DE102023106493A1 - CAD-CAM process for designing and manufacturing dental prostheses as well as transfer table and articulator for carrying out such a process - Google Patents

Abstract

The present invention relates to a CAD-CAM method for designing and producing dental prostheses (19) in the form of a crown, bridge, dental prosthesis or the like. The invention further relates to an articulator (9) and a transfer table (8) geometrically matched to it for carrying out such a method.

Description

The present invention relates to a CAD-CAM method for designing and producing dental prostheses in the form of crowns, bridges, dental prostheses or the like. Furthermore, the present invention relates to a transfer table and an articulator for carrying out such a method.

CAD-CAM processes for designing and manufacturing dental prostheses are already known in the state of the art. They can be used to produce crowns, bridges, fixed, implant-supported and removable prostheses, abutments, inlays, onlays, long-term provisionals or the like, but also aligners and other aids used in orthodontics, which are also included under the generic term "dentures" in the context of this application. CAD is the abbreviation for "Computer Aided Design" and CAM is the abbreviation for "Computer Aided Manufacturing". The basis for CAD-CAM processes is a CAD-CAM program provided on a computer system that is designed for the design and manufacture of dentures. A distinction is currently made between direct, semi-direct or indirect CAD-CAM processes. In the direct CAD-CAM process, all steps are carried out on site in the dentist's office, usually in a single session. For this purpose, a digital lower jaw model, a digital upper jaw model and optionally at least one digital vestibular model are first created by scanning the oral cavity of a patient. For this purpose, a so-called oral scanner is used, which is also often referred to as an oral camera. The digital lower and upper jaw models contain the positional relationships of the adjacent teeth, and the verstibular model contains the positional relationship to the teeth of the opposing jaw. In a further step, the digital models created are transferred to a computer system on which the CAD-CAM program is stored. Based on the digital models, the dentures can then be digitally designed using the CAD-CAM program, whereby a digital denture model is created. Based on this digital denture model, control commands are generated in the CAD-CAM program for a processing machine that is used to produce the designed dentures. The processing machine can be designed to carry out an additive manufacturing process by adding material and/or a subtractive manufacturing process by removing material. The additive manufacturing processes, which are often summarized under the term 3D printing, primarily include fused deposition modeling, stereolithography, selective laser melting and laser sintering, with which a wide variety of materials can be processed, in dentistry currently primarily resins, plastics, ceramics and hybrid materials. Milling and grinding are mainly used as subtractive manufacturing processes. The control commands generated by the CAD-CAM program are transmitted to the processing machine set up in the dentist's office, which produces the dentures based on the control commands. This means that dentures can be made available in the dentist's office within a short period of time without having to consult a dental technician. The semi-direct CAD-CAM process differs from the direct CAD-CAM process in that the digital lower jaw, upper jaw and optionally vestibular models created by the dentist are transmitted to a dental laboratory, which then takes over the design and manufacture of the dentures. In the indirect CAD-CAM process, the dentist makes conventional impressions of the upper and lower jaw, after which the impressions are sent to a dental laboratory or a milling center. There, the impressions are digitized, after which the dentures are designed and manufactured in the manner described above. The semi-direct and indirect CAD-CAM processes are used in particular when the design of the dentures is too complex and therefore too time-consuming to be carried out on site in the dentist's office. The material desired by the patient from which the dentures are to be made can also be a reason for outsourcing to a dental technician.

For some dental prostheses, particularly those which have areas in the occlusal plane, it is desirable for the dental technician to check the accuracy of the fit of the manufactured dental prosthesis using an articulator and, if necessary, to optimize it before the dentist fits the patient. An articulator is a device for simulating the movement of the jaw joint into which models of the upper and lower jaws are mounted in occlusion. These models are normally made of plaster of Paris or a similar material. In the indirect CAD-CAM process, the dentist uses a facebow to make plaster casts of the upper and lower jaws and a bite impression. A facebow is a device that enables parameters recorded individually on the patient to be transferred to the articulator, namely the relative position of the upper jaw, represented by a bite fork coated with an impression material, to the jaw joint, which is simulated by both the facebow and the articulator. A holding device, by means of which the bite fork is detachably held on the face bow, is detached from the face bow together with the bite fork held on it after the bite impression has been made and can then be removed from the Dental technicians can place the model in a suitable holder on the articulator. The upper jaw model can then be aligned with the bite impression and fixed to the articulator in this aligned state, normally using a plaster-like mass. In a further step, the lower jaw model is placed against the upper jaw model, aligned in this way and also fixed to the articulator in this aligned state. The dental technician can now check the accuracy of fit of the manufactured dentures on the model and optimize it if necessary. A disadvantage of this procedure is that at least the patient-specifically fixed joint piece with the bite fork held to it and containing the bite impression must be sent from the dentist to the dental technician, which is time-consuming and costly. In addition, when using facebows whose holders have a large number of fixable joints that are fixed to the patient by the dentist, there is a risk that the fixations will come loose during transport to the dental technician, meaning that the patient-specific settings are lost. In order to prevent the latter, it is known to position the holding device with the bite fork held on it in a holder of a so-called transfer table at the dentist's. After appropriate positioning, the bite fork is fixed to an adapter plate of the transfer table using a plaster-like mass, which is detachably held on a base plate of the transfer table. After the plaster-like mass has hardened, the holding device is removed, whereupon the adapter plate with the bite fork held on it can be detached from the transfer table and taken to the dental technician. There, the dental technician attaches the adapter plate to a corresponding base plate of the articulator so that the bite fork with the bite impression is correctly positioned in relation to the hinge axis of the articulator, which simulates the human jaw joint, while maintaining the patient-specific parameters recorded with the facebow.

