US20080201886A1

US20080201886A1 - Toothbrush Head

Info

Publication number: US20080201886A1
Application number: US12/067,516
Authority: US
Inventors: Uwe Bielfeldt; Alois Koppl; Ulrich Storkel; Michael Waldmeier
Original assignee: Braun GmbH
Current assignee: Braun GmbH
Priority date: 2005-09-22
Filing date: 2006-08-24
Publication date: 2008-08-28
Also published as: EP1926410A1; WO2007033745A1; DE102005045279A1; CN101272713A

Abstract

A toothbrush head with a bristle support member on which a bristle zone with a plurality of bristle tufts is arranged. The bristle tufts include three differently inclined groups of bristle tufts of which a first group is arranged essentially perpendicular to the plane of the bristle support member, a second group is inclined in a direction transverse to the toothbrush head longitudinal axis towards a first side, and a third group is inclined in a direction transverse to the toothbrush head longitudinal axis towards an opposite second side, with the inclined bristle tufts of the second and third group being arranged in transverse rows on the bristle support member. In each transverse row of inclined bristle tufts, all the bristle tufts are inclined towards the same side, with the bristle inclined from the outside inwards.

Description

TECHNICAL FIELD

This invention relates to a toothbrush head, more particularly to a toothbrush head with three differently inclined groups of bristle tufts.

BACKGROUND

Manual toothbrushes have, in their simplest version, bristle tufts which are oriented on the bristle support member to be perpendicular to the plane defined by the support member. There are many different modifications of this arrangement in existence. They include brush heads with tufts of various length, cf. U.S. Pat. No. 6,276,021 or U.S. Pat. No. 5,305,489, brush heads with tufts with variously long bristles, cf. WO 98/07348, brush heads with bristle tufts inclined in the direction of the toothbrush longitudinal axis, cf. U.S. Pat. No. 6,272,714, and toothbrush heads with bristle tufts inclined in a direction transverse to the toothbrush longitudinal axis. The latter arrangement, disclosed in U.S. Pat. No. 5,335,389, has a plurality of bristle tufts arranged in transverse rows one behind the other on the bristle support member. In this arrangement, transverse rows with non-inclined bristle tufts alternate with transverse rows which have inclined bristle tufts. As such, the outermost bristle tufts in a transverse row are inclined outwards so that they are splayed apart in V-shape. The outer, outwardly inclined bristle tufts are intended to clean simultaneously the gingival space at the gingival margin of the upper jaw and at the gingival margin of the lower jaw.
A similar arrangement of bristle zones with outwardly inclined bristle tufts at the outer edge of the bristle zone is disclosed in U.S. Pat. No. 5,628,082, U.S. Pat. No. 3,722,020, U.S. Pat. No. 4,010,509 or WO 2004/037038 A1. The latter document discloses, in addition to the transverse rows of bristle tufts with outwardly inclined bristle tufts, a transverse row with two inwardly inclined bristle tufts. With the aid of these counter-inclined bristle tufts it should be possible to achieve in particular an improved cleaning of the concave biting surface of the molars. However, such counter-inclined bristle tufts are less suited for cleansing in the interproximal area and in the gingival area of the teeth. The ends of the counter-inclined bristle tufts are no longer able to move freely in their predetermined incline and are obstructed by the other bristle tufts with the opposite incline.
A bristle zone with inwardly inclined bristle tufts is also disclosed in WO 01/89344 A2, in which the bristle tufts are inclined not only in a direction transverse to the toothbrush longitudinal axis but also in the direction of the toothbrush longitudinal axis. With this configuration, the bristle tufts of a transverse row are inclined in different transverse and longitudinal directions so that the bristle tufts partly overlap when looking in both the toothbrush longitudinal direction and the toothbrush transverse direction. Here too the result is an obstruction of the inclined bristle tufts by bristle tufts with a different inclination. With this toothbrush, the cleaning of the planar portions of the teeth is capable of improvement in addition.
Furthermore, CH 324623 discloses a toothbrush with transverse rows of bristle tufts each inclined in one direction. This toothbrush sets out to do completely without perpendicular bristle tufts in order not to grind any flutes in the dental enamel and in order to prevent wedge-shaped defects there in the long term. With this prior known bristle configuration it is possible to achieve a satisfactory cleansing of the interproximal spaces, but the cleansing of the planar areas of the teeth is poor.

