# Patent

## Title
Toothbrush with visual and/or other sensory effects

## Abstract

Toothbrushes comprising components with light transmitting and structural characteristics provide enhanced visual and other sensory effects. The components in combination are generally chemically compatible and function to provide areas of varying visibility of features. At least one of the components may include a scenting agent.

## Background
CROSS-REFERENCE TO RELATED APPLICATIONS
The present invention is a continuation of U.S. application Ser. No. 12/142,900 filed on Jun. 20, 2008, now U.S. Pat. No. 8,510,893, the entirety of which is hereby incorporated by reference.


BACKGROUND OF THE INVENTION
The present invention relates to multi-component toothbrushes having enhanced visual and/or scenting effects resulting from the properties (e.g., transparency) and structural configuration (e.g., use of a base component having projections) of the toothbrush components.
Toothbrushes are often constructed from multiple components having dissimilar properties in terms of hardness, texture, color, etc. to provide an overall product possessing a number of desired features, such as ease of gripping, good bending/flexibility characteristics, and high durability. However, the domain of possible combinations of components which can be combined using straightforward manufacturing techniques is limited by component compatibility, which in turn depends upon the individual component compositions. Thus, while the incorporation of aesthetic features (e.g., three-dimensional effects) and even scenting agents in toothbrushes may be desired to improve product appeal to the user, the components required to obtain these properties often cannot be easily combined in an efficient and/or low-cost manner. For example, combining transparent and opaque plastics can require the use of chemical adhesives or bonding agents for acceptable adherence of these components.
BRIEF SUMMARY OF THE INVENTION
Aspects of the invention relate to toothbrushes constructed of at least two components such as injection molded plastics having distinct optical properties (e.g., transparency). In representative embodiments, the components are chemically compatible such that they can be acceptably adhered to one other without an adhesive.
The components combine to provide visual effects such as the appearance of three-dimensional features (e.g., projections) in a base component at varying depths beneath an overlying (or covering) transparent or partially transparent second component. For example, if the second component is only partially transparent, then its use to cover projection surfaces of a base component at varying thicknesses will result in varying degrees of visibility of these surfaces. Projection surfaces covered by a relatively thick layer of partially transparent plastic component may be only faintly visible compared to projection surfaces covered by a relatively thin layer (or otherwise not covered at all, i.e., protruding through the partially transparent plastic component). If desired, underlying surfaces of the base component may be essentially completely obscured, causing the projection surfaces to appear suspended in the partially transparent second component.
In some embodiments, the second components or other toothbrush components may contain scenting agents. In any event, it will be appreciated from the present disclosure how varying component thicknesses and scenting concentrations can be used to vary and control the release of scenting agent from different portions of the toothbrush surface exterior (e.g., portions of the handle).
Aspects of the invention therefore relate to a toothbrush comprising a base component comprising an outer surface, a gripping region and an oral engaging region; a second component covering at least a portion of said base component in said gripping region, wherein said base component comprises a plurality of cutouts and at least one projection in said gripping region, wherein said first component is opaque and said second component is at least partially transparent, wherein said at least one projection is oval in shape and protrudes through said second component so that a surface of said at least one projection is substantially flush with said outer surface of said base component.
Further aspects of the invention relate to a toothbrush, as discussed above, comprising a base component having a gripping region and an oral engaging region and a second component covering a portion of the base component in the gripping region. The base component and the second component are chemically compatible, such that the components can adhere to a satisfactory degree without the use of a chemical adhesive, bonding agent, or even mechanical interlocking of the components.
These and other aspects of the invention will become apparent from the following Detailed Description.



BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the present invention and the advantages thereof may be acquired by referring to the following description in consideration of the features depicted in accompanying drawings, which should be understood to present an illustration of the invention and/or principles involved, and in which like reference numbers indicate like features, and wherein:
FIG. 1 is a front view of a base component of a toothbrush according to one or more aspects of an illustrative embodiment;
FIG. 2 is a side view of a base component of FIG. 1;
FIG. 3 is a rear view of a base component of FIG. 1;
FIG. 4 is a front view of a toothbrush according to one or more aspects of an illustrative embodiment; and
FIG. 5 is a simplified cross-sectional view, taken across section 5-5, of the handle of the toothbrush of FIG. 4.