Based on this prior art, it is an object of the present invention to provide an improved method of the type mentioned at the outset.

1. a) Bereitstellen eines Computersystems, von dem aus mit einem zahntechnischen CAD-CAM-Programm gearbeitet werden kann, das für das Gestalten und Herstellen von Zahnersatz (19) ausgelegt ist und einen virtuellen Artikulator beinhaltet;
2. b) Erstellen eines digitalen Unterkiefermodells (17'), eines digitalen Oberkiefermodells (16') und optional zumindest eines digitalen Vestibulärmodells durch Scannen des Mundraums eines Patienten, wobei die digitalen Modelle von dem CAD-CAM-Programm verarbeitet werden können;
3. c) Erfassen der Lagebeziehung des Oberkiefers zu den Kiefergelenken und zur Schädelbasis des Patienten unter Verwendung eines Gesichtsbogens (3), an dem eine mit einem Abdruckmaterial bestrichene Bissgabel (4) über eine lösbar an dem Gesichtsbogen (3) befestigte Halteeinrichtung (5) gehalten ist;
4. d) Positionieren der von dem Gesichtsbogen (3) gelösten Halteeinrichtung (5) und daran gehaltener, nunmehr einen Bissabdruck (6) aufweisender Bissgabel (4) an einer Halterung (7) eines Übertragungstisches (8), an dem zumindest ein dreidimensionaler Scanmarker (10) angeordnet ist;
5. e) optional Formen eines Übergangs (14) von dem zumindest einen Scanmarker (10) zur Bissgabel (4) unter Verwendung eines weichen, elastischen Materials;
6. f) Erstellen eines digitalen Übertragungstischmodells (15'), das die Lagebeziehung zwischen dem Bissabdruck (6) und dem zumindest einen Scanmarker (10) beinhaltet, durch Scannen der Anordnung;
7. g) Übermitteln der in Schritt b) erstellten digitalen Modelle und des in Schritt f) erfassten digitalen Übertragungstischmodells (15') an das Computersystem;
8. h) Matchen des im digitalen Übertragungstischmodell (15') enthaltenen zumindest einen Scanmarkers (10') mit zumindest einem im CAD-CAM-Programm hinterlegten digitalen Scanmarker des virtuellen Artikulators, dessen Position, Form und Ausrichtung der Position, Form und Ausrichtung des am Übertragungstisch (8) positionierten zumindest einen Scanmarkers (10) entspricht, derart, dass das CAD-Programm die relative Lage zwischen dem digitalen Bissabdruck (6') des digitalen Übertragungstischmodells (15') und dem zumindest einen digitalen Scanmarker (10') des CAD-CAM-Programms erfasst;
9. i) Matchen des digitalen Bissabdrucks (6') des digitalen Übertragungstischmodells (15') mit dem digitalen Oberkiefermodell (16') derart, dass das CAD-CAM-Programm die relative Lage zwischen dem digitalen Oberkiefermodell (16') und dem digitalen Bissabdruck (6') erfasst;
10. j) Matchen des digitalen Oberkiefermodells (16') und des digitalen Unterkiefermodells (17'), optional unter Berücksichtigung des zumindest einen digitalen Vestibulärmodells derart, dass das CAD-CAM-Programm die relative Lage zwischen dem digitalen Oberkiefermodell (16') und dem digitalen Unterkiefermodell (17') erfasst;
11. k) digitales Gestalten des Zahnersatzes (19) unter Verwendung des CAD-CAM-Programms unter Erstellung eines digitalen Zahnersatzmodells (19') und
12. l) Herstellen des gestalteten Zahnersatzes (19) unter Verwendung des digitalen Zahnersatzmodells (19'), insbesondere mittels Druckens und/oder Fräsens und/oder Schleifens.

To achieve this object, the present invention provides a CAD-CAM method for designing and producing dental prostheses (19) in the form of a crown, bridge, dental prosthesis or the like, which comprises the following steps:

1. a) providing a computer system from which it is possible to work with a dental CAD-CAM program which is designed for the design and manufacture of dental prostheses (19) and includes a virtual articulator;
2. b) creating a digital lower jaw model (17'), a digital upper jaw model (16') and optionally at least one digital vestibular model by scanning the oral cavity of a patient, wherein the digital models can be processed by the CAD-CAM program;
3. c) detecting the positional relationship of the upper jaw to the jaw joints and to the skull base of the patient using a facebow (3) to which a bite fork (4) coated with an impression material is held via a holding device (5) detachably attached to the facebow (3);
4. d) positioning the holding device (5) detached from the facebow (3) and the bite fork (4) held thereon, now having a bite impression (6), on a holder (7) of a transfer table (8) on which at least one three-dimensional scan marker (10) is arranged;
5. e) optionally forming a transition (14) from the at least one scan marker (10) to the bite fork (4) using a soft, elastic material;
6. f) creating a digital transfer table model (15') which includes the positional relationship between the bite impression (6) and the at least one scan marker (10) by scanning the arrangement;
7. g) transmitting the digital models created in step b) and the digital transfer table model (15') captured in step f) to the computer system;
8. h) matching the at least one scan marker (10') contained in the digital transfer table model (15') with at least one digital scan marker of the virtual articulator stored in the CAD-CAM program, the position, shape and orientation of which corresponds to the position, shape and orientation of the at least one scan marker (10) positioned on the transfer table (8), such that the CAD program detects the relative position between the digital bite impression (6') of the digital transfer table model (15') and the at least one digital scan marker (10') of the CAD-CAM program;
9. i) matching the digital bite impression (6') of the digital transfer table model (15') with the digital upper jaw model (16') such that the CAD-CAM program records the relative position between the digital upper jaw model (16') and the digital bite impression (6');
10. j) matching the digital upper jaw model (16') and the digital lower jaw model (17'), optionally taking into account the at least one digital vestibular model, such that the CAD-CAM program detects the relative position between the digital upper jaw model (16') and the digital lower jaw model (17');
11. k) digital design of the dental prosthesis (19) using the CAD-CAM program to create a digital dental prosthesis model (19') and
12. l) producing the designed dental prosthesis (19) using the digital dental prosthesis model (19'), in particular by means of printing and/or milling and/or grinding.

