Device for designing dental prostheses

Abstract

To provide a method for manufacturing a dental prosthesis that has the natural appearance and high chromatic and geometric accuracy, and a computer device and a computer program for designing the dental prosthesis.SOLUTION: A method for designing a dental prosthesis comprises the steps of: measuring a target dataset that reproduces the optical characteristic and / or geometric shape of a natural tooth with the natural tooth as a base (S101); creating a digital tooth model including an internal architecture (S102); rendering the digital tooth model on the basis of the internal architecture for creating the actual dataset that reproduces the optical characteristic and / or geometric shape of the digital tooth model (S103); calculating a difference between the target dataset and the actual dataset (S104); and acquiring a small difference between the measured target dataset and the actual dataset of the digital tooth model that has been rendered again by repeatedly changing the digital tooth model (S105).SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a method for designing a dental prosthesis, a computer device for designing a dental prosthesis, and a computer program for the computer device. [Background technology]

[0002] Color and translucency are often issues when manufacturing dental prostheses, because they are extremely difficult to determine and because the structure of the prosthesis, with its different layers and materials, affects the final appearance. Furthermore, color determination is currently often based on the dental technician's experience or on estimation through objective color comparison using a color key. Today, dental prostheses, especially individual prostheses, are increasingly being manufactured by dentists. Accurate color selection is crucial during manufacturing, as patients may sometimes wait in the dental clinic for their prosthesis to be manufactured.

[0003] Patent document 1 discloses that the appearance of a virtual tooth can be compared by a user, for example, on a calibrated screen with images of adjacent teeth, thereby obtaining a realistic impression. If the result is not satisfactory, for example, the layer thickness or translucency can be adjusted. However, there is always some imprecision when the user makes an optical comparison on a screen. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] European Patent No. 2486892 (B1) Summary of the Invention [Problem to be solved by the invention]

[0005] The technical problem of the present invention is therefore to produce a dental prosthesis that has a natural appearance and high color and geometric accuracy. [Means for solving the problem]

[0006] The above-mentioned problem is solved by the subject matter of the independent claims. Technically preferred embodiments are defined by the dependent claims, the description and the accompanying drawings.

[0007] According to a first aspect, the above technical problem is solved by a method for designing a dental prosthesis, comprising the steps of measuring a target dataset that reproduces the optical properties and / or geometry of a natural tooth based on the natural tooth; creating a digital tooth model including an internal architecture; rendering the digital tooth model based on the internal architecture to create a real dataset that reproduces the optical properties and / or geometry of the digital tooth model; calculating the difference between the target dataset and the real dataset; and iteratively modifying the digital tooth model to obtain smaller differences between the measured target dataset and the real dataset of the re-rendered digital tooth model.

[0008] The internal architecture includes the spatial configuration and the materials used for that configuration. Because the optical properties and spatial configuration of the materials used are known, an optical real data set that reproduces the optical appearance of the digital tooth model can be rendered from the digital tooth model. By automatically calculating the differences between the target data set and the real data set and adjusting the internal architecture and materials used derived therefrom, a dental prosthesis with an appearance corresponding to the measured appearance of the natural tooth can be manufactured. After the dental prosthesis is installed, the artificial tooth is integrated so harmoniously that it is indistinguishable from the surrounding natural teeth under various lighting conditions. The layering of the dental prosthesis can be realistically simulated before manufacturing depending on the materials used, thereby ensuring the user achieves the accurate results they expect.

[0009] The rendering takes into account the optical parameters of the materials used, which cannot be reproduced or recognized in the image displayed on the screen. Specific material properties and the effects of neighboring teeth, gums, and / or various lighting conditions can also be taken into account. This method therefore does not rely on human perception. Modifications to the digital tooth model can be carried out, for example, by replacing it with a material with different optical properties or by changing the placement or layer thickness of materials in the internal architecture.

