Toothbrush with novel bristle structure

Abstract

The present disclosure provides a toothbrush head and a toothbrush having an improved toothbrush bristle configuration that includes different types of bristle filaments in a specific arrangement. Disclosed is a toothbrush head (10) connected or connectable to a handle (20) to define a head-handle longitudinal direction (L-L) and a transverse direction (W-W) perpendicular to the longitudinal direction (L-L), the head (10) having a bristle surface (12) with a distal end (12A) distal from the handle (20), a proximal end (12B) closer to the handle (20), a left side (12C) and a right side (12C), with bristle tufts extending from the bristle surface (12). The bristle tufts comprise first tufts (14) comprising first bristles (141) having a rounded top end and second tufts (16) comprising second bristles (161) in conical shape, where some of the first tufts (14) are arranged in the outermost rounded nest (15) closest to the distal end (12A), and where the second tufts (16) are arranged on the left side (12C) and the right side (12D) of the bristle surface (12), where the first tufts (14) are arranged between the second tufts (16). A toothbrush including the toothbrush head is also provided. The toothbrush can well remove dental plaque in all dangerous areas.

Description

Technical Field

[0001] The present invention relates to a toothbrush, and more particularly to the bristle configuration of the toothbrush head. In particular, the present invention relates to an improved toothbrush bristle configuration including different types of bristle filaments arranged in a specific pattern. Background Art

[0002] Toothbrushes are well-known oral hygiene devices. They are used to clean teeth, remove residues between and on teeth, and remove dental plaque on the tooth surfaces. Dental plaque is one of the main causes of tooth decay and periodontal problems such as gingivitis and periodontal diseases such as periodontitis.

[0003] A toothbrush generally includes a toothbrush head and a handle. The toothbrush head is usually an oval, elliptical or rectangular plate from which bristle clusters extend. This bristle surface of the toothbrush head is known in the art as the bristle surface. The bristles are the cleaning part of the toothbrush. Many techniques for attaching the bristles or bristle clusters to the bristle surface are known depending on the materials of the bristles and the toothbrush head. For example, polymeric plastic filaments can be cut and U-shaped folded into double-headed bristles, bundled and tied in small metal anchors to form clusters. The anchors can be press-fitted into recesses, which are generally referred to as cluster holes, provided for the clusters on the bristle surface of the toothbrush head. The toothbrush head can be injection molded from a thermoplastic elastomer, where the cluster holes are foreseen on the bristle surface. The elasticity of the thermoplastic elastomer of the toothbrush head fixes the anchors, thereby fixing the bristle clusters to the bristle surface.

[0004] The toothbrush head is connected or connectable to the handle, which generally has an ergonomic gripping portion. The gripping portion is used to grasp and hold the toothbrush with one hand and guide the brushing movement of the toothbrush head in the mouth during brushing. In the prior art, the connecting portion between the handle and the toothbrush head is generally referred to as the neck or neck region. The neck can be equipped with a flexible region, as disclosed in WO12120014Al for example. When the user brushes with too much brushing force, the flexible device in the flexible region bends. This can prevent the teeth and gums from being subjected to excessive pressure.

[0005] Manual toothbrushes require manual movement. Electric toothbrushes perform automatic bristle movements, such as rotational oscillation or back-and-forth oscillation. There are also semi-electric toothbrushes, which are designed similar to manual toothbrushes but equipped with means for vibrating the toothbrush head.

[0006] Toothbrush bristles are filaments mainly made of polymeric plastic materials. Many different types of filaments for toothbrush bristles are known. Monofilament bristles are made of filaments of a single polymer material, usually polyamide (such as PA10.10 or nylon such as nylon 6.12), for example the bristle materials Medex or Tynex or polybutylene terephthalate (PBT). They usually have a uniform circular cross-section and are usually rounded at the ends, i.e., the ends away from the bristle surface are rounded to prevent damage to the oral soft tissues such as the gums. The filaments can have different cross-sectional diameters, resulting in soft (e.g., 0.15 mm diameter) to rigid (e.g., 0.38 mm diameter) bristles. Rigid monofilament bristles can achieve good cleaning of the exposed tooth surfaces. They are less flexible than soft bristles and can cause gum inflammation, damage, and bleeding. In addition, rigid monofilament bristles are too thick to penetrate into the interdental spaces between the teeth, and thus cannot remove the residues in the interdental spaces and the dental plaque on the mesial or distal tooth surfaces. Soft monofilament bristles are thinner and thus less rigid. This reduces the risk of gum damage. Soft monofilament bristles also penetrate better into the interdental spaces than rigid monofilament bristles. However, soft monofilament bristles are less durable due to flexing, bending, and wear. Brushing with a toothbrush having soft bristles also requires a longer brushing time to adequately clean and remove dental plaque because the soft bristles bend under the brushing pressure.

