Oral piece for a tooth cleaning system and tooth cleaning system

Abstract

An oral piece for a tooth cleaning system and the tooth cleaning system itself are provided. The oral piece has a base and inner and outer arches. An actuator is used to impart motion to the inner and / or outer arch relative to the base. A coupling converts motion of one of the inner and outer arches in one direction relative to the base to motion of the other of the inner and outer arches in the opposite direction relative to the base. By forming the oral piece as a central stationary base surrounded by arches that follow and move with two profiles, counter-phase brushing motions along the dental arch at opposite tooth locations are enabled, increasing reach toward the molars and reducing vibration of the device in the mouth.

Description

TECHNICAL FIELD

[0001] The present invention relates to a dental cleaning system, in particular to a dental cleaning system in the form of an automated brushing system based on actuated mouthpieces. BACKGROUND

[0002] Automated tooth brushing using mouthpieces has emerged as a new technology. Several mouthpiece based dental cleaning systems are in development and in particular require short brushing times (e.g. 6-30 seconds). These systems therefore have speed and ease of use as main value drivers.

[0003] In this document the term "mouthpiece" is used to refer to the part of the cleaning system that is located in the mouth and fits over the teeth. Typically this is an arch that covers the teeth of one jaw or a pair of arches that cover the teeth of both jaws. The system typically has other components that remain outside the mouth during use. Each arch of the mouthpiece has for example a base and side walls.

[0004] Dental cleaning systems of this type include for example a mouthpiece that fits over the teeth of one or both jaws with cleaning bristles facing the teeth. The mouthpiece or bristles are driven to move or vibrate relative to the teeth to provide a brushing action.

[0005] One problem that has been found is lack of cleaning effectiveness due to insufficient coverage / reach over the posterior teeth and gum line, lack of contour following different jaw geometries, and due to limited kinetic energy delivered to the teeth.

[0006] Difficulties have also been found in providing sufficient energy transfer from the actuator to the bristles to achieve large enough bristle strokes and large amplitudes needed to remove plaque. Vibration / shaking of the jaw and head can also be a cause of discomfort.

[0007] US 8636677 for example discloses a dental cleaning system having inner and outer bands along the inner and outer surfaces of the teeth. The two bands and associated brush elements are moved towards and away from each other, vertically up / down or in small circular motion to clean the teeth.

[0008] There is a need for an improved dental cleaning system to address some or all of the above problems. SUMMARY

[0009] The invention is defined by the independent claims. The dependent claims define advantageous embodiments.

[0010] According to an example in accordance with an aspect of the invention, there is provided a mouthpiece for a dental cleaning system, comprising:

[0011] a base;

[0012] an inner arcuate portion for positioning adjacent to inner surfaces of teeth of the jaw of the user; and

[0013] an outer arcuate portion for positioning adjacent to outer surfaces of teeth of the jaw,

[0014] an actuator coupler for connecting to an actuator to impart motion to the inner arcuate portion and / or outer arcuate portion relative to the base,

[0015] wherein the base, the inner arcuate portion and the outer arcuate portion are coupled by a coupling device, wherein the coupling device converts motion of one of the inner arcuate portion and the outer arcuate portion in one direction relative to the base into motion of the other of the inner arcuate portion and the outer arcuate portion in an opposite direction relative to the base.

[0016] The mouthpiece has inner and outer arcuate portions for brushing the inner and outer surfaces of the teeth (where inner surfaces are those facing inwards into the mouth, i.e. towards the mouth, and outer surfaces are those facing outwards from the mouth, i.e. away from the mouth). Tooth cleaning bristles are attached to the arcuate portions, for example. Angled bristles can be used to reach occlusal tooth surfaces. The base forms a central stationary part. It has a tooth contact portion for the tooth occlusal surface, for example, and cleaning elements can be added to brush the occlusal tooth surface. The base is connected to the two arcuate portions. A coupling device, formed by a hinge or pivot, for example, provides an inverse coupling mechanism between the motion of the inner and outer arcuate portions. This inverse coupling mechanism helps to reach the posterior teeth and also eliminates the vibration, thus reducing the wobble of the device inside the mouth or of the user's head.

[0017] It should be noted that the actuator coupler can be fixed (so the mouthpiece cannot be detached from the associated actuator) or it can be a detachable coupler, for example allowing the cleaning of the mouthpiece separate from the actuator.

