Triboelectric toothbrush

Abstract

The present invention relates to an oral care device comprising: a head portion comprising cleaning elements, wherein the cleaning elements comprise polyvinylidene fluoride; and a handle attached to the head portion. The present invention also relates to a method of whitening teeth, the method comprising; providing an oral care device comprising cleaning elements, wherein the cleaning elements comprise polyvinylidene fluoride; and contacting an exterior surface of an oral cavity with the cleaning elements such that an electrical charge is generated at the exterior surface.

Description

[0001] Attorney Docket No. 206017-0315-OOWO

[0002] TITLE

[0003] Triboelectric Toothbrush

[0004] CROSS-REFERENCE TO RELATED APPLICATIONS The present application claims priority to U.S. Provisional Application No. 63 / 789,686, filed April 16, 2025, the disclosure of which is incorporated herein by reference in its entirety.

[0005] BACKGROUND OF THE INVENTION

[0006] Tooth discoloration remains one of the most common cosmetic concerns in oral health, influencing not only patient’s self-esteem and confidence but also dental care habits and treatment decisions. Additionally, teeth whitening is one of the most requested procedures by patients. Teeth become stained due to a combination of factors such as diet, tobacco use, poor oral hygiene, aging, medications, fluorosis, genetics, and enamel erosion from acidic foods.

[0007] To remove tooth-surface stains, different whitening treatments are commonly employed. They can be categorized into professional dental treatments and at-home solutions. Professional treatments are conducted in the dental offices and involve the application of a high concentration bleaching agent, often activated by light or a laser. These bleaching solutions employ aggressive peroxide chemicals which can promote enamel erosion and increase tooth sensitivity. At-home whitening solutions include whitening strips, toothpastes, and rinses. Natural whitening methods with baking soda and hydrogen peroxide may help remove surface stains, but the effectiveness of these at home-solutions vary.

[0008] Conventional tooth-whitening approaches generally depend on externally supplied bleaching agents, abrasive formulations, whitening strips, whitening trays, or professional inoffice bleaching treatments. Such approaches typically require separate active compositions, additional treatment steps, and user compliance beyond routine brushing, and may also be associated with inconvenience, tooth sensitivity, gingival irritation, enamel safety concerns, variable access, and cost.

[0009] Thus, there is a need in the art for teeth whitening solutions. The present invention satisfies this unmet need.

[0010] SUMMARY OF THE INVENTIONAttorney Docket No. 206017-0315-OOWO

[0011] In one aspect, the present invention relates to an oral care device comprising: a head portion comprising cleaning elements, wherein the cleaning elements comprise polyvinylidene fluoride; and a handle attached to the head portion. In some examples, the cleaning elements are selected from the list consisting of bristles, filaments, scrapers, fins, flaps, nodules, pointed structures, polishing cups or pads, textured surfaces, liquid dispensing cavities, and combinations thereof. In some examples, the cleaning elements are bristles. In some examples, the cleaning elements are bristles composed of only polyvinylidene fluoride. In some examples, the cleaning elements are bristles having a diameter of less than 900 pm. In some examples, the cleaning elements further comprise a polyamide. In some examples, the cleaning elements further comprise poly(vinylidene fluoride-co-trifluoroethylene). In some examples, the cleaning elements are star-shaped bristles. In some examples, the cleaning elements are bristles and the head portion further comprises a plurality of tufts comprising the bristles. In some examples, the head portion comprises at least one inner row of tufts and at least one outer row of tufts.

[0012] In one aspect, the present invention relates to an oral care device comprising: a head portion comprising cleaning elements, wherein the cleaning elements comprise a triboelectric material; and a handle attached to the head portion; wherein the cleaning elements are configured to produce an electric charge of at least 10 mV when a frictional force is applied by the cleaning elements to a surface of an object in the oral cavity of a subject. In some examples, the cleaning elements are bristles comprising polyvinylidene fluoride. In some examples, the electric charge produced is at least 60 mV.

[0013] In one aspect, the present invention relates to a method of whitening teeth, the method comprising: providing an oral care device comprising cleaning elements, wherein the cleaning elements comprise poly vinylidene fluoride; and contacting an exterior surface of an oral cavity with the cleaning elements such that an electrical charge is generated at the exterior surface. In some examples, the method further comprises brushing the exterior surface. In some examples, the method further comprises applying a light energy source. In some examples, the exterior surface is the surface of a tooth. In some examples, the electric charge is at least 10 mV. In some examples, the electric charge produces hydrogen peroxide. In some examples, the brushing cleans the exterior surface.

[0014] BRIEF DESCRIPTION OF THE DRAWINGSAttorney Docket No. 206017-0315-OOWO

[0015] The following detailed description of various embodiments of the invention will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings illustrative embodiments. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities of the embodiments shown in the drawings.

[0016] Fig. 1 depicts an exemplary schematic of the inventive whitening process.

[0017] Fig. 2 depicts an exemplary triboelectric toothbrush.

[0018] Fig. 3 depicts a scanning electron microscopy (SEM) image of a single bristle on a triboelectric toothbrush.

[0019] Fig. 4 depicts a chart with the voltage (electrical charge) produced by the triboelectric toothbrush and by a commercial toothbrush.

[0020] Fig. 5 depicts an experimental apparatus for simulated brushing of toothbrush against teeth.

[0021] Fig. 6 depicts images comparing results from the simulated brushing experiments.

[0022] Fig. 7 depicts a chart with the changes in white color on treated teeth from use of a commercial toothbrush, a triboelectric electric toothbrush, and whitening strips.

[0023] Fig. 8 depicts an exemplary brushing machine with three testing slots showing toothbrush brushing heads (arrow).

[0024] Fig. 9, comprising Fig. 9A through Fig. 9C, depicts representative triboelectric toothbrush prototypes and bristle morphology. Fig. 9A depicts a prototype of the manual toothbrush head comprising PVDF bristles of about 0.2 mm diameter. Fig. 9B depicts a prototype of the manual toothbrush head comprising P(VDF-TrFE) bristles of about 0.46 mm diameter. Fig. 9C depicts an SEM image of a representative P(VDF-TrFE) bristle showing successful formation of an individual triboelectric fdament for incorporation into a toothbrush head.

[0025] Fig. 10, comprising Fig. 10A through Fig. 10C, depicts electrical output generated by triboelectric toothbrush prototypes during brushing. Fig. 10A depicts a schematic of the electrical measurement setup used to record voltage generated during brushing, showing bristle contact with the surface and signal acquisition during motion. Fig. 10B depicts voltage-versus-time traces comparing a commercial toothbrush and the PVDF TriboGlow prototype under the Bass brushing technique, showing clear oscillatory electrical output for the PVDF prototype and aAttorney Docket No. 206017-0315-OOWO

[0026] near-baseline signal for the commercial control. Fig. 10C depicts voltage-versus-time traces comparing a commercial toothbrush and the PVDF TriboGlow prototype under the Swivel brushing technique, showing substantially greater electrical output for the PVDF prototype relative to both the commercial control and the Bass condition. Fig. 10D depicts voltage-versus-time traces for the P(VDF-TrFE) TriboGlow prototype comparing the Bass and Swivel brushing techniques, demonstrating that the Swivel motion produces markedly higher electrical output than the Bass motion. Together, these results show that triboelectric charge generation depends on both bristle composition and brushing technique.

[0027] Fig. 11 depicts a representative visual whitening of stained teeth after treatment with a commercial toothbrush, TriboGlow, or whitening strips. Top row: stained teeth before treatment. Bottom row: the corresponding teeth after treatment. For the brushing groups, teeth were brushed for two hours, corresponding to approximately 1 month of twice-daily, two-minute brushing under simulated conditions. TriboGlow-treated teeth showed a visible reduction in brown extrinsic staining and a whiter coronal enamel appearance relative to the commercial toothbrush group, while whitening strips produced the greatest visible whitening effect. Red circles indicate representative enamel regions used for color analysis, and arrows indicate progression from stained to treated condition.

[0028] Fig. 12, comprising Fig. 12A and Fig. 12B, depicts quantitative whitening efficacy of the P(VDF-TrFE) TriboGlow prototype after 1-month equivalent brushing. Fig. 12A depicts Eoo color difference and Fig. 12B depicts AWI D Whiteness Index for Dentistry for teeth treated with a commercial toothbrush, TriboGlow, or whitening strips after two hours of brushing, corresponding to approximately 1 month of twice-daily, two-minute brushing for the brushing groups. In both metrics, the TriboGlow group showed significantly greater whitening than the commercial toothbrush control, while whitening strips produced the greatest effect overall. Different letters indicate statistically significant differences among groups (p < 0.05).