DETAILED DESCRIPTION OF THE INVENTION
Aspects of the invention relate to multi-component toothbrushes having a number of distinct commercial advantages resulting not only from the types of materials used in the components but also from structural features, light transmitting properties, and other properties of these components. The combination of properties of the individual components advantageously provides appealing sensory effects that may include both visual effects and/or scenting (olfactory) effects. According to some embodiments, features such as three-dimensional structures in a base component of the toothbrush can be displayed through a transparent or semi-transparent second component. Varying the depth at which the features of the base component are covered by the second component consequently varies the degree to which the features are visible to the user. Similarly, if the base component incorporates a scenting agent, then the rate of diffusion of this agent to the exterior of the toothbrush (and ultimately to the user) may also be controlled by variation of the depth of coverage by the second component.
In this manner, one or more sensory effects (e.g., visual or olfactory) or characteristics of the toothbrush can be readily controlled by selecting a number of appropriate parameters (e.g., degree of transparency of the components, depth of coverage of one component over another, scenting agent concentrations of the components, etc.). Aspects of the invention are therefore directed to toothbrushes having exterior portions (e.g., portions of the handle) with more than one degree of visibility of structural features and/or more than one rate of scent release. These characteristics result when toothbrush components have properties and are combined as described herein.
Toothbrushes according to the invention are formed from combining at least two components having different optical properties (e.g., transparency). Materials suitable for the components of the toothbrushes include polymeric materials such as those which can be injection molded. In a representative embodiment, two components that are contacted to form the toothbrush, or at least form part of the toothbrush where visual features such as projections of a base component are displayed through a transparent or semi-transparent second component, both comprise a polyolefin (e.g., polyethylene such as high density polyethylene, polypropylene, a polyolefin blend such as an ethylene-propylene blend, or an olefin copolymer such as a random ethylene-propylene copolymer).
The use of two components comprising or even consisting essentially of polyolefins provides important advantages in terms of the chemical compatibility of the components. Components that are “chemically compatible,” such as those that are both members of the olefin family, can adhere without the aid of a separate adhesive layer or bonding agent. Chemically compatible components may also be joined in a satisfactory manner without relatively complex mechanical interlocking that is sometimes employed between toothbrush components that are not chemically compatible (e.g., comprise dissimilar materials, as in the case of one component comprising predominantly a polyolefin and a second component comprising predominantly a non-polyolefin such as polystyrene, polycarbonate, or styrene-acrylonitrile).
Therefore, according to some embodiments, components of multi-component toothbrushes of the invention lack an adhesive, a bonding agent, or the use of mechanical interlocking between components. According to other embodiments, adhesive, bonding agent, and/or mechanical interlocking may be used even with the chemically compatible components, to achieve a relatively stronger and more durable bond between the components than would be achieved using components that are not chemically compatible. In still other embodiments, a relatively lower amount of adhesive or bonding agent, and/or a relatively lower degree of mechanical interlocking, may be used to achieve a bond between the chemically compatible components that is comparable in strength and integrity to that between two components that are not chemically compatible.
In view of the above description, it is apparent that joining chemically compatible components (e.g., both comprising predominantly polyolefins), according to aspects of the invention, simplifies the manufacture of toothbrushes to reduce costs and provide other distinct advantages. Such advantages include greater ease of processing (e.g., elimination or reduction of a pre-molding drying step). In the case of two components that both comprise polyolefins, advantages include retention of physical strength in the normal oral care use environment (due to chemical inertness of these components) and reduced material cost.
FIGS. 1-3 depict various views of one component, referred to herein as a first or a base component 10, used in a representative toothbrush of the invention. Base component 10, as depicted, can provide the main structure of the toothbrush and consequently the main source of some of the overall toothbrush properties such as strength, flexibility/rigidity, etc. Base component 10 may be formed from a polyolefin such as polypropylene, as discussed above, into its desired shape by injection molding.
