DE102017002618B4 - Method and device for producing a toothed ring model - Google Patents

Abstract

Method for producing a system consisting of a dental arch model (3) for dental modeling and a carrier plate (1,16,19), the dental arch model (3) on the carrier plate (1,16,19) in a final position intended for modelling Position can be arranged reversibly by means of several guide pins (8,21) to be arranged on the carrier plate (1,16,19), which engage in receiving holes (6,11) of the toothed ring model (3), forming a sliding guide, comprising the steps: Intraoral scanning of a patient's row of teeth and generation of corresponding scan data;- Importing the scan data into a CAD/CAM program, the CAD/CAM program storing a data record of the carrier plate (1,16,19) for the virtual three-dimensional representation of this carrier plate (1st ,16,19);- generating a three-dimensional representation of a virtual toothed ring model (3) based on the scan data in the CAD/CAM program;- aligning the virtual toothed ring model (3) relative to the virtual carrier plate (1,16,19) in the desired final position; - Defining a distribution of virtual receiving holes (6,11) for the guide pins (8,21) in the virtual sprocket model (3) and/or in the virtual carrier plate (1,16,19) in this final position;- generating a data record based on the alignment of the virtual gear ring model (3) relative to the virtual carrier plate (1,16,19) and the determination of the distribution of the mounting holes (6 ,11);- Using this data set to produce a physical toothed model (3) by means of an additive manufacturing process; characterized by the further steps:- after aligning the virtual gear ring model (3) relative to the virtual carrier plate (16) in the desired final position, defining a virtual fastening structure consisting of outwardly protruding, rod-shaped fastening elements (13) on the virtual gear ring model ( 3) which are aligned and designed in such a way that they can interact with corresponding fastening elements (14) which are provided on a holder (15) of a pin drilling device for the physical support plate (16); and- producing physical fastening elements (13) together with the physical toothed ring model (3) on the basis of the virtual fastening elements (13) by the additive manufacturing process.

Description

The present invention relates to a method and a device for producing a system consisting of a dental arch model and a carrier plate, on which the dental arch model is placed in a position intended for dental modeling by means of a plurality of guide pins (pins) to be arranged on the carrier plate, forming a sliding guide engage in receiving holes of the toothed ring model, can be arranged reversibly.

Different systems are known from the prior art, consisting of a toothed ring model and a base or carrier plate that supports it. A dental arch model to be modeled, e.g. made of plaster, is always mounted detachably on the base plate by means of pins or guide pins, so that a dental technician can subsequently carry out dental processing steps, e.g. in an articulator. In a classic procedure, the dental arch model is obtained by taking an impression of the dentition with an elastic impression compound. The impression is then filled with super-hard plaster up to above the gum line and then, after the dental arch obtained in this way has hardened and ground completely smooth towards the base, it is drilled on a special drill stand (pin drilling device) precisely from the base side in such a way that the drill holes are basal in the tooth stumps and other parts of the jaw. Then pins are glued into the holes, with the diameters of the drill holes and the pins being matched so that the pins can be inserted and glued in with a perfect fit. After the dental arch has been isolated, the base is made of plaster of paris, whereby the dental arch model with the inserted pins is either placed directly into the plastic plaster of the base or the dental arch model is put back into the impression and the negative impression is completely poured out. The dental arch model can then be divided by sawing into corresponding model stumps or dental arch segments as required for the desired processing.

An alternative method uses a dimensionally and dimensionally stable plastic base plate. Before the impression is poured, the positions of the pins are determined and transferred to the base plate through conical drill holes, into which the pins are then inserted so that they cannot be lost. The dental arch model is then poured out and the "pinned" base plate is lowered into the plaster mass. After the plaster has set, the impression can then be removed, the dental arch can be detached from the base plate and the desired dental arch segments can be sawn.

Irrespective of a precision impression or a ring impression with a collective impression, the dentist always has to carry out impression steps that are mechanically complex and possibly uncomfortable for the patient using various impression materials, which also entail subsequent cleaning steps in the oral cavity. For these reasons, the use of non-contact scanning methods is increasing.

If a dentist no longer forms the rows of teeth in the conventional way with impression material and tray, but uses a so-called intra-oral scanner, he only generates a three-dimensional data set at the treatment chair.

On the basis of such a three-dimensional data set, with intermediate steps of various rendering processes, the dental arch model intended for further dental modeling work or individual dental arch segments can be milled or produced in a 3D printing process, i.e. additively. Such technology has been in use for years and is being further refined.

Furthermore, it is also already known to removably attach toothed segments that have been milled or additively (3D-printed) manufactured in this way, or also an entire toothed ring, to a carrier plate with pins or guide pins. After all, it is already common practice to removably attach milled or additively manufactured gear segments or an entire gear rim to an individually cast carrier plate using pins and guide sleeves.

In the professional world, it is undisputed that it is estimated that in less than a decade the so-called "model-less approach", i.e. the production of dentures without an actual physical jaw model obtained by means of an impression, for example, will represent the standard for simpler forms of care. For cost reasons alone, various bridging technologies will pave the way there, because at the moment not all work steps in dental technology, from dentist to dental technician, can be digitally mapped and the data received can be processed accordingly. The articulation in particular, with all its individual patient-related features, requires not only human experience and skill, but also a physical jaw model, preferably set in an articulator.

