Patent Description:
Cleaning of teeth of humans and animals is a prerequisite for oral health, and health of internal organs. Various dental cleaning devices are available, such as manual and powered toothbrushes. With these typical toothbrushes, it is advised to brush the teeth by a prescribed method for at least two minutes per day to effectively remove plaque. Yet, an average person does not spend all of the prescribed time cleaning his or her teeth, and does not always brush according to an effective method. Additionally, for disabled or elderly persons or children it can be difficult to brush the teeth with a toothbrush, since typical toothbrushes require precise positioning of the brush bristles on various surfaces of the teeth.

In case at some or all dental positions teeth are missing as is frequently the case with elderly persons, cleaning of the gum at these dental positions is still a prerequisite for oral health, and health of internal organs.

There is a need to automatically brush the teeth and/or gum at the dental positions for cleaning the teeth and/or gum at these dental positions, whereby the time and effort required for effective brushing is reduced. In addition, there is a need to avoid carefully manoeuvring the brush.

Dental cleaning devices are known comprising mouthpieces which cover the maxillary dental arch and/or the mandibular dental arch. These mouthpieces may be of the type comprising a body provided with at least one recess delimited by a recess wall lined with a plurality of bristles extending from the recess wall into the recess, the recess wall defining a U-shaped length axis and, viewed transverse to the length axis, a U-shaped cross-sectional shape and being configured for encompassing a plurality of dental positions along a dental arch. The dental positions, like teeth and/or gum, to be brushed are inserted in the at least one recess and the recess wall lined with bristles is operated to brush the teeth and/or gum with the bristles on the recess wall. Depending on the length of the recess several or all dental positions of the maxillary dental arch and/or the mandibular dental arch may be brushed simultaneously. An example of such a mouth piece can be found in <CIT> or <CIT>.

A part of such a mouthpiece is the recess wall lined with bristles, which recess is in length direction U-shaped and has transverse to this length direction a U-shaped cross-section, and which has the bristles at the inner side of the recess. The small inner space of the U-shaped cross-section and the arch-shaped length make the manufacturing of such a recess wall lined with bristles quite difficult. Of course such a recess wall lined with bristles can be made manually by attaching the bristles or tufts of bristles one by one to the recess wall. This is however labour intensive and not time and cost efficient. Such a recess wall with U-shaped cross-section and bristles on the inner side of the recess may further be made by injection moulding the recess wall and bristles simultaneously, but, due to the small inner width of the U-shape, unloading the moulded recess wall and bristles from the mould is not possible or quite difficult to deal with without damaging the moulded product.

Further problems with such mouthpieces of the type according to <CIT> and <CIT> or according to other designs like for example shown in <CIT>, <CIT>, <CIT>, are amongst others:.

Thus there is a need for a method of manufacturing a mouthpiece for simultaneously brushing at a plurality of dental positions, wherein the mouthpiece is of the type comprising a body having a recess lined with bristles, which recess has a J-shaped or U-shaped length direction and a U-shaped cross-section transverse to the length direction and is configured for encompassing a dental arch of multiple dental positions, and wherein the at least one bristle carrier delimits the recess.

It is an object of the invention to provide an alternative method of manufacturing a mouthpiece for simultaneously brushing at a plurality of dental positions, wherein the mouthpiece is of the type comprising a body having a recess lined with bristles, which recess has a J-shaped or U-shaped length direction and an at least partly U-shaped cross-section transverse to the length direction and is configured for encompassing a dental arch of multiple dental positions, and wherein the at least one bristle carrier delimits the recess. A further object of the invention is to provide such a method overcoming one or more of the above problems associated with the manufacturing of such mouthpieces.

These objects are addressed by a method of manufacturing a bristled pad as defined in claim <NUM>, a method of manufacturing a mouthpiece as defined in claim <NUM>, a bristled pad as defined in claim <NUM>, a mouthpiece as defined in claim <NUM> and a dental cleaning device as defined in claim <NUM>.

According to an examplary first aspect of the description, a method of manufacturing a mouthpiece for simultaneously brushing at a plurality of dental positions is disclosed, the mouthpiece being of the type comprising a body defining a recess which is lined with bristles and has a J-shaped or U-shaped length direction and an at least partly U-shaped cross-section transverse to the length direction (the cross-section may be partly U-shaped, because, for example at the incisors, the bottom of the U-shape may be open or V-shaped);.

The method according to the examplary first aspect basically comprises three main steps. Each main step may comprise further sub-steps, some of which will be discussed further below.

The main steps are manufacturing a bristled pad - called the pad manufacturing step -, a body providing step in which the body is provided, and a pad attaching step wherein the bristled pad is attached to the body. According to a further embodiment of the examplary first aspect, the prefabricated foil may be manufactured in the pad providing step, such as about simultaneously with fusing the bristles to the prefabricated foil. This may for example be done by extruding or injection moulding the foil over the fixed ends of the bristles, in which use is made of the foil still being in a hot condition enabling it to be fused with the fixed ends of the bristles. According to an alternative or supplementary other further embodiment of the examplary first aspect, the body may be manufactured in the providing step.

The bristled pad may already have been made before the body providing step. The bristled pad may be attached to the body after the body providing step. In case the body is manufactured in the body providing step, the bristled pad may also be attached to the body during the body providing step. The bristled part may for example be adhered with an adhesive to the bristle carrier. Attaching the bristled pad to the body during the body providing step may according to a specific embodiment of the examplary first aspect considerably facilitate integrating the pad as integral part of the body. An example of attaching the bristled pad during the body providing step, is integrating the pad into the body during injection moulding the body or part of the body. The pad may be a pre-fabricated insert and may be placed in the mould before injecting the injection moulding material for moulding (at least part of) the body so that after hardening of the injection moulding material the pad is integrated with or in the injection moulding material. The bristled pad may also be made during, such as simultaneously with, or after the body providing step. When the bristled pad is made after the body providing step, the pad attaching step will take place after the body providing step as well. In this case the pad attaching step may be a step in which two pre-fabricated parts (the bristled pad and the body or part of the body) are assembled together. As will be clear to the skilled man, it is also conceivable that the pad attaching step is a step in which two pre-fabricated parts are assembled together in case the bristled part is manufactured before or during manufacturing of the body.