[0010] According to a technically preferred embodiment of this method, the difference is calculated based on the Euclidean distance between the target data set and the actual data set. This provides a technical advantage, for example, in that the degree of difference can be accurately determined with little effort. If the numerical values ​​of the target data set are special color values, such as clinical test values, that do not exist as tooth colors in tooth color keys, a comparison can be made with high accuracy based on a comparison between clinical actual values ​​and clinical target values.

[0011] According to yet another technically preferred embodiment of the method, the difference is calculated based on the spectral distance between the target data set and the actual data set, thereby achieving the technical advantage that, for example, an accurate color comparison is performed between the target data set and the actual data set.

[0012] According to another technically preferred embodiment of the method, the target data set comprises data on two-dimensional or three-dimensional images of natural teeth, data on imaging angles relative to the teeth, data on tooth color information, data on tooth color spectrum, and / or data on tooth geometry, thereby achieving technical advantages, e.g., that highly suitable data can be used for the reconstruction and the difference calculation.

[0013] According to another technically preferred embodiment of the method, the target data set is measured by a digital camera, a 3D scanner, a 3D camera system, a spectrometer or a digitized color key, thereby achieving the technical advantage that the target data set can be obtained in a simple and fast manner without having to take environmental requirements into account, for example, since the environmental requirements can be calculated later by a computer program.

[0014] According to another technically preferred embodiment of the method, the target data set includes the optical properties of the remaining teeth. In this case, data of the remaining teeth can also be measured. The data also includes the optical properties and / or the geometric shape of the remaining teeth. This achieves the technical advantage, for example, that a proper and precise adjustment of the dental prosthesis can be performed based on the remaining tooth structure.

[0015] According to another technically preferred embodiment of the method, the digital tooth model is rendered based on the optical properties of the remaining teeth, the geometry of the remaining teeth, the surrounding adjacent teeth, the oral situation, the gums or gum color considerations, and / or the adhesive used to fix the dental prosthesis to the remaining teeth. The rendering is performed in correlation with the optical properties of the dental prosthesis. This also achieves technical advantages, such as a proper and precise adjustment of the dental prosthesis based on the remaining tooth structure.

[0016] According to another technically preferred embodiment of the method, the step of creating a digital tooth model comprises capturing, calculating and / or determining a tooth model having a given internal architecture. The capturing step can precede the creating step, thereby achieving technical advantages such as speeding up the method and allowing to select from multiple existing digital tooth models.

[0017] According to another technically preferred embodiment of the method, the digital tooth model is rendered at an angle corresponding to the imaging angle and / or given lighting requirements for measuring the tooth, thereby achieving technical advantages such as a better comparison between the target data set and the actual data set and reduced, i.e. faster, calculation effort for rendering the remaining teeth or the dental prosthesis on the preparation into an appropriate projection.

[0018] According to another technically preferred embodiment of the method, the digital tooth model is modified by changing the material allocation to the sub-volumes, thereby achieving the technical advantage that, for example, larger deviations can be compensated for, and thus a more natural configuration and appearance of the dental prosthesis can be achieved.

[0019] According to another technically preferred embodiment of the method, the digital tooth model is modified by modifying sub-volumes while maintaining the outer geometry, which also achieves the technical advantage that, for example, smaller deviations can be compensated for without changing material, resulting in a natural configuration and appearance of the dental prosthesis.

[0020] According to another technically preferred embodiment of the method, a comparison between functional requirements, such as a given minimum wall thickness, and cosmetic requirements is determined and optionally presented to the user for evaluation.

[0021] According to another technically preferred embodiment of the method, a dental prosthesis is manufactured based on the actual data set, which also achieves the technical advantage that, for example, the dental prosthesis can be manufactured automatically and a proper color reproduction corresponding to the target data set is achieved by prior simulation.

[0022] According to another technically preferred embodiment of the method, the dental prosthesis is manufactured using a multi-material three-dimensional printer or a milling machine. Manufacturing the dental prosthesis can also include printing the dental prosthesis in a stereolithography process and subsequent sintering. When using a pressing technique with a color-graded blank, the orientation and position of the prosthesis in the blank can be individually and specifically determined. Both of the above-mentioned manufacturing methods offer technical advantages, such as the ability to rapidly manufacture natural-looking dental prostheses.