SUMMARY

In one aspect, a toothbrush head includes a bristle support member on which a bristle zone with a plurality of bristle tufts is arranged. Three groups of bristle tufts are arranged on the bristle zone and inclined in special manner. The bristle tufts of the second and third group, which are provided in addition to the perpendicularly arranged bristle tufts of the first group, are inclined from the outside inwards, whereby in each transverse row of inclined bristle tufts all the bristle tufts of a transverse row are inclined towards the same side. The term from the outside inwards as used herein means an arrangement in which, when a transverse row is considered in its entirety, the bristle tuft base lying on the bristle support member lies closer to the outer edge of the bristle zone than the bristle tuft head which, when a transverse row is considered in its entirety, lies more in the center of the bristle zone. If a bristle tuft lies with its tuft base on the left-hand side of the bristle support member, then it is inclined from the outside inwards when its free end is inclined towards the right-hand side of the bristle support member.
Through the triple oriented groups of bristle tufts it is possible, without special tilting of the toothbrush head, to cleanse both the planar portions of the teeth as well as the interproximal and gingival areas of the teeth equally effectively. The perpendicularly upstanding bristle tufts of the first group ensure a thorough cleansing of the planar portions of the teeth. By contrast, the inclined bristle tufts of the second and third group clean the interproximal and gingival areas of the teeth. The special arrangement of the inclined bristle tufts, namely the inclination of all the bristle tufts in the same transverse row to the same side, namely from the outside inwards, has the effect that all the ends of the bristle tufts of the second group, which are inclined for example from left to right, point in the direction of the gingival margin and clean there when the toothbrush is engaged against a jaw half. At the same time, all the ends of the bristle tufts of the third group, which then are inclined in reverse from right to left, then point in the direction of the occlusal surfaces of the teeth, enabling them to penetrate into the interproximal area of the teeth. Using a simple cleaning movement parallel to the row of teeth, this results in a simultaneous cleaning of different areas, namely the middle planar portions of the teeth, the gingival area and the interproximal area of the teeth, without the toothbrush needing to be specially tilted. The toothbrush head described herein, when placed untilted on a jaw half, unites in this case the technique referred to as the Bass technique, with which the toothbrush is placed such that the bristle ends are inclined towards the gingival area of the teeth, and the technique referred to as the Charters technique, with which the toothbrush is placed such that the bristle tufts are oriented away from the gingival margin towards the occlusal area of the teeth. If the toothbrush head is engaged parallel to the row of teeth against the facial or lingual tooth surfaces, then the bristle ends of the inclined bristle tufts align themselves along the tooth axis. The bristle tufts of the one direction of inclination move towards the gingival margin while the bristle tufts oriented in the opposite direction move towards the masticatory surfaces. Because of the dimensions and arrangement of the tufts, the bristle ends of the bristle tufts of one direction of inclination end in the area of the gingival margin while the bristle ends of the bristle tufts inclined in the other direction reach, when placed in position, into the interproximal area in particular because as the result of the proposed arrangement they are not obstructed by any other bristle tufts. The bristles of the perpendicularly upstanding bristle tufts end on the facial or lingual surfaces. In consequence, the toothbrush must no longer be moved successively into different defined positions in order to clean the different areas of the teeth. An effective cleaning of the different areas takes place concurrently even during a simple movement along the row of teeth referred to as the horizontal scrubbing technique.
In this arrangement, the bristle tufts of the inclined transverse rows may be inclined solely in a direction transverse to the toothbrush longitudinal axis so that they extend in a plane perpendicular to the toothbrush longitudinal axis. In this way the above described effect of cleaning the interproximal area and gingival area of the teeth can be achieved in excellent manner.
In some implementations, the bristle tufts of the second and/or third group may also have, in addition to their inclination transverse to the toothbrush longitudinal axis, an inclination component in the direction of the toothbrush longitudinal axis. Through a slight inclination also in the direction of the toothbrush longitudinal axis it is possible to improve the penetration of the correspondingly inclined bristle tufts into the interproximal spaces in particular during horizontal scrubbing. With this configuration, forwardly inclined tufts penetrate into the interproximal spaces when the brush is pushed forward. Backwardly inclined tufts penetrate into the interproximal spaces when the brush is pulled backward.
There is no need in general for the bristle tufts arranged in a transverse row to have the same inclination. For example, bristle tufts which are anchored farther to the outside on the bristle support member could exhibit a stronger inward inclination than bristle tufts which are arranged farther inside on the bristle support member. However, in some implementations, all the bristle tufts arranged in a common transverse row are of like inclination. This promotes a uniform cleaning effect of a respective transverse row of inclined bristle tufts.
Provided they are arranged respectively in a common transverse row, then in particular the bristle tufts of the second and third group are arranged in a common plane which otherwise has no differently inclined bristles or perpendicularly upstanding bristles. The bristle tufts arranged in a common plane are all inclined to the same side and are not obstructed by differently inclined or perpendicularly upstanding bristle tufts. In this way a collision between differently inclined bristle tufts is ruled out. Penetration into the interproximal area of the teeth on the one hand and cleaning of the gingival area of the teeth on the other are thus rendered still more efficient.