[0018] The coupling device is particularly coupled to adjacent regions of the inner and outer arcuate portions and converts motion of one of the inner and outer arcuate portions in one direction relative to the base into motion of the other of the inner and outer arcuate portions in an opposite direction relative to the base.

[0019] The separation of the base from the arcuate portions means that the user can bite down on the base without affecting the inverse motion and thus the brushing performance. Biting on the mouthpiece does not cause an increased load on the motor, for example by ensuring that the coupling device is at a different level than the tooth contact portion of the base. The arcuate portions, on which the bristles are formed, for example, are separated from the base portion defining the body of the mouthpiece.

[0020] The mouthpiece also enables the desired brushing motion along the dental arch to be achieved with sufficient energy transfer to remove plaque, stains or softer calculus.

[0021] The coupling arrangement can comprise a symmetric or asymmetric arrangement of coupling members such as flexible hinges.

[0022] The coupling arrangement comprises for example coupling members extending between the inner and outer arches, which are connected to the base at a location between the inner and outer arches. The coupling members function for example as hinges, with the pivot point of the hinges being defined where they are connected to the base. The hinges thus swing in at least one dimension around at least one pivot point to provide counter- phase relative motion between the inner and outer arches. The pivot points can be provided in different dimensions (axes) in space to provide more complex 2D or 3D motion, such as circular motion, lateral motion (with tapping) or motion along more than one axis.

[0023] The coupling arrangement is for example configured to provide actuation of the inner or outer arch at a front of the oral piece:

[0024] Along a single side-to-side axis; or

[0025] In a two-dimensional side-to-side and up-down plane.

[0026] The front of the oral piece is the area located at the front teeth.

[0027] The arches can be driven with only lateral translational motion, or more complex motion can be generated, such as up-down motion in combination with lateral strokes, for example forming a circular rotational motion. More complex motion can for example be generated by combining 1D motion such as tapping (i.e. in a direction across the teeth rather than along the teeth) with sliding motion along the teeth or 2D circular motion, which enhances the cleaning result.

[0028] In a first set of examples, the coupling arrangement comprises:

[0029] A first hinge at a rear of a first lateral side (i.e. left or right side) of the oral piece, connecting a rear of the inner arch, a rear of the outer arch and the base at the first lateral side; and

[0030] A second hinge at a rear of a second lateral side of the oral piece, connecting a rear of the inner arch, a rear of the outer arch and the base at the second lateral side.

[0031] In this design, the coupling arrangement comprises hinges at the rear of the arches on both lateral sides (i.e. one on the left side of the oral piece and one on the right side of the oral piece).

[0032] In a second set of examples, the coupling arrangement comprises:

[0033] a first hinge disposed along a first lateral side of the oral piece from a rear of the first lateral side forward, the first hinge connecting the inner arc, the outer arc, and the base on the first lateral side; and

[0034] a second hinge disposed along a second lateral side of the oral piece from a rear of the second lateral side forward, the second hinge connecting the inner arc, the outer arc, and the base on the second lateral side.

[0035] In this design, the coupling arrangement includes a hinge disposed from a rear of the arc forward, again one on each side.

[0036] The coupling arrangement can then further include a first connector between the inner arc and the outer arc at the rear of the first lateral side and a second connector between the inner arc and the outer arc at the rear of the second lateral side. These connectors maintain the desired spacing between the inner arc and the outer arc and allow for the counter-phase motion, but the counter-phase motion is generated / induced by the first and second hinges.

[0037] The first and second hinges in these designs, for example, each include:

[0038] a strut rigidly coupled to the inner arc and the outer arc with a pivot point symmetrically or asymmetrically positioned along the strut, the pivot point coupled to the base; or

[0039] a first U-shaped bend or W-shaped bend between the outer arc and at least one connection node, and a second U-shaped bend or W-shaped bend between the connection node and the inner arc, with the connection node coupled to the base.

[0040] Thus, different hinge designs can be used to generate the desired counter-phase coupling with the appropriate resiliency.

[0041] The oral piece (base, coupling arrangement, and arcs) can be formed from a single material. However, in one example, the inner arc and the outer arc are formed, for example, from a first material, and the coupling arrangement or portions of the coupling arrangement are formed from a material different from the first material. The use of different materials can enable the resiliency connection properties of the compliant system to be optimized.

[0042] The invention also provides a tooth cleaning system, the tooth cleaning system comprising:

[0043] an oral piece as defined above; and

[0044] an actuator coupled to the coupler of the oral piece.

