GB2566021A - Toothbrush - Google Patents

Abstract

A toothbrush 10 comprises a body 12 having an elongate shaft 14 and a curved head 16. A first plurality of tooth bristles 18 and a second plurality of buccal or cheek cleansing bristles 20 project from the head. The second plurality of bristles are positioned at a different location and project in a different direction relative to the first plurality of bristles. The first plurality of bristles may project from a concave side of the head. In a preferred embodiment, the second plurality of bristles may have a smaller average spacing between the bristles than the first plurality of bristles. A third plurality of bristles 32 comprising buccal cleansing bristles may project from the head. The shaft may have a flexible portion proximal to the head, and a haptic feedback device 50 in the flexible portion may indicate when excess pressure is applied to the teeth. The toothbrush may further comprise a tongue scraper 34 at a distal end of the shaft. In another embodiment, the toothbrush head may include a rotating wheel 116 surrounding a central hub 118.

Description

The present invention relates to toothbrushes, and in particular, toothbrushes with curvate heads for improved oral hygiene.

Toothbrushes are commonly used to clean a person’s teeth, and may be used privately by individuals, as well as by dental hygienists and dentists on their patients. A conventional toothbrush has a body having a handle portion, and a head portion, the head portion having a plurality of bristles projecting from it. In early designs of toothbrushes, such as that disclosed in US patent 18,653, the head portion of the toothbrush was substantially flat, and typically lay parallel to the handle. However, such a design was found to be disadvantageous, due to the difficulty of cleaning the premolars, also known as bicuspids, and molars while avoiding contact of the toothbrush handle with the user’s teeth and/or jaw bone.

A toothbrush design well known in the art, which partially addresses this problem, has a substantially flat head which is slanted with respect to the handle. This reduces contact between the handle and the teeth on brushing the molars. However, in practice, it is difficult for a user to orient such toothbrushes to clean the molars; brushing the back of the third molar is particularly difficult. Users may also find cleaning partially erupted molars uncomfortable with known toothbrushes, increasing the risk of cavities, caries and other forms of tooth decay.

General requirements and test methods for manual toothbrushes are defined by ISO standard 20126:2012, while general requirements and test methods for powered toothbrushes are defined by ISO standard 20127:2005.

The incidence of premolar and molar caries is typically found to be high among study populations, especially paediatric study populations. In one large cohort study of UK children aged 3 to 6 in North West England (Br Dent J 2008 205:E14), over 25% of subjects developed primary molar caries over the three year study period.

Oral mucositis, the inflammation and ulceration of the buccal mucosa, may be caused by chemotherapeutic or radiotherapeutic treatment of cancer, and is typically severely painful. Regular cleansing of the buccal mucosa reduces the risk of bacterial infection in the case of mucositis, and thus increases recovery time. Furthermore, cleaning of the buccal mucosa by healthy patients is known to reduce the risk of tooth, gum and mouth infection. However, toothbrushes known in the art are not adapted to allow users to clean the buccal mucosa; the tooth-brushing bristles are typically too rough to be applied directly to the buccal mucosa.

The present invention seeks to provide a solution to these problems.

According to an aspect of the invention, there is provided a toothbrush comprising a body having a substantially straight elongate shaft and a head which is at least in part curvate with respect to the shaft, a first plurality of bristles projecting from the head, and a second plurality of bristles projecting from, or adjacent to, the head, the first plurality of bristles comprising a plurality of tooth bristles, and the second plurality of bristles comprising a plurality of buccal cleansing bristles, the second plurality of bristles being positioned at a different location to the first plurality of bristles, and projecting in a different direction relative to the first plurality of bristles.

Such a toothbrush advantageously facilitates the cleaning of a user’s molars, gums, buccal mucosa and palate. The tooth bristles projecting from the head may be applied to a users’ molar, with simultaneous contact of the buccal cleansing bristles with the buccal mucosa, gums and/or palate, allowing effective cleaning of the mouth.

Beneficially, the head may have a convex side and a concave side, and the first plurality of bristles may project from the concave side of the head. During use of the toothbrush, this may allow the tooth bristles of the head to contact the coronal surface of a tooth, and the lingual or palatal side of the same tooth, especially when the tooth is a molar. The tooth bristles of the head may also in use contact the vestibular and posterior sides of a third molar, or the vestibular side of a tooth and the coronal surface thereof.

The second plurality of bristles preferably projects from or adjacent to the convex side of the head. This may increase contact between the buccal cleansing bristles of the second plurality of bristles and the buccal mucosa of the user.

The second plurality of bristles may have a smaller average spacing between the bristles than the first plurality of bristles. Finer bristles are preferable for the cleansing of the buccal mucosa.