For the design and manufacture of dental prostheses, for example in the form of crowns, bridges, fixed, implant-supported and removable prostheses, abutments, inlays, onlays, long-term provisionals or the like, but also aligners and other aids used in orthodontics, which are also included under the generic term "dental prostheses" in the context of the present application, a CAD-CAM program is used according to the present invention, analogous to the prior art, which is designed for these purposes. First, the dentist creates a digital lower jaw model, a digital upper jaw model and optionally at least one digital vestibular model by scanning the oral cavity of a patient with an oral scanner in the manner already described above, the digital models being provided in a form that can be processed by the CAD-CAM program. The respective digital models can be generated as separate data sets, or alternatively as a single data set. In a further step, the positional relationship of the upper jaw to the jaw joints and the base of the patient's skull is then recorded using a facebow, to which a bite fork coated with an impression material is held via a holding device that is detachably attached to the facebow and preferably has several adjustable and fixable joints, which has also already been explained above. According to the invention, the holding device detached from the facebow and adjusted to the patient's specific needs, with the bite fork held thereon and now having a bite impression, is then positioned on a holder of a transfer table on which at least one three-dimensional scan marker is arranged. A suitable geometry of the transfer table can be used as a scan marker. Alternatively, a separate scan marker can also be arranged on the transfer table, which then only fulfills the marker function. The structure of the transfer table is known for fixing the skull axis-related position of the upper jaw obtained using the facebow and for transferring it to the articulator. A transition from the at least one scan marker to the bite fork is now formed using a soft, plastic material, since intraoral scanners currently available on the market can almost only scan connected objects. Otherwise, forming a transition can be omitted. In a further step, a digital transfer table model is created that contains the positional relationship between the bite impression and the at least one scan marker by scanning the arrangement, for example also using an oral scanner. The digital models of the lower jaw and the upper jaw, if applicable the digital vestibular model and the digital transfer table model recorded in the last step are now transmitted to the computer system. Here, the at least one scan marker contained in the digital transfer table model is matched with a digital scan marker of a virtual articulator stored in the CAD-CAM program, whereby the position, shape and orientation of the digital scan marker correspond to the position, shape and orientation of the scan marker positioned on the transfer table. The matching is carried out in such a way that the CAD program records the relative position between the digital bite impression of the digital transfer table model and the digital scan marker of the CAD-CAM program. Furthermore, the digital bite impression of the digital transfer table model is matched with the digital upper jaw model in such a way that the CAD-CAM program records the relative position between the digital upper jaw model and the digital bite impression. In addition, the digital upper jaw model and the digital lower jaw model are matched, optionally taking into account at least one digital vestibular model, in such a way that the CAD-CAM program records the relative position between the digital upper jaw model and the digital lower jaw model. Through the matching, the patient-specific positional relationships of the upper and lower jaw to the jaw joint for the digital upper and lower jaw model are transferred to the CAD-CAM program, with the digital scan marker serving as a reference point. In this way, the digital upper and lower jaw models are fitted into the digital articulator in a patient-specific manner while retaining the parameters recorded via the facebow at the dentist. The denture is now digitally designed using the CAD-CAM program to create a digital denture model. In a further step, the designed denture is manufactured using the digital denture model, in particular by means of printing and/or milling and/or grinding. For this purpose, based on the digital denture model, the CAD-CAM program, as described at the beginning, As already described, control commands are generated for a processing machine that is used to manufacture the designed dental prosthesis.

According to one embodiment of the method according to the invention, an upper jaw model and a lower jaw model are produced in a step m) based on the digital upper jaw model and the digital lower jaw model, in particular by means of printing and/or milling and/or grinding. For this purpose, control commands are generated in the CAD-CAM program based on the digital upper and lower jaw models, which are then forwarded to a suitable processing machine in which the models are then manufactured.

Preferably, the upper jaw model and the lower jaw model are then fixed in an articulator in a further step n), taking into account the relative positions recorded in steps h) to j).

According to a variant of the method according to the invention, several scan markers are provided distributed on the transfer table and on the virtual articulator, the positions, shapes and orientations of which correspond to one another. After matching, the digital upper jaw model is provided with digital support pins in the CAD program, which connect the digital upper jaw model to the digital scan markers, after which the upper jaw model is produced including the support pins. The support pins are then placed on bases of the articulator, the respective positions, shapes and orientations of which correspond to the scan markers positioned on the transfer table, after which the upper jaw model is fixed in this position on the articulator, for example using a plaster-like mass.

The lower jaw model is preferably placed against the upper jaw model fixed to the articulator and fixed in this position to the articulator. This requires that the upper and lower jaw models have a sufficient number of teeth in the occlusal plane, which can be used to determine the correct relative position between the upper and lower jaw models when manually placing the lower jaw model on the upper jaw model already fixed to the articulator.

