle support base 64 is provided which protrudes from the neck portion 3 toward the ventral side, which is the protruding direction of the bristle bundle 5.

[0028] In particular, at least the tip end portion 32 of the neck portion 3 connected to the head portion 6 has a neck base material portion 33 made of a synthetic resin and a neck soft portion 34 made of an elastomer that covers at least a part of the neck base material portion 33, and thus, by bending the tip end portion 32 of the neck portion 3 during brushing, it is possible to effectively reduce irritation to the teeth, etc., while properly cleaning the crowding of teeth, and to suppress damage to the gums, etc., thereby reducing harmfulness. The range along the axial direction of the tip end portion 32 in which the neck soft portion 34 exists is preferably 5 mm or more and 30 mm or less from the tip of the neck portion 3 to the base end side, as this is a range in which the harmfulness reducing function can be sufficiently obtained and the neck portion 3 does not become too soft and can sufficiently ensure excellent cleaning properties.

[0029] The shape and dimensions of the handle portion 2 can be set to any shape and dimensions as long as it can be gripped and operated by hand. The neck portion 3 has a tapered shape in which the diameter gradually decreases from the handle portion 2 toward the tip side.

[0030] In this embodiment, as shown in Figs. 2 to 4, the tip end portion 32 of the neck portion 3 is composed of a neck base material portion 33 formed in a long and thin rod shape and a neck soft portion 34 made of a cylindrical elastomer that covers the entire circumference of the neck base material portion 33. By changing the ratio between the diameter of the neck base material portion 33 and the thickness (covering thickness) of the neck soft portion 34 made of an elastomer, it is possible to obtain a degree of flexibility of the tip end portion of the neck portion 3 according to the user's preference. The diameter of the neck base material portion 33 is preferably within a range of 1 mm to 3 mm, and the thickness of the neck soft portion 34 is preferably within a range of 0.8 mm to 1.5 mm. The ratio between the diameter of the neck base material portion 33 and the thickness of the neck soft portion 34 ((diameter of the neck base material portion 33) / (thickness of the neck soft portion 34)) is preferably within a range of 0.66 to 3.75. By setting it within this range, a balance between cleanability and harmfulness is achieved, and moldability is also good.

[0031] In this example, the neck soft part 34 covers the entire circumference as described above, but the present invention is not limited to this, and preferably, as long as the neck soft part 34 covers at least the ventral surface of the neck base material part 33 in the direction in which the hair bundle protrudes, and the dorsal surface on the opposite side, it is effective even if it does not cover the left and right side surfaces, as will be described later.

[0032] For example, as shown in Fig. 8, a neck base material 33a of a neck tip side portion 32a may be formed in a flat plate shape, and a neck soft portion 34a may be provided to cover the ventral surface in the protruding direction of the hair bundle 5, and a neck soft portion 34b may be provided to cover the dorsal surface located opposite to the ventral surface. With this configuration, it is possible to increase the flexibility of the tip side portion 32 of the neck portion 3 in the up-down direction in Fig. 6, i.e., the direction along the protruding direction of the hair bundle 5, compared to the left-right direction in Fig. 8, i.e., the direction perpendicular to the protruding direction of the hair bundle 5.

[0033] Therefore, by bending the tip end portion 32 of the neck portion 3 greatly in the direction along the protruding direction of the bristle bundle 5 during brushing, irritation to the teeth, etc. can be more effectively alleviated. Moreover, since the tip end portion 32 of the neck portion 3 is prevented from bending greatly in the direction perpendicular to the protruding direction of the bristle bundle 5 during brushing, wobbling of the head portion 6 is suppressed and cleaning performance is improved.

[0034] Here, instead of exposing both the left and right end faces of the neck base material 33a to the outside, it is also possible to cover both the left and right end faces of the neck base material 33a with a neck soft part as shown in Fig. 8. However, when both the left and right end faces of the neck base material 33a are exposed to the outside as described above, there is an advantage in that a design different from the usual one can be obtained by, for example, coloring the neck base material 33a made of synthetic resin and the neck soft parts 34a and 34b made of elastomer in different colors.

[0035] The head portion 6 comprises a head substrate portion 61 made of synthetic resin that is continuous with the tip of the neck substrate portion 33 and has a bent or curved shape on the ventral side of the tufted toothbrush 1, and a head soft portion 62 made of elastomer that is continuous with the neck soft portion 34 and covers at least a portion of the head substrate portion 61. In this example, the head substrate portion 61 has an L-shaped bent shape, but is not limited to this and may have other shapes, such as a curved arc shape.