[0023] According to another technically preferred embodiment of the method, the dental prosthesis is manufactured from multiple or selectively colored materials using an additive manufacturing method. The manufacturing of the dental prosthesis can be performed by additive manufacturing steps in which multiple materials are assigned to sub-volumes of a given dental prosthesis and selectively applied in space, or in which a single-color material is applied in layers, with individual layers being selectively colored or discolored. This additive manufacturing method achieves technical advantages, such as the ability to rapidly manufacture natural-looking dental prostheses according to the settings of a digital target data set.

[0024] According to a second aspect, the aforementioned technical problem is solved by a computerized device for designing a dental prosthesis using a sensor for measuring a target data set based on natural teeth, which is suitable for carrying out the method according to the first aspect described above, thereby achieving the same technical advantages as those of the first aspect described above.

[0025] According to a third aspect, the aforementioned technical problem is solved by a computer program comprising instructions for operating a computer device according to the second aspect to perform the method steps according to the first aspect.

[0026] Various embodiments of the present invention are illustrated in the accompanying drawings and will be described in more detail in the following description. [Brief explanation of the drawings]

[0027] [Figure 1] FIG. 1 is a schematic diagram illustrating a computer system for designing a dental prosthesis. [Figure 2] FIG. 1 is a schematic illustration showing the differences between the target data set and the actual data set. [Figure 3] FIG. 1 is a schematic illustration of the calculation of the discrepancy between the target data set and the actual data set. [Figure 4] FIG. 1 is a block diagram illustrating a method for designing a dental prosthesis. DETAILED DESCRIPTION OF THE INVENTION

[0028] 1 schematically illustrates a computer device 200 for designing a dental prosthesis 207. The computer device 200 comprises a sensor 203 for measuring a target data set based on a natural tooth 205. The sensor 203 can measure data related to the imaging angle of the tooth 205, data related to color information of the tooth 205, data related to the color spectrum of the tooth 205, data related to the translucency of the tooth 205, and / or data related to geometric information of the tooth 205. The sensor 203 thereby provides data that is embedded in the target data set for subsequent calculations.

[0029] The sensor 203 may be, for example, an electronic digital camera, a 3D scanner with color detection, a TOF camera using the Time of Flight method, or a camera capable of measuring distances using line light and triangulation. The sensor 203 measures color and geometric information of the tooth 205, such as the color distribution, translucency, and / or shape of the tooth 205. The sensor 203 for color detection can be different from the one for geometry detection. For example, color detection can be performed by a camera, and the geometry can be detected by a separate scanner. However, it is also possible to create an analog impression, which is then digitized by a Lab scanner, for example.

[0030] In general, the sensor 203 can be any device suitable for detecting color, translucency, and / or geometric information of the teeth 205, which subsequently serves as the basis for the target data set.

[0031] The sensor 203 can measure, for example, geometric and color information based on the adjacent tooth 205, which then serves as a template for manufacturing the adjacent dental prosthesis 207. In addition, the sensor 203 can be configured to determine the imaging angle of the projection relative to the tooth 205. The sensor 203 can be part of a mobile device, for example, a smartphone or a tablet. The sensor 203 can perform color or translucency measurements of the adjacent tooth 205, for example, based on the color space of natural teeth. In addition, the sensor 203 can measure the optical properties and geometry of the remaining tooth 209, for example, a stump, on which the dental prosthesis 207 will be mounted.

[0032] The computer device 200 further comprises a generation unit 211 for generating a digital tooth model with an internal architecture, which reproduces the internal structure of the digital tooth model, and which can include a combination of at least two dental prosthesis materials with different optical and / or physical properties.

[0033] The different dental prosthesis materials can be arranged in voxels in the case of additive manufacturing methods or in layers in the case of layered raw materials. In the case of monochromatic materials, each layer can be selectively colored. The internal architecture of the tooth model not only contains three-dimensional information, but also information about the physical-optical properties of the prosthesis, such as the adsorption or diffusion coefficients of the materials used.

