Method of Manufacturing a Dental Component

Abstract

The present invention relates to a method of manufacturing a dental component, in particular a dental prosthesis or a partial dental prosthesis, by means of a dental furnace, comprising the following steps: (i) producing a model of the dental component; (ii) embedding the model in an investment material; (iii) removing the model from the investment material, in particular by heating or burning out, to obtain a negative mold of the model;

(iv) inserting a raw material required for manufacturing the dental component into the negative mold; (v) producing the dental component in the negative mold; and (vi) deflasking the dental component in an at least partly automated manner, in particular by means of a stripping manufacturing process, on the basis of a virtual model of the dental component.

Claims

1. A method of manufacturing a dental component, in particular a dental prosthesis or a partial dental prosthesis, comprising the following steps: (i) producing a model of the dental component; (ii) embedding the model in an investment material; (iii) removing the model from the investment material, in particular by heating or burning out, to obtain a negative mold of the model; (iv) inserting a raw material required for manufacturing the dental component into the negative mold; (v) producing the dental component in the negative mold; and (vi) deflasking the dental component in an at least partly automated manner, in particular by means of a stripping manufacturing process, on the basis of a virtual model of the dental component.

2. A method in accordance with claim 1, characterized in that the virtual model is based on a 3D scan of the model and/or on a tomography of the negative mold; and/or in that the virtual model is based on a digital model of the dental component that was produced with the aid of virtual data of a dentition of a patient or of a part thereof.

3. A method in accordance with claim 2, characterized in that the virtual data of a dentition of a patient or of a part thereof are generated on the basis of an interoral scan and/or of a scan of a negative impression of a dentition of a patient or of a part thereof.

4. A method in accordance with at least one of the preceding claims, characterized in that a deflasking device for deflasking the dental component is provided and comprises a control unit that controls the deflasking device on the basis of the virtual model.

5. A method in accordance with at least one of the preceding claims, characterized in that a desired/actual comparison by means of the virtual model and data of a tomography of the negative mold is performed and the automated deflasking is adapted on the basis of the desired/actual comparison.

6. A method in accordance with at least one of the preceding claims, characterized in that the stripping manufacturing process comprises a compressed air blasting using a blasting means, and/or a water blasting, and/or a milling.

7. A method in accordance with at least one of the preceding claims, characterized in that a removal rate or a speed of the deflasking is adjustable, in particular automatically in dependence on progress of the deflasking.

8. A method in accordance with claim 7, characterized in that the negative mold is removed at a lower removal rate or a lower speed in the vicinity of the dental component than at a greater distance from the dental component.

9. A method in accordance with claim 4, characterized in that the negative mold has at least one means for—virtually—defining a model coordinate system relative to a coordinate system of the deflasking device, by which means the position and/or alignment of the dental component in the negative mold can be determined with respect to the deflasking device; and/or in that the negative mold and/or the deflasking device has/have at least one alignment means, in particular at least one optical marking and/or one mechanical coding, by which alignment means an exact alignment of the negative mold in the deflasking device can be defined.

10. A method in accordance with at least one of the preceding claims, characterized in that the model of the dental component is manufactured by means of additive manufacturing, in particular by means of 3D printing.

11. A method in accordance with at least one of the preceding claims, characterized in that the model of the dental component is produced on the basis of the virtual model.

12. A system for manufacturing a dental component (10), in particular a dental prosthesis or a partial dental prosthesis, comprising: a deflasking device (50, 160) for an at least partly automated removal of the dental component (10) from a negative mold (20) on the basis of a virtual model (14); and a control device (100), with the deflasking device (50, 160) being connectable or connected to the control device (100) to receive control data (162) from the control device (100), in particular with the deflasking device (50, 160) working by means of a stripping manufacturing process such as compressed air blasting, and/or water blasting, and/or milling.

13. A system in accordance with claim 12, characterized in that the system additionally comprises a programmable dental furnace (12, 150), with the programmable dental furnace (12, 150) being connectable or connected to the control device (100), in particular with the control device (100) being configured and adapted to automatically select a program (152) for operating the dental furnace (12, 150) and/or to automatically prepare such a program and/or to automatically suggest such a program on the basis of the virtual model (14) of the dental component (10), in particular with the control device (100) being configured and adapted to directly or indirectly control the dental furnace (12, 150).