Base component 10, may comprise one or more gripping regions (references 12 in FIG. 2) or regions that are normally gripped or held by the user. Base component 10 may also comprise an oral engaging region 14 or region that is normally fabricated with cleaning elements such as bristle tufts that are applied to the user's teeth. A neck 16 may separate and extend between these regions and, according to FIG. 2, may provide a two-segmented structure with a front segment comprising gripping regions 12 and a rear segment comprising oral engaging region 14, with the front segment being inclined or angled relative to (i.e., not collinear with) the rear segment. For example, the front segment may be inclined (i.e., offset from the formation of a straight line) at an angle from about 5° to about 40° relative to the rear segment.
As may be best seen in FIG. 2, base component 10 includes projections 15 that form a three-dimensional decorative design. Projections 15 are shown in FIG. 2 protruding from an underlying surface 20, in gripping region 12 of base component 10. It will be appreciated that projections could be formed in other locations of base component 10, and that “projections” may refer to any of a number of features extending or protruding from base component 10, such as the simple columns shown in FIGS. 1 and 2, the lettering best shown in FIG. 1, or features having other horizontal cross-sectional shapes such as circles, ovals, stars, hearts, cartoon characters, etc., which may be projected through a second component of a transparent or semi-transparent material to provide a visually appealing effect. Furthermore, it is to be understood that the three-dimensional decorative design in the base component 10 may be created by cutouts in the underlying surface 20, rather than by protrusions from the underlying surface 20, so long as the projections 15 are formed.
According to some embodiments, projections 15 may provide visual effects that improve brand recognition and/or help associate the toothbrush with related products (e.g., toothpaste) bearing similar visual features and possibly being packaged together. For example, white square or rectangular projection surfaces 18 in a gripping region of base component 10, as shown in FIG. 1, may have an appearance that is similar to solid pieces of soluble breath-freshening agent that are visibly suspended in a packaged toothpaste.
As shown in FIG. 2, projections 15 may extend or protrude from underlying surface 20 of base component 10 at more than one height and/or be visible to different degrees through a second component overlying or covering these projections at varying thicknesses. As discussed in greater detail below, at least one, and possibly several or more, of a plurality of projections 15 extending from base component 10 may protrude entirely through a second component.
Projections 15 that protrude at different heights therefore may provide projection surfaces 18a, 18b, 18c at various levels above underlying surface 20, directly beneath projections 15 of base component 10. For example, projection surfaces 18a, 18b, 18c may be at a first, a second, and a third height above underlying surface 20, where two or all three of these heights are different. A second component could therefore easily be applied over projections 15 and all adjacent, surrounding underlying surfaces 20, for example in a gripping region 12 of base component 10, to cover base component 10 at varying thicknesses in this region.
In this manner, underlying surface 20 may be covered with a substantially uniform first thickness of a second component, while projection surfaces 18a, 18b, 18c may be covered with second, third, and/or fourth thickness of the second component. The second, third, and fourth thicknesses can differ from the first thickness and possibly also differ with respect to each other. Thus, the second, third, and fourth thicknesses may be substantially the same or all substantially different, or only some thicknesses may be substantially the same with respect to others, depending on the desired visual effect. If the overlying second component is partially transparent, then its use to cover projection surfaces of the base component at substantially the same thickness will result in substantially the same degree of visibility of these projection surfaces through the second component.
In a representative embodiment depicted in FIG. 2, first and second projection surfaces 18a, 18b (e.g., at different heights above underlying surface 20) are covered with a second, semi-transparent component at second and third thicknesses that are different, while adjacent, underlying surface 20 is covered at a first thickness that is different from both of the second and third thicknesses. Thus, for example, projection surface 18b, which is at a greater height above underlying surface 20 than projection surface 18a, may be covered by a relatively smaller thickness of a semi-transparent second component, to provide a more clearly visible projection surface 18b and a more faintly visible (or more obscured) projection surface 18a. Projection surfaces may have any shape, as discussed above with regard to the cross-sectional shapes of projections. Projection surfaces typically have areas that project appealing features including squares or rectangles of about 1-10 mm2 in area. Projection surfaces may have larger or even smaller areas, such as in the case of one or more projections that taper essentially to points, creating a visual image in the form of a small dot or dots.