Alternatively, the digital lower jaw model is provided with digital support pins in the CAD program, which connect the digital lower jaw model to the digital support pins of the upper jaw model, after which the lower jaw model is produced including the support pins. The support pins are placed on the digital support pins of the upper jaw model when the lower jaw model is inserted into the articulator, after which the lower jaw model is fixed in this position on the articulator.

According to one embodiment of the present invention, the at least one scan marker (10) provided on the transfer table (8) is height-adjustable via a height adjustment device (12), wherein the height adjustment device (12) has a display device on which the set height can be read and/or a height marking (13) representing the set height, which is also scanned in step f) when creating the digital transfer table model (15'), and the articulator (9) has a height adjustment device (12) which preferably corresponds to the height adjustment device (12) of the transfer table (8).

In particular, the height of the at least one scan marker provided on the transfer table is adjusted in step d) via the height adjustment device such that it is positioned near the underside of the bite fork. Accordingly, the scan marker is positioned near the occlusal plane.

According to one embodiment of the method according to the invention, in order to bridge a gap between the upper and lower jaw models positioned on the articulator with due consideration of the occlusal plane and fastening devices designed on the articulator for holding the upper jaw model and the lower jaw model, adapter plates are calculated in the CAD program, which are added to the digital upper and lower jaw model and with which the upper jaw model and the lower jaw model are produced in step m). The upper and/or lower jaw model can then be fixed to the articulator using these adapter plates.

Preferably, the adapter plates and the fastening devices have interlocking sections which align the adapter plates when arranged on the fastening devices.

Furthermore, the adapter plates and the fastening devices can have means for releasably fixing them to one another, for example by creating a snap-in connection, magnetic connection or the like.

Furthermore, the present invention provides an articulator and a transfer table geometrically matched to the articulator for carrying out a method according to the invention, characterized in that the transfer table has a holder for receiving a removable joint piece of a face bow and at least three scan markers are positioned on the transfer table, and that at least three bases are positioned on the articulator, the respective positions, shapes and orientations of which correspond to the scan markers positioned on the transfer table.

The scan markers provided on the transfer table are preferably jointly height-adjustable via a height adjustment device, wherein the height adjustment device has a display device on which the set height can be read and/or a height marking representing the set height, and the bases provided on the articulator are preferably jointly height-adjustable via a height adjustment device analogous to the scan markers provided on the transfer table, wherein the height adjustment device has a display device on which the set height can be read and/or a height marking representing the set height.

Furthermore, the present invention provides a computer program comprising instructions which, when executed on at least one computer, cause the at least one computer to carry out the steps of the method according to the invention.

In addition, the present invention provides a computer-readable medium comprising instructions which, when executed on at least one computer, cause the at least one computer to perform the steps of the method according to the invention.

Finally, the present invention provides a device for data processing comprising a processor, a data storage device on which computer-executable program code is stored which, when executed by the processor, causes it to carry out the steps of the method according to the invention.

• 1a bis 11f schematische Ansichten aus verschiedenen Perspektiven eines Patienten während der Durchführung eines Oralscans zur Erstellung eines digitalen Oberkiefermodells, eines digitalen Unterkiefermodells und optional eines digitalen Vestibulärmodells;
• 2a bis 2f schematische, teilweise durchsichtig dargestellte Ansichten aus verschiedenen Perspektiven eines Patienten während der Abnahme eines Bissabdrucks unter Verwendung eines Gesichtsbogens;
• 3a bis 3f schematische Ansichten aus verschiedenen Perspektiven eines Übertragungstisches, an dessen Halterung eine Halteeinrichtung des in den 2a bis 2f gezeigten Gesichtsbogens mit daran angeordneter, einen Bissabdruck des Patienten aufweisender Bissgabel befestigt ist;
• 4a bis 4f schematische Ansichten aus verschiedenen Perspektiven des in den 3a bis 3f gezeigten Übertragungstisches während der Durchführung eines Scans;
• 5a bis 5f schematische Ansichten aus verschiedenen Perspektiven eines digitalen Übertragungstischmodells, welches das Ergebnis des im Rahmen des am Übertragungstisch durchgeführten Scans repräsentiert;
• 6a bis 6f schematische Ansichten aus verschiedenen Perspektiven, welche die Positionierung des digitalen Oberliefermodells relativ zu digitalen Scanmarkern zeigt, welche unter Verwendung eines CAD-CAM-Programms durchgeführt wird;
• 7a bis 7f schematische Ansichten aus verschiedenen Perspektiven, die das in den 6a bis 6f dargestellte digitale Oberkiefermodell zeigen, nachdem im CAD-CAM-Programm digital Supportstifte hinzugefügt wurden;
• 8a bis 8d schematische Ansichten aus verschiedenen Perspektiven, die ein Oberkiefermodell mit Supportstiften zeigen, das basierend auf dem in den 7a bis 7f dargestellten digitalen Oberkiefermodell mit digitalen Supportstiften hergestellt wurde;
• 9a bis 9d schematische Ansichten aus verschiedenen Perspektiven, die ein digitales Unterkiefermodell zeigen, nachdem im CAD-CAM-Programm digital Supportstifte hinzugefügt wurden;
• 10a bis 10f schematische Ansichten aus verschiedenen Perspektiven, die ein digital unter Verwendung des CAD-CAM-Programms gestaltetes Zahnersatzmodell zeigen;
• 11a bis 11f schematische Ansichten aus verschiedenen Perspektiven, die ein basierend auf dem in den 9a bis 9d gezeigten digitalen Unterkiefermodell hergestelltes Unterkiefermodell und einen basierend auf dem in den 10a bis 10f gezeigten digitalen Zahnersatzmodell hergestelltes Zahnersatzmodell im montierten Zustand zeigen;
• 12a bis 12e schematische Ansichten aus verschiedenen Perspektiven, die einen Artikulator mit eingesetztem Oberkiefermodell zeigen, das basierend auf dem in den 7a bis 7f dargestellten digitalen Oberkiefermodell gefertigt wurde;
• 13a bis 13f schematische Ansichten aus verschiedenen Perspektiven, die eine alternativen, mit Distanzplatten versehenen Artikulator zeigen, in den ein Oberkiefermodell eingesetzt ist, das basierend auf dem in den 7a bis 7f dargestellten digitalen Oberkiefermodell gefertigt wurde, wobei das digitale Oberliefermodell vorab zusätzlich mit einer Anschlussplatte versehen wurde; und
• 14a bis 14f schematische Ansichten aus verschiedenen Perspektiven der in den 13a bis 13f gezeigten Anordnung, wobei in den Artikulator zusätzlich ein Unterkiefermodell mit daran gehaltenem Zahnersatzmodell eingesetzt ist, wobei das Unterkiefermodell basierend auf dem in den 8a bis 8d dargestellten digitalen Unterkiefermodell gefertigt wurde, das zusätzlich mit einer Anschlussplatte versehen wurde.

