Plaque detection device for detecting plaque on a surface of a tooth

Abstract

This invention relates to a plaque detection device for detecting dental plaque on the surface of teeth. The plaque detection device includes a mechanical probe comprising a probe tip configured to move along the surface of a tooth and including a first surface and a second surface. The first surface is configured to move along the surface of the tooth, and the second surface is directed away from the surface of the tooth. The plaque detection device also includes an optical sensor directed toward the second surface of the probe tip and configured to detect light reflected and / or emitted from the second surface of the probe tip. The plaque detection device further includes a processing unit configured to receive a signal from the optical sensor indicating the light reflected and / or emitted from the second surface of the probe tip, and configured to determine the presence of dental plaque on the surface of the tooth based on changes in the light reflected and / or emitted from the second surface of the probe tip.

Description

Technical Field

[0001] This invention relates to a plaque detection device for detecting plaque on the surface of teeth, an oral care device including the plaque detection device, and a method for detecting plaque on the surface of teeth using the plaque detection device. Background Technology

[0002] Dental plaque detection is a key requirement in oral health. It has the potential to be a breakthrough feature in oral health because it provides toothbrush users with feedback on where they can brush better or for longer periods. Several techniques for detecting dental plaque are known, but these can have many drawbacks and are not easily implemented. For example, techniques involving staining or fluorescent staining, and examining teeth after staining using a mirror or camera, require additional steps and consumables after brushing. Furthermore, stains can remain temporarily on the teeth. Red autofluorescence plaque imaging requires blue light illumination, filters, a camera, and image analysis, but it only displays a small portion of the plaque, and not all users have this specific type of plaque. Therefore, reliable and comfortable dental plaque detection remains a challenging task.

[0003] Plaque detection should ideally be performed during brushing, as current techniques fail to satisfactorily address this issue. Brushing-time plaque detection should address the following: it should work without any contrast agents, as users generally dislike applying additional consumables to their teeth; and it should detect all plaque types, particularly newer plaque. Preferably, it should also detect the location of plaque, allowing for the creation of plaque maps or images.

[0004] US5230621A discloses an apparatus and method for removing deposits from the subgingival tooth surface under endoscopic guidance without surgical cutting of the gingiva.

[0005] US2013 / 203008A1 discloses an oral health testing device that uses excited radiation during normal brushing to detect tooth deposits on teeth, such as plaque, cavities, bacterial infections, and tartar.

[0006] Therefore, the inventors of the present invention have found it advantageous to provide an improved device for detecting dental plaque on the surface of teeth, which does not have the aforementioned disadvantages and preferably provides reliable and comfortable plaque detection during brushing. Summary of the Invention

[0007] One object of the present invention is to provide an improved dental plaque detection device that can operate without any contrast agent, detect all types of dental plaque, and can be performed during brushing.

[0008] The object of the invention is achieved by the subject matter of the independent claims, wherein further embodiments are included in the dependent claims.

[0009] The described embodiments similarly relate to a plaque detection device for detecting plaque on the surface of teeth, an oral care device including the plaque detection device, and a method for detecting plaque on the surface of teeth using the plaque detection device. The further described embodiments can be combined in any possible manner. Although not described in detail, different combinations of embodiments may produce synergistic effects.

[0010] Furthermore, it should be noted that all embodiments of the method of the present invention can be performed in the described order of steps; however, this is not the only or necessary order of steps for the method. Unless otherwise expressly mentioned below, the method presented herein can be performed in an alternative order of the disclosed steps without departing from the corresponding method.

[0011] According to a first aspect of the invention, a plaque detection device is provided for detecting dental plaque on the surface of a tooth. The plaque detection device includes a mechanical probe comprising a probe tip configured to move along the surface of a tooth, wherein the probe tip includes a first surface and a second surface, the first surface being configured to move along the surface of the tooth, and the second surface being guided away from the surface of the tooth. The plaque detection device further includes an optical sensor guided toward the second surface of the probe tip and configured to detect light reflected and / or emitted from the second surface of the probe tip; and a processing unit configured to receive a signal from the optical sensor indicating the light reflected and / or emitted from the second surface of the probe tip, and configured to determine the presence of dental plaque on the surface of the tooth based on changes in the light reflected and / or emitted from the second surface of the probe tip.

[0012] Therefore, dental plaque on teeth is detected by combining optical sensing or imaging with a mechanical probe that plows or scrapes plaque along the surface of the tooth. The mechanical probe includes a probe tip that moves along the surface of the tooth as the device moves relative to the tooth. The probe tip includes a first surface and a second surface, which can be two portions of a preferred curved outer surface of the probe tip, or the first and second surfaces can be separated from each other by an edge of the probe tip. Essentially, the probe tip is configured such that a portion of the probe tip can be scraped (i.e., moved in direct contact with the tooth) along the surface of the tooth, thereby plowing through dental plaque on the tooth, which may be a soft deposit layer on the tooth. This portion in direct contact with the tooth is considered the first surface of the probe tip. When plowing through the plaque, the probe tip loosens or releases at least a portion of the plaque from the tooth, which is then deposited on the probe tip, preferably on a portion or surface of the probe tip that is designed not to be in direct contact with the tooth. This portion of the probe tip that is not in direct contact with the tooth and is configured to be covered by the plaque released from the tooth is considered the second surface of the probe tip. Since it should not come into contact with the teeth, but rather accumulate plaque removed from the teeth, the second surface is directed away from the tooth surface.