[0029] Fig. 13, comprising Fig. 13A and Fig. 13B, depicts calibration and hydrogen peroxide measurements for the TriboGlow ROS assay. Fig. 13 A depicts a calibration curve for the colorimetric hydrogen peroxide assay used to quantify peroxide generated during simulated brushing. The calibration confirms a concentration-dependent assay response across the tested standard range. Fig. 13B depicts hydrogen peroxide concentration (H2O2, pM) measured after simulated brushing intervals equivalent to 1 month and 3 months for the PVDF TriboGlowAttorney Docket No. 206017-0315-OOWO

[0030] prototype, compared with a commercial toothbrush control and whitening strips. TriboGlow generated more hydrogen peroxide than the commercial toothbrush, while whitening strips produced the highest overall peroxide level. Different letters indicate statistically significant differences among groups.

[0031] Fig. 14 depicts enamel surface roughness (Ra) after 3-month equivalent treatment with the PVDF TriboGlow prototype. Arithmetic mean roughness (Ra, pm) measured for enamel surfaces before treatment, after brushing with a commercial toothbrush, after brushing with the PVDF TriboGlow prototype, and after treatment with whitening strips. The Commercial, TriboGlow, and Before groups were not significantly different from each other, whereas the whitening strips group exhibited significantly greater roughness (p < 0.05). Different letters indicate statistically significant differences among groups.

[0032] Fig. 15, comprising Fig. 15A through Fig. 15D, depicts SEM images of enamel surface morphology after treatment. Representative scanning electron microscopy images of enamel surfaces from the different treatment groups: no treatment (Fig. 15 A), whitening strips (Fig. 15B), commercial toothbrush (Fig. 15C), and TriboGlow PVDF (Fig. 15D). The whitening-strip group showed more pronounced surface irregularity and localized disruption, whereas the commercial toothbrush and TriboGlow PVDF groups showed qualitatively similar brushing-related surface features without obvious severe damage. These images provide qualitative support for the profilometry results, indicating that the PVDF TriboGlow prototype did not measurably increase enamel surface damage relative to conventional brushing.

[0033] DETAILED DESCRIPTION

[0034] Unless otherwise specifically defined herein, all terms are to be given their broadest reasonable interpretation. This includes meanings implied from the specification as well as meanings understood by those skilled in the art and / or as defined in dictionaries, treatises, etc.

[0035] It is noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless otherwise specified. The term “includes” and / or “including,” when used in this specification, specify the presence of stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.Attorney Docket No. 206017-0315-OOWO

[0036] Relative terms such as “horizontal,” “vertical,” “up,” “down,” “top,” and “bottom” as well as derivatives thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then-described or as shown in the drawing figure under discussion. These relative terms are for convenience of description and normally are not intended to require a particular orientation in actuality. Terms including “inwardly” versus “outwardly,” “longitudinal” versus “lateral,” and the like are to be interpreted relative to one another or relative to an axis of elongation, or an axis or center of rotation, as appropriate. Terms concerning attachments, coupling and the like, such as “connected” and “interconnected,” refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. The phrases “operatively” or “operably connected” indicates such an attachment, coupling, or connection that allows the pertinent structures to operate as intended by virtue of that relationship.

[0037] Reference throughout the specification to “one embodiment,” “an embodiment,” or “some embodiments” means that a particular feature, structure, or characteristic described in connection with at least one embodiment of the subject matter is included in at least one embodiment of the subject matter disclosed. Thus, the appearance of the phrases “in one embodiment,” “in an embodiment,” or “In some examples” in various places throughout the specification is not necessarily referring to the same embodiment. Further, the particular features, structures, or characteristics of “one embodiment,” “an embodiment,” or “some embodiments” may be combined in any suitable manner with each other to form additional embodiments of such combinations. It is intended that embodiments of the disclosed subject matter cover modifications and variations thereof. Terms such as “first,” “second,” “third,” etc., merely identify one of a number of portions, components, steps, operations, functions, and / or points of reference as disclosed herein, and likewise to not necessarily limit embodiments of the present disclosure to any particular configuration or orientation.

[0038] Moreover, throughout this disclosure, various aspects can be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the disclosure. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example,Attorney Docket No. 206017-0315-OOWO

[0039] description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as individual numbers within that range, for example, 1, 2, 2.7, 3, 4, 5, 5.3, 6, and any whole and partial increments therebetween. This applies regardless of the breadth of the range. As used herein, the term “about” in reference to a measurable value, such as an amount, a temporal duration, and the like, is meant to encompass the specified value or variations of plus or minus 20%, plus or minus 10%, plus or minus 5%, plus or minus 1%, and plus or minus 0.1% of the specified value, as such variations are appropriate and fit within the confines of a functional system.

[0040] The terms “proximal,” “distal,” “anterior,” “posterior,” “medial,” “lateral,” “superior,” and “inferior” are defined by their standard usage indicating a directional term of reference. For example, “proximal” refers to a position that is situated nearer to the center of a body or point of attachment or interest. In another example, “anterior” refers to the front of a body or structure, while “posterior” refers to the rear of a body or structure, in relation to a relative viewpoint. In another example, “medial” refers to the direction towards the midline of a body or structure, and “lateral” refers to the direction away from the midline of a body or structure. In some examples, “lateral” or “laterally” may refer to any sideways direction. In another example, “superior” refers to the top of a body or structure, while “inferior” refers to the bottom of a body or structure. It should be understood, however, that the directional term of reference may be interpreted within the context of a specific body or structure, such that a directional term referring to a location in the context of the reference body or structure may remain consistent as the orientation of the body or structure changes.

[0041]

[0042] Disclosed herein are exemplary oral care devices comprising cleaning elements, wherein the cleaning elements comprise a triboelectric material. Also disclosed are methods of whitening and cleaning teeth using said oral care devices.

[0043] In some examples, the present invention addresses current limitations of conventional tooth-whitening by integrating whitening function directly into a toothbrush through triboelectric bristles that generate whitening-active chemistry in situ during brushing in the presence of saliva and / or water. In some examples, the present invention allows whitening to be achieved as part ofAttorney Docket No. 206017-0315-OOWO

[0044] routine oral hygiene without requiring separate whitening products or externally applied bleaching agents. In some examples, the present invention provides a lower-barrier, more user-friendly, and lower-peroxide alternative to conventional whitening approaches while preserving a familiar act of daily brushing.

[0045] In some examples, the present invention relates to an oral case device for users seeking whiter teeth and improved dental aesthetics. In some examples, the present invention relates to a toothbrush, toothbrush head, and triboelectric bristle system that generates whitening-active chemistry during brushing. In some examples, the present invention uses bristles fabricated from one or more triboelectric polymers (e.g., polyvinylidene fluoride (PVDF), poly (vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)], and the like), and related triboelectric materials. In some examples, the present invention exploits frictional contact of the inventive bristles with the tooth surface during brushing to generate a localized electrical charge. In some examples, the present invention promotes triboelectric activity (i.e., electrical charge) that promotes formation of a reactive species (e.g., reactive oxygen species, hydrogen peroxide, etc.) at or near the tooth surface. In some examples, the present invention enables stain degradation and tooth whitening during routine brushing without requiring separate whitening gels, strips, trays, externally supplied bleaching agents, batteries, or external devices. In some examples, the present invention includes a manual toothbrush, a replacement brush head, and a brush head configured for use with powered or electric toothbrush systems such that the whitening function is achieved through triboelectric bristles that generate reactive species during brushing. Fig. 1 depicts an exemplary schematic of the inventive process.

[0046] In some examples, the present invention relates to a manual or electric toothbrush comprising triboelectric bristles. In some examples, the present invention relates to a toothbrush head carrying triboelectric bristles, optionally configured as a replaceable head. In some examples, the present invention relates to a brush head configured for attachment to an electric or powered toothbrush handle. In some examples, the present invention relates to a bristle array, tuft arrangement, and brush-head architecture designed to enhance triboelectric charge generation and whitening efficiency. In some examples, the present invention relates to a method of whitening teeth by brushing with triboelectric bristles in the presence of saliva and / or water.Attorney Docket No. 206017-0315-OOWO

[0047] In some examples, the present invention relates to a method of manufacturing for forming, arranging, attaching, and configuring triboelectric bristles for whitening use.

[0048] Oral Care Device

[0049] In some examples, the present invention relates to an oral care device comprising: a head portion comprising cleaning elements and a handle connected to the head portion. In some examples, the oral care device is a toothbrush.

[0050] In some examples, the head portion comprises cleaning elements including, but not limited to, bristles, filaments, scrapers, fins, flaps, nodules, pointed structures, polishing cups or pads, textured surfaces, liquid dispensing cavities, and combinations thereof.