Most preferably, the thickness of each bristle of the first plurality of bristles may be in the range 0.15 to 0.35 mm, the average spacing of the first plurality of bristles may be in the range 0.25 mm and 0.4 mm, and the average length of the first plurality of bristles may be in the range 0.75 cm to 1 cm; and the thickness of each bristle of the second plurality of bristles may be in the range 0.05 mm to 0.12 mm, the average spacing of the second plurality of bristles may be in the range 0.025 mm to 0.2 mm, and the average length of the second plurality of bristles may be in the range 0.35 cm to 0.5 cm.

Additionally or alternatively, a third plurality of bristles may project from and/or adjacent to the head, the third plurality of bristles comprising a plurality of buccal cleansing bristles. Providing a third plurality of bristles may result in the greater contact of the buccal cleansing bristles with the user’s gums, buccal mucosa and palate, as the toothbrush is used. The third plurality of bristles preferably projects at least in part from the shaft, proximal to the head, to increase the surface area contact with the buccal mucosa and/or palate in use.

In one embodiment, the third plurality of bristles may have a greater average spacing between the bristles than the first plurality of bristles and/or the second plurality of bristles. If the third plurality of bristles are designed for cleansing the hard palate of the user, a more spaced apart distribution of bristles may be preferable, to allow cleansing of raised surface features of the hard palate, such as a torus palatinus, without bending the bristles in use.

Beneficially, the thickness of each bristle of the third plurality of bristles may be in the range 0.45 mm to 0.60 mm, the average spacing of the third plurality of bristles is in the range 0.5 mm and 2 mm, and the average length of the third plurality of bristles is in the range 1.5 cm to 2 cm.

Preferably, the third plurality of bristles projects substantially orthogonally to the first and second pluralities of bristles, the first and second pluralities of bristles projecting in opposite directions either side of the body, thereby providing a cruciform arrangement of bristles at or adjacent to the head. This arrangement may advantageously allow simultaneous cleansing of the user’s teeth, gums, buccal mucosa and palate, for at least some locations of the user’s mouth.

Beneficially, the shaft may have a flexible portion proximal to the head, and the toothbrush may further comprise a haptic feedback device in the said flexible portion of the shaft. Advantageously, such a design may alert the user by providing haptic feedback when excess pressure is applied to the teeth with the toothbrush.

In an alternative embodiment of the same aspect of the invention, the head may comprise a hub and a wheel rotatably mounted therearound. In this case, the hub is preferably concentric to the wheel. The rotatable wheel may advantageously be applied to the buccal mucosa, particularly while the hub contacts the coronal surface of a tooth.

As such, beneficially the first plurality of bristles may project from the hub, and the second plurality of bristles may project from the wheel.

Optionally, the hub and the wheel are coupled by a plurality of spokes projecting from the hub. This may allow the hub and the wheel to be driven by a single motor.

The toothbrush may comprise a first motor and a control circuit operatively connected to the first motor, the first motor and the control circuit being enclosed at least in part within the body, the first motor being coupled to the head, and the control circuit being operable by a user-operable element to activate the first motor and thereby rotate the head.

In this case the motor may be coupled to the wheel of the head, and the toothbrush may further comprise a second motor coupled to the hub of the head, operatively connected to the control circuit and enclosed at least in part within the body such that the control circuit is operable by a user-operable element to activate the first motor and the second motor, to provide contrary motion of the wheel and the hub with respect to each other. This arrangement may be particularly advantageous, as it allows the wheel and the hub to be rotated at different speeds to allow effective cleansing of the teeth and gums, buccal mucosa and/or palate simultaneously.

The toothbrush may also comprise a user-operable button which is coupled to the control circuit to activate the first and/or second motor. Such a button allows easy activation of the toothbrush. The toothbrush could also have a status indicator light on the body, which may indicate a toothbrush activation status.

For either embodiment of the toothbrush hereinbefore described, a tongue scraper may be provided at an end of the body distal to the head. Advantageously, this may allow the user to also cleanse their tongue with the toothbrush. For economy of manufacture, the tongue scraper most preferably is integrally formed with the shaft.

The invention will now be more particularly described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 shows a side view of a first embodiment of a toothbrush in accordance with the invention;

Figure 2 shows a top view of the toothbrush shown in Figure 1;

Figure 3 shows a cross-sectional view of the toothbrush shown in Figure 1 and Figure 2, in the section A-A;

Figure 4 shows a front view of the toothbrush shown in Figures 1 to 3; and

Figure 5 shows a front view of a second embodiment of a toothbrush in accordance with the invention.