[0013] For example, a mechanical probe may have a circular probe tip, or it may be an elongated probe with at least a circular or elliptical cross-section, such as the bristles of a toothbrush. In this case, both the first and second surfaces are essentially part of the same outer surface of the cylindrical probe, with one side of the probe tip contacting the tooth and the other opposite side of the probe being guided away from the tooth. The term "guided away from the tooth" should be understood to mean that when the first surface is in contact with the tooth, at least a portion of the second surface is visible and not obscured by the tooth.

[0014] As another example, the probe tip may have a substantially flat external shape, having a lower surface, i.e., a first surface, that contacts the tooth, and an upper surface, i.e., a second surface, positioned substantially opposite the first surface. In this case, the first and second surfaces may be separated from each other by more or less sharp edges of the probe tip.

[0015] Therefore, while the first surface faces the tooth surface, the second surface faces in the opposite direction, and preferably in the direction of the optical sensor. Optionally, the second surface can be directed away from the tooth at an angle, such as, for example, 45 degrees relative to the tooth surface. This can be particularly useful if the contact point between the optical sensor and the tooth relative to the probe tip is not directly above the probe tip, but rather slightly to the side in a direction parallel to the tooth surface.

[0016] The plaque detection device also includes an optical sensor guided toward a second surface of the probe tip and configured to detect light arriving at the optical sensor and originating from the second surface of the probe tip. Therefore, the optical sensor can determine the color or amount of light reflected and / or emitted from the second surface of the probe tip. Specifically, the optical sensor can be configured to detect changes in the amount of light reflected from the second surface of the probe tip. Additionally or alternatively, the optical sensor can be configured to detect changes in the amount of light emitted from the second surface of the probe tip. Thus, an increase in the amount of plaque deposited on the second surface of the probe tip alters the optical properties of the second surface and causes a change in the amount of light arriving at the optical sensor from the direction of the second surface of the probe tip. The light emitted from the probe tip can be understood as light generated by fluorescence from the probe tip and / or the plaque layer on the probe tip, as well as light generated by a luminescent probe tip.

[0017] The processing unit is configured to receive a signal from an optical sensor indicating light reflected and / or emitted from a second surface of the probe tip, and to determine the presence of dental plaque on the tooth surface based on changes in the light reflected and / or emitted from the second surface of the probe tip. Therefore, preferably, the presence of dental plaque on the tooth surface can be deduced from the presence of plaque on the second surface of the probe tip as the probe tip moves along the tooth surface and loosens dental plaque deposited on the probe tip from the tooth.

[0018] Therefore, at an abstract level, the present invention combines the mechanical manipulation of a surface with optical sensing or imaging to obtain information about the manipulated surface, particularly about the presence of soft, fragile or loose material on the surface, and can be inspired by how dentists use probes to detect dental plaque.

[0019] In one embodiment of the invention, the presence of dental plaque on the tooth surface is determined by the presence of dental plaque on the second surface of the probe tip as the probe tip moves along the tooth surface.

[0020] In one embodiment of the invention, the probe tip is configured to mechanically scrape plaque from the surface of the tooth and deposit the scraped plaque onto a second surface of the probe tip. Thus, the probe tip can be shaped such that at least a portion of the probe tip penetrates the gap between the tooth surface and the plaque layer on the tooth, and at least a portion of the plaque is removed from the tooth by depositing the removed plaque onto the probe tip. For example, the probe tip may have a V-shaped edge between the first and second surfaces to lift the plaque over the edge of the probe tip.

[0021] In one embodiment of the invention, the second surface of the probe tip includes optical properties different from those of dental plaque. The optical properties may be the reflectivity of the probe tip, which differs from the reflectivity of the dental plaque. Additionally or alternatively, the optical properties may be the fluorescence of the probe tip, which differs from the fluorescence of the dental plaque. Furthermore, the optical properties may be the luminescence, illumination, or illuminance of the probe tip, such that the light originates from the probe itself, which may include an integrated light source. All these differences in at least one optical property between the second surface of the probe tip and the dental plaque can enhance the contrast between the plaque-free portion and the plaque-covered portion of the second surface, and increase the detectability of the dental plaque by the optical sensor. In one embodiment of the invention, the second surface of the probe tip is colored black. Alternatively, the second surface of the probe tip may be colored dark or may include at least one dark surface with low reflectivity. Since dental plaque is typically whitish, this increases the contrast and thus enhances the detectability of the dental plaque.