As mentioned above, according to some embodiments, the thickness of a second component covering a projection surface may be zero, such that a projection surface (or a portion of a plurality of projection surfaces) may protrude entirely through the second component. Such an embodiment is depicted for a representative toothbrush in FIG. 4 and a simplified cross-section of this toothbrush in a gripping region is depicted in FIG. 5. As shown in these figures, projection surfaces 18b protrude through second component 40 that covers a portion of a gripping region. These projection surfaces 18b, covered with second component 40 at a third thickness that is zero, are therefore completely visible. Other projection surfaces 18a, however, are covered with second component 40 at a second thickness that may be, for example, about 2 mm, while the adjacent underlying surface is covered at a first thickness, for example, about 4 mm, that is different from both the second and the third thicknesses.
As shown in FIG. 5, projection surfaces 18b protruding through second component 40 are essentially flush with the surface of second component 40, such that projections 15 and second component 40 cooperate to form a smooth or essentially smooth exterior in areas where the second component is present, such as in the handle or other portions of the gripping area. According to other embodiments, exposed projection surfaces 18b may extend above the surface of the second component 40 or be recessed below this surface.
In the embodiment of FIGS. 4 and 5, therefore, underlying surface 20 (covered at a first thickness) of base component 10 will be more obscured (or less visible) than some projections surfaces 18a (covered at a second thickness), which are in turn more obscured than other projection surfaces 18b (covered at a third thickness, which is zero in the case of FIGS. 4 and 5). By adjusting the transparency of overlying second component 40, it may be possible to almost completely or completely obscure underlying surface 20 (rendering it substantially invisible) and also provide a distinct difference between the relative visibilities of projection surfaces 18a, 18b covered at different thicknesses. This may have a desired effect, for example, of simulating objects that are “submerged” to various degrees in a semi-transparent second component. Additional projection surfaces, for example, in the form of lettering (see FIG. 1) may be covered with the second component at a thickness that substantially matches any of the first, second, or third thickness, or otherwise covered at another, different thickness.
The second component, according to aspects of the invention, covers the base component at more than one thickness to provide sensory effects such as the visual effects discussed above. Usually, the base component of the toothbrush is covered only in one or more areas (such as at least a portion of the handle or gripping region but often not the entire handle) where the sensory effects are desired. In other regions that are not covered, therefore, the thickness of the second component can be considered to be zero. According to the description above, then, the second component can be said to cover the base component (which includes its projection surface(s) and its underlying surface) at more than two different thicknesses, or more than one non-zero thicknesses having discreet values (e.g., about 2 mm and about 4 mm) to provide the visual effects described herein. According to some embodiments, the second component will cover the base component, for example in a portion of the gripping region, at a maximum thickness of about 8 mm, and typically about 5 mm.
In desired areas, such as a portion of the handle or gripping region, where the second component is used to cover the base component, the second component may be injection overmolded. As discussed above, the second component is used to cover projection surfaces formed from projections in the base component, as well as adjacent underlying surfaces. These projection surfaces may be formed on any part, including recessed areas, of the base component, onto which the second component is desirably overmolded. It will be appreciated that the base component, used to form projections, may be, but is not necessarily, the innermost component of the toothbrush. For example, the base component may be disposed upon an inner core component, such that the base component is actually between the core component and the second component. The main consideration is that the visual effects discussed above can be achieved, and various combinations of components for this purpose will be become apparent to one of skill in the art, having regard for the present disclosure.
As discussed above, the second component is advantageously chemically compatible with the base component, to provide favorable adherence/bonding between these components. Thus, if the base component comprises a polyolefin, then the second component may be, for example, polypropylene or a random ethylene-propylene copolymer. To provide the visual effects described above, in which features of the base component are visible to varying degrees through the second component, the base component and second component may have different transparencies. For example, the base component may be essentially opaque (e.g., have an opaque white color or other opaque color) while the second component may be at least semi-transparent (e.g., have a semi-transparent blue color). Semi-transparency or full clarity can be achieved, for example, by modification of the second component with a clarifying agent, with the degree of transparency depending on the concentration of clarifying agent.
