Manufacturing device for manufacturing a blank for a dental prosthesis, manufacturing method for a blank for a dental prosthesis, and blank

Abstract

To provide a manufacturing apparatus for manufacturing a blank of a dental prosthesis, especially of polimerization.SOLUTION: A mold for housing a blank material is provided with a base part especially of a pan shape or a pot shape, and a punch or a (occasionally hood-shaped) lid member. There are provided: an insertion body having a structure on a lower surface; a heater 43 for the mold; and a control unit 45 for a manufacturing apparatus. A height measuring device 30 measuring a height with respect to a base part of a reference surface 32 combined with the punch or the lid member is connected to the control unit. The control unit calculates a height position of the structure on the basis of the measured height.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The invention relates to a manufacturing device for manufacturing blanks for dental prostheses according to the preamble of claim 1, a method for manufacturing blanks for dental prostheses according to the preamble of claim 15 as well as a dental prosthesis blank according to the preamble of claim 17. [Background technology]

[0002] Devices for the production of dental prostheses, such as dentures, have been known for a long time. Already from DE 652 821 B1 an injection mould is known which is filled with a polymerisable material.

[0003] From German utility model 202006006286 (U1) a multicolored blank is known, which is set up in a dental milling machine for milling, for example, dentures.

[0004] EP 3064170 A1 discloses an important improvement in the production of denture blanks, namely a special two-tone blank, which is disk-shaped and comprises, on the one hand, preformed tooth material and, on the other hand, preformed denture base material. Both complete and partial dentures can be produced completely from such blanks.

[0005] For the production of such blanks, a manufacturing device using an insert has been proposed. According to this proposal, the tooth material is first injection molded and polymerized with the aid of the insert. The insert is then removed and the base material is injection molded between the exposed surface of the tooth material and the lid. The surface of the tooth material is used as a form for the base material, so to speak, forming the interface between the two materials. The final polymerization then achieves a highly effective bond between the base material and the tooth material.

[0006] However, when the internal inspection was performed, the height position of the interface between the tooth material and the base material was extremely variable. It is assumed that the polymerization shrinkage varies greatly from one piece to another, and the filling amount during injection molding is also an issue.

[0007] It has also been proposed to machine oversized dies with calculated material surpluses to get closer to the required tolerances. This is feasible and achieves some improvement, but is not suitable for mass production techniques. In addition, material inhomogeneity and metrology and production errors are also problems. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] German Patent No. 652821 (B1) [Patent Document 2] German Utility Model No. 202006006286 (U1) [Patent Document 3] European Patent Application Publication No. 3064170 (A1) Summary of the Invention [Problem to be solved by the invention]

[0009] It is therefore an object of the present invention to provide a manufacturing device for manufacturing blanks for dental prostheses according to the preamble of claim 1, a method for manufacturing blanks for dental prostheses according to the preamble of claim 15 as well as a dental prosthesis blank according to the preamble of claim 17, which are more suitable for mass production techniques and nevertheless allow improved precision. [Means for solving the problem]

[0010] This problem is solved according to the invention by claim 1, claim 15 or claim 17. Advantageous additional features are defined in the dependent claims.

[0011] According to the invention, a manufacturing device for producing blanks for dental prostheses, in particular to be polymerized, comprises a mould for receiving the blank material, in particular with a pan- or bowl-shaped base and a punch or possibly a hood-shaped lid. A transport track is preferably provided as a support on which the mould rests or stands. The transport track can be a transport belt or a hard, preferably smooth, surface on which the mould can slide.

[0012] The insert preferably has a structure on its underside that allows it to be inserted into the mold. Optionally, the insert can be integral with the punch or the lid. The insert preferably occupies an upper part of the base, thus leaving a space below which can be filled with material, in particular an injection-molding tooth material.

[0013] A heating device of the type is provided, which is in particular thermally conductively connected to the lid member or arranged within the lid member, and a control device for the heating device is provided.

[0014] Alternatively, heating can be applied from below and / or from both sides. Polymerization can also be initiated or controlled by other methods (light), in which case a transparent mould is preferred.

[0015] The mould is subjected to high pressure, which may be, for example, 80 bar. Polymerisation may be followed by rapid cooling. It is also possible to use self-polymerising resins.

[0016] According to the present invention, furthermore, a height measuring device for measuring the height of a reference surface connected to the punch or the cover member relative to the base or support is connected to the control device.

[0017] The controller calculates the height position of the structure within the blank based on the measured height.

[0018] For the calculation, it is assumed that all rigid, e.g. metallic, parts of the manufacturing device have known and unchanging dimensions, including the base. If the base is pot- or bowl-shaped, it comprises a base bottom floor and a base wall. The base rests on a fixed support. The lid or punch has a known height, as does the insert. If both are one piece, they have a known total height. The reference plane is set on the lid and is preferably formed by the top surface of the lid.