[0022] In one embodiment of the invention, the probe tip, or at least the second surface of the probe tip, is non-fluorescent or has a fluorescence different from that of dental plaque. Since dental plaque can have green or red autofluorescence, the second surface preferably has a different color of fluorescence.

[0023] In one embodiment of the invention, the plaque detection device further includes an illumination source configured to illuminate a second surface of the probe tip. This enhances uniform illumination of the second surface of the probe tip and ensures constant illumination of the probe tip even in dark environments. In this case, the presence of whitish plaque on the preferred dark probe tip may increase the amount of light reflected from the probe tip to the optical sensor.

[0024] Additionally or alternatively, the illumination source of the plaque detection device may be integrated into the probe tip. Thus, for example, the probe may be, or at least include, an optical fiber that emits light at the probe tip, thereby creating a second surface of the luminescent probe tip. In this case, the second surface may be at least partially transparent or translucent, allowing light from inside the probe tip to pass through and reach the optical sensor. In this embodiment, the luminescence from the probe tip may be attenuated due to the presence of plaque covering the second surface.

[0025] In one embodiment of the invention, the optical sensor is a camera.

[0026] In one embodiment of the invention, the dental plaque detection device includes a plurality of mechanical probes. For example, toothbrush bristles can be used as mechanical probes.

[0027] In one embodiment of the invention, the mechanical probe includes a connecting element configured to connect the probe tip to the body of a dental plaque detection device.

[0028] In one embodiment of the invention, the connecting element is flexible, and / or the connecting element is angled relative to the longitudinal axis of the plaque detection device. Therefore, the probe tip can be connected to the body of the plaque detection device via the connecting element, which can be flexible (i.e., providing a degree of elasticity) to ensure continuous contact between the first surface of the probe tip and the surface of the tooth. Furthermore, the flexible connecting element ensures that the first surface of the probe tip contacts the tooth within a predetermined force range. Providing a connecting element angled relative to the longitudinal axis of the plaque detection device enhances the flexibility of the connecting element relative to the direction perpendicular to the tooth surface.

[0029] In one embodiment of the invention, the plaque detection device includes a removal system configured to remove plaque adhered to a second surface, and / or the second surface of the probe tip is configured to minimize the amount of plaque adhered to the second surface. Therefore, the plaque detection device can provide a jet for removing plaque from the second surface of the probe tip, or it can utilize vibration to shake plaque off the probe tip. Additionally or alternatively, the second surface of the probe tip can have a very smooth and slippery surface to prevent plaque from adhering to the second surface. Preferably, the second surface can be made of a material with low surface energy, or can include a material with low surface energy, such as, for example, polytetrafluoroethylene (PTFE).

[0030] In one embodiment of the invention, the plaque detection device further includes a position sensor configured to determine the position of the plaque detection device relative to a user's oral cavity, and a processing unit configured to provide the position of plaque on the surface of the teeth relative to the user's oral cavity. Therefore, the plaque detection device can provide a map of the user's oral cavity and indicate which areas of the teeth are still covered with plaque and should be brushed more carefully.

[0031] According to another aspect of the present invention, an oral care device is provided, comprising a plaque detection device according to any of the foregoing embodiments. Therefore, the plaque detection device can be integrated into a toothbrush or any other oral hygiene device such as a rinsing device. For example, an oral care product with plaque detection can be a toothbrush with embedded plaque detection, a rinsing device with plaque detection, an oral appliance with plaque detection, or it can be a standalone plaque detection device, for example, for use after brushing. Skin care, beauty, and shaving products can also use the present invention to detect skin deposits or properties.

[0032] According to another aspect of the present invention, a method for detecting dental plaque on the surface of a tooth using a dental plaque detection device according to any of the foregoing embodiments is provided, the method comprising the steps of: providing a dental plaque detection device according to any of the foregoing embodiments; moving the probe tip of a mechanical probe along the surface of the tooth; detecting light reflected and / or emitted from a second surface of the probe tip using an optical sensor; and determining the presence of dental plaque on the surface of the tooth using a processing unit based on changes in the light reflected and / or emitted from the second surface of the probe tip.

[0033] In one embodiment of the invention, the method further includes the steps of scraping dental plaque from the surface of the tooth and depositing the scraped dental plaque on a second surface of the probe tip.

[0034] In summary, the present invention relates to a plaque detection device for detecting dental plaque on the surface of a tooth. The plaque detection device includes a mechanical probe comprising a probe tip configured to move along the surface of a tooth and including a first surface and a second surface. The first surface is configured to move along the surface of the tooth, and the second surface is directed away from the surface of the tooth. The plaque detection device also includes an optical sensor directed toward the second surface of the probe tip and configured to detect light reflected and / or emitted from the second surface of the probe tip. The plaque detection device further includes a processing unit configured to receive a signal from the optical sensor indicating the light reflected and / or emitted from the second surface of the probe tip, and configured to determine the presence of dental plaque on the surface of the tooth based on changes in the light reflected and / or emitted from the second surface of the probe tip.