The extent of clarification or transparency of the second component will govern the degree to which projections (e.g., columns, a product logo, or other features) in the base component are visible through various thicknesses of the second component. In a representative embodiment, good visual effects are obtained when the second component has a maximum haze value of about 20% (e.g., from about 5% to about 20%) at a thickness of 2 mm and a maximum haze value of about 45% (e.g., from about 25% to about 45%) at a thickness of about 3 mm. The haze value may be measured according to ASTM D-1003 for transparent parts. The clarified second component may be used with its natural color or may be tinted with coloring agents known in the art, including soluble colorants such as Milliken Clear Tint® (Milliken Chemical, Spartanburg, S.C.).
Advantageously, other sensory effects of the overall toothbrush may be incorporated and controlled in a manner similar to that discussed above with respect to the visibility of projections of the base component (e.g., by varying the thickness of the overlying second component and/or the transparency of the second component relative to the base component). In the case of a smell (scenting or olfactory) effect, for example, the scenting of polymeric materials and particularly polyolefins may be accomplished by blending a scenting agent, optionally together with a carrier, directly into these materials prior to injection molding.
Scenting agents for polymeric materials include aromatic oils and other liquids that are slowly released, as described, for example, in U.S. Pat. No. 6,334,974. Carrier materials that are blended with scenting agents include polymers such as polyolefins (e.g., polyethylene) and ethylene vinyl acetate copolymer. Scenting compositions, comprising both a scenting agent and a carrier, may be used in preparing scented plastics having a wide range of possible scents or fragrances, including vanilla and mint. Examples of such compositions include those available under the PolyIFF® brand from International Flavors and Fragrances, Inc (New York, N.Y.). Combinations of scenting agents can also be used.
Those skilled in the art can readily determine the types of scenting agent carrier that are compatible with component materials used in the toothbrush. Generally, the scenting agent, if used, is incorporated as a scenting composition with a carrier into a component such as the base component in an amount such that the characteristics of the base component are not substantially altered. Thus, a base component comprising predominantly a polyolefin such as opaque white polyethylene may be impregnated with a scenting agent in an amount such that the desired properties and characteristics of the base component (e.g., color, adhesion/bonding to other polyolefin-containing components, ability to be processed, strength, etc.) are substantially retained.
Typical weight ratios of scenting composition (i.e., combined scenting agent and carrier) to base component or other component (e.g., the second component) range from about 1:20 to about 1:5, and often from about 1:19 to about 1:9. The amount of scenting agent added will depend on the desired strength of the scent released from the toothbrush and the duration of this scent release. Those skilled in the art can readily determine the relative quantity of scenting agent required for a desired release rate of scenting agent (e.g., that will generally be perceived as pleasant to most users) over an extended period (e.g., a projected shelf life of the toothbrush).
The use of multiple thicknesses of the second component to cover a base component comprising a scenting agent will result in multiple rates of release of the scenting agent at different areas of the toothbrush exterior. For example, according to the embodiment of FIG. 5, some projection surfaces 18b of base component 10 may protrude through second component 40 that covers a portion of a gripping region, while other projection surfaces 18a are covered by second component 40. In the case where base component 10 comprises a scenting agent and second component 40 does not, the release rate of scenting agent from projection surface 18b will be higher per unit area than the release rate of scenting agent from projection surface 18a. 
Analogous to the manner in which visibility is varied and controlled, as discussed previously, the rate of scent release can also be varied and controlled. Thus, projection surfaces 18b, covered with second component 40 at a third thickness that is zero, are completely visible and release a maximum rate of scenting agent per unit area of the projection surface 18b. Other projection surfaces 18a that are covered with second component 40 at a second thickness release a relatively lower rate of scenting agent per unit area, due to diffusion limitations through the second component. Adjacent underlying surfaces may be covered at a (still higher) first thickness, such that the release of scenting agent per unit area of these surfaces is minimized.
