NL2021331B1

NL2021331B1 - Mouthpiece for brushing at a plurality of dental positions, brushing device comprising such mouthpiece, and method of operating such a mouthpiece or brushing device.

Info

Publication number: NL2021331B1
Application number: NL2021331A
Authority: NL
Inventors: Gideon Van Dijk Joppe
Original assignee: Dental Robotics Group B V
Priority date: 2018-07-17
Filing date: 2018-07-17
Publication date: 2020-01-24

Abstract

The invention relates to a mouthpiece for simultaneously brushing at a plurality of dental positions. The mouthpiece comprises a body with at least one recess. Said recess has a 5 curved length direction and a U-shaped cross-section transverse to the length direction and is configured for encompassing, viewed in the curved length direction, at least 5 dental positions. The body comprises a flexible recess wall delimiting the recess. The recess wall may be lined with a plurality of bristles extending from the recess wall into the recess. The body has at least one pressure chamber configured for containing a fluid under pressure. The body is configured to deform the recess wall by reciprocatingly increasing and decreasing a pressure in the pressure chamber between a decreased and increased pressure condition. The recess wall is configured to have such a local deformability that, when reciprocatingly increasing and decreasing the pressure in the at least one pressure chamber, the shape of the recess wall locally changes. In the increased pressure condition, the shape of the recess wall is locally adjusted to the local shape of the dental positions encompassed by the recess wall whilst, in the decreased pressure condition, the shape of the recess wall is locally less adjusted to the local shape of the dental positions encompassed by the recess wall than in the increased pressure condition.

Description

Title: Mouthpiece for brushing at a plurality of dental positions, brushing device comprising such mouthpiece, and method of operating such a mouthpiece or brushing device.

The invention relates to the field of dental cleaning devices, in particular to a mouthpiece for simultaneously brushing at a plurality of dental position. The invention further relates to a brushing device comprising the mouthpiece according to the invention. The invention furthermore relates to a method of operating such a mouthpiece or brushing device. The mouthpiece is configured to brush at at least 5 dental positions at the same time.

BACKGROUND OF THE INVENTION

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. Additionally, persons may exert too much pressure on brush bristles during brushing the teeth, whereby not only the bristles wear rapidly and excessively, but also the brushing process is not effective, teeth may be damaged, and tooth gum may withdraw which has adverse consequences for the dental health.

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 both the maxillary dental arch and the mandibular dental arch. Such a mouthpiece comprises brushing surfaces with bristles, which are automatically moved, to clean the complete set of teeth.

The mouthpiece and the brushing surfaces of the known dental cleaning devices require adjustment to fit closely to the shape of a user’s dental arch. The mouthpiece should be able to clean every tooth surface. However, dental arches vary greatly among different users due to varying sizes of the dental arch, malocclusion, missing teeth, and the like. So, there is a need for a dental cleaning device with an adjustable mouthpiece.

Reference US 2010/0062397 A1 discloses an electric dental cleaning device with a mouthpiece. This known mouthpiece has an upper part for cleaning the maxillary/upper arch of the teeth and a lower part for cleaning the mandibular/lower arch of the teeth. Both the upper part and the lower part of this know mouthpiece each have a brush pad, which brush pads each have a U-shaped cross section and bristles on the inside of the U-shape. These two brush pads are positioned with the bottoms of the U-shape of the pads facing towards each other and the legs of the U-shape of the upper brush pad pointing in an upward direction opposite to the legs of the U-shape of the lower brush pad, which point in downward direction. The brush-pads comprise rigid brush plates on the outside of the U-shape, a leg plate at each leg and a bottom plate transverse to the leg plates at the bottom of each Ushape. These U-shaped brush pads are driven up and down relative to the free ends/tops of the teeth in the direction of the legs of the U shape. In some embodiments, a bladder may be positioned between the maxillary arch and mandibular arch of the mouthpiece, i.e. between the bottom plates, and alternating or oscillating pneumatic pressure and suction may be applied to this bladder to move the bottom plates relative to each other, which in turn causes an up and down movement of the U-shaped brush pads, thereby brushing the teeth.

In one embodiment of the mouthpiece according to the reference US 2010/0062397 A1, the mouthpiece is adjustable in that the side/leg brush plates are positioned against the lingual and facial side of teeth by the use of flexible fingers and/or bladders which are configured to exert a static pressure to cause the tips of the bristles of the brush plates to engage the lingual and facial side of the teeth whilst moving up and down, transverse to the direction of the static pressure, along the lingual and facial side of the teeth in a direction.

In US 2010/0062397 A1 the brushing movement is only a 1-D-movement (one dimensional movement) as the U-shaped brush pads are only moved towards and away from each other.

The mouthpiece according to US 2010/0062397 A1 has a drawback of a limited brushing action, since the bristles on the brush pads have a limited capability to reach all surfaces of the teeth since they are mounted on rigid plates.

Reference US 4,795,347 - which has as corresponding European application, EP-A0173114 - discloses several embodiments of devices for cleaning a tooth, which can be divided in two types of devices each intended for encompassing one tooth at a time for, so to say, cleaning one tooth at a time. The device of the first type ensures a static brushing pressure of the bristles on the tooth whilst the brushing movement of the bristles is caused by hand, i.e. the brush head is mounted on a handgrip which is manipulated to move the brush head like a regular tooth brush along the tooth. In this first type one single pressure chamber or two opposing pressure bubbles may be used to ensure that the cleaning contact pressure between the individual bristle tufts and the tooth is at least approximately equal all over. Whilst in the first type the brushing movement of the tufts is to be caused by hand, the brushing movement of the device according to the second type is automated by a drive. The device of the second type, shown in figures 10-21 of US 4,795,347, is designed so that the tufts are driven to perform a 2-D-movement (two dimensional movement) with respect to the tooth surface. Each tuft is driven to move in a plane perpendicular to the dental arch, i.e. to the tooth cleaned. In a first stage the tufts are moved towards the tooth to press against the tooth, subsequently the tufts are moved along the tooth surface in a direction from the gum in tooth-axial direction towards the top/crown of the tooth, followed by moving the tufts away from the tooth to lower the pressure and moving the tufts back from the top/crown towards the gum of the tooth for starting the next cycle. In this second type pressure bubbles may be used to drive the tufts to perform this 2-D-movement. In these embodiments the tufts are mounted on a rigid cleaning element carriers onto which the pressure bubbles act directly or indirectly via rocker arms.

The automated mouthpiece according to US 4,795,347 A1 has as drawback a limited brushing action, since the tufts have a limited capability to reach all surfaces of the tooth since they are mounted on rigid carriers. A further disadvantage of this mouthpiece is that only one tooth at a time is cleaned in automated manner and that for cleaning all teeth the automated mouthpiece of US 4,795,347 has to be moved manually along all teeth, which is time consuming.

Thus there remains a need for an automatic dental cleaning device which is fast and thorough in cleaning multiple teeth simultaneously. Also, a need remains for an automatic dental cleaning device which requires as little effort from the user as possible. Also, a need remains for an automatic dental cleaning device which effectively reaches substantially all tooth surfaces.

Further reference is made to PCT/NL2018/050276 filed on 27 April 2018 by applicant. This application PCT/NL2018/050276 has not yet been published at the moment of filing the present application, i.e. this PCT/NL2018/050276 is not pre-published. The mouthpiece according to this earlier application of applicant is capable of brushing all teeth of the upper and lower dental arch in one go and has at least one pressure chamber comprising a flexible wall part provided with the bristles. The flexible wall part is configured to be deformable by alternatingly increasing pressure and decreasing pressure of a fluid in the pressure chamber.

SUMMARY OF THE INVENTION

It is an object of the invention to provide an alternative mouthpiece for brushing at a plurality of dental positions, in particular an automatic brushing device. A further object of the invention is to provide an improved mouthpiece for brushing at a plurality of dental positions and to provide a brushing device provided with the improved mouthpiece. Another further object is providing a mouthpiece for brushing at a plurality of dental positions and a brushing device comprising such a mouthpiece, which overcome one or more of the disadvantages of brushing mouthpieces respectively brushing devices known from the prior art. More specifically, the invention has as an object to provide a mouthpiece, like the one of the not pre-published PCT/NL2018/050276 from applicant or US 2010/0062397, with improved brushing action.

According to a first aspect of the invention, one or more of the above objects are achieved by providing a mouthpiece according to claim 1, having a preamble known from the not pre-published PCT/NL2018/050276.

According to the invention a mouthpiece is provided for simultaneously brushing at a plurality of dental positions. In other words a mouthpiece is provided which is configured for brushing at a plurality of dental positions at the same time. In case a natural or artificial tooth element is present at the dental position where the mouthpiece brushes, this tooth element is brushed. In case a tooth element is absent at the dental position where the mouthpiece brushes, the gum may be brushed.

The mouthpieces according to the invention comprises a body provided with at least one recess, which may be one or two recesses. This at least one recess has a curved length direction and a U-shaped cross-section transverse to the length direction and is configured for encompassing, viewed in the curved length direction, a plurality of at least 5 dental positions. The body comprises, per said recess, a flexible recess wall delimiting the respective recess. The recess wall may be a sheet, which may for example be made of a plastic, like polyethylene, polypropylene, polyester or nylon, or an elastomer, like a thermoplastic elastomer or a silicone elastomer. The recess wall may be lined with a plurality of bristles, each having one end attached to the recess wall and extending from the recess wall into the recess. In other words, the body has a recess, the wall of which may be covered with bristles distributed over the wall of the recess. At least five dental positions, like the tooth elements of these positions or the gum covering the jawbone at the location of the dental position, can be received in the recess, and, in case present, the bristles in the recess will be able to brush the at least 5 dental positions at the same time. The bristles may be of a nylon, an elastomer or any other suitable material. In case of a dental arch without teeth, the remaining arch of gum may need treatment as well. In this case the gum may be massaged by a recess wall without bristles. For improved cleaning of the gum, a cleaning fluid may be used in such a mouthpiece without bristles.