Referring to Figures 1 to 4 of the drawings, there is shown a toothbrush 10, with a body 12 having an elongate shaft 14, and a head 16 which is at least in part curvate with respect to the shaft 14. A first plurality of bristles 18 projects from one location on the head 16, while a second plurality of bristles 20 projects from a different location of the head 16, in a different direction relative to the first plurality of bristles 18.

The body 12 of the toothbrush 10 may preferably be formed from a dental-grade polymeric material. Polypropylene is most preferable, as it is of low cost and widely recycled. Bioplastics, such as thermoplastic starches, may also be considered, especially if the toothbrush 10 was designed to be disposable. The body 12 of the toothbrush 10 could also conceivably be formed of any other dentally-safe polymeric material, wood or metal.

As shown in Figure 1 of the drawings, the shaft 14 is preferably substantially straight, and may be integrally formed with the head 16 of the toothbrush 10. The shaft 14 is designed to be held by a user as a handle for the toothbrush 10. As toothbrush handles and/or user’s hands typically become wet in use, it may be advantageous for the shaft 14 to have a textured surface (not shown) to ensure adequate friction between the shaft 14 and a user’s hand, to prevent the toothbrush 10 from slipping in the user’s hand during use. The shaft could also be ergonomically designed to provide an improved fit within a user’s hand. For instance, the shaft could include surface protrusions which sit between the fingers of a user’s hand, when clenched around the shaft, and/or have a longitudinal extent which is non-linear, such as including a kink or cant to more easily orient the head when in use.

At one end of the shaft 14 there is provided the head 16 of the toothbrush 10. At another end of the shaft 14, distal to the head 16, there may be provided a tongue scraper 22.

Between the head 16 and the tongue scraper 22, the diameter of the shaft 14 may preferably be uniform.

In the embodiment shown in Figures 1 to 4 of the drawings, the head 16 is integrally formed with the shaft 14. Provision of the head as a detachable component may also be considered; this would be advantageous as it would allow a used head to be replaced without requiring replacement of the body of the toothbrush.

The first plurality of bristles 18, which include a plurality of tooth bristles adapted specifically for the cleansing of teeth, project from the head. The second plurality of bristles, including a plurality of bristles for buccal cleansing, also may project from the head 16. Buccal cleansing is understood to include, but not be limited to, the cleansing of gums also known as gingiva, buccal mucosa, tongue, tonsils, uvula, and the hard and/or soft palate of the mouth.

The head 16 is at least in part curvate. A lower portion 16a of the head 16 may have a similar or identical diameter to the shaft 14 and extend in a direction substantially the same as that defined by the extent of the shaft 14. An upper portion 16b of the head 16 preferably is curvate, such that an end 24 of the upper portion 16b of the head 16 is angled with respect to the shaft 14, preferably perpendicularly, or substantially perpendicularly.

The upper portion 16b of the head 16 may have a similar diameter to the shaft 14 and the lower portion 16a of the head 16 at an interface 26 between the lower and upper portions 16a, 16b of the head 16, and taper towards the end 24 of the upper portion 16b of the head 16. Alternatively, the upper and lower portions of the head may have uniform diameter.

The curvature of the upper portion 16b of the head 16 may define a concave side 28 and a convex side 30 of the head 16 of the toothbrush 10. The first plurality of bristles 18 may project from the concave side 28 of the head 16, preferably across the full extent of the curvature of the upper portion 16b of the head 16. The second plurality of bristles 20 may project from the convex side 30 of the head 16, or on the shaft 14 adjacent to the convex side 30 of the head 16. Particularly when the upper portion 16b of the head 16 is curvate, and the lower portion 16a of the head 16 is substantially non-curvate, it may be preferable for the second plurality of bristles 20 to project only from the lower portion 16a of the convex side 30 of the head 16, and not on the curvate upper portion 16b, as shown.

There may be a third plurality of bristles 32 projecting from the upper and/or lower portions 16a, 16b of the head 16, and/or on the shaft 14 adjacent to the head 16. The third plurality of bristles 32 preferably projects perpendicularly or substantially perpendicularly to both the first and second pluralities of bristles 18, 20. As illustrated in Figures 2, 3 and 4 of the drawings, the third plurality of bristles 32 may project independently from two faces of the head 16, on either side of the body 12; such faces may be at least substantially parallel. In this case, the first, second and third plurality of bristles 18, 20, 32 may together define a cruciform arrangement of bristles.

