Intraoral scanning system for determining combined scanning information

Abstract

The present disclosure relates to an intraoral scanning system comprising a hand-held intraoral scanning device comprising a projection unit configured to emit light having different wavelengths including at least a near-infrared wavelength and at least a visible wavelength, an image sensor unit configured to emit light having different wavelengths including at least a near-infrared wavelength and at least a visible wavelength, and a processor configured to capture visible light information and internal light information from the at least one dental arch generated by the emitted light of the different wavelengths. The one or more processors are configured to receive visible light information and internal light information; determining surface information in real time from the visible light information in order to generate or update a three-dimensional (3D) model of the dental arch using the surface information; determining internal structure information of the dental arch from the internal light information; and determining combined scan information including a combination of the internal structure information and the visible light information.

Description

Technical Field

[0001] The present disclosure relates to an intraoral scanning system and, more particularly, to one or more processors of the system configured to determine combined scanning information including enhanced internal structure information and / or enhanced texture information of a tooth. Background Art

[0002] Many dental and orthodontic procedures can benefit from an accurate three-dimensional (3D) description of the patient's dentition and oral cavity. Specifically, providing a 3D description of both the tooth surface and the internal structure, including the enamel and dentin, as well as caries and the overall internal composition of the tooth body would be beneficial. While pure surface representation of the 3D surface of a tooth has proven extremely useful in the design and fabrication of dental restorations, such as crowns or bridges, the ability to image the internal structure, including the development of caries and cracks in the enamel and underlying dentin, would be extremely useful, especially when combined with surface morphology mapping.

[0003] Currently, state-of-the-art technology, ionizing radiation (e.g., X-rays), is used for dental imaging for diagnostic purposes. For example, X-ray bitewing radiographs are commonly used to provide non-quantitative images of the internal structure of teeth. However, in addition to the risks of ionizing radiation, such images are often limited in their ability to reveal early changes in tooth mineralization (e.g., early caries), leading to an underestimation of the depth of demineralization; they cannot assess the presence of microcavities; and they result in frequent overlap of adjacent tooth surfaces, which necessitates repeated acquisition of radiographs and can be a time-consuming and expensive procedure.

[0004] Some intraoral features, such as soft tissue and dental plaque, are generally not visible on X-rays due to their low density. Other techniques, such as cone-beam computed tomography (CBCT), can provide cross-sectional images and be used to gather more information about tissues and internal structures, but still require ionizing radiation.

[0005] In addition, near-infrared (NIR) light is known to be used to evaluate internal tooth structure and tooth surfaces by either transilluminating the tooth or reflecting and scattering light from the tooth. The NIR range provides a non-ionizing and safe method for evaluating caries, dental restorations, cracks, and enamel and dentin defects. Summary of the Invention

[0006] One aspect of the present disclosure is to improve the detection of internal structures using a non-ionizing and safe method.

[0007] Another aspect of the present disclosure is to obtain an intraoral scanning system configured to enhance visualization of dental caries in a manner that makes it easier for a dentist to identify and treat caries.

[0008] Another aspect of the present disclosure is to obtain an intraoral scanning system that is configured to enhance visualization of dental restorations in a manner that makes it easier for a dentist to identify and treat secondary caries, as well as identify the type of restoration, such as the type of filling, inlay, onlay, crown, and / or sealant.

[0009] Yet another aspect of the present disclosure is to obtain an intraoral scanning system configured to enhance visualization of the "dentin-enamel junction" (DEJ) of a tooth in a manner that makes it easier for a dentist to identify the DEJ for clinical evaluation.

[0010] Another aspect of the present disclosure is to obtain an intraoral scanning system configured to generate or update a three-dimensional 3D model while determining combined scanning information using different wavelength modalities.

[0011] In addition to enabling enhanced visualization of caries, restorations, and the dentin-enamel junction, another aspect of the present disclosure is the ability to detect early-stage caries at a stage where preventative measures can achieve remineralization, thereby restoring damage caused by caries infection before more complex restorative measures are required. Advantageously, the present disclosure can accurately detect caries infection at earlier stages than can be shown using existing fluorescence or near-infrared methods.

[0012] According to these aspects, an intraoral scanning system is disclosed. The intraoral scanning system can be configured to provide combined scan data based on captured visible light information and internal light information. The system may include a handheld intraoral scanner, which includes a projection unit configured to emit light of different wavelengths onto at least a dental arch during multiple time periods, wherein the different wavelengths include at least a near-infrared wavelength and at least a visible wavelength. The wavelength of each time period may be different. The handheld intraoral scanning device may also include an image sensor unit configured to capture visible light information and internal light information from at least the dental arch caused by the emitted light of different wavelengths. The system may also include one or more processors operably connected to the image sensor unit, the one or more processors being configured to receive the visible light information and the internal light information, and to determine surface information in real time based on the visible light information, so as to generate or update a three-dimensional (3D) model of the dental arch using the surface information. The one or more processors may be configured to determine internal structure information of the dental arch from the internal light information, and to determine combined scan information including a combination of the internal structure information and the visible light information.

[0013] Internal light information primarily includes reflections from the tooth interior, i.e., the area inside the dental object, and significantly less reflections from the tooth surface. Visible light information primarily includes reflections from the tooth surface, and significantly less reflections from the tooth interior, i.e., the area inside the dental object. Internal light information includes information about the dental condition from within the tooth, not just the tooth surface.

[0014] The combined scan information does not include the superposition of two 2D images, where each of the two 3D images is associated with a different emission wavelength from the projection unit. In this example, no enhancement of internal structure information is provided. The combined scan information can be a combination of the intensity levels of each pixel of the image sensor unit associated with different wavelengths. For example, in a first time period, the image sensor unit captures light information associated with a visible wavelength, and in a second time period, the image sensor unit captures light information associated with a near-infrared wavelength. The intensity levels of these two time periods are recorded and combined to enhance the dental condition, i.e., the internal structure information. The combination of intensity levels can be accomplished digitally by subtracting and / or adding intensity levels. In another example, intensity levels can be captured and recorded for at least three different wavelengths, such as a white wavelength, a blue wavelength, and a near-infrared wavelength, during at least three time periods.

[0015] The one or more processors may be configured to display the combined scan information and the 3D model on a display unit of the system.

[0016] The one or more processors may be configured to generate or update the 3D model using the visible light information and determine the combined scan information including enhanced internal structure in the form of enhanced contrast between internal structure (e.g., a caries lesion) and tooth structure. The tooth structure is primarily provided by the visible light information, while the internal structure is primarily provided by the internal structure information. Utilizing the visible light information for both the 3D model and the combined scan information facilitates mapping the combined scan information onto the 3D model or determining a location of the combined scan information on the 3D model.

[0017] In another example, the handheld intraoral scanning device first performs a scan to generate or update the 3D model, and then performs another scan thereafter to determine the combined scan information, which will result in a more complex way of aligning the position of the combined scan information on the 3D model compared to the present disclosure.

[0018] In another example, the intraoral scanning system can perform a scanning sequence in which visible light information is received during a first time period and used only to generate or update the 3D model; then, during a subsequent time period, newly received visible light information is used only to determine combined scan information. This example results in a lower scanning rate, but a 3D model of similar quality is obtained as if the visible light information received during the first time period is also used to determine the combined scan information.

[0019] The present disclosure allows for faster scan rates to provide both scan information and combined scan information for a 3D model because scan information associated with generating or updating the 3D model is also used to determine the combined scan information.

[0020] Compared to separate near-infrared and fluorescence information, or compared to enhanced fluorescence information with specular reflections removed, the combined scan information includes enhanced internal structure information. Because the contrast between internal structure and surface structure is higher with near-infrared information, the internal structure of the tooth is easier to identify in near-infrared information than in fluorescence information. Therefore, there is no interest in attempting to enhance internal structure information in fluorescence information. In the present disclosure, the combined scan information includes enhanced internal structure information. The enhanced internal structure information includes enhanced contrast between the internal structure and surface structure of the tooth. Therefore, dentists can more easily identify early caries at a stage where preventive measures may affect remineralization, thereby repairing damage caused by caries infection before more complex restorative measures are necessary. Furthermore, if fluorescence information is used for color subtraction, demineralization is always dark, so the IR signal is enhanced. If one uses white light images, early caries lesions appear bright (white spots), while older lesions appear dark. Therefore, this does not consistently enhance the IR signal as well as the fluorescence image.

[0021] I would also like to add that the structural similarity between Fluo and NIR images (which is not present in the visible image) allows for the subtraction of a nice common background, thus highlighting the features of interest.

[0022] (not by increasing signal, but by reducing background)

[0023] The one or more processors may be configured to determine fluorescence information of the dental arch based on the visible light information. The fluorescence information may include green fluorescence information and / or red fluorescence information. In this example, the projection unit may include multiple light sources configured to emit light ideal for determining surface information, fluorescence information, and internal structure information of the teeth in the dental arch.

[0024] The combined scan information may include differences between internal structure information and visible light information, or differences between internal structure information and fluorescence information. These differences result in enhanced internal structure information relative to the near-infrared image, fluorescence image, or enhanced fluorescence image. Furthermore, the differences between internal structure information and fluorescence information further enhance internal structure information compared to combined scan information that includes differences between internal structure information and surface information.

[0025] The one or more processors may be configured to determine a first difference between the internal structure information and the green fluorescence information and a second difference between the internal structure information and the red fluorescence information, and wherein the one or more processors may be configured to determine the combined scan information by summing the first difference and the second difference. Summing the two combined scan information has been shown to be ideal for enhancing the internal structure information, particularly associated with caries lesions, so that it is more easily distinguishable from other structural information of the tooth.

[0026] The combined scan information may include the sum of internal structure information, green fluorescence information, and red fluorescence information, and relative to the previous example in which two combined scan information are added together, the dentin-enamel junction is more enhanced, making it easier to distinguish from other structural information of the tooth.

[0027] Combined scan information may include the difference between internal structure information and surface information, or vice versa. In this example, combined scan information is ideal for enhancing internal structure information associated with restorations. The order of internal structure information and surface information has been shown to be relevant for enhancing different types of restorations. For example, combined scan information comprising internal structure information minus surface information is ideal for enhancing internal structure information associated with a first type of restoration; whereas combined scan information comprising surface information minus internal structure information is ideal for enhancing internal structure information associated with a second type of restoration.

[0028] The one or more processors may be configured to determine the combined scan information such that the combination of the internal structure information and the visible light information is based on light intensities corresponding to the internal structure information and the visible light information from the image sensor unit. In another example, the one or more processors may be configured to determine the combined scan information such that the combination of the internal structure information and the visible light information means a merging of light intensities of the internal structure information and the visible light information, where each of the two images corresponds to the internal structure information and the visible light information, respectively. The merging of light intensities may mean addition, subtraction, or weighting of the light intensities.

[0029] The combination may correspond to a light intensity difference between the light intensity of the internal structure information and the light intensity of the visible light information, or vice versa, or a light intensity sum between the light intensity of the internal structure information and the light intensity of the visible light information.

[0030] The combination may include a light intensity difference between the light intensity of the internal structure information and the light intensity of the visible light information, wherein the intensity difference enhances the internal structure information. The combination may be applied to a 3D model or a 2D image including visible light information, such as white (light) information corresponding to surface information of a dental object.

[0031] The combination of internal structure information and visible light information does not imply adding, combining, or merging the two images for the purpose of simultaneously displaying or visualizing them. Furthermore, the combination of internal structure information and visible light information does not imply adding, combining, or merging the two images for the purpose of simultaneously displaying or visualizing them one above the other. The purpose of the combination is to enhance the internal structure information of the dental object / dental arch. Enhanced internal structure information means that the visibility of the internal structure information is significantly improved compared to internal structure information identified through infrared images alone.

[0032] The light intensity may correspond to the light intensity of one or more pixels of the image unit, and in the combined scan information, the pixel area of ​​the image sensor unit configured to capture the information corresponds to the captured visible light information and internal light information. The combined scan information may be in the form of a bitmap suitable for overlaying on a 2D image or 3D model or a 2D image (e.g., a 256x256 image), wherein each pixel may be generated by subtracting and / or adding two or more different 2D images (i.e., light information captured by different wavelengths).

[0033] The visible light information may be dominated by surface information, and subtracting the visible light information from the internal structure information will produce combined scan information in which the surface information is less in the internal structure information. The one or more processors may be configured to vary the influence of the visible light information on the internal structure information by applying a weighting coefficient to each information, wherein a lower weighting coefficient for the visible light information will correspond to less surface information being removed from the internal structure information, or vice versa, a greater weighting for the visible light information will result in more surface information being removed from the internal structure information.

[0034] Internal structure information and visible light information can be weighted in the combined scan information, with the internal structure information weighted by a first weighting coefficient and the visible light information weighted by a second weighting coefficient. When determining the combined scan information, the contributions of the visible light information and the internal structure information may differ. The relative contributions of each type of information can be controlled by the weighting coefficients. The visible light information can include both surface information and fluorescence information. In this example, the relative contribution of the surface information can be weighted by a first primary weighting coefficient, while the relative contribution of the fluorescence information can be weighted by a first secondary weighting coefficient.

[0035] The one or more processors may be configured to vary the first and second weighting factors, wherein the variation may correspond to a change in brightness, contrast, and / or transparency of the internal structure information and the visible light information, respectively. Different levels of weighting factors may be desirable for different dental conditions to be enhanced, e.g., enhancing internal structure and / or enhancing texture information. For example, if the combined scan information includes a difference between internal structure information and visible light information, and the weighting factor for the visible light information is less than the weighting factor for the internal structure information, the combined scan information may be desirable for detecting restorations, while a larger weighting factor for the visible light information may produce combined scan information that is desirable for detecting caries. Thus, the one or more processors may be configured to automatically determine the level of weighting factors based on the dental condition to be enhanced. The settings for the weighting factors for different dental conditions may be pre-programmed into the memory of the intraoral scanning system, or the settings for the weighting factors may be controlled or set by a user via user input to the system.

[0036] The combined scan information is ideal for enhancing internal structures, such as the dentin-enamel connection, demineralization, cracks, caries lesions, voids, plaque, and restorations. The intraoral scanning system may be configured to determine different combined scan information based on two or more different wavelengths emitted by the projection unit. The one or more processors may be configured to determine a plurality of combined scan information, including the combined scan information and second combined scan information, wherein the combined scan information is different from the second combined scan information. The second combined scan information may be suitable for enhancing a different type of dental condition than the combined scan information, or the second combined scan information may correspond to the same tooth as the combined scan information but captured at a different angle between the dental arch and the image sensor unit.

[0037] Each of the plurality of combined scan information may include a different enhanced internal structure, and the one or more processors may be configured to tag each of the plurality of combined scan information. The tag indicates the specific enhanced internal structure of the tagged combined scan information in the plurality of combined scan information. The one or more processors may then be configured to select one or more combined scan information associated with a specific enhanced internal structure. The one or more processors may receive user input corresponding to the specific enhanced internal structure, and the one or more processors may then be configured to display the one or more combined scan information associated with the specific enhanced internal structure.

[0038] The enhanced internal structure may correspond to a dental condition of a tooth in the patient's dental arch, wherein the dental condition corresponds to cracks, demineralization, caries, dentin-enamel junction, voids, plaque, and restorations. For example, a combined scan including enhanced caries information may be labeled differently than a second combined scan including enhanced restoration information, and so on.

[0039] The projection unit may be configured to emit light having the different wavelengths during consecutive time periods or during time periods in which each time period is limited to one of the different wavelengths.

[0040] The projection unit may include one or more first light sources and at least one or more second light sources, wherein the one or more first light sources are configured to emit light in a near-infrared wavelength spectrum during a first set of time periods, and the one or more second light sources are configured to emit light in a visible wavelength spectrum during a second set of time periods. The handheld intraoral scanning device may be configured to switch between the one or more first light sources and the at least one or more second light sources. The switching may include turning the light sources on and off.

[0041] The light source can be one or a combination of the following:

[0042] Light-emitting diodes (LEDs),

[0043] Broadband light-emitting diodes, and

[0044] ·Continuous broadband light emitting diodes.

[0045] The visible light information may include information corresponding to reflection from the tooth surface caused by the first visible wavelength and captured by the image sensor unit, or the visible light information may include information corresponding to fluorescence information emitted by the tooth surface caused by exposure to the second visible wavelength and captured by the image sensor unit.

[0046] The projection unit may include at least one or more third light sources, wherein the one or more second light sources may be configured to emit light at a first visible wavelength during a second set of time periods, and the one or more third light sources may be configured to emit light at a second visible wavelength during a third set of time periods. The first visible wavelength may be different from the second visible wavelength, and wherein the visible light information may include information corresponding to reflection caused by the first visible wavelength and captured by the image sensor, and wherein the visible light information may include information corresponding to fluorescence information caused by the second visible wavelength and captured by the image sensor unit.

[0047] The one or more processors may be configured to determine surface information provided by the reflection at a first visible wavelength, and the combined scan information may include a combination of internal structure information and visible light information including the reflection at the first visible wavelength, and / or the combined scan information may include a combination of internal structure information and visible light information including fluorescence information at a second visible wavelength. Thus, the one or more processors may be configured to determine a plurality of combined scan information including sums and / or differences between the internal structure information, the surface reflection, and / or the fluorescence information.