[0007] Tapered bristles are made of monofilament filaments with a tapered free end, i.e., the end away from the bristle surface that contacts the teeth during brushing. Tapered bristles can be made of filaments of polyamide (nylon such as nylon 6.12) or polyester such as polybutylene terephthalate (PBT). In the prior art, mechanically tapered bristles are used, where the ends of the filaments are mechanically ground to a point, and chemically tapered bristles, where the ends of the filaments are chemically etched to a point. PBT bristles are preferably chemically etched to a tapered end. Chemically tapered bristles are usually tapered to a finer point than mechanically tapered bristles. Tapered bristles have different bending and flexibility characteristics compared to non-tapered bristles. Tapered bristles have particularly good penetration in the interdental spaces. They can well remove the dental plaque on the mesial and distal tooth surfaces as well as the subgingival margins. Because they have fine ends, they are gentle on the gums, which is particularly preferred for people suffering from periodontitis and the like. However, due to their softness and limited brushing force, they require a longer brushing time to remove dental plaque. They are also prone to wear, for example due to bending, folding, and breaking.

[0008] Therefore, there is still a need for a toothbrush that can effectively and quickly clean teeth, especially the exposed surfaces of teeth, while also being able to penetrate well into the interdental spaces and subgingival margins, effectively remove dental plaque in these areas, and have a low risk of irritating the gums. A toothbrush that achieves this balance is particularly suitable for preventing periodontal problems such as gingivitis and periodontal diseases such as periodontitis. They are also particularly suitable for cases where such periodontal problems already exist, to prevent further deterioration and disease progression, and to support the recovery of the gums. Summary of the Invention

[0009] The present disclosure provides a toothbrush head that is connected to or connectable to a handle to define a head - handle longitudinal direction and a transverse direction perpendicular to the longitudinal direction. The head has a bristle surface that has a distal end away from the handle and a proximal end closer to the handle, a left side, and a right side. Bristle clusters extend from the bristle surface, where the bristle clusters include a first cluster and a second cluster. The first cluster includes first bristles having rounded tips, and the second cluster includes second bristles that are tapered. According to the invention, some of the first cluster are arranged in the outermost circular nests closest to the distal end, and the second cluster is arranged on the left and right sides of the bristle surface, where the first cluster is arranged between the second clusters.

[0010] In one embodiment, the second cluster consists only of the second bristles.

[0011] In one embodiment, the first cluster in the nests has a diagonal cut, where the length of the bristles increases towards the distal end of the bristle surface.

[0012] In one embodiment, there are 6 to 16 second clusters, preferably 8 to 12, and most preferably 10 second clusters.

[0013] In one embodiment, there are 15 to 23 second clusters.

[0014] In one embodiment, the second bristles have a length measured from where the second bristles protrude from the bristle surface, and this length is consistent for all second bristles.

[0015] In one embodiment, the length of the second bristles is longer than the length of any other bristles on the bristle surface.

[0016] In one embodiment, the length of the second bristles is greater than 12 mm, and the length of the first bristles is in the range of 9 mm to 11.5 mm.

[0017] In one embodiment, the first bristles are non - tapered, soft bristles with rounded ends and have a circular cross - section with a diameter of about 0.15 mm.

[0018] In one embodiment, the second bristles are chemically tapered PBT bristles and have a circular cross - section with a diameter of about 0.15 mm.

