GB2457665A - Tooth Cleaning Device - Google Patents

TOOTI-1 CLEANING DEVICES This invention relates to tooth cleaning devices and, in particular, to devices which overcome a variety of disadvantages associated with conventional toothbrushes.

It is widely accepted that dental hygiene is important and particularly in the developed Western world, where the normal diet contains much material inimical to good dental hygiene, the practice of brushing one's teeth at least once a day is essentially universal. The standard approach is to use a brush which is manipulated by hand together with an appropriate dentifrice material which may be of powder form, but is more often of creamy or pasty form.

The brush may be a simple passive brush on the end of a handle which is manipulated by the user as desired, or it may be a more sophisticated vibrating and/or rotating brush driven, for example, by an electric motor.

The patent literature is replete with suggestions for different toothbrush constructions, but very little of the extensive body of suggestions made in the patent literature has been successfully commercialised. The vast majority of tooth cleansing is still carried out using a conventional non-electrical toothbrush manipulated by hand. This can provide satisfactory results if the brush is properly manipulated, but, as is clear from much research published in the dental literature, very often people do not brush correctly and this can in particular lead to inadequate cleansing with adverse results for dental health.

Particular problems are also encountered by the elderly or infirm who may have difficulty in actually brushing their teeth, particularly those whose grip and manual dexterity is adversely affected by arthritis.

WO 2005/087044, US-A-4757570 and GB-A-2377167 all disclose toothbrushes which are intended to provide better cleaning and which have back-to-back bristle-lined channels mounted on a handle. In each case, the brush is used in conventional fashion by moving the head of the brush along the rows of teeth, and thus cleaning relies wholly on manual action by the user causing the brush to move across the surfaces of the teeth. The efficiency of cleaning can vary widely, as different users operate a brush in different ways.

I have now found that the efficiency of tooth cleaning may be materially improved by the use of a tooth-cleaning device which provides a brushing action generated by the movement of the user's jaws against the device which is contained between them. The brushing is thus effected in a "hands-free" fashion. By suitable design of the device, the brushing action may be greatly improved or enhanced.

Generally, the present invention provides a tooth-cleaning device consisting of a handle carrying a brush head comprising a pair of back-to-back channels, each channel having a base and side walls, wherein the side walls carry a flexible resilient brush structure, the walls being spaced apart sufficiently to allow the insertion of a tooth or row of teeth between them and the brush structure is sufficiently deep to engage the opposite sides of a tooth or row of teeth so inserted and wherein the channels are configured so that alternately pressing on, and relieving pressure on, the bases of the channels causes the walls of the channels to move towards and away from one another. This applies bristle pressure to the tooth surface and, together with the sideways motion of the bristles across the tooth surface, generates a forceful brushing action when the device is used.

The tooth cleaning devices of the present invention are used by locating the head of the device in the mouth with one channel facing the upper row of teeth and the other the lower row of teeth. The user then simply opens and closes the lower jaw which exerts a brushing action on those teeth which are located between the brush structures on the oppositely facing side walls of the channels. The wall design ensures that simple opening and closing of the mouth guides the lower jaw into its normal centric occlusion. As the jaws close, the teeth press on the base of the channels and cause the brush structures on the sides of the channels to move laterally, so that as well as the brushing action being vertical up and down the sides of the tooth, a component of the brushing movement is also directed in and out towards and away from the tooth surface.

After this has been done for a short while, the handle can be grasped to move the head of the device along the rows of teeth, and the action of moving the jaws together and apart then repeated until the entire dentition has been cleaned in this way.

Because the handle is not used to effect the brushing action, but simply to position the head in the mouth, it does not have to be a rigid elongate handle of known type. Instead, a thin plastics rod or elongate tab may extend from the head, and may, for example, be moulded integrally therewith. The length of the handle does not have to be very great, just sufficient to allow easy manipulation. The handle may, when the device is in use, protrude between the user's lips, which seal around it. The action of closing into centric occlusion to clean the teeth is accordingly carried out with the lips sealed, thus preventing any extra-oral splashing of dentifrice.

This provides a further advantage of devices according to the present invention: they can be used while the user is walking around, for example during dressing or preparing breakfast or walking to the refrigerator to fill a glass with fruit juice. The device is essentially a "hands-free" device, and thus also very easy to use by those whose hands are not able to use a conventional toothbrush, for example due to arthritis.

In a particularly preferred embodiment, the two oppositely facing channels have a W-shaped cross-section, and the material of manufacture of the channels is so chosen that the opposed bases of the two channels constitute a hollow compressible tube extending from one side of the brush head to the other. As this occurs, the side walls of each channel approach one another, pivoting around the edges of the tube where the two channel sections are joined, so the opening and closing action of the jaws provides both relative movement vertically in each channel as the teeth approach one another and are moved away from one another, and horizontally due to the channel walls moving towards and away from the tooth or teeth located between them.