[0048] The near-infrared wavelength may be between 701 nanometers and 2500 nanometers, the first visible wavelength may be between 380 nanometers and 700 nanometers, the second visible wavelength may be between 100 nanometers and 500 nanometers, and the visible wavelength may be between 100 nanometers and 700 nanometers. In another example, the first visible wavelength may be a white wavelength (430 to 750 nanometers), and the second visible wavelength may be a blue wavelength (i.e., 380 nanometers to 420 nanometers).

[0049] The image sensor unit may include at least one image sensor configured to capture light in a range between 100 nm and 2500 nm. The image sensor unit may include a plurality of image sensors, wherein each of the plurality of image sensors is configured to capture light between 701 nm and 2500 nm, 100 nm and 500 nm, or 380 nm and 700 nm.

[0050] The NIR image sensor of the plurality of image sensors may be arranged away from other image sensors of the plurality of image sensors.

[0051] The light emitted by the projection unit can be guided by a probe of the handheld intraoral scanning device and pass through a window in the probe. The NIR image sensor can be arranged near the window, or above the window and inside the probe.

[0052] The projection unit can be configured to emit light of different near-infrared wavelengths so as to penetrate the dental arch, i.e., one or more teeth, at different depths so as to generate depth information of the enhanced internal structure. For example, it would be advantageous to know the depth of caries, restorations, cracks, etc. By determining a plurality of combined scan information, wherein each of the plurality of combined scan information is determined based on internal structure information having a different near-infrared wavelength, the one or more processors can be configured to determine the depth of the enhanced internal structure based on the plurality of combined scan information. For example, each combined scan information corresponds to the enhanced internal structure at a depth in the tooth corresponding to the near-infrared wavelength. The one or more processors are configured to determine the depth based on a depth relationship algorithm, which includes a relationship between depth and near-infrared wavelength in different types of teeth. The algorithm receives the near-infrared wavelength corresponding to the combined scan information and outputs the corresponding depth within the tooth.

[0053] The projection unit may be configured to emit light having different near-infrared wavelengths, and the image sensor unit may be configured to capture internal light information from at least the dental arch caused by the different near-infrared wavelengths. The one or more processors may then be configured to determine a plurality of internal structure information, wherein each of the plurality of internal structure information corresponds to a reflection caused by a near-infrared wavelength from among the different near-infrared wavelengths. The one or more processors may also be configured to determine a plurality of combined scan information, wherein each of the plurality of combined scan information is determined based on each of the plurality of internal structure information and the visible light information.

[0054] The one or more processors may be configured to determine depth information of an enhanced internal structure of one or more teeth of the dental arch, wherein the determined depth information is based on the plurality of combined scan information.

[0055] The maximum depth of the enhanced internal structure may not be determined based on the multiple combined scan information because the different near-infrared wavelengths do not include a precise wavelength that can penetrate the tooth and reach the maximum depth of the enhanced internal structure. In this example, the system may include a memory unit that includes a relationship between near-infrared wavelengths and depths (i.e., penetration depths) of different types of teeth, and wherein the one or more processors may be configured to determine the longest near-infrared wavelength among the different near-infrared wavelengths, wherein the enhanced internal structure is identified in one of the multiple combined scan information by the one or more processors. The one or more processors may be configured to determine the internal depth information of the enhanced internal structure based on the longest near-infrared wavelength and the stored relationship between the near-infrared wavelength and the tooth penetration depth. The internal depth information may then be an interpolation of the longest near-infrared wavelength and the stored relationship.

[0056] The different types of teeth may be incisors, canines, premolars, molars, and third molars.

[0057] In another example, the light emitted by the projection unit may be a coded structured light formed by a grid pattern, and light from (one or more) light sources passes through the grid pattern to form a coded structured light emitted to the dental arch. The one or more processors may be configured to apply a series of encoding and decoding algorithms to process the grid pattern. The reflection of the coded structured light may be captured by the image sensor unit, and the internal depth information may be determined based on triangulation between the point clouds of the coded structured light. The coded structured light may include (one or more) near-infrared wavelengths and / or visible wavelengths. The visible light information may include coded structured visible light. The internal light information may include coded structured near-infrared light.

[0058] The number of near-infrared wavelengths may be limited by the size of the handheld intraoral scanning device and the size of the light source, so it may be necessary to estimate sub-interior depth information within the tooth between the available near-infrared wavelengths of the projection unit, or deeper than the depth allowed by these available near-infrared wavelengths. Therefore, a trained neural network may be required to perform this sub-interior depth information estimation. First, the one or more processors are configured to determine first and second depth information based on the available near-infrared wavelengths, and then determine the sub-interior depth information based on the trained neural network that receives the first and second depth information. The neural network is configured to determine the sub-interior depth information of the tooth by interpolating the received depth information and understanding the tooth type to which the received depth information corresponds. The neural network can be trained based on multiple combined scan information, where the combined scan information is determined based on different near-infrared wavelengths and the relationship between the near-infrared wavelengths and corresponding penetration depths within different tooth types of one or more patients. In another example, the neural network is trained based on X-ray scan information or OCT scan information from one or more patients. The neural network can include one or more of the following topologies: a convolutional neural network (CNN), a three-ring model, a persistent homology method, and algebraic topology.

[0059] To improve the quality of the internal light information, it may be advantageous to capture light from different angles between the dental arch and the image sensor unit and then combine the light from the different angles into a single light information. This combination may be an average or weighted average of the light from the different angles. The internal structure information may be determined based on multiple captured internal light information, wherein the multiple captured internal light information may be captured by the image sensor unit at different angles between the dental arch and the image sensor unit. The internal structure information may be determined based on an average or weighted average of the multiple captured internal light information.

[0060] The one or more processors may be configured to determine surface information and / or fluorescence information based on a plurality of captured visible light information, wherein the plurality of captured visible light information may be captured by the image sensor unit at different angles between the dental arch and the image sensor unit.

[0061] The determined surface information and / or fluorescence information may be based on an average or weighted average of the plurality of captured visible light information.

[0062] The emitted light may penetrate a window in the handheld intraoral scanning device, and the system may have a longitudinal axis perpendicular to a surface of the window. The emitted light may penetrate the window along the longitudinal axis, and different angles between the dental arch surface and the longitudinal axis may be determined. The longitudinal axis may intersect the dental arch surface, and different angles may be formed between the surface and the longitudinal axis.

[0063] The combined scan information typically includes an enhanced internal structure, which can be displayed in combination with a 2D image (e.g., a white light image), an NIR image, or a fluorescent image. The display can be an overlay on the 2D image. The enhanced internal structure can be displayed in combination with a 3D model of the dental arch. The display can be an overlay on the 3D model. If a user of the system wishes to display different enhanced internal structures on one 2D image or 3D model, it would be advantageous to determine mixed scan information that includes a combination of the multiple combined scan information, wherein at least two of the multiple combined scan information include different enhanced internal structures. The mixed scan information may include multiple channels, wherein each of the multiple channels corresponds to each of the multiple combined scan information.

[0064] When displaying the combined scan information, it may be advantageous to assign different colors to different enhanced internal structures so that users of the system can more easily distinguish between the different enhanced internal structures. The one or more processors may assign a different color to each of the multiple channels. To further enhance the ability to distinguish between different enhanced internal structures, it may be advantageous if the one or more processors are configured to weight each of the multiple channels differently or similarly using a channel weighting coefficient. The channel weighting coefficient determines the contribution of the combined scan information to the combined scan information. Furthermore, adjusting the channel weighting coefficient for each of the multiple channels will result in changes in the brightness, contrast, and / or transparency of the combined scan information.

[0065] The combined scan information can be in the form of a bitmap suitable for overlaying on a 2D image, 3D model, or 2D image, such as a 256x256 image, where each pixel can be generated by subtracting and / or adding two or more different 2D images (i.e., light information captured by different wavelengths). Hybrid scan information can also be represented as a bitmap or 2D image, where each pixel can represent multiple channels of information.

[0066] The multiple channels may include a first channel corresponding to background information, which may include first combined scan information from the multiple combined scan information; and a second channel corresponding to first stacked information, which may include second combined scan information from the multiple combined scan information. The first stacked information may be aligned with and stacked on the background information. For example, the enhanced internal structure of the background information may be grayscale color information, while the first stacked information may be red information that includes a different type of enhanced internal structure than the background information.

[0067] Two or more of the plurality of combined scan information may include similar types of enhanced structural information for the same or multiple teeth in the dental arch. In this example, it may be beneficial to combine the two or more combined scan information into one of the multiple channels of the mixed scan information. The multiple channels may include a single combined scan information from the plurality of combined scan information or a combination of multiple combined scan information from the plurality of combined scan information. The combination of multiple combined scan information may include, for example, the sum of the first and second combined scan information from the plurality of combined scan information.

[0068] The combined scan information may include enhanced internal structure information configured for display on a display unit of the system. The combined scan information may be further processed by one or more processors to display the combined scan information or the plurality of combined scan information. The combined scan information may include additional scan information in addition to the enhanced internal structure information. This additional scan information may be used to align the combined scan information with a background 2D image or 3D model, or with second combined scan information, for display. The one or more processors may be configured to display the combined scan information on a display unit of the intraoral scanning system.

[0069] The additional scan information may include scan information of other portions of the one or more teeth in the dental arch that are not relevant to the augmented internal structure, and may also include information on the gums, bone, and other portions of the dental arch. The additional scan information may be structural information of the teeth, gums, or any anatomical structure in the dental arch.

[0070] A dental arch is a curved structure that includes teeth, gums, and bone. A dental arch can be maxillary, mandibular, or bimaxillary.

[0071] The one or more processors may be configured to determine enhanced internal structure and / or enhanced texture information based on the combined scan information. The enhanced texture information may include enamel, dentin, dentin-enamel junction, fetal, root apex, bone, periodontal ligament, and / or gingiva.

[0072] The one or more processors may be configured to apply enhanced internal structure and / or enhanced texture information to a 3D model or a 2D image of one or more teeth of a dental arch. Applying the enhanced internal structure and / or enhanced texture information to the 3D model or the 2D image may be provided by identifying one or more reference features in the combined scan information including the enhanced internal structure and / or enhanced texture information, and identifying one or more other reference features on the 3D model or the 2D image, and aligning the one or more reference features with the one or more other reference features. The identification and alignment are provided by the one or more processors.

[0073] Within a time frame, the projection unit may be configured to emit visible light pulses comprising visible wavelengths and near-infrared light pulses comprising near-infrared wavelengths, with a dead pulse time possibly occurring between each pulse. The dead pulse time represents a period during which no pulses are emitted. During the time frame, one or more visible light pulses may be emitted by the projection unit, and then, after the dead pulse time, one or more near-infrared light pulses may be emitted. The captured visible light information and the internal light information resulting from the light pulses emitted during the time frame all correspond to the same region of the dental arch. In this example, alignment of the multiple combined scan information is not required, or sparse alignment may be required. If the user of the handheld intraoral scanning device moves the device too quickly, causing the captured light information within the time frame to not correspond to the same region of the dental arch, the one or more processors may be configured to provide a warning. During a time frame, during certain scanning modes, such as scanning mode or diagnostic mode, the visible light information may have a higher resolution than the internal light information.

[0074] In another example, each of the plurality of combined scan information may include a reference structure for aligning the plurality of combined scan information in the hybrid scan information. The one or more processors may be configured to perform alignment of the plurality of combined scan information.

[0075] The dead pulse time may be less than 0.1 millisecond, less than 0.05 millisecond, or less than 0.03 millisecond.

[0076] The one or more processors may be configured to determine a 3D model in real time by stitching together a plurality of surface information, wherein each of the plurality of surface information is determined based on a plurality of visible light information captured during a same time frame. Combined scan information may be determined based on the interior light information and the visible light information captured during the same time frame, and the one or more processors may be configured to display the combined scan information on a 2D image determined based on the visible light information, the visible light information also being used to determine the combined scan information.

[0077] The one or more processors may be configured to determine enhanced internal structure and / or enhanced texture information based on the combined scan information. The enhanced internal structure and / or enhanced texture information may include location, shape, and size measurements of the dental condition. The one or more processors may be configured to apply the enhanced internal structure and / or enhanced texture information to a portion of the 3D model. The portion of the 3D model includes surface information determined based on the visible light information and captured during a same time frame as the visible light information and the internal light information used to determine the combined scan information.

[0078] The one or more processors may be configured to apply enhanced internal structure and / or enhanced texture information to the 2D surface image including surface information. The surface information may be determined based on visible light information captured during a same time frame in which the visible light information and the internal light information are captured and used to determine the combined scan information.

[0079] The one or more processors may be configured to apply the enhanced internal structure and / or enhanced texture information to the 3D model or the 2D surface image of one or more teeth of the dental arch.

[0080] The determined depth information of the corresponding enhanced internal structure and / or enhanced texture information can be displayed on a display unit. For example, a marker can be displayed on the display unit, and the one or more processors are configured to move the marker based on user input via a user input device of the system. When the marker is placed on a portion of the enhanced internal structure and / or enhanced texture information on the 3D model or 2D surface image, the interior depth information can be displayed next to the marker, or next to the enhanced internal structure and / or enhanced texture information. The marker provides an intuitive way to display the interior depth information.

[0081] The one or more processors may be configured to display interior depth information and / or enhanced texture information corresponding to the enhanced interior structure on a display unit of the system. The one or more processors may be configured to display the interior depth information on the display unit on a 3D model, on a 2D surface image, next to the 3D model, or next to a 2D surface. Different methods...

[0082] The marker may be a pointer, a circle with an opening, a cursor, a square with an opening, or the like.

[0083] The one or more processors may be configured to display a three-dimensional (3D) model of a dental arch on a display unit of the intraoral scanning system and to display a marker on a portion of the 3D model of the dental arch on the display unit. The one or more processors may be configured to change a relative position between the marker and the 3D model of the dental arch based on input from a user input device of the intraoral scanning system. The one or more processors may be configured to identify, from both the 3D model of the dental arch and the plurality of combined scan information, combined scan information in the plurality of combined scan information that approximates a relative angle and position of the marker relative to the 3D model of the dental arch, wherein each of the plurality of combined scan information includes internal light information and visible light information captured at an angle and position. The one or more processors may be configured to display the identified combined scan information, the identified combined scan information being determined for an angle and position that approximates the angle and position of the marker relative to the 3D model of the dental arch. In this example, the one or more processors are configured to select the fluorescence information and the internal structure information by comparing the angle and position of the captured visible light information and the internal light information corresponding to the fluorescence information and the internal structure information with the approximate angle and position between the marker and the 3D model. Again, tags provide an intuitive way to identify and display related combined scan information.

[0084] The one or more processors may be configured to display a three-dimensional (3D) model of a dental arch on a display unit of the intraoral scanning system and to display a marker (a view marker, a cursor) on a portion of the 3D model of the dental arch on the display unit of the system. Furthermore, the one or more processors may be configured to continuously identify, from both the 3D model of the dental arch and a plurality of combined scan information, a group of combined scan information from the plurality of combined scan information, as a user changes a relative position between the marker and the 3D model of the patient's dental arch based on user input, wherein the plurality of combined scan information includes a group of combined scan information determined for internal light information and visible light information obtained at the same angle and position relative to the dental arch, the group of combined scan information being determined at an angle and position similar to the angle and position of the marker relative to the displayed 3D model of the dental arch. Furthermore, the one or more processors may be configured to display, on the display unit, at least one of the group of combined scan information corresponding to an angle and position similar to the angle and position of the marker relative to the displayed 3D model of the dental arch. The group of combined scan information may correspond to the same tooth or region of the dental arch, wherein each of the grouped combined scan information may include a different enhanced internal structure and / or enhanced texture structure.

[0085] The one or more processors may be configured to receive one or more of the plurality of combined scan information including the internal structure based on user input, associate the one or more of the plurality of combined scan information with the 3D model, associate the location of the one or more of the plurality of combined scan information with a corresponding location in the 3D model, and display the 3D model on a display unit of the system, wherein the cross-section includes the one or more of the plurality of combined scan information and displays the plurality of internal structures including the internal structure. The one or more of the plurality of combined scan information may be displayed on the 3D model. The cross-section through the 3D model may be determined by the location of the marker or the location of the decisive dental condition determined based on the user input.

[0086] The one or more processors may be configured to display a label selector in a user interface of the intraoral scanning system, the label selector configured to select one or more of the plurality of labeled combined scans based on user input. The label selector may correspond to a push-to-release button or checkbox on a touch screen, a keyboard, or any other type of selection device that allows the user to select different labels. Labels correspond to dental conditions, such as caries, restorations, cracks, enamel-enamel junctions, and other types of internal or textural structures. The one or more processors may be configured to select one or more regions of interest on the 3D model based on the user input, each region of interest corresponding to the location of one or more teeth in a dental arch on the 3D model; select one or more combined scans based on the one or more selected regions of interest on the 3D model and the one or more selected labels; and display the one or more combined scans on a display unit of the intraoral scanning system. The user can use the label selector to select those combined scans associated with the selected label, i.e., the selected dental condition enhanced in the combined scans. These selected combined scans may also be associated with one or more regions of interest on the 3D model, and these one or more regions of interest may be selected by marking them on the 3D model.