By varying the thickness with which the second component covers the base component, it is therefore possible to provide varying rates, per unit area, of release of a scenting agent from the base component. Just as projections may be formed with two, three, four, or more discreet degrees of visibility (e.g., by having this number of discreet overlying second component layer thicknesses), these projections may likewise release scenting agent at two, three, four, or more discreet rates per unit area in order to provide a desired combination of sensory (visible and olfactory) effects.
Therefore, according to some embodiments, the rate of scenting agent release per unit area through projection surfaces may correspond (e.g., in a proportionate manner) to the degree of light transmission to (i.e., the visibility of) these surfaces. In other embodiments, these corresponding optical and olfactory effects may not be desired and can be independently regulated. For example, independent control of visibility or projection surfaces is possible by varying the relative transparencies of the base component and second component, while, analogously, independent control of the scenting agent release rate from the projection surfaces is possible by varying the scenting agent concentrations in these components. In view of the present disclosure, it will be appreciated that a number of other factors can be controlled to obtain a desired combination of visibility and scent release properties from projection surfaces, including the component thicknesses, as well as relative light transmission and scenting agent diffusion characteristics of the components.
According to representative embodiments, only one of the two components will possess at least some transparency and/or one of the two components will comprise scenting agent. As discussed above, often the base component is opaque and the second component at least partially transparent. Likewise, often the base component comprises (e.g., is impregnated with) a scenting agent and the second component has none, except for those amounts originating and diffusing from the base component into the second component after these components are adhered.
In addition to the base component and second component, described above, toothbrushes according to the present invention can have other components. For example, a third, elastomeric component can be used in the gripping region, as illustrated by feature 50 of FIG. 4. Third component 50 may be overmolded onto, or co-injection molded with, the base component or other components to provide improved grippability in the gripping region and/or provide other functional components.
In the representative embodiment of FIG. 4, third component 50, namely a thermoplastic elastomer, covers an additional portion of the base component in the gripping region, which is not covered by second component 40. Third component 50, for example, may be used to cover both finger gripping and thumb gripping areas in the gripping region on opposite sides of the toothbrush handle, thereby providing a non-slippery grip surface that improves user control especially in wet or slurry environments. The third component may also be used in the oral engaging region, for example on a side opposite bristle tufts 55 or other cleaning elements on the toothbrush head. In this location, the third component can provide additional functions including tongue cleaning, plaque removal, and/or gum massage.
Representative elastomers suitable for use a third component include thermoplastic elastomers such as those comprising polyolefins (e.g., olefin homopolymers and olefin copolymers), ethylene-propylene rubbers and elastomers (e.g., ethylene propylene diene monomer), styrene-butadiene-styrene, styrene-ethylene-butylene-styrene, polyesters, or polyurethanes. The durometer or hardness values of these elastomeric materials will generally range from about 10 to about 70 Shore A.
Additional components, including other elastomers with 0 to 70 Shore A durometer values, can also be included in toothbrushes described herein. Such additional elastomers will generally have physical and mechanical properties that are different from the third component. Additional elastomers, for example, may be overmolded onto the base component and/or second component in a manufacturing step that is separate from the application of the third component. Additional elastomers may provide aesthetic features and functions that differ from those of the third component.
Toothbrushes described herein thus can provide a number of sensory effects, including visual effects, scenting effects, or combinations of these effects. These effects can result from surfaces such as projection surfaces having multiple degrees of visibility and/or multiple rates of scent release.
Inventive aspects described herein may be incorporated into a manual toothbrush or a powered toothbrush. While the invention has been described with respect to specific examples including presently preferred modes of carrying out the invention, those skilled in the art will appreciate that numerous variations and permutations are possible. It is to be understood that other embodiments may be utilized and structural and functional modifications may be made without departing from the scope of the present invention. Thus, the spirit and scope of the invention should be construed broadly as set forth in the appended claims.