[0036] The peripheral wall of the bristle bundle support base 64 provided at the tip of the head portion 6 is composed of a base wall 65 which is part of the neck base material 33, and a soft wall 66 which is made of an elastomer and is continuous with the head soft portion 62. As shown in Fig. 5, the base wall 65 is configured in a substantially C-shape excluding a part on the neck portion 3 side when the bristle bundle support base 64 is viewed in a plan view from the axial direction. One soft wall 66 configures a partial area of ​​the bristle bundle support base 64 located on the neck portion 3 side.

[0037] This makes it possible to improve safety by softening the impact when the wall of the bristle bundle support base 64 comes into contact with the lips, etc., during brushing. Also, the flexibility of the bristle bundle support base 64 can be increased in the left-right direction in Fig. 5, i.e., in the extension direction of the neck portion 3, compared to the up-down direction in Fig. 5, i.e., the direction perpendicular to the extension direction of the neck portion 3, during brushing. Therefore, by bending the bristle bundle support base 64 greatly in the extension direction of the neck portion 3, irritation to the teeth, etc., can be effectively reduced during brushing.

[0038] The base wall 65 preferably constitutes an area of ​​180° or more, and more preferably an area of ​​240° to 300°, of the tufting hole 63. This allows the base wall 65 to firmly support both ends of the flat wire 7 that fixes the tuft 5 to the tuft support base 64 while increasing the flexibility of the tuft support base 64.

[0039] The soft wall 66 is formed in a short arc shape corresponding to the spaced apart portion of the base wall 65, and the soft wall 66 forms an area of ​​the tufting hole 63 that is preferably less than 180°, and more preferably an area of ​​60° to 120°. This increases the flexibility of the tuft support base 64 while allowing the tips of the tufts 5 to come into close contact with the tooth surface, etc., improving cleaning performance.

[0040] Moreover, if the diameter of the tufting holes 63 in the tuft support base 64 is too small, the cleaning efficiency decreases, and if it is too large, the harmfulness increases, so it is preferable to set the diameter to 3 mm or more and 6 mm or less.

[0041] As described above, in the tufted toothbrush 1 of this embodiment, the handle portion 2, the neck substrate portion 33 constituting the tip portion 32 and the portion 31 excluding the tip portion 32 of the neck portion 3, and the head substrate portion 61 including the substrate wall 65 constituting the bristle bundle support base 64 are integrally molded using synthetic resin, and on top of this, the neck soft portion 34, the head soft portion 62, and the soft wall 66 constituting the bristle bundle support base 64 are integrally molded using elastomer.

[0042] The synthetic resin used in the above molding may be an olefin resin, a polyamide resin, a saturated polyester resin, a polymethyl methacrylate resin, a cellulose propionate resin, a thermoplastic polyurethane resin, a polycarbonate resin, a polyacetal resin, an ABS (Acrylonitrile Butadiene Styrene) resin, or the like.

[0043] In addition, the elastomer used in the above molding can be a wide variety of flexible resins or rubbers. As the thermoplastic elastomer, polystyrene-based thermoplastic elastomers, polyolefin-based thermoplastic elastomers, polyurethane-based thermoplastic elastomers, polyester-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, 1,2-polybutadiene-based thermoplastic elastomers, ethylene-vinyl acetate-based thermoplastic elastomers, polyvinyl chloride-based thermoplastic elastomers, natural elastomer-based thermoplastic elastomers, fluorine elastomer-based thermoplastic elastomers, trans-polyisoprene-based thermoplastic elastomers, chlorinated polyethylene-based thermoplastic elastomers, etc. can be suitably used. In addition, as the thermosetting elastomer, natural rubber, silicone rubber, fluorine-based rubber, styrene rubber, urethane rubber, and other thermosetting elastomers can also be used.

[0044] The bristle bundle 5 is fixed by folding the filament 5a in half as shown in Fig. 6, inserting a metallic flat wire 7 (see the imaginary line in Fig. 5) inside the folded part in a state of being arranged in a direction substantially perpendicular to the extension direction of the neck part 3, and then implanting and fixing the bristle bundle 5 together with the flat wire 7 in the bristle implantation hole 63. In the above embodiment, the plate surface of the flat wire 7 is arranged in a direction substantially perpendicular to the extension direction of the neck part 3, but instead of this configuration, it is also possible to arrange the plate surface of the flat wire 7 in a direction along the extension direction of the neck part 3. However, in this configuration, the bending of the bristle bundle support base 64 in the direction along the extension direction of the neck part 3 may be hindered by the flat wire 7, and the effect of suppressing irritation to the teeth, etc. tends to decrease. For this reason, as shown in Figure 5, it is preferable to arrange the plate surface of the flat wire 7 so that it extends in a direction that intersects with the axis along the extension direction of the neck portion 3 at an angle greater than 45 degrees, and more preferably so that it extends in a direction that is approximately perpendicular to the axis along the extension direction of the neck portion 3, so that the bristle bundle support base 64 is actively bent in the direction along the extension direction of the neck portion 3 during brushing, thereby reducing irritation to the teeth, etc.