[0087] The display of the combined scan information can include combining the combined scan information with surface information or fluorescence information. One example can be displaying enhanced internal structure and / or enhanced texture information of the combined scan information over the surface information or fluorescence information. The surface information or fluorescence information can be a 3D model or a 2D surface image. The combined scan information, surface information, or fluorescence information can correspond to the same or multiple teeth in a dental arch. The surface information or fluorescence information associated with the surfaces of one or more teeth in the dental arch can be colored with one or more colors, while the combined scan information can be colored with one or more colors that are unrelated to the one or more colors of the surface. The one or more processors can be configured to select the one or more colors of the surface and combined scan information based on user preferences or based on color machine learning outputs of a color machine learning unit of the system, the color machine learning unit being trained based on a training dataset comprising user preferences of multiple users of the system. A user of the system may be color blind or have a preference for color combinations, in which case it would be beneficial for the user to be able to select one or more colors. The color machine learning unit can be trained to select the optimal color combination based on the shape and type of enhanced internal structure and / or enhanced texture information. The color machine learning unit may be trained by the color preferences of other users of the system with respect to enhancing the shape and type of internal structures and / or enhancing texture information.

[0088] The hybrid scan information can be configured to be displayed on a display unit of the intraoral scanning system. The displayed hybrid scan information can include a combination of the hybrid scan information and surface information or fluorescence information. One example can be displaying enhanced internal structure and / or enhanced texture information of the multiple combined scan information of the hybrid scan information over the surface information or fluorescence information. The surface information or fluorescence information can be a 3D model or a 2D surface image. One or more teeth in a dental arch may include different types of dental conditions or multiple identical dental conditions, and in such cases, the user may wish to display these dental conditions on a single 2D image or 3D model. The one or more processors can be configured to select the multiple combined scan information of the hybrid scan information to be displayed based on user input. The multiple combined scan information may include different types of dental conditions or multiple identical dental conditions, i.e., enhanced internal structure and / or enhanced texture information. The one or more processors can be configured to add or remove one or more combined scan information from the multiple combined scan information of the hybrid scan information based on the user input. The displayed hybrid scan information can include one or more colors representing the surface information or fluorescence information, and the hybrid scan information can be represented by one or more colors independent of the one or more colors representing the surface information or fluorescence information. The one or more processors may be configured to change the coloring of the one or more colors of the mixed scan information and the one or more colors of the surface information or the fluorescence information based on user input.

[0089] The one or more processors may be configured to display a three-dimensional (3D) model of a dental arch on a display unit of the intraoral scanning system and to display a marker on a portion of the 3D model of the dental arch on the display unit. The one or more processors may be configured to change a relative position between the marker and the 3D model of the dental arch based on input from a user input device of the intraoral scanning system, and to identify two or more combined scan information from both the 3D model of the dental arch and the plurality of combined scan information, wherein each of the plurality of combined scan information includes internal light information and visible light information captured at an angle and position that approximates the relative angle and position of the marker relative to the 3D model of the dental arch. Furthermore, the one or more processors may be configured to display mixed scan information including the identified two or more combined scan information, wherein the internal light information and visible light information of the selected two or more combined scan information correspond to angles and positions that approximate the angles and positions of the marker relative to the 3D model of the dental arch.

[0090] The one or more processors may be configured to display the composite scan information including the plurality of combined scan information on a display unit of the system, and to display a slider (a view mark, a cursor) adjacent to the composite scan information displayed on the display unit. Furthermore, the one or more processors may be configured to change a position of the slider based on user input from a user input device of the intraoral scanning system, and to add or remove the composite scan information from the composite scan information based on the position of the slider. The slider provides an intuitive and convenient method of adding or removing one or more combined scan information from the composite scan information based on the position of the slider.

[0091] The handheld intraoral scanning device can be configured to emit light of different wavelengths during different time periods. During one time period, light of a near-infrared wavelength can be emitted; and during one or more consecutive time periods, the emitted light can include visible wavelengths. The different time periods can be confined to a time frame. During the time frame, the projection unit can be configured to emit visible light pulses including visible wavelengths and near-infrared light pulses including near-infrared wavelengths, with dead pulse times occurring between the pulses. The dead pulse times represent periods of time during which no pulses are transmitted. During the time frame, one or more visible light pulses can be emitted by the projection unit, and then, after the dead pulse times, one or more near-infrared light pulses can be emitted by the projection unit. The captured visible light information and the internal light information resulting from the light pulses emitted during the time frame all correspond to the same region of the dental arch. The one or more processors are configured to provide a warning if a user of the handheld intraoral scanning device moves the device too quickly, causing the light information captured within the time frame to no longer correspond to the same region of the dental arch.

[0092] The projection unit may include one or more first light sources and at least one or more second light sources, wherein the one or more first light sources may be configured to emit light at a near-infrared wavelength during a first set of time periods, and the one or more second light sources may be configured to emit light at a visible wavelength during a second set of time periods. The first and second sets of time periods may be arranged accordingly within a time frame. The time frame may include time periods of a first repetition rate for the first set of time periods and time periods of a second repetition rate for the second set of time periods. The time frame may include time periods of a third set of time periods at a third repetition rate. The third set may correspond to one or more third light sources of the projection unit. The first, second, and / or third repetition rates may be determined by the one or more processors based on a scanning mode, wherein the scanning mode is determined based on user input. The scanning mode may be one of the following: a first diagnostic mode, in which the first repetition rate is greater than or equal to the second repetition rate; a second diagnostic mode, in which the first and third repetition rates are greater than or equal to the second repetition rate; and a first surface scanning mode, in which the first repetition rate is less than the second repetition rate. By adapting the repetition rate to a specific scanning mode, if the captured visible light information and internal light information are transmitted directly to an external device, this can provide for optimized utilization of wireless communication bandwidth for the scanning mode; and / or provide for optimization of power consumption of the handheld intraoral scanning device, since only light relevant to the specific scanning mode is emitted and captured. Furthermore, adapting the repetition rate provides for optimized utilization of the processing power of the one or more processors.

[0093] The one or more processors may be configured to switch between different scanning modes during a dental arch scanning process based on user input. For example, if a user suddenly decides to perform a diagnostic scan of a portion of a dental arch during a surface scanning process, switching between different scanning modes during the scanning process may be preferable.

[0094] The system may include a wireless communication interface between the handheld intraoral scanning device and one of the one or more processors or a group of the one or more processors, wherein the visible light information may be wirelessly transmitted at a first data rate and the internal light information may be wirelessly transmitted at a second data rate. The handheld intraoral scanning device may include a wireless transceiver configured to send and / or receive data, power, and / or information. The handheld intraoral scanning device may include one of the one or more processors, wherein the one processor may be configured to determine combined scan information and wirelessly transmit the combined scan information to another of the one or more processors. The one processor may be configured to generate or update a three-dimensional model and wirelessly transmit the three-dimensional model to the other processor.

[0095] The one or more processors may be configured to vary the first data rate and / or the second data rate based on the scanning mode. The first data rate may be different from or the same as the second data rate. By adjusting the data rate of the wireless communication, the one or more processors are configured to optimize utilization of the wireless communication bandwidth for different scanning modes. The visible light information and the internal light information may be wirelessly transmitted at the same data rate or at different data rates.

[0096] The wireless transmission of the visible light information and the internal light information may be transmitted in groups, wherein the group includes the visible light information and the corresponding internal light information. Thus, the one or more processors are configured to align the combined scan information or the hybrid scan information with a specific region of the 3D model or a specific 2D surface image of the dental arch.

[0097] The wireless transmission of the visible light information may include a first identifier, and the wireless transmission of the internal light information may include a second identifier, wherein the combined scan information includes a combination of internal structure information determined by the internal light information including the second identifier and visible light information including the first identifier, and wherein the first identifier matches the second identifier. Thus, the one or more processors are configured to determine the combined scan information based on information associated with the same region of the dental arch. Furthermore, the one or more processors may then align the combined scan information or the hybrid scan information with a specific region of the 3D model or a specific 2D surface image of the dental arch based on the identifier.

[0098] The visible light information and the internal light information can be asynchronously and wirelessly transmitted to a processor or group of processors in the one or more processors. This asynchronous wireless transmission is relevant when it is not necessary to display the combined scan information in real time while simultaneously displaying the 3D model. Thus, regardless of the number of different wavelengths emitted by the projection unit, the handheld intraoral scanning device can maintain a normal movement speed and maintain the real-time display of the 3D model while scanning. The normal movement speed corresponds to a surface scanning mode, which includes generating and / or updating a 3D model and does not require generating combined scan information.

[0099] The visible light information and the internal light information can be synchronously wirelessly transmitted to one or a group of one or more processors. Synchronous wireless transmission is meaningful when it is necessary to display the combined scan information in real time while displaying the 3D model in real time.

[0100] Real-time display means that the 3D model and / or combined scan information is displayed immediately while scanning is being performed using the handheld intraoral scanning device. Immediate display includes that on the receiving side of the information to be displayed, the delay is at most imperceptible.

[0101] The one or more processors may be configured to select one or more modulation schemes for modulating visible light information and / or internal light information transmitted over the wireless network of the intraoral scanning system. The one or more processors may be configured to select one or more modulation schemes based on the scanning mode or the type of information transmitted over the wireless network. Thus, the one or more processors can optimize the modulation of the wirelessly transmitted information. Using the optimal modulation will ensure an appropriate balance between computing power, bandwidth of wireless communication, and real-time perceptibility of updating / generating the 3D model and / or combined scan information. The one or more modulation schemes may include the following modulation schemes:

[0102] MOK (M-ary Orthogonal Keying),

[0103] ACM (Automatic Coding and Modulation scheme),

[0104] MBOK (M-ary Biorthogonal Keying),

[0105] CCK (Complementary Code Keying),

[0106] CCSK (Cyclic Code Shift Keying),

[0107] PSK (Phase Shift Keying),

[0108] PPM (Pulse Position Modulation),

[0109] QAM (Quadrature Amplitude Modulation),

[0110] OCDM (Orthogonal Frequency Division Multiplexing) and

[0111] OFDM (Orthogonal Frequency Division Multiplexing).

[0112] The system may include a user interface configured to receive user input.

[0113] According to these aspects, an intraoral scanning system is disclosed. The intraoral scanning system may be configured to provide combined scan information including enhanced enamel demineralization information and / or enhanced dentin-enamel junction (DEJ) location information that may be associated with caries lesions, i.e., enhanced internal structure. The system may include a handheld intraoral scanning device, the intraoral scanning device including a projection unit configured to emit different wavelengths of light onto at least a dental arch during respective time periods, wherein the different wavelengths include near infrared wavelengths, blue wavelengths, and white wavelengths. Different types of tooth anatomy scatter and absorb infrared radiation differently. The scattering properties of enamel and dentin in the near infrared wavelength range make it possible to image the internal structure of a tooth.

[0114] Furthermore, caries and demineralization scatter NIR light and appear as darker or brighter areas when imaged, depending on the type of detection (transillumination and reflection, respectively). Furthermore, when teeth are exposed to light within the soft UV to blue light spectrum, the photons may excite the dental material and cause a fluorescence reaction, i.e. visible light information including fluorescence information. Healthy tooth material emits a green fluorescence signal when exposed to blue light (e.g. 405 nm), while bacteria and their metabolites may emit a red fluorescence signal, i.e. visible light information including fluorescence information. The latter can be observed, for example, when assessing caries lesions and old dental plaque in the presence of bacteria and their metabolites. By filtering the excitation wavelength from the light exposing the image sensor unit, the red and green fluorescence signals are captured.

[0115] The projection unit may further include an image sensor unit configured to capture visible light and internal light information from at least the dental arch caused by the light emitted by the projection unit. The system may further include one or more processors operably connected to the image sensor unit. The one or more processors may be configured to receive visible light information associated with the projected white wavelength and / or blue wavelength, and internal light information associated with the near-infrared wavelength. The one or more processors may also be configured to determine fluorescence information of the dental arch from the visible light information, determine internal structure information of the dental arch from the internal light information, and determine combined scan information comprising a combination of the internal structure information and the fluorescence information.

[0116] Visible light information and internal light information relate to specific wavelengths and can be reflected or emitted from the outer surface of the tooth and / or from the inner surface of the tooth (fluorescence information), wherein the inner surface is understood to be inside the tooth and is then captured by the image sensor unit.

[0117] It has been shown that generating combined scan information by subtracting and / or adding information from fluorescence information and internal structure information enhances enamel demineralization (caries lesion) information and / or enhances DEJ information. For example, the combined scan information may include the sum of a first difference between the internal structure information and the red fluorescence information and a second difference between the internal structure information and the green fluorescence information. The combined scan information may be superimposed on a 3D model or a 2D surface image, and the color representing the combined scan information should contrast strongly with the color used for the 3D model and the 2D surface image to further enhance the visibility of the enhanced caries and / or enhanced DEJ information. For example, the color of the combined scan information may be red. In addition, the brightness and / or contrast of the first difference and the second difference may be reduced or increased to improve the enhancement effect. The one or more processors may apply a reduction / increase in brightness / contrast by applying weighting coefficients to the internal structure information, the green fluorescence information, and the red fluorescence information.

[0118] Fluorescence information determined based on visible light information, wherein the visible light information includes blue wavelengths, and the fluorescence information includes green fluorescence information and / or at least red fluorescence information, wherein the green and red fluorescence information are light emitted from the dental arch that absorbs the visible light information (i.e., blue wavelengths).

[0119] The combined scanning information may include a difference calculation between the internal structure information and the fluorescence information. In this example, the combined scanning information results in enhanced enamel demineralization (proximal caries) information. The combined scanning information may alternatively include the sum of the internal structure information and the fluorescence information. In this example, the combined scanning information includes enhanced DEJ information. In conventional NIR images, the DEJ is also clearly visible, however, the enamel thickness along the edge of the tooth combined with the scattering makes the outer edge of the enamel less transparent, thereby forming a band-like transparent structure along the outer contour of the tooth. This band-like structure also appears in the fluorescence image, especially in the green fluorescence information where the signal is the strongest. This similarity in the band-like structure between the internal structure information and the fluorescence information is very useful in identifying caries lesions by difference imaging.

[0120] The one or more processors may be configured to determine a first difference between the internal structure information and the green fluorescence information, and a second difference between the internal structure information and the red fluorescence information, wherein the combined scan information includes the sum of the first and second differences. In this example, the enhanced enamel demineralization (proximal caries) information in the combined scan information is further enhanced compared to examples in which the combined scan information includes the difference between the internal structure information and only the red or green fluorescence information. This effect can be understood as follows. The internal structure of the tooth, as seen from the occlusal surface, is partially visible in the near-infrared. The thickness of the enamel when viewed from the occlusal surface along the edge of the tooth, combined with scattering, makes the outer edge of the enamel appear less transparent, thereby forming a band-like transparent structure along the outer contour of the tooth. Because most of the fluorescence signal comes from the dentin and less from the enamel, this band-like structure may also partially appear in the fluorescence image. This similarity in the band-like structure helps highlight proximal caries lesions when using differential imaging between NIR and fluorescence images. The red and green fluorescence signals appear differently from different areas of the tooth surface, but proximal caries lesions appear the same when using NIR-Fluo subtraction. This means that when considering the sum of [NIR-Fluo(R)] and [NIR-Fluo(G)], other structural differences are averaged out (appearing less pronounced), while the proximal caries lesion remains clear and clearly visible.

[0121] The combined scan information may include the sum of internal structure information, green fluorescence information, and red fluorescence information, and in this example, the enhanced DEJ information is further enhanced compared to simply adding the internal structure information to one of the fluorescence information (i.e., green or red fluorescence information). Dentin can absorb blue wavelengths and emit green and red fluorescence information, while enamel is considered a transparent material that generally does not provide any fluorescence information. For example, teeth may have demineralized surfaces, which can lead to increased reflection of, for example, blue wavelengths, resulting in less light absorption by the dentin. The proposed combined scan information overcomes this problem.

[0122] According to multiple aspects, an intraoral scanning system is disclosed. The intraoral scanning system can be configured to provide combined scan information including enhanced restoration information. The system can include a handheld intraoral scanning device, the device including: a projection unit configured to emit light at a near-infrared wavelength and a white wavelength onto at least a dental arch; and an image sensor unit configured to capture visible light information and internal light information from at least the dental arch caused by the light emitted by the projection unit. The system can also include one or more processors operably connected to the image sensor unit. The one or more processors can be configured to receive the visible light information and the internal light information, and determine surface information in real time from the visible light information so as to generate or update a three-dimensional (3D) model of the dental arch using the surface information. The one or more processors can also be configured to determine internal structure information of the dental arch from the internal light information, and determine combined scan information including a combination of the internal structure information and the surface information.

[0123] Restoration information may relate to fillings, inlays, onlays, crowns, and / or sealants.

[0124] The combined scan information includes enhanced restoration information, such as shape, size, position, material and type. Different materials may have different scattering and transmission properties in different spectral regions, even if they appear similar in one spectral region (e.g., the visible region). One material may be opaque in both the visible and NIR spectral regions, while another material may be opaque in the visible (region) and translucent in the NIR. It has been shown that a component comprising a difference between internal structure and surface information enhances one restoration type (e.g., a filling that may be related to the material it is composed of, such as amalgam, gold, metal, etc.), while a difference between surface information and internal structure enhances another restoration type (plastic, resin, ceramic, etc.). Therefore, by determining a hybrid scan information comprising two combined scan information, each associated with a different type of restoration, different types of restorations can be displayed on a single 2D surface image or 3D model.