[0045] A dental cleaning system for example comprises a frame carrying an actuator, wherein the frame is rigidly coupled to a base. The base and the frame are thus static parts of the system. The user can bite on the stationary base and the motor is fixed on the frame which is also fixed relative to the base. Therefore, all the motion is performed by the oral piece, in particular the arches, which ensures that most of the vibration energy goes into the oral piece for cleaning and minimizes the vibration energy loss in the handle.

[0046] The actuator is for example arranged in front of the oral piece (i.e. outside and in front of the user’s mouth) and coupled to the outer arches in front of the oral piece. The frame and the actuator for example form a handle of the cleaning system.

[0047] The frame is for example coupled to the outer arches by a connection allowing a rotation of the outer arches relative to the frame around a rotation axis at the back side of the oral piece in front. The rotation axis is for example a vertical axis allowing a left and right rotation. The frame thus has a rigid connection to the base and a flexible connection to the outer arches enabling the outer arches to move relative to the base.

[0048] In all examples, the actuator can comprise a motor with an eccentric coupling element connected to the outer arches. The eccentric coupling converts the rotational motor output into the desired 1D, 2D or 3D motion pattern to be applied to one of the arches. The eccentric motor can for example be integrated in a handle of the cleaning system to actuate the outer dental arches at a suitable frequency in the range of 0.5Hz - 300Hz and a stroke of about 0.5mm - 10mm to obtain a large range of reach towards the back teeth.

[0049] In another set of examples, instead of forming the actuator outside and in front of the oral piece, the actuator can be arranged in a space partially surrounded by the inner arches. It can thus be used to be positioned in the user’s mouth. This can enable a more compact device.

[0050] The coupling device can then comprise a first swivel cam and a second swivel cam at the output of the actuator, wherein:

[0051] The first swivel cam is connected to the back of the opposite lateral sides of the inner arches and the second swivel cam is connected to the back of the opposite lateral sides of the outer arches; or

[0052] The first swivel cam is connected to the back of one and the same lateral side of the inner arches and the outer arches and the second swivel cam is connected to the back of the other and the same lateral side of the inner arches and the outer arches.

[0053] These swivel cam designs enable the desired counter-phase motion to be generated directly at the output of the actuator, for example the motor.

[0054] In all examples, the tooth cleaning system can further comprise cleaning elements (silicone bristles, nylon bristles, etc.) on the inner and outer arches and on the base to enable brushing of the occlusal surfaces of the teeth.

[0055] These and other aspects of the application will become apparent upon reference to the following examples. BRIEF DESCRIPTION OF DRAWINGS

[0056] For a better understanding of the present application, and to show how it can be carried into effect, reference will now be made, purely by way of example, to the accompanying drawings in which:

[0057] Figure 1 A first example of a tooth cleaning system is shown;

[0058] Figure 2 The design of Figure 1 is shown from above;

[0059] Figure 3 The design of Figure 1 is shown more clearly with two U-shaped channels back to back to enable cleaning of the teeth of both jaws simultaneously;

[0060] Figure 4 A unit is shown which is an assembly of the U-shaped channel of the mouthpiece and the frame;

[0061] Figure 5 An exploded view of the design of Figures 1 to 4 is shown;

[0062] Figure 6 The shape of the mouthpiece and the part of the frame which connects to the outer arch of the mouthpiece are shown;

[0063] Figure 7 How the design of the mouthpiece shown in Figure 6 is used to induce counter-phase motion is shown;

[0064] Figure 8 The shape of the mouthpiece and the part of the frame which connects to the outer arch of the mouthpiece are shown for an alternative design;

[0065] Figure 9 Another alternative design of the coupling member is shown;

[0066] Figures 10A to 10C How different materials can be used in the designs of Figure 6 and Figure 8 is shown;

[0067] Figure 11 A modification of the frame to create an additional degree of freedom is shown;

[0068] Figure 12A first alternative actuator design is shown; and

[0069] Figure 13 A second alternative actuator design is shown. DETAILED DESCRIPTION

[0070] The application will be described with reference to the drawings.

[0071] It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of an oral piece for a dental cleaning system and a dental cleaning system, are intended for purposes of illustration only and are not intended to limit the scope of the application. These and other features, aspects, and advantages of the present application will become better understood from the following description, appended claims, and accompanying drawings. It should be understood that the drawings are only schematic and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the drawings for like or similar items.