[0019] In one embodiment, there are only a first cluster and a second cluster on the bristle surface, some of the first cluster are arranged in a row that extends transversely and is closest to the proximal end, and some of the first cluster are arranged centrally inward from the second cluster on the bristle surface. Preferably, the transversely extending row consists of four first clusters. Preferably, the first clusters arranged centrally inward from the second cluster on the bristle surface include two longitudinal rows of at least three tufts of bristles.

[0020] A toothbrush is also provided that includes a toothbrush head as disclosed herein.

[0021] The bristle surface is preferably planar. The clustered bristles project from the bristle surface in the bristle direction. For all bristles, the bristle direction can be the same, or it can be different for different clusters. Preferably, for all bristles, the bristle direction is the same. It can be perpendicular to the bristle surface, or it can be inclined relative to the head-stem longitudinal direction or the transverse direction. Preferably, the bristle direction of the first cluster is perpendicular to the bristle surface. Preferably, the bristle direction of the second cluster is perpendicular to the bristle surface. Most preferably, the bristle directions of all the first and second clusters are perpendicular to the bristle surface. In embodiments having a planar bristle surface, most preferably all the first and second clusters extend from the bristle surface in a bristle direction perpendicular to the head-stem longitudinal direction and the transverse direction. In embodiments including other types of clusters in addition to the first and second clusters, preferably, all clusters extend from the bristle surface in a bristle direction perpendicular to the bristle surface.

[0022] Generally, there are 20 to 38 clusters on the toothbrush head. According to a preferred embodiment of the present invention, there are 29 clusters. In addition to the first and second clusters, there can be other types of clusters. However, preferably there are only the first and second clusters, and the first cluster is more than the second cluster.

[0023] The clusters can be fixed to the toothbrush head by methods known in the art. Preferably, the clusters are implanted into the toothbrush head using metal anchor technology. Small metal anchor pieces are used to bundle individual bristles into clusters. These metal anchor pieces are then inserted into the cluster holes on the bristle surface. The elasticity of the plastic material of the toothbrush head holds the metal anchor pieces in place. However, it should be emphasized that the specific and beneficial bristle arrangement disclosed herein is not limited to any clustering and / or implantation method. The bristle arrangement disclosed here can be achieved by any clustering and / or implantation method. For example, in another well-known process, the ends of the clusters can be supported and extended into a mold cavity in which the toothbrush head will be molded, and molten plastic material can be injected in a fluid state around these ends such that when the injected plastic material hardens, these ends are firmly embedded in the toothbrush head.

[0024] There may be 15 to 23 first clusters. Preferably, there may be 16 to 22 first clusters. Most preferably, 7 clusters form a circular nest at the proximal end of the bristle surface, and 10 to 12 additional first clusters. In an embodiment with a total of 29 clusters, preferably 7 first clusters form a circular nest, and 12 additional first clusters, i.e., a total of 19 first clusters. Some of the first clusters may be located directly on or near the axis along the longitudinal head-shank direction, or may be located on the left and right sides of the axis. Some of the first clusters may be arranged in rows that extend transversely closest to the proximal end of the bristle surface. Preferably, the first clusters are arranged axially symmetrically with respect to the axis along the longitudinal head-shank direction on the bristle surface. The first clusters have a generally circular cross-section, typically having a diameter of about 1.0 mm to about 2 mm. The first clusters include first bristles. The first clusters may additionally include other bristles. However, preferably, the first clusters are made entirely of first bristles. The first bristles are uniform end-rounded bristles. The first bristles may be made of polyamide filaments, such as nylon, e.g., nylon 6.12, or made of polybutylene terephthalate (PBT) or polyethylene terephthalate (PET). Preferably, the first bristles are made of polyamide filaments, i.e., PA10.10. Preferably, the polyamide material is made of a biomaterial, such as from the castor plant. The first bristles have a generally uniform circular cross-section, and are non-tapered and end-rounded, i.e., their ends away from the bristle surface are rounded to prevent damage to oral soft tissues such as the gums. The first bristles generally have a diameter of about 0.12 mm to about 0.18 mm. Most preferably, the diameter is about 0.15 mm. This strength provides good elasticity to the bristles and makes them suitable for sensitive gums. At the same time, they still ensure satisfactory cleaning and plaque removal.