[0125] The one or more processors may be configured to determine a first restoration type based on combined scan information including a difference between internal structure information and surface information, and to determine a second restoration type based on combined scan information including a difference between surface information and internal structure information. Being able to distinguish between different types of restorations is an advantage because this information is typically included in a patient's dental record, but in this example, this information can be automatically provided on the 3D model or dental record during or after the scanning process.

[0126] The one or more processors may be configured to determine a plurality of combined scan information, including at least: combined scan information including a difference between the internal structure information and the surface information; and second combined scan information including a difference between the surface information and the internal structure information. The plurality of combined scan information may be included in the hybrid scan information.

[0127] According to various aspects, a method for determining combined scan information is provided. The method includes:

[0128] emitting light having different wavelengths onto at least the dental arch during a plurality of time periods, wherein the different wavelengths include near infrared wavelengths and visible wavelengths,

[0129] capturing visible light information and internal light information from at least a dental arch caused by visible wavelengths and near-infrared wavelengths, respectively,

[0130] determining surface information in real time from the visible light information to generate or update a three-dimensional (3D) model of the dental arch using the surface information,

[0131] Determine the internal structure of the dental arch from the internal light information, and

[0132] Determining combined scan information including a combination of internal structure information and visible light information.

[0133] According to various aspects, a method for determining combined scan information is provided. The method includes:

[0134] emitting light at near infrared wavelengths, blue wavelengths, and white wavelengths onto at least the dental arch;

[0135] capturing visible light information and internal light information from at least the dental arch caused by the emitted light,

[0136] determining surface information in real time from the visible light information to generate or update a three-dimensional (3D) model of the dental arch using the surface information,

[0137] Determine the dental arch's fluorescence information from the visible light information associated with the emitted blue light wavelengths;

[0138] Determining internal structural information of the dental arch from this internal light information, and

[0139] Determining combined scan information comprising a combination of internal structure information and fluorescence information.

[0140] According to various aspects, a method for determining combined scan information is provided. The method includes:

[0141] emitting light having different wavelengths toward at least the dental arch during a plurality of time periods, wherein the different wavelengths include near infrared wavelengths and white wavelengths,

[0142] capturing visible light information and internal light information from at least a dental arch caused by visible wavelengths and near-infrared wavelengths, respectively,

[0143] determining surface information in real time from the visible light information to generate or update a three-dimensional (3D) model of the dental arch using the surface information,

[0144] Determine the internal structure of the dental arch from the internal light information, and

[0145] Determining combined scan information including a combination of internal structure information and visible light information. BRIEF DESCRIPTION OF THE DRAWINGS

[0146] Various aspects of the present disclosure may be better understood through the following detailed description in conjunction with the accompanying drawings. For the sake of clarity, these drawings are schematic and simplified, showing only some details to enhance understanding of the claims, while other details are omitted. Throughout the text, the same reference numerals are used to represent the same or corresponding parts. The individual features of each aspect may be combined with any or all features of the other aspects. These and other aspects, features and / or technical effects will be apparent and clarified by the following illustrations, in which:

[0147] Figure 1 An intraoral scanning system is shown;

[0148] Figures 2A to 2E Different examples of this system are shown;

[0149] Figures 3A to 3H Various examples of one or more processors are shown;

[0150] Figures 4A to 4H Different examples of combined scan information images depicting different dental conditions are shown;

[0151] Figures 5A to 5E Different examples of arrangements of projection units are shown;

[0152] 6A to 6D Different examples of arrangements comprising one or more light sources are shown;

[0153] Figure 7shows the arrangement of the tip of a handheld intraoral scanning device;

[0154] Figure 8A and 8B Different examples of optical arrangements are shown;

[0155] Figure 9A and 9B An example of a handheld intraoral scanning device is shown;

[0156] 10A to 10C An example of determining depth information is shown;

[0157] Figure 11 An example of how to improve the quality of combined scan information is shown;

[0158] Figure 12 An example of the one or more processors is shown;

[0159] 13A to 13C An example of mixed scan information is shown;

[0160] Figure 14A and 14B An example of a mixed scan information image is shown;

[0161] Figures 15A to 15C shows a graphical interface of a display unit;

[0162] Figure 16 shows a graphical interface of a display unit;

[0163] Figure 17 shows a graphical interface of a display unit;

[0164] Figure 18 shows a graphical interface of a display unit;

[0165] 19A to 19C shows a graphical interface of a display unit;

[0166] Figure 20 shows a graphical interface of a display unit;

[0167] Figure 21 shows a graphical interface of a display unit;

[0168] 22A to 22D A wireless communication interface is shown; and

[0169] Figure 23A and 23B The sequence of light emitted by the projection unit is shown. DETAILED DESCRIPTION

[0170] The detailed description set forth below in conjunction with the accompanying drawings is intended to describe various configurations. The detailed description includes specific details and is intended to provide a comprehensive understanding of the various concepts. However, it will be understood by those skilled in the art that these concepts can be practiced without these specific details. Several aspects of the devices, systems, media, programs, and methods are described by various blocks, functional units, modules, components, circuits, steps, processes, algorithms, etc. (collectively referred to as "elements"). Depending on the specific application, design limitations, or other reasons, these elements can be implemented using electronic hardware, computer programs, or any combination thereof.

[0171] The electronic hardware may include microprocessors, microcontrollers, digital signal processors (DSPs), field programmable gate arrays (FPGAs), programmable logic devices (PLDs), gated logic, discrete hardware circuits, and other appropriate hardware configured to perform the various functions described throughout this disclosure. A computer program should be broadly construed to mean instructions, instruction sets, code, code segments, program code, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, execution threads, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0172] The scanning for providing intraoral scan data may be performed by a dental scanning system, which may include an intraoral scanning device, such as the TRIOS series scanners from 3Shape A / S. The dental scanning system may include wireless functionality provided by a wireless networking unit. The scanning device may employ a scanning principle, such as triangulation-based scanning, confocal scanning, focal scanning, ultrasound scanning, X-ray scanning, stereo vision, motion structure, optical coherence tomography (OCT), or any other scanning principle. In one embodiment, the scanning device is operable to acquire surface information by projecting a pattern and translating a focal plane along an optical axis of the scanning device, and capturing multiple 2D images at different focal plane positions, such that each series of captured 2D images corresponding to each focal plane forms a stack of 2D images. The acquired 2D image is also referred to herein as a raw 2D image, wherein "raw" in this context means that the image has not yet been subjected to image processing. The focal plane position is preferably moved along the optical axis of the scanning system, such that 2D images captured at multiple focal plane positions along the optical axis form a stack of 2D images (also referred to herein as subscans) for a given view of the object, i.e., for a given arrangement of the scanning system relative to the object. After moving the scanning device relative to the object or imaging the object in a different view, a new stack of 2D images for that view can be captured. The focal plane position can be changed by at least one focusing element, such as a moving focusing lens. The scanning device is typically moved and angled relative to the dentition during the scanning process so that at least some sets of subscans at least partially overlap, enabling reconstruction of a digital dental 3D model by stitching together the overlapping subscans in real time, with the progress of the virtual 3D model displayed on a display as feedback to the user. The result of this stitching is a digital 3D representation of a surface that is larger than a single subscan could capture, i.e., larger than the field of view of the 3D scanning device. Stitching, also known as registration and merging, works by identifying overlapping regions of the 3D surface in the individual subscans and transforming the subscans to a common coordinate system so that the overlapping regions match, ultimately generating a digital 3D model. An Iterative Closest Point (ICP) algorithm can be used for this purpose.Another example of a scanning device is a triangulation scanner, where a time-varying pattern is projected onto the dental arch and a series of images of different pattern configurations are acquired by one or more cameras positioned at an angle relative to the projection unit.

[0173] The color texture of the dental arch can be acquired by illuminating the object with different monochromatic colors (e.g., red, green, blue alone), or by illuminating the object with polychromatic light, such as white light. The 2D image can be acquired during flashes of white light.

[0174] Typically, acquiring real-time surface information of the scanned dental arch requires a scanning device to illuminate the surface and acquire numerous 2D images. Typically, high-speed cameras are used, with frame rates ranging from 300 to 2000 2D frames per second, depending on the technology and the 2D image resolution. The scanning device must process this large amount of image data, either forwarding the raw image data stream directly to an external processing device or performing some image processing before transmitting the data to an external device or display. This process places high demands on the electronic components within the scanner, resulting in a high current demand.

[0175] The scanning device includes one or more light projectors configured to generate an illumination pattern projected onto a three-dimensional dental arch during a scanning process. The light projector(s) preferably include a light source, a mask having a spatial pattern, and one or more lenses, such as a collimating lens or a projection lens. The light source can be configured to generate light of a single wavelength or a combination of wavelengths (monochromatic or polychromatic). The wavelength combination can be generated by using a light source configured to generate light comprising different wavelengths (e.g., white light). Alternatively, the light projector(s) can include multiple light sources, such as LEDs, each generating light of different wavelengths (e.g., red, green, and blue), which can be combined to form light comprising different wavelengths. Thus, the light generated by the light source can be defined by wavelengths defining a specific color or by different wavelength ranges defining a color combination (e.g., white light). In one embodiment, the scanning device includes a light source configured to excite a dental fluorescent material to obtain fluorescence data from the dental arch. Such a light source can be configured to generate a narrow range of wavelengths. In another embodiment, the light from the light source is infrared (IR) light, which is capable of penetrating dental tissue. The light projector(s) may be a DLP projector that uses a micromirror array to generate a time-varying pattern, or a diffractive optical element (DOF), or a backlit mask projector in which a light source is placed behind a mask having a spatial pattern so that the light projected onto the surface of the dental arch is patterned. The backlit mask projector may include a collimating lens for collimating the light from the light source, the collimating lens being placed between the light source and the mask. The mask may have a checkerboard pattern so that the generated illumination pattern is a checkerboard pattern. Alternatively, the mask may have other patterns such as lines or dots.

[0176] The scanning device preferably also includes optical elements for directing light from the light source onto the dental arch surface. The specific arrangement of the optical elements depends on whether the scanning device is a focused scanning device, a scanning device using triangulation, or any other type of scanning device. A focused scanning device is further described in EP 2 442 720 B1 by the same applicant, which is incorporated herein in its entirety.

[0177] Using the optical elements of the scanning device, light reflected from the dental arch in response to illumination of the dental arch is directed to (one or more) image sensors. The (one or more) image sensors are configured to generate a plurality of images based on the incident light received from the illuminated dental arch. The image sensor unit can be a high-speed image sensor, for example, an image sensor configured to acquire images with an exposure of less than 1 / 1000 second or a frame rate exceeding 250 frames per second (fps). For example, the image sensor can be a rolling shutter (CCD) or a global shutter sensor (CMOS). The (one or more) image sensors can be monochrome sensors that include a color filter array, such as a Bayer filter and / or other filters that can be configured to substantially remove one or more color components from the reflected light and retain only other unremoved components before converting the reflected light into an electrical signal. For example, such additional filters can be used to remove a portion of the white light spectrum, such as the blue component, while retaining only the red and green components from the signal generated in response to the excitation of the fluorescent material of the tooth.

[0178] The network unit may be configured to connect the dental scanning system to a network comprising a plurality of network elements, including at least one network element configured to receive the processed data. The network unit may include a wireless network unit or a wired network unit. The wireless network unit is configured to wirelessly connect the dental scanning system to the network comprising the plurality of network elements, including at least one network element configured to receive the processed data. The wired network unit is configured to establish a wired connection between the dental scanning system and the network comprising the plurality of network elements, including the at least one network element configured to receive the processed data.

[0179] The dental scanning system preferably also includes a processor configured to generate scan data (e.g., extraoral scan data and / or intraoral scan data) by processing two-dimensional (2D) images acquired by the scanning device. The processor may be part of the scanning device. For example, the processor may include a field programmable gate array (FPGA) and / or an advanced RISC machine (ARM) processor located on the scanning device. The scan data includes information related to a three-dimensional dental arch. The scan data may include any of the following data: a 2D image, a 3D point cloud, depth data, texture data, intensity data, color data, and / or a combination thereof. For example, the scan data may include one or more point clouds, each of which includes a set of 3D points describing a three-dimensional dental arch. As another example, the scan data may include images, each of which includes image data described, for example, by image coordinates and a timestamp (x, y, t), wherein depth information can be inferred from the timestamp. The image sensor(s) of the scanning device may acquire multiple raw 2D images of the dental arch in response to illuminating the object using the one or more light projectors. The multiple raw 2D images may also be referred to herein as a stack of 2D images. These 2D images can then be provided as input to a processor, which processes the 2D images to generate scan data. Processing of the 2D images can include a step of determining which portion of each 2D image is in focus in order to infer / generate depth information from the image. The internal depth information can be used to generate a 3D point cloud, which comprises a set of 3D points in space, for example, 3D points described by a Cartesian coordinate system (x, y, z). The 3D point cloud can be generated by the processor or by another processing unit. In addition, each 2D / 3D point can include a timestamp that indicates when the 2D / 3D point was recorded, i.e., which image in the stack of 2D images the point originated from. The timestamp is associated with the z-coordinate of the 3D point, i.e., the z-coordinate can be inferred from the timestamp. Thus, the output of the processor is scan data, and the scan data can include image data and / or depth data, for example, described by image coordinates and a timestamp (x, y, t), or alternatively, described by (x, y, z). The scanning device can be configured to transmit other types of data in addition to the scan data. Examples of data include 3D information, texture information, such as infrared (IR) images, fluorescence images, reflectance color images, X-ray images, and / or combinations thereof.

[0180] The examples shown in the following figures may be executed by one or more processors 11 .

[0181] Figure 1An intraoral scanning system 1 is shown, comprising a handheld intraoral scanning device 10 configured to scan a patient's dental arch 2. In this example, scan information generated by the handheld intraoral scanning device 10 is transmitted 3, either wired or wirelessly, to an external computer 4 or server 6, which forwards the scan information to the external computer 4. The handheld intraoral scanning device 10 comprises a projection unit 5 configured to emit light 8 at near-infrared wavelengths and white wavelengths onto at least a dental arch. In another embodiment, the projection unit 5 is configured to emit light 8 at near-infrared wavelengths and white wavelengths onto at least a dental arch. In yet another embodiment, the projection unit 5 is configured to emit light 8 at different wavelengths onto at least one dental arch during respective time periods, wherein the different wavelengths include near-infrared wavelengths and visible wavelengths. The handheld intraoral scanning device 10 may comprise an image sensor unit 7 configured to capture 9 visible light information 9 and internal light information from the at least one dental arch 2 caused by the light 8 emitted by the projection unit 5. In another example, the image sensor unit 7 is configured to capture 9 visible light information and internal light information from the at least one dental arch 2 caused by visible wavelengths and near-infrared wavelengths, respectively. The system 10 includes one or more processors arranged in the handheld intraoral scanning device 10, an external computer 4 and / or a server 6, and the external computer 4. The handheld intraoral scanning device 10 may include a processor 11 among the one or more processors, and the processor is configured to process the visible light information and the internal light information into information configured to be transmitted to the external computer 4 or configured to be displayed on the display unit 4. In addition, the external device and the server 6 may each include a processor 11 among the one or more processors.

[0182] Figures 2A to 2E Different examples of determining the combined scan information 20 by the system 1 are shown. The one or more processors 11 are configured to receive visible light information 22 and internal light information 24 from the image sensor unit 7, and determine surface information 21A from the visible light information 22 in real time, so as to generate or update a three-dimensional (3D) model 29 of the dental arch 2 using the surface information. The one or more processors 11 are further configured to determine internal structure information 21B of the dental arch 2 from the internal light information 24, and determine the combined scan information 20 including the combination of the internal structure information 21B and the surface information 21A. Figure 2A In FIG, the visible light information 22 includes the surface reflection provided by the white light emitted by the handheld intraoral scanning device 10, i.e., the surface information 21A, and the internal structure information 21B is provided by the reflection of the near-infrared light emitted by the handheld intraoral scanning device 10. Figure 2A In FIG, the combined scan information 20 includes the internal structure information 21B subtracted from the surface information 21A. The combined scan information 20 includes an enhanced internal structure represented by a restoration 26A that is not visible in the near infrared information 24 but is easily identifiable in the combined scan information 20. Figure 2B In the example, the combined scan information 20 includes the surface information 21A subtracted from the internal structure information 21B. In this example, different types of restorations 26B are seen in both the internal light information 24 and the combined scan information 20, however, the contrast of the restorations 26B is improved in the combined scan information 20. Figure 2C , the projection unit 5 is configured to emit light having a near-infrared wavelength and a blue wavelength. In another example, the projection unit 5 is configured to emit light having a near-infrared wavelength, a blue wavelength, and a white wavelength. In this current example, the 3D model is generated or updated by surface information 21A, which is provided by fluorescence information 22 excited by emission light including a blue wavelength. The fluorescence information 22 includes green information 21A. The combined scan information 20 includes internal structure information 21B subtracted from the green fluorescence information 21A. The combination 20 is suitable for enhancing the visibility of the caries lesion 27. On the near-infrared image 24, the caries lesion 27 is almost invisible, however, on the combined image 20, the visibility of the caries lesion is improved. Figure 2D Shown with Figure 2C A similar example, however, Figure 2D The combined scan information 20 in the is combined in different ways. Figure 2D In this example, combined scan information 20 includes the sum of green fluorescence information 21A and internal structure information 21B. In this example, combined scan information 20 includes enhanced texture information regarding enamel 28A and tooth 28B—and therefore, the dentin-enamel junction (DEJ). It is readily apparent that enamel 28A and tooth 28B are more clearly visible in combined scan information image 20 compared to internal light information image 24. In another example, combined scan information includes the sum of internal structure information, green fluorescence information, and red fluorescence information, and this combination also demonstrates improved visibility of the DEJ relative to conventional or enhanced fluorescence information (or relative to internal light information 24).

