Abstract:
A disposable or edible chewable toothbrush is disclosed for cleaning teeth between meals. The device includes a chewable bristle holder with bristles attached to the holder, a cavity formed within the holder, a substance within the cavity, and regions of weakness formed in the holder that prevent leakage of the contents of the holder until the device is compressed by chewing. In another embodiment, a disposable or edible brush is housed inside within a disposable or edible shell. Upon chewing, the shell is broken or dissolves thereby releasing its contents, which include the brush and possibly a dentifrice.

Description:
BACKGROUND OF THE DISCLOSURE  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates in general to tooth cleaning devices, and particularly, to edible and/or disposable chewing utensils that clean teeth and freshen breath between meals or regularly scheduled tooth brushing sessions.  
         [0003]     2. Background Art  
         [0004]     Consumer tooth cleaning devices designed to help individuals control plaque buildup on teeth have existed for many years and in a variety of forms. The most basic technique for controlling plaque formation is through the use of hand-held, disposable toothbrush appliances, commonly known as toothbrushes. Other forms of mechanical tooth brushing devices include hand-held electrically driven toothbrush heads/bristles or ultrasonic tooth cleaning devices, and handle-free, chewable toothbrushing devices, such as that disclosed in U.S. Pat. No. 6,602,013 B2. Non-mechanical devices for tooth cleaning include chewing gum, fluoride rinses, and anti-bacterial mouthwashes. Because each of these tooth cleaning options has varying benefits and drawbacks, consumers must balance an array of variables when choosing one device over another, such as purchase costs, cleaning effectiveness, convenience of use, etc.  
         [0005]     Traditional hand-held toothbrushes purchased over-the-counter at retail outlets typically include an elongated handle formed from a thermoplastic, with nylon bristles securely embedded in rows at one end of the handle. A user of a traditional hand-held toothbrush typically applies toothpaste containing breath fresheners and fluoride, a known plaque inhibiter, to the bristles, and then gently scrubs the teeth with the bristles to mineralize the tooth enamel. For effective cleaning, a daily ritual of tooth brushing might include a session upon waking for the day and a session at the end of the day, with sparse opportunities, if any, throughout the day.  
         [0006]     More expensive variations of the traditional toothbrush include hand-held, electrically driven toothbrush heads/bristles and ultrasonic tooth cleaning devices. Electrically driven devices such as these generally provide better cleaning results than traditional toothbrushes, but the lack of portability together with high initial and recurring costs of these devices sometimes dissuade users from purchasing these products altogether.  
         [0007]     Significantly, however, traditional toothbrushes and the more modern electrically-driven devices suffer from a common shortcoming—they are impractical to use between meals throughout the day because they are too cumbersome, too costly, or rely on manipulation of a handle attached to the tooth brushing device to clean one&#39;s teeth and gums. Since consumers don&#39;t want to wait until the end of the day to have clean teeth and/or fresh smelling breath, consumers have resorted to more convenient but less effective options, such as chewing gum or rinsing with fluoride and/or anti-bacterial mouthwash formulations. Unfortunately, none of the non-mechanical alternatives provide the same level of tooth cleaning performance as compared to any of the hand-held mechanical tooth brushing devices. Therefore, it would be desirable to provide a mechanical, handle-less tooth brushing device having equivalent tooth cleaning and breath freshening characteristics as compared to traditional tooth brushing methods, and conveniently usable throughout the day between meals.  
         [0008]     Clark, U.S. Pat. No. 6,602,013 B2, discloses a handle-less, chewable toothbrush with omni-directionally positioned bristles affixed to a resilient bristle anchor. The bristle anchor is made of a deformable material that returns to its original shape when not being chewed. Inside the bristle anchor is a cavity usable for holding a substance, such as a dentifrice, which is released upon biting into the chewable toothbrush. However, Clark neither teaches nor suggests a handle-less chewable toothbrush having a brush unattached and floating inside a temporary shell.  