[0072] The present application provides an oral piece for a dental cleaning system and a dental cleaning system itself. The oral piece has a base and inner and outer arches. An actuator is for imparting motion (i.e. movement) to the inner and / or outer arch relative to the base. A coupling converts motion of one of the inner and outer arches in one direction relative to the base to motion of the other of the inner and outer arches in the opposite direction relative to the base. By forming the oral piece as a central stationary base surrounded by arches that follow and move with two profiles (coupled by the coupling), it enables counter-phase brushing motion along the dental arch at opposing dental sites, giving increased reach towards the molars and reduced head or device wobble in the mouth.

[0073] Figure 1 A first example of a dental cleaning system is shown. The system comprises an oral piece 10 for insertion into a user's mouth and an external piece 50 for positioning outside, in front of the user's mouth. The external piece 50 serves for example as a handle for the system.

[0074] The oral piece comprises a first U-shaped channel for receiving teeth of one jaw and a second U-shaped channel for receiving teeth of the other jaw. The user bites the oral piece in the two channels with their teeth. Alternatively, the system can have only one channel, in which case cleaning can be performed one jaw at a time.

[0075] In Figure 1 One of the U-shaped channels (facing upwards) can be seen. The opposite, downwards facing U-shaped channel can be identical. The features of one of the U-shaped channels will be described.

[0076] For the illustrated U-shaped channel, the mouthpiece 10 comprises a base 12, an inner arcuate portion 14 for positioning adjacent to the inner surfaces of the teeth of the jaw of the user and an outer arcuate portion 16 for positioning adjacent to the outer surfaces of the teeth of the jaw.

[0077] The U-shaped channel of the mouthpiece fits over the teeth of the jaw, with the inner arcuate portion 14 and the outer arcuate portion 16 positioned against the inner and outer surfaces of the teeth. The user can bite on the base 12 (or an insert with cleaning elements mounted on the base; not shown), as it is stationary in use, while the inner arcuate portion 14 and the outer arcuate portion 16 are designed to move against the surfaces of the teeth in the manner explained further below. Figure 1

[0078] It should be noted that, in Figure 1 and several other figures, the cleaning bristles are omitted for clarity, as the focus of the present invention relates to motion generation and reach. The bristles or tufts can be provided on the various portions of the mouthpiece - inner arcuate portion, outer arcuate portion and stationary base - at various angles, lengths, packing densities, etc.

[0079] There can be bristles on the base for the occlusal surfaces of the teeth, or bristles can reach across from the sides to contact the occlusal surfaces. Preferably, tooth contact portions with cleaning elements (bristles) are added on top of the base to enable brushing of the occlusal tooth surfaces.

[0080] The outer part 50 has an actuator 52 for applying motion to the inner arcuate portion and / or the outer arcuate portion relative to the base. For a system with two U-shaped channels, a common actuator is used. In this example, the actuator 52 is in front of the mouthpiece, so it is most simply connected to the outer arcuate portion 16, as shown. However, it can be connected to the inner arcuate portion 14. Similarly, in other examples where the actuator is inside the mouth of the user, in the U-shaped space formed by the inner arcuate portion, the actuator can most easily be connected to the inner arcuate portion rather than the outer arcuate portion.

[0081] The base 12, the inner arcuate portion 14 and the outer arcuate portion 16 are coupled by coupling means 18, 20. The coupling means 18, 20 convert motion of one of the inner arcuate portion and the outer arcuate portion relative to the base in one direction into motion of the other of the inner arcuate portion and the outer arcuate portion relative to the base in the opposite direction. In particular, each coupling means is connected between adjacent regions of the inner arcuate portion and the outer arcuate portion. The regions are adjacent in that they are located at the same angular position around the jaw. The coupling means is connected between those adjacent regions. The coupling means performs a pivoting function, for example.

[0082] Thus, in Figure 1 ​In the example shown, the actuator 52 imparts motion to the outer arch 16, and the coupling means 18, 20 convert this motion into counter-phase motion (i.e. in the opposite direction) of the inner arch.

[0083] By "opposite direction" it is not necessarily meant a completely opposite motion vector. Rather, one direction typically spans the edge surface of the teeth from one side of the jaw to the other (e.g. from right to left), and the opposite direction typically spans the edge surface of the teeth from the other side of the jaw to one side of the jaw (e.g. from left to right).

[0084] The coupling means 18, 20 are not clamped when the user bites down, but are free to move. This can be achieved by providing the coupling means at a different level than the tooth contact portion of the base 12.

[0085] Thus, the cleaning system has inner and outer arches for brushing the inner and outer surfaces of the teeth. The base is a central, stationary part. The counter-phase coupling helps to reach the back molars, and also eliminates vibrations, thus reducing the wobble of the device within the mouth.