[0025] Preferably, the first clusters in the circular nest at the distal end of the toothbrush tip have a diagonal cut, where the length of the bristles increases towards the distal end of the bristle surface. This diagonal cut improves the cleaning performance in hard-to-reach areas, such as molars or wisdom teeth.

[0026] According to a preferred embodiment of the present invention, there are 6 to 16 second clusters, preferably 8 to 12, and most preferably 10 second clusters (16). For example, five or six second clusters may be arranged in longitudinal rows on the outer left and right sides of the bristle surface, with the first clusters arranged between these two rows of second clusters. Preferably, the transversely extending row of first clusters is arranged at the proximal end of the toothbrush head.

[0027] According to a preferred embodiment, the length of the second bristles is greater than the length of any bristles on the bristle surface to ensure that they can enter the interdental spaces.

[0028] Preferably, the second bristles have a diameter of 0.15 mm at their main stem. Larger diameters have been tested, but it has been found that they produce an unpleasant sensation in the user's mouth without increasing the cleaning effect. The user reported a poking or itching sensation, which is thought to be due to the increased stiffness of the conical bristles with a larger diameter.

[0029] The toothbrush head of the present invention can be the head of a manual toothbrush, i.e., it contacts the user's teeth only by hand movement, or the head of an electric toothbrush, where the head is moved by an electric motor, such as a battery-driven motor, located in the handle. In the case of an electric toothbrush, the toothbrush head of the present invention can be permanently or replaceably connected to the toothbrush handle containing the drive motor in a manner well known in the toothbrush art, e.g., adapted to move the toothbrush head in a low-frequency motion under the action of the drive motor.

[0030] The toothbrush head can also optionally be equipped with a tongue cleaner. The tongue cleaner can be implemented on the surface of the toothbrush head opposite to the bristle surface and can be made of a thermoplastic elastomer by injection molding. Since the tongue cleaner can effectively remove bacteria on the tongue, it is particularly suitable for combination with the bristle arrangement of the present invention to provide a toothbrush that is particularly suitable for preventing and alleviating gum problems and periodontal diseases.

[0031] The toothbrush head can further optionally be equipped with an impact protection device. The impact protection device can cover a part of the outer surface of the toothbrush head and buffer any impact of the toothbrush head on the teeth and gums during rapid brushing. In addition, it generally gives the toothbrush head a soft and comfortable feel. It can be made of a thermoplastic elastomer by injection molding. Preferably, the impact protection device covers the side edges of the toothbrush head and, optionally, in embodiments without a tongue cleaner, also covers the surface opposite to the bristle surface. Thus, the risk of damaging the gums is further reduced, which makes the impact protection device particularly suitable for combination with the bristle device disclosed herein.

[0032] The present disclosure also provides a toothbrush that includes a toothbrush head as disclosed herein. The toothbrush can optionally include a handle device to reduce excessive brushing force. Examples of such devices are a ball joint or a flexible connection in the neck region. These devices buffer the excessive pressure that the user may exert on the teeth by bending, which further reduces the risk of excessive brushing force damaging the gums.

[0033] The present invention will now be described by way of example only with reference to the accompanying drawings. Description of the Drawings

[0034] Figure 1 A perspective view of a toothbrush according to the present invention is shown.

[0035] Figure 2 A perspective view of a toothbrush head according to the present invention is shown.

[0036] Figure 3 shows a Figure 2 side view of the toothbrush head.

[0037] Figure 4 shows a Figure 2 and 3 top view of the toothbrush head.

[0038] Figure 5A shows the automatic plaque area index on the buccal side.

[0039] Figure 5B shows the automatic plaque area index on the lingual side.

[0040] Figure 5C shows the automatic plaque area index on the mesial side.

[0041] Figure 5A shows the automatic plaque area index on the distal side. Detailed Description

[0042] Definition

[0043] The term "tapered bristle" or "tapered filament" is a term in the field of toothbrush bristles, and synonyms are "pointed bristle" or "needle bristle".

[0044] The term "soft bristle" or "soft filament" is a term known to those skilled in the art of developing, designing, and manufacturing toothbrushes.

[0045] Unless otherwise specified, the length of the bristle is measured from where the bristle extends from the bristle surface.