[0183] Figure 2EAn example is shown in which the projection unit 5 emits light having a blue wavelength, a white wavelength, and a near-infrared wavelength, and the visible light information (22A, 22B, 22C) includes surface information 21D corresponding to the captured light caused by the white wavelength and information related to the fluorescence information (21A, 21C) corresponding to the captured light excited by the blue wavelength. In this example, the fluorescence information (21A, 21C) includes green fluorescence information 21A and red fluorescence information 21C. The surface information 21A is used to generate or update the 3D model 29, and the fluorescence information (21A, 21C) is used to determine the combined scan information 20. In this current example, the one or more processors are configured to determine a first difference between the internal structure information 21B and the green fluorescence information 21A and a second difference between the internal structure information 21B and the red fluorescence information 21C, and the combined scan information 20 includes the sum of the first difference and the second difference. The enhanced internal structure is associated with the caries lesion, and the internal light information image 24 and Figure 2C The lesion becomes more pronounced compared to the example shown.

[0184] refer to Figures 2A to 2E The one or more processors 11 are configured to determine fluorescence information ( 21A, 21C) of the dental arch 2 from the visible light information 22 .

[0185] Figures 3A to 3D Different examples of the one or more processors 11 receiving visible light information 22 and internal light information are shown. The one or more processors 11 are further configured to determine internal structure information 21B based on the internal light information 24 and to determine surface information and / or fluorescence information based on the visible light information 22 in real time 31 or non-real time 32. The surface information may be replaced by or combined with the fluorescence information. The one or more processors 11 are further configured to determine combined scan information 20 by combining the internal structure information 21B with the determined surface information 21A and / or fluorescence information 21A. The 3D model 29 is generated or updated by the surface information and / or fluorescence information determined in real time 31. Figure 3B , the determined surface information 21A or fluorescence information 21A for the combined scan information 20 is weighted by a first weighting coefficient (W1, 30A), while the internal area information is weighted by a second coefficient (W2, 30B). In another example, the first weighting coefficient may include a first main weighting coefficient (W1') and a first secondary weighting coefficient (W1"). The visible light information may include both surface information and fluorescence information, and in this example, the surface information is weighted by the first main weighting coefficient (W1') and the fluorescence information is weighted by the first secondary weighting coefficient (W1"). Figure 3C, the one or more processors are configured to change 33 the first and second weighting coefficients (W1, W1′, W1″, W2, 30A, 30B), and wherein the change corresponds to a change in brightness, contrast and / or transparency of the internal structure information and the visible information. The change of the weighting coefficients may be based on user input. For example, the combined scan information is displayed on a display unit of the system 1, and the user is able to change the weighting coefficients via a user interface of the system 1. If it is desired to improve the visibility of the enhanced internal structure and / or enhanced texture information of the combined scan information, the user may decide to optimize the weighting coefficients. In another example, if it is desired to see different types of enhanced internal structure and / or enhanced texture information in the combined scan information, the user may decide to optimize the weighting coefficients. The change of the weighting coefficients may be provided automatically by the one or more processors 11 based on 34 the combined scan information to be determined, or based on the internal structure and / or texture information to be enhanced by the one or more processors 11.

[0186] exist Figure 3D , the one or more processors 11 are configured to receive different weighting coefficients (W1, W1′, W1″, W2) from a memory 34 of the system 1, and wherein the different weighting coefficients (W1, W1′, W1″, W2) are used for different dental conditions to be enhanced in the combined scan information 20. Additionally, or alternatively, the one or more processors 11 are configured to determine a plurality of combined scan information 20, including combined scan information (20, 20A) and second combined scan information 20B, wherein the combined scan information (20, 20A) is different from the second combined scan information 20B. Each of the plurality of combined scan information includes a different enhanced internal structure, and wherein the one or more processors 11 are configured to tag 35 each of the plurality of combined scan information (20, 20A, 20B), and the tag 35 indicates the enhanced internal structure and / or enhanced texture information of the combined scan information (20, 20A, 20B) in the plurality of combined scan information (20, 20A, 20B).

[0187] The enhanced internal structure corresponds to the dental condition of the teeth of the patient's dental arch, wherein the dental condition corresponds to cracks, caries lesions, dentin-enamel junctions, voids, plaque, and restorations.

[0188] Figure 3E Examples of labels (35, label 1, label 2, label 3, label 4) of the multiple combined scan information (20A, 20B, 20C, 20D, 20X) are shown, and each label corresponds to a different enhanced dental condition, such as enhanced internal structure and / or enhanced texture information.

[0189] Figure 3F 、 3GFigures 3H and 3H illustrate different examples of how the one or more processors 11 determine combined scan information 20 or multiple combined scan information (20A, 20B). During a first time period T1, the image sensor unit 7 receives, for example, visible light information 22. During a second time period T2, the image sensor unit 7 receives internal light information 24, which is converted into intensity signals (21A, 21B) by each pixel of the image sensor unit 7 and combined into combined scan information 20. In this example, the combined scan information 20 includes the difference between internal structure information 21B corresponding to near-infrared information and visible light information 21A including white surface information. The first combined scan information 20A is configured to be displayed by superimposing it on a white surface image 42A received during the first time period T1. In another example, the combined scan information 20 is superimposed on the internal structure information 42B, on the blue excitation information 42C received by the image sensor unit 7 during another time period, and / or on the fluorescence information 42D excited by a blue wavelength and received by the image sensor unit 7 during another time period. Figure 3F and Figure 3G A similar processor or processors 11 are shown, however, in Figure 3G In the embodiment of the present invention, the one or more processors 11 are configured to determine a plurality of combined scan information (20A, 20B). In the present example, the combined scan information (20A, 20B) is superimposed on top of a surface image 42A, which may be a white surface image or fluorescence information. Alternatively, the combined scan information (20A, 20B) is superimposed on top of any color surface image and / or any color fluorescence information (e.g., blue, red, or green). Figure 3H It is shown that the combined scan information 20 is determined in the digital domain when the intensity signal from the image sensor unit 7 is converted into a digital signal by means of an analog-to-digital converter 43 .

[0190] Figures 4A to 4H Different examples of combined scan information images depicting different dental conditions are shown. Figure 4A 、 4B 4C and 4C show different images depicting caries in different ways. Figure 4A Inner light information 24 comprising a near infrared image of the teeth of the dental arch 2 is shown, the image including information about caries 27 . Figure 4B Shown with Figure 4A Combined scan information 20 of the same area of ​​dental arch 2 is shown, comprising the difference between near-infrared information 21B and green fluorescent information 21A. No caries are visible in green fluorescent information 21A, and by subtracting green fluorescent information 21A from near-infrared information 21B, background information unrelated to caries is reduced in near-infrared information 21B, significantly improving the contrast of caries 27. Figure 4C Shown with Figure 4B Combined scan information 20 of the same area of ​​the dental arch 2 is shown. In this example, the combined scan information 20 includes a first difference between the near infrared information 21B and the red fluorescent information 21A, and a second difference between the near infrared information 21B and the green fluorescent information 21A, wherein the first difference and the second difference are added together. In this combined scan information, the caries ratio becomes more obvious than in the first two examples. Figure 4C In FIG. 2 , the combined scan information 20 is applied to the color surface image of the dental arch 2 captured by the image sensor unit 7 based on the emission light including the white wavelength. Figure 4D and 4E Different images are shown which depict the restoration in different ways. Figure 4D The combined scan information 20 comprising the near infrared information 21B and the white surface information 21A is depicted. Figure 4E The combined scan information 20 including the subtraction of the white surface information 21A and the near infrared information 21B is depicted. The two teeth depicted on the two combined scan information images include restorations. Figure 4D In 26A, the restoration is seen, whereas in 26B the restoration is missing. Figure 4E In the NIR image 21B, only the restoration in 26B is clearly visible. Figure 4D and 4E The two combined scan information 20 are combined into hybrid scan information, and the user can then identify two restorations (26A, 26B) instead of just one restoration 26B. Figure 4F 、 4G and 4H show different images that depict the DEJ in different ways. Clearly, Figure 4G and 4H The combined scan information 20 of the two more clearly depicts the DEJ than the near infrared information 21B. Figure 4G The combined scan information 20 in the embodiment includes the sum of the internal structure information (ie, the near infrared information 21B) and the green and red fluorescence information (21A, 21C); Figure 4H In FIG, the combined scan information 20 includes the sum of the near-infrared information 21B and the green fluorescence information 21A.

[0191] Figures 5A to 5EDifferent examples of arrangements of the projection unit 5 in or on the handheld intraoral scanning device 10 are shown. The handheld intraoral scanning device 10 comprises a tip 50 which is detachably mounted or permanently mounted on a housing 51 of the handheld intraoral scanning device 10. The projection unit 5 is arranged in the tip 50 or the housing 51, or in both (50, 51). The projection unit is a separate unit, e.g. Figure 1 ; but in other examples, such as Figures 5A to 5E In the embodiment, the projection unit 5 is arranged in a plurality of units (5A, 5B). Figures 5A to 5E In the example shown in , the projection unit 5 is divided into two units ( 5A, 5B), but in other examples, the projection unit 5 is divided into two or more units. Figures 5A to 5E In one example shown in , the projection unit includes one or more first light sources 5A and at least one or more second light sources 5B, wherein the one or more first light sources 5A are configured to emit light at a near-infrared wavelength during a first set of time periods, and the one or more second light sources 5B are configured to emit light at a visible wavelength during a second set of time periods, and wherein the visible light information 22 includes information corresponding to a surface reflection 22A of the dental arch 2, which is caused by the first visible wavelength and captured by the image sensor unit 7 (not shown). In another example, the visible light information 22 includes information corresponding to fluorescence information (22B, 22C) of the dental arch 2, which is caused by the second visible wavelength and captured by the image sensor unit 7. Figures 5A to 5E In another example shown in , the projection unit 5 further includes at least one or more third light sources 5C, which are either arranged in one unit 5 together with the other light sources (5A, 5B), or arranged together with the first light source 5A or the second light source 5B. The one or more second light sources 5B are configured to emit light at a first visible wavelength during a second set of time periods, and the one or more third light sources 5C are configured to emit light at a second visible wavelength during a third set of time periods, and wherein the first visible wavelength is different from the second visible wavelength. The visible light information 22 includes information corresponding to the surface reflection 22A of the dental arch 2, which is caused by the first visible wavelength and captured by the image sensor unit 7, and the visible light information 22 includes information corresponding to the fluorescence information (22B, 22C) of the dental arch 2, which is caused by the second visible wavelength and captured by the image sensor unit 7. Specifically, in Figure 5A, the one or more first light sources 5A and / or the one or more third light sources 5C are arranged at the outer surface of the end 50 and near the window of the end 50. In another example, the one or more third light sources 5C are arranged in the housing 51. The window is configured to emit and receive light from the projection unit 5 and the dental arch 2, respectively. The image sensor unit 7 (not shown) can be arranged together with the one or more first light sources 5A, or arranged in the end 50 or in the housing 51. The image sensor unit 7 and the one or more first light sources 5A can be arranged in a configuration for transillumination of the dental arch 2. The advantage of arranging the image sensor unit 7 and the projection unit 5 on the end 50 that is detachably mounted to the housing 51 is that the handheld intraoral scanning device 10 can be adaptable to different scanning purposes and price points of the scanning device 10. For example, a low-priced scanning device 10 can be mounted to the end, the main purpose of which is to protect the optical elements of the scanning device 10 from contamination when the device 10 is inserted into the patient's mouth. A high-priced scanning device 10 can be as Figure 5A Thus, the user can switch between the low price and high price levels depending on the usage of the scanning device 10. At both price levels, the scanning device 10 is configured to perform a scan to generate or update a 3D model 29. Figure 5B In the embodiment, the one or more first light sources 5A and / or the one or more third light sources 5C are arranged inside the end 50 rather than on the outer surface of the end 50. Figure 5B The advantages of the examples depicted in Figure 5A Similar, however, Figure 5B In the embodiment, the configuration of the image sensor unit 7 (not shown) and the projection unit (5A, 5B, 5C) is not suitable for projection, but the hygienic condition of the end is improved because the end 50 is easier to clean. Figure 5C In this example, all three light sources (5A, 5B, 5C) are arranged in the tip, and thus the optical path between the window of the tip 50 and the light sources (5A, 5B, 5C) is shortened. The optical elements for guiding the light in the intraoral scanning device 10 become simpler, thereby reducing the overall size of the device 10. In this example, the image sensor unit 7 can be arranged in the tip 50, close to the light sources (5A, 5B, 5C). Figure 5D In the embodiment, the one or more first and third light sources are arranged on the outer surface of the end 50, and the one or more second light sources 5B are arranged inside the end. In this example, the one or more first and third light sources (5A, 5C) are detachably mounted. Figure 5E In FIG, all three light sources ( 5A, 5B, 5C) are arranged within a housing 51 .

[0192] Figures 6A to 6D Different examples of arrangements 60 comprising one or more light sources (5A, 5B, 5C) are shown. Figure 6AIn the embodiment, the arrangement 60 includes a plurality of light sources, which may be a plurality of first, second, or third light sources (5A, 5B, 5C). In this particular example, the arrangement includes sixteen light sources, each of which is a light emitting diode. In other examples, the arrangement 60 may include three or fewer, six or fewer, nine or fewer, twelve or fewer, or sixteen or fewer light sources (5A, 5B, 5C). Figure 6B In the embodiment, the arrangement 60 includes a mixture of different light sources configured to emit different wavelengths. For example, the arrangement includes a first group 65A of first light sources 5A, a second group 65B of second light sources 5B, and a third group 65C of third light sources 5C. In this specific example, the arrangement 60 includes a fourth group 65D of fourth light sources 5D. The fourth group includes different light sources (5A, 5B, 5C) that can each be used as a backup light source for a light source in one of the other groups (65A, 65B, 65C) that may be damaged. Figure 6C In FIG, the arrangement 60 includes nine light sources, which are equally divided into three groups (65A, 65B, 65C). Each group represents a plurality of light sources emitting the same wavelength. In this example, the first group 65A includes a plurality of first light sources 5A, the second group 65B includes a plurality of second light sources 5B, and the third group 65C includes a plurality of third light sources 5C. Figure 6D In FIG. 6 , arrangement 60 comprises three light sources configured to emit different wavelengths.

[0193] Figure 7 An arrangement 60 on the tip 50 of the scanning device 10 is shown including a plurality of light sources (5A, 5B, 5C) distributed on first and second sides of a window 70 of the tip 50. In another example, the plurality of light sources may be evenly arranged around the window 70.

[0194] Figure 8A and 8B Different examples of optical arrangements within the handheld intraoral scanning device 10 are shown. Figure 8AIn the embodiment, the optical arrangement includes a first light source 5A configured to emit light including a near-infrared wavelength; and a second light source (5B, 5C) configured to emit light including a white wavelength or a blue wavelength. The light emitted by the second light source (5B, 5C) passes through a first polarization beam splitter 75, and the light emitted by the first light source 5A passes through a polarizer 72 and is received by a beam splitter 74. The light emitted by the two light sources (5A, 5B, 5C) shares the same optical path after the beam splitter 74 and passes through a quarter (QW) wave plate 73 before reaching the dental arch 2 to be scanned. Before passing through the QW wave plate, the near-infrared light is polarized orthogonally to the light from the second light source (5B, 5C). The near-infrared light is circularly polarized clockwise after the QW wave plate 73. The polarization state of the QW wave plate 73 must change between the light from different light sources (5A, 5B, 5C), and thus, the quarter wave plate can be a rotating quarter wave plate 73 or an adjustable wave plate based on liquid crystal. Figure 8B and Figure 8A Similarly, however, polarizer 72 and beam splitter 74 are combined into a second polarizing beam splitter 75B. Figure 8A and 8B In the example shown in FIG, dental arch 2 is illuminated by a polarizing beam splitter. Due to the polarizing beam splitter, light reflected from the tooth surface (so-called specularly reflected light) cannot reach image sensor unit 7. Thus, only light scattered from the interior of the tooth, which has changed its polarization orientation, reaches image sensor unit 7. This significantly improves the quality of internal light information.