The body is according to the invention provided with at least one pressure chamber configured for containing a fluid under pressure, which pressure can be increased and decreased. The body is configured to deform the recess wall by reciprocatingly increasing and decreasing the pressure in the at least one pressure chamber causing a sustained repeating, reciprocating motion of the recess wall and bristles, optionally provided on that recess wall. The body thus comprises one, two, three, four, five, six or any other number of pressure chambers which can be filled with a fluid, as explained in PCT/NL2018/050276, which is in the name of the same applicant and not yet published at the day of filing the present application. By reciprocatingly increasing a pressure in the at least one of the pressure chambers from a decreased pressure condition to an increased pressure condition and decreasing the pressure in this pressure chamber(s) from the increased pressure condition to the decreased pressure condition and sustained repeating this reciprocating motion, the recess wall, optionally carrying bristles, is brought into motion resulting in the recess wall respectively the bristles acting at the dental positions on the objects - teeth and/or gum present at these dental positions - to clean said objects.

With respect to the terminology ‘increased pressure condition’ and ‘decreased pressure condition’ it is noted that these conditions are in relation to each other, i.e. in decreased pressure condition the pressure is lower than in increased pressure condition. In both conditions, the pressure may for example be lower than ambient air pressure.

Ambient air pressure is the pressure prevailing in the room where the user of the mouthpiece is when using the mouthpiece. In general ambient air pressure is assumed to be about 1 bar absolute pressure, but the actual value of the ambient air pressure will depend amongst others from the height with respect to sea level and weather conditions.

According to the invention the recess wall is configured to be locally deformable such that - or, in other words, to have such a local deformability that - when reciprocatingly increasing and decreasing the pressure in the pressure chambers or one or more one said at least one pressure chamber (‘in the pressure chambers or one or more said at least one pressure chamber’ will further be named ‘in a said at least one pressure chamber’), the shape of the recess wall locally changes, wherein, in the increased pressure condition, the bristles (or - in absence of bristles - the recess wall) are pressed against the dental positions and the shape of the recess wall is locally adjusted to the local shape of the dental positions encompassed by the recess wall whilst, in the decreased pressure condition, the shape of the recess wall is locally less adjusted to the local shape of the dental positions encompassed by the recess wall than in the increased pressure condition. So the recess wall may - thinking away the bristles - initially have a smooth surface, which, when increasing pressure, changes into a bumpy surface due to the locally deformable recess wall being pressed so to say against - again thinking away the bristles which are in between - the irregular contour of the dental positions. The recess wall thus is locally adjusted to the shape of the dental position(s) at that location. This adjusted shape in the increased pressure condition may be a mating adjustment, in which the shape of the recess wall is so to say identical to the contour of the dental positions, but this does not have to be the case and in practise may not be the case. When decreasing pressure, the recess wall will return in the direction of its initial state and assume a shape which is locally less adjusted - relative to the adjusted shape in the increased pressure condition -. This locally less adjusted shape may still be adjusted in some extent to the local shape of the dental contour, but the adjustment will be less pronounced. This change in shape of the recess wall between a locally adjusted shape and a locally less adjusted shape, results in that the bristles can better reach into interdental spaces, and results in an additional movement of the bristles on top of the movement already caused by increasing and decreasing the pressure in the at least one pressure chamber. This additional movement results in additional sweeping effect of the bristles. Summarizing the change in shape of the recess wall between a locally adjusted shape and a locally less adjusted shape results in improved brushing action.

According to a further embodiment of the first aspect of the invention, the recess wall may, viewed in the length direction along a lingual and facial side of the dental positions encompassed by the recess wall, have in the decreased pressure condition less relief than in the increased pressure condition.

According to a further embodiment of the first aspect of the invention, the local deformability of the recess wall may be configured such that the local changes in the shape of the recess wall, between the increased pressure and decreased pressure condition, occur at a pressure difference in a range up to 2 bar, such as in a range of up to 0.4 bar, the pressure difference being defined as the pressure in the pressure chamber in the increased pressure condition minus the pressure in the pressure chamber in the decreased pressure condition. With the expression ‘a pressure difference in a range up to x bar’, is meant a pressure difference as from zero (not including zero) up to x bar (including x bar). Keeping the pressure difference between the increased pressure condition and decreased pressure condition below 2 bar, prevents the user from experiencing an unbearable pressure difference. Keeping the pressure difference below 0.4 bar results in that the pressure difference between increased pressure condition and decreased pressure condition is, in general, experienced by a user as acceptable. The local deformability of the recess wall may be configured such that the local changes in the shape of the recess wall, between the increased pressure and decreased pressure condition, occur at a pressure difference in a range up to 0.2 bar, or even at lower pressure differences.

According to a further embodiment of the first aspect of the invention, the pressure in a said at least one pressure chamber may, in the decreased pressure condition, be higher than ambient air pressure.

According to a further embodiment of the first aspect of the invention, the pressure in a said at least one pressure chamber may, in the increased pressure condition, be at most 2 bar relative to ambient air pressure, such as at most 1 bar relative to ambient air pressure.

According to a further embodiment of the first aspect of the invention, the pressure in a said at least one pressure chamber may, in the increased pressure condition, be at most 0.3 bar relative to ambient air pressure, such as at most 0.2 bar relative to ambient air pressure. With a pressure of at most 0.3 bar the brushing action is satisfactory, whilst the risk of harm or injury in case the recess might rupture is minimal. With a pressure of at most 0.2 bar the brushing action is still satisfactory.

According to a further embodiment of the first aspect of the invention, the mouthpiece according to one of the preceding claims, the pressure in a said at least one pressure chamber is, in the decreased pressure condition, lower than ambient air pressure.

According to a further embodiment of the first aspect of the invention, the pressure in a said at least one pressure chamber may, in the decreased pressure condition, be in the range of -0.5 to +0.2 bar relative to ambient air pressure, such as in the range of -0.5 to 0 bar relative to ambient air pressure. With a decreased pressure of at least -0.5 bar the chance that the recess wall might become damaged is low. The decreased pressure may be in the range of -0.4 to -0.25 relative to ambient air pressure. A decreased pressure in the range of -0.4 to -0.25 bar relative to ambient air pressure can be realized with relatively cheap means. A decreased pressure with a value below zero relative to ambient air pressure, means that, when decreasing pressure to the decreased pressure condition, a vacuum is created in the pressure chamber. Using a pressure below ambient air pressure for the decreased pressure condition means that the chances to damage the gum of the user are reduced considerably.

According to a second aspect of the invention, which may be separate from or in combination with one/or more other aspects of the invention, the invention provides a mouthpiece for simultaneously brushing at a plurality of dental positions, like as worded in independent claim 9. To define this second aspect, a system of three mutually orthogonal axes is defined, comprising an x-axis, an y-axis, and a z-axis, the z-axis being a curved axis following the contour of a dental arch - for example the dental arch of an adult human -, the x-axis and y-axis being perpendicular to each other and defining an xy-plane which is flat and perpendicular to the curved z-axis. The mouthpiece of this second aspect comprises a body provided with at least one recess. As is also the case with the other aspects of this invention, in use this mouthpiece will be inserted in the mouth of the user. So the dimensions of the mouthpiece may be configured to allow insertion into the mouth of a user. The at least one recess has a curved length direction extending parallel to the z-axis, an U-shaped crosssection transverse to the length direction, and is configured for encompassing, viewed in the curved length direction, a plurality of at least 5 dental positions. The body comprises, per said recess, a recess wall delimiting the respective recess and provided with a plurality bristles. As also may be the case in the other aspects of this invention, the bristles may be flexible and/or deformable. Each bristle has a fixed end which is, at the recess wall, attached to the body. The fixed ends of the bristles may for example be attached to the recess wall, but may also be attached to another part of the body. Each bristle extends from the fixed end, into the recess, towards the free end of the bristle, which free end is arranged in the recess. The body is according to this second aspect configured to subject, when a said plurality of dental positions is encompassed in the recess, a multiple of said free ends of the bristles - for example each free end of each bristle - reciprocatingly to a first back and forth pivot movement around a first pivot axis, a second back and forth pivot movement around a second pivot axis and a back and forth translation movement along a translation axis, the first pivot axis, the second pivot axis and the translation axis being mutually perpendicular, the first pivot axis being parallel to the z-axis, and the second pivot axis and translation axis extending in the xy-plane. Configuring the body to subject fixed ends of the bristles to these movements, may be accomplished with - see also the next paragraph - a said body comprising a pressure chamber and a recess wall which is locally deformable and carries the fixed ends of the bristles, but may also be accomplished with a different mounting of the fixed ends of the bristles and/or a different drive to subject the fixed ends of the bristles to these movements.

According to a further embodiment of the first and/or second aspect of the invention, the local deformability of the recess wall may be such that, when reciprocatingly increasing and decreasing the pressure in a said at least one pressure chamber and encompassing said plurality of dental positions in the recess, each location of the recess wall is subjected to a first back and forth pivot movement around a first pivot axis, a second back and forth pivot movement around a second pivot axis and a back and forth translation movement along a translation axis, the first pivot axis, the second pivot axis and the translation axis being mutually perpendicular.

According to a further embodiment of the first and/or second aspect of the invention, each bristle is at a root of the respective bristle be attached to the recess wall, and the local deformability of the recess wall may be such that, when reciprocatingly increasing and decreasing the pressure in a said at least one pressure chamber and encompassing said plurality of dental positions in the recess, the root of each bristle is subjected to a first back and forth pivot movement around a first pivot axis, a second back and forth pivot movement around a second pivot axis and a third back and forth translation movement along a translation axis, the first pivot axis, the second pivot axis and the translation axis being mutually perpendicular.

According to a further embodiment of the first and/or second aspect of the invention, each respective bristle may be attached to the recess wall in an attachment point; at each attachment point, a local set of three mutually orthogonal axes may be defined, which local set comprises an x-axis, an y-axis and a z-axis, the z-axis being a curved axis defined by the curved length direction of the recess, the x-axis and y-axis defining an xy-plane perpendicular to the z-axis; and the local deformability of the recess wall may be such that, when reciprocatingly increasing and decreasing the pressure in a said at least one pressure chamber and encompassing a said plurality of dental positions in the recess, the attachment points are subjected to one or more movements from the group of: a first back and forth pivoting movement around a first pivot axis, a second back and forth pivoting movement around a second pivot axis, and a back and forth translating movement along a translation axis; wherein the first pivot axis is parallel to the z-axis and the second pivot axis and translation axis are in the xy-plane and mutually perpendicular. In addition to these first, second and third back and forth movement, it is noted that the recess wall may also allow a fourth, fifth and sixth back and forth movement which may further contribute to the brushing action, wherein, viewed at the location of the root of the bristle, the fourth back and forth movement is a back and forth translation movement in the direction of the z-axis, the fifth back and forth movement is a back and forth translation movement in the direction of the yaxis, and the sixth back and forth movement is a back and forth rotation movement around the x-axis.