[0046] Detailed Description of the Drawings

[0047] Figure 1 shows a perspective view of a toothbrush including Figure 2 the toothbrush head 10 shown in more detail in. In Figure 1 the illustrated embodiment, the toothbrush head 10 is made of two materials, namely polypropylene and thermoplastic elastomer. In Figure 1 it is also shown that the toothbrush head 10 is molded integrally with the toothbrush handle 20. Between the head 10 and the handle 20, a neck with a ball joint 15 is formed. The ball joint 15 reduces the risk of damage to the teeth or gums caused by excessive brushing pressure. Away from the head 10, a flexible zone 22 is formed in the handle 20 in the region near the neck and the ball joint 25. The flexible zone 22 is also referred to as an S-shaped bend and bends when the user applies pressure, thus also reducing the risk of damage to the teeth or gums caused by excessive brushing pressure.

[0048] Figure 2 is shown in more detail Figure 1The toothbrush head. The toothbrush head 10 has a flat bristle surface 12 (as Figure 3 and Figure 4 shown), which has a trapezoidal profile with rounded edges and is approximately 26 mm long in the head - handle longitudinal direction (L - L). In the transverse direction (W - W), its proximal end is wider than the distal end, with a maximum width of approximately 13 mm. The head 10 includes a total of 29 bristle clusters 14, 16 that project from the bristle surface 12. The first cluster 14 consists of soft standard bristles 141 with rounded ends, while Figures 1 - 3 the second cluster 16 shown in

[0049] and having a tapered tip consists of tapered bristles 161. Figure 3 The side view in

[0050] shows that the bristles 141 of the nest 15 have a diagonal cut, where the bristles are longer at the distal end 12A of the nest 15 and shorter at the proximal end of the nest 15. The length l2 of the longest standard soft bristle 141 in the nest 15 is approximately 11 mm, and the length l1 of the shortest bristle 141 in the nest 15 is approximately 10 mm.

[0051] In addition, a total of seven clusters 14 consisting of standard soft bristles 141 are arranged in a circle at the distal end 12A of the bristle surface 12, also known as the nest 15.

[0052] The soft standard bristles 141 of the first cluster 14 are filaments based on a bio - sourced polyamide material, namely a polymer blend based on PA10.10 poly(decamethylene - decanediamide); may contain functional additives and ultimately a colorant. They can be purchased as Greenline filaments manufactured by Pedex GmbH / Perlon and have a diameter of 0.15 mm.

[0053] The tapered bristles 161 of the second cluster 16 are longer, which is already visible in Figure 1 and 2 and asFigure 3 as shown in the side view. The length 13 of these tapered bristles 161 is about 12.5 mm, so they extend beyond all standard soft bristles 141. The tapered bristles 161 are PBT tapered filaments, mainly composed of poly(butylene terephthalate), and can be purchased from BBC Co., Ltd. in Korea. Their diameter is also 0.15 mm.

[0054] Figure 4 A top view of the toothbrush head 10 and the bristle surface 12 is shown, and the bristle surface 12 has a flat surface. There are 29 depressions, also known as cluster holes, on the bristle surface 12, and the bristle clusters are implanted therein. The clusters are implanted using the metal anchor technology known in the toothbrush field. The diameter of the cluster holes is about 1.7 mm.

[0055] For the first cluster 14, each cluster contains 72 + / - 4 bristles 141 or filaments. For the second cluster 16, each cluster contains 80 + / - 10 bristles 161 or filaments.

[0056] Outside the nest 15 with diagonal side cuts, the lengths of all the bristles within the same cluster 14, 16 will always be the same.

[0057] Example

[0058] The manual toothbrush of the present invention includes the toothbrush head as described above and as Figures 1 to 4 shown, and it is evaluated according to the plaque removal efficacy. This test is a clinically validated brushing robot test, including human tooth models. The efficacy of plaque removal is evaluated using an automatic plaque plane evaluation that analyzes 30 regions of each tooth, as shown in FIGS. 5A to 5D.