According to the examplary first aspect, the pad is a bristled pad consisting of a foil and bristles projecting from a front surface of the foil. The back surface of the foil opposite the front surface is essentially flat. In fact, according to a further embodiment of the examplary first aspect, the pad is made by assembling together only two components: a pre-fabricated foil and pre-fabricated bristles, such as tufts of bristle hairs/fibers. The foil is pliably, i.e. supple bending, so that it can easily follow the curvatures of the recess - the curvature due to the J-shaped or U-shaped length direction of the recess and/or the curvature due to the U-shaped cross section of the recess - and therefore has a thickness of at most <NUM>. Such a thickness also does not use much space in the mouthpiece. Further the fixed ends of the bristles - i.e. the ends opposite the free ends of the bristles projecting into the recess of the mouthpiece to be manufactured - are fused to the foil, in other words attached to the foil by fusing the fixed ends of the bristles and the foil. This results in a bristled pad made from assembling a foil and bristles. Due to the fused connection the connection between bristles and foil is strong. Due to the pliability of the foil it is easy to attach the pad into the recess whilst the back surface of the foil follows the shape of the surface of the bristle carrier to which it is attached. Due to the small thickness of the foil, a significant increase in mouthpiece dimension is prevented.

According to a further embodiment of the examplary first aspect, the thickness of the prefabricated foil is at most <NUM>, or at most <NUM> such as at most <NUM>. According to another further embodiment of the first aspect, the prefabricated foil has a thickness of at least <NUM> in order to ensure the foil to be sufficient strong. Taking into account the presently anticipated fusing techniques, it seems that the prefabricated foil may have a thickness in the range of <NUM>-<NUM>, such as in the range of <NUM>-<NUM>, whilst still providing sufficient retention force to prevent on the one hand bristles from separating from the foil and on the other hand foil parts with bristles from separating from the rest of the foil due to locally tearing or breaking of the foil.

When fusing the bristles with (or to) the prefabricated foil, the thickness of the foil may increase due to melt originating from the fixed ends of the bristles. Taking this into account, the examplary first aspect may in addition or alternatively be defined in terms of thickness of the foil of the bristled pad, i.e. the foil after fusing it with the bristles:.

According to another further embodiment of the exemplary first aspect of the description, the pliable foil of the bristled pad has a bending resistance of less than <NUM> Newton - such as less than <NUM> Newton or less than <NUM> Newton -, the bending resistance being defined as the force F required to bend a strip of foil having a width W of <NUM> and length L of <NUM> over a distance Q of <NUM>, the force F being directed in the direction opposite to the direction in which the free ends of the bristles are facing. As follows from the low force in this bending resistance, the foil will easily adapt itself to the surface of the bristle carrier to which it is attached. This facilitates not only the pad attachment step, but also adaptation of the foil to the shape of the teeth of the user.

According to another further embodiment of the exemplary first aspect of the description - in which the mouthpiece to be manufactured has two said recesses, the J-shaped or U-shaped length directions of both recesses extending parallel and the U-shaped cross-sections of both recesses opening in mutually opposite direction - the body providing step comprises providing a body with two said recesses, the J-shaped or U-shaped length directions of both recesses extending parallel and the U-shaped cross-sections of both recesses opening in mutually opposite direction, each said recess having at least one bristle carrier delimiting the respective recess; and the pad attaching step comprises attaching one or more said pads to the at least one bristle carrier of each said recess. A mouthpiece with two such recesses allows simultaneously cleaning of the dental positions (with or without teeth) of the maxillary dental arch and the mandibular dental arch.

The bristles may according to the exemplary first aspect of the description be made from materials that are frequently used for bristles of toothbrushes because of their stiffness, bend recovery, chemical resistance and abrasive resistance. These materials which according to the invention may be used for the bristles comprise the following plastics: polyamide (PA), such as all types of nylon like PA6, PA66, PA610, PA612, PA11, PA12; polyethylene terephthalate (PBT); polypropylene (PP); polyester (PE); Polystyrene (and styrene copolymers) (PS); polyurethane (PU), amongst which TPU; polyvinylidene chloride (PVC); and TPE. According to a specific embodiment of the exemplary first aspect of the description, the bristles comprise polybutylene terephthalate (PBT) or polyamide (PA) fibers, such as nylon fibers. Bristles of these materials have properties providing good cleaning action when brushing the teeth. The bristles are stiff (relatively large bending resistance) which contributes in the scrapping action of the free ends of the bristles.

According to another further embodiment wherein the bristles comprise fibers of a first material and wherein the front surface side of the foil, also called the bristled surface side of the foil, comprises a second material fusible with the first material. The second material may, according to a further embodiment of the exemplary first aspect of the description, be similar - but not necessarily identical - to the first material. The second material may according to a further embodiment be a polybutylene terephthalate (PBT) or polyamide (PA), such as nylon. As an example of the first material being similar - but not identical - to the second material, nylon may be mentioned as first material for the bristles and polyamide for the second material of at least the front surface of the foil. The foil may be made of one material or multiple materials. The foil may comprise for example two or three layers of different material.

According to another further embodiment of the first aspect of the invention the foil of the pad is fused with the bristle carrier in the pad attaching step. The bristle carrier and pad, more precisely the foil of the pad, then become so to say one integral part, which further improves the retention force against bristles from separating from the body.

According to another further embodiment of the exemplary first aspect of the description, the bristle carrier is of a third material not-fusible with the bristles and/or the front surface of the foil, wherein the foil comprises a first outer layer of a material fusible with the bristles and a second outer layer of a fourth material fusible with the third material. In case of the embodiment in which the bristles are of a first material and the front surface side of the foil, also called the bristled surface side of the foil, comprises a second material fusible with the first material, this means that the bristle carrier is of a third material not-fusible with the first material and/or second material, and that the foil comprises a first outer layer of the second material and a second outer layer of a fourth material fusible with the third material. In these further embodiments, the foil is multi-layered with the first outer layer at the front surface of the foil and the second outer layer at the back surface of the foil. The first and second outer layer may be directly joined to each other, or one or more intermediate layers may be provided between the first and second outer layer. The foil with said first outer layer configured to be fusible with the bristles and said second outer layer configured to be fusible with the bristle carrier, allows attachment of bristles to the carrier by fusing materials together from a material in cases in which the bristles and carrier are from a materials which do fuse together not or which when fused together do not provide a reliable attachment.