[0034] The digital tooth model can be formed from an architecture consisting of different sub-volumes (shells), each of which can be assigned corresponding optical and / or physical material parameters, so that the materials and semi-finished products used are optically characterized and parameterized in advance.

[0035] The generation unit 211 can, for example, model both the external shape and the internal architecture of the digital tooth model in a CAD process. Therefore, the digital tooth model of the tooth to be restored can first be loaded from a digital tooth library as a 3D tooth model with a given internal architecture and then adapted to a given patient situation. The 3D tooth model is based on an idealized 3D structure whose appearance is known, i.e., pre-calculated. By automatically assigning the target data set to a defined color space, the system pre-selects material combinations for the real data set of the prosthesis and presents them to the user.

[0036] The computer arrangement 200 further comprises a rendering unit 213, which optically simulates the optical appearance of the biomimetic dental prosthesis, i.e. the real situation, based on the generated digital tooth model, taking into account not only the internal architecture of the tooth but also the optical and, if necessary, mechanical properties of the materials used.

[0037] For this purpose, in addition to the three-dimensional geometric information, the optical parameters and / or physical properties for all layers or sub-volumes of the different materials of the digital tooth model are incorporated into the simulation software of the rendering unit 213. The rendering of the digital tooth model can also be performed taking into account the optical properties of the remaining teeth 205 and the adhesives used to fix the dental prosthesis 207, the adjacent teeth, the gum color, and / or the oral situation.

[0038] If the imaging angle of the target data set is known, the rendering of the digital tooth model can be performed from a projection corresponding to the detected imaging, whereby a two-dimensional image of the rendered digital tooth model can be generated as the real data set from a projection corresponding to the projection during measurement of the target data set. By superimposing the two-dimensional images of the target data set and the real data set in the same projection, the difference between the target data set and the real data set can be calculated.

[0039] The rendering simulates the optical appearance of the dental prosthesis 207, taking into account remaining teeth and adhesives as needed, to generate an actual data set containing the same parameters as the target data set, thereby allowing the difference to be calculated. The computer device 200 calculates the numerical difference ΔE between the target data set and the actual data set. S,I The difference ΔE S,I defines a numerical value that quantifies the difference between the target data set and the real data set. For example, the color and translucency scheme of the target data set can be used to perform map matching of the real data set, thereby obtaining the difference ΔE S,I can be obtained.

[0040] Difference ΔE S,I can be calculated based on the Euclidean or spectral distance between the target and real data sets.

[0041] Smaller discrepancies ΔE between the measured target dataset and the real dataset of the re-rendered digital tooth model S,I In order to obtain the above, the computer arrangement 200 additionally comprises a modification unit 217 for automatically and iteratively modifying the digital tooth model. Thus, the modification unit 217 can automatically modify, for example, layer thicknesses or material allocations of the tooth model, thus modifying the optical properties of the target data set, thereby obtaining a realistic appearance.

[0042] For example, iterative modifications of the digital tooth model can be performed by changing the material allocation between sub-volumes, such as the incisal and dentin regions, while maintaining the outer geometry of the tooth. The material and optical parameters are then assigned to the modified 3D tooth model, including the preparation and cement layers, and re-rendered, and the results are compared to the target dataset, and the difference ΔE between the real and target datasets is calculated. S,I is calculated. Dental materials available come in a comprehensive color palette and with various degrees of translucency.

[0043] From the modified tooth model, the real dataset is again rendered, and the difference ΔE between the real dataset and the target dataset is calculated. S,I is calculated.

[0044] Calculated difference ΔE S,I For example, if exceeds a given value, the material or material combination of the dental prosthesis 207 can be adjusted while maintaining the outer geometry. S,I If falls below a given value, fine-tuning is performed by modifying the subvolumes of the internal architecture or by topographical modification of the interface between the incisal edge and the dentin while maintaining the external geometry, whereby the prosthesis can also be characterized by the topographical modification of the interface.