[0019] According to the invention, it is preferred that a first material, preferably a tooth material, is first prepared and injected into a mould using a structured first cover member (as the first member), after which the first cover member is removed and a flat second cover member is placed, and a second material, for example a base material, is injection moulded (as the second member).

[0020] However, the present invention is not limited to the above procedure.

[0021] Alternatively, the mould can be used only to produce a first part and then a height measurement of that part is taken. The second part is then placed onto the first part in a separate mould.

[0022] Alternatively, the second member can be glued after the height of the first member is measured.

[0023] Instead of injection molding, the first component can also be manufactured by a subtractive process, for example by milling. In that case, the height measurement can be carried out after the first component has been inserted into the mold. To this end, the first component is provided with a flat reference surface, the height of which is measured by a height measuring device. The measurement result is transmitted to a control device.

[0024] Furthermore, the second part can be manufactured in any manner (independently of the first part). It can be attached after measuring the height of the first part. It can also be manufactured by additive methods, for example by 3D printing, and then glued or polymerized.

[0025] The height gauge device simply measures the height of the reference plane above the abutment on which the base of the mold rests, so that the overall height of the mold is known. The height itself is not important, but it allows the calculation of the height position of the structures in the (later) blank, and is calculated by the following formula:

[0026]

number

[0027] The height position of the structure corresponds to the position of the material transition in the disk-shaped blank. Above the material transition, base material of color A is provided, below the material transition, tooth material of color B is provided. The precision of the material transition from color A to color B provides an important basis for the esthetic processing of dentures, hybrid dentures or partial dentures, especially denture bases, from the multi-colored disk-shaped blank.

[0028] Preferably, the control device outputs information as to whether the measured height is within an acceptable error range. In the present invention, the acceptable error range in dental technology is ±500 μm.

[0029] The solution according to the invention allows the above-mentioned tolerances to be significantly exceeded if necessary, even in the presence of raw material variations, input and process errors that lead to variations in the material transitions in the above-mentioned ranges.During the manufacturing process, and in particular by measuring the exact material height in the mold after polymerization of the first material layer, the exact or approximately exact position of the material transitions can be transferred to every individual blank during subsequent manufacturing by CAD / CAM technology and can be accurately applied during milling.

[0030] Within the entire system of blank disc, milling holder and milling machine, the extremely large error factors that affect the visual quality can be significantly reduced.

[0031] The measurements for each blank can therefore be transferred manually to the CAM or stored on an RFID transponder and recognised directly by the CAM software when reading the blank. The software then transfers the compensation values ​​to the CNC milling program. It is therefore guaranteed that the material transitions are fitted in the correct position and that the appearance of the denture base is created at a constant height.

[0032] In particular, multi-coloured milling blanks for producing monolithic denture bases have a material transition of tooth material to a horizontal base material (also called gingival material) which runs parallel to the denture base, which in the solutions proposed before the present invention inevitably led to an insufficient aesthetic formation, especially in the gingival margin or in the tongue dorsum area of ​​the denture base. Intensive post-processing, such as the application of characterising materials, was necessary and burdensome.

[0033] The above problems are overcome by the present invention, which allows for highly pleasing aesthetic formation, especially in the gingival margin or tongue dorsum area of ​​the denture base.

[0034] Additionally, the predefined, eg wavy, gingival internal geometry of the present invention (approximating the contour of the natural gingival margin) reduces post-processing and improves results.

[0035] The method for manufacturing, for example of a multi-color milling blank according to the invention, allows for an accurate determination of the material height, in particular the transition line formed by the interface from color A to color B. This technical advantage allows for the transfer of measurement data to the milling software or other CAM software. The possibility of establishing an approximately exact positioning of such a transition is an important advancement.

[0036] Via the measurement system, information regarding the internal geometry or the position / alignment of color transitions between materials is determined and can be applied to subsequent CAD / CAM processes.

[0037] In order to communicate and reproduce the internal geometry of the invisible disk, i.e. the exact position / alignment of the interfaces between materials, the height positions of the interfaces are calculated, for example according to the formulas above.

[0038] Based on this, a correction value is determined, for example as the (positive or negative) difference between the nominal height position of the interface and the calculated height position. The correction value is transmitted to the CAD / CAM system. This results in an optimal and reproducible improvement and guarantee of esthetics. Extensive post-treatment or corrections on the denture base are omitted.

[0039] In a preferred embodiment, the correction factors are printed on the blank, attached, or readable / recallable by an RFID transponder. The correction factors can also be encrypted and stored in a central cloud.