Where in classical dentistry, dental impressions are still made with so-called impression trays, these are then, as mentioned above, filled with a plaster material and then be ground, drilled and "pinned" to ultimately produce such a jaw or dental arch model, the digital technologies require a fundamentally different workflow.

In the digital workflow, the 3D intraoral scanner replaces the impression tray. The scanner allows non-contact scanning of the jaw and uses its computing unit to generate a virtual 3D model of the entire lower or upper jaw, the corresponding rows of teeth or even just individual sections. This data is already being used today to print or mill jaw models or dental arch models using CAD/CAM processes.

However, the printed model systems currently on the market are in many respects inferior to conventional plaster models. For example, a model with removable segments (tooth stumps) is required to obtain optimal access from all sides to the circular stump preparation line. However, these segments must be able to be repositioned many times after they have been removed. It depends on low tolerances and good handling. The segments must be held securely in their base, but at the same time run smoothly in their guidance. Finally, the dental technician must be able to see whether the segment sits on the base without a gap.

State-of-the-art is currently a method in which the printed dental arch is drilled on a conventional pin drilling device, for example according to Zeiser ^® , for plaster models and then fitted with pins. In the final step, this model is then classically based in plaster (so-called Pindex method). This method is more of a makeshift than a really workable solution.

With the Zeiser ^® type model system, a base plate made of plastic is used, which is drilled using a device and then fitted with pins. To put it simply, the dental arch made of plaster of paris is poured onto it. The pins are held securely in the plaster material by their retentive structure in the upper part. The finished model can be sawn and the toothed segments repositioned many times quickly and easily.

Costs always play an important role in medical technology. In dental laboratories in particular, the technical equipment is a significant cost factor, which is why it is important to use it as optimally and for as long as possible.

In addition, various methods for the preferably additive production of toothed ring models with the aid of CAD/CAM technology are already known from the prior art, such as these, for example, in the publications DE 10 2013 204 146 A1 , EP 2 345 387 A2 , U.S. 2013/0041630 A1 and U.S. 2008/0015727 A1 are revealed.

The object of the present invention is therefore to provide another method for producing a system consisting of a toothed ring model and a support plate provided for this purpose for the purpose of dental modeling work.

This object is achieved with a method for producing such a system according to claim 1 and with a device according to claim 8.

• - intraorales Scannen einer Zahnreihe eines Patienten und Generieren von entsprechenden Scandaten;
• - Importieren der Scandaten in ein CAD/CAM-Programm, wobei das CAD/CAM-Programm einen Datensatz der Trägerplatte zur virtuellen dreidimensionalen Darstellung dieser Trägerplatte enthält;
• - Generieren einer dreidimensionalen Darstellung eines virtuellen Zahnkranzmodells auf Basis der Scandaten in dem CAD/CAM-Programm;
• - Ausrichten des virtuellen Zahnkranzmodells relativ zu der virtuellen Trägerplatte in der gewünschten finalen Position;
• - Festlegen einer Verteilung von virtuellen Aufnahmelöchern für die Führungsstifte in dem virtuellen Zahnkranzmodell und/oder in der virtuellen Trägerplatte in dieser finalen Position;
• - Generieren eines Datensatzes auf Basis der erfolgten Ausrichtung des virtuellen Zahnkranzmodells relativ zu der virtuellen Trägerplatte und der Festlegung der Verteilung der Aufnahmelöcher; und
• - Verwenden dieses Datensatzes zur Herstellung eines physischen Zahnkranzmodells im Wege eines additiven Herstellungsverfahrens.

In one aspect, the invention relates to a method for producing a system consisting of a dental arch model for dental modeling and a carrier plate, the dental arch model being held on the carrier plate in a final position provided for the modeling by means of a plurality of guide pins (pins) to be arranged on the carrier plate. which engage in receiving holes of the toothed ring model, forming a sliding guide, can be arranged reversibly, having the steps:

• - Intraoral scanning of a row of teeth of a patient and generation of corresponding scan data;
• - Importing the scan data into a CAD/CAM program, the CAD/CAM program containing a data record of the carrier plate for the virtual three-dimensional representation of this carrier plate;
• - Generating a three-dimensional representation of a virtual toothed ring model based on the scan data in the CAD/CAM program;
• - aligning the virtual toothed ring model relative to the virtual carrier plate in the desired final position;
• - Specifying a distribution of virtual receiving holes for the guide pins in the virtual sprocket model and/or in the virtual carrier plate in this final position;
• - Generating a data record based on the alignment of the virtual gear model relative to the virtual carrier plate and the determination of the distribution of the receiving holes; and
• - Using this dataset to produce a physical dental arch model via an additive manufacturing process.

An alignment of the virtual dental arch model, which is carried out on the screen of a computer, refers on the one hand to the height that the printed dental arch model or the chewing surface should then have in relation to the base or carrier plate, but on the other hand also to the angular alignment relative to a center or relative to a line of symmetry of the backing plate. Another criterion that is included in the alignment process in connection with the determination of the positions and the distribution of the mounting holes concerns the fact whether the carrier plate actually to be used later for the arrangement of the physical gear model, whose data set would then have to be taken into account accordingly, already has one distribution or matrix of location holes for the guide pins, or whether these have to be drilled later after the physical gear model has been produced on the basis of the digital data.