The bristles of the first plurality of bristles 18, hereinafter referred to as the first bristles, may preferably be formed of polyamide 6,12, which has low moisture absorbance and high strength. Polyamide 6,6, polyamide 11, or a polyester, such as polyethylene terephthalate, could also be considered, as well as co-polymers of any of these polymers. Horse hair may also be preferable due to its superior bend recovery, preventing deformation of the brush, but is known to deteriorate quickly under warehouse storage conditions relative to polymer bristles. In any case, a material of Shore hardness greater than 30 is typically preferred to ensure a firm brush. The average spacing of the first bristles 18 is preferably between 0.05 and 2 mm, and most preferably between 0.25 and 0.4 mm. The preferred average length of the first bristles 18 would be between 0.5 and 1.5 cm, and most preferably between 0.75 cm and 1 cm, although conceivably the first bristles may vary in length for any one toothbrush, to provide a contoured brush profile for better tooth engagement. Preferably, the thickness of each first bristle 18 is between 0.05 and 0.65 mm, and most preferably between 0.15 and 0.35 mm.

The bristles of the second plurality of bristles 20, hereinafter referred to as the second bristles, may preferably be formed of polyamide 11, which has a lower Shore hardness, and is more flexible than, polyamide 6,12. The second bristles 20 could also be animal hair bristles, formed from horse hair, or a speciality soft hair such as horse lower abdomen soft hair or ox ear hair, or another material different to that chosen for the first bristles 18.

However, the second bristles 20 may be formed from polyamide 6,12, or any another material chosen for the first bristles 18; in this case, the second bristles 20 may preferably be finer, and optionally with lower average spacing than the first bristles 18, to achieve the same technical effect. The average spacing of the second bristles 20 is preferably between 0.015 and 1 mm, and most preferably between 0.025 and 0.2 mm. The preferred average length of the second bristles 20 would be between 0.25 cm and 1 cm, and most preferably between 0.35 cm and 0.5 cm, although conceivably the second bristles may vary in length for any one toothbrush, to provide a contoured brush profile for effective cleaning of portions of the buccal mucosa which substantially protrude into the mouth, such as the palatoglossal arch.

However, it could also be advantageous if the second bristles do not vary in length for any one toothbrush, to reduce friction when the second bristles are applied to sensitive and/or inflamed buccal mucosa, which could cause pain to the user.

Preferably, the thickness of each second bristle 20 is between 0.02 and 0.50 mm, and most preferably between 0.05 and 0.12 mm.

The bristles of the third plurality of bristles 32, hereinafter referred to as the third bristles, may preferably be formed from polyamide 6,12, polyamide 11, polyamide 6,6, or a polyester such as polyethylene terephthalate. Polyamide 6,12 may be particularly preferred, for softness. The average spacing of the third bristles 32 is preferably between 0.15 and 4 mm, and most preferably between 0.5 and 2 mm. The preferred average length of the third bristles 32 would be between 1.5 and 2 cm, substantially longer than the first or second bristles 18, 20 to allow the third bristles 32 to be engaged with the user’s palate while the first bristles 18 are applied to the user’s teeth. Preferably, the thickness of each third bristle 32 is between 0.08 and 0.75 mm, and most preferably between 0.45 and 0.60 mm.

The tongue scraper 22, which, as shown in Figures 1 and 4, may preferably be located at the end, distal to the head 16, of the shaft 14, may preferably be integrally formed with the body 12 of the toothbrush 10. The tongue scraper 22 may be provided as a loop defining an aperture 34 therethrough, having a plurality of tongue engaging surfaces 36. The tongue engaging surfaces 36 preferably are substantially flat, but optionally may have surface texture features, such as the protrusions 38 shown. The surface texture features could also be dimples or ridges; beneficially, any such surface texture features may increase friction with the tongue in use and thus allow the tongue scraper to better remove tongue coating microflora.

In an alternative embodiment of a toothbrush in accordance with the invention, a toothpaste container may be at least in part formed by, or contained within, a portion of the shaft distal to the head. The toothbrush container preferably is in fluid communication with an aperture adjacent to or among one or more of the first plurality of bristles, the second plurality of bristles and the third plurality of bristles. In this case, the body of the toothbrush may preferably be formed from a flexible polymeric material, such as high-density polyethylene, to allow the toothpaste to be urged by a user from the toothbrush container to the aperture. In this context, the toothpaste container may advantageously be refillable or replaceable, although this would not be necessary if the toothbrush were to be provided as a disposable toothbrush, for dental demonstration purposes or hotel or spa use. A toothpick could also alternatively be provided at a portion of the shaft distal to the head of the toothbrush, or any one of a variety of dental accessories may be attachable to a mounting portion of the shaft distal to the head of the toothbrush.