[0040] According to a preferred embodiment, the mould according to the invention is placed on a support, which is fixed to the underside of the mould, and the height measuring device is capable of measuring the distance between the upper surface of the mould and the base, i.e. the underside of the base.

[0041] The top of the mold is formed by a punch or a cover member, which closes the top of the mold and forms a molding space for injection molding. The cover member has a top surface. The top surface functions as a reference surface. The height gauge device measures the distance between the top surface of the cover member and the base, i.e., between the reference surface and the support.

[0042] In a preferred embodiment, the height measuring device comprises at least one contact probe, which measures the height of the reference surface. According to another improved embodiment, the height measuring device comprises at least three contact probes, which also makes it possible to measure the height of the reference surface in three-dimensional space.

[0043] According to another preferred embodiment, the height measuring device comprises, instead of a contact probe, an optical sensor, a laser distance meter, an ultrasonic sensor, an infrared distance meter or an infrared optical sensor, which may also comprise a reference optical element which acts together with at least one reference point to detect the position of said reference point and thereby detects the deflection of the reference surface, in particular the cover part, relative to the base or support and transmits it to the control device.

[0044] Alternatively, the height measurement device may comprise a capacitive or DMS sensor, which already responds to and measures slight relative movement between the lid member and the base.

[0045] In such a sensor, it is preferred that one element of the sensor is mounted on the lid, in particular at the skirt of the lid, and another element is mounted adjacent the base.

[0046] It is preferred that the height measuring device has an accuracy of less than 2 mm, in particular less than 0.3 mm, more preferably about 0.1 mm. A preferred height measuring device operates with an accuracy of 0.01 mm. The tolerance set is 0.5 mm. If the measured layer is, for example, 0.6 mm higher than the defined tolerance, i.e. has a height higher than, for example, 0.6 mm, the product is indicated as defective.

[0047] The actual height position is calculated based on the measured data, for example according to the above-mentioned formula, and the height position of the structure is determined. The structure can be formed in various ways, preferably in a wave shape. The reference points of the structure are determined, and the control device outputs data on the height position of the structure based on the three reference points.

[0048] The height positions of the structures of the corresponding blanks, present in data form, are assigned to the blanks in a suitable manner according to the invention, so that the height position data are always available. For this purpose, for example, an output device can be provided which is connected to the control device and which assigns the data to the corresponding blanks and stores them in the database.

[0049] Alternatively, the output device can be a printer for creating a label, which is applied in printed form onto the blank. Alternatively, the output device can be formed as an RFID chip programming device. After programming, the created and programmed RFID chip is attached onto the blank. Thus, the height position data is assigned electronically (e.g. via a database) or placed near the blank via an information carrier.

[0050] The information medium may be any medium on which data may be assigned to the blank, for example, the data may be laser written, engraved, embossed or printed on the blank, and may be in text form or may be encoded.

[0051] According to a preferred embodiment, a heating device for the mold is provided, which is thermally conductively connected to the lid. According to a preferred embodiment, two lids / punches are provided, one with an insert / structure and one without an insert / structure. First, a first lid having a structure or an insert with a structure on its underside is mounted on the base. A first material, preferably a tooth material, is injected. Polymerization, or at least partial polymerization, of the material is performed. The first lid is removed. The material has a female structure on its upper side that exactly matches the impression of the structure.

[0052] The second cover part has a flat underside and a lower height than the first cover part. Between its underside and the female structure there is a free space. A second material, preferably a base material, is injected into this free space, with the female structure forming part of the mold space. Polymerization is carried out again, in such a way that both materials are completely polymerized. After cooling, demolding is carried out and the milling blank is finished as a semi-finished product.

[0053] It is also possible to transfer the first part of the blank (made of a first material) to another mould where the second part is attached, thus completing the blank disc, thereby making it possible to realise a time- and possibly energy-saving process.

[0054] According to a preferred embodiment, an output device is connected to the control device, which outputs the height position of the structure relative to the support, in particular relative to the transport path on which the mould can be placed or on which the mould stands.

[0055] Alternatively, the combined height of the base and punch or lid member is output.

[0056] According to another embodiment, the output is sent to a database for assigning data to blanks for the respective molded dental prostheses, to a label printer capable of printing labels to be attached to the blanks, or to an RFID chip programming device.

[0057] Alternatively, the control device stores the data in a memory, in particular in a database memory, which memory is accessible, in particular online accessible, by the milling machine for milling the dental prosthesis.

[0058] The controller performs calculations to determine the height position of the structure in the blank. To this end, a known distance between the lower surface of the insert and the upper surface of the lid member is stored in the controller. From that distance, the controller subtracts the height measured by the height measuring device and the distance between the lower inner surface of the mold and the lower surface of the mold. The controller thereby determines the height position of the structure and / or the combined height of the base and punch or lid member.