[0051] In some examples, the cleaning elements comprise a material including, but not limited to, polyvinylidene fluoride, poly(vinylidene fluoride-co-trifluoroethylene), poly(vinylidene fluoride-hexafluoropropylene), polyvinylidene chloride, polyvinyl fluoride, polytetrafluoroethylene, fluorinated ethylene propylene, ethylene chlorotrifluoroethylene, ethylene tetrafluoroethylene, polychlorotrifluoroethylene, polyethylene, fluorinated polyethene, polypropylene, polyethylene terephthalate, polyacrylate, polystyrene, polyhydroxybutyrate and other biodegradable polymers, polybenzimidazole, polydimethylsiloxane, nylon, nylon-6, nylon-6,6, polybutylene terephthalate, poly-L -lactic acid, silicone, copper, silver, charcoal, BaTiCh (BTO), activated carbon, fluoride, zinc, zinc oxide, strontium salts, chitosan, cellulose, natural hair, natural flavors, silica, pyrophosphate, hydrogen peroxide, charcoal, potassium nitrate, and combinations thereof. In some examples, the cleaning elements comprise a triboelectric material. In some examples, the cleaning elements comprise a piezoelectric material. In some examples, the bristles are composed of least two of the above materials. In some examples, the bristles are composed of least three of the above materials.

[0052] In some examples, the cleaning elements are bristles comprising one of the above materials. In some examples, the bristles comprise a triboelectric material. In some examples, the bristles are composed only of one or more triboelectric materials. In some examples, the bristles comprise a piezoelectric material. In some examples, the bristles are composed of only one or more piezoelectric materials. In some examples, the bristles include polyvinylidene fluorideAttorney Docket No. 206017-0315-OOWO

[0053] and / or poly(vinylidene fluoride-co-trifluoroethylene). In some examples, the bristles are coated with polyvinylidene fluoride and / or poly(vinylidene fluoride-co-trifluoroethylene).

[0054] In some examples, the bristles are configured on the oral care device to provide excellent whitening and cleaning quality for teeth and interdental spaces. In some examples, the head portion comprises a plurality of tufts comprising bristles. In some examples, the tufts are attached to the head portion intended for insertion into a user's oral cavity. In some examples, the head portion comprises a mounting surface with multiple mounting holes, wherein tufts comprising bristles may be mounted on. In some examples, the head portion comprises at least two tufts inclined in different directions with respect to the mounting surface. In some examples, the head portion comprises a plurality of spaced rows of tufts comprising bristles extending perpendicularly from the head portion. In some examples, the rows of tufts comprising bristles extend the same length. In some examples, the rows of tufts comprising bristles extend varying amounts of lengths. Optionally, a distance / spacing between the tufts within one row may be specified. In some examples, a head portion comprises at least one inner row of tufts and at least one outer row of tufts. In some examples, a row or multiple rows of tufts comprised by the head portion are arranged in a specific pattern, including but not limited to, a circle, a cross, a square, a rectangle, an oval, a diamond, and the like. The stiffness of the tufts of the inner rows may be higher than the stiffness of the tufts of the outer rows. The stiffness of the tufts of the outer rows may be higher than the stiffness of the tufts of the inner rows.

[0055] In some examples, the head portion may have a higher density of bristles in one or more areas of the head portion. In some examples, the head portion comprises a central zone wherein the density of bristles is higher than in the rest of the head portion. In some examples, the bristles may have a substantially regular arrangement in the head portion, so that the number of bristles per unit of surface area on the head portion is substantially equal throughout. In some examples, the bristles may be arranged on the head portion to have a greater concentration (i.e., a greater number of bristles per unit of surface area) in some areas of the head portion than in others. Greater concentrations of bristles may be provided in areas where more vigorous cleaning is desired. In some examples, the bristles may be more densely concentrated towards the ends of the head portion.

[0056] In some examples, the lengths of the individual bristles are at least 100 pm, at least 200 pm, at least 300 pm, at least 400 pm, at least 500 pm, at least 600 pm, at least 700 pm, at leastAttorney Docket No. 206017-0315-OOWO

[0057] 800 pm, at least 900 pm, at least 1 mm, at least 2 mm, at least 3 mm, at least 4 mm, at least 5 mm, at least 6 mm, at least 7 mm, at least 8 mm, at least 9 mm, at least 10 mm, at least 11 mm, at least 12 mm, at least 15 mm, and at least 30 mm. In some examples, the lengths of the individual bristles are less than 100 pm, less than 200 pm, less than 300 pm, less than 400 pm, less than 500 pm, less than 600 pm, less than 700 pm, less than 800 pm, less than 900 pm, less than 1 mm, less than 2 mm, less than 3 mm, less than 4 mm, less than 5 mm, less than 6 mm, less than 7 mm, less than 8 mm, less than 9 mm, less than 10 mm, less than 11 mm, less than 12 mm, less than 15 mm, and less than 30 mm.

[0058] In some examples, the individual bristles have a cross-section, which can be of any shape including, but not limited to, circular, oval, square, rectangular, hexagonal, a cross, a star, and the like. In some examples, each individual bristle has a diameter defined by the length of a straight line that passes through the center of the bristles cross-sectional area and whose endpoints lie on the most outer points of the cross-sectional area. In some examples the diameter of a single bristle is between about 1 pm to about 5 mm. In some examples, the diameter of a single bristle is at least 1 pm, at least 5 pm, at least 25 pm, at least 50 pm, at least 75 pm, at least 100 pm, at least 150 pm, at least 200 pm, at least 250 pm, at least 300 pm, at least 350 pm, at least 400 pm, at least 450 pm, at least 500 pm, at least 550 pm, at least 600 pm, at least 650 pm, at least 700 pm, at least 750 pm, at least 800 pm, at least 850 pm, and at least 900 pm. In some examples, the diameter of a single bristle is less than 1 pm, less than 5 pm, less than 25 pm, less than 50 pm, less than 75 pm, less than 100 pm, less than 150 pm, less than 200 pm, less than 250 pm, less than 300 pm, less than 350 pm, less than 400 pm, less than 450 pm, less than 500 pm, less than 600 pm, less than 700 pm, less than 800 pm, and less than 900 pm. In some examples, the diameter of a single bristle is about 1 pm, about 5 pm, about 25 pm, about 50 pm, about 75 pm, about 100 pm, about 150 pm, about 200 pm, about 250 pm, about 300 pm, about 350 pm, about 400 pm, about 450 pm, about 500 pm, about 550 pm, about 600 pm, about 650 pm, about 700 pm, about 750 pm, about 800 pm, about 850 pm, and about 900 pm. In some examples, the diameter at the bottom of the bristle closest to the head portion is larger in length than the diameter at the cleaning end of the bristle. In some examples, the diameter at the bottom of theAttorney Docket No. 206017-0315-OOWO

[0059] bristle closest to the head portion, is smaller in length than the diameter at the cleaning end of the bristle.

[0060] In some examples, a tuft of bristles has a packing factor, defined as the total sum of the transverse cross-sectional areas of the filaments in a tuft hole divided by the transverse cross-sectional area of the tuft hole which a tuft is mounted on. In some examples, a tuft composed of cross-shaped bristles possesses a relatively low packing factor as compared to tufts composed of circular shaped filaments. In some examples, a tuft may have a packing factor between about 30% to about 75%.

[0061] In some examples, the cleaning ends of the bristles can be of any desired shape, such as cutting at a right angle, cutting with a rounded, pointed, or any outlined shape. In some examples, each individual bristle is not absolutely identical to the other bristles. In some examples, the bristles of the device can have various diameters or cross-sectional shapes.

[0062] In some examples, the oral care device is an electric toothbrush. In some examples the oral care device comprises an electrically powered element that is mechanically coupled to the oral care device and is configured for imparting driven movement to the device. In some examples, the electrically powered element includes a motor electrically connected to a battery. In some examples, the battery is rechargeable. In some examples, the motor is a conventional DC motor. In some examples, the electrically powered element includes a control unit which for example can control the speed of the motor. In some examples, the electrically powered element includes a driving module, which in some cases is electrically connected to the battery, wherein the battery is configured to supply a voltage to the driving module, which then converts the voltage to an ultrasonic frequency. In some examples, the oral care device includes a vibrating actuator coupled to the electrically powered element, which is configured to vibrate some of the cleaning elements comprised in the head portion.

[0063] In some examples, the oral device delivers both an electrical charge and ultrasonic frequency or vibrational energy.

[0064] In some examples, the oral care device comprises a head portion comprising cleaning elements, wherein the cleaning elements comprise a triboelectric material; and a handle attached to the head portion; wherein the cleaning elements are configured to produce an electric charge of at least 10 mV when a frictional force is applied by the cleaning elements to a surface of an object in the oral cavity of a subject. In some examples, the cleaning elements are bristlesAttorney Docket No. 206017-0315-OOWO

[0065] comprising polyvinylidene fluoride. In some examples, the electric charge produced is at least 60 mV.

[0066] In some examples, the present invention comprises a manual toothbrush having a handle and a brush head that carries an array of triboelectric bristles arranged in tufts or other suitable bristle groupings. In some examples, the invention comprises a replacement brush head configured to attach to a manual, powered, oscillating, vibrating, sonic, or other electric toothbrush handle. In some examples, the whitening function is provided by the bristles themselves, which are fabricated wholly or partly from triboelectric material capable of generating localized charge upon brushing contact with tooth surfaces.