[0086] The separation of the base from the arches means that the user can bite down on the base without affecting the brushing performance. Biting on the mouthpiece does not cause an increase in load on the motor, and so does not inhibit the drive vibrations. The system enables the desired brushing motion along the dental arch to be achieved with sufficient energy transfer to remove plaque and stains.

[0087] The coupling means comprises coupling members 18, 20, each extending between the inner arch 14 and the outer arch 16. Each coupling member 18, 20 is connected to the base 12 at a location 22 between the inner and outer arches via a flexible strut or web. The coupling members 18, 20 and the flexible strut act as a hinge, the primary pivot point of which is defined at a point on the flexible connection member extending between the base 12 and the location 22 at which the coupling members are connected to the base. Thus, the hinge swings about the pivot point to provide counter-phase motion of the inner and outer arches. Some pivoting at the connections between the ends of the coupling members and the inner and outer arches allows the overall arrangement to have the required flexibility.

[0088] Figure 1 The actuator 52 is shown mounted in a frame 54. The frame 54 is rigidly coupled to the base 12 by a support plate 55 (shown more clearly in other figures), such that the base and frame are static parts of the system.

[0089] The frame 54 is also connected to the outer arch 16 by branches 56. These branches 56 provide a moveable coupling between the main body of the frame and the outer arch 16. In particular, the branches 56 allow the outer arch to rotate about an axis of rotation 58 behind the front of the mouthpiece relative to the frame 54. This motion is shown by arrow 60.

[0090] In Figure 1 the example, the coupling arrangement comprises a first coupling member in the form of a hinge 18 provided along a first lateral side of the mouthpiece (left side of the user's jaw) from a rear of the first lateral side forward. This first hinge 18 connects the inner and outer arches and the base at the first lateral side. A second hinge 20 is provided along the other lateral side of the mouthpiece (right side of the user's jaw) from a rear of the other lateral side forward. The second hinge 20 connects the inner and outer arches and the base at the second lateral side. Thus, the coupling arrangement comprises hinges provided from the rear of the arches forward.

[0091] The coupling arrangement additionally has a first connector 24 between the inner and outer arches 14, 16 at the rear of the first lateral side and a second connector 26 between the inner and outer arches at the rear of the second lateral side. These connectors 24, 26 maintain the desired separation between the inner and outer arches and allow the transmission of the counter-phase motion, but the counter-phase motion is initially generated by the first and second hinges 18, 20.

[0092] The actuator 52 in this example comprises a motor with a rotating output shaft. An eccentric coupling 57 converts the rotation into the desired motion of the outer arch 16. This desired motion can be a simple lateral oscillation (i.e. from left to right), or it can be a more complex motion such as a motion in a 2D plane (i.e. from left to right and up and down, i.e. in the vertical plane of the normal orientation of the device), such as a circular motion. It can even be a 3D motion, with a component in the 2D plane (vertical plane) and a component parallel to the output shaft axis. This can be used to provide an additional tapping effect.

[0093] Thus, in the most basic example, the actuator applies a lateral one-dimensional translational motion, providing motion of the arches along a single edge-to-edge axis. However, more complex motions are possible. A combination of tapping motion (i.e. in a direction across rather than along the teeth) and sliding motion can enhance the cleaning effect.

[0094] The eccentric motor can for example be integrated in the handle of the mouthpiece to actuate the outer arch with a suitable frequency in the range of 0.5-300 Hz and a stroke of about 0.5-10 mm to obtain a large range of reach towards the back teeth.

[0095] Figure 2 The design is shown from above. Figure 1

[0096] Figure 3 The design is shown more clearly. Figure 1 ​The design of the mouthpiece 10 has two U-shaped channels 10a, 10b back-to-back to enable simultaneous cleaning of the teeth of both jaws. And the cleaning elements, e.g. bristles 70, protrude inward (towards the teeth) from the inner and outer arches.

[0097] There is a single common actuator 52, two back-to-back U-shaped channels 10a, 10b and two separate frames 54a, 54b.

[0098] Figure 4 One unit is shown, which is an assembly of one U-shaped channel 10a of the mouthpiece 10 and one frame 54a (which is connected to the outer arch). It does not include the support plate 55 as a separate component.