Further features and advantages of the present invention will become apparent from the following description with reference to the accompanying drawings.

• 1a to 11f schematic views from different perspectives of a patient during an oral scan to create a digital maxillary model, a digital mandibular model and optionally a digital vestibular model;
• 2a to 2f schematic, partially transparent views from different perspectives of a patient during the taking of a bite impression using a facebow;
• 3a to 3f schematic views from different perspectives of a transfer table, on whose support a holding device of the 2a to 2f shown facebow with a bite fork attached to it, containing a bite impression of the patient;
• 4a to 4f schematic views from different perspectives of the 3a to 3f shown transfer table while performing a scan;
• 5a to 5f schematic views from different perspectives of a digital transfer table model, which represents the result of the scan performed on the transfer table;
• 6a to 6f schematic views from different perspectives showing the positioning of the digital overhead model relative to digital scan markers, which is performed using a CAD-CAM program;
• 7a to 7f schematic views from different perspectives that show the 6a to 6f show the digital maxillary model shown after support pins were digitally added in the CAD-CAM program;
• 8a to 8d schematic views from different perspectives showing a maxillary model with support pins, based on the model shown in the 7a to 7f shown digital maxillary model was made with digital support pins;
• 9a to 9d schematic views from different perspectives showing a digital mandibular model after support pins have been digitally added in the CAD-CAM program;
• 10a to 10f schematic views from different perspectives showing a dental prosthesis model digitally designed using the CAD-CAM program;
• 11a to 11f schematic views from different perspectives, which are based on the 9a to 9d shown digital mandibular model and a mandibular model based on the digital mandibular model shown in the 10a to 10f show the digital denture model produced in the assembled state;
• 12a to 12e schematic views from different perspectives showing an articulator with an inserted upper jaw model, which is based on the 7a to 7f shown digital maxillary model;
• 13a to 13f schematic views from different perspectives showing an alternative articulator equipped with spacers, into which an upper jaw model is inserted, which is based on the one shown in the 7a to 7f shown digital upper jaw model was manufactured, whereby the digital upper delivery model was additionally provided with a connection plate in advance; and
• 14a to 14f schematic views from different perspectives of the 13a to 13f shown arrangement, wherein a lower jaw model with a dental prosthesis model held thereon is additionally inserted into the articulator, wherein the lower jaw model is based on the 8a to 8d shown digital lower jaw model, which was additionally provided with a connection plate.

Identical reference numbers below refer to identical or similar components; reference numbers marked with an apostrophe refer to the digital version of the corresponding component.

In one embodiment of a CAD-CAM method for designing and producing dental prostheses, in a first step a) a computer system is provided from which a dental CAD-CAM program can be used that is designed for designing and producing dental prostheses and includes a virtual articulator. Such CAD-CAM programs are generally known in the prior art, which is why they will not be discussed in more detail below. According to the present application, the term "dental prostheses" includes crowns, bridges, fixed, implant-supported and removable prostheses, abutments, inlays, onlays, long-term provisionals or the like, but also aligners and other aids used in orthodontics. Such CAD-CAM programs are generally known in the prior art and are already available on the market.

In a second step b), a digital lower jaw model, a digital upper jaw model and optionally at least one digital vestibular model are created by scanning the oral cavity of a patient, whereby the digital models can be processed by the CAD-CAM program. 1 shows various perspective views of the head 1 of a patient whose oral cavity is being scanned using an oral scanner 2. The digital models can be created individually. Alternatively, it is also possible to capture all of the digital models mentioned in a single scan and subsequently separate them in the CAD-CAM program if necessary.

In a subsequent step c), the positional relationship of the patient's upper jaw to his or her jaw joints and the base of the skull is recorded using a facebow 3. A bite fork 4 coated on the upper side with an impression material is held on the facebow 3 via a holding device 5 which is detachably attached to the facebow 3 and has several adjustable and fixable joints. The use of such a facebow 3 is state of the art, which is why it will not be discussed further here.