This enhances the cleansing action.

While it is possible to use the device with the manual application of a dentifrice shortly before it is inserted into the mouth, it is preferred that the dentifrice is supplied as part of a single use head for the device. In a preferred approach, the dentifrice is provided in the form of a cream or paste which is sealed in an appropriate rupturable membrane which is ruptured as soon as the device is put to use, thus releasing the dentifrice which spreads over the teeth and the tooth-engaging structures as the device is used.

Alternatively, the device may be presented in an appropriate form of packaging, for example a plastics film wrapper or capsule, which acts to package and protect it until use and which stops loss of a powdery, pasty or creamy dentifrice material located on or adjacent the brush structures.

One particular way of providing dentifrice is to configure the channels so that there is a cavity between them from which dentifrice may be expelled when the user bites on the device at the start of use.

The size of the head may vary, and is usually chosen as a compromise between a smaller size (which is easier to manouevre in the mouth) and a larger size (which interacts with more teeth at a time and so reduces brushing time). A typical channel length is 10 to 15 mm, preferably around 12mm.

The devices in accordance with the invention are preferably made by a simple moulding process, preferably as an integral one-piece moulding which it needed can then be deformed or welded to provide the final structure.

Any alternative convenient manufacturing process may be used, however, including forming parts of the device by extrusion and cutting, and including the step of joining a bristle array to the sides of each channel.

The materials from which the devices according to the present invention may be made may vary, with a wide range of plastics materials being available in commerce from which such devices may be moulded. Highly preferred are such materials which are formulated to biodegrade since the discarded device is then less of a burden on the environment.

The invention is illustrated by way of example with reference to embodiments which are shown in the accompanying sheet of drawings, in which: Figure 1 is a perspective view of a first embodiment of a tooth-cleaning device in accordance with the present invention; Figure 2 is a perspective view of an alternative embodiment; and Figure 3 is a perspective view of a moulded brush head.

Referring to Figure 1, this shows a pair of short channel members 1, 2, the bases of which are fixed together at their edges, for example by ultrasonic seam welding. The base of each of the channels, denoted 3 and 4 in Figure 1, is arched so that the two bases have a space between them.

On the inner face of each of the sides of channels 1 and 2, there is a brush member 6, with the bristles pointing towards one another from the opposite side walls of each channel. The spacing between the ends of the bristles is less than the width of a human tooth so that, if the device illustrated in Figure 1 is placed in the mouth, teeth from the upper and lower jaws may be inserted into channels 1 and 2 respectively. Simple opening and closing of the mouth guides the teeth into the channels and once that has happened, the user opens and closes his or her lower jaw so the teeth move, generally speaking, relative to the channel in the direction indicated by the double-headedarrow7.

Each time the teeth approach one another, they compress the bases of the channels 3 and 4 together and, as a result, the entire channel is flattened and the walls move towards one another, and then move apart again when the bite holding bases 3 and 4 together is removed. The corners at the base of the channel do not change shape materially, so the walls essentially rotate about their respective bases towards and away from one another, i.e the sides of the channel move in an oscillating fashion to and fro as indicated by double-headed arrow 8 in Figure 1.

The space between the bases 3 and 4 of channels 1 and 2 is filled with a pasty or creamy dentifrice and the bases 3 and 4 may be apertured to allow the dentifrice to move directly into the space between the two brushes 6 when the device is put to use.

The alternative structure shown in Figure 2 works in somewhat similar fashion, though instead of a pair of opposed side walls which essentially pivot around the base to approach one another and move away from one another, the movement of the side walls is slightly less and effected when an extruded tubular portion 11 is squeezed together, that tubular portion being in the centre of the horizontal bar in an H section extrusion 10. The facing inner sides of the verticals of the H section 10 are faced with the brush or bristle structure 12.

The relative motion of the bristle structures 12 one to another together and apart is not very substantial, but the brushing action which may be achieved on the sides of the teeth is highly effective. Although it might be thought that in use the relative movement between the bristles 12 and the surface of the tooth would be relatively minor compared with the structure shown in Figure 1, it is found to be perfectly sufficient for the purpose and good cleansing action is achieved when the teeth of the user are moved in the direction of double-headed arrows 14 in the upper and lower back-to-back channel sections formed by the H section extrusion 10.

Figure 3 shows a perspective view of a further device in accordance with the invention, consisting of an integrally moulded configuration comprising two W-section channel members 30, each of which consists of a base 31 and integrally moulded spikes 32 which constitute the bristles. A simple integrally moulded handle 34 extends to one side.