The fourth material may, according to a further embodiment of the exemplary first aspect of the description be similar - but not necessarily identical - to the third material. According to another further embodiment of the exemplary first aspect of the description, the fourth material is a polypropylene (PP), a polyethylene (PE), a thermoplastic elastomer (TPE), or a thermoplastic polyurethane (TPU).

The third material may be a polypropylene (PP), a polyethylene (PE), a thermoplastic elastomer (TPE), or a thermoplastic polyurethane (TPU).

As an example of the fourth material being similar - but not identical - to the third material, TPE may be mentioned as material for the carrier and PP may be mentioned as material for the second outer layer of the foil.

According to another further embodiment of the exemplary first aspect of the description, the bristle carrier comprises a polypropylene (PP), a thermoplastic elastomer (TPE), or a thermoplastic polyurethane (TPU).

According to another further embodiment of the exemplary first aspect of the description, the foil is of a non-elastic material and/or an essentially inextensible material.

According to another further embodiment of the exemplary first aspect of the description, the bristle carrier is of a flexible, elastic material.

According to another further embodiment of the exemplary first aspect of the description, the body further comprises at least part of a driving system configured for moving, such as reciprocatingly moving, the bristles provided in the recess with respect to the rest of the body. The reciprocating movement assists in cleaning the dental positions.

According to another further embodiment of the exemplary first aspect of the description, the body comprises a pressure chamber or chain of pressure chambers extending along the length of the recess - such as along the full length of the recess -, wherein the wall of the pressure chamber at the side of the recess defines the bristle carrier, wherein the pressure chamber is configured for containing a fluid under pressure; and wherein the body is configured to move the bristle carriers to and fro with respect to the recess by reciprocatingly increasing and decreasing a pressure in the pressure chamber or chain of pressure chambers between a decreased pressure condition and an increased pressure condition. A chain of pressure chambers is understood to be chain extending along the J-shaped or U-shaped length direction, the chain comprising a multiple of - viewed in said J-shaped or U-shaped length direction - aligned pressure chambers.

According to another further embodiment of the exemplary first aspect of the description, the pad manufacturing step comprises the following steps:.

The heating of step d) may be by means of plastic welding, such as hot gas welding, heat sealing, hot plate welding, infrared welding, high frequency welding, induction welding, ultrasonic welding, friction welding, spin welding, laser welding, or a combination of one or more of these plastic welding techniques. In hot plate welding a so called heat stamp is used, which is a heated or hot body which is pressed against the bristles and/or foil to cause melting. Step d) may take place after or before step c).

According to another further embodiment of the exemplary first aspect of the description, step a) may comprise the steps of:.

According to an exemplary second aspect of the description, a mouthpiece obtained with the method according to the exemplary first aspect of the description is provided.

According to an exemplary third aspect of the description, one or more of the objects of the invention are achieved by providing a method of manufacturing a bristled pad consisting of a pliable foil, such as a plastic foil, and bristles, such as plastic bristles, projecting from a front surface of the foil, and the foil having a back surface opposite the front surface;
wherein the method comprises the following steps:.

According to a further embodiment of the exemplary third aspect of the description, the bristled foil may have a thickness of at most <NUM>, such as at most <NUM> or at most <NUM>.

According to a further embodiment of the exemplary third aspect of the description, step a) may comprise the steps of:.

According to a further embodiment of the exemplary third aspect of the description, the heating of step d) may be by means of plastic welding, such as hot gas welding, heat sealing, hot plate welding, infrared welding, high frequency welding, induction welding, ultrasonic welding, friction welding, spin welding, laser welding, or a combination of one or more of these plastic welding techniques.

According to a still further embodiment of the exemplary third aspect of the description, step d) may take place after or before step c).

According to a still further embodiment of the exemplary third aspect of the description, the pliable foil of the bristled pad has a bending resistance of less than <NUM> Newton - such as less than <NUM> Newton or less than <NUM> Newton -, the bending resistance being defined as the force F required to bend a strip of foil having a width W of <NUM> and length L of <NUM> over a distance Q of <NUM>, the force F being directed in the direction opposite to the direction in which the free ends of the bristles are facing.

According to an exemplary fourth aspect of the description, a bristled pad obtained with the method according to the exemplary third aspect of the description is provided. According to a further embodiment of the exemplary fourth aspect of the description, the mouthpiece has two said recesses, the J-shaped or U-shaped length directions of both recesses extending parallel and the U-shaped cross-sections of both recesses opening in mutually opposite direction.

According to a still further embodiment of the exemplary fourth aspect of the description, the body comprises a pressure chamber or chain of pressure chambers extending along the length of the recess, wherein the wall of the pressure chamber at the side of the recess defines the bristle carrier, wherein the pressure chamber is configured for containing a fluid under pressure; and wherein the body is configured to move the bristle carriers to and fro with respect to the recess by reciprocatingly increasing and decreasing a pressure in the pressure chamber or chain of pressure chambers between a decreased pressure condition and an increased pressure condition.

According to an exemplary fifth aspect of the description, a dental cleaning device comprising a mouthpiece according to the exemplary fourth aspect of the description and a pressure and/or suction device which is configured to be in fluid communication with the pressure chamber or chain of pressure chambers and configured for reciprocatingly increasing and decreasing the pressure in the pressure chamber are provided.

In this application the term 'pliable' in relation to the foil is used in the meaning of supple so that it is able to bend freely and repeatedly without breaking. It may for example be a foil, like the foil of a sandwich bag, which already bends or even - when kept horizontal - tends to assume a vertical position under influence of its own weight. It may also be a foil which has a stiffness enough to allow it be kept horizontal, but bendable under influence of small forces.

In this application the term 'bristled' used as an adjective before a noun like part, pad, foil, or carrier means a part, pad, foil, or carrier, respectively, provided with bristles. In this application the term 'bristle' or 'bristles' is used to indicate a single bristle hairs or fibers as well as to indicate tufts of bristle hairs or bristle fibers.

In this application the term 'fixed end' of a bristle (or tuft or bristle fiber) is used to indicate one of the ends of the bristle, namely which is - depending on the stage in manufacturing of the bristled pad - (still) to be fixed or is (already) fixed to the pliable foil. The term 'fixed end' does not say that, in case of for example a tuft, these ends of the bristle fibers of the tuft are mutually fixed. The fixed ends of the bristle fibers of a tuft may or may not be mutually fixed. For example, after manufacturing the bristled pad, the fixed ends of the bristled fibers of a tuft may in general be mutually being fixed due to fusing together, but, in the stage before fusing the fixed ends to the foil, the fixed ends of the bristle fibers of a tuft may, although combined in a tuft, not yet be attached to each other. However, it is according to the invention conceivable that the so called fixed ends of the bristle fibers in a tuft are already attached to each other in the stage before fusing the fixed ends to the foil.