       SUMMARY OF THE INVENTION  
       [0009]     The present invention is directed to a toothbrush having a chewable shell formed from a resilient material and having an unstressed shape, the chewable shell being configured to compress upon itself in response to application of an external force, and return to the unstressed shape upon removal of the external force. The device further comprises a plurality of bristles attached to the chewable shell, a cavity formed within the chewable shell, a substance contained within the cavity, and a plurality of regions of weakness formed on the periphery of the chewable shell. The plurality of regions of weakness are operably configured to prevent leakage of the substance from inside the chewable shell before application of an external force, and configured to form a plurality of apertures through the chewable shell upon application of an external force to permit the substance to be released from within the cavity.  
         [0010]     The plurality of bristles on the toothbrush of the present invention may have a fixed end attached to the chewable shell and an unconstrained free end. The plurality of bristles may be formed from a resilient material or from a dissolvable or digestible material. Preferably, the plurality of bristles have round, square, or triangular cross sections and may have a textured surface.  
         [0011]     The substance contained in the cavity may comprise a dentifrice, and the cavity may also contain at least one shell stiffener. The at least one shell stiffener is preferably configured to follow the contour of the inner wall of the chewable shell.  
         [0012]     In another embodiment of the present invention, the toothbrush comprises a shell, a cavity formed within the shell, and a brush comprising a plurality of bristles. The brush is operably configured to be contained within the cavity and the shell is configured to expose the brush upon application of an external force to the shell.  
         [0013]     The cavity may contain a substance that is configured to become exposed upon application of the external force to the shell. Preferably, the substance comprises a dentifrice or a flavored breath freshener.  
         [0014]     In an embodiment of the invention, the brush further includes a bristle holder, which is operably configured to apply a compressive force to the plurality of bristles to restrain each of the plurality of bristles with respect to one another. Preferably, the bristle holder comprises a coil compression spring, itself preferably comprising an edible material.  
         [0015]     In an embodiment of the invention where each of the plurality of bristles have at least one end, the brush further includes a substantially incompressible core of cylindrical, spherical, ellipsoid, or rectangular shape for securely mounting one end of each of the plurality of bristles to form the brush. Preferably, the bristle core comprises an edible material.  
         [0016]     In an embodiment of the invention, the shell is disposable. Alternatively, the shell may be made from an edible material capable of dissolving in one&#39;s mouth. Preferably, the edible material comprises cellulose or gelatin.  
         [0017]     In an embodiment of the invention, the brush is made from an edible material. Preferably, the edible material comprises cellulose.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]      FIG. 1  is a perspective view of a chewable toothbrush according to one embodiment of the invention.  
         [0019]      FIG. 2  is a perspective view of the chewable toothbrush according to the embodiment of  FIG. 1 , in partially collapsed form and showing optional contents of the device expelled or emitted therefrom.  
         [0020]      FIG. 3  is a detail perspective view of the chewable toothbrush of  FIG. 1  showing areas or points of weakness in a shell.  
         [0021]      FIG. 4  is a detail perspective view of the chewable toothbrush of  FIG. 1  in partially collapsed form and showing the contents of the device being expelled from the areas or points of weakness in the shell.  
         [0022]      FIG. 5  is another perspective view, shown in partial section, of the chewable toothbrush of  FIG. 1  and showing interior shell stiffening structures.  
         [0023]      FIG. 6  is a yet another perspective view, shown in partial section, of the chewable toothbrush of  FIG. 1  in partially collapsed form and showing interior shell stiffening structures.  
         [0024]      FIG. 7  is a perspective view, shown in partial section, of the chewable toothbrush of  FIG. 1  showing an alternate form of interior shell stiffening structures.  
         [0025]      FIG. 8  is a perspective view, shown in partial section, of the chewable toothbrush of  FIG. 1  in partially collapsed form and showing the alternate shell stiffening structures of  FIG. 7 .  
         [0026]      FIG. 9  is a perspective view of another embodiment of a chewable toothbrush with the brush floating inside a shell.  
         [0027]      FIG. 10  is a cutaway perspective view of the chewable toothbrush of  FIG. 9  showing the contents inside the shell.  
         [0028]      FIG. 11  is a side view of the chewable toothbrush of  FIG. 9 .  
         [0029]      FIG. 12  is an end view of the chewable toothbrush of  FIG. 9 .  
         [0030]      FIG. 13  is a perspective view of the brush of the chewable toothbrush of  FIG. 9 .  