[0195] Figure 9A and 9BAn example of a handheld intraoral scanning device 10 is shown, comprising another image sensor unit 7B with a linear variable bandpass filter 80 disposed on top of the image sensor unit 7B. The other image sensor unit 7B is configured to capture 9 reflected near-infrared wavelengths emitted by the projection unit 5. In this example, the projection unit comprises one or more broadband light-emitting diodes configured to emit light at wavelengths between 850 nm and 1100 nm. The center wavelength of the bandpass filter 80 varies across the longitudinal length of the filter 80 while remaining constant along its horizontal length. The filter 80 is aligned with the other image sensor unit 7B such that each row of pixels (R1-R6) is constrained to a specific center wavelength of the bandpass filter 80. For example, the pixels in row R1 are constrained to a center wavelength of approximately 850 nm, while the pixels in row R6 are constrained to a center wavelength of approximately 1100 nm. Using a single emitted light pulse from a broadband light emitting diode, the other image sensor unit 7B is configured to capture multiple reflections of wavelengths between 850 nm and 1100 nm, i.e., internal light information 24. Based on the captured internal light information 24, the one or more processors 11 are configured to determine enhanced internal structure depth information of one or more teeth of the dental arch 2. First, the one or more processors 11 are configured to determine multiple internal structure information based on the captured internal light information caused by different near-infrared wavelengths captured by the image sensor unit 7B. Second, the one or more processors 11 are configured to determine multiple combined scan information (20A, 20B), wherein each of the multiple combined scan information (20A, 20B) is determined based on each of the multiple internal structure information and the visible light information. The multiple combined scan information (2A, 2B) corresponds to a different near-infrared wavelength, and each near-infrared wavelength corresponds to a penetration depth of the tooth. The relationship between the near-infrared wavelength and the corresponding penetration depth in the tooth is stored in a memory unit of the system 1. The one or more processors 11 are configured to identify enhanced internal structure information in one or more of the plurality of combined scan information (2A, 2B). The one or more processors are then capable of determining a longest near-infrared wavelength at which the enhanced internal structure can be identified in one of the plurality of combined scan information, and then determining internal depth information based on the longest near-infrared wavelength and a stored relationship between the near-infrared wavelength and a penetration depth of each near-infrared wavelength in the tooth.

[0196] Figure 10A The relationship between near infrared wavelengths (λ1, λ2, λ3) and corresponding penetration depths in the tooth (depth 1, depth 2, depth 3) is shown 100. This relationship is stored in a memory unit of the system 1. Figure 10BThe one or more processors 11 are shown configured to determine depth information 104 of an enhanced internal structure 102 identified in a plurality of combined scan information (20A, 20B, 20C). In this specific example, the one or more processors 11 receive at least three pieces of internal light information captured based on three different near-infrared wavelengths (λ1, λ2, λ3) and visible light information 24 captured based on a white wavelength or a blue wavelength, and determine at least three pieces of internal structure information 21B based on the at least three pieces of internal light information 24. The plurality of combined scan information (20A, 20B, 20C) is determined based on the at least three pieces of internal structure information 21B and the visible light information 21A. The one or more processors 11 are further configured to identify the enhanced internal structure 102 in one or more of the plurality of combined scan information (20A, 20B, 20C) and determine 104 the longest near-infrared wavelength of the different near-infrared wavelengths (λ1, λ2, λ3), wherein the enhanced internal structure is identified in one of the plurality of combined scan information (20A, 20B, 20C). Based on the longest near infrared wavelength, the one or more processors 11 are configured to determine the internal depth information of the enhanced internal structure. Figure 10C In the embodiment of the present invention, the one or more processors 11 are configured to determine 104 depth internal information of the enhanced internal structure based on the longest near-infrared wavelength and the relationship between the near-infrared wavelengths stored in the memory unit 106 of the system 1 and the corresponding penetration depth of the tooth. In this specific example, the system 1 is limited to three different near-infrared wavelengths. In another example, the number of different near-infrared wavelengths in the system 1 is limited by the resolution of the image sensor unit 7B and the resolution of the linear variable bandpass filter. It may then be necessary to estimate sub-interior depth information of the enhanced internal structure that is between or longer than the near-infrared wavelengths (λ1, λ2, λ3) available to the projection unit 5. Therefore, a trained neural network may be required to perform such estimation. The trained neural network is part of the system 1. First, the one or more processors 11 are configured to determine first depth information and second depth information 104 based on the combined scan information 20A and the second combined scan information 20B of the plurality of scan information (20A, 20B, 20C), respectively, and then determine the sub-interior depth information 104 based on the trained neural network that receives the first and second depth information. The neural network is trained based on a plurality of combined scans, the combined scans being determined based on different near-infrared wavelengths and the relationship between the near-infrared wavelengths and corresponding penetration depths in the teeth of one or more patients. In another example, the neural network is trained based on X-ray scans or OCT scans of one or more patients. The neural network may include one or more of the following topologies: a convolutional neural network (CNN), a three-ring model, a persistent homology method, and algebraic topology.

[0197] Figure 11 An example of how to improve the information of the combined scan information 20 is shown. In this example, captured internal light information 24 has been obtained from different angles (α1, α2, α3, α4, α5, α6, α7) between the dental arch 2 and the image sensor unit 7 (not shown in the figure). Subsequently, the one or more processors 11 are configured to combine the captured internal light information 24 from different angles. The combination can be an average or weighted average of the captured internal light information 24 from different angles.

[0198] Figure 12 One or more processors 11 are shown configured to determine hybrid scan information 120 from the plurality of combined scan information (20A, 20B, 20C). The hybrid scan information 120 includes a plurality of channels, to which each of the plurality of combined scan information is assigned. The result is an image comprising the hybrid scan information 120, in which internal structure information and / or enhanced texture information is superimposed on top of each other. Each of the plurality of channels is assigned a color. The colors can be different. Figures 13A to 13C The multiple channels (130A-130C) of the mixed scan information 120 are shown. Figure 13A In the embodiment, the mixed scan information 120 includes at least three layers of combined scan information (CS, 20), which are assigned to at least three channels (130A, 130B, 130C) of the plurality of channels (130). Figure 13B In the example, the mixed scan information 120 also includes at least three combined scan information (CS, 20), which are assigned to at least three channels (130A, 130B, 130C, 130D). However, in this example, channel 2 (130B) is empty because the color assigned to channel 2 is not ideal for visualizing the enhanced internal features in the three combined scan information. Figure 13C In the embodiment of the present invention, each of the plurality of channels (130A, 130B, 130C) is weighted by a channel weighting coefficient (W1, W2, W3). The one or more processors 11 are configured to change the weighting coefficients (W1, W2, W3) to change the brightness, contrast and / or transparency of the plurality of combined scan information.

[0199] Figure 14A depicts a near infrared image including internal structure information 24, while Figure 14B The hybrid scan information 120 is depicted as including four combined scan information (assigned to different channels 130A, 130B, 130C, 130D). In this example, the four combined scan information are as follows:

[0200] Channel 1 => assigned to grayscale and includes first combined scan information 20A, which includes the difference between white surface information 21A and internal structure information 21B;

[0201] Channel 2 => assigned to blue and includes second combined scan information 20B, which includes the difference between white surface information 21A and internal structure information 21B;

[0202] Channel 3 => assigned to blue, and includes third combined scan information 20C, which includes the difference between the internal structure information 21B and the white surface information 21A; and

[0203] Channel 4 => assigned to blue, and includes fourth combined scan information 20D, which includes the difference between internal structure information 21B and green fluorescence information 21A.

[0204] Figure 15A 、 15B 15C shows a display unit 150, which is configured to display the combined scan information 20 based on the position of the marker 151 and the relative angle between the marker 151 and the 3D model 29 on the display unit 150 of the system 1. The one or more processors 11 are configured to rotate the 3D model (see Figure 15B ) or change the position of the marker (see Figure 15C ) to change the relative angle. In addition, the one or more processors are configured to identify, from both the 3D model 29 of the dental arch 2 and the plurality of combined scan information (not shown), the combined scan information 20 in the plurality of combined scan information that approximates the relative angle and position of the marker 151 relative to the 3D model 29 of the dental arch 2, wherein each of the plurality of combined scan information includes internal light information and visible light information captured at a certain angle and position; and display the identified combined scan information 20 determined for the angle and position that approximates the angle and position of the marker 151 relative to the 3D model 29 of the dental arch 2.

[0205] exist Figure 16In the example, the display unit 150 displays a slider 160, a label selector 161, and a marker 151. In this particular example, the label selector 161 is configured to select one or more combined scan information associated with one or more enhanced internal structures, such as caries, restorations, and / or DEJs. Based on the position of the marker and the selection made by the label selector 161, the one or more processors 11 are configured to select one or more combined scan information (20A, 20B, 20C) to be displayed on the display unit 150, the information associated with the relative position of the marker to the 3D model and the selected enhanced internal structure. In this example, the user of the system 1 has explicitly selected, via the label selector 161, that the displayed combined scan information should include enhanced internal structure information associated with caries and restorations, and by moving the slider 160, the user can switch between the two combined scan information (20A, 20B) to be displayed. In this example, the slider 160 is positioned on top of the combined scan information (20A, 20B), but in other examples, the slider 160 can be positioned next to the combined scan information (20A, 20B). Slider 160 provides an intuitive way to change between different combinations of scan information to be displayed.

[0206] exist Figure 17 In the embodiment of the present invention, the one or more processors 11 have identified enhanced internal structure information of a plurality of combined scan information (20A, 20B, 20C) and aligned the enhanced internal structure information (170A, 170B) with the 3D model 29 visualized on the display unit 150. The type of enhanced internal structure information has been selected by the label selector 161. The status of the displayed enhanced internal structure information (170A, 170B) is indicated by the color code 171 on the 3D model 29. In this example, the user wishes to display 150 a caries lesion on the 3D model 29 by selecting "Caries" on the label selector 161. The 3D model depicts a patient having a severe caries lesion 170A and an initial caries lesion 170B. In another example, the user can select 151 an enhanced internal structure on the 3D model, which should be displayed on the 2D image including the corresponding combined scan information 20. The one or more combined scan information 20 can be displayed next to or on the 3D model.

[0207] exist Figure 18In the embodiment of the present invention, the enhanced internal structure information (170A, 170B) is not directly visualized on the 3D model 29. Instead, the teeth including at least one enhanced internal structure information (170A, 170B) identified by the one or more processors 11 based on the one or more combined scan information 20 are highlighted on the 3D model. An example of highlighting a tooth is applying a color to the tooth, applying a circumferential marking line around the tooth, applying a visual mark on the tooth, such as an asterisk, an exclamation mark, etc. By clicking on the highlighted tooth, one or more images including one or more combined scan information 20 or hybrid scan information 120 related to the highlighted tooth are displayed next to the 3D model 29. The highlighted display of the tooth may depend on the dental condition selected by the label selector 161. In this example, the user wants to highlight a tooth with caries, and the user has clicked on one of the highlighted teeth and sees two images including the combined scan information of the highlighted tooth from two different angles. In another example, the user may have selected two dental conditions via the label selector 161, and in this example, it would be appropriate to display the hybrid scan information 120 including the enhanced internal structure associated with the selected dental conditions. Alternatively, two or more combined scan information (20A, 20B) associated with the selected dental conditions may be displayed alongside the 3D model.

[0208] Figure 19A and 19B Different examples of a display unit 150 are shown, which displays a 3D model 29 including both the mandible and the maxilla, and next to the 3D model 29, displays the combined scan information 20 or the mixed scan information 120 depending on the position of the marker 150 and the viewing angle selected by the viewing angle selector 190 of the display unit 150. Figure 19A In , the user has selected an area on the 3D model 29 using the marker 151 and the bite view 190; and Figure 19B In the , the viewing angle has changed to buccal 190. Figure 19C In the middle, mark 151 and Figure 19A and 19B At least three pieces of combined scan information (20A, 20B, 20C) and / or mixed scan information (120A, 120B, 120C) of a marked area 151 on the 3D model 29, captured from different angles by a handheld intraoral scanning device, are displayed next to the 3D model 29. In this example, the one or more processors 11 are configured to select the plurality of pieces of combined scan information (20A, 20B, 20C) or mixed scan information (120A, 120B, 120C) based on the position of the marker 151.

[0209] Figure 20Another example of a display unit 150 is shown. In this example, hybrid scan information 120 is displayed next to a 3D model 29, wherein the plurality of combined scan information (20A, 20B, 20C) in the hybrid scan information 120 is determined based on the position of a marker 150 on the 3D model 29. The one or more processors 11 are configured to add or remove combined scan information to or from the hybrid scan information 120 based on the position of a slider 200.

[0210] Figure 21 An example of a display unit 150 during a scanning process is shown. In this example, a user can scan a dental arch 2 while a 3D model 29 is being generated or updated in real time, and different colors and / or text labels can be added to areas on the 3D model while the 3D model is being generated or updated. The colors and / or text labels of specific areas on the 3D model indicate the quality of the captured visible light information and / or internal light information for different purposes, such as for generating / updating the 3D model, surface diagnosis (i.e., plaque), and deep diagnosis (i.e., cracks, caries lesions, etc.). The quality of the scan depends on the amount of information (22, 24) captured by the image sensor unit 7 or the consistency of the scan. In this particular example, the display unit 150 includes a scan quality bar 210 that includes colors indicating the quality of the scan for different purposes. In another example, the bar 210 may not be displayed, and instead the quality may be indicated directly on the 3D model via colors and / or text labels (211A, 211B, 211C, 211D, 211E). A specific area 211E marked with a first color and the text label "Surface Scan" indicates that the amount of visible light information received is just sufficient to generate / update the 3D model so that it reflects the area of ​​the patient's dental arch 2. Another specific area 211B of the 3D model is marked with a different color and the text label "Diagnosis Mode 1," indicating that the amount of visible light information and internal light information captured by the image sensor units (7, 7B) is just sufficient to generate / update the 3D model and perform a reliable surface diagnosis of the other specific area. The remaining areas (211A, 211C, 211D) of the 3D model 29 are marked with yet another different color and the text label "Diagnosis Mode 2," indicating that the amount of visible light information and internal light information captured by the image sensor units (7, 7B) is sufficient to generate / update the 3D model and perform a surface diagnosis as well as a deep diagnosis. The diagnosis can be performed by the user or by the one or more processors 11 based on the combined scan information 20 or multiple combined scan information (20A, 20B, 20C) and a trained neural network.

[0211] Figure 22A and 22BFIG2 shows an example of how to wirelessly transmit visible light information 22 and internal light information 24 through the wireless communication interface 3 of the system 1. The wireless communication interface 3 may be located between the handheld intraoral scanning device 10 and a processor 11 or a group of processors 11 among the one or more processors 11. Figure 22A In the embodiment, the visible light information 22 and the internal light information 24 are transmitted in groups (220A, 220B), and each of the groups (220A, 220B) includes a plurality of visible light information 22 data pulses (V) to be transmitted and one internal light information 24 data pulse (I). In each of the groups (220A, 220B), the data pulses to be transmitted correspond to the same area of ​​the dental arch 2. Figure 22B Shown with Figure 22A However, the number of visible light information 22 data pulses (V) is equal to the number of internal light information 24 data pulses (I) to be transmitted. Figure 22C , the visible light information 22 data pulses (V) and the internal light information 24 data pulses (I) corresponding to the same area of ​​the dental arch 2 include the same identifier. In this example, the wireless transmission 3 of the visible light information 22 data pulses (V) includes a first identifier (ID1), and the wireless transmission 3 of the internal light information 24 data pulses (I) includes a second identifier (ID1'), and wherein the combined scanning information 20 includes a combination of the internal structure information 21B determined by the internal light information 24 data pulses (I) including the second identifier (ID1') and the visible light information 22 data pulses (V) including the first identifier (ID1), and wherein the first identifier (ID1) matches the second identifier (ID1'). Figure 22D , another example of the wireless communication interface 6 is shown. In this example, the visible light information 22 pulse data (V) is transmitted in real time in the first wireless link 3A of the wireless communication interface 3, while the internal light information 24 pulse data (I) is transmitted in the second wireless link 3B of the wireless communication interface 3. The first wireless link 3A and the second wireless link 3B can be two independent channels of a wireless communication protocol, such as WIFI, Bluetooth, low-power Bluetooth or a 60GHz wireless link. In another example, the first wireless link 3A and the second wireless link 3B can be two different communication protocols, for example, the first wireless link 3A is based on WIFI, while the second wireless link 3B is based on Bluetooth or low-power Bluetooth. The second wireless link 3B can transmit the pulse data (I) in real time or non-real time according to the scanning mode of the system 1.