According to a further embodiment of the first and/or second aspect of the invention, the body may be provided with two said recesses, the openings of the U-shaped crosssections of the two recesses facing in mutually opposite directions. This allows upper dental positions and lower dental positions to be brushed at the same time.

According to a further embodiment of the first and/or second aspect of the invention, wherein the recess wall is, transverse to the length direction, U-shaped in conformity with the U-shaped cross-section of the recess; wherein the U-shape of each recess wall defines two recess wall legs extending from a recess wall bottom, each leg having a free end; wherein the free ends of the legs are provided with end bristles; and wherein the body is configured

- to shift the upper ends of the legs from inside the recess to outside the recess when increasing the pressure in said at least one pressure chamber, and

- to decrease the vertical distance and to shift the upper ends of the legs from outside the recess to inside the recess when decreasing the pressure in said at least one pressure chamber such that the end bristles are subjected to a back and forth swivelling movement around an axis parallel to the length direction when reciprocatingly increasing and decreasing the pressure in a said at least one pressure chamber. A ‘roller bellow functionality’ is introduced. The reciprocating shifting of the ends of the legs from inside the recess to outside the recess causes the end bristles into a back and forth swivelling movement around an axis parallel to the curved length direction. As a result the transitions of the teeth to the gums are subjected to a special brushing action of these end bristles. As is generally known, these transitions need careful cleaning care. According to a third aspect of the invention, this ‘roller bellows functionality’ may also be applied separate from the first and/or second aspect of the invention, as may be worded, like in independent claim 15 (which has been delimitated against the not pre-published PCT/NL2018/050276), as follows: “A mouthpiece for simultaneously brushing at a plurality of dental positions; wherein the mouthpiece comprises a body provided with at least one recess; wherein the said at least one recess has a curved length direction and a U-shaped cross-section transverse to the length direction and is configured for encompassing, viewed in the curved length direction, a plurality of at least 5 dental positions; wherein the body comprises, per recess, a flexible recess wall delimiting the respective recess; wherein the recess wall is lined with a plurality of bristles, each having one end attached to the recess wall and extending from the recess wall into the recess; wherein the body is provided with at least one pressure chamber configured for containing a fluid under pressure; wherein the body is configured to deform the recess wall by reciprocatingly increasing and decreasing a pressure in the at least one pressure chamber between a decreased pressure condition and an increased pressure condition; wherein the recess wall is, transverse to the length direction, U-shaped in conformity with the U-shaped cross-section of the recess; wherein the U-shape of each recess wall defines two recess wall legs extending from a recess wall bottom, each leg having a free end; and wherein the body is configured:

- to shift the upper ends of the legs from inside the recess to outside the recess when increasing a pressure in said at least one pressure chamber, and

- to shift the upper ends of the legs from outside the recess to inside the recess when decreasing the pressure in said at least one pressure chamber such that the end bristles are subjected to a back and forth swivelling movement around an axis parallel to the length direction when reciprocatingly increasing and decreasing the pressure in a said at least one pressure chamber’.

According to a further embodiment of the first and/or second and/or third aspect of the invention, the body may be configured to subject the legs of the recess walls to a reciprocating movement in the vertical direction when reciprocatingly increasing and decreasing pressure in a said at least one at least one pressure chamber.

According to a further embodiment of the first and/or second and/or third aspect of the invention, the body may be configured to elongate the legs when increasing the pressure in the at least one pressure chamber and to shorten the legs when decreasing the pressure in the at least one pressure chamber. Elongating and shortening of the legs causes the bristles on the legs to move with respect to the dental positions in a length direction of the legs.

According to a further embodiment of the first and/or second and/or third aspect of the invention, the body defines a reference plane parallel to the curved length direction, the free ends of the legs pointing away from the reference plane and an outer side of the bottom facing the reference plane; wherein a vertical distance is defined as a distance, measured in a direction transverse to the reference plane, from the reference plane to the free ends of the legs; and wherein the body is further configured:

to increase the vertical distance when increasing a pressure in said at least one pressure chamber, and to decrease the vertical distance when decreasing the pressure in said at least one pressure chamber.

Increasing and decreasing the vertical distance causes the bristles on the legs to move with respect to the dental positions in the direction of the vertical distance.

According to a further embodiment of the first and/or second and/or third aspect of the invention, the mouthpiece may further comprise a meshwork fixed to the recess wall, wherein the meshwork is formed by nodes and mesh members, each said mesh member extending from one said node to another said node, each said node connecting at least three said mesh members to each other, and wherein each node carries one or more of said bristles or a tuft of said bristles. This ‘mesh functionality’ simplifies production of a mouthpiece according to the invention. The mesh with bristles on the nodes can be produced as a separate component, separate from and preceding the manufacturing of the mouthpiece. During or after manufacturing of the mouthpiece, the mesh with bristles can be arranged to lie over the recess wall. According to a fourth aspect of the invention, this ‘mesh functionality’ may also be applied separate from the first aspect and/or second and/or third aspect of the invention, as may be worded, like in independent claim 19 (which has been delimitated against the not pre-published PCT/NL2018/050276), as follows: “A mouthpiece for simultaneously brushing at a plurality of dental positions; wherein the mouthpiece comprises a body provided with at least one recess; wherein the at least one recess has a curved length direction and a U-shaped cross-section transverse to the length direction and is configured for encompassing, viewed in the curved length direction, a plurality of at least 5 dental positions; wherein the body comprises, per said recess, a recess wall delimiting the respective recess; wherein the recess wall is lined with a plurality of bristles extending from the recess wall into the recess; wherein the body may optionally be provided with at least one pressure chamber configured for containing a fluid under pressure, the body optionally being configured to deform the recess wall by reciprocatingly increasing the pressure in the at least one pressure chamber from a decreased pressure condition to an increased pressure condition and decreasing pressure in the at least one pressure chamber from an increased pressure condition to a decreased pressure condition; wherein the mouthpiece further comprises a meshwork lying against the recess wall or fixed to the recess wall; and wherein the meshwork is formed by nodes and mesh members, each said mesh member extending from one said node to another said node, each said node connecting at least three said mesh members to each other, and wherein each node carries one or more of said bristles ora tuft of said bristles. ”

According to a further embodiment of the first and/or second and/or third and/or fourth aspect of the invention, the meshwork may lie in a cut away of the recess wall, or may embedded in material of the recess wall, or may be adhered or glued to the recess wall, or may be positioned in the pressure chamber and overlapping holes in the recess wall through which the tuft of bristles extend externally from the recess wall.

According to a further embodiment of the first and/or second and/or third and/or fourth aspect of the invention, wherein each respective mesh member has a length direction defined by an imaginary straight line extending between two said nodes, between which nodes the respective mesh member extends, the mesh members may be stretchable in their length direction or at least a part of the mesh members is stretchable in their length direction. The mesh-members being stretchable allows the mesh to follow deformations of the recess wall, like stretching or like local changes in shape of recess wall during increasing and decreasing pressure. The stretchable mesh members may be elastically stretchable and/or may have, viewed in the length direction of the respective mesh member, a zig-zag structure configured for providing said stretchability.

According to a further embodiment of the first and/or second and/or third and/or fourth aspect of the invention, the mesh members or at least part of the mesh members may be configured to break when a predetermined force (like a stretching force) acting on the respective mesh members, is exceeded. The mesh-members being breakable allows the mesh to follow deformations of the recess wall, like stretching or like local changes in shape of recess wall during increasing and decreasing pressure. Additionally, the mesh-members being breakable allows the nodes of the mesh being attached to the recess wall, whilst the mesh is still one unit, during manufacturing of the mouthpiece and subsequently breaking these mesh-members, for example by excessively increasing pressure in the pressure chambers during or at the end of the production of the mouthpiece in order to allow, at use, the nodes to move independently from each other together with movement of the recess wall due to increasing and decreasing pressure.

According to a further embodiment of the first and/or second and/or third and/or fourth aspect of the invention, the at least one recess may be configured for encompassing, viewed in its curved length direction:

- the dental positions in the range from a central incisor up to a first molar; and/or

- the dental positions in the range from a central incisor up to a second molar; and/or

- the dental positions in the range from a right second premolar up to a left second premolar; and/or

- the dental positions in the range from a right first molar up to a left first molar; and/or

- the dental positions in the range from a right second molar up to a left second molar.

The curved length direction of the recess defining a curved length axis, this means that the length of the length axis of the recess (or recess wall) spans a distance:

- at least equal to the distance from a central incisor up to a first molar; and/or

- at least equal to the distance from a central incisor up to a second molar; and/or

- at least equal to the distance from a right second premolar up to a left second premolar; and/or

- at least equal to the distance from a right first molar up to a left first molar; and/or

- at least equal to the distance from a right second molar up to a left second molar. Further in addition, the curved length axis may have a shape similar to the shape of a human dental arch or similar to at least part of the shape of a human dental arch.

According to a further embodiment of the first and/or second and/or third and/or fourth aspect of the invention, the bristles may, at their ends attached to the recess wall, be fixed relative to the recess wall.

According to a further embodiment of the first and/or second and/or third and/or fourth aspect of the invention, the recess wall may be lined with at least 5 bristles per cm². The recess wall may for example be lined with 40 to 200 bristles per cm² in case of for example elastomeric bristles or with 1000 to 6000 bristles per cm² in case of for example bristles of nylon.

According to a further embodiment of the first and/or second and/or third and/or fourth aspect of the invention, wherein the recess wall is, transverse to the length direction, Ushaped in conformity with the U-shaped cross-section of the respective recess, and wherein a central axis is defined as the mirror axis of the U-shape and the U-shape of the recess defines two legs extending in the direction of the central axis, the legs may be provided or lined with bristles extending at an angle in the range of 0 to 90 degrees, such as in the range of 30 to 60 degrees, with respect to the central axis. When the bristles extend at such an angle, they point so to say, in a neutral position, towards the gum. When increasing pressure the pressure chamber, the recess wall will be pressed towards the dental positions resulting in the bristles tips being be pushed towards the gum, which in turn contributes to the brushing action. For example, the free ends of the legs may be provided with bristles extending at an angle in the range of 45 to 90 degrees, such as in the range of 40 to 70 degrees, with respect to the central axis.

According to a further embodiment of the first and/or second and/or third and/or fourth aspect of the invention, the recess wall may be elastically deformable.