         [0031]      FIG. 14  is a perspective view of the bristle holder, in partial extension, of the brush of  FIG. 13 .  
         [0032]      FIG. 15  is a perspective view partially showing the brush of  FIG. 13 , and additionally showing a cylindrical bristle core.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0033]     While this invention is susceptible of embodiment in many different forms, there are shown in the drawings and will herein be described in detail, certain preferred embodiments with the understanding that the present disclosure should be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiments so illustrated.  
         [0034]      FIGS. 1-8  describe a chewable toothbrush according to one embodiment of the invention. Chewable toothbrush  10 , as illustrated in  FIG. 1 , is generally spherical in shape in its unstressed state and includes bristles  12  for massaging gums and cleaning crevices in and around teeth. Bristles  12  originate from, and are embedded in, shell  14  (see also  FIGS. 3-4 ) via an interference fit.  
         [0035]     In a disposable configuration, bristles  12  may be made from any resilient, food-grade material (such as nylon, vulcanized rubber, etc.) to enable the bristles to reach deep inside tooth and gum crevices, yet are pliable enough to bend or “give” under ordinary chewing forces and return to their original shape when not under load. Alternatively, bristles  12  may be made from an edible material, such as cellulose that dissolves over time when warmed, chewed, or wetted by the mouth.  FIGS. 1-8  show bristles  12  as having a round cross-section, uniform texture, uniform thickness, and uniform length, however, bristles  12  may instead be manufactured in a variety of cross sectional shapes, textures, lengths, and thicknesses, or combination thereof, to achieve optimum tooth cleaning performance. Bristles  12  are preferably manufactured with diameters of about 0.001 to about 0.05 inches and lengths of about 0.25 to about 0.5 inches. And while individual bristles  12  are shown uniformly positioned around spherical shell  14 , they may instead be positioned non-uniformly around shell  14 , possibly even in random patterns or groups. Individual bristles of small diameter may also be bundled with other individual bristles to form groups of individual bristles that are secured at a single attachment point in shell  14 . Thus, each individual bristle shown in  FIGS. 1-8  may actually comprise bundles of individual bristles. In addition, bristles  12  and shell  14 , collectively, may be formed from a single, homogenous piece such that bristles  12  extend from shell  14  without any mechanical attachment means.  
         [0036]     As shown in  FIGS. 1-8 , shell  14  is generally spherical in shape and is designed to securely retain bristles  12  to shell  14  using common techniques typical in the toothbrush manufacturing industry. Under normal chewing forces, shell  14  may temporarily collapse or deform (see  FIGS. 4, 6 , and  8 ), but may be prompted by material properties or internal supports to return to its original shape when the consumer is not biting down on chewable toothbrush  10 . Shell  14  is preferably made of a resilient, food-grade material, such as vulcanized rubber, silicone rubber, etc. Shell  14  may alternatively be manufactured from an edible (i.e., digestible) food product that, when dry, is substantially rigid and inflexible, but may become more flexible and pliable when wet and/or warmed by a mouth, or may even dissolve altogether. Cellulose and gelatin are representative examples of dissolvable shell materials.  
         [0037]     Shell  14  may be manufactured in a variety of thicknesses and outer diameters, ranging from about 0.002 to about 0.025 inches thick and about 0.25 to about 1.0 inches in diameter, depending on the market being served. For example, if the target market is teenage children whose mouths are smaller than those of grown adults, the diameter and thickness of shell  14  and/or length of bristles  12  can be decreased to enable more comfortable chewing. Likewise, if the target market is adults, then the diameter and thickness of shell  14  and/or length of bristles  12  can be increased to achieve more effective performance for adult teeth and gums.  
         [0038]     Inside shell  14  is void  16  (see  FIGS. 5-8 ) that can optionally accommodate any number of substances  18  to help clean and/or whitening teeth, or to freshen one&#39;s breath. By way of example without intending to limit the types of substances that may be present, void  16  may contain fluoride toothpaste, whitening toothpaste, a flavored fluoride or non-fluoride rinse, an anti-bacterial mouthwash, a sugared or sugarless flavoring, or simply a breath freshener. Any substance  18  that is placed inside shell  14  in void  16  is permitted to escape into one&#39;s mouth during chewing, as illustrated in  FIGS. 2 and 4 , when shell  14  ruptures at one or more areas or points of weakness  20  fabricated in the outer surface of shell  14 , as shown in  FIGS. 1-4 . Areas or points of weakness  20  preferably do not extend through the thickness of shell  14 . Substance  18  may include a formulation intended either to be swallowed or expelled.  