In addition, the selection of the segments and thus the determination of the saw cuts for the alignment process is crucial, which in turn interacts with the positions to be determined of the mounting holes and/or the existing or yet to be made mounting holes for the guide pins.

Accordingly, in one embodiment, the receiving holes can already be produced in the physical toothed ring model during the additive manufacturing process.

Such milled or additively manufactured sprockets are subject to the usual production-related tolerances and have a relatively rough surface due to their layered production on the one hand and due to the material used, compared to e.g. plaster of paris. The consequence of this is that the receiving holes in the toothed ring intended for the guide pins are also subject to the usual production-related tolerances and material deficiencies and can have a rough inner surface that is therefore not very easy to slide for the guide pins.

Due to the roughness of these inner surfaces and the factors mentioned above, smooth sliding and constant friction are technically not possible. It can therefore also happen that when a toothed ring model is detached from its carrier plate, the guide pins “cant” or get stuck in the mounting holes and are thus pulled out of the carrier plate, so that the entire system becomes unusable.

One way to counteract this would be to mechanically rework the inner surfaces of the receiving holes, which would, however, generate additional costs and still not provide a uniform quality.

This manufacturing and/or material-related rough inner surface of each receiving hole can, however, be designed to be easy to slide with the aid of a sleeve for the guide pins that is introduced into the receiving hole with a tight fit. The inner diameter of the receiving holes on the one hand and the outer diameter of the sleeves on the other hand are designed with such tolerances that such an adhesive or press fit can be achieved that always ensures a secure hold for subsequent dental processing steps and is also preferably designed in such a way that a Dental technician can press this sleeve only by manually applied force. Ideally, the material of the toothed ring model can have a certain, albeit low, flexibility for this purpose. It is also conceivable that the sleeves for receiving the guide pins (pins), which are usually made of brass in the prior art, can also have a certain flexibility in order to provide a compensation option.

Furthermore, the sleeve and the pins can form a pair of materials in order to provide different degrees of hardness for guiding the pins in the sleeves, depending on the application. Both guide pins and sleeves can be made from a plastic that is selected from the group consisting of polyethylene, polypropylene, polyamide, polypropylene (copolymer) or polytetrafluoroethylene.

Alternatively, it is also conceivable that the gear ring model can be produced from at least one, preferably from at least two, different materials using an additive manufacturing process, with the material or at least one material for the guide pins having defined sliding properties.

Some additive manufacturing processes (3D printing), such as fused deposition modeling (FDM), allow composites to be formed from multiple materials. So it is conceivable to form the upper area of the dental arch intended for the dental modeling from a generally harder material suitable for such modeling work, while the lower area, in which the receiving holes are made, from a somewhat softer material, for example a Polypropylene present in filament form, which provides better sliding properties for guiding the pins.

In this context, it is also conceivable that the gear rims are additively manufactured from one or more high-performance plastics with similar sliding properties by selective laser sintering or by stereolithography.

A further improvement in the guiding or sliding properties for the pins is achieved in that, if no sleeve is to be used, the inner surface of the receiving holes have surface structures which enter into at least a three-point bearing with the guide pins.

In this context, the invention proposes that guide elements for the guide pins are also produced in the additive manufacturing process, with the guide elements forming such surface structures.

In one embodiment, such a three-point bearing can be realized by forming the surface structures from radially inwardly directed elevations, such as conical, spherical, wart-shaped or similar configurations. The elevations are preferably designed as three equidistant longitudinal ribs.

In a preparatory step, these virtual guide elements are "inserted" into the mounting holes of the virtual gear model on the computer or aligned in the course of generating the entire 3D gear model.

The physical guide elements, e.g. longitudinal ribs, can then, as mentioned above, be printed out of a material that has better sliding properties, while the base body of the gear ring model consists of a different material, with production preferably taking place using the FDM process mentioned above .

• - nach dem Ausrichten des virtuellen Zahnkranzmodells relativ zu der virtuellen Trägerplatte in der gewünschten finalen Position, Festlegen einer virtuellen Befestigungsstruktur bestehend aus nach außen abragenden, stabförmigen Befestigungselementen an dem virtuellen Zahnkranzmodell, die mit Befestigungselementen einer Halterung eines Pinbohrgeräts für die physische Trägerplatte korrespondieren; und
• - Herstellen von physischen Befestigungselementen zusammen mit dem physischen Zahnkranzmodell auf Basis der virtuellen Befestigungselemente durch das additive Herstellungsverfahren.

The method according to the invention is characterized by the further steps:

• - After aligning the virtual sprocket model relative to the virtual support plate in the desired final position, setting a virtual attachment structure consisting of outwardly protruding, rod-shaped fasteners on the virtual sprocket model, which correspond to fasteners of a holder of a pin drilling device for the physical support plate; and
• - Manufacture of physical fasteners together with the physical gear model based on the virtual fasteners through the additive manufacturing process.