BRIEF DESCRIPTION OF THE DRAWINGS

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

Figure 1 shows a lower dental arch with dental positions and a system of three orthogonal axes defining a dental arch.

Figure 2 shows a perspective view of a mouthpiece according to a first embodiment of the first aspect of the invention.

Figures 3a, 3b and 3c schematically show cross-sectional views of a part of second embodiment of a mouthpiece according to the first aspect of the invention, in different respective operational states thereof, the cross sectional views corresponding with the cross section as indicated with arrows ll-ll in figure 2.

Figure 4 schematically shows a top view of a third embodiment of the mouthpiece according to the first aspect of the invention.

Figures 5a, 5b, 5c schematically show cross-sectional views of a part of the third embodiment of a mouthpiece according to the first aspect of the invention, in different respective operational states thereof, the cross sectional views corresponding with the cross section as indicated with arrows IV-IV in figure 4.

Figures 6a, 6b, 6c, 6d give an elucidation of the second aspect of the invention and of the local deformability of the recess wall of a mouthpiece according to the first aspect of the invention.

Figures 7a and 7b give an elucidation a recess wall which is not locally deformable.

Figures 8a and 8b give a further elucidation of the local deformability of the recess wall of a mouthpiece according to the first aspect of the invention.

Figure 9 gives another further elucidation of the local deformability of the recess wall of a mouthpiece according to the first aspect of the invention.

Figures 10a, 10b, 10c schematically show cross-sectional views of a part of a first embodiment of a mouthpiece according to the third aspect of the invention, in different respective operational states thereof.

Figures 11a, 11b, 11c schematically show cross-sectional views of a part of a second embodiment of a mouthpiece according to the third aspect of the invention, in different respective operational states thereof.

Figure 12 shows schematically a mesh structure according to a first embodiment of the third aspect of the invention.

Figures 13a and 13b show schematically a mesh structure according to a second embodiment of the fourth aspect of the invention.

Figures 14a and 14b show schematically a mesh structure according to a third embodiment of the fourth aspect of the invention.

Figures 15a and 15b show schematically a mesh structure according to a fourth embodiment of the fourth aspect of the invention.

Figures 16a and 16b show schematically a mesh structure according to a fifth embodiment of the fourth aspect of the invention.

Figures 17a and 17b show schematically a mesh structure according to a sixth embodiment of the fourth aspect of the invention.

Figure 18 shows schematically a detail with a flexible recess wall.

Figure 19 shows schematically a dental cleaning device according to the invention comprising a mouthpiece according to the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

Figure 1 shows in perspective view, highly schematically a part of an upper dental arch 1 with dental positions 2-14. 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:

- dental position 2 is the position of the left ‘second molar’, present in figure 1;

- dental position 3 is the position of the left ‘first molar’, missing in figure 1;

- dental position 4 is the position of the left ‘second premolar’, present in figure 1;

- dental position 5 is the position of the left ‘first premolar’, present in figure 1;

- dental position 6 is the position of the left ‘canine’, present in figure 1;

- dental position 7 is the position of the left ‘lateral incisor’, missing in figure 1;

- dental position 8 is the position of the left ‘central incisor’, present in figure 1;

- dental position 9 is the position of the right ‘central incisor’, present in figure 1;

- dental position 10 is the position of the right lateral incisor’, present in figure 1;

- dental position 11 is the position of the right ‘canine’, present in figure 1;

- dental position 12 is the position of the right ‘first premolar’, present in figure 1;

- dental position 13 is the position of the right ‘second premolar’, present in figure 1;

- dental position 14 is the position of the right ‘first molar’, present in figure 1;

In figure 1 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 15 indicates the lingual side of the arch of dental position. The lingual side 15 is the inner side of the arch of dental positions, which inner side faces the tongue. Reference number 16 indicates the facial side of the arch of dental positions. The facial side 16 is the outer side of the arch of dental positions, which outer side faces the face, like the cheeks and lips.

The mouthpiece according to the invention 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. Due to the local deformability of the recess wall according to the invention, the remnants at a dental position, like the gum, will be brushed in case a tooth may be missing and the teeth adjacent the location of the missing tooth will be additionally brushed by bristles intended for the location of the missing tooth.

Figure 1 further shows a system of three mutually orthogonal axes, comprising an xaxis 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 1. The x-axis x and y-axis y are perpendicular to each other and define an xyplane which is essentially flat and perpendicular to the dental arch 1, 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 zyplane, with viewed along the z-axis, an arch shape similar to the shape of the arch of dental positions. Further, the z-axis Z and X-axis X define a zx-plane.

Figure 2 shows schematically a perspective view of a mouthpiece 20 according to the invention. The mouthpiece 20 comprises a body 21 provided with a first recess 22. This first recess 22 has, viewed along the z-axis of figure 1, a curved length direction and, viewed in the xy-plane of figure 1, an U-shaped cross section. The first recess 22 is delimited by a recess wall 23, which is in the xy-plane U-shaped. The recess wall 23 is lined with a plurality of bristles 24, each having one end, called the root 49, attached to the recess wall 23 and extending from the recess wall 23 into the first recess 22.

Reference 26 indicates a nipple configured for connecting the mouthpiece to a pumping and/or suctioning device. The mouthpiece 20 further has a right half 27 and a left half 28, which halves come so to say together at nipple 26.

Reference 25 indicates a curved dividing line, which defines a mirror plane parallel to the xz-plane as defined in figure 1. The mouthpiece as shown in figure 2 is so to say mirror symmetrical with respect to this mirror plane, meaning that there is a second recess (not visible in figure 2) opposite the first recess 22, which second recess is lined with bristles as well. This second recess is however visible in amongst others figure 3, where it has been indicated with reference number 22 as well. It is noted that the first recess may have a shape different than the shape of the second recess because the (teeth of the) upper and lower arch of dental positions have different shapes.

The recesses 22 are configured to encompass an entire dental arch from the dental position of the right third or second molar to the dental position of the left third respectively second molar. The recesses 22 may also be configured to encompass a part of an arch of dental positions, this part comprising at least five dental positions, for example from the dental position of a central incisor to the dental position of a second premolar or to the dental position of a first molar or a dental position of a second molar.

Figure 3 shows cross-sections according to arrows II in figure 2 of a right part of a second embodiment of the mouthpiece 100 according to the invention in different pressure conditions. In figure 3 same reference numbers have been used as in figure 2 for similar parts.

The mouthpiece of figure 2 and the mouthpiece of figure 3 may be essentially the same, figure 2 showing a perspective view and figure 3 showing a cross section ll-ll of part of the mouthpiece of figure 2. The main difference then is in the bristles. In figure 2 the bristles 24 are relatively thick and may be made as one integral part with the recess wall 23, whilst in figure 3 the bristles are provided as tufts 29 of relatively thin bristles 24. Each tuft 29 may have a base 36 which carries the bristles 24 at their roots 49 and is attached to the recess wall.

As shown in figure 3, the mouthpiece 100 has a body 21 having in its upper side a first recess 22 and in its lower side a second recess 22. Both recesses 22 are delimitated by a flexible recess wall 23. In cross-section parallel to the xy-plane as defined in figure 1, the recess walls 23 are U-shaped and have a recess wall bottom 34 and two recess wall legs 33 extending from the recess bottom wall. The recess wall 23 is covered with tufts 29 of bristles.

Inside the body there is provided a pressure chamber 35, which may, via the nipple 26 (figure 2), be filled with a fluid. The fluid may be a gas, like air, or a liquid, like water. In the embodiment as shown in figure 3, the mouthpiece has one pressure chamber. It is however noted that the mouthpiece may comprise a plurality of pressure chambers, like 5 pressure chambers as shown in figures 4 and 5, or any other number of pressure chambers. The not pre-published PCT/NL2018/050276 shows examples of other numbers of pressure chambers in figures 4, 5, 7, 9 and 10, which are all within the scope of the present invention. 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 the not pre-published PCT/NL2018/050276.

As shown in figure 3, the mouthpiece may comprise an internal support structure of a material which is rigid relative to the material of the recess wall 23. This support structure may structure comprise a lingual plate 30 and a facial plate 32, both extending along, for example parallel to, the curved zy-plane defined in figure 1 and consequently, viewed along the z-axis, having a U-shape. In order to keep the lingual plate 30 and facial plate 32 at a distance from each other, the support structure may comprise one or more spacers 31. These one or more spacers 31 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 figure 1. In case of a single plate as spacer, this plate may divide the pressure chamber 35 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.

Figures 3a, 3b and 3c schematically depict cross-sectional views of the mouthpiece 100, in different respective operational states thereof. This cross-sectional view might be about the same all over the length axis Z - as defined in figure 1 - of the dental arch.

The single pressure chamber 35 comprises a first flexible recess wall 23 delimiting the first recess 22 (the upper one in figure 3) and a second flexible recess wall 23 delimiting the second recess 22 (the lower one of figure 3). The first and second recess walls are deformable, in particular by increasing or decreasing the pressure in the pressure chamber 23. The flexible recess walls 23 may be made from an elastic material, such as a rubberlike material. The flexible recess walls 23 may also be made from a non-elastic material. The material of the flexible recess walls 23 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 23.

The mouthpiece 100 is configured for the tufts 29 of bristles 24 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 35 is increased. In case a tooth might be missing at a dental position, especially the tufts 29 of bristles at the free ends of the recess wall legs 33 will engage the gum at the empty dental position.

Viewed in length direction Z of the dental arch - as defined in figure 1 -, the tufts 29 of bristles 24 may be arranged at about the same density as viewed in the cross-sections shown in figures 3a, 3b, 3c.

Figure 3a illustrates a first operational state, also called intermediate state, of the mouthpiece 100. The pressure in the pressure chamber 35 may in the intermediate state be equal to ambient air pressure, lower than ambient air pressure or higher than ambient air pressure.

Figure 3b illustrates a second operational state of the mouthpiece 100 when the pressure chamber 35 is in increased pressure condition, for example by feeding a fluid to the pressure chamber 35, or increasing an amount of fluid in the pressure chamber 35. As can be seen in Figure 3b, as a result of increasing pressure, the recess walls 23 are so to say compacted to narrow the recess 22 (with respect to figure 3a), whereby the bristles 24, in particular the free ends thereof, may engage tooth surfaces firmly and/or may be deformed against tooth surfaces.