[0067] In some examples, the bristles may be arranged as a full field of triboelectric bristles or as selected triboelectric tufts positioned in specific zones of the brush head. In some examples, the bristles may be uniform or mixed in diameter, stiffness, length, spacing, orientation, shape, or density. In some examples, the triboelectric bristles may be the only bristles on the brush head or may be combined with non-triboelectric bristles for additional cleaning, polishing, plaqueremoval, comfort, or structural functions. In some examples, the brush head may be fixed or replaceable and may be configured in any suitable geometry for contacting anterior and posterior tooth surfaces.

[0068] In some examples, the bristles are solid polymer filaments formed from triboelectric materials. In some examples, the triboelectric component may be present as a full bristle, a coating on a bristle core, an outer layer surrounding a non-triboelectric core, a multilayer or coaxial structure, or a composite architecture that includes triboelectric polymer in combination with one or more additional materials. In some examples, the brush head architecture, tuft arrangement, bristle geometry, and distribution of triboelectric bristles may be selected to enhance contact efficiency, brushing comfort, charge generation, whitening performance, durability, or manufacturability.

[0069] The invention is not limited to any one head shape, tuft pattern, or handle design, provided that the toothbrush or brush head includes triboelectric bristles configured to generate whitening-active chemistry during brushing. This broad device concept is consistent with the current development direction, which includes protection of the triboelectric bristles, the brush arrangement, and brush heads adapted for use with powered toothbrush systems.Attorney Docket No. 206017-0315-OOWO

[0070] In some examples, the present invention relates to toothbrushes and brush heads incorporating triboelectric bristles fabricated from PVDF, P(VDF-TrFE), and other triboelectric polymers, copolymers, blends, composites, filled polymers, coated filaments, layered bristles, or core-shell bristle architectures capable of generating charge during brushing. In some examples, the triboelectric material may constitute the full bristle or may be present as a coating, outer shell, surface layer, or discrete region of a more complex bristle structure. Bristles may be straight, tapered, textured, ridged, split, porous, hollow, curved, angled, or otherwise shaped to influence brushing mechanics, triboelectric response, whitening performance, comfort, or durability.

[0071] In some examples, the present invention relates to different brush-head architectures and tuft arrangements, including full-head triboelectric bristle arrays, mixed heads containing both triboelectric and non-triboelectric bristles, zoned distributions of triboelectric bristles, variable tuft density, different filament counts per tuft, different exposed bristle lengths, and mixed stiffness designs. Such embodiments may be used to optimize frictional contact, electrical output, whitening performance, user comfort, bristle wear, or manufacturability.

[0072] In some examples, the present invention relates to replacement brush heads and brush heads designed for powered toothbrush handles, including oscillating, rotating, vibrating, sonic, and other electrically actuated toothbrush systems. In these embodiments, the triboelectric whitening function may be enhanced, modified, or tuned by the motion profile of the powered handle. In some examples, the present invention includes both manual and powered implementations, even where only manual prototypes have been physically built to date.

[0073] In some examples, the present invention relates to methods of whitening teeth via triboelectric brushing, methods of generating reactive oxygen species or hydrogen peroxide at the tooth surface during brushing, methods of reducing tooth stain accumulation through repeated triboelectric brushing, and methods of integrating triboelectric whitening into a routine oral hygiene regimen. In some examples, the present invention includes methods of extruding triboelectric bristles, assembling them into tufts, attaching them to toothbrush heads, bonding or anchoring them into manual or powered heads, and optimizing processing parameters to control diameter, flexibility, triboelectric output, and durability.

[0074] In some examples, the present invention relates to bristles or brush heads designed to operate with saliva alone, with water, with dentifrice, or with specially formulated toothpastes orAttorney Docket No. 206017-0315-OOWO

[0075] rinses that do not themselves contain conventional whitening levels of peroxide but may enhance triboelectric activity or stain removal. In some examples, the present invention extends to oralcare devices beyond standard toothbrushes, such as polishing brushes, interproximal brushes, denture-cleaning brushes, aligner-cleaning brushes, or other mechanically actuated oral-contact devices in which triboelectric bristles generate whitening-active chemistry during use.

[0076] Method of Whitening and Cleaning Teeth

[0077] In some examples, the present invention relates to a method of whitening teeth, the method comprising: providing an oral care device comprising cleaning elements, wherein the cleaning elements comprise a triboelectric material; and contacting an exterior surface of an oral cavity with the cleaning elements such that an electrical charge is generated at the exterior surface. In some examples, the triboelectric material includes polyvinylidene fluoride and / or poly(vinylidene fluoride-co-trifluoroethylene). In some examples, the exterior surface includes the surface of a tooth, a gum, a tongue, a cheek, or any other surface inside of an oral cavity. In some examples, the step of contacting the exterior surface cleans the exterior surface. The oral care device and its cleaning elements are described elsewhere herein. In some examples, the cleaning elements are bristles.

[0078] In some examples, the step of contacting the exterior surface of an oral cavity with the cleaning elements comprises brushing the exterior surface with the cleaning elements. In some examples, the friction created by the brushing of the exterior surface excites the triboelectric material in the cleaning elements, which generates a stimulus. In some examples the stimulus is an electrical charge. In some examples, the method comprises brushing the exterior surface of a tooth with bristles to produce and electric charge at the surface of the tooth. In some examples the electric charge produced is at least 1 mV, at least 2 mV, at least 5 mV, at least 10 mV, at least 15 mV, at least 20 mV, at least 25 mV, at least 30 mV, at least 35 mV, at least 40 mV, at least 45 mV, at least 50 mV, at least 55 mV, at least 60 mV, at least 65 mV, at least 70 mV, at least 75 mV, at least 80 mV, at least 100 mV, at least 150 mV, at least 200 mV, at least 250 mV, and at least 500 mV. In some examples the electric charge produced is less than 1 mV, less than 2 mV, less than 5 mV, less than 10 mV, less than 15 mV, less than 20 mV, less than 25 mV, less than 30 mV, less than 35 mV, less than 40 mV, less than 45 mV, less than 50 mV, less than 55 mV, less than 60 mV, less than 65 mV, less than 70 mV, less than 75 mV, less than 80 mV, less thanAttorney Docket No. 206017-0315-OOWO

[0079] 100 mV, less than 150 mV, less than 200 mV, less than 250 mV, and less than 500 mV. Tn some examples the electric charge produced is about 1 mV, about 2 mV, about 5 mV, about 10 mV, about 15 mV, about 20 mV, about 25 mV, about 30 mV, about 35 mV, about 40 mV, about 45 mV, about 50 mV, about 55 mV, about 60 mV, about 65 mV, about 70 mV, about 75 mV, about 80 mV, about 100 mV, about 150 mV, about 200 mV, about 250 mV, and about 500 mV.

[0080] In some examples, the electrical charge reacts with water / moisture / saliva inside the oral cavity and produces a reactive oxygen species which can whiten the tooth. In some examples, the reactive oxygen species a peroxide including, but not limited to, hydrogen peroxide. In some examples, brushing a tooth with the cleaning elements described herein may produce an electrical charge at the exterior surface of the tooth, which may produce a reactive oxygen species.

[0081] In some examples, the method further comprises delivering ultrasonic and / or vibrational energy to the exterior surface. In some examples, the ultrasonic and / or vibrational energy facilitates in creating the electrical charge generated by the cleaning elements.

[0082] In some examples, the method above further comprises applying an oxidizing composition comprising an oxidizing agent to the tooth including, but not limited to, peroxides, metal chlorites, percarbonates, perborates peroxyacids, hypochlorites, hydrogen peroxide, carbamide peroxide, poly(vinyl pyrrolidone)-hydrogen peroxide complex (Peroxydone®, ISP Corp, Wayne, N.J.), peroxyacetic acid, sodium chlorite, and combinations thereof.

[0083] The oxidizing composition may also comprise active components further related to the tooth whitening function including, but not limited to, stabilizers, an oxidation catalyst, a pH-adjusting agent, a calcium chelating agent, or to a non-tooth whitening function (such as remineralization of the tooth surface, prevention of tooth decay, tooth-desensitization, prevention of gingivitis and / or periodontal disease, and other diseases or conditions of the oral cavity).

[0084] The combination of whitening and cleaning method described herein may also be practiced by employing an additional source of energy to accelerate the oxidation process and further reduce the time needed to complete the procedure. External energy sources such as electromagnetic or light energy, sound or ultrasound energy, mechanical or vibrational energy,Attorney Docket No. 206017-0315-OOWO

[0085] electrical energy, or combinations thereof may be advantageously employed at any point in time during the combination whitening and cleaning procedure to accelerate the process.

[0086] EXPERIMENTAL EXAMPLES

[0087] The invention is further described in detail by reference to the following experimental examples. These examples are provided for purposes of illustration only, and are not intended to be limiting unless otherwise specified. Thus, the invention should in no way be construed as being limited to the following examples, but rather, should be construed to encompass any and all variations which become evident as a result of the teaching provided herein.

