Method of Manufacturing Bristled Pad and Mouthpiece for Brushing Plurality of Dental Positions, Mouthpiece and Bristle Pad
20230143045 · 2023-05-11
Assignee
Inventors
- Joppe Gideon VAN DIJK (Rotterdam, NL)
- Tim Anton SNIJDER (Rotterdam, NL)
- Thomas VAN DE WATER (Den Haag, NL)
Cpc classification
A61C17/228
HUMAN NECESSITIES
B29C65/02
PERFORMING OPERATIONS; TRANSPORTING
International classification
A61C1/00
HUMAN NECESSITIES
Abstract
The present invention relates to the manufacturing of a bristled pad for a mouthpiece toothbrush, a bristled pad, the manufacturing of a mouthpiece toothbrush with such a bristled pad, and a mouthpiece toothbrush. The bristled pad is manufactured from a prefabricated foil and prefabricated bristles. The prefabricated bristles are attached to the prefabricated pliable foil of at most 700 μm by fusing the fixed ends of the bristles with the foil. In the method of manufacturing the mouthpiece, the bristled pad is attached to the body of the mouthpiece.
Claims
1. Method of manufacturing a mouthpiece for simultaneously brushing at a plurality of dental positions, the mouthpiece being of the type comprising a body defining a recess which is lined with bristles and has a J-shaped or U-shaped length direction and an at least partly U-shaped cross-section transverse to the length direction; wherein the method comprises a pad manufacturing step in which at least one pad with bristles is made; the pad consisting of a pliable plastic foil and plastic bristles projecting from a front surface of the foil; the foil having a back surface opposite the front surface; and the pad manufacturing step comprising providing bristle with a fixed end and a free end, providing a prefabricated foil having a thickness of at most 700 μm, and fusing the fixed ends of the bristles with the prefabricated foil, resulting in the bristled pad to be made; wherein the method further comprises a body providing step in which a body of the mouthpiece to be manufactured is provided; the body providing step comprising providing a body with a recess and at least one bristle carrier; the recess having a J-shaped or U-shaped length direction and an at least partly U-shaped cross-section transverse to the length direction and being configured for encompassing a dental arch of multiple dental positions; the at least one bristle carrier delimiting the recess; and wherein the method further comprises a pad attaching step in which, during or after the body providing step, the foil of one or more bristled pads is attached to the at least one bristle carrier to line the bristle carrier with bristles such that: a) the back surface of the foil faces the bristle carrier, b) the back surface of the foil follows the shape of the surface of the bristle carrier to which it is attached, and c) the front surface of the foil faces away from the bristle carrier into the recess.
2. Method according to claim 1, wherein the prefabricated pliable foil has a thickness of at most 400 μm.
3. Method according to claim 1, wherein the prefabricated pliable foil has a thickness of at most 250 μm.
4. (canceled)
5. Method according to claim 1, wherein the bristled foil has a thickness of at most 1.5 mm.
6. Method of manufacturing a mouthpiece for simultaneously brushing at a plurality of dental positions, the mouthpiece being of the type comprising a body defining a recess which is lined with bristles and has a J-shaped or U-shaped length direction and an at least partly U-shaped cross-section transverse to the length direction; wherein the method comprises a pad manufacturing step in which at least one pad with bristles is made; the pad consisting of a pliable plastic foil and plastic bristles projecting from a front surface of the foil; the foil having a back surface opposite the front surface; and the pad manufacturing step comprising providing bristle with a fixed end and a free end, providing a prefabricated foil, and fusing the fixed ends of the bristles with the prefabricated foil, resulting in a bristled pad with a foil having a thickness of at least 1.5 mm; wherein the method further comprises a body providing step in which a body of the mouthpiece to be manufactured is provided; the body providing step comprising providing a body with a recess and at least one bristle carrier; the recess having a J-shaped or U-shaped length direction and an at least partly U-shaped cross-section transverse to the length direction and being configured for encompassing a dental arch of multiple dental positions; the at least one bristle carrier delimiting the recess; and wherein the method further comprises a pad attaching step in which during or after the body providing step one or more bristled pads are attached to the at least one bristle carrier to line the bristle carrier with bristles; the back surface side of the foil facing the bristle carrier and the front surface side of the foil facing away from the bristle carrier into the recess.