Summarizing, the present description relates thus relates to the manufacturing of a bristled pad for a mouthpiece toothbrush, a bristled pad, the manufacturing of a mouthpiece toothbrush with such a bristled pad, and a mouthpiece toothbrush. The bristled pad is manufactured from a prefabricated foil and prefabricated bristles. The prefabricated bristles are attached to the prefabricated pliable foil of at most <NUM> by fusing the fixed ends of the bristles with the foil, which results in a pliable bristled pad. In the method of manufacturing the mouthpiece, the pliable, bristled pad is attached to the body of the mouthpiece.

The invention will be explained further with reference to the drawings. In these drawings:.

<FIG> shows in perspective view, highly schematically a part of an upper dental arch <NUM> with dental positions <NUM>-<NUM>. Each dental position is indicated with a vertical dashed line. Each dental position usually comprises a tooth which is named according to a nomenclature known to each dentist. Using this nomenclature:.

In <FIG> the dental position of the right 'second molar' is not shown, and also the dental positions of the right and left 'third molar', also called wisdom tooth, are not shown. Similar the lower jaw has a similar number of dental positions, which are in accordance with said nomenclature similarly named.

Reference number <NUM> indicates the lingual side of the arc of dental positions. The lingual side <NUM> is the inner side of the arc of dental positions, which inner side faces the tongue. Reference number <NUM> indicates the facial side of the arc of dental positions. The facial side <NUM> is the outer side of the arc of dental positions, which outer side faces the face, like the cheeks and lips.

<FIG> further shows a system of three mutually orthogonal axes, comprising an x-axis X, an y-axis Y and a z-axis Z. The z-axis Z is a curved axis following the contour of the dental arch <NUM>. The x-axis X and y-axis Y are perpendicular to each other and define an xy-plane which is essentially flat and perpendicular to the dental arch <NUM>, i.e. each xy-plane intersecting a location on the z-axis is, at that location, perpendicular to the curved z-axis Z. The z-axis Z defines a curved length direction. The z-axis Z and y-axis Y define a curved zy-plane, with viewed along the z-axis, an arc-shape similar to shape of the dental arc. Further, the z-axis Z and x-axis X define a zx-plane and the x-axis X and y-axis Y define an xy-plane.

Referring to the terms 'J-shaped or U-shaped length direction' and 'U-shaped cross-section' as used in the claims, the 'J-shaped or U-shaped length direction' is associated to the U-shaped z-axis Z in <FIG> and the 'U-shaped cross-section' is associated with the xy-plane in <FIG>.

<FIG> shows schematically a perspective view of an example of a so called full mouthpiece <NUM> made with the method according to the invention. <FIG> shows schematically a cross section of the mouthpiece of <FIG>, viewed as indicated by arrows IIb in <FIG>.

The full mouthpiece <NUM> comprises a body <NUM> provided with a first recess 22a. This first recess 22a has, viewed along the z-axis of <FIG>, an U-shaped length direction and, viewed in the xy-plane of <FIG>, an U-shaped cross section. The first recess 22a is delimited by a recess wall <NUM>, which is in the xy-plane U-shaped. The recess wall <NUM> is lined with a plurality of bristles <NUM>. The bristles shown in <FIG> are tufts <NUM> of bristle fibers <NUM>. The bristle fibers may for example be a PA fibers, such as a nylon fibers, or a PBT fibers, or a mixture of these fibers. But also fibers from other materials or mixture of fibers from other materials with or without fibers of PA, such as nylon, and/or PBT are conceivable. Each bristle, such as tuft of fibers, has one end, called the fixed end <NUM>, attached to the recess wall <NUM> and extending from the recess wall <NUM> into the first recess 22a.

Reference <NUM> indicates a nipple configured for connecting the mouthpiece to a pumping and/or suctioning device. The mouthpiece <NUM> further has a right half <NUM> and a left half <NUM>, which halves come so to say together at nipple <NUM>.

Reference <NUM> indicates an imaginary curved dividing line, which defines a mirror plane parallel to the xz-plane as defined in <FIG>. The mouthpiece as shown in <FIG> is so to say about mirror symmetrical with respect to this mirror plane, meaning that there is a second recess 22b (not visible in <FIG> but visible in <FIG>) opposite the first recess 22a, which second recess 22b is lined with bristles as well. It is noted that the first recess 22a may have a shape different than the shape of the second recess 22b because the (teeth of the) upper and lower arc of dental positions have different shapes. The term 'mirror symmetrically' above thus is not used in the strict mathematical sense but just in the sense that there are two recesses, each on one side of the mirror plane.

The recesses 22a, 22b are configured to encompass an entire dental arch from the dental position of the right second or first molar to the dental position of the left second respectively first molar. The recesses 22a, 22b may also be configured to encompass a larger or smaller part of an arch of dental positions.

<FIG> shows a cross-section according to arrows IIb in <FIG> of a right part of the mouth piece <NUM>.

As can best be seen in <FIG>, the bristles may be provided as tufts <NUM> of relatively thin bristle fibers <NUM>. Further, it can be seen in <FIG> that the bristles are provided on bristled pads consisting of a foil 36a, 36b and bristles fused with the foil 36a, 36b. The foil in the example of <FIG> is a multi-layer foil with a first outer layer 36a and a second outer layer 36b.

As can be seen in <FIG>, the mouthpiece <NUM> has a body <NUM> having in its upper side a first recess 22a and in its lower side a second recess 22b. Both recesses 22a, 22b are delimitated by a flexible recess wall <NUM>. In cross-section parallel to the xy-plane as defined in <FIG>, the recess walls <NUM> are U-shaped and have a recess wall bottom <NUM> and two recess wall legs <NUM> extending from the recess bottom wall. The recess wall <NUM> is covered with tufts <NUM> of bristle fibers <NUM> on the legs <NUM> and/or bottom <NUM> of the recess wall <NUM>.