[0088] Without further description, it is believed that one of ordinary skill in the art can, using the preceding description and the following illustrative examples, make and utilize the materials, devices, and kits of the present invention and practice the claimed methods. The following working examples, therefore, specifically point out exemplary embodiments of the present invention, and are not to be construed as limiting in any way the remainder of the disclosure.

[0089] Example 1: Triboelectric Toothbrush

[0090] Presented herein is a novel toothbrush engineered with bristles capable of generating low concentrations of hydrogen peroxide through mechanical brushing. The bristles are fabricated from a triboelectric material that, upon contact and friction with the teeth, locally produces electrical charges. These charges react with the water / saliva naturally present in the oral environment to generate hydrogen peroxide in-situ, enabling a low-dose whitening process during routine brushing. This approach integrates stain removal directly into a daily oral hygiene practice, eliminating the need for additional whitening trays, gels, mouthpieces or routine. Unlike conventional whitening methods that often cause tooth sensitivity and gum irritation due to high peroxide concentrations, this system leverages a gentle, self-activating mechanism that is both safe and user-friendly. The simplicity and convenience of this dual-action cleaning and whitening process may also increase motivation for consistent oral care, promoting both aesthetic and cleaning benefits from a single daily brushing. This disruptive technology has the potential to redefine home whitening treatments by making more accessible and seamlessly embedded in everyday behavior.Attorney Docket No. 206017-0315-OOWO

[0091] The present invention relates to a novel toothbrush incorporating triboelectric bristles fabricated from a polyvinylidene fluoride (poly(vinylidene fluoride-co-trifluoroethylene) or (PVDF-TrFE)), a biocompatible material with triboelectric properties. The toothbrush harnesses the mechanical action of brushing to generate an electric charge, which subsequently leads to the production of reactive oxygen species (ROS), including hydrogen peroxide. The production of these ROS effectively removes stains from teeth without the use of abrasive chemical whitening agents found in conventional whitening treatments. The triboelectric effect also eliminates the need for batteries or external power sources, making it a safe and sustainable process.

[0092] The toothbrush bristles are manufactured using advanced fabrication techniques, including 3D printing and extrusion-based methods to ensure optimal triboelectric properties and mechanical stability. PVDF-TrFE, known for its strong piezoelectric and triboelectric characteristics, was chosen due to its ability to generate electric charges when subjected to mechanical deformation. During brushing, friction between the PVDF-TrFE bristles and teeth induces a triboelectric effect, leading to charge accumulation. The design of the bristles ensures maximum surface contact and friction, enhancing charge generation and stain removal efficiency. This innovation offers a chemical-free and energy-efficient method of dental whitening, leveraging the user’s natural brushing action to activate the whitening process.

[0093] Additionally, the toothbrush can be adapted for different bristle stiffness levels and designs to cater to various oral care needs.

[0094] The triboelectric device was fabricated and shown in Fig. 2. The bristles were obtained by extruding a filament of PVDF-TrFE through a nozzle heated at 200°C, rendering bristles with a diameter of 0.46 mm (Fig. 3). The electrical charges (voltage) produced by the bristles during brushing against a contact surface were measured using a high-impedance voltmeter (Keithley). During brushing, the device produced a peak-to-peak voltage of 60 mV (Fig. 4). A commercial toothbrush did not produce any charge as expected. The charges are expected to produce the peroxide required for stain removal after contact with water or saliva.

[0095] Extracted teeth were stained after immersion for one week in a 50 / 50 mixture of coffee and grape juice simulating common dietary staining. These ingredients are challenging to remove since they can percolate into the porous structure of the enamel. Following staining, the teeth were mounted onto a brushing machine designed to replicate realistic oral hygieneAttorney Docket No. 206017-0315-OOWO

[0096] routines — applying ~4N of pressure at a frequency of one cycle per second for a total of two hours, equivalent to approximately one month of brushing twice daily for two minutes (Fig. 5).

[0097] The whitening performance of the device was both visually and quantitatively assessed alongside the control groups (commercial toothbrush - Colgate ExtraClean and of-the-counter whitening strips - Crest 3D Whitestrips-applied as instructed) with N=9 per group. Photos of the stained teeth before and after treatment were taken inside a light-controlled shooting tent, using a fixed camera position to ensure consistent lighting and imaging conditions. Color analysis was performed by quantifying the white pixel intensity within defined regions of interest (circles in Fig. 6) in the before and after treatment images. The change in whiteness was then calculated. Visually, teeth brushed with the inventive device showed a striking improvement in white shade, comparable to whitening strips and clearly outperforming the commercial toothbrush, which showed no noticeable whitening effect (Fig. 6). Quantitatively, while whitening strips produced the highest white value, the triboelectric toothbrush closely followed demonstrating strong whitening capability after brushing for 2 months twice a day. As expected, the commercial toothbrush showed no improvement in whiteness (Fig. 7).

[0098] All together, these findings support the potential of the technology to remove stains from teeth through just routine brushing alone, validating the triboelectric concept as a feasible, low-peroxide, over-the-counter alternative for tooth whitening

[0099] To accelerate performance, it is critical to optimize the triboelectric toothbrush’s bristles diameter, confirm enamel safety through surface analyses, evaluate whitening performance under varied brushing conditions, and demonstrate broad efficacy across common staining models. These evaluations will collectively confirm the safety, durability, and consistent performance of the device, ensuring it is ready for consumer use and regulatory submission. The bristle manufacturing process will be refined to produce filaments with a target diameter of 0.20 mm, which falls within the medium-firm category of toothbrushes as outlined in ISO specifications. To achieve this, a 0.2 mm extrusion nozzle will be utilized to fabricate thinner PVDF triboelectric filaments. Bristle stiffness and mechanical properties will be quantified using a universal testing machine (ElectroForce 5500). Scanning electron microscopy (SEM) will be employed to measure the bristle diameter and assess uniformity and cross-sectional integrity.

[0100] In addition, the standardized ISO 20126 chemical challenge test will be performed to evaluate bristle durability and chemical resistance under simulated oral care conditions. TheAttorney Docket No. 206017-0315-OOWO

[0101] bristles will be immersed in a challenge solution composed of L-carvone, L-menthol, sodium lauryl sulfate, ethanol, glycerin, and purified water. Following 24 hours of exposure without agitation, the brushes will be rinsed and subjected to fatigue resistance testing. The brush head will be positioned perpendicular to a test block and apply a cyclic load of 4.0 N for 75,000 cycles. Breakage points will be recorded, and performance data will guide iterative improvements in bristle composition and structure.

[0102] To validate the functional output of the triboelectric bristles, the amount hydrogen peroxide after brushing will be measured. Toothbrushes will be immersed in distilled water and brushing activated simulating cycles equivalent to 1 to 6 months of twice-daily use. A colorimetric assay kit for hydrogen peroxide detection (Sigma- Aldrich, MAK 165) in aqueous solutions will be used. This test will help determine the amount of peroxide per time and whether the bristles continue producing peroxide after extended use.

[0103] The whitening efficacy and enamel safety of the inventive device will be measured under various staining and brushing conditions, comparing its performance to both commercial toothbrushes and over-the-counter whitening strips. The device's efficacy will be assessed against two clinically relevant staining models: 1) a mixture of black tea and red wine and 2) a mixture of coffee and soy sauce. These models were selected based on their high staining potential and known difficulty in removing extrinsic stains. Extracted human teeth will be immersed in each solution for 7 days followed by rinsing and drying for subsequent color evaluation. Following staining, teeth will be assigned to one of three treatment groups: 1) brushing with the triboelectric toothbrush, 2) brushing with a commercial toothbrush (Colgate ExtraClean mid firm), and 3) treatment with commercial whitening strips (Crest 3D Whitestrips). Brushing will be performed using a programmable mechanical brushing simulator set to deliver 4 N of force at 1 Hz. To simulate extended use, brushing will be conducted for a duration equivalent to one year of use (twice daily for two minutes per session), with intermediate assessments taken at time points equivalent to 1, 3, 6, and 12 months of use. All groups will use a standardized non-whitening toothpaste to isolate the effects of the toothbrush mechanism.

[0104] Whitening will be quantitatively measured using a dental spectrophotometer (Vita Easyshade), and color change will be analyzed using the AE metric. Regions of interest on the tooth surface will be digitally defined and consistently measured across the time points. A AEAttorney Docket No. 206017-0315-OOWO

[0105] value greater than 2.7 will be considered clinically perceptible, and a value above 3.3 will be considered clinically acceptable for whitening.

[0106] To assess potential enamel damage, enamel surface roughness is measured before and after brushing using non-contact profilometry (Ra and Rz values), and surface morphology will be analyzed via SEM. This detects any microscopic surface changes or loss of enamel integrity that may result from prolonged brushing or peroxide exposure. To ensure the robustness and scientific validity of the findings, all experiments employ an appropriate number of samples determined by power analysis, and data is analyzed using statistically methods tailored to each test, ensuring unbiased and reproducible results.