Figure 3c illustrates a third operational state of the mouthpiece 100 when the pressure in the pressure chamber 35 is decreased, for example by discharging a fluid from the pressure chamber 35, or decreasing an amount of fluid in the pressure chamber 35. As can be seen in Figure 3c, as a result of decreasing pressure, the flexible recess walls 23 are, compared with figure 3a, so to say dilated to enlarge the recess 22, whereby the bristles 24, in particular the free ends thereof, less firmly engage tooth surfaces (or do not engage tooth surface at all) and/or become less deformed against the tooth surfaces.

By a suitable cycle of increasing and decreasing pressure in the pressure chamber 35 to go from the first operational state to the second operational state, then from the second operational state to the first operational state, then from the first operational state to the third operational state, followed by a return to the first operational state, and subsequently repeating such cycle, a most effective brushing action of the mouthpiece can be obtained. The bristles 24 attached to the recess wall bottom 34 generally perform an upward and downward motion during such cycling, and the bristles 24 at the recess wall legs 33 generally perform a sideways motion to and fro during such cycling in the direction of the x-axis as defined in figure 1. Due to the recess 22 alternatively narrowing and widening when reciprocatingly increasing and decreasing pressure, the bristles 24 at the recess wall legs will also be subjected to a back and forth pivoting around the z-axis as defined in figure 1, resulting in a sweeping movement of the bristles in the direction of the y-axis as defined in figure 1.

It is noted that, in the operational state of figure 3c (decreased pressure condition), the pressure in the pressure chamber 35 may be a vacuum, i.e. a pressure lower than ambient air pressure. When in the operational state of figure 3c (increased pressure condition) the pressure in the vacuum chamber is a vacuum, for example 0.7 bar, the pressure in the pressure chamber 35 may, in the operational state of figure 3b, be either a vacuum, ambient air pressure or a pressure higher than ambient air pressure. Additionally, it is noted that it is also possible that in the operational states of figures 3b as well as 3c the pressure in the pressure chamber may be both higher than ambient air pressure or that in the operational state of figure 3b the pressure in the pressure chamber is about ambient air pressure whilst in the operational state of figure 3c the pressure in the pressure chamber is higher than ambient air pressure.

Just by way of example to give some indication of dimensions and referring to figure

1, for an adult human the width of a teeth element in the X direction varies, depending on the dental position between about 2 to 12 mm. Taking into account that it is desired to keep the mouthpiece as small as possible, the internal width of the U-shape of the recess wall in the X direction is to be kept as small as possible and may be about 0 to 4 mm wider than the width of the respective tooth. By way of example to give some indication of dimensions, the internal width of the U-shape of the recess wall, viewed in the X-direction of figure 1, may be in the range of 0 to 20 mm, such as in the range of 2-12 mm. The bristles may be up to 6 mm long. In case for example the bristles are 3 to 4 mm long, this means that between the bristles extending from opposing recess wall legs 33 no interspace or a limited amount of interspace of about 2-4 mm is left. In figure 3, these interspaces are shown exaggerated. Further by way of example to give some indication of dimensions, the U-shape of the recess wall may have, viewed in the Y-direction of figure 1, an internal height in the range of 3 to 20 mm, such as in the range of 5 to 10 mm. These internal width and internal height measures are indicative for an adult human. For a child or for animals these measures might be different.

Figure 4 schematically depicts a top view of a third embodiment 110 of a mouthpiece according to the invention. Figures 5a, 5b and 5c schematically depict cross-sectional views, according to the arrows IV-IV in figure 4, of the mouthpiece 110, in different respective operational states thereof. This cross-sectional view might be about the same all over the length axis Z - as defined in figure 1 - of the dental arch.

Taking into account that the mouthpiece 110 of figures 4-5, is very similar to the mouth piece 110 of figure 3, the same reference numbers have been used for same or similar parts of the mouthpiece 110 as have been used in relation to figures 2-3.

There are essentially two differences between the mouthpiece 100 of figure 3 and the mouthpiece 110 of figures 4-5. Each one of these differences may be applied separately to the mouthpiece of figure 2 and/or figure 3 without applying the other difference.

The first difference is that the mouthpiece of figures 4-5 has five pressure chambers 35a, 35b, 35c, 35d and 35e. In figure 4 the pressure chambers 35a, 35c and 35e have been made visible by means of shaded grey areas. As can also be seen in figure 4, the nipple 26 has a channel 37a for providing a fluid communication with an external pressure source. This channel 37a debouches in pressure chambers 35c and 35a (not shown in figure 4). The channel 37b connects the pressure chambers 35c and 35a with the pressure chamber 35e and provides a fluid communication between these chambers. The channel 37c connects the pressure chamber 35e with the pressure chambers 35a and 35b and provides a fluid communication between these chambers. Overall, all pressure chambers 35a, 35b, 35c, 35d and 35e are in fluid communication with each other so that they may act as one single pressure chamber, like the pressure chamber 35 of mouthpiece 100. Similar like described in relation to figures 3a, 3b, and 3c also the mouthpiece 110 may have 3 operational states or two operational states in case one might be left out. For description of the operational states shown in figures 5a, 5b and 5c reference is made to the description of figures 3a, 3b and 3c.

The second difference is that the mouthpiece of figures 4-5 has a slightly different support structure. The lingual plate 30 and facial plate 32 of the mouthpiece 110 are arranged on the outside of the body 21 instead of embedded inside the body as is the case in the mouthpiece 100. Also the lingual plate 30 and a facial plate 32 of mouthpiece 110 both extend along the curved zy-plane defined in figure 1 and consequently, viewed along the zaxis, have a U-shape. In the embodiment of figures 4 and 5, the lingual plate 30 and facial plate 32 may be kept at a distance from each other by additional spacers, not shown, but also the recess wall bottoms 34 may serve as such a spacer.

Referring to figures 6-9, the local deformability of the recess wall according to the first aspect of the invention will now be explained and also the second aspect of the invention will be explained.

Up to here, with reference to figures 1-5, a global deformability of the recess wall 23 has been described, which global deformability occurs upon the actuation of the at least one pressure chamber 35 with bristles 24 or tufts 29 with bristles 24 attached on the recess wall 23. However, according to the first aspect of the invention, the recess wall 23 is further configured to have a local deformability. This local deformability of the recess wall 23 will now be elucidated with reference to figures 6a, 6b, 6c and 6d.

Figures 6a and 6b are basically identical. The difference is that in figure 6b only one tuft 29 is shown for illustrative purpose, whilst in figure 6a a plurality of tufts 29 is shown.

Figures 6a and 6b show schematically a dental arch 1 and a flexible recess wall leg 33 of the flexible recess wall 23 on the facial side of the dental arch 1. This flexible recess wall leg 33 is locally deformable.

As these figures 6a and 6b are for purpose of elucidation, the rest of the recess wall leg 33 extending along the facial side of the dental arch 1, the recess wall leg 33 extending along the lingual side of the dental arch 1 and the recess wall bottom 34 extending along the occlusal surface and optionally the incisal edge are not shown. These not shown parts of the recess wall 23 may all also be configured to have a local deformability.

Figures 6a and 6b show the local deformability of the flexible recess wall 23, especially the local deformability of a recess wall leg 33, due to increasing and decreasing the pressure in the pressure chamber. As one can see, the recess wall leg 33 has, viewed along the z-axis an irregular shape, which follows the irregularities of the dental positions of the dental arch 1. For illustrative purpose, the irregular shape of the recess wall leg 33 almost precisely mates with the irregular shape of the dental arch 1 adjacent the recess wall leg 33. As will be clear, the irregular shape of the recess wall leg 33 may be less pronounced than the irregular shape of the dental arch 1.

Figures 6a and 6b show the recess wall leg 33 in increased pressure condition. The main direction of the pressure on recess wall leg 33, as shown in figures 6a and 6b, is in the direction of the x-axis. When decreasing pressure, the recess wall leg 33 moves away from the dental arch 1, decreasing the pressure exerted by the tufts 29 on the tooth 40. When increasing pressure on the recess wall leg 33 again, the recess wall leg 33 moves towards the dental arch 1. This alternating movement in the direction of the x-axis is the first dimension of the brushing movement realized with the mouth piece according to the invention.

When decreasing the pressure on the flexible recess wall leg 33, the flexible recess wall leg 33 will not only move away from the dental arch 1, but, due to the local deformability, the flexible recess wall leg 33 will also tend to return to a less pronounced irregular shape in the decreased pressure condition. This less pronounced irregular shape which may be a continuously curved shape parallel to the z-axis in case the flexible wall part moves sufficiently far away from the dental arch or may be or a shape still with relief, but with less relief then in the increased pressure condition. This local change of the shape of the recess wall 23/recess wall leg 33 causes the tufts 29 attached at or near that location to rotate around the y-axis resulting in a sweeping along the facial surface of the teeth in the zdirection. When increasing the pressure on the flexible recess wall leg 33, the tufts 29 will tend to return to the position as shown in figures 6a and 6b, resulting in sweeping along the facial surface of the teeth in the opposite z-direction. This alternating sweeping movement in the direction of the z-axis - which sweep is indicated by the double arrow 41 in figures 6a and 6b - is due to the local deformability of the flexible wall part and is the second dimension of the brushing movement realized with the mouth piece according to the invention.

The sweeping movement 41 in the direction of the z-axis, around the y-axis, is caused by local irregularities of the dental arch 1 in the direction of the z-axis and the local deformation of the flexible wall part - at the location of the local irregularities, upon increasing and decreasing pressure.

As shown schematically in figure 6c, irregularities of the dental arch 1 in the direction of the y-axis y and the local deformability of the flexible recess wall leg 33 of the flexible recess wall 23 will, similarly, cause the tufts 29 to sweep in the y-direction around the z-axis, when increasing and decreasing the pressure in the pressure chamber 35. This alternating sweeping movement in the direction of the y-axis and around the z-axis - which sweep is indicated by the double arrow 42 in figure 6c - is due to the local deformability of the flexible wall part and is the third dimension of the brushing movement realized with the mouth piece according to the invention.

Referring to figure 6d, the local deformability of the recess wall all together results in, at least, an additional 2-dimensional brushing action which is indicated in figure 6d by the cone 43. This additional 2-dimensional brushing action is on top of the brushing action(s) already caused by the pulsating pressure. The main brushing action caused by the pulsating pressure is indicated in figure 6d by the double arrow 44 and has been described above in relation to figures 2-5. The arrow 44 representing a third dimension, the overall brushing action at the location L in figure 6d thus is a 3-dimensional brushing action: back and forth pivoting of bristles around the y-axis, back and forth pivoting of bristles around the z-axis and back and forth translating of bristles along the x-axis. As will be clear, local deformability of the recess wall leg 33 at the lingual side and local deformability of the recess wall bottom 34 will result in similar manner in an additional 2-dimensional brushing action.