14. A system in accordance with claim 12, characterized in that the system additionally comprises a raw data acquisition device (110), in particular an optical scanner (40), for intraorally scanning (26) a dentition (42) of a patient or a part thereof and/or for scanning a negative impression of a dentition (42) of a patient or a part thereof and/or for scanning the model (16) of the dental component (10).

15. A system in accordance with claims 12 to 14, characterized in that the control device (100) is configured and adapted to receive the virtual model (14, 122) and/or to prepare the virtual model (14, 122) on the basis of data (112) of at least one scan.

16. A system in accordance with at least one of the claims 12 to 15, characterized in that the system additionally comprises a model manufacturing apparatus (130) for the additive manufacturing of a model (16) on the basis of the virtual model (14, 122), in particular with the model manufacturing apparatus (130) being connectable or connected to the control device (100) to receive control data from the control device (100).

17. A system in accordance with at least one of the claims 12 to 16, characterized in that the system additionally comprises a programmable furnace (12A, 140) for removing a model (16) from an investment material (18), with the furnace (12A, 140) being connectable or connected to the control device (100) to receive control data (142) from the control device (100), in particular with the control device (100) being configured and adapted to automatically select at least one process parameter (142) for operating the furnace (12A, 140) and/or to automatically prepare such a process parameter and/or to automatically suggest such a process parameter on the basis of the virtual model (14, 122) of the dental component (10).

18. A system in accordance with at least one of the claims 12 to 17, characterized in that a dental furnace (12) has a pressing device (48) by means of which a raw material (22) can be inserted into a negative mold (20) on the application of a pressing force and/or by means of which the dental component (10) can be produced or fired on the application of a pressing force.

19. A system in accordance with at least one of the claims 12 to 18, characterized in that the raw data acquisition device (110, 40) and/or the model manufacturing apparatus (130) and/or the programmable furnace (12A) and/or the dental furnace (12) and/or the deflasking device (50, 160) has/have a control unit that is separate from the control device (100) and that is connectable and/or connected to the control device (100), in particular with the control device (100) providing a higher-ranking control.

Description

[0056] The method in accordance with the invention and the system in accordance with the invention will be described purely by way of example in the following with respect to an advantageous embodiment and to the Figures enclosed. There are shown:

[0057] FIG. 1 an intraoral scanning of a dentition of a patient;

[0058] FIG. 2 a preparation of a virtual model of a dental component adapted to the dentition of the patient with the aid of a computer-based program;

[0059] FIG. 3 a positioning of virtual base bodies with the aid of the program;

[0060] FIG. 4 a positioning of the virtual models on the virtual base bodies with the aid of the program;

[0061] FIG. 5 a production of a virtual structure on the basis of the virtual models with the aid of the program;

[0062] FIG. 6 a physical structure that was produced on the basis of the virtual structure;

[0063] FIG. 7 an embedding of the physical structure in an investment material to produce an embedded body;

[0064] FIG. 8 a burning out of the physical structure from the embedded body to produce a negative mold;

[0065] FIG. 9 an insertion of a raw material required for the production of the dental components and of pressing punches into the negative mold;

[0066] FIG. 10 a deflasking of the dental component with the aid of a deflasking device; and

[0067] FIG. 11 an embodiment of the system in accordance with the invention.

[0068] FIGS. 1 to 10 show the individual steps of an embodiment of the method in accordance with the invention.

[0069] A first step of the method in accordance with the invention is shown schematically in FIG. 1. A part of a dentition 42 of a patient is scanned intraorally (indicated by the reference numeral 26) with the aid of a scanning apparatus 40. The part of the dentition 42 has the gums 56 of the dentition, two defect-free teeth 68, and a defective tooth 70 requiring a partial dental prosthesis. It is generally also conceivable that a (negative) impression of the dentition 42 is produced. This impression can then be scanned. However, it is also possible by means of the impression to produce a (positive) physical model of the dentition 42 that is then scanned.

[0070] The scan data form the basis for a virtual model 42.V of the scanned part of the dentition 42 (see FIG. 2).

