WO2010023581A1

WO2010023581A1 - Interproximal toothbrush

Info

Publication number: WO2010023581A1
Application number: PCT/IB2009/053567
Authority: WO
Inventors: Garrett Kotlarchik; Jelte Steur
Original assignee: Koninklijke Philips Electronics NV
Current assignee: Koninklijke Philips NV
Priority date: 2008-08-25
Filing date: 2009-08-12
Publication date: 2010-03-04
Anticipated expiration: 2011-02-25

Abstract

The interproximal toothbrush includes a toothbrush body having a head portion (10. First and second sets (14, 16, 18, 20, 22) of bristle tufts extend from the head portion at respective angles such that the bristles form a triangular bristle configuration. A first set of bristles (14, 18, 22) is positioned at an angle of approximately 32.5°-47.5° for the vertical, while a second set of bristles (16, 20), alternating with the first set of bristles, is also positioned at the same angle of approximately 32.5°-47.5° from the vertical, in the opposing direction. The bristles in each set slightly overlap the longitudinal side surfaces of the bristles in the other set, providing bristle tuft end cleaning surfaces for the interproximal surfaces.

Description

INTERPROXIMAL TOOTHBRUSH

This invention relates generally to bristle tuft arrangements for toothbrushes, and more specifically concerns a toothbrush bristle tuft arrangement adapted specifically for cleaning interproximal regions of the teeth.

It is well known that removal of plaque in the interproximal spaces between the teeth is quite important for good oral health. It is not sufficient to clean only the relatively flat front (outwardly facing) surfaces of the teeth. Due to the geometry of the interproximal spaces, however, they are typically difficult areas to clean with conventional toothbrushes and, hence, less effective plaque removal occurs in these areas. Conventional toothbrushes have been modified in the past to improve interproximal cleaning performance. These modifications, including specific features such as rubber paddles, angled tufts and tufts of varying lengths on the toothbrush head, all have had rather limited success in interproximal cleaning. Many toothbrushes having specific bristle configurations which attempt to clean the front portions of the teeth as well as interproximal portions produce compromised performance for both areas. The bristles which are intended to clean the front of the teeth inhibit the bristles intended to clean the interproximal areas from penetrating deep into the interproximal spaces. Besides performance, there is also frequently a guidance issue for the bristles. The bristle tufts are not designed to give the user definitive feedback as to when they are situated in an interproximal space, as opposed to the front surfaces of the teeth, i.e. the user cannot tell when the toothbrush bristles are positioned in an interproximal space.

Further, the bristles are typically arranged to produce a perpendicular action relative to the brush areas, which produces a good cleaning of the front surface portions of the teeth, but tend to slide over the interproximal surfaces, until they become bunched together and thus unable to perform any action needed for plaque removal in the interproximal spaces.

While some toothbrushes include some angled bristles, such bristle design has not been optimized, nor is the bristle tuft angle of such arrangements sufficient to provide a direct plaque removal action against the interproximal surfaces. Accordingly, it is desirable to have a toothbrush which is designed specifically to effectively clean interproximal surfaces of the teeth.

Accordingly, a toothbrush for cleaning interproximal teeth is disclosed, comprising: a toothbrush body having a toothbrush head portion; a first set of bristle tufts with bristle tuft ends extending from the head portion at an angle in the range of 25°-55° from the vertical; and a second set of bristle tufts having bristle tuft ends extending from the head portion in an opposing angular direction from the first set, in the range of 25°-55° from the vertical, wherein the bristle tuft ends of the first and second sets of bristles, respectively, overlap slightly longitudinal side surfaces of the other set of bristles, so that as the toothbrush is positioned in an interproximal space, the bristle tuft ends contact the interproximal surfaces of the teeth, cleaning them by brush action.

Figure 1 is a side elevational view of a toothbrush head with one embodiment of a bristle tuft arrangement of the present invention. Figure 2 is a perspective view of the toothbrush head with the bristle tuft arrangement of Figure 1.

Figures 1 and 2 show a toothbrush head 10 with a bristle tuft arrangement referred to generally at 12 designed specifically to effectively clean interproximal areas of the teeth. In the embodiment shown, the bristle tuft arrangement includes a total of five columns of bristle tufts 14, 16, 18, 20 and 22, three of which, 14, 18 and 20, are angled in one direction, while the other two 16 and 22 are angled in the opposing direction, generally forming triangles defined by adjacent bristle tuft columns. In the embodiment shown, each bristle tuft column 14, 18 and 20 includes two rows of bristle tufts 26 and 28 and each bristle tuft column 16 and 20 includes two rows of bristle tufts 30 and 32.

While the embodiment shown includes a total of five alternating bristle tuft columns with two bristle tuft rows in each column, a different configuration can be used. For instance, while two bristle tuft rows in each column is preferred, one row or three rows can also be used. In some cases, one set of columns could have a different number of rows than the other set. The number of columns can also vary, although for a conventional size brushhead, the number of columns could be either four or six, in addition to five. Preferably, the bristle tuft columns will alternate in angular direction, but not necessarily, i.e. two adjacent columns could extend in the same direction.

