Abstract
This disclosure provides a toothbrush head and a toothbrush with improved toothbrush bristle configuration comprising different types of bristle filaments in a specified arrangement. Disclosed are toothbrush heads comprising first tufts (5) comprising first bristles (6) and second tufts (7) comprising second bristles (8), wherein the second tufts (7) are positioned outermost closest to the distal end (3A) and outermost closest to the proximal end (3B) on the bristle surface (3), and/or outermost closest to the widthways opposite ends (3C, 3D) on the bristle surface (3), and wherein the second bristles (8) have a stem (19) that splits into split ends (21), and wherein the split ends (21) are chemically tapered. Also provided are toothbrushes comprising said toothbrush heads. The toothbrushes achieve excellent brushing performance, plaque removal from the gingival and subgingival margin and reach into the interproximal spaces. There are also disclosed methods of manufacturing these toothbrushes.
Claims
1. A toothbrush head (1) connected to or connectable to a handle (2) to define a head-handle longitudinal direction (L-L) and a widthways direction (W-W) perpendicular to the longitudinal direction (L-L), the head (1) having a bristle surface (3) with a distal end (3A) further from the handle (2) and a proximal end (3B) closer to the handle (2), and having widthways opposite ends (3C, 3D), wherein tufts of bristles extend from the bristle surface (3), wherein the tufts of bristles comprise first tufts (5) comprising first bristles (6) and second tufts (7) comprising second bristles (8), wherein the first bristles (6) are non-tapered, end-rounded bristles with a circular cross-section, and wherein the second tufts (7) are positioned outermost closest to the distal end (3A) and outermost closest to the proximal end (3B) on the bristle surface (3), and/or outermost closest to the widthways opposite ends (3C, 3D) on the bristle surface (3), and wherein the second bristles (8) have a stem (19) that splits into split ends (21), and wherein the split ends (21) are chemically tapered.
2. A toothbrush head (1) according to claim 1, wherein the second tufts (7) consist solely of second bristles (8).
3. A toothbrush head (1) according to claim 1, wherein the second tufts (7) are positioned outermost closest to the widthways opposite ends (3C, 3D) on the bristle surface (3).
4. A toothbrush head (1) according to claim 3, wherein the second tufts (7) are positioned axisymmetric to the head-handle longitudinal direction (L-L) on the bristle surface (3).
5. A toothbrush head (1) according to claim 1, wherein the second bristles (8) have a length (l.sub.1), measured from where the second bristles (8) protrude from the bristle surface (3), which is uniform for all second bristles (8).
6. A toothbrush head (1) according to claim 5, wherein the length (l.sub.1) of the second bristles (8) is longer than the lengths (12, 13) of any other bristles on the bristle surface (3).
7. A toothbrush head (1) according to claim 1, wherein the stem (19) of the second bristles (8) extends over about 70% to about 80% of the length (l.sub.1) of the second bristles (8), measured from where the second bristles (8) protrude from the bristle surface (3).
8. A toothbrush head (1) according to claim 1, wherein the second bristles are about 1.5 mm to about 2.5 mm longer than the longest first bristles, measured from where the first and second bristles protrude from the bristle surface, and the split ends are about 2.5 mm to about 3.5 mm long, wherein a length of the split ends is measured from a point where the stem of the first bristles splits into the split ends to an end of the split ends.
9. A toothbrush head (1) according to claim 1, wherein the stem (19) of the second bristles (8) splits into 2 to 20 split ends (21).
10. A toothbrush head (1) according to claim 9, wherein the stem (19) of the second bristles (8) splits into two to eight split ends (21).
11. A toothbrush head (1) according to claim 1, wherein the stem (19) of the second filaments (8) has a circular cross-section with a diameter of 5 mil to 8 mil.