         [0039]      FIGS. 5-6  show at least one optional shell wall spring stiffener  22 ,  23  inside shell  14  in void  16 . Spring stiffener  22 ,  23  is usable to assist shell  14 , if necessary, in maintaining the shell&#39;s original unstressed shape for long term chewing of chewable toothbrush  10 . Under normal chewing forces, shell  14  will temporarily collapse or deform, as will spring stiffener  22 ,  23 , but each will return to its original shape when the consumer is not biting down on chewable toothbrush  10 . Spring stiffener  22 ,  23  is made from a resilient material that is optionally affixed to the inner wall  24  of shell  14  at each end of spring stiffener  22 ,  23 .  
         [0040]      FIGS. 7-8  show at least one optional spring stiffener  26 ,  27  illustrated in yet another alternative configuration. Rather than being attached to inner wall  24  in void  16  of shell  14 , spring stiffener  26 ,  27  is formed in the shape of a continuous hoop closely matching the contour of inner wall  24 . In this configuration, if more than one spring stiffener is employed, one will nest inside another. Spring stiffeners  22 ,  23 ,  26 , and  27  are shown in  FIGS. 5-8  as being relatively flat to enhance their ability to nest one inside the other without undue deflection as each passes by the other in the center of void  16  ( FIGS. 5-6 ) or at the inner wall  24  of void  16  ( FIGS. 7-8 ). However, spring stiffeners  22 ,  23 ,  26 , and  27  need not be constrained to any one particular configuration so long as their intended function of assisting shell  14  in maintaining the shell&#39;s original shape is not impeded. Any number or combination of spring stiffeners  22 ,  23 ,  26 , and  27  may be employed.  
         [0041]     Use of chewable toothbrush  10  between meals according to the present invention begins by placing a single chewable toothbrush  10  in one&#39;s mouth and chewing like ordinary chewing gum. Bristles  12 , as shown and described above, behave like ordinary hand-held toothbrush bristles such that one&#39;s chewing and sloshing movements of chewable toothbrush  10  within one&#39;s mouth gently scrubs teeth and gums clean of food and plaque. Apertures  21  form in shell  14  when areas or points of weakness  20  split open during chewing of chewable toothbrush  10 . If present, substance  18  is released from void  16  through apertures  21  in shell  14  to further one&#39;s enjoyment and/or enhance the cleaning effectiveness of chewable toothbrush  10  during chewing. The size and shape of apertures  21  may control the rate of release of substance  18  from void  16 . For example, smaller openings may permit a slower rate of release of substance  18  while larger openings may permit a higher rate of release. Actual rates of release depend on the density and viscosity of substance  18  and the size of apertures  21 .  
         [0042]     When chewing is no longer desired, the user may simply dispose of chewable toothbrush  10 , or alternatively, may save it for reuse at a later time. It should be noted that for chewable toothbrush  10  to function as described, shell  14  need not be spherical in shape but instead may optionally be formed in the shape of figurines or other geometric shapes, for example. In addition, chewable toothbrush  10 , including shell  14 , bristles  12 , and any present shell spring stiffener  22 ,  23 ,  26  or  27  may optionally be fabricated from materials that slowly dissolve upon insertion into one&#39;s mouth. In this way, nothing need be expelled from one&#39;s mouth.  
         [0043]     In another embodiment of the invention (not shown), substance  18  may instead cover the outside of shell  14  to partially or completely immerse bristles  12 . In this configuration, shell  14  need not be hollow inside.  
         [0044]     In another embodiment (not shown), shell  14  may be formed from an absorbent sponge-like material useful for helping a user expel, rather than swallow, substance  18  by reabsorbing substance  18  after a user is done chewing toothbrush  10 .  