More in general and viewed at the location of the root 49 of a random bristle, the additional 2-dimensional brushing action comprises a first back and forth pivoting movement of the bristles and a second back and forth pivoting movement of the bristles, which two back and forth pivoting movements are on top of a third back and forth translation movement caused by the pulsation of the pressure in the pressure chamber. Referring to the system of orthogonal axes as shown in figure 1 and viewed at the location of a root of a bristle, the root of each random bristle will lie in an xy-plane which is perpendicular to the curved z-axis. Naming the xy-plane at the location of a root of a bristle a local xy-plane, the back and forth translation movement at the location of the root of this bristle is in this local xy-plane and thus perpendicular to the z-axis. Taking into account that the recess wall has, in this local xyplane, essentially an U-shape in correspondence with the U-shaped cross section of the recess, this back and forth translation movement is also about perpendicular to the U-shape of the recess wall in this local xy-plane. The first back and forth pivoting movement is around the z-axis at the location L of the root of the respective bristle, i.e. around a first pivot axis perpendicular to the local xy-plane. The second back and forth pivoting movements is around a second pivot axis which is perpendicular to the first pivot axis (or z-axis) as well as perpendicular to the third back and forth translation movement. Further generalizing by leaving out the bristles, the local deformability of the recess wall is such that, when reciprocatingly increasing and decreasing the pressure in a said at least one pressure chamber and encompassing said plurality of dental positions in the recess, each location of the recess wall is subjected to a first back and forth pivot movement around a first pivot axis, a second back and forth pivot movement around a second pivot axis and a back and forth translation movement along a translation axis, the first pivot axis, the second pivot axis and the translation axis being mutually perpendicular.

In addition to the above discussed first, second and third back and forth movement, it is noted that the recess wall also may allow a fourth, fifth and sixth back and forth movement which may further contribute to the brushing action. The fourth back and forth movement is a back and forth translation movement in the direction of the z-axis at the location of a root of a bristle, which may result from for example elasticity of the recess wall in the direction of the zaxis and adds a fourth dimension to the brushing movement of the bristles. The fifth back and forth movement is a back and forth translation movement in the direction of the y-axis at the location of a root of a bristle, which may result from, for example, elasticity of the recess wall in the direction of the y-axis or translation of the recess wall in the y-direction (see for example figures 10b and 11b) and adds a fifth dimension to the brushing movement of the bristles. The sixth back and forth movement is a back and forth rotation movement around the x-axis at the location of a root of a bristle, which may result from, for example, local rotation of the recess wall around the x-axis and adds a sixth dimension to the brushing movement of the bristles.

Referring to figures 7 and 8, it will become clear that the local deformability of the recess wall also results in improved interdental brushing and a more regular brushing pressure exerted on the dental positions. Both figures 7 and 8 show for illustrative purpose, part of a recess wall leg 33 acting on a side of three teeth 40 in between which interdental spaces 38 are present. Figure 7 shows the situation with a recess wall leg 33 which is configured with no local deformability, figure 7a showing a decreased pressure condition and figure 7b showing an increased pressure condition, whilst figure 8 shows the situation which a recess wall leg 33 which is, according to the first aspect of the invention, configured to have a local deformability, figure 8a showing a decreased pressure condition and figure 8b showing an increased pressure condition.

When comparing the decreased pressure condition of figure 7a with the increased pressure condition of figures 7b, it can be seen that the extent to which the interdental spaces 38 are reached by the bristles 24 is determined by the length of the bristles and the distance d from the recess wall leg 33 to the sides of the teeth 33. The minimal value for the distance d might be smaller than shown in figure 7b. But due to the recess wall leg 33 in figure 7 not being locally deformable, the recess wall leg 33 will maintain to be flat as shown in figure 7b resulting in that the distance e of the recess wall leg 33 to the deepest point of the interdental recess is large compared with the situation of figures 8a and 8b. The minimal value for the distance d as well as the distance e will be reached when the bent or straight bristles 24 in the areas 45a, 45b, 45c, which are opposite the teeth 40 and not opposite the interdental spaces 38, prevent the recess wall leg 33 from moving further in the direction of the teeth 40. Now, referring to figure 8, it will be seen that, due to the recess wall leg 33 locally deforming at locations 39 opposite the interdental spaces 38, the bristles attached at or near the locations 39 of the recess wall leg will reach much deeper into the interdental spaces, resulting in a better cleaning of the interdental spaces 38.

Further referring to the increased pressure condition of figure 7b, it will be clear that the pressure exerted by the bristles 24 in the x-axis direction varies considerable along the zaxis. At the area around an interdental position, this pressure is low and might be about zero. Referring to the increased pressure condition of figure 8b, it will be clear that the pressure exerted by the bristles 24 in the x-axis direction is much more constant along the z-axis. The higher pressure exerted by the bristles in the areas of the interdental spaces 38 according to figures 8a and 8b, results in improved cleaning of these interdental spaces 38. Further, the pressure exerted by the bristles being much more constant along the z-axis means that there the pressure inside the pressure chamber is much more representative for the pressure exerted by the bristles along the dental arch. Exceeding the maximum allowable bristle pressure exerted by the bristles on especially the vulnerable gum, can thus be prevented much more reliable.

Referring to figure 9, an example of further location 46 with local deformation of a recess wall leg 33 is shown in increased pressure condition. Such a local deformation at location 46 may be caused by the bristles 24 pushed - so to say - flat towards the recess wall leg 33 due to the local deformability of the recess wall leg 33. When decreasing pressure, this local deformation 46 may disappear or become less pronounced, allowing the bristles to - so to say - rise again. This results in further additional brushing action.

Although, the second aspect of the invention may - as elucidated above - may be achieved with the locally deformable recess wall according to the first aspect of the invention, it will be clear that the second aspect of the invention may also be realized in a different manner, for example by mounting the fixed ends of the bristles individually or grouped in tufts on an individual drive per bristle or tuft of bristles, wherein the individual drive provides the back and forth translation movement and wherein the mounting allows for the first and second back and forth pivot movement.

Figures 10 and 11 show two embodiments of the third aspect of the invention, the ‘roller bellow functionality’. Figure 10 shows a mouthpiece 120 and figure 11 shows a mouthpiece 130. Figures 10 and 11 are mutually identical, except figures 10b and 11b, where the difference between the mouthpiece 120 and mouthpiece 130 can be seen. Further the mouthpieces shown in figures 10 and 11 on the one hand and figure 3 on the other hand are identical, except for the ‘roller bellow functionality’ which is absent in the mouthpiece 110 of figure 3 and for the spacer 31 in figures 10 and 11 being a plate dividing the single pressure chamber 35 of figure 3 into two pressure chambers 35a and 35b in figures 10 and 11. The pressure chambers 35a and 35b are in fluid communication with each other, for example by means of one or more passages through the plate 31, so that the fluid in both pressure chambers 35a and 35b will have the same pressure. The spacer 31 being a plate in the mouthpieces 120 and 130 has nothing to do with the ‘roller bellow functionality’. Like in figure 3a, figures 10a and 11a show a first operational state. Like in figure 3b, figures 10b and 11b show a second operational state, the increased pressure condition. And like in figure 3c, figures 10c and 11c show a third operational state, the decreased pressure condition. Taking into account the similarities between figure 3 on the one hand and figures 11 and 12 on the other hand, figures 11 and 12 use the same reference numbers for similar parts and for more details of figures 11 and 12 reference is made to the description of figure 3. Not with standing all these similarities between figure 3 on the one hand and figures 10 and 11 on the other hand, it is noted that the ‘roller bellow functionality’ according to the third aspect can be applied without (or in combination with) the ‘local deformability functionality of the recess wall’ according to the first aspect of the invention.

According to the third aspect of the invention, the body is configured to shift the upper ends 47 of the recess wall legs 33 from inside the recess 22 to outside the recess 22 when increasing the pressure in the pressure chambers 35a and 35b. When shifting outwards the bristles 48 at the upper ends 47 of the recess wall legs 33, which bristles are called end bristles 48, are subjected to a rotational movement which topples the end bristles towards a more upright position. This is shown in the increased pressure condition of figures 10b and 11b. Further, according to the third aspect of the invention, the body is configured to shift the upper ends 47 of the recess wall legs 33 from outside the recess 22 (back) into the inside of the recess 22 when decreasing the pressure in the pressure chambers 35a and 35b. When shifting inwards the end bristles 48, the end bristles 48 are subjected to a rotational movement which topples the end bristles 48 back towards a less upright position. This is shown in the decreased pressure condition of figures 10c and 11 c as well as in the pressureless condition shown in figures 10a and 11a. By reciprocatingly increasing and decreasing the pressure in the at least one pressure chamber 35a, 35b, the end bristles 48 are subjected to a back and forth swiveling movement around an axis parallel to the z-axis as defined in figure 1.

The difference between the mouthpiece 120 of figure 10 and the mouthpiece 130 of figure 11, is that in the embodiment of figure 11, the body is further configured to elongate the recess wall legs 33 when increasing pressure in the at least one pressure chamber 35a,

35b and to shorten the recess wall legs 33 when decreasing pressure in the at least one pressure chamber 35a, 35b. The effect of this is that, viewed in the y-axis direction as defined in figure 1, the depth of the recesses 22 increases when increasing pressure and decreases when decreasing pressure. This results in additional brushing action especially at the gum around the roots of the teeth. Elongating and shortening of the legs of the recess wall may for example be realized by fastening the center of the recess wall bottom 34 with respect to the spacer 31, as has been made visible, for illustrative purpose, only in figures 11b and 11c.

Figure 12 schematically depicts a top view of an embodiment of a bristle support 50, having a net-shaped configuration, also called a meshwork. The meshwork has nodes 51 each having bristles 24 implanted therein. The meshwork further has mesh members 52, 53. Each mesh member 52, 53 extends from one node 51 to another node 51. Each said node 51 connects in this embodiment six mesh members 52, 53, but it is noted that each node may also connect another number of mesh members, like three, four or five mesh members. The nodes and a mesh members define mesh openings 55. Except the nodes provided at the side edges of the mesh work, each node will connect at least three mesh members. The bristle support 50 can lie against, or be adhered to, or be fixed to a flexible recess wall 23.