12. A toothbrush head (1) according to claim 1, wherein the first bristles (6) have a diameter of 5 mil to 8 mil.
13. A toothbrush head (1) according to claim 1, wherein there are only first tufts (5) and second tufts (7) on the bristle surface (3), and wherein the first tufts (5) are positioned outermost closest to the distal end (3A) and outermost closest to the proximal end (3B) and centrally, inwardly from the widthways opposite ends (3C, 3D), on the bristle surface (3).
14. A toothbrush head (1) according to claim 13, wherein the first bristles (6) have a length, measured from where the first bristles (6) protrude from the bristle surface (3), which varies in a concave cut along the head-handle longitudinal direction (L-L) and wherein the first bristles (6) positioned closest to the distal end (3A) and closest to the proximal end (3B) have the same length (l.sub.2).
15. A toothbrush head (1) A toothbrush comprising a toothbrush head (1) according to claim 1.
16. A method of treatment of gingivitis, comprising brushing teeth with a toothbrush according to claim 15.
17. A method of treatment of periodontal disease, for example periodontitis, comprising brushing teeth with a toothbrush according to claim 16.
18. A method of reducing plaque on interproximal surfaces of a tooth and surfaces of a tooth that are close to a gumline, comprising brushing teeth with a toothbrush according to claim 15.
19. A method of manufacturing a toothbrush, comprising the following steps in the following order: a) Providing first tufts comprising first bristles, wherein the first bristles are unitary bristles; b) Providing second tufts comprising second bristles, wherein the second bristles comprise chemically tapered split ends; c) Fixing the first tufts on a toothbrush head outermost closest to a distal end and outermost closest to a proximal end and centrally, inwardly from widthways opposite ends, on a bristle surface of the toothbrush head; d) Cutting the first tufts into a concave cut along a head-handle longitudinal direction of the toothbrush head; e) Polishing the bristles of the first tufts to provide unitary, end-rounded first bristles; f) Fixing the second tufts on the toothbrush head outermost closest to the widthways opposite ends on the bristle surface, wherein the second bristles, after fixing of the second tufts on the toothbrush head, have a length (l.sub.1), measured from where the second bristles protrude from the bristle surface, which is longer than a length of any of the bristles of the first tufts.
Description
DESCRIPTION OF DRAWINGS/FIGURES
[0074] FIG. 1 shows a top plane view of a toothbrush head of the present disclosure.
[0075] FIG. 2 shows a vertical cut view of the toothbrush head of FIG. 1, the cut being along the head-handle longitudinal direction.
[0076] FIG. 3 shows a side view of a toothbrush comprising the toothbrush head of FIG. 1.
[0077] FIG. 4 shows an elevated angled top view of the toothbrush head of FIG. 1 and a neck.
[0078] FIG. 5 shows a first bristle extending from a bristle surface.
[0079] FIG. 6 shows a second bristle extending from a bristle surface.