[0071] FIGS. 2 to 5 show a graphical user interface 58 of a computer-based program for virtually processing the virtual model 42.V, wherein the graphical user interface 58 has a toolbar 60 by means of which different tools can be selected for preparing and processing a virtual model 14 of a dental component provided for the reconstruction of the defective tooth 70.

[0072] In FIG. 2, the virtual model 14 of this partial dental prosthesis is shown that is adapted to the previously prepared virtual dentition 42.V. The virtual dentition 42.V comprises virtual gums 56.V and a virtual, defective tooth 70.V. For example, the virtual dentition 42.V is based on the previously performed intraoral scan 26. With the aid of the computer-based program, the virtual model 14 can be adapted for the defective tooth 70 such that the dentition 42 of the patient can be repaired using a dental component 10 based on the virtual model 14. For example, the virtual model 14 can be automatically or manually taken from a database comprising a plurality of standard models. If necessary, the selected standard model can be adapted to the respective present situation to create a virtual model 14 that is optimized from the point of view of dental technology. In other words: The adaptation can take place automatically, semi-automatically (e.g. a manual adaptation of a basic model or of a standard model), or manually.

[0073] In principle, the preparation of a physical model of the virtual model 14 can now be started. However, a plurality of physical models are frequently produced at the same time for the simultaneous manufacture of a plurality of dental components for different patients in order to save costs.

[0074] For the embedding of the physical model still described in the following, it is advantageous if it is arranged on a kind of base or on a base body. This can also be planned with the aid of the program. The program can e.g. automatically determine how a plurality of physical models are spatially arranged as advantageously as possible to be able to simultaneously manufacture as many dental components as possible with one process run (this planning can also take place manually or with manual support). For this purpose, a plurality of base bodies are necessary under certain circumstances. In the present example, the program suggests an arrangement of three base bodies (virtual base bodies 30.V) (see FIG. 3). The arrangement of the base bodies 30.V can also be predefined by apparatus framework conditions, e.g. by a configuration of the furnace and/or by a design of a pressing apparatus of the furnace. The virtual base bodies 30.V can be connected to one another by virtual webs (not shown).

[0075] In the next step shown in FIG. 4, three virtual models 14 are arranged above the three virtual base bodies 30.V such that the virtual models are indeed disposed close to the virtual base bodies 30.V, but there are still no points of contact.

[0076] FIG. 5 represents a planning step in which virtual connection webs 34.V are inserted (automatically, manually, or partly manually) between the virtual base bodies 30.V and the virtual models 14. The connection webs 34.V connect the virtual base bodies 30.V to the virtual models 14. Thus, a virtual structure 72 was created by means of which a physical structure can be produced that forms the basis for preparing a suitable negative mold.

[0077] It is understood that the virtual production and processing of the structure 72 can generally take place automatically. However, there is preferably the possibility that an operator can make adjustments as required in all the planning steps.

[0078] FIG. 6 shows a physical structure 74 that was produced on the basis of the structure 72 virtually designed in FIGS. 2 to 5. The structure 74 has three physical models 16 that are each a physical copy of the corresponding virtual model 14 and that are each connected to a respective at least one base body 30 via at least one connection web 34. Connection webs can generally also be provided between the models 16 and the base bodies 30. They can subsequently be manually inserted or can already be taken into account in the virtual planning.

[0079] The structure 74 can be manufactured on the basis of the previously prepared virtual structure 72 by means of an additive manufacturing process, in particular by means of 3D printing. However, it is also possible to manufacture the structure 74 or individual parts thereof in a different manner—in particular by a stripping process, for example by means of milling—and/or to rework the structure 74, in particular manually.

[0080] On a production of the structure 74 by means of 3D printing, it is advantageous if all three basic components—models 16, base body 30, and connection webs 34—are produced from the same model material (e.g. a wax-like material and/or plastic). If the three components were only partly produced together or were even produced in individual steps using different methods, the three components thus preferably likewise have the same or at least a similar material. The materials used preferably have a similar melting behavior. The model material is in particular combustible without residue. The material preferably has a melting point, a boiling point, or a sublimation point in a range from above room temperature to 900° C.