[0045] However, the present invention is not limited to fixing the hair bundle with a flat wire. For example, various known methods can be used, such as a method of forming a molten mass at the base end of the filament 5a and embedding and fixing the molten mass integrally to the head part 6, a method of forming a molten mass at the base end of the hair bundle 5 formed by bundling multiple filaments 5a and fixing the hair bundle 5 to the head part 6 using a fixing member that fits around the molten mass, or a method of using an adhesive.

[0046] The material of the filament 5a may be, for example, polyamide resins such as nylon and aramid resin, polyester resins such as polyethylene terephthalate, polytrimethylene terephthalate, or polybutylene terephthalate, polyolefin resins such as polypropylene, thermoplastic elastomer resins, or other known materials.

[0047] The cross-sectional shape of the filament 5a constituting the bristle bundle 5 is preferably circular, but filaments of various cross-sectional shapes such as triangular and rectangular can also be used, and composite filaments with a core-sheath structure can also be used. The diameter of the filament 5a is preferably 0.08 mm to 0.2 mm in order to achieve gentle contact with teeth and ability to reach between teeth.

[0048] The tip of the bristle bundle 5 is cut into a cone shape as shown in Fig. 6. The apex angle θ1 of the cone in a side view of the tip of the bristle bundle 5 is set to 30° to 70°. This allows the bristle bundle 5 to fit into the gaps in the oral cavity and improve cleaning performance while reducing harmful effects. The bristle length H of the bristle bundle 5 exposed from the bristle implantation hole 63 is preferably set to 6 mm or more and 12 mm or less in order to achieve gentle contact with teeth and good interdental reach.

[0049] Next, a manufacturing procedure for the tufted toothbrush 1 according to this embodiment will be described.

[0050] First, a primary mold having a space for molding the primary molded product 11 (see Figure 4) in which the handle portion 2 of the tufted toothbrush 1, the base end portion 31 and neck substrate portion 33 of the neck portion 3, and the head substrate portion 61 of the head portion 6 are integrally connected is clamped, and molten synthetic resin is injected into this primary mold to mold the primary molded product 11.

[0051] Next, the primary mold is opened to remove the primary molded product 11, and the primary molded product 11 is set in a secondary mold having spaces for forming the neck soft portion 34 of the neck portion 3, the head soft portion 62 of the head portion 6, and the soft wall 66. Then, with the secondary mold closed, molten elastomer is injected into the secondary mold to form the secondary molded product 12 consisting of the neck soft portion 34, the head soft portion 62, and the soft wall 66 (see FIG. 2). In this manner, a toothbrush body is formed in which the neck portion 3 and part of the head portion 6 of the primary molded product 11 made of synthetic resin are covered with elastomer.

[0052] 6, a required number of filaments 5a, for example 200 filaments 5a, are bundled and folded in two, and with the flat wire 7 placed inside the folded part, they are pushed into the tufting hole 63 of the tuft support base 64 and fixed in the tufting hole 63. In this case, as shown by the imaginary lines in FIG. 5, by having both ends of the flat wire 7 bite into the inner wall surface of the base material wall 65 of the tuft support base 64, it is possible to ensure sufficient holding strength for the tuft 5.

[0053] Next, as shown in Figure 7, using a cutting device 8 having a cylindrical cutting head 82 with a mortar-shaped recess 80 formed on the bottom surface and multiple blades 81 radially arranged at intervals around the inner surface of the recess 80, and a motor 83 for rotating the cutting head 82 about its axis, the recess 80 of the cutting head 82 is fitted into the tip of the hair bundle 5 from above, and the tip of the hair bundle 5 planted in the hair planting hole 63 is cut into a cone shape using the blade 81 provided on the cutting head 82, as shown in Figure 6.