The shaft may also optionally have a flexible portion proximal to the head of the toothbrush, including a haptic feedback device. The haptic feedback device may be provided as a hinge or other joint having an open and closed position, such that in the closed position of the haptic feedback device, the shaft and the head are in fixed alignment, whereas in the open position of the haptic feedback device, the shaft and the head are movable with respect to each other such that the toothbrush is rendered inoperable until the haptic feedback device is returned to the closed position.

When excessive pressure is applied to the user’s teeth with the toothbrush, the haptic feedback device may be forced into the open position. Preferably, the haptic feedback device may produce an audible signal, such as a clicking noise, on the transition from the closed to an open position, in order to alert the user immediately of the application of inappropriate pressure. As well as the haptic feedback provided by the movement of the haptic feedback device from the closed to the open position, the haptic feedback device may also temporarily vibrate once released into the open position.

A suitable location for the haptic feedback device is indicated by reference numeral 50 on Figure 1 of the drawings.

The toothbrush 10 hereinbefore described with reference to Figures 1 to 4 of the drawings is primarily intended for personal use by a user on their own teeth, but may also beneficially be used on another person’s teeth. For instance, the toothbrush 10 could be used in connection with the dental hygiene of a small child, or a person with disabilities, who is unable to brush their own teeth. Additionally, a dental professional may wish to demonstrate correct toothbrush technique to a patient, by brushing the said patient’s teeth using the toothbrush 10, while the toothbrush 10 is visible to the patient via a mirror system or otherwise.

In an exemplary method of use, a user applies toothpaste to the first bristles 18 of the toothbrush 10. For brushing of the mandibular anterior teeth, and the mandibular premolars and first and second molars, the toothbrush 10 is preferably first oriented with the shaft 14 approximately aligned with the superior-inferior axis across the mouth, with the head 16 aligned superior to the shaft 14, so that the first bristles 18 on the upper portion 16b of the head 16 can brush a coronal surface of each tooth, and the first bristles 18 on the lower portion 16a of the head 16 can brush a vestibular surface of each tooth. The toothbrush is then re-oriented, with the head 16 remaining in the mouth, so that the shaft 14 is approximately aligned with the posterior-anterior axis of the mouth, and the curvate upper portion of the head 16 is aligned inferior to the shaft 14. In such a position, the first bristles 18 on the upper portion of the head 16 can brush an oral surface of each tooth, while the first bristles 18 on the lower portion of the head 16 can brush a coronal surface of each tooth.

To brush the mandibular third molars, the toothbrush 10 may be oriented so that the shaft 14 is approximately aligned with the posterior-anterior axis of the mouth, and the curvate upper portion 16b of the head 16 is aligned approximately level with the shaft 14 in the superior-inferior axis. The first bristles 18 on the upper portion of the head 16 can brush a distal surface of each mandibular third molar in such a position, while the first bristles 18 on the lower portion 16a of the head 16 can brush a vestibular or oral surface of the mandibular third molar simultaneously; additionally or alternatively, with the curvate upper portion 16b of the head 16 aligned inferior to the shaft 14, the first bristles 18 on the lower portion of the head 16 can brush a coronal surface of the mandibular third molar simultaneously. While directly brushing a distal surface of a mandibular third molar is possible using a toothbrush as known in the art, the shaft of such a toothbrush must be oriented approximately perpendicular to the posterioranterior axis of the mouth, while approximately perpendicular to the superior-inferior axis of the mouth, which is typically uncomfortable for the user, as the shaft of the toothbrush must anteriorly displace an oral commissure so that the brush can contact a distal surface of a mandibular third molar.

This issue is not encountered with the toothbrush 10 of the present invention, due to the curvate nature of the head 16. Furthermore, during brushing of a distal surface of the mandibular third molar, the second bristles 20 advantageously may brush the buccal mucosa at or adjacent to a temporomandibular joint proximal to the mandibular third molar, and third bristles 32 beneficially may contact the gums.

To brush the maxillary third molars, the toothbrush 10 may also be oriented so that the shaft is approximately aligned with the posterior-anterior axis of the mouth, and the curvate upper portion 16b of the head 16 is aligned level with the shaft 14 in the superior-inferior axis. The first bristles 18 on the upper portion 16b of the head 16 can brush a distal surface of each maxillary third molar in such a position, while the first bristles 18 on the lower portion 16a of the head 16 can brush a vestibular or oral surface of the maxillary third molar simultaneously; additionally or alternatively, with the curvate upper portion 16b of the head 16 aligned superior to the shaft 14, the first bristles 18 on the lower portion 16a of the head 16 can brush a coronal surface of the maxillary third molar simultaneously.