DETAILED DESCRIPTION OF THE DRAWINGS
[0080] FIG. 1 shows a top plane view of a toothbrush head (1) of the present disclosure. The toothbrush head (1) is a plate with an ovoid outline and is approximately 23 mm long in a head-handle longitudinal direction (L-L) and approximately 10 mm wide in a widthways direction (W-W). Along the head-handle longitudinal direction (L-L), starting from the left in FIG. 1, the toothbrush head (1) has a blunt, rounded end, then expands in the ovoid shape and finally ends in an again rounded end that merges seamlessly into a toothbrush neck. Both parts, i.e. head and neck, are manufactured in one moulding process from polypropylene. The neck can itself merge seamlessly into a handle (2) (as can be seen in FIG. 3), which is also from polypropylene. The toothbrush head (1) has a top surface, also referred to as bristle surface (3), and a bottom surface on the side opposite to the bristle surface (3) (the bottom surface is not shown in the figures). The bristle surface (3) is an even and horizontal surface. On the bristle surface (3) there are 33 depressions, also referred to as tuft holes, into which tufts of bristles are implanted. The tufts are implanted with the metal anchor technique, known in the art of toothbrushes. The tuft holes have a diameter of about 1.7 mm. The bristle surface (3) has: a distal end (3A) further from the handle and near the rounded end of the toothbrush head along the head-handle longitudinal direction (L-L); a proximal end (3B) closer to the handle (2) and on the end of the toothbrush head (1) opposite the proximal end (3A) along the head-handle longitudinal direction (L-L), and closest to the toothbrush neck; widthways opposite ends (3C, 3D), wherein a right side (3C) is along the right edge of the bristle surface, seen from above, and a left side (3D) is along the left edge of the brush surface, seen from above. The toothbrush head (1) comprises two different types of tufts: First tufts (5) and second tufts (7). The first tufts (5) are made from first bristles (6). The first bristles (6) are end-rounded unitary bristles. In FIG. 1, the first tufts (5) are depicted by unfilled circles. The first bristles (6) are made from nylon filaments with a diameter of about 6 mil. The first tufts (5) have a diameter of about 1.7 mm, as they fill the tuft holes. The first tufts (5) extend between about 8 mm to about 10 mm from the bristle surface (3), as the first tufts (5) are cut into a concave cut, as well be explained in detail on FIG. 2. The first tufts (5) are located centrally on the toothbrush surface (3), between the widthways opposite ends (3C, 3D) of the bristle surface (3), at the distal end (3A) and at the proximal end (3B) of the bristle surface (3). The second tufts (7) are made from second bristles (8) which are split-end, chemically tapered bristles. In FIG. 1, the second tufts (7) are depicted by circles with a dot in the middle. The second bristles (8) are made from a polybutylene terephthalate filament. The second bristles (8) will be described in more detail in the description of FIG. 6. The second tufts (7) have the same diameter as the first tufts (5). The second tufts (7) extend about 12 mm from the bristle surface. The second tufts (7) are located on the margins of the bristle surface (3). In particular, the second tufts (7) are positioned outermost closest to the widthways opposite ends (3C, 3D) on the bristle surface (3). In the embodiment presented in the figures, the first tufts (5) solely comprise first bristles (6) and the second tufts (7) solely comprise second bristles (8). In the embodiment presented in the figures, there are no other tufts besides the first and second tufts (5, 7).
[0081] FIG. 2 shows a vertical cut view of the toothbrush head (1) of FIG. 1, the cut being along the head-handle longitudinal direction (L-L) and centrally between the widthways opposite ends (3C, 3D). A body of the toothbrush head is shown hatched. As can be seen in this view, the first tufts (5) are positioned along the cut line. In FIG. 2, the first tufts (5) are depicted as bars with chamfered free ends. It is to be understood that this is a simplified depiction, and in fact, the first tufts (5) are not monolithic but are composed of first bristles (6), as explained above. The chamfered free ends of the first tufts (5) show that they are cut into a concave cut. The longest bristles of the first tufts (5) are located outermost closest to the distal end (3A) and the proximal end (3B), and have a length 12 of about 10 mm. The shortest bristles of the first tufts (5) are located centrally along the head-handle longitudinal direction (L-L) and have a length l.sub.3 of about 8 mm. In FIG. 2, the second tufts (7) are mainly hidden behind the first tufts (5) and only the ends of the second tufts (7) project stick up behind the first tufts (5). The ends of the second tufts (7) are depicted in FIG. 2 as pointy tips. It is to be understood that this does not mean that the second tufts (7) are monolithic, or are tufts which are cut into a pointy profile, as this is a simplified depiction. In fact the second tufts (7) are tufts of second bristles (8), as explained above, which have all the same length I.sub.1. The length of the second tufts (Ii) is longer than both 12 and 13. All first and second tufts extend from the bristle surface in a bristle direction perpendicular to the bristle surface (3), i.e. in a bristle direction perpendicular to the head-handle longitudinal direction (L-L) and to the widthways direction between the widthways opposite ends (3C, 3D).