Inside the body there is provided a pressure chamber <NUM>, which may, via the nipple <NUM> (<FIG>), be filled with a fluid. The fluid may be a gas, like air, or a liquid, like water. In the embodiment as shown in <FIG>, the mouthpiece has one pressure chamber. It is however noted that the mouthpiece may comprise a plurality of pressure chambers, like <NUM> pressure chambers, or any other number of pressure chambers. <CIT> shows examples of other numbers of pressure chambers in <FIG>, <FIG>, <FIG> and <FIG>. In case of multiple pressure chambers, all the pressure chambers or groups of pressure chambers may according to the invention be in fluid communication with each other, similar as is described in <CIT>. Viewed in the U-shaped length direction (i.e. along the z-axis of <FIG>), a chain of so to say aligned pressure chambers may be provided as well.

As can be seen in <FIG>, the mouthpiece may comprise an internal support structure of a material which is rigid relative to the material of the recess wall <NUM>. This support structure may structure comprise a lingual plate <NUM> and a facial plate <NUM>, both extending essentially parallel to the curved zy-plane defined in <FIG> and consequently, viewed along the z-axis, having a U-shape. In order to keep the lingual plate <NUM> and facial plate <NUM> at a distance from each other, the support structure may comprise one or more spacers <NUM>. These one or more spacers <NUM> may for example be a multiple of bars or wires or a single plate which may extend essentially parallel to the zx-plane as defined in <FIG>. In case of a single plate as spacer, this plate may divide the pressure chamber <NUM> in two pressure chambers, an upper one and a lower one. These two pressure chambers may be in fluid communication with each other via one or more through holes through the plate. In case of large through holes and/or a large number of through holes the two pressure chambers may effectively be one single pressure chamber.

The mouthpiece as shown in <FIG> is configured for simultaneously brushing at a plurality of dental positions. In case a tooth is present, the tooth of the respective dental position will be brushed. The remnants at a dental position, like the gum, may be brushed in case a tooth may be missing and the teeth adjacent the location of the missing tooth may be additionally brushed by bristles intended for the location of the missing tooth.

The single pressure chamber <NUM> comprises a first flexible recess wall <NUM> delimiting the first recess <NUM> (the upper one in <FIG>) and a second flexible recess wall <NUM> delimiting the second recess <NUM> (the lower one of <FIG>). The first and second recess walls are deformable, in particular by increasing or decreasing the pressure in the pressure chamber <NUM>. The flexible recess walls <NUM> may be made from an elastic material, such as a rubberlike material. The flexible recess walls <NUM> may also be made from a non-elastic material. Examples of suitable materials for the recess wall are PP, a PE, a TPE, a TPU. The material of the flexible recess walls <NUM> may keep a predetermined shape when there is substantially no, or a low, pressure difference across an inner side and an outer side of the flexible recess walls <NUM>.

The mouthpiece <NUM> is configured for the tufts <NUM> to engage the tooth surface of teeth of a dental arch or, in case one or more dental positions the tooth might be missing, to engage the gum at the respective dental position(s) at least when the pressure in the pressure chamber <NUM> is increased. In case a tooth might be missing at a dental position, especially the tufts <NUM> at the free ends of the recess wall legs <NUM> will engage the gum at the empty dental position.

Viewed in length direction Z of the dental arch - as defined in <FIG> -, the tufts <NUM> of bristle fibers <NUM> may be arranged at about the same density as viewed in the cross-sections shown in <FIG>.

<FIG> shows that at dental location of the incisors the bottom of the U-shaped recess 22a and 22b may in fact be open (or, not showen, V-shaped). In this 'open embodiment', the first recess 22a and second recess 22b are in open connection with each other. To prevent the lingual side <NUM> of the body and the facial side <NUM> of the body from widening away from each other, some spacer <NUM> may still be provided at the dental position of the incisors, but this spacer <NUM> may also be left away.

When the pressure in the pressure chamber <NUM> is in increased to an increased pressure condition, for example by feeding a fluid to the pressure chamber <NUM>, or increasing an amount of fluid in the pressure chamber <NUM>, the recess walls <NUM> are so to say compacted to narrow the recess <NUM>, whereby the bristles <NUM>,<NUM>, in particular the free ends thereof, may engage tooth surfaces firmly and/or may be deformed against tooth surfaces. When the pressure in the pressure chamber <NUM> is decreased subsequently, the recess walls are so to say widened to enlarge the recess <NUM>. This narrowing and widening of the recess walls may be small, but when alternatingly repeated with some frequency of for example <NUM> to <NUM>, this alternatingly deforming of the recess wall by alternatingly narrowing and widening it, causes the bristles to move between a firmer and relatively less firm engagement with tooth surfaces and/or the bristles to alternate between a first and second deformed condition, which in turn causes a sweeping and/or rubbing of bristles along the tooth surfaces.

By a suitable cycle of increasing and decreasing pressure in the pressure chamber <NUM> an effective brushing action of the mouthpiece can be obtained. The bristles <NUM> attached to the recess wall bottom <NUM> generally perform an upward and downward motion during such cycling, and the bristles <NUM> at the recess wall legs <NUM> generally perform a sideways motion to and fro during such cycling in the direction of the x-axis as defined in <FIG>. Due to the recess 22a, 22b alternatively narrowing and widening when alternatingly increasing and decreasing pressure, the bristles <NUM> at the recess wall legs may also be subjected to a back and forth pivoting around the z-axis as defined in <FIG>, resulting in a sweeping and/or rubbing movement of the bristles in the direction of the y-axis as defined in <FIG>.

Referring to <FIG>, the width of a teeth element in the X direction varies, depending on the dental position between about <NUM> to <NUM>. Taking into account hat t is desired to keep the mouthpiece as small as possible, the width of the recess in the X direction is to be kept as small as possible and may be about <NUM> to <NUM> wider than the width of the respective tooth. The bristles may be <NUM> to <NUM> long, meaning that between the bristles extending from opposing recess wall legs <NUM> no interspace or a limited amount of interspace of about <NUM>-<NUM> is left. In <FIG>, these interspaces are shown exaggerated. This limited amount of interspace makes it difficult to manufacture a mouthpiece as shown in <FIG> in economical manner. Injection moulding for example is difficult due to the bristles extending from the opposing recess wall legs extend essentially in the X direction which is transvers to the direction in which injection moulding moulds may be separated from each other after moulding. <FIG> shows a so called half mouthpiece <NUM>. The difference with the mouthpiece of <FIG> is basically that the right half of <FIG> has been left away, resulting in a J-shaped, half mouthpiece. With a J-shaped half mouthpiece, all dental positions of the right half of the dental positions can be cleaned in one go. After taking the mouthpiece out of the mouth, turning it around and inserting it in the mouth again, also the left half of the dental positions can be cleaned (or vice versa, first cleaning the right half and then the left half). The half mouthpiece also comprises a body <NUM> provided with a first recess 22a and 22b, however, the first recess 22a and second recess 22b have, viewed along the z-axis of <FIG>, an J-shaped length direction and, viewed in the xy-plane of <FIG>, an U-shaped cross section.