[0081] A particularly suitable 3D printing process is, for example, stereolithography, in which a light-curing plastic is used.

[0082] The structure 74 produced is positioned in a well-defined position and alignment on a base plate 62 and is preferably fixed there. It can also be manufactured (e.g. printed) directly on the base plate 62.

[0083] As is shown in FIG. 7, a sleeve 64 is placed onto the base plate 62 so that it surrounds the structure 74 and is, for example, fastened to the plate 62 by means of a plug-in connection. The sleeve 64 forms a cup-like cylinder 78, which is open at one side, with the base plate 62. A suitable investment material 18 is now inserted into the inner space of the cylinder 78. The investment material 18 can be a gypsum-like material and/or phosphate-bonded and/or ethyl silicate-bonded.

[0084] After the curing of the investment material 18, the sleeve 64 and the base plate 62 are removed. This can in particular be promoted in that the inner sides of the sleeve 64 and of the base plate 62 are wetted with a separation means prior to the assembly and/or have a corresponding surface coating.

[0085] FIG. 8 shows a further step in the production of a dental component. The cured investment material 18 forms an embedded body 18A that is now inserted into a programmable burnout furnace 12A. The embedded body 18A is positioned such that the end face 84 of the cylindrical, cured investment material 18 formed by the base plate 62 faces downwardly.

[0086] The process parameters for operating the burnout furnace 12A can be selected automatically, manually, or partly manually on the basis of the virtual model 14, the virtual components 30.V, 34.V (see FIGS. 2 to 5), and/or the total virtual structure 72. The goal is to ensure that the models 16, the connection webs 34, and the base bodies 30 are removed as efficiently and completely as possible by a burning out of the cured investment material 18. For this purpose, suitable process parameters, such as a maximum temperature, a temperature development, and/or a firing duration, are selected to melt the material of the aforementioned components and/or to burn it off without residue without damaging the embedded body. The melted material or the combustion products of the material can flow out or escape from the body 18A.

[0087] The process parameters mentioned can naturally also be taken from a database or can be based on empirical values.

[0088] A negative mold 20 of the models 16, of the connection webs 34, and of the base bodies 30 results from the process of burning out the models 16, the connection webs 34, and the base bodies 30 from the embedded body 18A. The negative mold 20 thus has channels 32 that are negative impressions of the base bodies 30.

[0089] In FIG. 9, it is schematically shown how pellets 22 of a raw material are inserted into the channels 32 of the negative mold 20. Said raw material is preferably divided into portions such that it corresponds to the amount required for the respective dental component 10. The required amount can, for example, be determined from the virtual model 14. The raw material can also be introduced as powder, pellets, or in another form. It is melted in a dental furnace 12 and is pressed into the negative impressions of the models 16 via the negative impressions of the connection webs 34 (=connection passages) on the application of a pressing force to ensure a complete and pore-free filling of the impressions of the models 16. Connection passages between the models 16 and/or the channels 32 facilitate the exchange of melted raw material within different regions of the negative mold 20.

[0090] The pressing force is generated by a pressing device 48 associated with the furnace 12 and is transmitted to the raw material by means of pressing punches 80. The pressing force can be generated by an active movement of the punches 80 and/or by a movement of the negative mold 20 relative to the punches 80. The pressing force can be maintained constant or variable in time until the complete curing of the dental component produced. However, it is likewise possible that the pressing force is, for example, only applied until the raw material 22 has fully penetrated into the negative mold of the models 16.

[0091] A control device is associated with the dental furnace 12 by which said dental furnace 12 can be controlled. The dental furnace 12 is preferably freely programmable. The process parameters of a firing program—e.g. pressing force and temperature—are determined on the basis of the properties of the virtual model 16 and/or of the virtual structure 72. The type and/or the properties of the raw material used can in this respect be taken into account. It is e.g. possible for the operator to input this information manually and/or to obtain it from a database and to integrate it into the virtual model when planning the latter. The virtual model then therefore not only includes geometric information, but also information that characterizes the material. Based on, for example, the design of the dental components to be produced, the required amount of raw material 22 and the spatial position, the volume and/or the geometry of the negative impressions of the models 16 in the negative mold 20 (the number and position of the base bodies 30 can also be taken into account), a firing program can be automatically suggested by the control device, said firing program being defined by suitable process parameters that can also be a function of time if required. For example, the firing program is calculated or produced (in part) from suitable parameters of the present virtual models 16 or of the virtual structure 72. It is also possible that the firing program is (partly) taken from a program library, wherein parameters of the present virtual models 16 or of the virtual structure 72 are taken into account when selecting the suitable firing program. The suggested and/or produced firing program can be modified by an operator as required. A purely manual definition of the firing program is also conceivable in principle.