For brushing of the maxillary anterior teeth, and the maxillary pre-molars and first and second molars, the toothbrush is preferably oriented with the shaft 14 approximately aligned with the posterior-anterior axis of the mouth, and the curvate upper portion 16b of the head 16 aligned superior to the shaft 14. In such a position, the first bristles 18 on the upper portion 16b of the head 16 can brush an oral surface of each tooth, while the first bristles 18 on the lower portion 16a of the head 16 can brush a coronal surface of each tooth.

To brush the vestibular surfaces of the maxillary teeth, the toothbrush 10 should be superiorly rotated between 35 and 65 degrees from the previous position, and most preferably 45 degrees, on the superior-anterior axis. In this position, the first bristles 18 on the upper portion 16b of the head 16 are not in contact with the user’s teeth, while the first bristles 18 on the lower portion 16a of the head 16 can brush a vestibular surface of each tooth. The toothbrush could conceivably be oriented with the shaft approximately aligned with the superior-inferior axis, to brush the vestibular surfaces of the maxillary teeth; however, in this position, the shaft of the toothbrush may be obstructed by the user’s nose, and the fully flexed wrist position required may be uncomfortable.

Throughout such an exemplary method, the second and third bristles 20, 32 of the toothbrush 10 may come into contact with the gums, buccal mucosa, palates, tonsils and/or uvula of the user, especially when the first bristles are passed between teeth. Additionally, subsequent to the brushing of the teeth, the user may apply the second and/or third bristles 20, 32, to the gums, buccal mucosa, palates, tonsils and/or uvula for complete buccal cleansing.

In one variation on the exemplary method of use hereinbefore described, a buccal gel, such as an analgesic gel, may be applied to the second and/or third bristles, to allow application of the buccal gel to a user’s, or another person’s, gums, buccal mucosa, palates, tonsils and/or uvula, especially in cases of inflammation or the presence of mouth ulcers.

It will be appreciated by the person skilled in the art that such an exemplary method of use as hereinbefore described is not limited to the first embodiment of a toothbrush in accordance with the invention, as illustrated in Figures 1 to 4, but may advantageously be applied to any toothbrush, and especially a manual toothbrush, having a curvate head.

Toothbrushes in accordance with the invention are not limited to manual toothbrushes. Referring to Figure 5 of the drawings, there is shown an electric toothbrush 110 in accordance with the invention. For features similar to those of the previous embodiment of the toothbrush described hereinbefore, further detailed description has been omitted for the sake of conciseness, and all elements previously described are indicated by their reference numeral in Figures 1 to 4 plus one hundred for ease of reference.

The head 116 of the toothbrush 110 has a hub 140 and a wheel 142 rotatably mounted therearound. The hub 140 may be preferably provided as a flat component with circular, or substantially circular cross-section, although polygonal shapes could also be considered. A first-plurality of bristles 118, comprising tooth bristles, may be located on the hub 140, projecting perpendicularly or substantially perpendicularly from a surface thereof. The hub 140 may be concentric to the wheel 142, but it could alternatively be substantially displaced from a centre of the wheel 142.

The wheel 142 may be level with the hub 140, preferably in a plane passing through the shaft 114 of the toothbrush 110. The wheel 142 may have a second plurality of bristles 120, comprising buccal cleansing bristles, projecting therefrom; the second plurality of bristles 120 may project perpendicularly or substantially perpendicularly from the surface of the wheel 142. The wheel 142 may be substantially flat, in which case the first plurality of bristles 118 may each be parallel to the second plurality of bristles 120. Alternatively, the wheel 142 may be curvate in a plane perpendicular to the shaft of the toothbrush 110, in which case the second plurality of bristles 120 may substantially cover the surface of the wheel 142.

While the second plurality of bristles 120 is shown projecting from the same side of the toothbrush 110 as the first plurality of bristles 118, they could also project from the other side of the toothbrush. The bristles 118, 120 may be formed of any material, and in any dimensions, hereinbefore described as advantageous with respect to the first embodiment of the toothbrush 10, with similar advantage.

The hub 140 and the wheel 142 may be coupled by at least one, and preferably a plurality of spokes 144. The spokes 144 may connect the hub 140 to an inner liner (not shown) of the wheel 142, which rotates commensurately to the hub 140. Likewise, the spokes could also connect the wheel to an outer liner of the hub, which rotates commensurately to the wheel. Either of these arrangements may result in the hub and the wheel being independently rotatable. However, the hub and the wheel may also be fixed by the spokes, such that they are not independently rotatable.