[0045] Given the difference ΔE S,I When the lower value of the difference ΔE is reached, the design of the prosthesis 207 and the material selection for the digital tooth model are completed, and the dental prosthesis 207 can therefore be manufactured. S,I If lies below a given value, the digital tooth model replicates the final dental prosthesis 207.

[0046] Instead of implementing thresholds, both adjustment methods, material and interface adjustment, can be applied simultaneously in parallel.

[0047] It can be manufactured using multi-material three-dimensional printing or milling from a blank by automated manufacturing equipment 219. After placement of the dental prosthesis 207 in the patient's mouth, the optical appearance of the biomimetic dental prosthesis best approximates a natural appearance.

[0048] The computer device 200 allows the dental prosthesis 207 to be manufactured as naturally as possible (biomimetic) and visually optimally integrated into the patient's oral environment.

[0049] The color and aesthetic evaluation and selection of the materials and dyes used is not performed subjectively by the user, but objectively and reproducibly by a calibrated automated process, which always follows the rules. The optical parameters of the materials used are clearly defined, allowing for a realistic simulation and rendering of the optical interactions of the materials used, the preparation, the cement layer, the dentin and incisal areas, and the oral situation (red and white aesthetics).

[0050] This allows for a target / actual comparison that allows iterative adjustment of the internal structure or architecture of the dental prosthesis 207. The renderings can suggest to the user suitable colors, materials, semi-finished products, and / or manufacturing methods for achieving a cosmetically optimal biomimetic dental prosthesis 207 quality. This method provides a dental prosthesis 207 that is ideally adapted to the patient's existing oral condition. The finished and applied dental prosthesis 207 is integrated into the overall aesthetically optimal picture, regardless of the user's subjective experience in selecting materials or semi-finished products according to a color key. Experience can be taken into account or integrated into the software, thereby benefiting less experienced dental technicians. This is the case, for example, with regard to the design of the tooth's internal architecture or staining techniques. Furthermore, the user can be offered the option of personal preferences (e.g., painting according to a specific scheme) or individual differences can be taken into account (gloss level).

[0051] Figure 2 shows the difference ΔE between the target dataset DS-S and the real dataset DS-I. S,I is shown schematically. A target data set DS-S is obtained based on measurements of the tooth 205 by a sensor 203. A digitally generated tooth model 221 contains data on the spatial geometry of the dental prosthesis 207 and the assigned materials for manufacturing the dental prosthesis 207. The optical and physical properties required for rendering are known in the rendering software. They can be taken from a parameter table to which new materials are constantly added.

[0052] A rendering of the tooth model 221 is performed to obtain a real data set DS-I from the tooth model 211, taking into account the spatial geometry of the dental prosthesis 207 and the optical and physical properties of the various materials present, including possibly adhesives and tooth forms.

[0053] The propagation of light within the tooth model 221 can be described by Maxwell's equations. The rendering uses, for example, the radiative transfer equation (RTE), whereby the propagation medium is described by an absorption coefficient, a scattering coefficient, a refractive index, and a scattering phase function. The digital tooth model 221 includes, for example, data on the spatial geometry and internal architecture of the dental prosthesis 207, as well as the absorption coefficient, scattering coefficient, refractive index, and scattering phase function of each material in the architecture.

[0054] The scattering phase function can be solved numerically with any required accuracy by Monte Carlo simulation (ray tracing) using the above-mentioned parameters during rendering based on the tooth model 221, in which a large number of photons propagate on random paths through the tooth model. As a result, the rendering allows the calculation of a real data set DS-I for the appearance of the dental prosthesis 207, taking into account the materials used and the external and internal architecture of the tooth model 221. This calculated real data set DS-I can then be compared with a target data set DS-S obtained based on the adjacent teeth. To simplify the comparison, it can be performed on two-dimensional derivatives (two-dimensional images). The difference ΔE between the real and target data sets S,I A numerical value is then calculated as a measure of the difference ΔE S,I The digital tooth model is modified until is minimized or is below a given threshold.