[0099] Figure 5 An exploded view of the design of the mouthpiece 10 is shown. Figures 1 to 4

[0100] The support plate 55 carries the actuator 52 and it is clamped between the first frame 54a and the second frame 54b. The support plate has a mounting area 80 to which the bases 12a, 12b of the two U-shaped channels 10a, 10b of the mouthpiece 10 are connected. The two bases and the mounting area are clamped together, e.g. with bolts or screws.

[0101] Figure 6 The shape of the mouthpiece 10 and the part of the frame 54 connected to the outer arch of the mouthpiece are shown, and how counter- phase motion is induced by pairs of arrows pointing in different directions along the arches. The motion of the solid arrows happens at the same time, while the motion of the dashed arrows happens at a subsequent time. This enables simultaneous cleaning of the teeth of both jaws. Figure 8 The alternative example shown can be compared.

[0102] Figure 7 How counter-phase motion is induced using the design of the mouthpiece shown is shown. Figure 6

[0103] The actuator induces lateral motion as shown by the pairs of arrows 90. The coupling member 20 has a primary hinge pivot point at some point on the flexible connection between the base 12 and the location 22. In this example, the hinge point is positioned asymmetrically between the inner and outer arches (although a symmetric arrangement is also possible, as shown below). Thus, the motion of the outer arch is amplified (based on the ratio between the distances 92a, 92b). This compensates for the loss of motion caused by the loss in the flexible hinge structure.

[0104] Thus, the asymmetric hinge design improves the transmission of motion between the outer and inner arches.

[0105] ​​As a general indication of the approximate range of motion that can be used, the reverse phase motion amplitude can be of the order of 1 mm to 5 mm. For example, the actuation amplitude can be about ±1.2 mm, the actuation input ±1.5 mm. Greater actuation amplitudes can be used, for example about 3 mm - 4 mm (half the width of the molar), for example using a geared motor.

[0106] In Figures 1 to 7 In the example of Figs. 1 - 3, the hinge of the coupling device is disposed forwardly of the rear of the mouthpiece, and there is a single connector 24. Figures 1 to 7 An advantage of the example of Figs. 1 - 3 is that the coupling member transfers motion from the outer arch to the inner arch close to the actuator. This minimises motion loss and allows the molar portion to conform to the teeth.

[0107] Figure 8 An alternative design is shown in which the coupling device comprises a first hinge 18 at the rear of a first lateral side (left side) of the mouthpiece. The first hinge 18 connects the rear of the inner arch 14, the rear of the outer arch 16 and the rear of the base 12 at the first lateral side. A second hinge 20 is located at the rear of the opposite lateral side (right side) of the mouthpiece. The second hinge connects the rear of the inner arch 14, the rear of the outer arch 16 and the rear of the base 12 at the opposite lateral side. This construction has fewer complex components.

[0108] In this example, the hinges are shown as symmetrical, with the primary pivot point located midway between the inner and outer arches. It will be appreciated that different hinge designs are possible with symmetrical or asymmetrical positioning of the primary hinge.

[0109] The above examples make use of a coupling member formed as a first U-shaped coupler between the outer arch and the location 22 where the strut connecting to the base is present, and a second U-shaped coupler between the location 22 and the inner arch. An alternative design makes use of a first W-shaped coupler and a second W-shaped coupler.

[0110] Figure 9 Another alternative design of the coupling members 18, 20 is shown. A rigid strut 100 extends between the inner and outer arches, and a pivot or rocker bearing 102 provides connection to the base 12. There is thus a T-shaped connector with a pivot point at the interconnection of the three branches of the strut.

[0111] The mouthpiece (base, coupling device and arches) can be formed from a single material. However, in one example, the inner and outer arches are formed for example from a first material, and the coupling device or parts of the coupling device are formed from a material different from the first material. The use of different materials enables optimisation of the elastic coupling performance.

[0112] Figure 10A An alternative design is shown in which the coupling device comprises a first hinge 18 at the rear of a first lateral side (left side) of the mouthpiece. The first hinge 18 connects the rear of the inner arch 14, the rear of the outer arch 16 and the rear of the base 12 at the first lateral side. A second hinge 20 is located at the rear of the opposite lateral side (right side) of the mouthpiece. The second hinge connects the rear of the inner arch 14, the rear of the outer arch 16 and the rear of the base 12 at the opposite lateral side. This construction has fewer complex components.Figure 8 The design is shown, and region A can be formed by a material (material A) that is different from the rest of the structure.

[0113] Figure 10B It shows Figure 6 The design illustrates regions B and C, which can be formed of materials different from the rest of the structure. Regions B and C can be the same material (material B), or they can be two different materials (materials B and C), both different from the main structure.