For the rest, the mouthpiece of <FIG> is basically the same as the mouthpiece of <FIG>, except that in <FIG> the foil <NUM> of the bristled pad is a foil of one layer, whilst in the embodiment of <FIG> the foil has two (or more) layers, a first outer layer 36a and a second outer layer 36b. It is however to be noted that in the embodiment of <FIG> also bristled pads with single layer foil can be used and that in the embodiment of <FIG> also bristled pads with multi-layer foils can be used. Moving the bristles to and fro with respect to the recess(es) is realised by means of a drive system, at least part of which is arranged in the mouthpiece. The drive system may be a mechanical system causing movement of the bristles. An example of a mechanical drive system is shown in <FIG> can be considered as a variant of <FIG> can be considered as a variant of <FIG>. In this embodiment the body with mechanical drive the body may for example be a solid mass <NUM> in which a vibration element <NUM> is provided as part of the drive system. This vibration element may be set into vibration by a handle mounted at <NUM> with a vibrating interface, which interface in turn is set into vibration by a motor provided in the handle. Now returning to the embodiment shown in <FIG>, the drive system for moving the bristles to and fro with respect to the recess(es) is realized by increasing and decreasing the pressure in the pressure chamber <NUM>, which is effected by a pump unit. Different pump unit and valve combinations are possible. One possible embodiment is by way of example explained with reference to <FIG>.

<FIG> schematically depicts, in a partially cut-away perspective view, a dental cleaning device <NUM> comprising a handle member <NUM> and a mouthpiece <NUM> coupled thereto, e.g. a mouthpiece as described in the above. The handle member <NUM> is provided with a handle interface <NUM>, and the mouthpiece <NUM> is provided with a mouthpiece interface <NUM> configured to be detachably coupled to the handle interface <NUM>. The handle member <NUM> comprises a battery <NUM> for storing electrical energy which can be fed to the battery <NUM> through a battery charging interface <NUM>. The battery <NUM> provides energy to a printed circuit board, PCB, <NUM>, to a pump unit comprising a motor <NUM>, a transmission <NUM>, a crank piston <NUM> and a piston pump <NUM>, and to optionally a mouthwash pump <NUM>. A mouthwash capsule <NUM> containing a mouthwash liquid may be removably accommodated in the handle member <NUM>. The piston pump <NUM> may be a pneumatic pump. Instead of a piston pump also a diaphragm pump, a plunger pump, a membrane pump, or bellows pump may be used. The mouthwash pump <NUM> may be a hydraulic pump.

<FIG> serves the purpose of illustrating the definition of the term 'bending resistance' as it is used in the claims as well as the description of this application. Black rimmed in gray a sample strip of foil is shown. As shown, this sample strip has a width W and a length L. The sample strip is fixed at its left end A and extends from A horizontally to the right without any support. The sample strip thus represents a so called 'cantilever beam'. When a downward force F is exerted on the right end of this sample strip/cantilever beam, the strip/beam will deflect to a deflected condition, which is shown in dashed line in <FIG>. In deflected condition, the right end of the strip/beam lies a vertical distance Q below the right end of the strip/beam in unloaded condition. The bending resistance of the foil is in this application defined in terms of a distance Q which a sample strip of foil having predetermined dimensions W and L bends upon exerting a predetermined force F transverse to the foil. The force F is in this definition directed in the direction opposite to the direction in which the free ends of the bristles are facing. This direction of the force F means that the foil is bended such that the bristles are on the convex side of the bended foil, as is indicated by the in this example four bristles shown in <FIG>. Doing so, the bending resistance of the pliable foil is defined as X Newton, when a force F of X Newton is required to bend a strip of said foil having a width of <NUM> and a length of <NUM> over a distance Q of <NUM>, the force F being directed in the direction in which the free ends of the bristles are facing. The definition illustrated in <FIG>, may be used in similar manner to define the stiffness of a bristle fiber for example as follows: 'the fiber having a stiffness of X Newton, when a force F of XNewton is required to bend a bristle fiber having a length of <NUM> over a distance Q of <NUM>'.

<FIG> shows two bristled pads <NUM> according to the invention. The pad <NUM> on the left is in flat condition and the pad <NUM> on the right is in a bended condition. Referring to the definition of 'bending resistance' as elucidated in <FIG>, also the bended pad on the right of <FIG> has its bristles on the convex side. However, it is to be noted that the pad may also be bended in opposite direction, as is for example shown in <FIG>, see the bristled pads <NUM> respectively <NUM>.

As shown in <FIG>, the bristled pad <NUM> according to the invention consists of a pliable foil <NUM> with tufts <NUM> of bristle fibers. The foil <NUM> may have a thickness T of <NUM>-<NUM>. Further the bending resistance of the foil may for example be less than <NUM> Newton or even less than <NUM> Newton. The foil <NUM> has a front surface <NUM> from which the bristles (tufts) project. Opposite the front surface the foil <NUM> has a back surface <NUM>. Each bristle has a fixed end <NUM> where the bristle <NUM> is fused to the foil <NUM> and a free end <NUM> facing away from the foil.