• - Festlegen von virtuellen Versteifungselementen an dem virtuellen Zahnkranzmodell; und
• - Herstellen von physischen Versteifungselementen zusammen mit dem physischen Zahnkranzmodell auf Basis der virtuellen Versteifungselemente durch das additive Herstellungsverfahren.

In yet another embodiment of the method according to the invention, this has the step:

• - Defining virtual stiffening elements on the virtual toothed ring model; and
• - Manufacture of physical stiffening elements together with the physical gear ring model based on the virtual stiffening elements using the additive manufacturing process.

The fastening elements allow the physical dental arch model, once it has been produced, to be positioned exactly and without errors on a corresponding holder or clamping device for the carrier plate of a state-of-the-art pin drilling device that may already be available in the laboratory for drilling the receiving holes.

The stiffening elements also serve to ensure that the dental arch model does not twist or deform during the drilling process or sawing of the segments or, if necessary, further dental processing steps, which would lead to errors.

Both the fastening elements and the stiffening elements can then be removed from the toothed ring model in a simple manner, for example with a saw, after all the cuts for the segment formation and all the receiving holes for the guide pins have been formed or made.

In this context, the invention therefore also relates to a device for producing receiving holes in a physical sprocket model, in which the sprocket model can be produced by means of an additive manufacturing process together with a fastening structure consisting of outwardly protruding, rod-shaped fastening elements on the sprocket model, having a holder for a Carrier plate on which the dental arch model can be arranged for dental modelling, the holder or clamping/clamping device for the carrier plate having fastening elements which interact with the fastening elements of the dental arch model, preferably in a form-complementary or form-fitting and/or non-positive manner. Ideally, the fastening elements of the bracket and the fastening elements of the toothed ring model form a captive locking connection.

In a preferred embodiment according to the invention, the method is characterized in that the locating holes to be provided in the physical sprocket model and/or locating holes to be provided in the physical carrier plate for the guide pins are drilled on the basis of the positions resulting from the specified distribution of the virtual locating holes. This can be done using a corresponding pin drilling device that is already available.

Preferably, the drilling of the mounting holes in the support plate and the mounting holes in the sprocket model takes place at the same time, i.e. when the sprocket model has been arranged on the support plate and fixed by means of the fastening elements in relation to the clamping device for the support plate, a stepped bore can be carried out so that the receiving or through holes in the support plate have a larger diameter than the receiving holes in the gear model.

The shape of the through-holes can also vary. Thus, the through bores can widen downwards to accommodate a fastener for the guide pins in relation to the diameter of the guide pins. After the pins have been inserted into the through-holes from above according to the desired positioning for the model of the sprocket, the fasteners can be inserted from below, more or less from the back.

This can be designed, for example, as a purely mechanical means, such as a clamping ring that forms a latching mechanism with the pin and engages in the widening of the through hole as a press fit. Ideally, however, the fastening means is an adhesive that is introduced into the extension and, after curing, fixes the guide pins in the through-holes.

For this purpose, the guide pins can also have at least one radial groove for receiving the adhesive in their axial course. Such radial grooves form an undercut to open the through bores, so that the adhesive anchors the guide pin captively after curing has taken place.

Acrylic-based materials are suitable as adhesive, preferably a light-curing acrylate, so that the dental technician can fasten the pins in their final position by simply irradiating (UV light) the back of the carrier plate.

Through holes are preferably formed with a defined oversize in relation to the diameter of the guide pins, so that they can align themselves in the best possible position, quasi automatically, when inserted into the receiving holes of the toothed ring model. After this calibration, the guide pins can be fixed by means of the adhesive. This has the advantage that the mounting holes in the gear ring model do not have to be manufactured with great precision, either by subsequent drilling or by means of 3D printing.

• - Ausbilden von Durchgangsbohrungen in der Trägerplatte;
• - Einfügen von Führungsstiften in die Durchgangsbohrungen;
• - Ausrichten des Zahnkranzmodells gegenüber der Trägerplatte beim Anordnen des Zahnkranzmodells auf der Trägerplatte, wenn die Führungsstifte der Trägerplatte in Aufnahmelöcher in dem Zahnkranzmodell gleitend aufgenommen werden; und
• - nach erfolgter Ausrichtung des Zahnkranzmodells gegenüber der Trägerplatte, Fixieren der Führungsstifte in den Durchgangsbohrungen mittels eines Befestigungsmittels.

Consequently, the method according to the invention also relates to the further steps that follow the production (3D printing) of the toothed ring model:

• - Forming of through holes in the support plate;
• - Insertion of guide pins in the through holes;
• - aligning the gear ring model with respect to the carrier plate when placing the gear ring model on the carrier plate when the guide pins of the carrier plate are slidably received in receiving holes in the gear ring model; and
• - After alignment of the toothed ring model in relation to the carrier plate, fix the guide pins in the through-holes using a fastener.

For this purpose, the inside diameters of the through bores preferably have a defined oversize in comparison to the outside diameter of the guide pins.

The guide pins are fixed from the side of the carrier plate that is opposite the toothed ring model, by gluing with a light-curing acrylate, for example. It is also conceivable, however, for the guide pins to be melted into or fused with the carrier plate by the targeted action of heat.