[0114] Figure 10C It shows Figure 6 The design illustrates regions D that can be formed from materials different from the rest of the structure (material D). These regions formed from different materials are the joints between the coupling member and the bow-shaped part, and the joints between the coupling member and the base.

[0115] Materials A through D have, for example, (relatively) low hardness and low Young's modulus to increase the flexibility and deformation of the hinge.

[0116] The rest of the structure is made of materials with, for example, (relatively) medium or high hardness and medium or high Young's modulus.

[0117] For example, the primary material could be polyethylene (elastic modulus of 1.1 GPa, Poisson's ratio of 0.42). While this is one option for food-grade materials used in components with a flexible design (movable hinge), other materials are also available for this application, such as polyamides (e.g., nylon) and thermoplastic elastomers.

[0118] The hinge design aims for low stress, long lifespan, and minimal energy loss in the system. These components can be manufactured, for example, by 3D printing or injection molding.

[0119] The entire system can be described as a flexible spring system. This system can, for example, be driven at its resonant frequency, thus reducing the system's power requirements. The frequency can also be individually tuned to the resonant frequency using amplitude feedback, as the damping on the teeth may vary from person to person, and components of the system can be customized for better fit.

[0120] As mentioned above, a one-dimensional reciprocating brushing motion can be used. Figure 11 A variation is shown in which branches 56 are made thinner and have slits 110 to create additional degrees of freedom in their movement. This can be used to generate 3D motion from a 2D eccentric actuator. For example, more complex (2D) circular brushing motion can be generated by actuating with a circular trajectory. Complex 3D motion, such as circular motion superimposed with a tapping motion, can be generated by adding another pivot point.

[0121] In the above examples, the actuator is in front of the mouthpiece, i.e. on the outside of the mouth. In another set of examples, instead of forming the actuator on the outside and front of the mouthpiece, the actuator can be arranged in the space partially surrounded by the inner arch. It can thus be used to be positioned on the inside of the user’s mouth. This can enable a more compact device.

[0122] One option is to use an actuator similar to the above, e.g. for driving the inner arch (which is then closer to the actuator).

[0123] As an alternative, Figure 12 An alternative actuator design is shown.

[0124] The actuator comprises a dual shaft motor 120 with rotary swash plates at the output shaft. A first rotary swash plate 122 is connected to the rear of one and the same lateral side of the inner arch 14 and the outer arch 16, and a second rotary swash plate 124 is connected to the rear of the other and the same lateral side of the inner arch and the outer arch. Each rotary swash plate thus ensures opposite movement of the common end of the inner arch and the outer arch. The two shafts rotate e.g. in the same direction.

[0125] Figure 13 Another alternative actuator design is shown.

[0126] The actuator comprises a dual shaft motor 130 with two rotary swash plates at the output shaft. A first rotary swash plate 132 driven by one shaft is connected to the rear of opposite lateral sides of the inner arch 14, while a second rotary swash plate 134 driven by the other shaft is connected to the rear of opposite lateral sides of the outer arch 16. Each rotary swash plate thus ensures opposite movement of the two ends of the respective one of the inner arch and the outer arch, and the two rotary swash plates operate opposite each other. They can e.g. rotate in opposite directions.

[0127] In this way the advantages of opposite brushing movement in combination with a larger reach can be achieved.

[0128] In Figure 12 and Figure 13 the rotary swash plate is used as a coupling device. The entire rotary swash plate design is again connected between adjacent areas of the inner arch and the outer arch (the ends in these examples), and the adjacent ends are moved in opposite directions by the overall rotary swash plate design.

[0129] The U-shaped channel of the mouthpiece allows for the addition of occlusal bristles on the fixed base. Incisor occlusion is on the front base portion to keep the stationary part stationary. This stationary part can be covered with cleaning structures (contacting the teeth) such as rough surfaces or short 0.5mm-1mm bristles to do some cleaning of the top incisors. The thickness of this stationary part can be increased in order to make room for occlusal bristles on the premolar area.

[0130] Variations of the disclosed embodiments can be understood and effected, without departing from the spirit and scope of the claimed application, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude a plurality.

[0131] The mere fact that measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0132] If the term "comprises" is used in the claims or the specification, it is noted that the term "comprises" is intended to be equivalent to the term "configured to" for the purpose of the claims.

[0133] Any reference signs in the claims should not be construed as limiting the scope.