<FIG> shows two bristle pads <NUM>, <NUM> which, in cross section transverse to <FIG>, may be in accordance with <FIG>. The bristled pads <NUM>, <NUM> are in this example in the form of elongate bristled strips, a first strip <NUM> and a second strip <NUM> which is - as can be seen good in <FIG> - a little shorter than the first strip <NUM>. <FIG> shows both bristled strips in a flat condition and <FIG> shows both strips in a bended condition as they may have when attached in the body (not shown) of the mouthpiece. The longer strip <NUM> is to be attached to the facial side - i.e. the outer side - of the recess and the shorter strip is to be attached to the lingual side - i.e. the inner side - of the recess. Referring to the embodiment of <FIG>, the strips <NUM> and <NUM> are to be attached to the flexible recess wall <NUM>, strip <NUM> on one of the wall legs <NUM> and strip <NUM> on the opposing wall leg <NUM>. The strips <NUM> and <NUM> may be attached to the recess wall <NUM> by fusing the strips along their back surface <NUM> onto the recess wall <NUM>. This may for example be achieved by inserting the strips <NUM> and <NUM> as a pre-fabricated part into a mould for injection moulding the recess wall <NUM> and possibly more parts of the body of the mouthpiece. When the material for the recess wall is injected into the mould, this material may fuse with the foil or at least the back side <NUM> of the foil. In similar manner a single bristled strip for the recess wall bottom <NUM> may be provided and attached to the recess wall bottom <NUM>.

<FIG> shows two sets <NUM>, <NUM> of multiple bristle pads, which, in cross section transverse to <FIG>, may be in accordance with <FIG>. The sets <NUM>, <NUM> of bristled pads <NUM>, <NUM> are in this example in the form of three elongate bristled strips 70a, 70b, 7c and 71a, 71b, 71c. The first set <NUM> of bristled strips 70a, 70b, 70c is - as can be seen good in <FIG> - a little shorter than the second set of bristled strips 71a, 701b, 71c. <FIG> shows both sets of bristled strips in a flat condition and <FIG> shows both sets of bristled strips in a bended condition as they may have when attached in the body (not shown) of the mouthpiece. The longer set <NUM> is to be attached to the facial side - i.e. the outer side - of the recess and the shorter set <NUM> is to be attached to the lingual side - i.e. the inner side - of the recess. Referring to the embodiment of <FIG>, the bristled strips 70a, 70b, 70c and 71a, 71b, 71c are to be attached to the flexible recess wall <NUM>, strips 70a, 70b, 70c on one of the wall legs <NUM> and strips 71a, 71b, 71c on the opposing wall leg <NUM>. The strips 70a, 70b, 70c and 71a, 71b, 71c may be attached to the recess wall <NUM> by fusing the strips along their back surface <NUM> onto the recess wall <NUM>. This may for example be achieved by inserting the strips 70a, 70b, 70c and 71a, 71b, 71c as a pre-fabricated part into a mould for injection moulding the recess wall <NUM> and possibly more parts of the body of the mouthpiece. When the material for the recess wall is injected into the mould, this material may fuse with the foil or at least the back side <NUM> of the foil. In similar manner a set of multiple bristled pads for the recess wall bottom <NUM> may be provided and attached to the recess wall bottom <NUM>.

Referring to <FIG> it is noted that a single bristled strip <NUM> or 61according to <FIG> may be combined with a set <NUM> respectively <NUM> of bristled strips according to <FIG>. The same applies for the single bristled strip at the recess bottom <NUM> respectively the set of bristled strips for the recess bottom.

<FIG>, and <FIG> show different examples of manufacturing a bristled pad according to the invention. These examples have in common that a bristle holding tool <NUM> with perforations or bores is used, that a pre-fabricated foil <NUM> is provided, that prefabricated bristles <NUM> are provided, that the pre-fabricated bristles <NUM> are inserted into the perforations/bores of the tool, that the prefabricated bristles <NUM> and prefabricated foil are attached to each other by fusing the fixed ends <NUM> of the pre-fabricated bristles <NUM> with pre-fabricated foil <NUM>, and that after having the fixed ends of the bristles fused with the foil the tool <NUM> is removed. The difference between the examples is in the manner of heating the fixed ends of the bristles and or the foil for fusing them together.

Referring to <FIG> as heat stamp <NUM> is used. A heat stamp is a body heated electrically, heated by a fluid, or heated in any other manner for example by radiation. <FIG> shows an example of a starting configuration, in which the pre-fabricated bristled have been inserted into the perforations/bores of the bristle holding tool, in which the pre-fabricated foil is at a distance above the tool <NUM> and above the fixed ends <NUM> of the bristles, and in which the heat stamp may already be at its operating temperature. <FIG> shows a fusing configuration, in which the pre-fabricated foil <NUM> has been placed on top of the fixed ends of the bristles <NUM>, and in which the heat stamp <NUM> is pressed onto the back surface of the foil. The heat of the heat stamp causes the fixed ends <NUM> of the bristles to fuse with the foil, such as with the front surface of the foil. <FIG> shows the fabricated condition of the bristled pad, in which the bristle holding tool has been removed from the bristled pad.

Referring to <FIG>, it is also conceivable to use a perforated pre-fabricated foil, the perforations in the foil having the same pattern as the perforations/bores of the tool. In this case the foil <NUM> is placed onto the tool such that the fixed ends <NUM> of the bristles extend into the perforations of the foil and possibly project above the foil. The heat stamp <NUM> will then in the condition of <FIG> press directly onto the fixed ends <NUM> of the bristles <NUM>, causing these to melt and fuse with the foil.

Referring to <FIG>, a heating source <NUM> is - see <FIG> - placed between the pre-fabricated foil <NUM> and the fixed bristle ends <NUM> to heat the foil at its front surface <NUM> and to heat the fixed ends <NUM> of the bristles <NUM>. After having the foil and fixed ends of the bristles heated sufficiently, the heat source is removed and the heated foil is placed onto the heated ends of the bristles to allow them to fuse together, see <FIG>. This may be facilitated by a stamp, which may be heated, which exerts a pressure on the back surface of the foil. When the bristle ends are fused with the foil, the bristled pad obtained is removed from the tool (not shown in <FIG>). Like with the example of <FIG>, it is also conceivable to use a pre-fabricated, perforated foil in the example of <FIG>. The heating source <NUM> of <FIG> may be any type of heating source, like a heated body, an infra-red source, an electrical heating element, hot gas etcetera.

Referring to <FIG>, the pre-fabricated foil is placed between the fixed ends <NUM> of the bristles and a heating source <NUM>, which may be of similar type as the heating source <NUM> of <FIG>. In <FIG> the foil is shown at a distance above the fixed ends <NUM> of the bristles <NUM>, but in practice the pre-fabricated foil will be placed on top of the fixed ends when the back surface <NUM> of the foil is heated by the heat source <NUM>, which is as shown arranged at a distance from the foil <NUM> during the heating. The heating will cause the ends <NUM> of the bristles <NUM> to fuse with foil <NUM>. The fusing may be further facilitated by pressing, at the end of the heating process, a stamp against the back surface <NUM> of the foil. Like with the example of <FIG>, it is also conceivable to use a pre-fabricated, perforated foil in the example of <FIG>. The heating source <NUM> of <FIG> may be any type of heating source, like a heated body, an infra-red source, an electrical heating element, hot gas etcetera.