The wheel 142 may also be incommensurately rotatable with respect to the hub 140. In particular, the wheel 142 and the hub 140 may rotate in opposed angular directions, at the same or different angular speeds. Furthermore, while it is advantageous for the hub 140 to be rotatable around a full rotation, the rotation of the wheel 142 may be beneficially restricted to an angle deviation of between 30 and 180 degrees from the starting position.

Such a restriction may be particularly advantageous if the second plurality of bristles are non-uniformly disposed on the wheel, and especially if the second plurality of bristles project in a plane co-planar to the wheel, so that they are perpendicular or substantially perpendicular to the first plurality of bristles.

When the wheel 142 is independently rotatable with respect to the hub 140, the speed of rotation of the wheel 142 is preferably between 800 and 6000 rotations per minute. The speed of the rotation of the hub 140 may preferably be between 4000 and 18000 rotations per minute. The speed of rotation of the hub 140 and/or wheel 142 may be controllable by the user; this may be advantageous, as a predetermined speed of rotation for use on a healthy mouth may not be appropriate for a user with inflammation of the buccal mucosa.

If the wheel 142 is not independently rotatable with respect to the hub 140, a speed of rotation between 2000 and 6000 rotations per minute may be most appropriate, to compromise between the advantages of high speeds of rotation of the hub 140 for effective tooth brushing, and the risk of irritating the buccal mucosa or other mouth tissue with higher speeds of rotation of the wheel 142.

To allow rotation of the hub 140, and optionally the wheel 142, there may be provided a first motor (not shown), and an associated control circuit (not shown) operatively connected to the first motor, preferably enclosed, at least in part, within the body 112 of the toothbrush 110.

The first motor may be coupled to the head 116 of the toothbrush 110, such that the hub 140 of the head 116, and optionally the wheel 142, is rotatable by action of the first motor. The control circuit typically may be user-activated by means of a user activatable element such as a button 145, which preferably is implemented as a pushbutton with a catch which retains the button in place once it is sufficiently depressed, to prevent accidental deactivation of the toothbrush 110. User-activation by other means, such as a spoken command, processed via a voice-command recognition circuit, may also be considered.

Optionally, there may further be provided a second motor, preferably operatively coupled to the first control circuit and coupled to the wheel, to allow independent rotation of the wheel with respect to the hub. The second motor may be activated by the control circuit via the same button or other user-activation means. Alternatively, a dedicated control circuit and button or other user-activation means may be provided for the second motor, to allow the wheel to be rotated while the hub is stationary, and viceversa.

The toothbrush 110 may have a battery compartment (not shown) within its body, to receive and hold a battery to power the control circuit and one or more motors. Alternatively, the toothbrush may be connectable to an external power supply or mains voltage via a lead. An indicator light 146 may be provided on the body 112 of the toothbrush 110, to indicate to the user whether the toothbrush’s battery is adequately charged, or if the toothbrush is connected to an alternative power supply.

Each motor may beneficially be provided as a miniature DC motor, with diameter approximately 0.5 cm. The control circuit may control the motor speed by a conventional implementation of pulse width modulation, although other solutions in this regard would be evident to the person skilled in the art.

In use, the first plurality of bristles 118, on the rotating hub 140 of the head 116, may be placed into contact with vestibular, coronal and oral surfaces of each mandibular and maxillary tooth. Simultaneously, the rotating wheel 142 of the head 116 may contact the user’s gums, and/or buccal mucosa. The rotating wheel 142 may also advantageously allow brushing of the distal surfaces of the mandibular and maxillary third molars, particularly if it is possible to increase the speed of rotation of the wheel 142 for this purpose. The palates, tonsils and/or uvula may also be cleansed using the rotating wheel 142 of the head 16, especially if the rotation of the hub 140 of the head 116 is deactivatable.

Various other shapes of curvate head may be considered with respect to a toothbrush in accordance with the invention. In particular, a curvate head may be at least in part cylindrical, at least in part conical, frustoconical, substantially J- or U-shaped, or any other shape which is functionally equivalent to the curvate shapes herein described and illustrated.

It is therefore possible to provide a toothbrush having a curvate head, such that the distal surfaces of a mandibular or maxillary molar may be directly brushed, and a plurality of different types of brushes, to allow cleansing of the buccal mucosa and other mouth tissue, simultaneously or at different times to the brushing of the teeth. Advantageously, this may result in a reduced risk of tooth decay, and better general mouth hygiene, especially in the case of inflamed buccal mucosa.

The words ‘comprises/comprising’ and the words ‘having/including’ when used herein with reference to the present invention are used to specify the presence of stated features, integers, steps or components, but do not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, 5 described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination.