[0059] FIG. 5A shows the APP index of the buccal side, i.e., towards the cheek, while FIG. 5B shows the APP index of the lingual side, i.e., towards the tongue. FIG. 5C shows the APP index of the mesial side, i.e., the proximal between the teeth in the front position, and FIG. 5D shows the APP index of the distal side, i.e., the proximal between the teeth in the rear position.

[0060] A human tooth model is stained with artificial dental plaque, subjected to a defined robotic brushing with horizontal, vertical, and rotational motions, and a brushing force of 3.5 N is applied in the anatomical position. The reduction of stain in 30 predefined areas of each tooth surface is evaluated by an automated optical method. Particular emphasis is placed on the "high-risk" areas of the tooth: the root surface or root area, the area immediately above the root surface and near the gum line, especially in the interproximal area, where dental plaque is difficult to remove and is most relevant to the prevention and alleviation of periodontal disease. The toothbrush according to the present invention is compared with two control toothbrushes. The first control toothbrush is a commercially available toothbrush (Curaprox CS1560), which has a flush cut and standard soft filaments with rounded ends, similar to the standard filaments 141 used in the first cluster 14 of the toothbrush according to the present invention. The second control toothbrush is a commercially available toothbrush (Meridol Sanft), which has only chemically asymptotic filaments similar to the tapered filaments 161 used in the second cluster 16 of the toothbrush according to the present invention. Brushing is performed at a brushing force of 3.5 N corresponding to medium brushing force. Three rounds of tests are conducted: horizontal, rotational, and vertical brushing motions, repeated 7 times each.

[0061] The results are shown in Table 1 below:

[0062]

[0063] ***p ≤ 0.001; **p < 0.01; *p < 0.05

[0064] The percentage of dental plaque reduction shown in Table 1 corresponds to the average of the buccal and lingual surfaces of EGHI and ABCDF, and the average of the mesial and distal surfaces of XY. The percentage of dental plaque reduction is the average of 7 runs for each motion.

[0065] Statistical analysis is performed by applying the Kolmogorov-Smirnov test (KS test, a one-sample test) to test 11 variables of the tooth surface - 'buccal', 'lingual','mesial', 'distal', 'buccal risk area ABCDF', 'lingual risk area ABCDF', 'W buccal', 'W lingual', 'W1 + W2 mesial', 'W1 + W2 distal', and 'total' - to obtain the normal distribution of the cleaning efficacy / plaque removal value, while comparing two toothbrushes each time.

[0066] The significance level a = 0.10 (10%) is used to test this important hypothesis for the calculation of the arithmetic mean and the parametric t-test. As a result, the null hypothesis of normality is clearly rejected, and all 11 cleaning parameters / tooth surfaces are not accepted.

[0067] As a result, all of the above parameters were analyzed by means of a non-parametric Wilcoxon-Mann-Whitney-U test (WMW-test or U-test) to evaluate whether the ranks and medians of the two test toothbrushes (the toothbrush according to the invention and the toothbrush of control 1 and the toothbrush according to the invention and the toothbrush of control 2) were statistically different.

[0068] For the two-tailed test of the difference in cleaning efficacy between the two toothbrushes (i.e., the toothbrush according to the invention and the toothbrush of control 1 and the toothbrush according to the invention and the toothbrush of control 2), the significance level was set at a basic p-value (*) of 0.05 (5%) significance. The significance values for a higher level of significant difference are specifically marked in Table 1: a p-value of 0.01 (1%) (very significant) (**) and a p-value of 0.001 (1‰) (highly significant) (***).

[0069] The experiments showed that for all three brushing movements, for the gingival margin risk areas (ABCDF) and the interdental risk areas (XY), the toothbrush according to the invention achieved a significantly higher total percentage of plaque removal than the two control toothbrushes. For vertical brushing of the smooth surfaces (EGHI), the toothbrush according to the invention also obtained better results and still had a high cleaning efficacy (comparable to the control toothbrushes) on the smooth surfaces for horizontal and rotational brushing.

[0070] Therefore, the toothbrush with the bristle configuration according to the invention is optimal for plaque control in all risk areas and helps to prevent dental caries and gingivitis.