In a subsequent step d), as shown in the individual views a to f in 3 As shown, the holding device 5, which has been detached from the facebow 3 and whose joints were fixed in a patient-specific manner in the previous step c), with the bite fork 4 held thereon, which now has a bite impression 6, is positioned on a holder 7 of a transfer table 8. The holder 7 only allows a single orientation of the holding device 5. The transfer table 8 simulates an articulator 9, which is used by a dental technician at a later point in time, see also the 12 to 14 The transfer table 8 comprises at least one, in this case four scan markers 10, which in the embodiment shown protrude upwards from a common plane. The scan markers 10 serve to clearly identify the position and orientation of the bite fork 4 and the bite impression 6 arranged on it. In the case shown, they are designed like pins and have at least upwardly protruding, undercut-free projections 11 and/or undercut-free recesses on their upper side, the function of which is explained in more detail below. In principle, however, it should be clear that the scan markers 10 can also have a number and/or a different structure than the structure shown. The positioning of the scan markers 10 can also be changed. In principle, it is also possible to use suitable geometries of the transfer table 8 as scan markers and thus dispense with separate scan markers. In the embodiment shown, the scan markers 10 are positioned on a height adjustment device 12, via which they can be adjusted in height together. The height adjustment device 12 has a height marking 13 representing the set height, by means of which the set height can be clearly determined. Alternatively or additionally, the height adjustment device 12 can also be equipped with a display device made of be permitted, such as with a display, a scale or the like, even if this is not shown here.

In a next step e), transitions 14 from the respective scan markers 10 to the bite fork 4 are formed using a soft, elastic material, for example from a modeling clay or the like. These transitions are intended to support the subsequent scanning process. If the scanning process can be carried out without such transitions 14, step e) can also be omitted. Furthermore, in the embodiment shown, the scan markers 10 are moved by adjusting the height of the height adjustment device 12 into a plane that is located close to below the occlusal plane.

Now, in step f), a digital transfer table model 15' is created that contains the positional relationship between the bite impression 6 and the scan markers 10 by scanning the arrangement consisting of the bite fork 4, bite impression 6, scan markers 10 and transitions 14 as well as height marking 13. In this way, the patient-specific parameters that were previously determined using the facebow 3, in particular the relative position of the bite impression 6 to the skull base or the jaw joint, are digitized. The scanning process is also carried out here, as in the 4a to f, preferably using an oral scanner 2. The to f show the result of the scanning process in the form of the digital transfer table model 15'.

In a further step g), the digital models created in step b) and the digital transfer table model 15' recorded in step f) are transmitted to the computer system.

Now, in step h), the scan markers 10' contained in the digital transfer table model 15' are matched with digital scan markers of the virtual articulator stored in the CAD-CAM program, whose respective positions, shapes and orientations correspond to those of the scan markers 10 positioned on the transfer table 8, in such a way that the CAD program records the patient-specific relative position between the digital bite impression 6' of the digital transfer table model 15' and the digital scan markers 10' of the CAD-CAM program.

In a further step i), the digital bite impression 6' of the digital transfer table model 15' is matched with the digital upper jaw model 16' in such a way that the CAD-CAM program records the relative position between the digital upper jaw model 16' and the digital bite impression 6'. The result is shown in Figures a to f of the 6 The digital maxillary model 16' of the 6 digital transfer table model 15' shown as shown in the 7a to 7f shown, in the present case now provided with L-shaped digital support pins 18', which connect the digital upper jaw model 16' with the digital scan markers 10'. The free ends of the digital support pins 18' are designed in such a way that they can be placed in a form-fitting manner on the respective digital scan markers 10'. In the present case, they are thus provided with recesses/protrusions which accommodate the projections 11'/depressions of the scan markers 10'.

Likewise, in this variant of the method according to the invention, the digital lower jaw model 17', which is in the 9a to 9d shown, in the CAD-CAM program with digital support pins 18', which connect the digital lower jaw model 17' with the digital support pins 18' of the digital upper jaw model 16'. For this purpose, in a step j) the digital upper jaw model 16' and the digital lower jaw model 17' are matched in advance, optionally taking into account the at least one digital vestibular model, such that the CAD-CAM program records the relative position between the digital upper jaw model 16' and the digital lower jaw model 17'. This results in the dimensions and positions of the digital support pins 18' of the digital lower jaw model 17'.

In a further step k), the dental prosthesis 19 is designed using the CAD-CAM program by creating a digital dental prosthesis model 19', in the present case in the form of a 10a to 10f shown lower jaw posterior tooth prosthesis.

Now, in step I), the designed dental prosthesis 19 is produced using the digital dental prosthesis model 19', in particular by means of printing and/or milling and/or grinding. To do this, the CAD-CAM program creates control commands in a known manner, which are forwarded to a suitable processing machine.

In order to test and, if necessary, optimize the accuracy of fit of the manufactured dentures 19, in a further step m) based on the 7 digital maxillary model 16' shown, equipped with the digital support pins 18' and based on the 8 shown, provided with digital support pins 18', an upper jaw model 16 with support pins 18 and a lower jaw model 17 with support pins 18 are manufactured, in particular also by means of printing and/or milling and/or grinding.