[0107] Example 2: TriboGlow: Triboelectric Toothbrush and Brush Head System for In Situ Tooth Whitening During Routine Brushing

[0108] During brushing, triboelectric bristles composed of materials such as PVDF, P(VDF-TrFE), and related triboelectric polymers undergo frictional interaction with the tooth surface and generate localized electrical charge. In the presence of saliva and / or water, this charge promotes one or more electrochemical and / or tribochemical reactions leading to the formation of whitening-active species, including reactive oxygen species and, In some examples, hydrogen peroxide. These species interact with tooth stains and discoloring compounds at or near the enamel surface, enabling stain degradation and visible whitening.

[0109] A central distinction of this invention is that the whitening action arises from the triboelectric bristles themselves rather than from release, leaching, or application of a preloaded whitening gel, strip, paste, or other separate active composition. In other words, the toothbrush bristles are not merely passive mechanical cleaning elements; they serve as the functional source of localized charge generation and associated whitening chemistry during brushing. This distinction is important because it separates the present technology from conventional whitening products that rely on externally provided peroxide, abrasive formulations, or dedicated bleaching systems. The current supporting materials describe this mechanism using PVDF bristles and associate brushing-induced charge generation with peroxide formation and whitening performance.

[0110] Materials and Bristle ArchitecturesAttorney Docket No. 206017-0315-OOWO

[0111] Prototypes have been developed using triboelectric polymers, including PVDF and P(VDF-TrFE). These materials are of interest because they can generate electrical charges in response to frictional contact and are suitable for fabrication into flexible bristle-like elements. Current prototype work has explored bristle diameters in the approximate range of 0.1 mm to 0.6 mm, spanning softer to harder bristle configurations, with the expectation that bristle dimensions and mechanical properties may influence triboelectric output, durability, brushing feel, and whitening performance.

[0112] Although initial prototypes were fabricated using PVDF and P(VDF-TrFE), the invention is not limited to these specific materials. Rather, the invention is intended to encompass other triboelectric polymers, copolymers, blends, composites, filled polymers, coated filaments, multilayer filaments, and related bristle architectures capable of generating localized charge during brushing and promoting the formation of whitening-active species at the tooth surface. In some examples, the triboelectric material may form the entire bristle. In other embodiments, the triboelectric material may be present as a coating, shell, layer, or region of a bristle having a different core or support material.

[0113] The bristles may be configured as straight, tapered, textured, ridged, split, curved, angled, hollow, porous, or otherwise shaped elements, and different bristle populations may be combined in a single brush head. The triboelectric bristles may also be used in combination with conventional bristles to provide desired tradeoffs among whitening, plaque removal, brushing comfort, softness, and wear resistance. Bristle architecture may further include variation in tuft density, tuft spacing, filament count per tuft, exposed bristle length, and surface morphology to optimize triboelectric performance and practical use. In this manner, the invention includes both the specific triboelectric polymers currently tested and a broader family of bristle materials and architectures that operate according to the same triboelectric whitening principle.

[0114] Prototypes

[0115] 20 manual toothbrush prototypes have been fabricated incorporating triboelectric bristles, including 15 PVDF -based prototypes and 5 P(VDF-TrFE)-based prototypes. Bristle diameters ranged from approximately 0.1 mm to 0.6 mm. The brush heads were designed to resemble a conventional manual toothbrush, using an approximately standard tuft arrangement of about 30 tufts per head and about 30 bristles per tuft. Bristles were fabricated by extrusion, manuallyAttorney Docket No. 206017-0315-OOWO

[0116] inserted into the toothbrush head, and then bonded in place. No electric toothbrush head prototype has yet been built, although such embodiments are contemplated.

[0117] The present prototypes have primarily served as exemplary embodiments to establish the feasibility of the triboelectric whitening principle in a realistic manual toothbrush format. PVDF-based prototypes have generated measurable whitening efficacy, reactive oxygen species, and enamel surface safety data, including roughness-related measurements and scanning electron microscopy imaging. These results support not only the whitening efficacy and the proposed mechanism of action based on ROS-mediated stain degradation, but also the feasibility of assessing safety-relevant surface effects using the same general prototype platform. Initial whitening studies further showed that TriboGlow prototypes produced measurable electrical output during brushing and achieved whitening performance exceeding that of a conventional commercial toothbrush in stained extracted teeth.

[0118] Methods

[0119] Studies were conducted using manual toothbrush prototypes incorporating triboelectric PVDF bristles to evaluate whether the bristles could generate measurable electrical output during brushing, promote tooth whitening, produce reactive oxygen species, including hydrogen peroxide, and maintain preliminary enamel surface safety under simulated brushing conditions.

[0120] Prototype fabrication: PVDF (and P(VDF-TrFE)) bristles were fabricated by extrusion at approximately 210°C using high-precision micro-nozzles to produce bristles with diameters ranging from 0.1 mm to 0.6 mm . The extruded fibers were cut into segments of about 12 mm in length, grouped into tufts of 30 fibers, and assembled into a commercially available manual toothbrush handle. The tufts were fixed into the toothbrush head using a UV-curable resin adhesive, generating a PVDF-bristled manual toothbrush prototype suitable for simulated brushing studies.

[0121] Tooth staining protocol: Extracted teeth were artificially stained prior to treatment using a staining solution composed of 200 mL red wine, 200 mL grape juice, 10 g instant coffee, and 10 g black tea. Teeth were submerged in this staining mixture for 15 days, after which they were rinsed, dried, and prepared for experimentation. This staining model was selected to generate visible extrinsic discoloration for subsequent whitening assessment.Attorney Docket No. 206017-0315-OOWO

[0122] Experimental groups: Stained teeth were assigned to treatment groups designed to compare the triboelectric toothbrush against conventional and commercially available whitening approaches. The tested groups included: (1) brushing with the PVDF triboelectric toothbrush in the presence of sterilized saliva and commercial toothpaste (Colgate Cavity Protection); (2) brushing with a commercial toothbrush in the presence of sterilized saliva and commercial toothpaste; and (3) treatment with commercially available whitening strips according to the manufacturer’s instructions. The commercial toothbrush control used was a Colgate Gum Health Adult Manual Toothbrush. The commercial strips were 3D Whitestrips Professional Effects from Oral B.

[0123] Brushing simulation: For the brushing groups, the tooth specimens and toothbrushes were mounted in a brushing machine configured to provide controlled and reproducible brushing motion (Fig. 8). Brushing was performed under a load of approximately 4 N, selected to simulate normal manual toothbrushing force. Treatment durations were selected to represent cumulative equivalents of 1 month of brushing based on a regimen of 2 minutes twice per day. This design enabled assessment of time-dependent whitening, hydrogen peroxide generation, and enamel surface effects under standardized brushing conditions. The brushing platform was used to maintain consistent contact conditions between the toothbrush bristles and the tooth surface across experiments.

[0124] Electrical output measurements: Electrical charge generation by TriboGlow during brushing was evaluated to assess the triboelectric activity of the prototype bristles. The toothbrush was brushed against a copper tape contact surface under controlled mechanical loading conditions representative of routine brushing. Two clinically relevant brushing motions were used for charge measurements, namely the Bass technique and the Swivel technique, in order to determine whether brushing mode influenced triboelectric output. Electrical signal generation was measured using a high-impedance charge amplifier (Piezo Film Lab Amplifier, TE Connectivity) operated in voltage mode with the impedance set at 1 GQ. The generated electrical signal (voltage versus time) was recorded using a data acquisition system (USB-6001, Lab VIEW). Brushing was performed under an applied force of approximately 4 N.

[0125] Measurements were conducted under dry conditions and without signal amplification. These measurements were used to quantify the presence and time profile of triboelectrically generatedAttorney Docket No. 206017-0315-OOWO

[0126] electrical output during brushing and to support the proposed mechanism whereby bristle-surface friction promotes the generation of whitening-active reactive species.

[0127] Whitening assessment: Whitening efficacy was evaluated using a digital spectrophotometer (VITA Easyshade V; VITA Zahnfabrik, Bad Sackingen, Germany). Prior to each measurement session, the instrument was calibrated according to the manufacturer’s instructions. Color measurements were obtained from the central labial surface of each tooth specimen, with the optical probe positioned perpendicular to the enamel surface to standardize measurement geometry. For each specimen, three replicate measurements were recorded from the same central area, and the mean L*, a*, and b* values were used for analysis. Color differences were calculated using the CIEDE2000 (AE00) formula, using the stained, pretreatment tooth condition as the baseline reference. Thus, AE00 values represented the color change between the stained baseline and the corresponding post-treatment brushing-equivalent interval. Standardized photographic images were additionally collected to document visual changes in tooth appearance before and after treatment. Whitening efficacy was evaluated with N = 8 specimens per group.