7. Method according to claim 6, wherein the pliable foil of the bristled pad has a bending resistance of less than 2 Newton, the bending resistance being defined as the force F required to bend a strip of foil having a width W of 10 mm and length L of 20 mm over a distance Q of 10 mm, the force F being directed in the direction opposite to the direction in which the free ends of the bristles are facing.
8. Method according to claim 6, wherein the mouthpiece to be manufactured has two said recesses, the J-shaped or U-shaped length directions of both recesses extending parallel and the U-shaped cross-sections of both recesses opening in mutually opposite direction, wherein the body providing step comprises providing a body with two said recesses, the J-shaped or U-shaped length directions of both recesses extending parallel and the U-shaped cross-sections of both recesses opening in mutually opposite direction, each said recess having at least one bristle carrier delimiting the respective recess; and wherein the pad attaching step comprises attaching one or more said pads to the at least one bristle carrier of each said recess.
9. Method according to claim 6, wherein the bristles comprise polybutylene terephthalate (PBT) or polyamide (PA) fibers.
10. Method according to claim 6, wherein the bristles comprise fibers of a first material and wherein the bristled surface side of the foil comprises a second material fusible with the first material.
11. (canceled)
12. Method according to claim 6, wherein, in the pad attaching step, the foil of the pad is fused with the bristle carrier.
13. Method according to claim 6, wherein the foil has a first outer layer configured to be fusible with the bristles and a second outer layer configured to be fusible with the bristle carrier.
14. Method according to claim 6,—wherein the bristle carrier is of a third material not-fusible with the bristles and/or the front surface of the foil,—wherein the foil comprises a first outer layer of a material fusible with the bristles and a second outer layer of a fourth material fusible with the third material, wherein the fourth material is a polypropylene (PP), a polyethylene (PE), a thermoplastic elastomer (TPE), or a thermoplastic polyurethane (TPU), and wherein the third material is a polypropylene (PP), a polyethylene (PE), a thermoplastic elastomer (TPE), or a thermoplastic polyurethane (TPU).
15.-21. (canceled)
22. Method according to claim 6, wherein the body comprises a pressure chamber or chain of pressure chambers extending along the length of the recess, wherein the wall of the pressure chamber at the side of the recess defines the bristle carrier, wherein the pressure chamber is configured for containing a fluid under pressure; and wherein the body is configured to move the bristle carriers to and fro with respect to the recess by reciprocatingly increasing and decreasing a pressure in the pressure chamber or chain of pressure chambers between a decreased pressure condition and an increased pressure condition.
23. Method according to claim 6, wherein the pad manufacturing step comprises the following steps: a) providing the bristles; b) providing a said prefabricated foil; c) bringing the fixed ends of the bristles in contact with the foil; d) heating the foil and/or fixed ends of the bristles; e) fusing of the fixed ends of the bristles with the foil resulting in the bristled pad.
24. Method according to claim 23, wherein the heating of step d) is by means of plastic welding and wherein step d) takes place after or before step c).
25. (canceled)
26. Method according to claim 23, wherein step a) comprises the steps of: providing a bristles holding tool having a foil support surface and a plurality of bores extending from the foil support surface into the tool, the bores being configured to receive bristles; and inserting the bristles into the bores such that their fixed ends are at the foil support surface; wherein step c) comprises placing the foil onto the foil support surface; and wherein after step e) the tool is separated from the pad.
27.-34. (canceled)
35. Mouthpiece comprising a body having a recess and at least one bristle carrier lined with bristles, the recess having a J-shaped or U-shaped length direction and an at least partly U-shaped cross-section transverse to the length direction and being configured for encompassing a dental arch of multiple dental positions, the at least one bristle carrier delimiting the recess; wherein the mouthpiece comprises one or more pads, the pad consisting of a pliable foil and bristles projecting from a front surface of the foil; the foil having a thickness of at most 400 μm; the bristles having a fixed end fused with the foil; the foil having a back surface opposite the front surface; and wherein the one or more pads are attached to the at least one bristle carrier to line the bristle carrier with bristles, the back surface side of the foil facing the bristle carrier and the front surface side of the foil facing away from the bristle carrier into the recess.
36. Mouthpiece according to claim 35, wherein the mouthpiece has two said recesses, the J-shaped or U-shaped length directions of both recesses extending parallel and the at least partly U-shaped cross-sections of both recesses opening in mutually opposite direction.