In principle it would be conceivable for the bristle ends of the different groups of bristle tufts to lie in a common plane. However, in some implementations, the bristle tufts of the second and/or third group are constructed to be higher than the bristle tufts of the first group. In this way the inclined bristle tufts are better able to penetrate into the interproximal or subgingival area, while at the same time the perpendicularly upstanding bristle tufts stand upright on the planar surfaces of the teeth for cleaning this particular area.
In this configuration, it would be conceivable in principle for the bristles within the same group of bristle tufts to end in a common plane. Preferably, however, the bristles of the different bristle tufts of the second group as well as the bristle tufts of the third group end at different levels. In particular the bristle tufts in a common transverse row are constructed to be different in height. As such, preferably the inclined bristle tufts, whose head lies approximately in the center of the bristle zone, are constructed to be higher than the inclined bristle tufts of the same transverse row which are arranged with their head farther outside towards the edge of the bristle zone. In this way there results, looking in the longitudinal direction of the toothbrush head, an approximately roof-shaped envelope contour which is defined by the ends of the inclined bristle tufts.
Preferably, the heads of the inclined bristle tufts in a common transverse row form an approximately rectilinear contour downwardly sloping towards the outer side of the bristle zone. Said rectilinear contours, which are described by the heads of the inclined bristle tufts, are downwardly sloping in counter-inclined transverse rows towards opposite sides so that on the whole the previously mentioned approximately roof-shaped contour results in the toothbrush longitudinal direction looking at the bristle zone.
Advantageously, the counter-inclined bristle tufts of the second group and the third group are arranged such that, looking in the toothbrush longitudinal direction, the bristle tufts of the second group overlap at least partly the bristle tufts of the third group and vice versa. Advantageously, the arrangement is chosen such that each bristle tuft of the second group, looking in the toothbrush longitudinal direction, overlaps at least one bristle tuft of the third group and vice versa.
In some implementations, the bristle zone has in its head or working area a greater bristle tuft density than in the foot zone on the bristle support member. The base area of the bristle zone, which is defined by the bristle tuft feet on the bristle support member, is at least as large as the working area of the bristle zone defined by the bristle tuft heads. Owing to the inclination of the bristle tufts of the second and third group from the outside inwards, an expansion of the bristle zone with the height of the bristles increasing is prevented from occurring.
In some embodiments, the bristle zone encompasses at least three transverse rows of bristle tufts of the second group as well as at least three transverse rows of bristle tufts of the third group. Preferably, in this configuration the transverse rows of the bristle tufts of the second group and the transverse rows of the bristle tufts of the third group are arranged alternately one behind the other in the toothbrush longitudinal direction. The perpendicularly arranged bristle tufts of the first group are arranged advantageously between the transverse rows of the second and third group.
In particular a pair of transverse rows of bristle tufts of the second group and bristle tufts of the third group are followed in the toothbrush longitudinal direction by bristle tufts of the first group before there again follows a pair of transverse rows of bristle tufts of the second and third group.
By arranging the inclined bristle tufts of the second and third group in planes perpendicular to the toothbrush head longitudinal axis, the bristle tufts of the first group may be arranged likewise in transverse rows perpendicular to the toothbrush longitudinal axis. However, if the bristle tufts of the second and third group are biaxial, i.e., arranged both transverse to the toothbrush longitudinal axis and parallel thereto, inclined and/or arranged in planes which are inclined at an acute angle to the toothbrush longitudinal axis, then the bristle tufts of the first group may be combined to form triangular bristle zone sections between respective transverse rows of inclined bristle tufts.
The bristle tufts of the three groups generally may have the same cross-section, with different cross-sectional shapes being possible. For example, the bristle tufts may have a round, an angular or an elongated cross-section. In some cases, provision may be made for the perpendicularly upstanding bristle tufts of the first group to have a cross-section which differs from the cross-section of the bristle tufts of the second and third group. In particular the bristle tufts of the first group may have an essentially approximately circular cross-section. By contrast, in certain cases, the bristle tufts of the second and third group may have an approximately rectangular cross-section, with the cross-section extending with its longitudinal sides parallel to the outer contour of the respective transverse row in which the respective bristle tuft is arranged.
The degree of inclination of the bristle tufts of the second and third group may generally be selected to differ. According to a preferred embodiment, the bristle tufts of the second and third group are inclined relative to a perpendicular on the bristle support plane at an angle of 5° to 45°, preferably 15° to 30°, approximately. In particular the bristle tufts may be inclined relative to the perpendicular on the bristle support plane at an angle of 20° to 25°, approximately.
These and further features which, in combination and sub-combination, may form the subject matter of the present description will become apparent not only from the claims but also from the subsequent description and the associated drawing with reference to which preferred embodiments are be explained.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a toothbrush head of a manual toothbrush having a bristle zone;