[0128] In addition to AE00, tooth whiteness was quantified using the Whiteness Index for Dentistry (WI_D), a CIELAB-based index developed specifically for dental applications and shown to correlate with perceived tooth whiteness. WI_D was calculated from the measured L*, a*, and b* values using the formula: WI_D = 0.51 IL* - 2.324a* - 1.100b*. For each tooth specimen, AWI D was determined as the difference between the post-treatment WI_D value and the stained, pre-treatment baseline WI_D value, such that higher positive AWI D values indicated greater whitening. This metric was used alongside AE00 to provide a complementary assessment of treatment-related changes in dental whiteness.

[0129] Reactive oxygen species / hydrogen peroxide measurement: Hydrogen peroxide production was quantified using a colorimetric assay kit (Sigma-Aldrich, MAK165). Prior to analysis of experimental samples, a calibration curve was generated using hydrogen peroxide standards according to the manufacturer’s instructions to validate assay performance and enable quantitative conversion of absorbance values into peroxide concentration. For experimental measurements, toothbrushes were operated under the same simulated brushing conditions used for whitening-efficacy testing, including a brushing force of approximately 4 N. Peroxide was measured after simulated brushing intervals equivalent to approximately 1 month and 3 monthsAttorney Docket No. 206017-0315-OOWO

[0130] of use. After each brushing-equivalent interval, hydrogen peroxide in the aqueous medium was quantified against the calibration curve. The tested groups included TriboGlow 1 month, TriboGlow 3 months, Commercial toothbrush 1 month, and whitening strips. These measurements were used as direct evidence that triboelectric brushing with PVDF bristles generated ROS-related whitening chemistry. ROS measurements were performed with N = 3 specimens per group.

[0131] Surface roughness assessment: Enamel surface roughness was quantitatively determined after treatment using a contact profilometer (Phase 11+ SRG-4600) equipped with a stylus tip radius of 5 pm operating at a constant stylus force of 0.75 mN. For the dataset shown here, roughness was evaluated after a simulated brushing interval equivalent to approximately 3 months of use for the brushing groups. Surface profiles were acquired from three randomly selected locations on each specimen, using a minimum scan length of 0.25 mm per location to provide a representative statistical sampling of the treated enamel surface. Standard roughness parameters were calculated from the acquired topographic data, including arithmetic mean roughness (Ra, pm). All measurements were performed at a scanning speed of 0.5 mm / s with a vertical resolution of 0.01 pm. These analyses were used to compare enamel surface changes before treatment and after treatment with the PVDF triboelectric toothbrush, commercial toothbrush, and whitening strips.

[0132] SEM imaging: To further assess preliminary enamel surface safety, treated tooth surfaces were also examined by scanning electron microscopy (SEM). SEM imaging was used to qualitatively compare surface morphology among groups and to identify visible features such as abrasion patterns, surface disruption, or gross topographic differences following treatment. These images complemented the profilometry -based roughness measurements and provided an additional surface-safety assessment within the same platform. SEM-based evaluation was performed with N = 3 specimens per group.

[0133] Summary of methodological scope: Collectively, these methods were designed to address four linked questions: (1) whether PVDF triboelectric bristles generate measurable electrical output during brushing; (2) whether brushing with such bristles can whiten stained teeth; (3) whether triboelectric brushing is associated with measurable hydrogen peroxide / ROS production; and (4) whether enamel surface effects can be preliminarily assessed using roughness and SEM-based analyses.Attorney Docket No. 206017-0315-OOWO

[0134] Efficacy and Safety Results

[0135] Prototype fabrication and Demonstration of Triboelectric Toothbrush Heads:

[0136] Manual toothbrush prototypes incorporating triboelectric polymer bristles were successfully fabricated in a realistic toothbrush format, demonstrating that the TriboGlow concept can be embodied in brush heads comparable to conventional manual toothbrushes. As shown in Fig. 9A, PVDF bristles with an approximate diameter of 0.2 mm were integrated into a manual toothbrush head, yielding a soft-bristle configuration. As shown in Fig. 9B, a second prototype was fabricated using P(VDF-TrFE) bristles with an approximate diameter of 0.46 mm, corresponding to a medium-bristle configuration. These images demonstrate that different triboelectric polymer compositions and bristle diameters can be incorporated into tufted toothbrush heads while preserving a familiar toothbrush architecture.

[0137] Structural fabrication of the triboelectric bristles was further confirmed by microscopy. Fig. 9C shows an SEM image of a representative P(VDF-TrFE) bristle, with a measured diameter of approximately 0.46 mm, confirming successful extrusion and formation of an individual triboelectric filament at the intended submillimeter scale. This image provides direct visual evidence that triboelectric polymers can be processed into discrete bristle elements suitable for toothbrush-head assembly. Results establish hat triboelectric toothbrush heads can be successfully fabricated using multiple triboelectric polymer formulations and bristle dimensions. These prototype results are important because they show that the invention is not limited to isolated fibers or simplified material specimens, but can be embodied as a practical toothbrush system for routine oral use and downstream functional testing.

[0138] Electrical output measurements: The electrical charge measurements confirmed that triboelectric toothbrush prototypes generated measurable brushing-induced voltage, whereas the commercial toothbrush control produced little to no detectable signal under the same experimental conditions. Fig. 10A illustrates the experimental setup used for electrical recording, in which the toothbrush bristles were brushed against a contact surface, while the generated voltage was recorded by the measurement system. This configuration enabled real-time assessment of triboelectric output during simulated brushing.

[0139] Under the Bass brushing technique, the PVDF TriboGlow prototype produced a clear oscillatory electrical signal over time, while the commercial toothbrush remained near theAttorney Docket No. 206017-0315-OOWO

[0140] baseline (Fig. 10B). The PVDF prototype generated repeated positive and negative voltage peaks in the range of a few hundred millivolts, confirming that triboelectric interaction between the bristles and contact surface was sufficient to generate measurable electrical output under clinically relevant brushing motion.

[0141] When the Swivel brushing technique was used, the electrical output of the PVDF TriboGlow prototype increased markedly (Fig. 10C). In this mode, the PVDF prototype produced substantially larger oscillatory voltage amplitudes, reaching values in the range of several thousand millivolts, while the commercial toothbrush again remained near baseline. These results indicate that triboelectric charge generation is strongly influenced by brushing motion, with the Swivel technique producing greater electrical output than the Bass technique for the PVDF -based prototype.

[0142] A similar dependence on brushing technique was observed for the P(VDF-TrFE) bristles. As shown in Fig. 10D, the Swivel technique generated substantially greater electrical output than the Bass technique for the P(VDF-TrFE) TriboGlow prototype. Whereas the Bass condition produced only low-amplitude fluctuations near baseline, the Swivel condition yielded large oscillatory peaks spanning both positive and negative values. These findings further support the conclusion that triboelectric charge generation depends on both bristle composition and brushing mechanics.

[0143] Collectively, Fig. 10 provides direct mechanistic support for the TriboGlow concept by showing that triboelectric bristles act as active functional elements capable of generating measurable electrical charge during brushing. The data further show that the brushing technique can markedly influence the magnitude of the triboelectric response, which may be relevant to downstream ROS generation and whitening performance.

[0144] Whitening assessment (Visual): Representative images of stained teeth before and after treatment are shown in Fig. 11 for the three comparison groups: a commercial toothbrush, the TriboGlow triboelectric toothbrush, and commercially available whitening strips. The stained baseline images are shown in the top row, and the corresponding treated images are shown in the bottom row after the assigned intervention. For the brushing groups, treatment consisted of two hours of simulated brushing, corresponding to approximately 1 month of twice-daily, two-minute brushing.Attorney Docket No. 206017-0315-OOWO

[0145] Visual inspection of Fig. 11 shows that the TriboGlow group exhibited an obvious reduction in brown extrinsic staining and a whiter coronal enamel appearance after treatment relative to the stained baseline. The commercial toothbrush group showed comparatively limited visual improvement, whereas the whitening strips group produced the most pronounced whitening effect. The red-circled regions indicate representative enamel areas used for subsequent color analysis, and the arrows indicate the progression from stained to treated condition within each group.

[0146] These representative images provide direct qualitative support for the whitening efficacy of the TriboGlow prototype. Importantly, the TriboGlow toothbrush produced visible whitening that exceeded conventional brushing with a commercial toothbrush and approached the whitening effect observed with commercial strips after an equivalent 1 -month brushing simulation. Thus, Fig. 11 serves as visual evidence that triboelectric bristles can function as active whitening elements in a realistic toothbrush format.