37. Mouthpiece according to claim 35, wherein the body comprises a pressure chamber or chain of pressure chambers extending along the length of the recess, wherein the wall of the pressure chamber at the side of the recess defines the bristle carrier, wherein the pressure chamber is configured for containing a fluid under pressure; and wherein the body is configured to move the bristle carriers to and fro with respect to the recess by reciprocatingly increasing and decreasing a pressure in the pressure chamber or chain of pressure chambers between a decreased pressure condition and an increased pressure condition.
38. Dental cleaning device comprising a mouthpiece according to claim 37 and a pressure and/or suction device which is configured to be in fluid communication with the pressure chamber or chain of pressure chambers and configured for reciprocatingly increasing and decreasing the pressure in the pressure chamber.
Description
BRIEF DESCRIPTION OF THE DRAWING
[0077] The invention will be explained further with reference to the drawings. In these drawings:
[0078]
[0079]
[0080]
[0081]
[0082]
[0083]
[0084]
[0085]
[0086]
[0087]
[0088]
[0089]
[0090]
[0091]
[0092]
[0093]
[0094]
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0095]
[0096] dental position 2 is the position of the left ‘second molar’, present in
[0097] dental position 3 is the position of the left ‘first molar’, missing in
[0098] dental position 4 is the position of the left ‘second premolar’, present in
[0099] dental position 5 is the position of the left ‘first premolar’, present in
[0100] dental position 6 is the position of the left ‘canine’, present in
[0101] dental position 7 is the position of the left ‘lateral incisor’, missing in
[0102] dental position 8 is the position of the left ‘central incisor’, present in
[0103] dental position 9 is the position of the right ‘central incisor’, present in
[0104] dental position 10 is the position of the right ‘lateral incisor’, present in
[0105] dental position 11 is the position of the right ‘canine’, present in
[0106] dental position 12 is the position of the right ‘first premolar’, present in
[0107] dental position 13 is the position of the right ‘second premolar’, present in
[0108] dental position 14 is the position of the right ‘first molar’, present in
In
[0109] Reference number 15 indicates the lingual side of the arc of dental positions. The lingual side 15 is the inner side of the arc of dental positions, which inner side faces the tongue. Reference number 16 indicates the facial side of the arc of dental positions. The facial side 16 is the outer side of the arc of dental positions, which outer side faces the face, like the cheeks and lips.
[0110]
[0111] Referring to the terms ‘J-shaped or U-shaped length direction’ and ‘U-shaped cross-section’ as used in the claims, the ‘J-shaped or U-shaped length direction’ is associated to the U-shaped z-axis Z in
[0112]
[0113] The full mouthpiece 20 comprises a body 21 provided with a first recess 22a. This first recess 22a has, viewed along the z-axis of
[0114] 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.
[0115] Reference 25 indicates an imaginary curved dividing line, which defines a mirror plane parallel to the xz-plane as defined in
[0116] The recesses 22a, 22b are configured to encompass an entire dental arch from the dental position of the right second or first molar to the dental position of the left second respectively first molar. The recesses 22a, 22b may also be configured to encompass a larger or smaller part of an arch of dental positions.
[0117]
[0118] As can best be seen in
[0119] As can be seen in
[0120] Inside the body there is provided a pressure chamber 35, which may, via the nipple 26 (
[0121] As can be seen in
[0122] The mouthpiece as shown in
[0123] The single pressure chamber 35 comprises a first flexible recess wall 23 delimiting the first recess 22 (the upper one in
[0124] The mouthpiece 20 is configured for the tufts 29 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 at the free ends of the recess wall legs 33 will engage the gum at the empty dental position.
[0125] Viewed in length direction Z of the dental arch—as defined in
[0126]
[0127] When the pressure in the pressure chamber 35 is in increased to an 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, the recess walls 23 are so to say compacted to narrow the recess 22, whereby the bristles 24,29, in particular the free ends thereof, may engage tooth surfaces firmly and/or may be deformed against tooth surfaces. When the pressure in the pressure chamber 35 is decreased subsequently, the recess walls are so to say widened to enlarge the recess 22. This narrowing and widening of the recess walls may be small, but when alternatingly repeated with some frequency of for example 1 to 50 Hz, this alternatingly deforming of the recess wall by alternatingly narrowing and widening it, causes the bristles to move between a firmer and relatively less firm engagement with tooth surfaces and/or the bristles to alternate between a first and second deformed condition, which in turn causes a sweeping and/or rubbing of bristles along the tooth surfaces.