By the dental technician positioning the guide pins with a certain amount of play in the through holes of the carrier plate on the one hand and in the receiving holes or in the sleeves of the dental arch model inserted in them on the other hand, so that a certain axial, radial and tilting compensation is made possible, the selected combination of guide pins can be adjusted , if necessary, calibrate the sleeves and dental arch model as well as the carrier plate in a simple manner before the final fixation is carried out.

The invention is distinguished by the fact that equipment that already exists and is used in a laboratory, such as pin drilling devices, can still be used, also in connection with upstream technologies for generating virtual dental models or models of teeth. The invention therefore combines novel digital processing methods with existing analog methods for processing physical gear models.

• 1 schematisch ein Ablaufdiagramm eines entsprechenden Verfahrens;
• 2 eine Trägerplatte zur Verwendung in einem solchen Verfahren;
• 3 schematisch eine perspektivische Ansicht eines auf der Trägerplatte positionierten und ausgerichteten Zahnkranzmodells;
• 4 eine Ansicht des Zahnkranzmodells von unten mit einer Anordnungsverteilung von Aufnahmelöchern;
• 5 schematisch eine perspektivische Ansicht der Montage eines ausgedruckten Zahnkranzmodells auf einer Trägerplatte;
• 6a eine Draufsicht auf ein aus einer Trägerplatte und einem Zahnkranzmodell bestehendes System;
• 6b einen Schnitt entlang A-A aus 6a;
• 6c eine vergrößerte Ansicht auf 6b;
• 7 schematisch ein Ablaufdiagramm eines weiteren Verfahrens;
• 8 schematisch eine Explosionsdarstellung der Montage bzw. virtuellen Ausrichtung eines ausgedruckten Zahnkranzmodells auf einer Trägerplatte;
• 9a eine Ansicht von unten, die die Lage von Pinführungselementen in den Aufnahmelöchern zeigt;
• 9b exemplarisch eine Ansicht zur Darstellung der dadurch realisierten Drei-Punkt-Lagerung;
• 10a ein zusammengebautes System aus Trägerplatte und Zahnkranzmodell im Teilschnitt;
• 10b eine vergrößerte Ansicht aus 10a;
• 11 schematisch ein Ablaufdiagramm des erfindungsgemäßen Verfahrens;
• 12 schematisch die Darstellung im Rahmen eines CAD/CAM-Programms;
• 13 eine Explosionsdarstellung der Anordnung des Zahnkranzmodells mit Trägerplatte auf einer Halterung;
• 14. eine perspektivische Darstellung des auf der Halterung angeordneten Zustands;
• 15a eine Draufsicht auf diesen Zustand;
• 15b einen Schnitt entlang B-B aus 15a zur Darstellung der Stufenbohrung;
• 16 schematisch ein Ablaufdiagramm eines weiteren Verfahrens;
• 17a eine Draufsicht auf ein Zahnkranzmodell, das in dieser Ausführungsform auf einer Trägerplatte positioniert ist;
• 17b eine Schnittdarstellung entlang C-C aus 17a; und 17c eine vergrößerte Ansicht aus 17b.

Further advantages and features emerge from the description of the exemplary embodiments illustrated with the aid of the attached drawings. Show it

• 1 schematically a flow chart of a corresponding method;
• 2 a backing plate for use in such a method;
• 3 a schematic perspective view of a gear rim model positioned and aligned on the carrier plate;
• 4 a view of the sprocket model from below with an arrangement distribution of receiving holes;
• 5 schematically a perspective view of the assembly of a printed toothed ring model on a carrier plate;
• 6a a plan view of a system consisting of a carrier plate and a gear model;
• 6b cut along AA 6a ;
• 6c an enlarged view 6b ;
• 7 schematically a flow chart of a further method;
• 8th schematically an exploded view of the assembly or virtual alignment of a printed sprocket model on a carrier plate;
• 9a a bottom view showing the location of pin guide members in the receiving holes;
• 9b an example of a view showing the resulting three-point mounting;
• 10a an assembled system of carrier plate and toothed ring model in partial section;
• 10b an enlarged view 10a ;
• 11 schematically a flowchart of the method according to the invention;
• 12 schematic representation within the framework of a CAD / CAM program;
• 13 an exploded view of the arrangement of the ring gear model with support plate on a bracket;
• 14 . a perspective view of the state arranged on the holder;
• 15a a plan view of this state;
• 15b make a cut along BB 15a to show the stepped bore;
• 16 schematically a flow chart of a further method;
• 17a a top view of a sprocket model, which is positioned on a support plate in this embodiment;
• 17b a sectional view along CC 17a ; and 17c an enlarged view 17b .

1 FIG.

In a first step S1, the dentist uses an intraoral scanner to scan the corresponding rows of teeth in the jaws and generates a corresponding 3D data set. The data generated in this way is imported into a CAD/CAM program that is designed to generate a three-dimensional virtual toothed ring model based on this data (step S2). For the purposes of the present invention, a toothed ring model is to be understood as meaning both complete rows of teeth of the entire jaw and individual sections or individual teeth.

The CAD/CAM program already contains a number of data sets, each of which corresponds to base or support plates 1 of different design. Such a carrier plate 1 is exemplified in 2 shown. The carrier plate 1 already has a matrix or, in this case, a uniform distribution of a plurality of receiving bores 2 for receiving the guide pins.