[0035] One advantage of embodiments of the present invention is that dental plaque can be reliably detected without the need for contrast agents or special liquids. Another advantage is that all types of dental plaque, including both new and old plaque, can be detected. Furthermore, when using a camera and mechanical probe array, a mapping of plaque coverage on the teeth can be performed. Since future toothbrushes may be equipped with some form of camera for other purposes, such as high-resolution site sensing or tooth and gum health sensing, this can be advantageously combined with plaque sensing according to the present invention. Another advantage is that, although toothpaste can be a noise factor, plaque detection can be performed during brushing, collecting real-time data.

[0036] These advantages are not limiting, and other advantages may be envisioned in the context of this application.

[0037] The above aspects and embodiments will become apparent from the exemplary embodiments described below and will be set forth with reference to these exemplary embodiments: Exemplary embodiments of the present invention will be described with reference to the following drawings: Attached Figure Description

[0038] Figure 1 A schematic setup of a plaque detection device for detecting plaque on the surface of teeth is shown according to an embodiment of the present invention.

[0039] Figure 2 A schematic setup of a plaque detection device for detecting plaque on the surface of teeth is shown according to another embodiment of the present invention.

[0040] Figure 3 A photograph of dental plaque on the probe tip of a dental plaque detection device according to an embodiment of the present invention is shown.

[0041] Figure 4 A schematic setup of an oral care device including a plaque detection device for detecting plaque on the surface of teeth is shown according to an embodiment of the present invention.

[0042] Figure 5 A block diagram of a method for detecting dental plaque on the surface of a tooth using a plaque detection device according to an embodiment of the present invention is shown. Detailed Implementation

[0043] Figure 1 A schematic configuration of a plaque detection device 100 for detecting plaque 110 on the surface of a tooth 120 according to an embodiment of the present invention is shown. The plaque detection device 100 includes a mechanical probe 130 having a probe tip 140, an optical sensor 150, and a processing unit 160. The probe tip 140 has a first surface 141 and a second surface 142, the first surface 141 being configured to move along the surface of the tooth 120, and the second surface 142 being guided away from the surface of the tooth 120. The probe tip 140 of the mechanical probe 130 is connected to the body 101 of the plaque detection device 100 via a connecting element 135. The optical sensor 150 is guided toward the second surface 142 of the probe tip 140 and is configured to detect light 171 reflected and / or emitted from the second surface 142 of the probe tip 140. The processing unit 160 is configured to receive a signal 151 from the optical sensor 150, which indicates light 171 reflected and / or emitted from the second surface 142 of the probe tip 140. The presence of dental plaque 110 on the surface of the tooth 120 is determined based on the change in the light 171 reflected and / or emitted from the second surface 142 of the probe tip 140.

[0044] Figure 2 A schematic arrangement of a plaque detection device 100 for detecting plaque 110 on the surface of a tooth 120 according to another embodiment of the invention is shown. In this figure, a tooth with a layer of plaque 110 on the surface of the tooth 120 is shown. When the plaque detection device 100 moves relative to the tooth, at least a portion of the plaque 110 is removed from the surface of the tooth 120 and deposited on a second surface 142 of the probe tip 140 as the mechanical probe 130, having a first surface 141 of a probe tip 140, plows or scrapes across the plaque 110 along the surface of the tooth 120. The first surface 141 and the second surface 142 may be two portions of a preferred curved outer surface of the probe tip 140, or they may be separated from each other by the edge of the probe tip 140. When the probe tip 140 plows over the dental plaque 110, at least a portion of the plaque 110 is loosened or released from the surface of the tooth 120 and then deposited on the probe tip 140, preferably on a portion or surface of the probe tip 140 that is designed not to have direct contact with the tooth, i.e., a second surface 142 of the probe tip 140 that is guided away from the surface of the tooth 120. While the first surface 141 faces the surface of the tooth 120, the second surface 142 faces in another direction, and preferably in the direction of the optical sensor 150.

[0045] Therefore, the optical sensor 150, guided toward the second surface 142 of the probe tip 140, can detect light 171 reflected and / or emitted from the second surface 142 of the probe tip 140, and can determine the color or amount of light 171 arriving at the optical sensor from the direction of the second surface 142 of the probe tip 140. Specifically, the optical sensor 150 can be configured to detect changes in the amount of light 171 arriving at the optical sensor 150 from the second surface 142 of the probe tip 140. Thus, an increase in the amount of dental plaque 110 deposited on the second surface 142 of the probe tip 140 alters the optical properties of the second surface 142, such as reflectivity, fluorescence, or luminescence, and causes a change in the amount of light 171 arriving at the optical sensor 150.