[0128] By a suitable cycle of increasing and decreasing pressure in the pressure chamber 35 an 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
[0129] Referring to
[0130]
[0131] For the rest, the mouthpiece of
[0132] Moving the bristles to and fro with respect to the recess(es) is realised by means of a drive system, at least part of which is arranged in the mouthpiece. The drive system may be a mechanical system causing movement of the bristles. An example of a mechanical drive system is shown in
[0133] Now returning to the embodiment shown in
[0134]
[0135]
[0136] The definition illustrated in
[0137]
[0138] As shown in
[0139]
[0140]
[0141] Referring to
[0142]
[0143] Referring to
[0144] Referring to
[0145] Referring to
[0146] Referring to
[0147] Referring to
[0148] Referring to
[0149]
[0150]
[0151]
[0152] In the second state of
[0153] In the third state of
[0154]
[0155] Referring to the example of
[0156] Examples of embodiments of the present invention may be expressed in words as set forth in the next following clauses:
1) Method of manufacturing a mouthpiece for simultaneously brushing at a plurality of dental positions, the mouthpiece being of the type comprising a body defining a recess which is lined with bristles and has at least partly a J-shaped or U-shaped length direction and an at least partly U-shaped cross-section transverse to the length direction;
wherein the method comprises a pad manufacturing step in which at least one pad with bristles is made; the pad consisting of a pliable plastic foil and plastic bristles projecting from a front surface of the foil; the foil having a back surface opposite the front surface; and the pad manufacturing step comprising
[0157] providing bristle with a fixed end and a free end,
[0158] providing a prefabricated foil having a thickness of at most 700 μm, and
[0159] fusing the fixed ends of the bristles with the prefabricated foil, resulting in the bristled pad to be made;
[0160] wherein the method further comprises a body providing step in which a body of the mouthpiece to be manufactured is provided; the body providing step comprising providing a body with a recess and at least one bristle carrier; the recess having a J-shaped or U-shaped length direction and an at least partly U-shaped cross-section transverse to the length direction and being configured for encompassing a dental arch of multiple dental positions; the at least one bristle carrier delimiting the recess; and
[0161] wherein the method further comprises a pad attaching step in which during or after the body providing step one or more bristled pads are attached to the at least one bristle carrier to line the bristle carrier with bristles; the back surface side of the foil facing the bristle carrier and the front surface side of the foil facing away from the bristle carrier into the recess.
2) Method according to clause 1, wherein the prefabricated pliable foil has a thickness of at most 400 μm.
3) Method according to one of the preceding clauses, wherein the prefabricated pliable foil has a thickness of at most 250 μm, such as at most 150 μm.
4) Method according to one of the preceding clauses, wherein the pliable foil has a thickness of at least 50 μm.
5) Method according to one of the preceding clauses, wherein the bristled foil has a thickness of at most 1.5 mm, such as at most 1 mm or at most 750 μm.
6) Method of manufacturing a mouthpiece for simultaneously brushing at a plurality of dental positions, the mouthpiece being of the type comprising a body defining a recess which is lined with bristles and has a J-shaped or U-shaped length direction and an at least partly U-shaped cross-section transverse to the length direction;
[0162] wherein the method comprises a pad manufacturing step in which at least one pad with bristles is made; the pad consisting of a pliable plastic foil and plastic bristles projecting from a front surface of the foil; the foil having a back surface opposite the front surface; and the pad manufacturing step comprising [0163] providing bristle with a fixed end and a free end, [0164] providing a prefabricated foil, and [0165] fusing the fixed ends of the bristles with the prefabricated foil, resulting in a bristled pad with a foil having a thickness of at least 1.5 mm, such as at least 1 mm or at least 750 μm;
[0166] wherein the method further comprises a body providing step in which a body of the mouthpiece to be manufactured is provided; the body providing step comprising providing a body with a recess and at least one bristle carrier; the recess having a J-shaped or U-shaped length direction and an at least partly U-shaped cross-section transverse to the length direction and being configured for encompassing a dental arch of multiple dental positions; the at least one bristle carrier delimiting the recess; and
[0167] wherein the method further comprises a pad attaching step in which during or after the body providing step one or more bristled pads are attached to the at least one bristle carrier to line the bristle carrier with bristles; the back surface side of the foil facing the bristle carrier and the front surface side of the foil facing away from the bristle carrier into the recess.