[0071] List of reference signs

[0072] 10 Head

[0073] 12 Bristle surface

[0074] 12A Distal end of the bristle surface

[0075] 12B Proximal end of the bristle surface

[0076] 12C Left side of the bristle surface

[0077] 12D Right side of the bristle surface

[0078] 14 First cluster of the first bristles

[0079] 141 First bristle

[0080] 15 Nest

[0081] 16 Second cluster of the second bristles

[0082] 161 Second bristle

[0083] 20 Shank

[0084] 22 Flexible region (S-shaped bending part)

[0085] 25 Ball joint

[0086] W - Width direction

[0087] L - Length direction

[0088] 11 Minimum length of the first cluster

[0089] l2 Maximum length of the first cluster

[0090] 13 Length of the second cluster

Claims

1. A toothbrush head (10) which is connected or connectable to a handle (20) to define a head-handle longitudinal direction (L-L) and a transverse direction (W-W) perpendicular to the longitudinal direction (L-L), the head (10) having a bristle surface (12) which has a distal end (12A) remote from the handle (20), a proximal end (12B) closer to the handle (20), a left side (12C) and a right side (12C), wherein bristle clusters extend from the bristle surface (12), wherein the bristle clusters include a first cluster (14) containing first bristles (141) having rounded tips and a second cluster (16) containing second bristles (161) which are tapered, wherein, Some of the first clusters (14) are arranged in the outermost circular nests (15) closest to the distal end (12A), and among them, the second clusters (16) are arranged on the left side (12C) and the right side (12D) of the bristle surface (12), and the first clusters (14) are arranged between the second clusters (16).

2. The toothbrush head (10) according to claim 1, wherein, The second cluster (16) consists only of second bristles (161).

3. The toothbrush head (10) according to any one of the preceding claims, wherein, The first cluster (14) of the nest (15) has a diagonal cut, where the lengths (l1, l2) of the bristles increase towards the distal end (12A) of the bristle surface (12).

4. The toothbrush head (10) according to any one of the preceding claims, wherein, There are 6 to 16 second clusters (16), preferably 8 to 12, and most preferably 10 second clusters (16).

5. The toothbrush head (10) according to any one of the preceding claims, wherein, There are 15 to 23 first clusters (14).

6. The toothbrush head (1) according to any one of the preceding claims, wherein, The second bristle (8) has a length (l3) greater than the lengths (l1, l2) of any other bristle on the bristle surface (12).

7. The toothbrush head (1) according to any one of the preceding claims, wherein, The length of the second bristle (161) is greater than 12 mm, and the length of the first bristle (141) is in the range of 9 mm to 11.5 mm.

8. The toothbrush head (1) according to any one of the preceding claims, wherein, The first bristle (141) is a non-tapered, round-ended soft bristle with a circular cross-section having a diameter of about 0.15 mm.

9. The toothbrush head (1) according to any one of the preceding claims, wherein, The second bristle (161) is a tapered PBT bristle with a circular cross-section having a diameter of about 0.15 mm.

10. The toothbrush head (1) according to any one of the preceding claims, wherein, There are only the first clusters (14) and the second clusters (16) on the bristle surface (12), and among them, some of the first clusters (14) are arranged in rows that extend transversely closest to the proximal end (12B), and some of the first clusters (14) are arranged centrally inward from the second clusters (16) on the bristle surface (12).

11. The toothbrush head (1) according to claim 10, wherein, The row of the first clusters (14) that extends transversely closest to the proximal end (12B) consists of four first clusters (14).

12. The toothbrush head (1) according to claim 10 or 11, wherein, The first clusters (14) arranged centrally inward from the second clusters (16) on the bristle surface (12) include two longitudinal rows of at least three clusters (14).

13. The toothbrush head (1) according to claim 15, wherein, The first bristle (6) has a length measured from where the first bristle (6) protrudes from the bristle surface (3), and this length varies in a concave cut along the head-stem longitudinal direction (L-L), and the first bristles (6) located closest to the distal end (3A) and closest to the proximal end (3B) have the same length (l2).

14. A toothbrush comprising a toothbrush head (12) according to any one of the preceding claims, and further comprising a flexible zone (22), in particular an S-shaped bend, in the upper region of the handle.

15. The toothbrush according to the previous claim, further comprising a ball joint (25) in the neck region.

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