[0046] For optical detection of dental plaque 110, the mechanical probe 130, particularly the second surface 142, is preferably dark, such as black. By selecting a dark probe material, the moving plaque layer alters the probe's brightness, which can be optically measured using an optical sensor 150 or a camera. As the probe tip moves through the plaque 110, at least a portion of the second surface 142 is obscured by whitish plaque removed from the surface of the tooth 120. This obscuration can be dynamically monitored using an optical sensor 150, such as a video camera. An increase or change in the light 171 returned from the second surface 142 is used to generate a positive signal indicating the presence of plaque 110 on the probe tip and therefore on the surface of the tooth 120. Alternatively, the mechanical probe 130, particularly the second surface 142, can be translucent and illuminated from within the probe tip. Thus, light emitted from the second surface can be at least partially obscured or absorbed by the plaque on the second surface, reducing the amount of light reaching the optical sensor.

[0047] Processing unit 160 is configured to receive a signal 151 from optical sensor 150 indicating light 171 reflected and / or emitted from second surface 142 of probe tip 140. Therefore, the presence of dental plaque 110 on the surface of tooth 120 is determined based on changes in the light 171 reflected and / or emitted from second surface 142 of probe tip 140. Thus, preferably, the presence of dental plaque 110 on the surface of tooth 120 can be inferred from the presence of dental plaque 110 on second surface 142 of probe tip 140 when probe tip 140 moves along the surface of tooth 120 and loosens dental plaque 110 deposited on probe tip 140 from the tooth. Processing unit 160 can also be trained using artificial intelligence tools to identify the presence or absence of dental plaque 110 from generated optical signals or images.

[0048] The mechanical probe 130 can extend from a handle, a device head such as a brush head or nozzle, or the body 101 of the plaque detection device 100 toward the surface of the tooth 120, and may have a connecting element 135 that connects a probe tip 140 with a specially designed tip shape to the body 101 of the plaque detection device 100. Preferably, the connecting element 135 is not completely rigid, but is able to bend up and down to conform to the geometry of the tooth and maintain contact with the tooth surface, similar to toothbrush bristles. Furthermore, the connecting element 135 of the mechanical probe 130 is preferably not perpendicular to the handle or body 101, but is angled relative to the longitudinal axis 102 of the plaque detection device 100. This facilitates the bending of the mechanical probe 130 itself and thus its contour conformability. Another advantage of the angled shape is that the optical sensor 150 can image the probe tip 140 from above.

[0049] The probe tip 140 can be shaped such that at least a portion of the probe tip penetrates the gap between the surface of the tooth 120 and the plaque layer on the tooth, and removes at least a portion of the plaque 110 from the tooth by depositing the removed plaque onto the probe tip 140. For example, the probe tip 140 may have a V-shaped edge between the first surface 141 and the second surface 142 to lift the plaque 110 over the edge of the probe tip 140.

[0050] Continue to refer to Figure 2 The plaque detection device 100 may optionally include an illumination source 170 for illuminating the second surface 142 of the probe tip 140 with light 171. This enhances the uniform illumination of the second surface 142 of the probe tip 140 and ensures constant illumination of the probe tip 140 even in dark environments such as the user's mouth. Alternatively, the probe may be luminescent, such that the light source is arranged within the probe; for example, the probe may be a light-conducting probe configured to emit light at the second surface. Thus, the illumination source may be located in the handle of the plaque detection device 100, and light may be transmitted to the probe tip via a light guide, or the illumination source may be arranged at or within the probe tip. Alternatively, the probe may be wire-connected and may have a miniature illumination source located directly on the second surface. If plaque adheres to or moves above the second surface, the light will be partially blocked, and the light intensity, measured by an optical sensor, will change, indicating the presence of plaque on the second surface.

[0051] Optionally, the plaque detection device 100 may include a removal system 180 for removing plaque 110 adhered to a second surface 142, and / or the second surface 142 of the probe tip 140 may be configured to minimize the amount of plaque 110 adhered to the second surface 142. Since the plaque detection device 100 may experience reduced sensitivity during use due to plaque 110 adhering to the probe tip 140, the plaque detection device 100 may provide a fluid jet for removing plaque 110 from the second surface 142 of the probe tip, or may utilize vibration to shake plaque off the probe tip 140. Additionally or alternatively, the second surface 142 of the probe tip 140 may have a very smooth and slippery surface to prevent plaque from adhering to the second surface 142. When new plaque 110 enters the lighter area of ​​the probe, plaque may still accumulate and decrease as some plaque 110 slides off or detaches. This change in signal can indicate the presence of plaque 110 on a specific site of the tooth. Using a non-adhesive probe material (such as polytetrafluoroethylene) can further minimize plaque 110 adhering to the probe tip 140. A solution for adhering plaque 110 can also be the intermittent removal of plaque 110 from the probe tip 140. This can be accomplished, for example, by some vibration of the probe tip (which can shake off the plaque) or by a fluid jet. If the plaque detection device 100 is integrated into an oral irrigator, a fluid jet can be provided efficiently, and the jet pulses can be used to remove adhering plaque, ensuring the probe is clean when it plows into the next plaque layer.