7) Method according to one of the preceding clauses, wherein the pliable foil of the bristled pad has a bending resistance of less than 2 Newton—such as less than 1.3 Newton or less than 0.5 Newton—, the bending resistance being defined as the force F required to bend a strip of foil having a width W of 10 mm and length L of 20 mm over a distance Q of 10 mm, the force F being directed in the direction opposite to the direction in which the free ends of the bristles are facing.
8) Method according one of the preceding clauses, wherein the mouthpiece to be manufactured has two said recesses, the J-shaped or U-shaped length directions of both recesses extending parallel and the U-shaped cross-sections of both recesses opening in mutually opposite direction,
[0168] wherein the body providing step comprises providing a body with two said recesses, the J-shaped or U-shaped length directions of both recesses extending parallel and the U-shaped cross-sections of both recesses opening in mutually opposite direction, each said recess having at least one bristle carrier delimiting the respective recess; and
[0169] wherein the pad attaching step comprises attaching one or more said pads to the at least one bristle carrier of each said recess.
9) Method according to one of the preceding clauses, wherein the bristles comprise polybutylene terephthalate (PBT) or polyamide (PA) fibers, such as nylon fibers.
10) Method according to one of the preceding clauses, wherein the bristles comprise fibers of a first material and wherein the bristled surface side of the foil comprises a second material fusible with the first material.
11) Method according to clause 10, wherein the second material is a polybutylene terephthalate (PBT) or polyamide (PA), such as nylon.
[0170] 12) Method according to one of the preceding clauses, wherein, in the pad attaching step, the foil of the pad is fused with the bristle carrier.
13) Method according to one of the preceding clauses, wherein the foil has a first outer layer configured to be fusible with the bristles and a second outer layer configured to be fusible with the bristle carrier.
14) Method according to one of the preceding clauses—such as according to clause 12 in combination with clause 10—, wherein the bristle carrier is of a third material not-fusible with the bristles and/or the front surface of the foil—such as not fusible with the first material and/or second material—, wherein the foil comprises a first outer layer of a material fusible with the bristles and a second outer layer of a fourth material fusible with the third material.
[0171] 15) Method according to clause 14, wherein the fourth material is a polypropylene (PP), a polyethylene (PE), a thermoplastic elastomer (TPE), or a thermoplastic polyurethane (TPU).
16) Method according to clause 14 or 15, wherein the third material is a polypropylene (PP), a polyethylene (PE), a thermoplastic elastomer (TPE), or a thermoplastic polyurethane (TPU).
17) Method according to one of the preceding clauses, wherein the bristle carrier comprises a polypropylene (PP), a thermoplastic elastomer (TPE), or a thermoplastic polyurethane (TPU).
18) Method according to one of the preceding clauses, wherein the foil is of a non-elastic material.
19) Method according to one of the preceding clauses, wherein the foil is of an essentially inextensible material.
20) Method according to one of the preceding clauses, wherein the bristle carrier is of a flexible, elastic material.
21) Method according to one of the preceding clauses, wherein the body further comprises at least part of a driving system configured for moving, such as reciprocatingly moving, the bristles provided in the recess with respect to the rest of the body.
22) Method according to one of the preceding clauses, wherein the body comprises a pressure chamber or chain of pressure chambers extending along the length of the recess, wherein the wall of the pressure chamber at the side of the recess defines the bristle carrier, wherein the pressure chamber is configured for containing a fluid under pressure; and wherein the body is configured to move the bristle carriers to and fro with respect to the recess by reciprocatingly increasing and decreasing a pressure in the pressure chamber or chain of pressure chambers between a decreased pressure condition and an increased pressure condition.
23) Method according to one of the preceding clauses, wherein the pad manufacturing step comprises the following steps:
a) providing the bristles;
b) providing a said prefabricated foil;
c) bringing the fixed ends of the bristles in contact with the foil;
d) heating the foil and/or fixed ends of the bristles;
e) fusing of the fixed ends of the bristles with the foil resulting in the bristled pad.