FIG. 2 is a perspective view of a toothbrush head of a manual toothbrush;

FIG. 3 is an end view of the toothbrush head of FIG. 2;

FIG. 4 is a side view of toothbrush head of FIGS. 2 and 3; and

FIG. 5 is a top plan view of the bristle zone of the toothbrush head of the preceding FIGS. 2 to 4.

DETAILED DESCRIPTION

The toothbrush heads 1 illustrated in the drawings have an approximately plate-shaped bristle support member 2 to which a plurality of bristle tufts are attached, which combine to form a bristle zone 3. The bristle tufts may be attached to the bristle support member 2 in a variety of ways. For example, they may be anchored on the bristle support member 2 by an anchor tufting method or they may be integrally molded in the bristle support member 2 by an injection molding method or be fastened to the bristle support member 2 by a welding method.
The bristle tufts are divided into three different groups of bristle tufts. A first group of bristle tufts 4 is arranged essentially perpendicular to the plane defined by the plate-shaped bristle support member 2. A second group of bristle tufts 5 is inclined in a direction transverse to the toothbrush head longitudinal axis 7 towards a first side of the toothbrush head, while the third group of bristle tufts 6 is equally inclined in a direction transverse to the toothbrush head longitudinal axis 7 but towards the opposite side of the toothbrush head.
In the embodiment of the toothbrush head 1 shown in FIG. 1, the bristle tufts are arranged in transverse rows on the bristle support member 2. As FIG. 1 shows, the perpendicularly arranged bristle tufts 4 of the first group are arranged in altogether five transverse rows on the bristle support member 2, each transverse row accommodating between two and four bristle tufts 4. Arranged between the respective transverse rows of the bristle tufts 4 of the first group is one transverse row of bristle tufts of the second group and one transverse row of bristle tufts 6 of the third group so that on the whole transverse rows of bristle tufts from the first group, the second group and the third group alternate with each other.
The bristle tufts 5 of the second group, which are arranged in a common transverse row, lie in a common plane which extends essentially perpendicular to the longitudinal axis 7 of the toothbrush head 1. In this arrangement, all the bristle tufts 5 of the second group have the same angle of inclination towards the same side. Similarly, the bristle tufts 6 of the third group, which are arranged in a common transverse row, have the same angle of inclination towards the opposite side, being arranged in a common plane. The angle of inclination 8 of the bristle tufts 5 of the second group amounts preferably to approximately 85 to 55° relative to the plane defined by the bristle support member 2 (cf FIG. 1). The angle of inclination of the bristle tufts 6 of the third group is equally large but oriented towards the opposite side of the toothbrush head 1.
In the embodiment shown in FIGS. 2 to 5, the inclined bristle tufts 5 of the second group and the inclined bristle tufts 6 of the third group are likewise combined in transverse rows.
In the embodiment of FIGS. 2 to 5, the bristle tufts 5 of the second group as well as the bristle tufts 6 of the third group have an inclination both transverse to the toothbrush longitudinal axis 7 and parallel thereto. As shown in particular in FIG. 5, the bristle tufts 5 and 6 are arranged in transverse rows which do not extend at right angles in a direction transverse to the longitudinal axis 7 but slightly obliquely in a direction transverse to the longitudinal axis 7. In the embodiment shown (cf. FIG. 5), the transverse rows adopt an angle of 40° to 60°, approximately, relative to the longitudinal axis 7. The bristle tufts 5 and 6, which are attached to the bristle support member 2 in one transverse row each, are oriented such that they extend in a common plane and have the same inclination in said plane, as shown in FIG. 3. It will be understood, of course, that here too the bristle tufts 5 of the second group are inclined towards the one side of the bristle support member 2 while the bristle tufts 6 of the third group are inclined towards the other side of the bristle support member 2. In the embodiment shown, provision is made for respectively two bristle tufts 5 of the second group and two