[0052] Furthermore, the plaque detection device 100 may optionally include a position sensor 190 configured to determine the position of the plaque detection device 100 relative to the user's oral cavity. Therefore, the processing unit 160 may be configured to provide the position of plaque 110 on the surface of the teeth 120 relative to the user's oral cavity. Thus, the plaque detection device 100 can provide a map of the user's oral cavity and indicate which areas of the teeth are still covered by plaque 110 and should be brushed more carefully.

[0053] Figure 3A photograph of dental plaque 110 on the probe tip 140 of a dental plaque detection device 100 according to an embodiment of the present invention is shown. The mechanical probe 130 can simply be a standard-shaped black toothbrush bristle. Alternatively, the dental plaque detection device 100 may include multiple mechanical probes 130. In this example, toothbrush bristles are used as mechanical probes 130. To improve sensitivity, the probe tip 140 may have a specific shape, such as a thin, flat shape or a snowplow-like V-shape, because such shapes more easily penetrate beneath the plaque layer. This embodiment was tested in a laboratory. Oral biofilms were cultured on the surface of a previously extracted tooth 120. A clump of bristles was stained black, as shown in the image. Figure 3 As shown. Figure 3 The left figure shows the surface of a cleaned tooth 120 with black bristles that serve as a mechanical probe 130 with a probe tip 140. Figure 3 The right image shows the biofilm covering the surface of tooth 120 after the bristles have moved through it. The loose biofilm covers the black bristle tips, giving them a lighter shade, which can be identified using image analysis by processing unit 160 or a trained artificial intelligence algorithm. Figure 3 As shown in the photo on the right, a thin layer of dental plaque 110 covers the probe tip 140 of the mechanical probe 130.

[0054] Figure 4 A schematic arrangement of an oral care device 200 according to an embodiment of the present invention is shown, comprising a plaque detection device 100 for detecting plaque 110 on the surface of a tooth 120. Thus, plaque can be detected using a mechanical probe 130 and an optical sensor 150 to optically sense the interaction between plaque 110 and a first surface 141 and a second surface 142 of a probe tip 140. Various embodiments are conceivable: the plaque detection device 100 may be a dedicated plaque sensing tool, or it may be integrated into an oral care device 200, such as a toothbrush, oral irrigator, or brushing mouthpiece. The key components of the invention are the mechanical probe 130 and the optical sensor 150 with a processing unit 160 for analyzing the detected signals.

[0055] For example, the mechanical probe 130 may have a circular probe tip, or it may be an elongated probe with at least a circular or elliptical cross-section, such as the bristles of a toothbrush. In this case, the first and second surfaces are essentially portions of the same outer surface of the cylindrical probe, with one side of the probe tip contacting the tooth and the other opposite side of the probe being guided away from the tooth. As another example, the probe tip 140 may have a substantially flat outer shape, having a lower surface, i.e., the first surface 141, that contacts the tooth, and an upper surface, i.e., the second surface 142, positioned substantially opposite the first surface. In this case, the first and second surfaces may be separated from each other by more or less sharp edges of the probe tip 140. Alternatively, the second surface may be guided away from the tooth at an angle, such as, for example, 45 degrees relative to the surface of the tooth. This can be particularly useful if the contact point between the optical sensor 150 and the probe tip 140 and the tooth is not located directly above the probe tip 140, but rather slightly away from the side in a direction parallel to the surface of the tooth 120.

[0056] While standard bristle tip configurations can detect thicker plaque layers, in areas where the plaque layer is thinner, insufficient plaque may be moved over the bristles, which serve as the second surface 142, to detect a signal. Finer bristles can improve plaque detection, although they can become too soft at certain points unless they are actually very short and fine bristles mounted on a coarser connecting element. Other tip geometries that enable higher sensitivity could be slabs or wedge-shaped elements. Similar to a snowplow, a wedge shape can also form a V-shape in other dimensions. Such shapes can have the additional advantage that new plaque layers push away plaque adhering to the probe, exhibiting dynamic fluctuations in brightness, which can serve as another signal for plaque detection. Of course, for the user comfort of the plaque detection device, the probe tip 140 should not be too sharp.

[0057] Regarding the optical sensor 150, this could be a camera. Color is not required, and high resolution is not necessary. The camera, combined with multiple mechanical probes 130 (e.g., a row of probes), can even allow for plaque mapping on teeth. As the user moves across the teeth on the system, plaque data at different heights on the teeth is returned, and when combined with site sensing, a full-mouth plaque map can be created. The camera can also identify the gingival line and map plaque signals relative to the gingival line. A less advanced but cheaper embodiment can be achieved using a simple optical sensor. This sensor can detect the average change in light 171 returned from one or more probes, thereby detecting the average plaque level on a particular tooth. For robust optical sensing, the device can be equipped with a stable illumination source 170, such as an LED. Specific wavelengths can be selected to improve the contrast between plaque 110 and probe tip 140 or between the tooth and gingival surfaces.