In order to allow a meshwork to follow the deformation of the flexible recess wall 23, which may be a 2 dimensional deformation as indicated in figure 18, all or part of the mesh members may be:

elastically or non-elastically stretchable in their length; and/or may be configured to break when a predetermined stretching force acting on the respective mesh member is exceeded.

In the latter case, the nodes may be attached to the flexible wall part whilst the mesh members are free from the flexible wall part.

In the meshwork of figure 12 all mesh-members may be elastically or non-elastically stretchable in their length in order to allow the meshwork to follow a deformation of the flexible recess wall to which the meshwork will be attached (not shown).

Figure 13 shows schematically a meshwork 60 with nodes 51 provided with bristles (not shown) and mesh members 61, 62. The mesh members 62 have a zig-zag configuration, allowing expansion and contraction of the meshwork 60 in one direction from the state as shown in figure 13a to the state as shown in figure 13b and vice versa, whilst the dimensions in the other direction do not change when the mesh members 61 have an unchangeable length. In case the mesh members 61 are for example elastically stretchable, also expansion and contraction of the meshwork 60 in a direction perpendicular to the arrows of figure 13b will be possible. Another way of allowing expansion and contraction of meshwork 60 in two perpendicular directions, is to provide the mesh members 61 with a zig zag-structure as well, which results in a mesh work 70 like shown in figure 14a in contracted state and in figure 14b in expanded state. This meshwork 70 has nodes provided with bristles (not shown) and zig-zag mesh members 71 and 72.

Figure 15 shows a meshwork 80 having an auxetic structure. This auxetic meshwork has nodes 51 provided with bristles (not shown) and mesh members 81, 82 and can follow deformations in two perpendicular directions from the state shown in figure 15a to the state shown in figure 15b, and vice versa.

Figure 16 shows a meshwork 90 having nodes 51 with bristles (not shown) and breakable mesh members 91 and 92. The nodes of this meshwork will be attached to the recess wall 23 with the mesh members 91 and 92 not yet broken, as shown in figure 16a. Then the recess wall 23 will be deformed and the mesh members 91 and 92 will break, resulting in the state as shown in figure 16b. As the nodes are attached to the recess wall 23, the nodes will follow all subsequent deformations of the recess wall once the mesh members 91 and 92 have been broken. Figure 17 shows a variant 95 of the meshwork 90 of figure 16. As indicated the mesh members 91 and 92 can be broken by exerting a pulling force along the diagonal direction.

Figure 19 schematically depicts, in a partially cut-away perspective view, a dental cleaning device 200 comprising a handle member 202 and a mouthpiece 204 coupled thereto. The mouthpiece 204 may be any mouthpiece described in this application. The handle member 202 is provided with a handle interface, and the mouthpiece 204 is provided with a mouthpiece interface configured to be detachably coupled to the handle interface. The handle member 200 comprises a battery 210 for storing electrical energy which can be fed to the battery 210 through a battery charging interface 212. The battery 210 provides energy to a printed circuit board, PCB, 214, to a main pumping unit comprising a motor 216, a transmission 218, a crank piston 220 and a piston pump 222, and to optionally a mouthwash pump 224. A mouthwash capsule 230 containing a mouthwash liquid may be removably accommodated in the handle member 200. The piston pump 222 may be a pneumatic pump. The mouthwash pump 224 may be a hydraulic pump.

A brushing valve unit 240 is included in one or more ducts 242 leading from the piston pump 222 to the mouthpiece 204, and in possible other ducts. A cleaning valve unit 250 is included in a duct 252 leading from the mouthwash pump 224 to the mouthpiece 204. The brushing valve unit 240 and the cleaning valve unit 250 comprise electronic valves which also receive energy from the battery 210. The mouthwash pump 224 is in fluid communication with the mouthwash capsule 230 through a duct 254.

The operation of the dental cleaning device 200 is controlled by the PCB 214. The PCB 214 may control the operation of the motor 216, the operation of the mouthwash pump 224, and the operation of valves comprised in the brushing valve unit 240 and in the cleaning valve unit 250. In particular, when the dental cleaning device is used for brushing at dental positions, wherein a plurality of at least five dental positions teeth of a dental arch is encompassed by the mouthpiece 204, the PCB 214 may control the dental cleaning device 200 to reciprocatingly increasing and decreasing the pressure in at least one pressure chamber provided in the body of the mouthpiece 204.

As follows from the above the term ‘pressure chamber’ as used throughout this application is a chamber in which the pressure is changed between a decreased pressure condition and an increased pressure condition. The decreased pressure condition and increased pressure condition may both be a pressure below ambient air pressure, i.e. a vacuum defined as a pressure between 0 and 1 bar. Alternatively, the decreased pressure condition and increased pressure condition may both be a pressure above ambient air pressure, or one of these pressure conditions may be about ambient air pressure whilst the other is below or above ambient air pressure.

Where in this application the terminology ‘pressure in the pressure chamber’ or similar terminology is used, it is the ‘pressure of the fluid in the pressure chamber’. It is the pressure of the fluid which acts on the recess wall to cause local deformation. The pressure of the fluid may for example be increased by supplying additional fluid into the pressure chamber or decreased by allowing fluid to leave the pressure chamber.

Taking into account the shape of the various dental positions/natural teeth, the shape of the U-shaped cross section may vary along the length direction of the recess/recess wall. In the region of the upper and or lower incisors, the U-shaped cross section may for example be V-shaped.

Where in this application the phrase ‘in a said at least one pressure chamber’ is used, this means ‘in the pressure chambers or in one or more of said at least one pressure chamber’.

Claims

Conclusions

1] Nozzle for simultaneous brushing of a multitude of dental positions; wherein the nozzle comprises a body provided with at least one recess; wherein the at least one recess has a curved longitudinal direction and a U-shaped cross-section transversely of the longitudinal direction and is arranged to comprise a plurality of at least 5 dental positions, viewed in the curved longitudinal direction;

wherein the body, per recess, has a flexible recess wall that defines the respective recess;

wherein the recess wall is optionally covered with a plurality of bristles, each having an end attached to the recess wall and extending into the recess from the recess wall;

wherein the body is provided with at least one pressure chamber adapted to contain a fluid under pressure;

wherein the body is adapted to deform the recess wall by reciprocally increasing and decreasing a pressure in the at least one pressure chamber between a reduced pressure condition and an increased pressure condition;

characterized in that the recess wall is arranged to have such a local deformability that, when the pressure in a said at least one pressure chamber is reciprocally increased and decreased, the shape of the recess wall changes locally, wherein, in increased pressure condition, the shape of the recess wall is locally adapted to the local shape of the dental positions included in the recess wall while, in the reduced pressure condition, the shape of the recess wall is less locally adapted to the local shape of the dental positions included in the recess wall.

2] Nozzle according to claim 2, wherein, viewed in the longitudinal direction along the tongue and face sides of the dental positions included in the recess wall, the recess wall has less relief in the reduced jerking condition than in the increased pressure condition.

3] Nozzle according to any of the preceding claims, wherein the local deformability of the recess wall is arranged such that the local changes in the shape of the recess wall, between the increased pressure condition and the reduced pressure condition, occur at a pressure difference in a range up to and including 2 bar, such as in a range up to and including 0.4 bar, the pressure difference being defined as the pressure in the pressure chamber at the elevated pressure condition minus the pressure in the pressure chamber at the reduced pressure condition.

Nozzle according to any one of the preceding claims, wherein, in the reduced pressure condition, the pressure in said at least one pressure chamber is higher than the atmospheric pressure.

Nozzle according to any one of the preceding claims, wherein, in the increased pressure condition, the pressure in said at least one pressure chamber is at most 2 bar relative to atmospheric pressure, such as at most 1 bar relative to atmospheric pressure.

6. Nozzle according to any one of the preceding claims, wherein, in the elevated pressure condition, the pressure in said at least one pressure chamber is at most 0.3 bar relative to atmospheric pressure, such as at most 0.2 bar relative to atmospheric pressure .

7. Nozzle according to any one of the preceding claims, wherein, in the reduced pressure condition, the pressure in said at least one pressure chamber is lower than the atmospheric pressure.

8. Nozzle according to any one of the preceding claims, wherein, in the reduced pressure condition, the pressure in said at least one pressure chamber is in the range of -0.5 to +0.2 bar relative to atmospheric pressure, such as in the range of -0.5 to 0 bar with respect to the atmospheric pressure.

9] Nozzle for simultaneous brushing of a multitude of dental positions;

wherein a system of three mutually orthogonal center lines is defined, comprising an x center line, a y center line, and a z center line, the z center line being a curved center line following the contour of a dental arc, the x center line and y-axis are perpendicular to each other and define an xy-plane that is flat and is perpendicular to the curved z-axis;

wherein the nozzle comprises a body provided with at least one recess; wherein the at least one recess has a curved longitudinal direction that extends parallel to the z-axis, has a U-shaped cross-section transversely of the longitudinal direction, and is arranged to comprise a plurality of at least 5 dental positions viewed in the curved longitudinal direction ;

wherein the body, per recess, has a recess wall which delimits the respective recess and is provided with a plurality of bristles;

each brush hair having a fixed end attached to the body at the recess wall;

each brush hair extending from the fixed end into the recess to the free end located in the recess;

the body being adapted to reciprocally subject a plurality of said fixed ends of said bristles to a first reciprocating pivotal movement about a first pivot axis, a second reciprocating movement, when said plurality of dental positions are included in the recess reciprocating pivoting movement about a second pivot axis and reciprocating translation motion along a translation axis, the first pivot axis, the second pivot axis, and the translation axis being perpendicular to each other, the the first pivot axis is parallel to the z-axis, and the second pivot axis and the translation axis extend in the xy plane.

A mouthpiece according to any one of the preceding claims, wherein the local deformability of the recess wall is such that when the pressure in a said at least one pressure chamber is reciprocally increased and decreased and that plurality of dental positions in the recess is included, each location of the The recess wall is subjected to a first reciprocating pivoting movement around a first pivot axis, a second reciprocating pivoting movement around a second pivot axis and a reciprocating translation movement along a translational movement. axis, wherein the first pivot axis, the second pivot axis, and the translation axis are perpendicular to each other.