bristle tufts 6 of the third group per transverse row. The angle of inclination of said bristle tufts 5 and 6 of the second and third group, respectively, relative to the perpendicular 9 on the bristle support plane amounts in the embodiment shown to 20°, approximately. As FIG. 3 shows, the bristle tufts 5 and 6 of the second and third group are inclined from the outside inwards also in the embodiment of FIGS. 2 to 5. The base of the bristle tufts 5 and 6 attached to the bristle support member 2 is offset—when looking at a transverse row in its entirety—to a side edge of the bristle zone 3, with the respective bristle tufts 5 and 6 then extending with their tips to the other side of the bristle zone 3 and hence inwards.
As FIG. 3 shows, the inclined bristle tufts 5 and 6 do not all have the same length or height. The arrangement is chosen such that the bristle tufts 5 a and 6 a lying with their head in the center of the bristle zone 3 have a greater height than the bristle tufts 5 b and 6 b lying with their head farther to the outside. In this configuration, the free ends of the bristle tufts 5 and 6 are coordinated with each other in height such that the bristle tufts 5 and 6 arranged in the same transverse row define with their heads a rectilinear contour which slopes downwards to the outer side of the bristle zone 3 (cf. FIG. 3). As such, the ends of the bristle tufts 5 and 6 tilted to different sides define contours downwardly sloping to opposite sides so that an gable-roof-shaped envelope contour is defined by the ends of the inclined bristle tufts 5 and 6 (cf. FIG. 3).
As FIGS. 2 and 4 show, in this second embodiment the inclined bristle tufts 5 and 6 are again not obstructed from bending to and fro in their plane of inclination by other bristle tufts that are arranged perpendicular or are otherwise inclined. In each transverse row of tilted bristle tufts 5 or 6 there are only bristle tufts of the same inclination. In the planes that are defined by the bristle tufts of a transverse row, the bristle zone 3 is constructed devoid of other bristles.
Arranged between the transverse rows of inclined bristle tufts 5 and 6 are the bristle tufts 4 of the first group which are perpendicular to the plane of the bristle support member 2. As FIGS. 2 and 5 show, the bristle tufts 4 of the first group are arranged in triangular bristle tuft zones between the rows of the inclined bristle tufts 5 and 6 so that after a zone of bristle tufts 4 of the first group there follows, looking in the longitudinal direction of the toothbrush head 1, one transverse row of bristle tufts 5 of the second group and then one transverse row of bristle tufts 6 of the third group, this sequence being repeated several times to the extent that several transverse rows of inclined bristle tufts 5 and 6 are provided (cf. FIG. 5).
With this configuration, the bristle tufts 4 of the first group are constructed shorter than the bristle tufts 5 and 6 of the second and third group. The bristle tufts 5 and 6 of the second and third group have a greater height in order, as the result of their projection above the perpendicularly upstanding bristle tufts 4, to be better able to penetrate into the interproximal area and into the subgingival area of the teeth. In the embodiment shown in FIG. 3, the projecting inclined bristle tufts 5 and 6 in the center of the bristle zone 3 have a height which is greater by 20% to 30%, approximately, than the height of the perpendicular bristle tufts 4 of the first group.
As FIGS. 3 and 5 show, the outer contour, in particular the widest points of the bristle zone 3, are defined by the perpendicularly upstanding bristle tufts 4 of the first group. The inclined bristle tufts 5 and 6 of the second and third group extend within the circumference of the bristle zone 3, which is defined by the perpendicular bristle tufts 4.
The bristle tufts 4 of the first group have in addition a cross-section which differs from the cross-section of the inclined bristle tufts 5 and 6. While the perpendicularly upstanding bristle tufts 4 have an approximately circular cross-section (cf FIG. 2), the inclined bristle tufts 5 and 6 have a slim rectangular cross-section (cf. FIGS. 4 and 5), with the longitudinal sides of this rectangular cross-section extending parallel to the respective plane in which the bristle tufts 5 and 6 in the same transverse row are arranged.