Subsequently, in step n), the upper jaw model 16 and the lower jaw model 17 are fixed in an articulator 9, which has bases 20 arranged on a height adjustment device 12. The number, positions, shapes and orientations of the bases 20 provided on the articulator 9 correspond to the number, positions, shapes and orientations of the scan markers 10 positioned on the transfer table 8. Furthermore, the height adjustment devices 12 also correspond to one another in the present embodiment. In a first sub-step, the height of the height adjustment device 12 of the articulator 9 is set such that it corresponds to the height of the height adjustment device 12 of the transfer table 8 in the state in which the digital transfer table model 15' was recorded. In a further sub-step, the support pins 18 of the upper jaw model 16 are placed on the bases 20 of the articulator 9, see the 12a to 12e . The upper jaw model 16 can now be connected to the articulator 9. To do this, the space 21 between the upper jaw model 16 and a spacer plate 22 arranged on the top of the articulator 9 is filled with a plaster-like hardening mass which holds the upper jaw model 16 firmly to the spacer plate 22 after hardening. In a further sub-step, the height adjustment device 12 is then lowered and, in this case, removed from the articulator 9. The support pins 18 of the lower jaw model 17 are then placed from below onto the support pins 18 of the upper jaw model 16, whereupon the lower jaw model 17 is also connected to the bottom of the articulator 9 using a plaster-like mass. The support pins 18 can now be removed if they hinder the testing of the accuracy of fit of the manufactured dentures 19.

A further variant of the method according to the invention is described in the 13 and 14 shown. In this variant, adapter plates 23 are calculated in the CAD-CAM program depending on the relative position between the digital scan markers 10' on the one hand and the digital lower jaw model 17' and the digital upper jaw model 16' on the other hand and with knowledge of the geometry of the articulator 9, with which the manufactured upper and lower jaw models 16, 17 can be releasably attached to fastening devices 24 of the articulator 9. The adapter plates 23 and the fastening devices 24 are provided with interlocking sections, not shown in detail here, which align the adapter plates 23 when they are arranged on the fastening devices 24. The releasable fixation of the adapter plates 23 to the fastening devices 24 can be carried out, for example, via snap connections, magnetic connections or the like. Prefabricated, reusable spacer plates 22 can be positioned between the adapter plates 23 and the fastening devices 24 in order to save material when producing the adapter plates 23. The calculated adapter plates 23 are digitally added to the digital upper and lower jaw models 16', 17' and manufactured in step m) together with the upper jaw model 16 and the lower jaw model 17. The upper jaw model 16 and the lower jaw model 17 can then be attached to the fastening devices 24 of the articulator 9 via the adapter plates 23, as shown in the 13 and 14 is shown. In this case, it is not necessary to equip the articulator 9 with a height adjustment device 12 and with bases 20. There is also no need to fix the upper jaw model 16 and the lower jaw model 17 to the articulator 9 using the plaster-like material.

In principle, it would also be possible to produce a simple articulator together with the upper jaw model and the lower jaw model, i.e. to produce it using 3D printing, but this is very time-consuming due to the printing speed of today's 3D printers.

The present invention is characterized in particular by the fact that with the indirect CAD-CAM method, there is no need to give the dental technician plaster models of the patient's upper and lower jaws and the holding device 5 with the bite fork 4 held thereon and having the bite impression 6, which the dental technician can insert into a conventional articulator to check the accuracy of fit of a designed and manufactured dental prosthesis 19. Instead, the dentist can digitally transmit all the information required to manufacture and test the dental prosthesis 19 to the dental technician, which saves time and money. The transfer table 8 used by the dentist to create the digital transfer table model 15' simulates the articulator 9 used by the dental technician and enables the digitization of the patient-specific parameters recorded via the facebow 3 at the dentist, which are required for the later insertion of the upper and lower jaw models 16, 17 into an articulator 9.

It should be clear that the previously described embodiments serve only as examples and are not intended to limit the scope of protection of the present application. Rather, changes and/or modifications are possible without departing from the scope of protection defined by the appended claims. For example, the manufacture of support pins 18 can also be dispensed with in whole or in part if the lower jaw model 17 is in a clear position can be manually attached to the upper jaw model 16 from below.

REFERENCE NUMBER LIST

1

Head

2

Oral scanner

3

Facebow

4

Bite fork

5

Holding device

6

Bite impression

7

Bracket

8

Transfer table

9

Articulator

10

Scanmarker

11

projection

12

Height adjustment device

13

Height marking

14

transition

15

digital transfer table model

16

Upper jaw model

17

Lower jaw model

18

Support pin

19

dentures

20

base

21

Space

22

Spacer plate

23

Adapter plate

24

Fastening device

Claims (15)