[0212] The handheld intraoral scanning device 10 is configured to emit light having different wavelengths during different time periods. The different time periods are grouped into different wavelengths, for example, a first group of time periods and a second group of time periods, where the first group includes light emitted at near-infrared wavelengths and the second group includes light emitted at visible wavelengths. These groups are arranged accordingly within the time frame. Figure 23A A scanning sequence performed by the handheld intraoral scanning device 10 is shown, and in this example, the scanning sequence includes two time frames (F1, F2), where each time frame includes a first group (T1, T1'), a second group (T2, T2', T2"), and a third group (T3, T3', T3") of time periods. In this example, the first group includes near-infrared wavelengths, the second group includes white wavelengths, and the third group includes blue wavelengths. The two time frames include the same sequence of different wavelengths, but in another example, the sequence of different wavelengths can be changed according to user preference or based on the quality of the 3D model being generated or updated. For example, the scanner 10 is scanning an area where the quality of the surface is sufficient for generating the 3D model 29, but more information is needed to enable the one or more processors 11 or the user to diagnose a dental condition of the patient's dental arch 2. In this example, the next time frame will then include more time periods of, for example, blue and near-infrared wavelengths than white wavelengths. Each group of time periods includes a repetition rate. For example, the time frame (F1, F2) includes a first repetition rate (1.RR) of the time periods of the first group of time periods (T1, T1'), a second repetition rate (2.RR) of the time periods of the second group of time periods (T2, T2', T2"), and a third repetition rate (3.RR) of the time periods of the third group of time periods (T3, T3', T3"). Figure 23B , the one or more processors 11 are shown configured to determine a repetition rate based on a scanning mode. The scanning mode can be determined 231 by the one or more processors 11 or by a user via user input to the system 1. In this example, the one or more processors 11 or the user can select between a first diagnostic mode 230A, a second diagnostic mode 230B, and a first surface scanning mode 230C. The first diagnostic mode may be suitable for performing surface diagnostics (e.g., plaque, restorations, etc.), the second diagnostic mode may be suitable for performing deep diagnostics (e.g., cracks, caries lesions, etc.), and the first surface scanning mode may be suitable for generating surface information into a 3D model 29. In the first diagnostic mode 230A, the first repetition rate (1.RR) is greater than the second repetition rate (2.RR), and the third repetition rate (3.RR) is insignificant because only two different wavelengths are used. In the second diagnostic mode 230B, all three repetition rates (1.RR, 2.RR, 3.RR) are the same, while in the first surface scanning mode 230C, the first repetition rate (1.RR) is less than the second repetition rate (2.RR). In another example, it may be possible to select a second surface scanning mode 230D (not shown) and in which the first and third repetition rates are zero and only the second repetition rate is present, ie set to a level above zero.

[0213] Although some embodiments have been described and shown in detail, the present disclosure is not limited to these details, but can also be implemented in other ways within the scope of the subject matter defined by the appended claims. In particular, it is to be understood that other embodiments can be used and structural and functional modifications can be made without departing from the scope of the present invention.

[0214] The benefits, other advantages and solutions to problems have been described herein in conjunction with specific embodiments. However, these benefits, advantages, solutions to problems, and any component(s) / unit(s) that may cause any benefit, advantage or solution to arise or become more significant, should not be understood as key, required or essential features or components / elements of any or all rights or inventions. Therefore, the scope of the invention is limited only by the appended claims, wherein, unless expressly stated otherwise, references to singular components / units / elements are not intended to mean "one and only one", but "one or more". A claim may refer to any of the previous claims, and "any" is understood to mean "any one or more" of the previous claims.

[0215] It is intended that structural features of the apparatus as described above in the detailed description and / or claims may be combined with steps of the method when appropriately replaced by corresponding procedures.

[0216] Unless expressly stated otherwise, the singular forms "a", "an" and "the" as used are intended to include the plural forms as well (i.e., to have the meaning of "at least one"). It will also be understood that, when used in this specification, the terms "comprises", "comprising", "including" and / or "comprising" specify the presence of stated features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It will also be understood that when an element is referred to as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, but there may also be intermediate elements, unless expressly stated otherwise. In addition, "connected" or "coupled" as used herein may include wireless connections or couplings. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. The steps of any disclosed method are not limited to the exact order described herein, unless expressly stated otherwise.

[0217] It should be understood that references throughout this specification to "one embodiment" or "an embodiment" or "an aspect" or features that are included in a "may" manner indicate that the specific features, structures, or characteristics described in conjunction with the embodiment are included in at least one embodiment of the present disclosure. In addition, these specific features, structures, or characteristics may be combined in one or more embodiments of the present disclosure as appropriate. The foregoing description is intended to enable those skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects.

[0218] The claims are not intended to be limited to the aspects shown herein, but are to be accorded the full scope consistent with the wording of the claims. Reference to a singular element is not intended to mean "one and only one," but rather "one or more," unless expressly stated otherwise. The term "some" refers to one or more, unless expressly stated otherwise.

[0219] project

[0220] 1. An intraoral scanning system configured to provide combined scan information, the system comprising a handheld intraoral scanning device, the handheld intraoral scanning device comprising:

[0221] a projection unit configured to emit light having different wavelengths onto at least one dental arch during time periods, wherein the different wavelengths include near infrared wavelengths and visible wavelengths,

[0222] an image sensor unit configured to capture visible light information and internal light information from the at least one dental arch caused by visible wavelengths and near infrared wavelengths, respectively, and

[0223] The system further includes one or more processors operably connected to the image sensor unit, the one or more processors being configured to:

[0224] Receive visible light information and internal light information,

[0225] determining surface information in real time from the visible light information in order to generate or update a three-dimensional (3D) model of the dental arch using the surface information,

[0226] Determine the internal structure of the dental arch from the internal light information, and

[0227] Determining combined scan information comprising a combination of the internal structure information and the visible light information.

[0228] 2. The intraoral scanning system of item 1, wherein the one or more processors are configured to determine fluorescence information of the dental arch from the visible light information.

[0229] 3. The intraoral scanning system according to item 1 or 2, wherein the combined scanning information includes the difference between the internal structure information and the visible light information, or the difference between the internal structure information and the fluorescence information.

[0230] 4. The intraoral scanning system according to item 2, wherein the fluorescence information includes green fluorescence information and / or red fluorescence information.

[0231] 5. An intraoral scanning system according to item 4, wherein the one or more processors are configured to determine a first difference between the internal structure information and the green fluorescence information, and a second difference between the internal structure information and the red fluorescence information, and wherein the combined scanning information includes the sum of the first difference and the second difference.

[0232] 6. The intraoral scanning system according to item 4, wherein the combined scanning information includes the sum of the internal structure information, the green fluorescence information and the red fluorescence information.

[0233] 7. The intraoral scanning system according to any of items 1 or 2, wherein the combined scan information comprises the difference between the internal structure information and the surface information, or vice versa.

[0234] 8. An intraoral scanning system according to any of the preceding items, wherein the combination corresponds to a light intensity difference between the light intensity of the internal structure information and the light intensity of the visible light information, or vice versa, or a light intensity sum between the light intensity of the internal structure information and the light intensity of the visible light information.

[0235] 9. An intraoral scanning system according to any of the preceding items, wherein internal structure information and visible light information are weighted in the combined scan information, and wherein the internal structure information is weighted by a first weighting coefficient and the visible light information is weighted by a second weighting coefficient.

[0236] 10. An intraoral scanning system according to item 9, wherein the one or more processors are configured to change the first weighting coefficient and the second weighting coefficient, and wherein the change corresponds to a change in brightness, contrast and / or transparency of the internal structure information and the visible light information.

[0237] 10B. The intraoral scanning system according to item 9 or 10, wherein the visible light information includes both surface information and fluorescence information, the surface information is weighted by a first primary weighting coefficient, and the fluorescence information is weighted by a first secondary weighting coefficient.

[0238] 11. An intraoral scanning system according to any of the preceding items, wherein the one or more processors are configured to determine a plurality of combined scan information including the combined scan information and second combined scan information, wherein the combined scan information is different from the second combined scan information.

[0239] 12. An intraoral scanning system according to item 11, wherein each of the multiple combined scanning information includes a different enhanced internal structure, and wherein the one or more processors are configured to label each of the multiple combined scanning information, and the label indicates the enhanced internal structure and / or enhanced texture information of the combined scanning information in the multiple combined scanning information.

[0240] 13. The intraoral scanning system of claim 12, wherein the enhanced internal structure corresponds to a dental condition in the teeth of the patient's dental arch, wherein the dental condition corresponds to cracks, caries lesions, dentin-enamel junctions, voids, plaque, and restorations.

[0241] 14. An intraoral scanning system according to any of the preceding items, wherein the projection unit comprises one or more first light sources and at least one or more second light sources, wherein the one or more first light sources are configured to emit light at a near-infrared wavelength during a first set of time periods, and the one or more second light sources are configured to emit light at a visible wavelength during a second set of time periods, and wherein the visible light information comprises information corresponding to surface reflections of the dental arch caused by the first visible wavelength and captured by the image sensor unit, or the visible light information comprises information corresponding to fluorescence information of the dental arch caused by the second visible wavelength and captured by the image sensor unit.

[0242] 15. An intraoral scanning system according to any of the preceding items, wherein the projection unit comprises one or more first light sources, at least one or more second light sources and at least one or more third light sources, wherein the one or more first light sources are configured to emit light at a near-infrared wavelength during a first set of time periods, the one or more second light sources are configured to emit light at a first visible wavelength during a second set of time periods, and the one or more third light sources are configured to emit light at a second visible wavelength during a third set of time periods, and wherein the first visible wavelength is different from the second visible wavelength, and wherein the visible light information comprises information corresponding to surface reflections of the dental arch caused by the first visible wavelength and captured by the image sensor unit, and the visible light information comprises information corresponding to fluorescence information of the dental arch caused by the second visible wavelength and captured by the image sensor unit.

[0243] 16. An intraoral scanning system according to items 14 and / or 15, wherein the one or more processors are configured to determine surface information provided by surface reflections of a first visible wavelength, and the combined scanning information includes a combination of internal structure information and visible light information including surface reflections of the first visible wavelength, and / or, the combined scanning information includes a combination of internal structure information and visible light information including fluorescence information of a second visible wavelength.

[0244] 17. An intraoral scanning system according to any of the preceding items, wherein the near infrared wavelength is between 701 nm and 2500 nm, the first visible wavelength is between 380 nm and 700 nm, the second visible wavelength is between 100 nm and 500 nm, and the visible wavelength is between 100 nm and 700 nm.

[0245] 18. The intraoral scanning system according to any of the preceding items, wherein the projection unit is configured to emit light having different near-infrared wavelengths, and the image sensor unit is configured to capture internal light information from the at least one dental arch caused by the different near-infrared wavelengths, and the one or more processors are configured to determine:

[0246] Multiple internal structure information based on captured internal light information caused by different near-infrared wavelengths, and

[0247] A plurality of combined scanning information, wherein each of the plurality of combined scanning information is determined based on each of the plurality of internal structure information and visible light information.

[0248] 19. An intraoral scanning system according to item 18, comprising a memory unit including a relationship between near-infrared wavelength and penetration depth in a tooth, and wherein the one or more processors are configured to determine a longest near-infrared wavelength among different near-infrared wavelengths, wherein the one or more processors identify an enhanced internal structure in one of the multiple combined scanning information, and wherein the one or more processors are configured to determine internal depth information of the enhanced internal structure based on the longest near-infrared wavelength and the stored relationship between the near-infrared wavelength and the penetration depth of the tooth.

[0249] 20. An intraoral scanning system according to item 18, wherein the one or more processors are configured to determine depth information of the enhanced internal structure of one or more teeth of the dental arch, wherein the determined depth information is based on the multiple combined scanning information, and the multiple combined scanning information is determined based on the multiple internal structure information and the visible light information.

[0250] 21. An intraoral scanning system according to item 19, wherein the internal depth information is determined based on a trained neural network, wherein the trained neural network is configured to receive the multiple combined scanning information and visible light information, and estimate one or more sub-internal depth information between the first depth information and the second depth information, wherein the first depth information and the second depth information are respectively determined by the first combined scanning information and the second combined scanning information in the multiple combined scanning information.

[0251] 22. An intraoral scanning system according to item 21, wherein the trained neural network is trained based on a training data set comprising visible light information of dental arches of other patients and multiple combined scanning information.

[0252] 23. An intraoral scanning system according to item 22, wherein the multiple combined scanning information includes handheld intraoral scanning information, X-ray scanning information, and OCT scanning information of the dental arch of the same patient.

[0253] 24. An intraoral scanning system according to any of items 21 to 23, wherein the trained neural network comprises one or more of the following topologies: a convolutional neural network (CNN), a three-ring model, a persistent homology method, and an algebraic topology.

[0254] 25. An intraoral scanning system according to any of the preceding items, wherein the image sensor unit comprises at least one image sensor configured to capture light in the range of 100 nm to 2500 nm, or the image sensor unit comprises a plurality of image sensors, wherein each of the plurality of image sensors is configured to capture light between 701 nm to 2500 nm, 100 nm to 500 nm, or 380 nm to 700 nm.

[0255] 26. An intraoral scanning system according to any of the preceding items, wherein internal structure information is determined based on a plurality of captured internal light information, wherein the plurality of captured internal light information is captured by an image sensor unit at different angles between the dental arch and the image sensor unit.

[0256] 27. An intraoral scanning system according to item 26, wherein the internal structure information is determined based on an average or weighted average of the multiple captured internal light information.

[0257] 28. An intraoral scanning system according to item 2, wherein the one or more processors are configured to determine surface information and / or fluorescence information based on multiple captured visible light information, wherein the multiple captured visible light information are captured by the image sensor unit at different angles between the dental arch and the image sensor unit.

[0258] 29. An intraoral scanning system according to item 28, wherein the determined surface information and / or fluorescence information is based on an average or weighted average of the multiple captured visible light information.

[0259] 30. The intraoral scanning system according to item 11, wherein the one or more processors are configured to determine hybrid scanning information including the plurality of combined scanning information.

[0260] 31. An intraoral scanning system according to item 30, wherein the mixed scanning information includes a plurality of channels, wherein each of the plurality of channels corresponds to each of the plurality of combined scanning information.

[0261] 32. The intraoral scanning system according to any of items 30 and 31, wherein the one or more processors are configured to weight each of the plurality of channels differently using a channel weighting coefficient.

[0262] 33. An intraoral scanning system according to item 32, wherein a change in the channel weighting coefficient corresponds to a change in brightness, contrast and / or transparency of the combined scanning information corresponding to a channel in the plurality of channels.

[0263] 34. The intraoral scanning system according to any of items 31 to 33, wherein each of the plurality of channels is assigned a color.

[0264] 35. An intraoral scanning system according to any of items 31 to 34, wherein the multiple channels include: a first channel corresponding to background information including first combined scanning information among the multiple combined scanning information; and a second channel corresponding to first stacked information including second combined scanning information among the multiple combined scanning information, and wherein the first stacked information is aligned with and stacked on the background information.

[0265] 36. An intraoral scanning system according to any of items 31 to 35, wherein each of the multiple channels includes a single combination scanning information from the multiple combination scanning information, or a combination of combination scanning information from the multiple combination scanning information, and wherein the combined combination scanning information includes a combination of at least two combination scanning information from the multiple combination scanning information.

[0266] 37. The intraoral scanning system according to item 36, wherein the combination of the at least two combined scan information comprises the sum of the first combined scan information of the plurality of scan information and the second combined scan information of the plurality of scan information.

[0267] 38. The intraoral scanning system according to item 37, wherein the combination of the at least two combined scan information comprises a difference between a first combined scan information among the plurality of scan information and a second combined scan information among the plurality of scan information.

[0268] 39. The intraoral scanning system according to any of the preceding items, wherein the one or more processors are configured to display the combined scan information on a display unit of the intraoral scanning system.

[0269] 40. The intraoral scanning system according to any of the preceding items, wherein the one or more processors are configured to determine enhanced internal structure and / or enhanced texture information based on the combined scan information.

[0270] 41. An intraoral scanning system according to item 40, wherein the one or more processors are configured to apply enhanced internal structure and / or enhanced texture information to a 3D model or a 2D surface image of one or more teeth of a dental arch.

[0271] 42. An intraoral scanning system according to any of items 19 to 24 and item 41, wherein the one or more processors are configured to display internal depth information and / or enhanced texture information corresponding to the enhanced internal structure on a display unit of the system.

[0272] 43. An intraoral scanning system according to item 42, wherein the one or more processors are configured to display the internal depth information on the 3D model, on the 2D surface image, next to the 3D model, or next to the 2D surface on the display unit.

[0273] 44. The intraoral scanning system according to item 11, wherein the one or more processors are configured to:

[0274] Displaying a three-dimensional (3D) model of the dental arch on a display unit of the intraoral scanning system;

[0275] displaying a marker on a portion of the 3D model of the dental arch on the display unit;

[0276] Changing the relative position between the marker and the 3D model of the dental arch based on input from a user input device of the intraoral scanning system;

[0277] identifying, from both the 3D model of the dental arch and the plurality of combined scans, combined scan information in the plurality of combined scans that approximates a relative angle and position of the marker relative to the 3D model of the dental arch, wherein each of the plurality of combined scans includes internal light information and visible light information captured at an angle and position; and

[0278] • Displaying identified combined scan information determined for angles and positions approximating the angles and positions between the markers relative to the 3D model of the dental arch.

[0279] 45. The intraoral scanning system according to item 11, wherein the one or more processors are configured to:

[0280] Displaying a three-dimensional (3D) model of the dental arch on a display unit of the intraoral scanning system;

[0281] Displaying a marker (view marker, cursor) on a portion of the 3D model of the dental arch on a display unit of the system;

[0282] As the user changes the relative position between the marker and the 3D model of the patient's dental arch based on user input, continuously:

[0283] o From the 3D model of the dental arch and the plurality of combined scans, identifying a set of combined scans of the plurality of combined scans that are determined at an angle and position that approximates the angle and position of the marker relative to the displayed 3D model of the dental arch, wherein:

[0284] The plurality of combined scanning information includes a set of combined scanning information determined for internal light information and visible light information obtained at the same angle and position relative to the dental arch; and

[0285] o Displaying on the display unit the at least one of the set of combined scan information corresponding to an angle and position approximating the angle and position of the marker relative to the displayed 3D model of the dental arch.