[0092] After the curing and cooling of the raw material in the negative mold 20, the investment material 18 is removed. This can take place manually. However, it is more efficient to at least partly automate the deflasking.

[0093] For this purpose, a deflasking device 50 is provided (see FIG. 10a) that removes the material 18 by means of compressed air blasting using a solid blasting means (see nozzles 50.1, 50.2) or by means of water blasting. Other stripping processes such as milling and/or combinations of different processes can also be used.

[0094] The position of the produced dental components in the mold 20 is known based on the data of the virtual structure 72 and due to the well-defined fixing of the physical structure 74 on the base plate 62. If the mold 20 is now positioned in a known alignment and position in the deflasking device 50, said data can serve as a basis for a control of the deflasking device 50. Said deflasking device 50 is controlled such that the material 18 is efficiently removed without damaging the components. An intervention by an operator nevertheless remains possible, should it be necessary. Provision can also be made that only a rough removal of the material 18 is performed in an automated matter and the final deflasking takes place manually. Larger regions of the body 18A in which no components are included can also be detached, in particular cut off, as whole pieces in a manual, semi-automated, or automated manner.

[0095] The type and/or the properties of the investment material 18 can be taken into account in the automated or semi-automated deflasking. For example, corresponding information is input manually or is taken from a database.

[0096] Markings and/or mechanical codings can be provided to facilitate the positionally accurate and reproducible positioning of the structure 74 on the base plate 62 (or on a comparable base unit) and/or of the mold 20 in the device 50.

[0097] FIG. 10b shows the result of the deflasking. The dental components 10 produced by means of the mold 20 are also connected to the raw material (webs 34.R) that is cured in the passages produced by the webs 34 and that is in turn connected to raw material cured in the channels 32 (see reference letter 32.R). The components 10, 34.R, and 32.R are an at least partial copy of the physical structure 74 (the base bodies 30 are generally not completely reproduced) that is anchored in a base 82 (remainder of the negative mold 20). The dental components 10 can now be detached and reworked as required.

[0098] FIG. 11 schematically shows a system in accordance with the invention. The raw data 112 acquired by a raw data acquisition device 110 (e.g. a scanner 40, see FIG. 1) are fed to a control 100 that can be a control and regulation device. It forwards the raw data 112 to a model planning module 120 that is, for example, a program module that is integrated into the control 100 or that runs on a separate processing unit.

[0099] A virtual model of the required dental component and/or of a structure including the component is—automatically, semi-automatically, or manually—generated on the basis of the raw data 112 with the aid of the model creation module 120 (see e.g. FIGS. 2 to 5). Corresponding model data 122 are transmitted via the control 100 or directly (see dashed arrow) to a model manufacturing device 130 (e.g. a 3D printer), where a physical model or a physical structure of the virtual model or of the virtual structure is produced (see e.g. FIG. 6). It is also possible that the model data 122 are first converted into operating parameters 132 and/or into a corresponding operating program for the device 130. The parameters or the program 132 can be input by an operator at the device 130 or at the control 100. However, the corresponding parameters or the corresponding program 132 are preferably automatically produced or selected on the basis of the model data 122 and—if necessary—modified by the operator as required.

[0100] After the embedding of the physical model or of the physical structure, the embedded body obtained is burned out in a programmable furnace 140 (e.g. a burnout furnace 12A, FIG. 8). The operating parameters 142 required for this purpose and/or a corresponding operating program can be input by an operator at the furnace 140 or at the control 100. However, the corresponding parameters or the corresponding program 142 are preferably automatically produced or selected on the basis of the model data 122 (wherein the type and/or the properties of the model material is/are preferably also taken into account) and—if necessary—modified by the operator as required.