## Claims

1. A toothbrush comprising:
a base component comprising a gripping region and an oral engaging region;
a second component covering, at least a portion of said base component in said gripping region, wherein said base component comprises a plurality of projections in said gripping region;
wherein said base component is opaque and said second component is at least partially transparent; and
wherein a first projection of said plurality of projections is oval in shape and protrudes through said second component so that a periphery of an exposed surface of said first projection is flush with a first portion of an outer surface of said second component that abuts said periphery of said exposed surface of said first projection to form a smooth transition between said second component and said exposed surface of said first projection, wherein a second projection of said plurality of projections has an exposed surface, and wherein edges of said exposed surface of said second projection are recessed below a second portion of said outer surface of said second component that abuts said edges of said exposed surface of said second projection.

2. The toothbrush of claim 1 wherein said base component and said second component are chemically compatible.

3. The toothbrush of claim 2, wherein said base component and said second component comprise a polyolefin.

4. The toothbrush of claim 3, wherein said base component comprises polypropylene.

5. The toothbrush of claim 1 wherein said second component comprises a scenting agent.

6. The toothbrush of claim 1, wherein said second component covers said base component at varying thicknesses.

7. The toothbrush of claim 6 wherein said second component has a maximum thickness of about 5 mm.

8. The toothbrush of claim 1, wherein said plurality of projections comprises features to improve brand recognition.

9. The toothbrush of claim 1 further comprising a plurality of bristle tufts on a first side of the base component in the oral engaging region and a thermoplastic elastomer component in the oral engaging region on a second side of the base component that is opposite the first side.

10. The toothbrush of claim 9 wherein the thermoplastic elastomer component and the second component are injection overmolded on the base component.

11. The toothbrush of claim 1 wherein the gripping region comprises a front surface and an opposing rear surface, and wherein each of the first and second projections extends from the same one of the front or rear surfaces of the gripping region.

12. The toothbrush of claim 11 wherein each of the first and second projections extends from the front surface of the gripping region.

13. A toothbrush comprising:
a base component comprising a gripping region, an oral engaging region, a first projection in the gripping region and a second projection in the gripping region, each of the first and second projections having an exposed surface defined by a peripheral edge;
a second component covering, at least a portion of the base component in the gripping region, the exposed surfaces of the first and second projections being free of coverage by the second component;
wherein the peripheral edge of the exposed surface of the first projection is flush with a first portion of an outer surface of the second component that abuts the peripheral edge of the exposed surface of the first projection to form a smooth transition between the second component and the exposed surface of the first projection, and wherein at least a portion of the peripheral edge of the exposed surface of the second projection is recessed below a second portion of the outer surface of the second component that abuts the peripheral edge of the exposed surface of the second projection.

14. The toothbrush of claim 13 wherein the first portion of the outer surface of the second component surrounds the peripheral edge of the exposed surface of the first projection.

15. The toothbrush of claim 13 wherein the second portion of the outer surface of the second component surrounds the peripheral edge of the exposed surface of the second projection.

16. The toothbrush of claim 13 wherein the gripping region comprises a front surface and an opposing rear surface, and wherein each of the first and second projections extends from the same one of the front or rear surfaces of the gripping region.

17. The toothbrush of claim 16 wherein each of the first and second projections extends from the front surface of the gripping region.

18. A toothbrush comprising:
a base component comprising a gripping region and an oral engaging region, the gripping region having a front surface and an opposing rear surface;
a second component covering at least a portion of said base component in said gripping region, wherein said base component comprises a plurality of projections in said gripping region;
wherein a first projection of said plurality of projections is oval in shape and protrudes through said second component so that an exposed surface of said first projection is flush with an outer surface of said second component to form a smooth transition between said second component and said exposed surface of said first projection, and wherein a second projection of said plurality of projections has an exposed surface that is recessed below said outer surface of said second component; and
wherein each of said first and second projections extends from the same one of said front or rear surfaces of said gripping region.

19. The toothbrush of claim 18 wherein each of said first and second projections extends from said front surface of said gripping region.