         [0045]     In another embodiment (not shown), a plurality of blisters containing substance  18  may be formed sporadically on the outer surface (in and around bristles  12 ). Upon chewing, the blisters would break open (or dissolve) to release substance  18 . Shell  14  need not be hollow in this configuration.  
         [0046]     Another embodiment of the invention is illustrated in  FIGS. 9-15 . Chewable toothbrush  40  is shown as being generally ellipsoid in shape. In this embodiment, brush  42  is located entirely inside, and unattached to, shell  44  in void  46  rather than having bristles  43  affixed to shell  44 . Shell  44  may be made from a relatively hard or relatively soft and/or compressible material, but preferably an edible material that dissolves or breaks open when chewed, wetted or warmed by the mouth. However, shell  44  may also be made from a non-edible, disposable material that readily breaks open, exposing its contents, when bitten into. As before, void  46  in shell  44  may optionally contain any number of substances  50  to help clean and/or whiten teeth, or to freshen one&#39;s breath. By way of example without intending to limit the types of substances that may optionally be present, void  46  may contain fluoride toothpaste, whitening toothpaste, a flavored fluoride or nonfluoride rinse, an anti-bacterial mouthwash, a sugared or sugarless flavoring, or simply a breath freshener. Any substance  50  that is placed inside shell  44  in void  46  is permitted to escape into one&#39;s mouth during chewing because shell  44  is made to readily dissolve and/or break open during chewing. Substance  50  may consist of a formulation intended either to be swallowed or expelled.  
         [0047]     While shell  44  in  FIGS. 9-12  is shown as being ellipsoid, as before, shell  44  may optionally be formed in any shape to enclose brush  42 . Likewise, brush  42  can be manufactured in any shape so long as it can be carried within the volume dictated by the chosen shape of shell  44 . Alternatively, a liquefied substance that solidifies at room temperature, such as a sugar-free candy, may be poured into a mold containing brush  42  and allowed to harden so that brush  42  is completely submerged within a solid mass. During use, the candy may dissolve or break up during chewing leaving brush  42  that can be chewed. Shell  44  of  FIGS. 9-12  is preferably made from a material that will dissolve in one&#39;s mouth during chewing, such as gelatin or cellulose. Alternatively, shell  44  need not be present at all if substance  50  comprises a hardenable, dissolvable, edible material in sufficient quantity to either partially or completely envelop brush  42 . In this way, substance  50  may dissolve or be broken apart during chewing leaving brush  42  in one&#39;s mouth to clean one&#39;s teeth. Brush  42  may also be manufactured from a dissolvable material having a different dissolution rate than that of substance  50  so no part of chewable toothbrush  40  need be discarded.  
         [0048]     As shown in  FIGS. 9-15 , individual bristles  43  of brush  42  pass through a spring-like holder  48  as a means of securing individual bristles together. Coils  49  of holder  48  (see  FIG. 14 , with coils shown in partial extension) are preferably in compression so as to apply a compressive force on bristles  43  to hold the bristles in place. Individual bristles  43  are nested one next to the other and individually may vary in length from about 0.25 to about 1.0 inches. The outer diameter  52  of holder  48  may be sized in tandem with the length of the bristles to help prevent bristles  43  from bending excessively during chewing, thereby permitting bristles  43  to penetrate deep inside tooth crevices and gingiva. Alternatively, as partially shown in  FIG. 15 , bristles  43  may be embedded in, and originate from, a solid cylindrical, spherical, or rectangular bristle core to form brush  42 , with bristles  43  being fed between coils  49  of holder  48 . Bristle core  54  of this design could be used instead of holder  48 , or in combination with holder  48 , to firmly constrain bristles  43 . Bristles  43  are shown in  FIGS. 9-14  as having a round cross section, uniform texture, and uniform thickness, however, bristles  12  may instead be manufactured in a variety of cross sectional shapes, textures, lengths, and thicknesses, or combination thereof, to enable efficient packaging within shell  44  and to achieve optimum tooth cleaning performance. Bristles  12  are preferably manufactured with diameters of about 0.001 to about 0.05 inches.  
         [0049]     The foregoing description and drawings merely explain and illustrate the invention, and the invention is not so limited as those skilled in the art who have the disclosure before them will be able to make modifications and variations therein without departing from the scope of the invention.