[0286] 46. ​​The intraoral scanning system according to item 11, wherein the one or more processors are configured to:

[0287] receiving one or more of the plurality of combined scans including the internal structure based on user input;

[0288] associating the one or more of the plurality of combined scan information with a 3D model to associate positions of the one or more of the plurality of combined scan information with corresponding positions in the 3D model; and

[0289] Displaying the 3D model on a display unit of the system, which shows a cross-section through the 3D model, wherein the cross-section includes the one or more of the plurality of combined scan information, showing the internal structure including the internal structure.

[0290] 47. The intraoral scanning system according to item 12, wherein the one or more processors are configured to:

[0291] displaying a label selector in a user interface of the intraoral scanning system, the label selector configured to select one or more of the plurality of combined scan information to be labeled based on user input,

[0292] selecting one or more regions of interest on the 3D model based on user input, and wherein each region of interest corresponds to a position of one or more teeth of a dental arch on the 3D model,

[0293] selecting one or more combined scans based on the one or more selected regions of interest on the 3D model and the one or more selected labels, and

[0294] Displaying one or more combined scan information on a display unit of the intraoral scanning system.

[0295] 48. An intraoral scanning system according to any of items 2 and 39 to 47, wherein the display of the combined scan information comprises a combination of the combined scan information and surface information or fluorescence information.

[0296] 49. An intraoral scanning system according to item 48, wherein the combined scan information, surface information or fluorescence information corresponds to the same one or more teeth in the dental arch.

[0297] 50. An intraoral scanning system according to any of items 48 and 49, wherein surface information or fluorescence information related to the surface of one or more teeth of the dental arch is colored with one or more colors, and the combined scan information is colored with one or more colors unrelated to the one or more colors of the surface.

[0298] 51. An intraoral scanning system according to item 50, wherein the one or more processors are configured to select one or more colors of the surface and combine scan information based on user preferences or based on color machine learning output of a color machine learning unit of the system, the color machine learning unit being trained based on a training data set including user preferences of multiple users of the system.

[0299] 52. The intraoral scanning system according to any of items 30 to 35, wherein the hybrid scan information is configured to be displayed on a display unit of the intraoral scanning system.

[0300] 53. An intraoral scanning system according to item 52, wherein the displayed hybrid scanning information includes a combination of the hybrid scanning information and the surface information or the fluorescence information.

[0301] 54. The intraoral scanning system of item 52 or 53, wherein the one or more processors are configured to select the plurality of combined scan information to be displayed based on user input.

[0302] 55. The intraoral scanning system according to any of items 52 to 54, wherein the one or more processors are configured to add or remove one or more combination scan information to the plurality of combination scan information of the mixed scan information based on user input.

[0303] 56. An intraoral scanning system according to any of items 52 to 55, wherein the displayed mixed scanning information includes one or more colors representing surface information or fluorescence information, and the mixed scanning information is represented by one or more colors unrelated to the one or more colors representing surface information or fluorescence information.

[0304] 57. An intraoral scanning system according to item 56, wherein the one or more processors are configured to change the coloring of one or more colors of the mixed scan information and one or more colors of the surface information or fluorescence information based on user input.

[0305] 58. The intraoral scanning system according to any of items 52 to 57, wherein the one or more processors are configured to:

[0306] Displaying a three-dimensional (3D) model of the dental arch on a display unit of the intraoral scanning system;

[0307] Displaying a marker (viewing marker, cursor) on a portion of the 3D model of the dental arch on the display unit;

[0308] Changing the relative position between the marker and the 3D model of the dental arch based on input from a user input device of the intraoral scanning system;

[0309] identifying, from both the 3D model of the dental arch and the plurality of combined scans, two or more combined scans that approximate the relative angle and position of the marker relative to the 3D model of the dental arch, wherein each of the plurality of combined scans includes internal light information and visible light information captured at an angle and position; and

[0310] Displaying hybrid scan information including the identified two or more combined scan information, wherein the internal light information and the visible light information of the selected two or more combined scan information correspond to angles and positions that approximate the angles and positions of the marker relative to the 3D model of the dental arch.

[0311] 59. The intraoral scanning system according to any of items 52 to 57, wherein the one or more processors are configured to:

[0312] Displaying the mixed scan information including the plurality of combined scan information on a display unit of the system;

[0313] On the display unit, displaying a slider (view marker, cursor) next to the displayed hybrid scan information;

[0314] Changing the position of the slider based on user input from a user input device of the intraoral scanning system; and

[0315] Add or remove combined scan information to the hybrid scan information based on the position of the slider.

[0316] 60. The intraoral scanning system according to any of the preceding items, wherein the handheld intraoral scanning device is configured to emit light having different wavelengths during different time periods.

[0317] 61. The intraoral scanning system according to item 14, wherein the first set of time periods and the second set of time periods are arranged accordingly within the time frame.

[0318] 62. The intraoral scanning system according to item 61, wherein the time frame comprises a first repetition rate of the time periods of the first set of time periods and a second repetition rate of the time periods of the second set of time periods.

[0319] 63. An intraoral scanning system according to items 15 and 61, wherein the time frame comprises a third repetition rate of time periods of a third group of time periods.

[0320] 64. An intraoral scanning system according to item 62 and / or 63, wherein the first repetition rate, the second repetition rate and / or the third repetition rate are determined by the one or more processors based on a scanning mode, wherein the scanning mode is determined based on user input.

[0321] 65. The intraoral scanning system according to item 64, wherein the scanning mode is one of the following modes:

[0322] a first diagnostic mode, wherein the first repetition rate is greater than or equal to the second repetition rate;

[0323] a second diagnostic mode, wherein the first repetition rate and the third repetition rate are greater than or equal to the second repetition rate; and

[0324] • A first surface scanning mode, wherein the first repetition rate is less than the second repetition rate.

[0325] 66. An intraoral scanning system according to item 65, wherein the one or more processors are configured to switch between different scanning modes based on user input during a scanning process of the dental arch based on the user input.

[0326] 67. An intraoral scanning system according to any of the preceding items, comprising a wireless communication interface between a handheld intraoral scanning device and one of the one or more processors or a group of the one or more processors, and wherein visible light information is wirelessly transmitted at a first data rate and internal light information is wirelessly transmitted at a second data rate.

[0327] 68. An intraoral scanning system according to item 67, wherein the one or more processors are configured to change the first data rate and / or the second data rate according to the scanning mode.

[0328] 69. An intraoral scanning system according to any of items 67 and 68, wherein the first data rate is different from the second data rate.

[0329] 70. An intraoral scanning system according to any of items 1 to 68, wherein the visible light information and the internal light information are wirelessly transmitted at the same data rate.

[0330] 71. An intraoral scanning system according to any of the preceding items, wherein the wireless transmission of the visible light information and the internal light information is wirelessly transmitted in groups, wherein a group includes the visible light information and the corresponding internal light information.

[0331] 72. An intraoral scanning system according to any of the preceding items, wherein the wireless transmission of visible light information includes a first identifier, and the wireless transmission of internal light information includes a second identifier, and wherein the combined scan information includes a combination of internal structure information determined by the internal light information including the second identifier and the visible light information including the first identifier, and wherein the first identifier matches the second identifier.

[0332] 73. An intraoral scanning system according to any of the preceding items, wherein the visible light information and the internal light information are asynchronously wirelessly transmitted to a processor or a group of processors among the one or more processors.

[0333] 74. An intraoral scanning system according to any of items 1 to 72, wherein the visible light information and the internal light information are synchronously wirelessly transmitted to a processor or a group of processors among the one or more processors.

[0334] 75. An intraoral scanning system according to any of the preceding items, wherein the one or more processors are configured to select one or more modulation schemes for modulating visible light information and / or internal light information to be transmitted through the wireless network of the intraoral scanning system.

[0335] 76. The intraoral scanning system of item 75, wherein the one or more processors are configured to select one or more modulation schemes based on a scanning mode or a type of information to be transmitted over the wireless network.

[0336] 77. The intraoral scanning system according to any of items 75 and 76, wherein the one or more modulation schemes include the following modulation schemes:

[0337] MOK (M-ary Orthogonal Keying),

[0338] ACM (Automatic Coding and Modulation scheme),

[0339] MBOK (M-ary Biorthogonal Keying),

[0340] CCK (Complementary Code Keying),

[0341] CCSK (Cyclic Code Shift Keying),

[0342] PSK (Phase Shift Keying),

[0343] PPM (Pulse Position Modulation),

[0344] QAM (Quadrature Amplitude Modulation),

[0345] OCDM (Orthogonal Frequency Division Multiplexing) and

[0346] OFDM (Orthogonal Frequency Division Multiplexing).

[0347] 78. An intraoral scanning system according to any of the preceding items, comprising a user interface configured to receive user input.

[0348] 1A. An intraoral scanning system configured to provide combined scan information, the system comprising a handheld intraoral scanning device, the handheld intraoral scanning device comprising:

[0349] a projection unit configured to emit light at near infrared wavelengths, blue wavelengths, and white wavelengths onto at least one dental arch,

[0350] an image sensor unit configured to capture visible light information and internal light information from at least one dental arch caused by the light emitted by the projection unit, and

[0351] The system further includes one or more processors operably connected to the image sensor unit, the one or more processors being configured to:

[0352] Receives visible light information related to white and blue wavelengths and internal light information related to near-infrared wavelengths,

[0353] determining surface information in real time from the visible light information in order to generate or update a three-dimensional (3D) model of the dental arch using the surface information,

[0354] Determine the dental arch's fluorescence information from visible light information associated with blue wavelengths,

[0355] Determine the internal structure of the dental arch from this internal light information,

[0356] Determining combined scan information comprising a combination of the internal structure information and the fluorescence information.

[0357] 2A. The intraoral scanning system of item 1, wherein the fluorescence information comprises at least green fluorescence information.

[0358] 3A. The intraoral scanning system of item 2A, wherein the fluorescence information comprises at least red fluorescence information.

[0359] 4A. The intraoral scanning system according to any of these items, wherein the combined scan information comprises a difference between the internal structure information and the fluorescence information, or vice versa.

[0360] 5A. The intraoral scanning system according to any of these items, wherein the combined scan information comprises the sum of the internal structure information and the fluorescence information.

[0361] 6A. An intraoral scanning system according to items 2 and 3, wherein the one or more processors are configured to determine a first difference between the internal structure information and the green fluorescence information and a second difference between the internal structure information and the red fluorescence information, and wherein the combined scanning information includes the sum of the first difference and the second difference.

[0362] 7A. The intraoral scanning system according to items 2 and 3, wherein the combined scanning information includes the sum of the internal structure information, the green fluorescence information and the red fluorescence information.

[0363] project

[0364] 1B. An intraoral scanning system configured to provide combined scan information, the system comprising a handheld intraoral scanning device, the handheld intraoral scanning device comprising:

[0365] a projection unit configured to emit light at near infrared wavelengths and white wavelengths onto at least one dental arch,

[0366] an image sensor unit configured to capture visible light information and internal light information from at least the dental arch caused by the light emitted by the projection unit, and

[0367] The system further includes one or more processors operably connected to the image sensor unit, the one or more processors being configured to:

[0368] receiving the visible light information and the internal light information,

[0369] determining surface information in real time from the visible light information in order to generate or update a three-dimensional (3D) model of the dental arch using the surface information,

[0370] Determining internal structural information of the dental arch from this internal light information, and

[0371] Determining combined scan information comprising a combination of the internal structure information and the surface information.

[0372] 2B. The intraoral scanning system of item 1B, wherein the combined scan information comprises a difference between the internal structure information and the surface information, or vice versa.

[0373] 3B. An intraoral scanning system according to any of the preceding items, wherein the one or more processors are configured to determine a first type of restoration based on combined scanning information including a difference between the internal structure information and the surface information, and to determine a second type of restoration based on combined scanning information including a difference between the surface information and the internal structure information.

[0374] 4B. An intraoral scanning system according to Item 3B, wherein the one or more processors are configured to determine a plurality of combined scanning information, the plurality of combined scanning information comprising at least: combined scanning information including a difference between the internal structure information and the surface information; and second combined scanning information including a difference between the surface information and the internal structure information.

Claims

1. An intraoral scanning system configured to provide combined scan information, the system comprising a handheld intraoral scanning device, the handheld intraoral scanning device comprising: a projection unit configured to emit light having different wavelengths onto at least one dental arch during time periods, wherein the different wavelengths include near infrared wavelengths and visible wavelengths, an image sensor unit configured to capture visible light information and internal light information from the at least one dental arch caused by the visible wavelength and the near-infrared wavelength, respectively, and The system further comprises one or more processors operably connected to the image sensor unit, wherein the one or more processors are configured to: receiving the visible light information and the internal light information, determining surface information in real time from the visible light information so as to generate or update a three-dimensional (3D) model of the dental arch using the surface information, Determining internal structural information of the dental arch from the internal light information, and Determining combined scan information comprising a combination of the internal structure information and the visible light information, wherein the combination comprises a light intensity difference between the internal structure information and the visible light information.

2. The intraoral scanning system according to claim 1, wherein: The one or more processors are configured to determine fluorescence information of the dental arch from the visible light information.

3. The intraoral scanning system according to claim 1 or 2, wherein: The combined scanning information includes a difference between the internal structure information and the visible light information, or a difference between the internal structure information and the fluorescence information.

4. The intraoral scanning system according to claim 2, wherein: The fluorescence information includes green fluorescence information and / or red fluorescence information.

5. The intraoral scanning system according to claim 4, wherein: The one or more processors are configured to determine a first difference between the internal structure information and the green fluorescence information, and a second difference between the internal structure information and the red fluorescence information, and wherein the combined scan information comprises a sum of the first difference and the second difference.

6. The intraoral scanning system according to claim 4, wherein: The combined scanning information includes the sum of the internal structure information, the green fluorescence information, and the red fluorescence information.

7. The intraoral scanning system according to any one of claims 1 or 2, wherein: The combined scan information comprises the difference between the internal structure information and the surface information, or vice versa.

8. An intraoral scanning system according to any one of the preceding claims, wherein: The combination corresponds to a light intensity difference between the light intensity of the internal structure information and the light intensity of the visible light information, or vice versa, or a light intensity sum between the light intensity of the internal structure information and the light intensity of the visible light information.

9. An intraoral scanning system according to any one of the preceding claims, wherein: The internal structure information and the visible light information are weighted in the combined scan information, wherein the internal structure information is weighted by a first weighting coefficient and the visible light information is weighted by a second weighting coefficient.

10. The intraoral scanning system according to claim 9, wherein: The one or more processors are configured to change the first weighting coefficient and the second weighting coefficient, wherein the change corresponds to a change in brightness, contrast, and / or transparency of the internal structure information and the visible light information.

11. An intraoral scanning system according to any one of the preceding claims, wherein: The combination includes.

12. An intraoral scanning system according to any one of the preceding claims, wherein: The one or more processors are configured to determine a plurality of combined scan information including the combined scan information and second combined scan information, wherein the combined scan information is different from the second combined scan information.

13. The intraoral scanning system according to claim 12, wherein: Each of the multiple combined scanning information includes a different enhanced internal structure, and wherein the one or more processors are configured to label each of the multiple combined scanning information, and the label indicates the enhanced internal structure and / or enhanced texture information of the combined scanning information in the multiple combined scanning information.

14. The intraoral scanning system according to claim 11, wherein: The enhanced internal structure corresponds to the dental condition of the teeth of the patient's dental arch, wherein the dental condition corresponds to cracks, caries lesions, dentin-enamel junctions, voids, plaque, and restorations.

15. An intraoral scanning system according to any one of the preceding claims, wherein: The projection unit includes one or more first light sources and at least one or more second light sources, wherein the one or more first light sources are configured to emit light at a near-infrared wavelength during a first group of time periods, and the one or more second light sources are configured to emit light at a visible wavelength during a second group of time periods, and wherein the visible light information includes information corresponding to the surface reflection of the dental arch caused by the first visible wavelength and captured by the image sensor unit, or the visible light information includes information corresponding to the fluorescence information of the dental arch caused by the second visible wavelength and captured by the image sensor unit.

16. The intraoral scanning system according to any one of claims 1 to 14, wherein: The projection unit includes one or more first light sources, at least one or more second light sources and at least one or more third light sources, wherein the one or more first light sources are configured to emit light at a near-infrared wavelength during a first group of time periods, the one or more second light sources are configured to emit light at a first visible wavelength during a second group of time periods, and the one or more third light sources are configured to emit light at a second visible wavelength during a third group of time periods, wherein the first visible wavelength is different from the second visible wavelength, and wherein the visible light information includes information corresponding to the surface reflection of the dental arch caused by the first visible wavelength and captured by the image sensor unit, and the visible light information includes information corresponding to the fluorescence information of the dental arch caused by the second visible wavelength and captured by the image sensor unit.

17. The intraoral scanning system according to claim 15 and / or 16, wherein: The one or more processors are configured to determine surface information provided by the surface reflection of the first visible wavelength, and the combined scan information includes a combination of the internal structure information and visible light information including the surface reflection of the first visible wavelength, and / or, the combined scan information includes a combination of the internal structure information and visible light information including fluorescence information of the second visible wavelength.

Images