[0055] Figure 3 shows the difference ΔE between the target dataset DS-S and the real dataset DS-I. S,I The calculation of is shown schematically. For example, dataset DS-S contains a representation of a tooth 205 in a given projection, whereas dataset DS-I rendered from a tooth model contains a representation of the tooth model in the same projection. Images from both target dataset DS-S and actual dataset DS-I are scaled to the same size and placed side by side. The Euclidean difference between target dataset DS-S and actual dataset DS-I is calculated by computing the difference in color values ​​of pixels along comparison line 223, e.g., Lab(L * a * b * ) color space by accumulating. The comparison line 223 can be arbitrarily shifted by simultaneously moving each half of the tooth. However, in general, the comparison line 223 can have other trajectories. The comparison can be performed at the pixel level as a minimum resolution.

[0056]

number

[0057] The greater the difference in color change along the comparison line 223, the greater the numerical difference ΔE S,I When the target data set DS-S and the actual data set DS-I are perfectly color matched, the difference ΔE S,I However, in general, other methods, such as those based on spectral information, can be used to calculate the difference ΔE S,I It can also be used to calculate

[0058] FIG. 4 shows a block diagram of a method for designing a dental prosthesis 207. In a first step S101, a target data set DS-S that reproduces the optical properties, such as color, coloration, and translucency, and / or geometry of the natural tooth 205 is measured based on the natural tooth 205. Ideally, the measurement of the target data set DS-S can be performed on a tooth adjacent to the tooth to be prosthetically restored as a template. This achieves the technical advantage of allowing the actual data set DS-I of the dental prosthesis 207 to be adapted as accurately and color-matched to the oral situation as possible. In step S102, a digital tooth model 221 is formed with an internal architecture, i.e., derived from an ideal tooth model in a tooth library, which serves as the basis for the subsequent process. In step S103, the materials used and the optical and physical parameters of the required internal architecture are assigned to the digital tooth model 221, thereby rendering the digital tooth model 221 and creating the actual data set DS-I that is used for the target / actual comparison in the next stage.

[0059] Then, in step S104, the difference ΔE between the target data set DS-S and the actual data set DS-I S,I In step S105, the difference ΔE between the measured target data set DS-S and the generated actual data set DS-I is calculated. S,IThe digital tooth model 221 is modified by allocating different materials and / or changing the internal architecture so that the difference ΔE between the actual data set DS-I and the target data set DS-S is smaller. S,I Steps S103 to S105 are performed iteratively until a minimum value or a given convergence interval is reached (e.g., when making a tradeoff to maintain a minimum wall thickness, limit the availability of dental materials that are becoming less common, etc.). This method achieves the technical advantage of being able to manufacture a dental prosthesis 207 with a biomimetic appearance that corresponds to that of the measured natural tooth 205. In addition, it achieves the advantage of being able to cover more appearance shapes with fewer material items in the future.

[0060] The difference ΔE between the actual data set DS-I and the target data set DS-S by the iterative formation method of the biomimetic dental prosthesis 207 S,I is minimized. This applies, for example, to patient-specific color measurement, preparation, modeling, simulation, and production of an aesthetic dental prosthesis 207. It involves an iterative, closed-loop digital process in which the modeling and simulation of the dental prosthesis 207 approximates as closely as possible the natural appearance in the patient's mouth. The automatic comparison according to the natural appearance eliminates the need for various color keys or subjective comparison of images.

[0061] This method for designing a dental prosthesis 207 involves an iterative, closed digital process of modeling and simulating the dental prosthesis 207 to approximate as closely as possible the natural appearance in the patient's mouth. Because the optical parameters of the materials used are known and taken into account during rendering, the optical influences of various three-dimensional layers, such as the preparation, cement layer, dentin, and incisal region, can be optically realistically simulated for the first time, resulting in a more realistic appearance of the installed dental prosthesis 207. By using materials with known optical and physical properties (optically calibrated materials), the user perceives the biomimetic dental prosthesis 207 as realistic.