[0101] The burnout process provides a negative mold of the physical model or physical structure. The mold is filled with the material of the dental component (see e.g. FIG. 9) and is fired in a programmable dental furnace (e.g. furnace 12)—optionally with a pressing device. The operating parameters 152 required for this purpose and/or a corresponding operating program can be input by an operator at the furnace 150 or at the control 100. However, the corresponding parameters or the corresponding program 162 are preferably automatically produced or selected on the basis of the model data 122 (wherein the type and/or the properties of the raw material is/are preferably also taken into account) and—if necessary—modified by the operator as required.

[0102] The component produced in the negative mold now has to be removed from the investment material. For this purpose, a deflasking apparatus 160 is provided (see e.g. the deflasking device 50, FIG. 10). The deflasking can generally take place manually. However, this step is preferably also performed in a completely automated manner or in an at least partly automated manner (e.g. “rough” deflasking in an automated manner, concluding “final deflasking” in a manual manner). The operating parameters 162 required for this purpose and/or a corresponding operating program can be input by an operator at the apparatus 160 or at the control 100. However, the corresponding parameters or the corresponding program 162 are preferably automatically produced or selected on the basis of the model data 122 (wherein the type and/or the properties of the raw material is/are preferably also taken into account) and—if necessary—modified by the operator as required.

[0103] A single control 100 was shown by way of example. However, it is also conceivable to provide two or more control units that each control and/or regulate parts of the process or one or more of the functional units 110, 120, 130, 140, 150, 160 described above. The control units can also be connected between a higher-ranking control and the functional units. The data exchange between the control or the control unit(s) and the functional units and/or among the control units themselves and/or among the functional units themselves (shown by way of example at the units 120, 130; if required, the other or some of the other units can also be connected to one another) preferably takes place via a network, e.g. via the Internet and/or via a local network (in a wireless and/or wired manner). Parts of the system can thus be arranged spatially separated from one another to make ideal use of resources.

[0104] Any necessary data format conversions or modifications of the data, e.g. a conversion of visualization data records into CAD data records or similar, can be performed at any desired point in the system. The same applies to the automatic or semi-automatic production and/or selection of the model parameters or model data or operating parameters or operating data 122, 132, 142, 152, 162.

[0105] The system in accordance with the invention or the corresponding method is based on a use of virtual data that is as efficient as possible to control different apparatus that are required to produce a dental component. Interventions by an operator are minimized, which is accompanied by cost advantages. The linking of the components of the system allows the spatial separation of individual process steps to be able to exploit specific location advantages in each case. For example, the planning of the dental component, that is the virtual preparation of the actual manufacturing steps, can take place at a different location than the actual manufacturing steps.

REFERENCE NUMERAL LIST

[0106] 10 dental component [0107] 12 dental furnace [0108] 12A burnout furnace [0109] 14 virtual model [0110] 16 physical model [0111] 18 investment material [0112] 18A embedded body [0113] 20 negative mold [0114] 22 raw material pellet [0115] 26 intraoral scanning [0116] 30 physical base body [0117] 30.V virtual base body [0118] 32 channel [0119] 32.R cured raw material in the channel 32 [0120] 34 physical connection web [0121] 34.R web composed of cured raw material [0122] 34.V virtual connection web [0123] 40 scanning apparatus [0124] 42 physical dentition [0125] 42.V virtual dentition [0126] 48 pressing device [0127] 50 deflasking device [0128] 50.1, 50.2 nozzle [0129] 56 physical gums [0130] 56.V virtual gums [0131] 58 graphical user interface [0132] 60 toolbar [0133] 62 base plate [0134] 64 sleeve [0135] 68 healthy tooth [0136] 70 damaged tooth [0137] 70.V virtual damaged tooth [0138] 72 virtual structure [0139] 74 physical structure [0140] 78 cylinder [0141] 80 pressing punch [0142] 82 base [0143] 110 raw data acquisition device [0144] 112 raw data [0145] 120 model planning module [0146] 122 model data [0147] 130 model manufacturing device [0148] 140, 150 programmable furnace [0149] 132, 142, 152, 162 operating parameters, operating program [0150] 160 deflasking apparatus