In the CAD/CAM program, this carrier plate 1 is also displayed virtually together with the matrix of the mounting holes 2 .

In a further step S3, a user, for example a dental technician, now specifies the height of the virtual toothed ring model 3. The determination of the height is necessary in order to have enough material available for the dental modeling work to be carried out for the subsequent printing by means of a rapid prototyping process to have. In the figures, the toothed ring model 3 is shown schematically with flat surfaces, but in reality it naturally has the contours of the teeth and chewing surfaces corresponding to the jaw scan.

After determining the height, the dental technician positions the virtual dental arch model 3 on the virtual carrier plate 1 and aligns it with respect to the carrier plate 1 in such a way that a final position is assumed depending on the specified distribution matrix of the mounting holes 2 (step S4). This is an example in the 3 shown.

In this position, the dental technician then defines the distribution and number of the desired segments 4, as a result of which the cuts 5 are determined for the sawing work to be carried out later (step S5).

Again depending on this, the pin positions are then defined in a subsequent step S6 and the receiving holes 6 to be provided are represented virtually. An example is such a selected distribution of the receiving holes 6 in the 4 to see.

If the virtual gear rim model 3 is positioned in its final relative position in relation to the virtual carrier plate 1 and if the distribution of the virtual mounting holes 6 on the one hand and the virtual cuts 5 on the other hand has been determined, a corresponding data set is generated on the basis of this (step S7), so that the Sprocket model 3 can be produced from a suitable material in this form by means of an additive manufacturing process (3D printing) (step S8).

Depending on the quality of the manufacturing process, cleaning work or mechanical post-processing steps may follow.

In a further step S9, sleeves 7 are then inserted and fastened into the receiving holes 6 of the printed toothed ring model 3 for guiding guide pins (pins) 8, as is shown schematically in FIG 5 is shown.

The guide pins 8 have the task of ensuring an exact repositioning of the toothed ring model 3 or a toothed segment on the carrier plate 1 at any later point in time.

Since the toothed ring model 3 was produced entirely in an additive or machining process, its surface therefore has a certain roughness due to the material and production, which also applies to the inner surface of the receiving holes 6 . A rough inner surface, in turn, counteracts a smooth sliding of the guide pins 8 and also prevents constant friction. This entails the risk that when the ring gear 3 is loosened or lifted off the carrier plate 1, the guide pins 8 will be pulled out of the carrier plate 1 instead of from the ring gear model 3, which would make the carrier plate 1 unusable and increase the reject rate.

In order to avoid such an error, according to the invention, a preferably thin-walled sleeve 7 is introduced into the receiving hole 6 with a snug fit.

The resulting lining of the rough inner surface of the receiving hole 6 ensures that the guide pin 8 slides in and out of its receiving hole 6 with ease and at the same time compensates for the usual production-related tolerances of the ring gear 3 and the carrier plate 1 . Pulling out of the pin 8 from the support plate 1 can thus be avoided with the simplest of means.

The advantage of using such sleeves 7 is, among other things, that existing guide pins or pins from various manufacturers can still be used, even if the dental arch model 3 is designed using a new type of additive manufacturing process and not as a plaster mold.

In the 6a until 6c the system can be seen in the assembled state.

The guide pins 8 are inserted into the stepped through bores 2 from the underside, i.e. the side of the carrier plate 1 opposite the toothed ring model 3 . In the simplest form, these can form a press fit.

The sliding sleeves 7 are pressed into the receiving holes 6, forming a tight fit and thus enable the guide pins 8 to slide with reduced friction, so that a dental technician can lift the dental arch model 3 or segments 4 of the dental arch model 3 produced by corresponding saw cuts 5 at any time and attach them again without great effort originally intended positions can position. At the same time, the dimensions of the sleeve 7 and the guide pins 8 are selected in such a way that a captive positioning of the toothed ring model 3 or segments 4 is ensured for further dental modeling work.

In the embodiment shown, the guide pins 8 have a rear flange 9, which engages in an extension 10 of the through hole 2 in such a way that the guide pins 8 cannot be inadvertently pulled off upwards. These guide pins 8 are therefore also suitable for designs in which they are to be guided directly into receiving bores 6 of the toothed ring model 3 without the interposition of sliding sleeves, which have less good sliding properties.

Finally, the finished toothed ring model 3, if necessary with its segments 4, is assembled on the carrier plate 1 (step S12) and is then available for the dental modeling (step S13).

It is possible for a dental technician to independently produce the toothed ring model 3 in his laboratory according to the previous steps; it is sufficient if the corresponding data sets are made available to him. However, since data records are generated, it is also possible for external service providers to produce and then deliver the entire system (dental model) consisting of the printed dental arch model 3 and carrier plate 1 for a dental technician.

In the 7 until 10b another method is shown as an example.

7 shows a flowchart for the method, with steps S1 to S5 being identical to those in the method described above.

In this embodiment, when aligning in the CAD/CAM program, step S14 follows, in which the virtual pin positions in the toothed ring model 3 that correspond to the position of the receiving holes 11 are defined. In contrast to the receiving holes 6, however, these receiving holes 11 are not intended for the direct receiving of sleeves or guide pins, but rather are intended for receiving or arranging pin guide elements. These receiving holes 11 therefore have a larger diameter.