[0062] This method allows for the construction of biomimetic, i.e., highly natural, tooth-like, layered dental prostheses 207 to be realized through digital manufacturing processes such as multi-material milling or 3D printing. The target / actual color information can also be used for individual, selective coloring of zirconium dioxide bleaching agents by infiltration. This method falls within the comprehensive digital workflow for indirect dental prostheses and forms the basis for the implementation of cosmetic dentistry, including multi-material 3D printing.

[0063] All of the features described and illustrated in relation to individual embodiments of the invention can also be the subject of the invention in various combinations, whereby simultaneous advantageous results are achieved.

[0064] All method steps may be performed using apparatus suitable for performing each method step. All functions performed by the feature of interest may be method steps in this method.

[0065] The scope of protection of the present invention is defined only by the appended claims and is not limited by the features described or shown in the description.

Claims

1. 1. An apparatus for designing a dental prosthesis (207) using a computer device, comprising: measuring (S101) a target data set (DS-S) based on a natural tooth (205) that reproduces the optical properties and / or geometric shape of said natural tooth (205); Designing a digital tooth model (221) with a predetermined internal configuration (S102); Rendering (S103) the digital tooth model (221) based on the internal configuration to create a real data set (DS-I) that reproduces the optical properties and / or geometry of the digital tooth model (221); The deviation (ΔE Ｓ , Ｉ ) is calculated (S104), By iteratively modifying the digital tooth model (221), the deviation (ΔE) is calculated based on the Euclidean distance between the target data set (DS-S) and the actual data set (DS-I) or based on the spectral distance between the target data set (DS-S) and the actual data set (DS-I). Ｓ , Ｉ and rendering the digital tooth model (221) at an angle corresponding to the imaging angle and / or given lighting requirements when measuring the natural tooth (205).

2. The device described in claim 1, wherein the target dataset (DS-S) includes data regarding two-dimensional or three-dimensional images of the natural tooth (205), data regarding the imaging angle relative to the natural tooth (205), data regarding color information of the natural tooth (205), data regarding the color spectrum of the natural tooth (205), and / or data regarding geometric information of the natural tooth (205).

3. 3. The apparatus according to claim 1 or claim 2, wherein the target data set (DS-S) is measured by a digital camera, a 3D scanner, a 3D camera system, a spectrometer, or a digitized color key.

4. An apparatus described in any one of claims 1 to 3, wherein the target data set (DS-S) includes optical characteristics of the remaining teeth (209).

5. The device described in claim 4, wherein the digital tooth model (221) is rendered based on consideration of the optical properties of the remaining tooth (209), the geometric shape of the remaining tooth, surrounding adjacent teeth, oral conditions, gum or gum color, and / or adhesives used to fix the dental prosthesis (207) to the remaining tooth (209).

6. An apparatus described in any one of claims 1 to 5, wherein the step of creating the digital tooth model (221) includes a step of capturing, calculating, and / or determining the digital tooth model (221) having a given internal configuration.

7. The apparatus of any one of claims 1 to 6, wherein the digital tooth model (221) is modified by changing material allocation to sub-volumes.

8. The apparatus of any one of claims 1 to 7, wherein the digital tooth model (221) is modified by modifying the sub-volumes while preserving the outer geometry.

9. An apparatus described in any one of claims 1 to 8, wherein the dental prosthesis (207) is manufactured based on the actual data set (DS-I).

10. An apparatus as described in claim 9, wherein the manufacturing of the dental prosthesis (207) is carried out using a multi-material 3D printing device or a milling machine.

11. A computer device (200) for designing the dental prosthesis (207), having a sensor (203) for measuring the target data set (DS-S) based on the natural teeth (205), and suitable for carrying out the steps of any one of claims 1 to 10.

12. A computer program comprising instructions for causing a computer device according to claim 11 to perform the steps according to any one of claims 1 to 10.

Images