[0082] FIG. 3 shows a side view of a toothbrush comprising the toothbrush head of FIG. 1. As in FIG. 2, first tufts (5) are depicted as chamfered bars and second tufts (7) are depicted as pointed bars. In this view it can be seen that the second tufts (7) all have the same length (Ii), whereas the first tufts (5) are cut in a concave cut along the head-handle longitudinal direction (L-L) and that the second tufts (7) are longer than all first tufts (5), and thus project beyond even the longest bristles of the first tufts (5). In the embodiment shown in FIG. 3, the toothbrush head (2) is made from two materials, namely polypropylene and thermoplastic elastomer. The thermoplastic elastomer is used to create an impact protection element (16) which covers the bottom surface and the distal end and the sides of the toothbrush head. The impact protection element (16) is only shown in this FIG. 3. As it is made from thermoplastic elastomer, it prevents cushions hits of the toothbrush against the teeth and gingiva that can occur upon brisk brushing, and gives the toothbrush head a soft and pleasant mouthfeel. In FIG. 3, it is also shown that the toothbrush head (1) is moulded in one piece with a toothbrush handle (2). Between the head (1) and the handle (2) there is formed a neck (14). The handle (2) is inclined vis--vis an axis of the head (1) and neck (14) to stretch out a handle-neck angle (). The handle-neck angle () is about 7. Where the handle (2) merges with the neck (14) there is formed a ledge (17). Ledge (17) is an ergonomic aid for better gripping. Usually, the user will hold the handle (2) with one hand and the thumb-facing side of the forefinger will come to rest on this ledge (17). When brushing, this helps to build adequate brushing pressure and provides for a good grip of the handle (2). Also, in the neck (14) there is formed a ball joint (15). The ball joint (15) reduces risk of damage to teeth or gums by excess brushing pressure.
[0083] FIG. 4 shows an elevated angled top view of a toothbrush head and neck comprising the toothbrush head of FIG. 1. In FIG. 4, the first tufts (5) are depicted schematically as cylinders with chamfered, blunt ends, and the second tufts (7) are depicted as cylinders with pointy ends. The view shows how the first and second tufts (5, 7) extend from the bristle surface (3) in their specific lengths to form, with their free ends, a bristle profile. The bristle profile of the toothbrush head thus is not even but varies due to the concave cut of the first tufts (5) undulating between l.sub.3 and l.sub.2, the length the second tufts Ii, and the specific arrangement of the first and second tufts (5, 7) on the bristle surface (3). It can also be seen that the ball joint (15) is a sphere, embracing the neck (14). The ball joint is made from thermoplastic elastomer, which surrounds a thinned part of the neck (14).
[0084] FIG. 5 shows an individual first bristle (6) extending from the bristle surface (3). The first bristles (6) are unitary end-rounded bristles. The first tufts (5) are made entirely from those first bristles (6). The first bristles (6) are made from unitary nylon filament of a thickness of about 6 mil. First bristles (6) are made from those filaments as known in the art, and first tufts (5) are made from those first bristles (6) and implanted to the bristle surface (3) with the metal anchor technique known in the art.
[0085] FIG. 6 shows a second bristle (8) extending from the bristle surface (3). The second bristles (8) are chemically tapered, split-end bristles. The second tufts (7) are made entirely from second bristles (8). The tufting and implantation in the bristle surface (3) is done via the metal anchor technique, known in the art. The second bristles (8) are made from a composite filament mainly comprising a polybutylene terephthalate. The second bristles (8) have a stem (19) that splits into fours split ends (21). Each of the split ends (21) is chemically tapered towards a point. The length of the second bristle (8) is about 12 mm, measured from the point where the second bristles (8) extend from the bristle surface (3). The stem (19) has a diameter of about 7 mil. As the stem (19) divides into four split ends (21), the split ends (21) have on their widest point, i.e. where they emerge from the stem (19), a diameter of about a fourth of the thickness of the stem (19), thus about 1.75 mil. From there, the split ends (21) taper towards thin, pointy ends. All split ends (21) are equally long. Thus, the second bristles (8) and consequently the second tufts (7) all have the same lengths of about 12 mm.