[0147] Whitening assessment (Quantitative): Quantitative color analysis after two hours of brushing, corresponding to approximately 1 month of twice-daily, two-minute brushing, showed that the TriboGlow P(VDF-TrFE) group produced a significant whitening effect relative to the commercial toothbrush control and remained below the whitening-strip positive control. As shown in Figure 4a, the AE00 values followed the order commercial toothbrush < TriboGlow < whitening strips, with distinct group lettering indicating statistically significant differences among all three treatments (p < 0.05). These results indicate that brushing with the triboelectric P(VDF-TrFE) prototype produced a measurable and significant color change beyond that achieved by conventional brushing alone.

[0148] A similar pattern was observed for the Whiteness Index for Dentistry. As shown in Fig.

[0149] 12B, the AWI D values were lowest for the commercial toothbrush, intermediate for TriboGlow, and highest for whitening strips, again with statistically distinct group lettering (p < 0.05). This result supports the conclusion that the P(VDF-TrFE) TriboGlow prototype increased perceived tooth whiteness beyond the effect of a conventional manual toothbrush, although the whiteningstrip group produced the greatest overall whitening response.

[0150] Taken together, Fig. 12 provides quantitative evidence that triboelectric P(VDF-TrFE) bristles can produce significant tooth-whitening effects after a 1 -month equivalent brushing interval. Importantly, the TriboGlow group consistently outperformed conventional brushing inAttorney Docket No. 206017-0315-OOWO

[0151] both overall color difference (AE00) and dental whiteness (AWI D), supporting the feasibility of using triboelectric bristles as active whitening elements within a realistic toothbrush format Reactive oxygen species: Hydrogen peroxide quantification was first validated using a calibration curve for the colorimetric assay. As shown in Fig. 13A, the assay generated a concentration-dependent response across the tested standard range, supporting its use for quantifying hydrogen peroxide in the brushing samples. This calibration confirmed that the method was suitable for detecting peroxide generated under the simulated brushing conditions used in the TriboGlow experiments.

[0152] Using this calibrated assay, hydrogen peroxide measurements showed that brushing with the PVDF TriboGlow prototype generated measurable peroxide under simulated use conditions. As shown in Fig. 13B, peroxide concentration differed significantly among groups, with the order Commercial 1 month < TriboGlow 1 month < TriboGlow 3 months < Whitening Strips, as indicated by distinct group lettering. Thus, the TriboGlow prototype produced more hydrogen peroxide than the commercial toothbrush control, while remaining significantly below the whitening-strip positive control.

[0153] Importantly, the TriboGlow 3-month brushing-equivalent group produced more hydrogen peroxide than the TriboGlow 1 -month group, suggesting that cumulative brushing exposure increased measurable peroxide generation under the tested conditions. In contrast, the commercial toothbrush showed the lowest peroxide level, supporting the conclusion that peroxide generation was associated with the triboelectric PVDF bristles rather than with brushing alone. Together, these data provide direct chemical support for the proposed mechanism of TriboGlow, namely that triboelectric brushing promotes the generation of whitening-active reactive oxygen species, such as hydrogen peroxide.

[0154] Enamel Surface Roughness After 3-Month Equivalent Brushing with PVDF Bristles: Surface roughness analysis showed that brushing with the PVDF TriboGlow prototype for a 3-month brushing-equivalent interval did not significantly increase enamel roughness relative to the commercial toothbrush control or the pre-treatment baseline. As shown in Fig. 14, the Ra values for the Commercial, TriboGlow, and Before groups shared the same statistical grouping (a), indicating no significant differences among these conditions. In contrast, the whitening strips group exhibited the highest roughness and was statistically distinct (b, p < 0.05)Attorney Docket No. 206017-0315-OOWO

[0155] These findings suggest that the triboelectric PVDF toothbrush did not measurably roughen the enamel surface beyond the level associated with conventional brushing under the tested conditions. The similarity between the TriboGlow and Commercial groups is particularly important because it indicates that the incorporation of triboelectric PVDF bristles did not produce an additional roughening effect despite the active whitening function of the prototype.

[0156] Taken together, Fig. 14 provides preliminary safety evidence that the PVDF TriboGlow prototype can generate whitening-related effects while maintaining enamel surface roughness comparable to that of a conventional manual toothbrush after prolonged simulated brushing. By contrast, the higher roughness observed for the whitening-strip group suggests that the stripbased treatment produced greater surface alteration under the tested conditions.

[0157] SEM Evaluation of Enamel Surface Morphology After Treatment: Scanning electron microscopy provided qualitative support for the surface roughness findings by enabling direct comparison of enamel surface morphology across the tested treatment groups. As shown in Fig.

[0158] 15 A, the untreated enamel surface displayed a relatively smooth background morphology with limited visible topographic disruption. In contrast, the whitening strips group (Fig. 15B) exhibited more pronounced surface irregularities and localized disruption, consistent with greater surface alteration after treatment.

[0159] The commercial toothbrush group (Fig. 15C) showed surface features consistent with mechanical brushing, including visible linear marks and shallow surface texturing. Importantly, the PVDF TriboGlow group (Fig. 15D) exhibited a surface morphology that appeared broadly comparable to that of the commercial toothbrush group, without the pronounced localized disruption observed in the whitening-strip condition. The TriboGlow-treated enamel retained a relatively continuous surface appearance, suggesting that the triboelectric PVDF bristles did not induce major qualitative surface damage beyond that associated with conventional brushing under the tested conditions.

[0160] Taken together, these SEM observations support the profilometry data by indicating that the PVDF TriboGlow prototype did not cause obvious enamel surface deterioration relative to conventional brushing, whereas the whitening strips group showed greater visible surface alteration. Although qualitative in nature, these images provide additional preliminary safety evidence that triboelectric whitening with PVDF bristles may be achieved without marked adverse changes in enamel surface morphology.Attorney Docket No. 206017-0315-OOWO

[0161] In addition to the specific prototypes and data generated to date, the present invention is intended to encompass broader device, material, structural, and method embodiments built around the same triboelectric whitening principle. The central concept is not limited to a single polymer, bristle diameter, brushing motion, or manual toothbrush configuration. Rather, the invention includes any oral-care article in which triboelectric bristles or triboelectric bristlecontaining structures generate localized electrical charge during brushing or related mechanical contact, thereby promoting formation of whitening-active reactive species at or near the tooth surface.

[0162] The disclosures of each and every patent, patent application, and publication cited herein are hereby incorporated herein by reference in their entirety. While this invention has been disclosed with reference to specific embodiments, it is apparent that other embodiments and variations of this invention may be devised by others skilled in the art without departing from the true spirit and scope of the invention. The appended claims are intended to be construed to include all such embodiments and equivalent variations.

Claims

Attorney Docket No. 206017-0315-OOWOCLAIMSWe claim:

1. An oral care device comprising: a head portion comprising cleaning elements, wherein the cleaning elements comprise polyvinylidene fluoride; anda handle attached to the head portion.

2. The oral care device of claim 1, wherein the cleaning elements are selected from the list consisting of bristles, filaments, scrapers, fins, flaps, nodules, pointed structures, polishing cups or pads, textured surfaces, liquid dispensing cavities, and combinations thereof.

3. The oral care device of claim 1, wherein the cleaning elements are bristles.

4. The oral care device of claim 1, wherein the cleaning elements are bristles composed of polyvinylidene fluoride.

5. The oral device of claim 1, wherein the cleaning elements are bristles having a diameter of less than 900 pm.

6. The oral care device of claim 1, wherein the cleaning elements further comprise a polyamide.

7. The oral care device of claim 1, wherein the cleaning elements further comprise poly(vinylidene fluoride-co-trifluoroethylene).

8. The oral care device of claim 1, wherein the cleaning elements are star-shaped bristles.

9. The oral care device of claim 1, wherein the cleaning elements are bristles and the head portion further comprises a plurality of tufts comprising the bristles.Attorney Docket No. 206017-0315-OOWO10. The oral care device of claim 9, wherein the head portion comprises at least one inner row of tufts and at least one outer row of tufts.

11. An oral care device comprising: a head portion comprising cleaning elements, wherein the cleaning elements comprise a triboelectric material; anda handle attached to the head portion;wherein the cleaning elements are configured to produce an electric charge of at least 10 mV when a frictional force is applied by the cleaning elements to a surface of an object in the oral cavity of a subject.

12. The oral care device of claim 11, wherein the cleaning elements are bristles comprising polyvinylidene fluoride.

13. The oral care device of claim 11, wherein the electric charge produced is at least 60 mV.

14. A method of whitening teeth, the method comprising: providing an oral care device comprising cleaning elements, wherein the cleaning elements comprise poly vinylidene fluoride; and contacting an exterior surface of an oral cavity with the cleaning elements such that an electrical charge is generated at the exterior surface.

15. The method of claim 14, further comprising brushing the exterior surface.

16. The method of claim 14, further comprising applying a light energy source.

17. The method of claim 14, wherein the exterior surface is the surface of a tooth.

18. The method of claim 14, wherein the electric charge is at least 10 mV.

19. The method of claim 14, wherein the electric charge produces hydrogen peroxide.

20. The method of claim 14, wherein the brushing cleans the exterior surface

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