Referring to <FIG>, the fixed ends <NUM> of the bristles <NUM> project from the tool <NUM> and a heating source <NUM>, like the heating source of <FIG> or <FIG>, is used to melt the fixed ends <NUM>, see <FIG>. This results in the fixed ends <NUM> forming mushroom shaped heads <NUM>, see <FIG>. These mush room heads <NUM> prevent the bristles from slipping back into the bores of the tool when the foil <NUM> is placed on top of the ends <NUM>/mushroom heads <NUM>, see <FIG>. In order to establish the fusing, the foil is brought into contact with the mushroom heads and pressed downwards by means of a stamp not shown. This results in a bristled pad as shown in <FIG>, in the manufactured condition before removing the tool. The heating source <NUM> of <FIG> may be any type of heating source, like a heated body, an infra-red source, an electrical heating element, hot gas etcetera.

Referring to <FIG>, the foil is placed on top of the fixed ends <NUM> of the bristles supported in the bores of the tool <NUM>. The heating is done by means of laser, which may fuse each of the fixed ends one by one or group-wise with the foil. Like with the example of <FIG>, it is also conceivable to use a pre-fabricated, perforated foil in the example of <FIG>.

<FIG> shows an example of a bristled pad having a multilayer foil <NUM>. This multilayer foil may be a pre-fabricated multilayer foil. The foil <NUM> has a first outer layer <NUM> at the front surface side <NUM> of the foil and a second outer layer <NUM> at the back side of the foil. The first and second outer layer <NUM> and <NUM> may be of a different material. The first outer layer <NUM> may be of a second material identical to or similar to the first material from which the bristles are made. The second outer layer <NUM> may be of a fourth material identical to a third material of the bristle carrier of the body. The third material may be a material non-fusible with the first and/or second material, but may also be a material which is fusible with the first and/or second material. Similar the fourth material may be a material non-fusible with the first and/or second material, but may also be a material which is fusible with the first and/or second material. In case the first and second outer layer directly contact each other and the first and second outer layer are fusible with each other, the fusion may be much less strong than the fusion of the bristles with the first outer layer <NUM> but still strong enough due to the much larger contact surface between the two layers in relation to the cross-sections of the bristles. Referring to <FIG>, it is noted that the foil <NUM> of the resulting pad of <FIG> may very well be a multi-layered foil with a first outer layer <NUM> formed by the melt originating from the fixed ends of the fibers and a second outer layer <NUM> provided by the initial foil of <FIG>.

<FIG> shows a fourth example of manufacturing a bristled pad. This example is very similar to the example of <FIG>, the main difference being that in the example of <FIG> the prefabricated foil <NUM> is provided with perforations <NUM> which mate the pattern of bores <NUM> in the tool. A further difference is that <FIG> shows the fabrication with a multi layered prefabricated foil having a first outer layer <NUM> and a second outer layer <NUM>. However, it is to be noted that also a prefabricated, perforated single layer foil like in <FIG> can be used in the example of <FIG>. The other way around, in the examples of <FIG> also a prefabricated multilayer foil like the one of <FIG> may be used.

<FIG> shows as a first state, a tool <NUM> with bores <NUM>, a foil <NUM> having two outer layers <NUM> and <NUM> of - in this example - mutually different material and a heat stamp <NUM>. The heat stamp may be replaced by any other heat source <NUM>. The lower outer layer <NUM> may, in an embodiment, be of a material with which the bristles do not fuse or hardly do not fuse.

In the second state of <FIG>, the foil <NUM> is placed on the tool <NUM> with the perforations <NUM> aligned with the bores <NUM> and with tufts <NUM> inserted through the aligned bores <NUM> and perforations <NUM> such that the fixed ends <NUM> of the tufts <NUM> are about flush with the second outer layer <NUM> or project above the outer layer <NUM>.

In the third state of <FIG>, the heat stamp <NUM> is pressed on top of the fixed ends <NUM> of the tufts <NUM> end upper side of the second outer layer <NUM>, and the fixed ends <NUM> of the tufts are fused with the second outer layer <NUM>. Fusing the tufts with the second outer layer <NUM> instead of fusing them with the first outer layer <NUM> results in the first outer layer <NUM> serving as a retention layer preventing tufts from being pulled out. This because the fixed ends of the tufts will be widened a little due to the heat stamp <NUM> pressing on it.

<FIG> shows an end state in which the upper surface of the bristled foil is embossed. This embossment may be due to the fixed ends <NUM> of the tufts <NUM> projecting above the foil as shown in <FIG>. As shown in <FIG>, it is however also possible to obtain a bristled pad with an essentially flat surface of the second outer layer <NUM>.

Claim 1:
Method of manufacturing a bristled pad (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>) consisting of a pliable plastic foil (<NUM>; <NUM>) and plastic bristles (<NUM>; <NUM>; <NUM>; <NUM>) projecting from a front surface (<NUM>) of the foil (<NUM>; <NUM>), and the foil (<NUM>; <NUM>) having a back surface (<NUM>) opposite the front surface (<NUM>);
wherein the method comprises the following steps:
a) providing bristles (<NUM>; <NUM>; <NUM>; <NUM>) with a fixed end (<NUM>; <NUM>) and a free end (<NUM>);
b) providing a prefabricated foil (<NUM>; <NUM>) having a thickness of at most <NUM>, such as a thickness of at most <NUM> or at most <NUM> or at most <NUM>;
c) bringing the fixed ends (<NUM>; <NUM>) of the bristles (<NUM>; <NUM>; <NUM>; <NUM>) in contact with the foil (<NUM>; <NUM>);
d) heating the foil (<NUM>; <NUM>) and/or fixed ends (<NUM>; <NUM>) of the bristles (<NUM>; <NUM>; <NUM>; <NUM>);
e) fusing of the fixed ends (<NUM>; <NUM>) of the bristles (<NUM>; <NUM>; <NUM>; <NUM>) with the foil (<NUM>; <NUM>) resulting in the bristled pad (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>).