[0058] One potential problem is that toothpaste used during brushing can block the light path and interfere with the detection mechanism of the optical sensor. Additional measures may be needed to remove the toothpaste from the area of ​​the probe tip, which could be, for example, a toothpaste scraper. Similarly, water or air jets can be a beneficial solution for removing blocked toothpaste, especially if a toothbrush with an integrated interdental cleaning jet is used. Alternatively, the optical sensor 150 can use images only when the toothpaste is temporarily out of the optical sensor's field of view. As the toothbrush moves, the toothpaste is moved by the bristles, and due to this mixing, areas without toothpaste often appear temporarily. Another strategy could be to occasionally use a toothbrush including the plaque detection device 100 to detect plaque even without toothpaste. For example, obtaining such plaque removal feedback once a week could be sufficient to enhance brushing techniques and improve oral health outcomes. If the plaque detection device 100 is used in an oral irrigator or a standalone plaque scanning device, the toothpaste problem is not present. Of particular interest could be a fluorescence camera or scanner for detecting potential problem areas that can exhibit red fluorescence. Red fluorescence can be emitted from aged plaque as well as tartar and cavities. Adding current plaque detection equipment 100 to this type of scanner would also make newer plaque visible, which is important for consumers. Newer plaque still has autofluorescence, not red, but an emission spectrum similar to that of teeth. Therefore, using typical violet excitation, both new plaque and teeth exhibit green fluorescence, and there is no contrast to observe the plaque. Using the present invention with a mechanical probe, one can see green fluorescent plaque moving above the probe or the probe moving below newly formed green fluorescent plaque. The probe material itself should not be fluorescent, or should have a different emission spectrum to provide contrast. In this concept, the probe can also help distinguish different sources of red fluorescence identified by the scanner. If the source is old plaque, one can also see the probe digging into that old plaque layer, but if it is tartar or cavity, the probe will simply move above that point because there is no soft plaque layer there.

[0059] In one embodiment for detecting plaque fluorescence, a specific wavelength range of excitation light from an illumination source (which illuminates the probe tip and plaque) and an optical filter in front of the optical sensor may be required to filter out these excitation wavelengths and capture only the emission wavelengths of fluorescence. For example, to detect the autofluorescence of plaque, violet to blue excitation wavelengths are typically selected in the range of 400 nm to 480 nm, as plaque generally exhibits green fluorescence at these excitation wavelengths. Older plaque may also exhibit red fluorescence, which is strongest under excitation at 400 nm to 420 nm. Using wavelengths below 400 nm is possible but less preferred because ultraviolet light can be harmful to oral tissues. The probe properties in this mode are preferably non-fluorescent. In a fluorescence image, a non-fluorescent probe will appear black, and plaque moving above the second surface of the probe will thus make that surface appear brighter, very similar to a reflective embodiment with a black probe. The probe may also have fluorescence different from the autofluorescence of the plaque, such as low or very high brightness or a different color.

[0060] The plaque detection device of this invention employs a sensing mechanism that, while detecting plaque, also partially or even completely removes it. Therefore, if the user receives a signal indicating the presence or previous presence of plaque, additional cleaning is not actually necessary. Nevertheless, it would be very useful to use such devices periodically to test the success of oral hygiene procedures and to identify areas that are consistently poorly brushed. This information can guide the user to brush their teeth better or for longer periods in specific areas.

[0061] The device according to the invention can also be used for other personal health applications, such as viewing skin properties, and more specifically, viewing deposits or loose material on the skin, such as sebum or dead skin cells. This can be applied to exfoliation, acne assessment, or shaving. Detecting deposits on other body parts, such as the skin, can also have general significance for personal health imaging based on personal health devices. On the skin, sebum deposits (associated with acne) or dead skin cells associated with exfoliation can be found.

[0062] Figure 5A block diagram of a method for detecting dental plaque 110 on the surface of a tooth 120 using a dental plaque detection device 100 according to an embodiment of the present invention is shown. The method includes step S110: providing a dental plaque detection device according to any of the foregoing embodiments; and step S120: moving the probe tip of a mechanical probe along the tooth surface. The method further includes step S130: detecting light reflected and / or emitted from a second surface of the probe tip using an optical sensor; and step S140: determining the presence of dental plaque on the tooth surface using a processing unit based on changes in the light reflected and / or emitted from the second surface of the probe tip. Alternatively, the method includes the steps of scraping dental plaque from the tooth surface and depositing the scraped dental plaque onto the second surface of the probe tip.

[0063] While the invention has been detailed and described in the accompanying drawings and the foregoing description, such description and illustration are to be regarded as illustrative or exemplary, and not restrictive. The invention is not limited to the disclosed embodiments. Other variations of the disclosed embodiments will be understood and implemented by those skilled in the art in practicing the claimed invention by studying the drawings, the disclosure, and the dependent claims.