11. Nozzle as claimed in any of the foregoing claims, wherein each brush hair is attached to the recess wall at a root of the respective brush hair, the local deformability of the recess wall being such that when the pressure in a said at least one pressure chamber is reciprocally increased and and which includes a plurality of dental positions in the recess, the root of each bristles is subjected to a first reciprocating pivot movement about a first pivot axis, a second reciprocating pivoting movement about a second pivot axis and a reciprocating translation movement along a translation axis, the first pivot axis, the second pivot axis, and the translation axis being perpendicular to each other.

12. Nozzle as claimed in any of the foregoing claims, wherein each brush hair is attached to the recess wall in a point of attachment, wherein, at each point of attachment, a local system of three mutually orthogonal axes is defined, which local system is an x-axis, y-axis and z-axis, wherein the z-axis is a curved axis defined by the curved longitudinal direction of the recess, and the x-axis and y-axis define an xy-plane perpendicular to the z-axis;

wherein the local deformability of the recess wall is such that when the pressure in a said at least one pressure chamber is reciprocally increased and decreased and that plurality of dental positions is included in the recess, the attachment points are subjected to one or more movements from the group of: a first reciprocating pivoting movement about a first pivot axis, a second reciprocating pivoting movement about a second pivot axis and a reciprocating translation movement along a translation axis; and wherein the first pivot axis is parallel to the z axis, and the second pivot axis and the translation axis are in the xy plane and are perpendicular to each other.

13. Nozzle according to one of the preceding claims, wherein the body is provided with two recesses, and wherein the openings of the U-shaped cross sections of the two recesses are turned in mutually opposite directions.

14. Nozzle according to any of the preceding claims, wherein the recess wall, transversely to the longitudinal direction, is U-shaped according to the U-shaped cross-section of the recess;

wherein the U-shape of each recess wall defines two recess wall legs extending from a recess wall bottom, each leg having a free end;

wherein the free ends of the legs are provided with end-brush hairs; and wherein the body is arranged

- to move the free ends of the legs from inside the recess to outside the recess when the pressure in said at least one pressure chamber increases, and

- to move the upper ends of the legs from outside the recess to inside the recess when the pressure in that at least one pressure chamber decreases, such that the end-bristles are subjected to a reciprocating swinging movement around a swinging axis parallel to the longitudinal direction when the pressure in a said at least one pressure chamber increases and decreases reciprocally.

15] Nozzle for simultaneous brushing of a plurality of dental positions; wherein the nozzle comprises a body provided with at least one recess; wherein the at least one recess has a curved longitudinal direction and a U-shaped cross-section transversely of the longitudinal direction and is arranged to comprise a plurality of at least 5 dental positions, viewed in the curved longitudinal direction;

wherein the recess wall is covered with a plurality of bristles, each having an end attached to the recess wall and extending into the recess from the recess wall;

wherein the recess wall, transverse to the longitudinal direction, is U-shaped in accordance with the U-shaped cross-section of the recess; and wherein the U-shape of each recess defines two recess wall legs extending from a recess wall bottom, each leg having a free end;

characterized in that the free ends of the legs are provided with end-brush hairs; and that the body is arranged

- to move the upper ends of the legs from inside the recess to the outside of the recess when the pressure in said at least one pressure chamber increases, and

16] Nozzle according to claim 14 or 15 or one of claims 1-13, wherein the body is adapted to extend the legs when the pressure in that at least one pressure chamber increases and to shorten the legs when the pressure in that at least one room.

17. Nozzle according to any of claims 14-16, wherein the body defines a reference plane parallel to the curved longitudinal direction, the free ends of the legs pointing away from the reference plane and the outside of the bottom facing the reference plane;

wherein a vertical distance is defined as a distance, measured in a direction transverse to the reference plane, from the reference plane to the free ends of the legs; and wherein the body is further arranged:

- to increase the vertical distance when a pressure in said at least one pressure chamber increases, and

- to reduce the vertical distance when a pressure in that at least one pressure chamber decreases.

18. Nozzle according to any of the preceding claims, wherein the nozzle further comprises a network attached to the recess wall; and wherein the network is formed by nodes and net members, wherein each net member extends from said node to another said node, each said node connecting at least three said net members to each other, and wherein each node one or more said bristles or bundle bears bristles.

19] Nozzle for simultaneous brushing of a multitude of dental positions; wherein the nozzle comprises a body provided with at least one recess; wherein the at least one recess has a curved longitudinal direction and a U-shaped cross-section transversely of the longitudinal direction and is arranged to comprise a plurality of at least 5 dental positions, viewed in the curved longitudinal direction; and wherein the body, per recess, has a flexible recess wall that defines the respective recess;

characterized in that the nozzle further comprises a network attached to the recess wall; and that the network is formed by nodes and net members, each net member extending from one said node to another said node, each said node connecting at least three said net members to each other, and each node one or more said bristles or a bundle bears bristles.

Nozzle according to claim 18 or 19, wherein the mesh lies in a recess of the recess wall, or is embedded in material of the recess wall, or is glued or glued to the recess wall, or is positioned in the pressure chamber and a hole in the recess wall overlaps through which the bundle of bristles protrudes externally from the recess wall.

21. Nozzle according to any of claims 18-20, wherein each respective net member has a longitudinal direction defined by an imaginary straight line between two nodes between which the respective net member extends; and wherein the net members are stretchable in their longitudinal direction or at least a part of the net members is stretchable in their longitudinal direction.

22] Nozzle according to claim 21, wherein the stretchable net members are elastically stretchable.

23] Nozzle according to claim 21 or 22, wherein the stretchable net members, viewed in the longitudinal direction of the respective net members, have a zig-zag structure adapted to provide that stretchability.

A mouthpiece according to any one of claims 18-23, wherein said net members or at least a portion of said net members is adapted to break when a predetermined force acting on those net members is exceeded.

Mouthpiece according to any of the preceding claims, wherein the at least one recess is adapted to comprise, viewed in the curved longitudinal direction thereof, the dental positions in the range from a central incisor to a first molar.

A mouthpiece according to any one of the preceding claims, wherein the at least one recess is adapted to comprise, viewed in the curved longitudinal direction thereof, the dental positions in the range from a central incisor to a second molar.

A mouthpiece according to any one of the preceding claims, wherein the at least one recess is adapted to comprise, viewed in the curved longitudinal direction thereof, the dental positions in the range from a right-hand second premolar to a left-hand second premolar.

A mouthpiece according to any one of the preceding claims, wherein the at least one recess is adapted to comprise, viewed in the curved longitudinal direction thereof, the dental positions in the range from a right-hand first molar to a left-hand first molar.

A mouthpiece according to any one of the preceding claims, wherein the at least one recess is adapted to comprise, viewed in the curved longitudinal direction thereof, the dental positions in the range from a right-hand second molar to a left-hand second molar.

Mouthpiece according to one of the preceding claims, wherein the bristles, fixed at their ends to the recess wall, are fixed with respect to the recess wall.

A mouthpiece according to any one of the preceding claims, wherein the recess wall is covered with at least 5 bristles per cm ² , such as at least 10 bristles per cm ² .

A mouthpiece according to any one of the preceding claims, wherein the recess wall, transversely to the longitudinal direction, is U-shaped in accordance with the U-previous cross-section of the respective recess;

wherein a central axis is defined as the mirror axis of the U-shape and the U-shape of the recess defines two legs that extend in the direction of the central axis; and wherein the legs are provided with bristles extending at an angle in the range of 0 ° to 90 ° with respect to the central axis.

A mouthpiece according to any one of the preceding claims, wherein the free ends of the legs are provided with bristles that extend at an angle of 30 ° to 90 ° with respect to the central axis.

A mouthpiece according to any one of the preceding claims, wherein the recess wall is elastically deformable.

A mouthpiece according to any one of the preceding claims, wherein the recess wall is adapted to be deformable with a frequency of at least 1 Hz, such as in the range of 1-20 Hz or in the range of 20-50 Hz or more.

Dental cleaning device comprising a mouthpiece according to any of the preceding claims, and a pressure and / or suction device adapted to be in fluid communication with the at least one pressure chamber and for reciprocatingly raising and lowering the pressure in the pressure chamber.

Dental cleaning device according to claim 36, wherein the pressure and / or suction device is arranged to:

• reciprocally increasing and decreasing the pressure in a said at least one pressure chamber by a pressure difference in a range up to and including 2 bar, such as in a range up to and including 0.4 bar, the pressure difference being defined as the pressure in the pressure chamber at the elevated pressure condition minus the pressure in the pressure chamber at the reduced pressure condition;

and / or • reduce the pressure in a said at least one pressure chamber to the reduced pressure condition with a pressure higher than atmospheric pressure;

and / or • increasing the pressure in a said at least one pressure chamber to an increased pressure condition of at most 2 bar relative to the atmospheric pressure;

and / or • increasing the pressure in a said at least one pressure chamber to an increased pressure condition of at most 0.3 bar relative to the atmospheric pressure, such as at most 0.2 bar relative to the atmospheric pressure;

and / or • reduce the pressure in a said at least one pressure chamber to the reduced pressure condition with a pressure lower than atmospheric pressure;

and / or • reduce the pressure in a said at least one pressure chamber to a reduced pressure condition in the range of -0.5 to +0.2 bar relative to atmospheric pressure, such as in the range of -0.5 to 0 bar relative to atmospheric pressure.

A method for operating a nozzle according to any of claims 1-35, wherein:

• the pressure in a said at least one pressure chamber is reciprocally increased and decreased by a pressure difference in a range up to and including 2 bar, such as in a range up to and including 0.4 bar, the pressure difference being defined as the pressure in the pressure chamber at the increased pressure condition minus the pressure in the pressure chamber at the reduced pressure condition;

and / or • the pressure in a said at least one pressure chamber is periodically lowered to the reduced pressure condition with a pressure higher than the atmospheric pressure;

and / or • the pressure in a said at least one pressure chamber is periodically increased to an increased pressure condition of at most 2 bar relative to the atmospheric pressure;

and / or

The pressure in a said at least one pressure chamber is periodically increased to an increased pressure condition of at most 0.3 bar relative to the atmospheric pressure, such as at most 0.2 bar relative to the atmospheric pressure;

and / or • the pressure in a said at least one pressure chamber is periodically reduced to the

10 reduced pressure condition with a pressure lower than atmospheric pressure;

and / or • the pressure in a said at least one pressure chamber is periodically lowered to a reduced pressure condition in the range of -0.5 to +0.2 bar relative to atmospheric pressure, such as in the range of -0.5 to 0 bar compared to the

Atmospheric pressure.