The embodiments described above are provided by way of examples only, and various other modifications will be apparent to persons skilled in the field without departing from the scope of the invention as defined herein.

Claims (21)

Claims

1. A toothbrush comprising: a body having a substantially straight elongate shaft and a head which is at least in part curvate with respect to the shaft, a first plurality of bristles projecting from the head, and a second plurality of bristles projecting from, or adjacent to, the head, the first plurality of bristles comprising a plurality of tooth bristles, and the second plurality of bristles comprising a plurality of buccal cleansing bristles, the second plurality of bristles being positioned at a different location to the first plurality of bristles, and projecting in a different direction relative to the first plurality of bristles.

2. A toothbrush as claimed in claim 1, wherein the head has a convex side and a concave side, and the first plurality of bristles projects from the concave side of the head.

3. A toothbrush as claimed in claim 2, wherein the second plurality of bristles projects from or adjacent to the convex side of the head.

4. A toothbrush as claimed in any one of the preceding claims, wherein the second plurality of bristles has a smaller average spacing between the bristles than the first plurality of bristles.

5. A toothbrush as claimed in claim 4, wherein the thickness of each bristle of the first plurality of bristles is in the range 0.15 mm to 0.35 mm, the average spacing of the first plurality of bristles is in the range 0.25 mm and 0.4 mm, and the average length of the first plurality of bristles is in the range 0.75 cm to 1 cm; and the thickness of each bristle of the second plurality of bristles is in the range 0.05 mm to 0.12 mm, the average spacing of the second plurality of bristles is in the range 0.025 mm to 0.2 mm, and the average length of the second plurality of bristles is in the range 0.35 cm to 0.5 cm.

6. A toothbrush as claimed in any one of the preceding claims, further comprising a third plurality of bristles projecting from and/or adjacent to the head, the third plurality of bristles comprising a plurality of buccal cleansing bristles.

7. A toothbrush as claimed in claim 6, wherein the third plurality of bristles projects at least in part from the shaft, proximal to the head.

8. A toothbrush as claimed in claim 6 or claim 7, wherein the third plurality of bristles has a larger average spacing between the bristles than the first plurality of bristles and/or the second plurality of bristles.

9. A toothbrush as claimed in claim 8, when dependent on claim 5, wherein the thickness of each bristle of the third plurality of bristles is in the range 0.45 mm to 0.60 mm, the average spacing of the third plurality of bristles is in the range 0.5 mm and 2 mm, and the average length of the third plurality of bristles is in the range 1.5 cm to 2 cm.

10. A toothbrush as claimed in any one of claims 6 to 9, wherein the third plurality of bristles project perpendicularly substantially perpendicularly to the first and second pluralities of bristles, the first and second pluralities of bristles projecting in opposite directions either side of the body, thereby providing a cruciform arrangement of bristles at or adjacent to the head.

11. A toothbrush as claimed in any one of claims 1 to 10, wherein the shaft has a flexible portion proximal to the head, and further comprising a haptic feedback device in the said flexible portion of the shaft.

12. A toothbrush as claimed in claim 1, wherein the head comprises a hub and a wheel rotatably mounted therearound.

13. A toothbrush as claimed in claim 12, wherein the hub is concentric to the wheel.

14. A toothbrush as claimed in claim 12 or claim 13, wherein the first plurality of bristles projects from the hub, and the second plurality of bristles projects from the wheel.

15. A toothbrush as claimed in any one of claims 12 to 14, wherein the hub and the wheel are coupled by a plurality of spokes projecting from the hub.

16. A toothbrush as claimed in any one of claims 12 to 15, further comprising a first motor and a control circuit operatively connected to the first motor, the first motor and the control circuit being enclosed at least in part within the body, the first motor being coupled to the head, and the control circuit being operable by a user-operable element to activate the first motor and thereby rotate the head.

17. A toothbrush as claimed in claim 16, wherein the motor is coupled to the wheel of the head, and further comprising a second motor coupled to the hub of the head, which is operatively connected to the control circuit and enclosed at least in part within the body such that the control circuit is operable by a useroperable element to activate the first motor and the second motor, to provide contrary motion of the wheel and the hub with respect to each other.

18. A toothbrush as claimed in claim 16 or claim 17, further comprising a useroperable button which is coupled to the control circuit to activate the first and/or second motor.

19. A toothbrush as claimed in any one of claims 12 to 18, further comprising a status indicator light on the body.

20. A toothbrush as claimed in any one of the preceding claims, further comprising a tongue scraper at an end of the body distal to the head.

21. A toothbrush as claimed in claim 20, wherein the tongue scraper is integrally formed with the shaft.