24) Method according to clause 23, wherein the heating of step d) is by means of plastic welding.
25) Method according to one of the clauses 23-24, wherein step d) takes place after or before step c).
26) Method according to one of the clauses 23-25,
wherein step a) comprises the steps of:
[0172] providing a bristles holding tool having a foil support surface and a plurality of bores extending from the foil support surface into the tool, the bores being configured to receive bristles; and
[0173] inserting the bristles into the bores such that their fixed ends are at the foil support surface;
wherein step c) comprises placing the foil onto the foil support surface; and
wherein after step e) the tool is separated from the pad.
27) Mouthpiece obtained with the method according to one of the clauses 1-26.
28) Method of manufacturing a bristled pad consisting of a pliable plastic foil and plastic bristles projecting from a front surface of the foil, and the foil having a back surface opposite the front surface;
[0174] wherein the method comprises the following steps:
a) providing bristles with a fixed end and a free end;
b) providing a prefabricated foil having a thickness of at most 700 μm, such as a thickness of at most 400 μm or at most 250 μm or at most 150 μm;
c) bringing the fixed ends of the bristles in contact with the foil;
d) heating the foil and/or fixed ends of the bristles;
e) fusing of the fixed ends of the bristles with the foil resulting in the bristled pad.
29) Method according to clause 28, wherein the bristled foil has a thickness of at most 1.5 mm, such as at most 1 mm or at most 750 μm.
30) Method according to clause 28 or 29, wherein step a) comprises the steps of:
[0175] providing a bristles holding tool having a foil support surface and a plurality of bores extending from the foil support surface into the tool, the bores being configured to receive bristles; and
[0176] inserting the bristles into the bores such that their fixed ends are at the foil support surface;
wherein step c) comprises placing the foil onto the foil support surface; and
wherein after step e) the tool is separated from the pad.
31) Method according to one of the clauses 28-30, wherein the heating of step d) is by means of plastic welding.
32) Method according to one of the clauses 28-31, wherein step d) takes place after or before step c).
33) Method according to one of the clauses 28-32, wherein the pliable foil of the bristled pad has a bending resistance of less than 2 Newton—such as less than 1.3 Newton or less than 0.5 Newton—, the bending resistance being defined as the force F required to bend a strip of foil having a width W of 10 mm and length L of 20 mm over a distance Q of 10 mm, the force F being directed in the direction opposite to the direction in which the free ends of the bristles are facing.
34) Bristled pad obtained with the method according to one of clauses 28-33.
35) Mouthpiece comprising a body having a recess and at least one bristle carrier lined with bristles, the recess having a J-shaped or U-shaped length direction and an at least partly U-shaped cross-section transverse to the length direction and being configured for encompassing a dental arch of multiple dental positions, the at least one bristle carrier delimiting the recess;
[0177] wherein the mouthpiece comprises one or more pads, such as one or more bristled pads obtained according to one of clauses 24-26, the pad consisting of a pliable foil and bristles projecting from a front surface of the foil; the foil having a thickness of at most 400 μm; the bristles having a fixed end fused with the foil; the foil having a back surface opposite the front surface; and
wherein the one or more pads are attached to the at least one bristle carrier to line the bristle carrier with bristles, the back surface side of the foil facing the bristle carrier and the front surface side of the foil facing away from the bristle carrier into the recess.
36) Mouthpiece according to clause 35, wherein the mouthpiece has two said recesses, the J-shaped or U-shaped length directions of both recesses extending parallel and the at least partly U-shaped cross-sections of both recesses opening in mutually opposite direction.
37) Mouthpiece according to clause 35 or 36, wherein the body comprises a pressure chamber or chain of pressure chambers extending along the length of the recess, wherein the wall of the pressure chamber at the side of the recess defines the bristle carrier, wherein the pressure chamber is configured for containing a fluid under pressure; and wherein the body is configured to move the bristle carriers to and fro with respect to the recess by reciprocatingly increasing and decreasing a pressure in the pressure chamber or chain of pressure chambers between a decreased pressure condition and an increased pressure condition.
38) Dental cleaning device comprising a mouthpiece according to clause 37 and a pressure and/or suction device which is configured to be in fluid communication with the pressure chamber or chain of pressure chambers and configured for reciprocatingly increasing and decreasing the pressure in the pressure chamber.