Claims

1-17. (canceled)

18. A toothbrush head, comprising:

(i) a bristle support member defining a plane and containing a longitudinal axis of the toothbrush head;

(ii) a bristle zone on the bristle support member;

(iii) a plurality of bristle tufts arranged in the bristle zone, the plurality comprising:

(a) a first group of bristle tufts arranged substantially perpendicular to the plane of the bristle support member;

(b) a second group of bristle tufts arranged in transverse rows on the bristle support member, such that all of said bristle tufts are inclined from the outside inwards in a direction transverse to the longitudinal axis of the toothbrush head towards a first side of the toothbrush head; and

(c) a third group of bristle tufts arranged in transverse rows on the bristle support member, such that all of said bristle tufts are inclined from the outside inwards in a direction transverse to the longitudinal axis of the toothbrush head towards an opposite second side of the toothbrush head.

19. The toothbrush head of claim 18, wherein the bristle tufts in each transverse row of bristle tufts are arranged in a common plane in which the bristle zone is free from perpendicular and counter-inclined bristle tufts.

20. The toothbrush head of claim 18, wherein the bristle tufts in each transverse row of bristle tufts have the same degree of inclination.

21. The toothbrush head of claim 18, wherein the bristle tufts in each transverse row are inclined along the longitudinal axis of the toothbrush head.

22. The toothbrush head of claim 18, wherein the height of the bristle tufts of at least the second group or the third group exceeds the height of the bristle tufts of the first group.

23. The toothbrush head of claim 18, wherein the bristle tufts in any one transverse row are different in height.

24. The toothbrush head of claim 18, wherein, for any one transverse row, the height of the inclined bristle tufts with bristle heads near a center of the bristle zone exceeds the height of the inclined bristle tufts with bristle heads near an outer side of the bristle zone.

25. The toothbrush head of claim 18, wherein the heads of the inclined bristle tufts in any one transverse row form an approximately rectilinear contour downwardly sloping towards an outer side of the bristle zone.

26. The toothbrush head of claim 18, wherein the heads of the inclined bristle tufts of the second and third group define an approximately gable-roof-shaped contour with a longitudinal axis substantially parallel to the longitudinal axis of the toothbrush head.

27. The toothbrush head of claim 18, wherein the bristle tufts of the second group are inclined from the second side to the first side of the toothbrush head and the bristle tufts of the third group are inclined from the first side to the second side of the toothbrush head, such that bristle tufts of the second group and ,bristle tufts of the first group overlap at least in part along the longitudinal axis of the toothbrush head.

28. The toothbrush head of claim 18, wherein a base area of the bristle zone is at least as large as a corresponding working area of the bristle zone.

29. The toothbrush head of claim 18, wherein the transverse rows of the second group alternate with the transverse rows of the third group along the direction of the longitudinal axis of the toothbrush head.

30. The toothbrush head of claim 18, wherein bristle tufts of the first group are arranged between the transverse rows of the second group and the transverse rows of the third group.

31. The toothbrush head of claim 30, wherein bristle tufts of the first, second, and third groups are alternately arranged along the direction of the longitudinal axis of the toothbrush head.

32. The toothbrush head of claim 18, wherein the bristle tufts of the first group have a cross-section that differs from the cross-section of the bristle tufts of at least the second or third group.

33. The toothbrush head of claim 18, wherein all the bristle tufts of the first group have substantially the same cross-sectional shape.

34. The toothbrush head of claim 33, wherein the cross-sectional shape is approximately circular.

35. The toothbrush head of claims 18, wherein all the bristle tufts of the second and third groups have substantially the same cross-sectional shape.

36. The toothbrush head of claim 35, wherein the cross-sectional shape is approximately rectangular, and wherein the longitudinal sides of the rectangle extend substantially parallel to the longitudinal direction of the transverse row in which the bristle tufts are arranged.

37. The toothbrush head of claim 18, wherein the bristle tufts in the second and third groups are inclined relative to a perpendicular on the bristle support plane at an angle of about 5° to about 45°.

38. The toothbrush head of claim 37, the bristle tufts in the second and third groups are inclined relative to the perpendicular on the bristle support plane at an angle of about 10° to about 30°.

39. The toothbrush head of claim 38, the bristle tufts in the second and third groups are inclined relative to the perpendicular on the bristle support plane at an angle of about 15° to about 25°.