CAD-CAM method for designing and producing dental prostheses (19) in the form of a crown, bridge, dental prosthesis or the like, which comprises the following steps: a) providing a computer system from which a dental CAD-CAM program can be used, which is designed for designing and producing dental prostheses (19) and includes a virtual articulator; b) creating a digital lower jaw model (17'), a digital upper jaw model (16') and optionally at least one digital vestibular model by scanning the oral cavity of a patient, wherein the digital models can be processed by the CAD-CAM program; c) recording the positional relationship of the upper jaw to the jaw joints and the skull base of the patient using a facebow (3) on which a bite fork (4) coated with an impression material is held via a holding device (5) detachably attached to the facebow (3); d) positioning the holding device (5) detached from the facebow (3) and the bite fork (4) held thereon, which now has a bite impression (6), on a holder (7) of a transfer table (8) on which at least one three-dimensional scan marker (10) is arranged; e) optionally forming a transition (14) from the at least one scan marker (10) to the bite fork (4) using a soft, elastic material; f) creating a digital transfer table model (15') which contains the positional relationship between the bite impression (6) and the at least one scan marker (10) by scanning the arrangement; g) transmitting the digital models created in step b) and the digital transfer table model (15') recorded in step f) to the computer system; h) Matching the at least one scan marker (10') contained in the digital transfer table model (15') with at least one digital scan marker of the virtual articulator stored in the CAD-CAM program, the position, shape and orientation of which corresponds to the position, shape and orientation of the at least one scan marker (10) positioned on the transfer table (8), such that the CAD program records the relative position between the digital bite impression (6') of the digital transfer table model (15') and the at least one digital scan marker (10') of the CAD-CAM program; i) Matching the digital bite impression (6') of the digital transfer table model (15') with the digital upper jaw model (16') such that the CAD-CAM program records the relative position between the digital upper jaw model (16') and the digital bite impression (6'); j) matching the digital upper jaw model (16') and the digital lower jaw model (17'), optionally taking into account the at least one digital vestibular model, such that the CAD-CAM program records the relative position between the digital upper jaw model (16') and the digital lower jaw model (17'); k) digitally designing the dental prosthesis (19) using the CAD-CAM program to create a digital dental prosthesis model (19') and i) producing the designed dental prosthesis (19) using the digital dental prosthesis model (19'), in particular by means of printing and/or milling and/or grinding. Procedure according to Claim 1 , based on the digital maxillary model (16') and In a step m), an upper jaw model (16) and a lower jaw model (17) are produced from the digital lower jaw model (17'), in particular by means of printing and/or milling and/or grinding. Procedure according to Claim 2 , in which the upper jaw model (17) and the lower jaw model (17) are fixed in an articulator (9) in a step n) taking into account the relative positions recorded in steps h) to j). Procedure according to Claim 3 , in which a plurality of scan markers are provided distributed on the transfer table and on the virtual articulator, the positions, shapes and orientations of which correspond to one another, the digital upper jaw model in the CAD program is provided with digital support pins (18') after matching, which connect the digital upper jaw model (16') to the digital scan markers (10'), the upper jaw model (16) is produced including the support pins (18), the support pins (18) are placed on bases (20) of the articulator (9), the respective positions, shapes and orientations of which correspond to the scan markers (10) positioned on the transfer table (8); and the upper jaw model (16) is fixed in this position on the articulator (9). Procedure according to Claim 4 , in which the lower jaw model (17) is placed against the upper jaw model (16) fixed to the articulator (9) and fixed in this position to the articulator (9). Procedure according to Claim 4 , in which the digital lower jaw model (17') in the CAD-CAM program is provided with digital support pins (18') which connect the digital lower jaw model (17') with the digital support pins (18') of the digital upper jaw model (16'), the lower jaw model (17) is produced including the support pins (18), the support pins (18) are placed in the articulator (9) on the support pins (18) of the upper jaw model (16) already fixed in the articulator (9), and the lower jaw model (17) is fixed in this position on the articulator (9). Method according to one of the preceding claims, in which the at least one scan marker (10) provided on the transfer table (8) is height-adjustable via a height adjustment device (12), wherein the height adjustment device (12) has a display device on which the set height can be read and/or a height marking (13) representing the set height, which is also scanned in step f) when creating the digital transfer table model (15'), and in which the articulator (9) has a height adjustment device (12) which preferably corresponds to the height adjustment device (12) of the transfer table (8). Procedure according to Claim 7 , in which the height of the at least one scan marker (10) provided on the transfer table (8) is adjusted in step d) via the height adjustment device (12) such that this (10) is positioned close to the underside of the bite fork (4). Procedure according to one of the Claims 3 until 8 , characterized in that in order to bridge a distance between the upper and lower jaw models (16, 17) positioned on the articulator (9) with proper consideration of the occlusal plane and fastening devices (12) formed on the articulator (9) for receiving the upper jaw model (16) and the lower jaw model (17), adapter plates (23) are calculated in the CAD program, which are supplemented on the digital upper and lower jaw models (16, 17) and with which the upper jaw model (16) and the lower jaw model (17) are produced in step m). Procedure according to Claim 9 , in which the adapter plates (23) and the fastening devices (24) have positively interlocking sections which align the adapter plates (23) when arranged on the fastening devices (24). Articulator (9) and transfer table (8) geometrically matched to the articulator (9) for carrying out a method according to one of the preceding claims, characterized in that the transfer table (8) has a holder (7) for receiving a removable joint piece (5) of a face bow (3) and at least three three-dimensional scan markers (10) are positioned on the transfer table (8), and that at least three bases (20) are positioned on the articulator (9), the respective positions, shapes and orientations of which correspond to the scan markers (10) positioned on the transfer table (8). Articulator (9) and transfer table (8) after Claim 11 , characterized in that the scan markers (10) provided on the transfer table (8) are jointly height-adjustable via a height adjustment device (12), wherein the height adjustment device (12) has a display device on which the set height can be read and/or a height marking (13) representing the set height, and that the bases (20) provided on the articulator (9) are jointly height-adjustable via a height adjustment device (12) analogously to the scan markers (10) provided on the transfer table (8), wherein the height adjustment device (12) has a display device on which the set height can be read and/or a height marking (13) representing the set height. A computer program comprising instructions which, when executed on at least one computer, cause the at least one computer to perform the steps of the method according to one of the Claims 1 until 10 to carry out. A computer-readable medium comprising instructions which, when executed on at least one computer, cause the at least one computer to perform the steps of the method according to any one of Claims 1 until 10 to carry out. Apparatus for data processing, comprising a processor and a data storage device on which computer-executable program code is stored which, when executed by the processor, causes the processor to carry out the steps of the method according to one of the Claims 1 until 10 to carry out.