[0054] In this embodiment, the head substrate 61 made of synthetic resin is provided continuous with the tip of the neck substrate 33, so that when the neck substrate 33 and the head substrate 61 are molded using a primary molding die or the like, they can be molded easily and continuously. Also, the head soft portion 62 and the soft wall 66 made of elastomer are provided continuous with the tip of the neck soft portion 34, so that when the neck soft portion 34, the head soft portion 62 and the soft wall 66 are molded using a secondary molding die or the like, they can be molded easily and continuously, which has the advantage of effectively improving the productivity of the tufted toothbrush 1.

[0055] Although an embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and it is needless to say that the configuration can be modified without departing from the gist of the present invention.

[0056] For example, instead of the soft wall 66 of the bristle bundle support base 64, it is also preferable to extend a head substrate 61 thinner than the head substrate 61 constituting the substrate wall 65 on the inner peripheral side, thereby disposing the head substrate 61 all around the bristle bundle support base 64, and to cover the thin head substrate 61 with a head soft portion 62. Also, an elastomer covering portion can be provided on the portion 32 of the handle portion 2 and the neck portion 3 on the base end side from the tip portion 32.

[0057] Also, in the above embodiment, a single tufted toothbrush 1 having only one bristle bundle 5 planted in the head portion 6 has been described, but the present invention can also be applied to a tufted toothbrush (general toothbrush) having a bristle bundle 5 planted in each of a plurality of bristle planting holes 63 provided in the head portion 6. However, since it is more difficult to reduce harmful effects while maintaining cleaning performance with a single tufted toothbrush 1 compared to a general toothbrush, there is a greater benefit in applying the present invention.

[0058] Furthermore, the present invention can be applied to an electric tufted toothbrush. In this case, similar to a known electric toothbrush, a replacement brush and a handle having a drive means for driving the replacement brush are provided, and the neck portion 3 and head portion 6 are provided on the replacement brush. The cleaning portion 4 is formed by attaching the bristle bundle 5 to the bristle bundle support base 64. [Explanation of symbols]

[0059] 1 Tufted toothbrush 2 Handle 3 Neck 4 Cleaning Department 5 Hair bundle 5a filament 6 Head section 7. Flat Line 8 Cutting equipment 11 Primary molded product 31 Part other than the tip 32 Tip side part 33, 33a Neck base material 34, 34a, 34b Neck soft part 66 Soft wall 61 Head base material 62 Head soft part 63 Hair transplant hole 64 Hair bundle support stand 65 Base material wall 66 Soft wall

Claims

1. A tufted toothbrush comprising a handle portion to be held by the user, a neck portion extending from the handle portion toward the tip end, and a cleaning portion formed of a head portion provided at the tip end of the neck portion and having tufts of bristles attached thereto, A tufted toothbrush characterized in that at least the tip portion of the neck portion connected to the head portion has a neck base material portion made of synthetic resin and a neck soft portion made of elastomer covering at least a portion of the neck base material portion.

2. 2. The tufted toothbrush according to claim 1, wherein said neck soft portion covers at least a ventral surface of said neck base material in a direction in which said bristle bundles protrude, and a dorsal surface opposite said ventral surface.

3. 3. The tufted toothbrush according to claim 2, wherein the neck base material is configured in the shape of an elongated shaft, and the neck soft portion covers the entire circumference of the neck base material.

4. The head portion is A head base material portion made of a synthetic resin and provided continuously to the tip of the neck base material portion and having a bent or curved shape toward the ventral side; 2. The tufted toothbrush according to claim 1, further comprising a head soft portion made of an elastomer covering at least a portion of the head base material and formed contiguous with the neck soft portion.

5. A cylindrical hair bundle support base is provided at a tip of the head portion, the hair bundle support base having a hair implantation hole for supporting the hair bundle and protruding ventrally beyond the neck portion, 5. The tufted toothbrush according to claim 4, wherein at least a portion of the peripheral wall of said bristle bundle support base is formed of a soft wall made of an elastomer which is continuous with said head soft portion.

6. 6. The tufted toothbrush according to claim 5, wherein the soft wall is provided on a wall portion on the neck side when viewed in a plan view of the bristle bundle support base from the axial direction.

7. 6. The tufted toothbrush according to claim 5, wherein the soft wall is provided in an area that is less than 180° in a plan view of the bristle bundle support base in the axial direction.

8. 2. The tufted toothbrush of claim 1, wherein the tufts are attached to the head portion by flat lines arranged so that the plate surface extends in a direction intersecting at an angle greater than 45 degrees with respect to an axis along the extension direction of the neck portion.

9. 2. The tufted toothbrush according to claim 1, which is a one-tuft type toothbrush having only one tuft of bristles attached to the head portion.

Images