Claims

1. An oral piece (10) for a dental cleaning system, comprising: a base (12); an inner arch (14) for positioning adjacent an inner surface of teeth of a jaw of a user; an outer arch (16) for positioning adjacent an outer surface of teeth of the jaw; an actuator coupler; and a coupling arrangement adapted to couple the base, the inner arch (14) and the outer arch (16), the coupling arrangement comprising a coupling member extending between the inner arch and the outer arch, the coupling member being connected to the base at a location between the inner arch and the outer arch, wherein the coupling arrangement couples to adjacent regions of the inner arch and the outer arch and converts movement of the region of one of the inner arch and outer arch relative to the base in one direction to movement of the region of the other of the inner arch and outer arch relative to the base in an opposite direction.

2. The oral piece of claim 1, wherein the coupling arrangement is configured to provide actuation of the inner arch or the outer arch at a front of the oral piece: along a single edge-to-edge axis; or in a two-dimensional edge-to-edge and up-down plane.

3. The oral piece of claim 1 or 2, wherein the coupling arrangement comprises: a first hinge (18) at a rear of a first lateral side of the oral piece, the first hinge connecting a rear portion of the inner arch, a rear portion of the outer arch and the base at the first lateral side; and a second hinge (20) at a rear portion of a second lateral side of the oral piece, the second hinge connecting a rear portion of the inner arch, a rear portion of the outer arch and the base at the second lateral side.

4. The oral piece of claim 1 or 2, wherein the coupling arrangement further comprises: a first hinge (18) disposed forwardly along a first lateral side of the oral piece from a rear of the first lateral side, the first hinge connecting the inner arch, the outer arch and the base at the first lateral side; and a second hinge (20) disposed forwardly along a second lateral side of the oral piece from the rear of the second lateral side, the second hinge connecting the inner arch, the outer arch and the base at the second lateral side.

5. The oral piece of claim 4, wherein the coupling arrangement further comprises a first connector (24) between the inner arch and the outer arch at the rear of the first lateral side and a second connector (26) between the inner arch and the outer arch at the rear of the second lateral side.

6. The oral piece of claim 4, wherein the first hinge and the second hinge each comprise: ​ ​ ​ a strut (100) rigidly coupled to the inner and outer arcuate portions by a pivot point (102) located along the strut, the pivot point being coupled to the base; or a first U-bend or W-bend between the outer arcuate portion (16) and a connection node (22), and a second U-bend or W-bend between the connection node (22) and the inner arcuate portion (14), wherein the connection node (22) is coupled to the base (12).

7. The mouthpiece of claim 6, wherein the inner and outer arcuate portions are formed of a first material, and the coupling device or portions of the coupling device are formed of a material different from the first material.

8. A tooth cleaning system, comprising: a mouthpiece according to any one of claims 1 to 7; an actuator coupled to the actuator coupler of the mouthpiece, wherein the actuator applies motion to the inner and / or outer arcuate portions relative to the base.

9. The tooth cleaning system of claim 8, wherein the actuator (52) is arranged in front of the mouthpiece and coupled to the outer arcuate portion (16) at the front of the mouthpiece.

10. The tooth cleaning system of claim 9, further comprising a frame (54) carrying the actuator (52), wherein the frame is rigidly coupled to the base (12), wherein the frame (54) is coupled to the outer arcuate portion (16) by a connection (56) allowing rotation of the outer arcuate portion (16) relative to the frame (54) about an axis of rotation (58) of a rear side of the front of the mouthpiece.

11. The tooth cleaning system of any one of claims 8 to 10, wherein the actuator (52) comprises a motor having an eccentric coupling element (57) connected to the outer arcuate portion (16).

12. The tooth cleaning system of claim 8, wherein the actuator (52) is arranged in a space partially surrounded by the inner arcuate portion (14).

13. The tooth cleaning system of claim 12, wherein the coupling device comprises a first swivel yoke and a second swivel yoke at an output of the actuator, wherein: the first swivel yoke is connected to a rear of opposite lateral sides of the inner arcuate portion and the second swivel yoke is connected to a rear of opposite lateral sides of the outer arcuate portion; or the first swivel yoke is connected to a rear of one same lateral side of the inner and outer arcuate portions and the second swivel yoke is connected to a rear of the other same lateral side of the inner and outer arcuate portions.

14. The tooth cleaning system according to any one of claims 8-10 and 12-13, further comprising cleaning elements (70) on the inner arch (14) and the outer arch (16), and structural cleaning elements mounted on top of the base (12).

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