EXAMPLES
[0086] A manual toothbrush of the present disclosure comprising a toothbrush head with the bristle arrangement as exemplified was assessed in terms of plaque removal efficacy (example 1) and gingival margin cleaning (example 2).
[0087] Example 1: The test was a clinically validated brushing robot test comprising on a model of human teeth. The efficacy of plaque removal was assessed using an automated planimetrical plaque assessment analysing 30 fields per tooth. Therefore, a human tooth model was stained with artificial plaque, subjected to a defined robot brushing in anatomic position, and the reduction of stain from the 30 predefined areas of the surface of each tooth was assessed with an automated optical method. Special emphasis was on the high risk areas of the teeth: root surfaces or root fields, areas just above the root surfaces and close to the gumline, especially in the interproximal regions, where dental plaque is hard to remove, and which are most relevant for the prevention and alleviation of periodontal disease. The toothbrush according to the invention as described in FIG. 3 was compared to a reference toothbrush comprising end rounded Nylon bristles with a diameter of 6 mil and without a handle implement. The head size, shape, and tuft hole placement with 33 tufts of the reference toothbrush was similar to the toothbrushes of the invention. Brushing was performed at a brushing force of 2.5N which corresponds to a gentle brushing force. Three rounds of tests were run: horizontal, rotating, and vertical brushing movement, each with seven replicates.
[0088] The experiment showed that the toothbrush of the invention achieves higher total percentage of plaque removal on all 30 areas measured than the reference toothbrush in all three brushing movements. The same was found looking at the high risk areas individually, namely the root surfaces and the areas just above the root surfaces close to the gumline. The difference in plaque removal from the areas close to the gumline was more pronounced buccally than lingually. Toothbrushes with the bristle configuration of the present invention thus are optimal for plaque control at all risk areas, contributing to prevent dental caries and gingivitis.
[0089] Example 2: For example 2, an artificial plaque-covered pressure sensitive substrate was used to evaluate the ability of toothbrush bristles to remove plaque at the gingival margin around posterior tooth shapes. This process of plaque removal is referred to as Gingival Margin Cleaning (GMC) in the art. Simulated gingivae positioned over simulated posterior teeth were prepared from self-curing dental acrylic. The marginal anatomy was developed using dental textbook guidelines. The space between the acrylic gingivae and the simulated teeth was 0.2 mm. The artificial plaque pressure sensitive substrate was placed under the simulated gingivae and around posterior-shaped teeth and was hydrated with room temperature tap water for 15 seconds prior to the start of the brushing. The brush head and plaque substrate were constantly sprayed with water during brushing. The brushing technique involved a horizontal brushing motion. The toothbrush to be tested was aligned with the papillae of the gingival margin, and the brushing apparatus was set to brush for 15 seconds at two strokes per second with a 15 mm stroke length with the bristles placed at 90 to the tooth surface and 250 g brushing weight. For Gingival Margin Cleaning (GMC), the length of the artificial plaque deposit removed at the junction of the simulated gingival margin was recorded. Readings were measured in mm with 3 magnification. The toothbrushes tested were visually examined before and after the completion of each brushing cycle for bristle integrity. Descriptive statistics (mean and standard deviation) were calculated for the products tested. An analysis of variance (ANOVA) indicated at least one significant difference in mean GMC values between the toothbrushes. A post-hoc Tukey test for the pairwise comparison identified the specific significant differences in mean GMC, using a significance level of 0.05. The experiment showed that the toothbrush according to the invention as described in FIG. 3 achieves significantly higher GMC values (mean: 7.15 mm, SD: 2.96) than the reference toothbrush of example 1 (mean: 3.25, SD: 1.97).