Therefore, in step S15, the position and alignment of virtual pin guide elements 12 is defined on the screen, which in the present case are arranged as three equidistant longitudinal ribs running in the axial direction of the receiving hole 11 in the receiving holes 11, like the 9a shows. These longitudinal ribs 12 are designed to engage in a three-point bearing with the pins 8 in the physical state ( 9b) .

After the alignment has taken place, a data record (step S16) is generated for the subsequent rapid prototyping manufacturing process and made available, for example, to a 3D printer.

In the subsequent printing (step S17), a one-piece additive printing of two different materials takes place.

A first material A for the base body of the toothed ring model 3 has the appropriate properties for the modeling work and is therefore harder than the material B selected for the guide elements 12, which has better sliding properties to allow the guide pin 8 to slide in and out easily in its receiving hole 11 to ensure. Overall, this also significantly reduces the entire frictional contact area between these components, and the usual production-related tolerances of ring gear 3 and support plate 1 are compensated. Accidental pulling out of a guide pin 8, for example if it does not have an abutment in the form of a flange 9, can thus be avoided with certainty.

In the 8th the alignment process or the assembly of the gear ring model 3 is shown as an example. A user determines the position of the virtual receiving holes 11 in the virtual toothed ring model 3 again depending on the predetermined distribution matrix of the receiving bores 2 in the carrier plate 1 and the segments 4 and cuts 5 to be defined.

The physical support plate 1 is then fitted with the pins 8 in a corresponding manner (step S18), and the segments 4 of the toothed ring model 3 are then sawed (step S19).

As in the first embodiment, the dental model produced in this way is then available for further dental processing steps (steps S20 and S21).

In the 10a and 10b shows an example of the assembled physical state of the system made up of the carrier plate 1 and the printed gear model 3, with the three-point bearing of the guide pins 8 being clearly visible.

In the 11 until 15b an embodiment of the method according to the invention is shown, wherein 11 reflects the flow chart.

In this case, steps S1 to S4 are identical to the previous methods. In step S22, the user creates on the screen 12 (see Fig. 12 ) first a virtual attachment structure consisting of outwardly protruding, rod-shaped fasteners 13. The fasteners 13 are aligned and designed so that these can interact with corresponding fastening elements 14, which are provided on a holder 15 for a pin drilling device. Accordingly, the holder 15 with the fastening elements 14 is already stored in the CAD/CAM program as a data record for the virtual three-dimensional representation.

In this context, the invention also relates to a device for producing receiving holes in a physical gear ring model 3 and/or in a physical carrier plate 16, having a holder 15 for this carrier plate 16, the holder 15 having fastening elements 14 which are connected to the fastening elements 13 of the gear ring model 3 interact.

As the 13 and 14 12 show fasteners 13 and 14 cooperating by way of a mortise and tenon connection; the fastening elements 14 on the holder 15 are designed as pegs with such a tolerance that, on the one hand, the gear ring model 3 can be easily placed, but at the same time the gear ring model 3 is held captive and without the possibility of twisting for subsequent drilling work.

The holder 15, which is designed as a clamping device, serves to accommodate a further embodiment of a carrier plate 16, which itself does not yet have any mounting holes for pins.

Furthermore, in step S22 of the method according to the invention, a stiffening structure in the form of crossing struts 17 is generated virtually.

Any segments are then determined again (step S23) and then the data set for rapid prototyping is generated (step S24) and exported to the 3D printer, where the gear ring model 3 is then printed out in one piece together with the fastening and stiffening structure in a single printing process will.

The carrier plate 16 consisting of a solid material is then inserted into the holder 15 (step S26) and the printed toothed ring model 3 is attached to the fixing structure (pin 14) of the holder 15 (step S27). Thereafter, the entire structure consisting of holder 15, support plate 16 and toothed ring model 3 is inserted into a conventional pin drilling device (step S28). The dimensions for the holder 15 can be standardized for this.

In the pin drill is then with a step drill 18, the example in the 15b with the direction of action (arrow) being indicated, both the carrier plate 16 and the gear ring model 3 are drilled to form through-holes in the carrier plate 16 with a larger diameter and receiving holes in the gear ring model 3 with a smaller diameter (step S29).

The gear ring model 3 drilled in this way is then removed (step S30) and the fastening and stiffening structure is separated from the base body of the gear ring model 3 using suitable tools (step S31).

Thereafter, the carrier plate 16, which has also been drilled, is removed from the holder 15 (step S32). The guide pins are inserted into the receiving holes of the sprocket model 3 (step S33), any segments are sawn (step S34).

This is followed by the corresponding assembly again as a dental model and provision to a user (steps S35 and S36).

The advantage of this method is that the distribution of the mounting holes can be selected by the user as he sees fit in the light of the subsequent dental modeling work and the segment division provided for this purpose, without having to take into account a predetermined distribution matrix of mounting holes in the carrier plate . The mounting holes are consequently drilled individually.

In the 16 until 17c another method is shown.

Here, the steps S1 to S8 in the virtual space are identical to those in the first embodiment.