[0064] In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude multiple. The mere fact that certain measures are listed in mutually different dependent claims does not indicate that a combination of these measures cannot be used advantageously. No reference numerals in the claims should be construed as limiting the scope. List of reference numerals in the attached diagram: 100 Dental Plaque Detection Equipment 101 Main Body 102 Longitudinal axis 110 Dental plaque 120. The surface of the teeth 130 Mechanical probe 135 Connecting element 140 probe tip 141 First Surface 142 Second Surface 150 Optical Sensor 151 signal 160 processing units 170 Light Source 171 Light 180 Remove System 190 position sensor 200 Oral Care Equipment

Claims

1. A plaque detection device (100) for detecting plaque (110) on the surface of a tooth (120), the plaque detection device (100) comprising: A mechanical probe (130) includes a probe tip (140) configured to move along a surface of a tooth (120), wherein the probe tip (140) includes a first surface (141) and a second surface (142), the first surface (141) being configured to move along the surface of the tooth (120), and the second surface (142) being directed away from the surface of the tooth (120); An optical sensor (150) is guided toward the second surface (142) of the probe tip (140) and configured to detect light (171) reflected and / or emitted from the second surface (142) of the probe tip (140). A processing unit (160) is configured to receive a signal (151) from the optical sensor (150) indicating light (171) reflected and / or emitted from the second surface (142) of the probe tip (140), and is configured to determine the presence of dental plaque (110) on the surface of the tooth (120) based on changes in the light (171) reflected and / or emitted from the second surface (142) of the probe tip; as well as The feature is that, when the probe tip (140) moves along the surface of the tooth (120), the presence of dental plaque (110) on the surface of the tooth (120) is determined by the presence of dental plaque (110) on the second surface (142) of the probe tip (140).

2. The dental plaque detection device (100) according to claim 1, wherein the probe tip (140) is configured to mechanically scrape dental plaque (110) from the surface of the tooth (120) and deposit the scraped dental plaque (110) on the second surface (142) of the probe tip (140).

3. The dental plaque detection device (100) according to any one of the preceding claims, wherein the second surface (142) of the probe tip (140) includes optical properties different from those of dental plaque.

4. The dental plaque detection device (100) according to any one of the preceding claims, wherein the second surface (142) of the probe tip (140) is colored black.

5. The dental plaque detection device (100) according to any one of the preceding claims further includes an illumination source (170) configured to illuminate the second surface (142) of the probe tip (140) with light (171).

6. The dental plaque detection device (100) according to any one of the preceding claims, wherein the optical sensor (150) is a camera.

7. The dental plaque detection device (100) according to any one of the preceding claims, wherein the dental plaque detection device (100) comprises a plurality of mechanical probes (130).

8. The dental plaque detection device (100) according to any one of the preceding claims, wherein the mechanical probe (130) includes a connecting element (135) configured to connect the probe tip (140) to the body (101) of the dental plaque detection device (100).

9. The dental plaque detection device (100) according to claim 8, wherein the connecting element (135) is flexible, and / or wherein the connecting element (135) is angled relative to the longitudinal axis (102) of the dental plaque detection device (100).

10. The dental plaque detection device (100) according to any one of the preceding claims, wherein the dental plaque detection device (100) includes a removal system (180) configured to remove dental plaque (110) adhering to the second surface (142), and / or wherein the second surface (142) of the probe tip (140) is configured to minimize the amount of dental plaque (110) adhering to the second surface (142).

11. The dental plaque detection device (100) according to any one of the preceding claims, wherein the dental plaque detection device (100) further comprises a position sensor (190) configured to determine the position of the dental plaque detection device (100) relative to a user's oral cavity, and wherein the processing unit (160) is configured to provide the position of the dental plaque (110) on the surface of the tooth (120) relative to the user's oral cavity.

12. An oral care device (200) comprising a plaque detection device (100) according to any one of claims 1 to 11.

13. A method for detecting dental plaque (110) on the surface of a tooth (120) using a dental plaque detection device (100) according to any one of claims 1 to 11, the method comprising the steps of: Provide (S110) the dental plaque detection device (100) according to any one of claims 1 to 11; The probe tip (140) of the mechanical probe (130) is moved along the surface of the tooth (120) (S120). The optical sensor (150) is used to detect (S130) the light (171) reflected and / or emitted from the second surface (142) of the probe tip (140); and The processing unit (160) uses the light (171) reflected and / or emitted from the second surface (142) of the probe tip (140) to determine (S140) the presence of dental plaque (110) on the surface of the tooth (120).

14. The method of claim 13, further comprising the step of: Dental plaque (110) is scraped off the surface of the tooth (120) and the scraped dental plaque (110) is deposited on the second surface (142) of the probe tip (140).

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