In the embodiment shown, the bristle tuft angle will preferably vary between 32.5° and 47.5° from the vertical, while a broader range is between 25° and 55° from the vertical. The preferred angle is approximately 40°. Preferably the opposing rows will have the same angle, e.g. if the bristle tufts in one direction have an angle of 40°, the bristle tufts in the opposing direction will also have an angle of approximately 40°. The tips of each column of bristle tufts will typically extend beyond the longitudinal surface of the adjacent oppositely angled column of bristle tufts by 1 mm ± 0.5 mm, as indicated by numeral 35. This will provide good direct bristle action on the interproximal teeth. The effective cleaning surface of the above bristle configuration, i.e. the outside dimension of the combined two rows, shown as dimension 36 in Figure 1, will be preferably 3 mm, with a range of 1-5 mm being effective. The dimensions of bristle tufts themselves also are important for effective cleaning. The length of the bristles, for nylon, as an example, will typically be within the range of 6 mm to 16 mm, with a preferred value of 11 mm, depending on the diameter of the bristles. The bristle diameter will preferably be between 4-7 mils, with the bristle and/or bristle tuft cross-section having various configurations, including circular, oval or diamond-shaped or some other shape. Typically, the bristles tuft will comprise 44 bristle strands of 5 mil bristles, or 22 strands for 7 mil strands.

The above arrangement has the advantage of effectively cleaning the interproximal areas. As discussed above, with the tufts angled in opposing directions and overlapping so as to form triangles, the resulting geometry will guide the bristle arrangement firmly into the interproximal regions, providing an indication to the user of the position of the toothbrush. When the user moves the brush sideways, the bristles that reach into the interproximal space have to move out of that interproximal space and go over the front surface of the tooth before they can reach into the next interproximal space. The resistance of the bristles against going sideways is felt in the handle of the toothbrush by the user. This feedback indicates whether the bristles are effectively reaching into the interproximal spaces. Conventional bristles that reach into the interproximal spaces tend to resist by virtue of their bending stiffness because the lateral force is mostly perpendicular to their orientation.

The advantage of the cross-angled tufts of this arrangement is that the bristle orientation is more in line with the movement of the brush as it is guided through the mouth by the user. Accordingly, the resistance felt by the user is caused by the buckling and compressive stiffness of the tufts as well as the bending stiffness. This results in a substantially greater force that can be more clearly felt by the user, providing a better indication of the position of the toothbrush. While the angle of the bristle tufts may vary, while still providing an effective cleaning benefit, as indicated above, a preferred tuft angle range of 32.5°-47.5° from the vertical for each row, with an included angle of 65°-95° between the columns, will typically provide the most effective cleaning. The preferred tuft angle of approximately 40° will result in an included angle between the opposing tufts of approximately 80°. The cross-angled tufts of this arrangement result in the bristles pushing substantially perpendicularly to the interproximal surfaces, which limits the deflection of the bristles and limits the loss of applied force to the teeth.

In a modification of the above arrangement, perpendicular or straight bristles can be added to the brushhead at opposing longitudinal ends of the set of angled bristle tufts, as shown in Figure 1. The straight bristles 50 can be at either one or both ends of the set of angled tufts, and will extend substantially across the toothbrush head for the width of the angled bristles. Typically, the straight bristles will not be shorter than 6 mm and must be shorter than the peak 44 of the angled tufts. A range for this distance will be approximately 3.8 mm-5.9 mm, with 4.3 mm being preferred, as shown by dimension 56 in Figure 1. This arrangement provides an ability for the toothbrush to clean front surface portions of the teeth in addition to the interproximal spaces.

Hence, a toothbrush designed specifically for cleaning the interproximal spaces of the teeth uses cross-angled bristles to provide directly effective cleaning force against the interproximal surfaces as well as a reliable indication to the user that the toothbrush is located in the interproximal spaces. It should be understood that the interproximal design could be used for both manual and power toothbrushes. Although a preferred embodiment of the invention has been disclosed here for the purposes of illustration, it should be understood that various changes, modifications and substitutions may be incorporated in the embodiment without departing from the spirit of the invention, which is defined by the claims which follow.

Claims

1. A toothbrush for cleaning interproximal teeth, comprising: a toothbrush body having a toothbrush head portion (10); a first set of bristle tufts (14, 18, 20) with bristle tuft ends extending from the head portion at an angle in the range of 25°-55° from the vertical; and a second set of bristle tufts (16, 22) having bristle tuft ends extending from the head portion in an opposing angular direction from the first set, in the range of 25°-55° from the vertical, wherein the bristle tuft ends of the first and second sets of bristles, respectively, overlap slightly longitudinal side surfaces of the other set of bristles, so that as the toothbrush is positioned in an interproximal space, the bristle tuft ends contact the interproximal surfaces of the teeth, cleaning them by brush action.

2. The toothbrush of claim 1, wherein the angles of the first and second bristle tufts are approximately the same.

3. The toothbrush of claim 1, wherein the bristle overlap is 1 mm ± 0.5 mm.

4. The toothbrush of claim 2, wherein the angle is within the range of

32.5°-47.5°.

5. The toothbrush of claim 2, wherein the angle is approximately 40°.

6. The toothbrush of claim 1 , wherein the bristle arrangement comprises three columns of bristle tufts in a first set and two columns of bristle tufts in a second set, the columns in the first and second sets alternating, and further includes two rows of bristle tufts in each column.

7. The toothbrush of claim 1, wherein the distance covered by the bristles for cleaning in each column is within the range of 1 -5 mm. The toothbrush of claim 6, wherein the distance is approximately

3 mm.

9. The toothbrush of claim 1 , wherein the bristles have a diameter within the range of 4-7 mm and a length of approximately 11 mm.

10. The toothbrush of claim 1, including a row (50) of straight, vertical bristles at one or both ends of the first and second sets of bristles, wherein the straight bristles have a top edge which is approximately within the range of 3.8 mm to 5.9 mm shorter than a peak comprised of the first and second sets of bristles meeting.

11. The toothbrush of claim 9, wherein the distance is approximately 4.3 mm.