However, a carrier plate 19 is provided for this case, which has a matrix of mounting holes 20, the mounting holes 20 widen conically downwards, as in particular in FIG 17c you can see.

According to step S37, the guide pins 21, which are stepped (see 17c ), inserted into the mounting holes 6 of the printed gear model 3.

After that, the gear ring model 3 with the pins 21 is placed on the carrier plate 19 so that they engage in the mounting holes 20 (step S38). The mounting holes 20 are oversized compared to the diameter of the lower section of the guide pins 21, so that they are guided in the mounting holes 20 without friction. Accordingly, the guide pins 21 have a slight axial and radial Game that allows automatic alignment when merging and joining the gear ring model 3 with the support plate 19.

Due to the fact that the mounting bores 20 widen downwards, so that a gap 22 remains on the face side opposite the gear rim model 3 (see Fig. 17c ), it is possible to introduce a fastener, for example in the form of an adhesive (not shown), into the gap 22 in order to finally fix the guide pins 19 (step S39).

After the adhesive has hardened, the gear ring model 3 is removed from the carrier plate 19 (step S40), with the pins 21 remaining captively anchored in the carrier plate 19.

Then, as in the previous methods, the segments are formed (step S41), the dental model is completed (step S42) and handed over to a user for further dental modeling (step S43).

Claims (9)

Method for producing a system consisting of a dental arch model (3) for dental modeling and a carrier plate (1,16,19), the dental arch model (3) on the carrier plate (1,16,19) in a final position intended for modelling Position can be arranged reversibly by means of several guide pins (8,21) to be arranged on the carrier plate (1,16,19), which engage in receiving holes (6,11) of the toothed ring model (3), forming a sliding guide, comprising the steps: intraorally scanning a row of teeth of a patient and generating corresponding scan data; - Importing the scan data into a CAD/CAM program, the CAD/CAM program containing a data record of the carrier plate (1,16,19) for the virtual three-dimensional representation of this carrier plate (1,16,19); - Generating a three-dimensional representation of a virtual toothed ring model (3) on the basis of the scan data in the CAD/CAM program; - Aligning the virtual sprocket model (3) relative to the virtual support plate (1,16,19) in the desired final position; - Defining a distribution of virtual receiving holes (6,11) for the guide pins (8,21) in the virtual sprocket model (3) and/or in the virtual carrier plate (1,16,19) in this final position; - Generating a data record on the basis of the alignment of the virtual toothed ring model (3) relative to the virtual carrier plate (1,16,19) and the definition of the distribution of the receiving holes (6,11); - Using this data set to produce a physical toothed ring model (3) by means of an additive manufacturing process; characterized by the further steps: - after aligning the virtual gear ring model (3) relative to the virtual carrier plate (16) in the desired final position, defining a virtual fastening structure consisting of rod-shaped fastening elements (13) protruding outwards on the virtual gear ring model ( 3) which are aligned and designed in such a way that they can interact with corresponding fastening elements (14) which are provided on a holder (15) of a pin drilling device for the physical support plate (16); and - producing physical fastening elements (13) together with the physical toothed ring model (3) on the basis of the virtual fastening elements (13) by the additive manufacturing process. procedure after claim 1 , in which the receiving holes (6,11) in the physical sprocket model (3) are produced with the additive manufacturing process. procedure after claim 2 , in which the guide elements (12) for the guide pins (8,21) are also produced in the additive manufacturing process. procedure after claim 1 , further comprising the step of: - defining virtual stiffening elements (17) on the virtual toothed ring model (3); and - producing physical stiffening elements (17) together with the physical toothed ring model (3) on the basis of the virtual stiffening elements (17) by the additive manufacturing method. procedure after claim 1 or 4 , in which the receiving holes (6,11) to be provided in the physical sprocket model (3) and/or the physical support plate (1,16,19) are drilled on the basis of the positions resulting from the specified distribution of the virtual receiving holes (6,11). will. procedure after claim 5 , comprising the steps of: - Forming of through holes (20) in the support plate (19); - Insertion of guide pins (21) in the through holes (20); - aligning the physical sprocket model (3) with respect to the physical carrier plate (19) when placing the sprocket model (3) on the carrier plate (19) when the guide pins (21) of the carrier plate (19) are slidably received in receiving holes (6) in the sprocket model (3); and - after the toothed ring model (3) has been aligned with respect to the carrier plate (19), the guide pins (21) are fixed in the through-holes (20). A computer-readable medium containing program instructions which, when executed on a computer, cause the computer to perform the method of any preceding claim. Device for producing receiving holes (6, 11) in a physical sprocket model (3) and/or in a physical support plate (16), the sprocket model (3) being produced by means of an additive manufacturing process together with a fastening structure consisting of outwardly protruding, rod-shaped Fastening elements (13) can be produced on the dental arch model (3), having a holder (15) for a carrier plate (16) on which the dental arch model (3) can be arranged for dental modelling, characterized in that the holder (15) has fastening elements (14) which cooperate with the fastening elements (13) of the ring gear model (3). device after claim 8 , in which the fastening elements (14) of the holder (15) and the fastening elements (13) of the ring gear model (3) form a locking connection.

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