[0059] According to another preferred embodiment, the manufacturing device and the blank material according to the invention form a system for manufacturing a semi-finished product as a milling blank, which preferably has a disk shape. A dental prosthesis or partial denture can be manufactured from the milling blank in a dental milling machine. It is preferred that a tooth material and a base material are used as the blank material, and the structure corresponds to the interface between the tooth material and the base material of the semi-finished product to be manufactured, and preferably forms a catenary line in the semi-finished product along the gingival margin.

[0060] Many variations of the method according to the invention (and therefore the necessary apparatus for its implementation) are possible. The tooth and base materials can be polymerizable resins such as PMMA, ceramics such as zirconium dioxide or lithium metasilicate as blanks, or composites or any other suitable dental materials.

[0061] It is also possible to combine different materials for the abovementioned tooth and base materials, in which case the manufacturing process must of course be adapted to the respective material used, thus e.g. polymerization (at least partial polymerization) for plastics, sintering or isostatic pressing (hot or cold isostatic pressing, preferably cold isostatic pressing) for ceramics.

[0062] Basically, the following possibilities exist for the production of internally structured blanks for forming dentures or partial dentures:

[0063] The tooth material may be the first material or the base material may be the first material, and in either case the other is the second material.

[0064] A first material is manufactured using a subtractive process, and a second material is applied onto it using an adhesive process.

[0065] A first material is produced by a subtractive process, a second material is also produced by a subtractive process, and then both materials are bonded together.

[0066] A first material is produced by means of a press, in particular an isostatic press, on which a second material is applied in a lamination process.

[0067] A first material is produced by a subtractive process, onto which a second material is additively pressed by means of a press, in particular an isostatic press.

[0068] The first material is produced by pressing, in particular by cold isostatic pressing, onto which the second material is additively pressed by pressing, in particular by cold isostatic pressing. Surprisingly, this embodiment makes it possible to dispense with the use of adhesive.

[0069] In a known manner, shrinkage ("sintering shrinkage") is taken into account during pressing, in particular isostatic pressing, so that the target position of the structure, for example the wavy structure, can be preset in such a way that the catenary of the boundary line subsequently corresponds to the gingival margin.

[0070] A first material is introduced into a mold equipped with the height measuring device according to the invention, the lid part of which has a negative image of the structure, the height position of which is measured (possibly in three dimensions) and a sample of the green body is assigned thereto and stored, for example in a database, corresponding to the individual green body.

[0071] According to a preferred embodiment, the first material is pre-pressed uniaxially and the second material is pre-pressed uniaxially or by isostatic pressing. Afterwards, both pre-workpieces (= "green bodies") are processed by subtractive methods, in particular by milling, in order to subsequently form a structure on the mutually facing side, the second material having a negative image of the structure, also called the complementary structure. The green bodies are placed one above the other and cold isostatically pressed together, in the process bringing them to their final pressing density and bonding them to each other.

[0072] The bonded green bodies are then separated and presintered.

[0073] The joined green body is then placed in a mold with a height measuring device according to the invention, the lid of which is flat, and the height position of the lid is measured (possibly in three dimensions) and a sample of the joined green body is assigned to it and stored, for example in a database, in correspondence with the green body.

[0074] As a result, the bonded green body is ready for sale as a semi-finished product (also called a blank) together with data on the height positions of the internal structures in a database.

[0075] The user can mill the required dental prosthesis from the semi-finished product and sinter it to a high density. The user preferably takes into account the height position of the structures already during CAD or at the latest during CAM, i.e. during milling.

[0076] Further details, features and advantages of the invention will become apparent from the following detailed description of an embodiment which refers to the accompanying drawings. [Brief description of the drawings]

[0077] [Figure 1] 1 is a three-dimensional explanatory diagram showing a schematic embodiment of the present invention together with a mold including a lid member and a contact probe according to the present invention; [Diagram 2] 1 is a three-dimensional explanatory diagram showing a schematic embodiment of the present invention together with a mold including a lid member and a contact probe according to the present invention; [Diagram 3] FIG. 11 is a cross-sectional view illustrating another embodiment of the present invention. [Figure 4] FIG. 11 is a cross-sectional view illustrating a schematic configuration of yet another embodiment of the present invention. [Diagram 5] FIG. 4 is a cross-sectional view showing a state after a prefabricated first member has been inserted into a mold. [Figure 6] FIG. 1 is a schematic diagram of a blank produced according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0078] FIG. 1 shows a schematic diagram of a manufacturing apparatus 10 for producing blanks for dental prostheses, such as dentures.

[0079] The manufacturing device 10 is designed to produce blanks as semi-finished products from which dental prostheses can be produced in a subsequent manufacturing step. The blanks consist of two materials, one a tooth material intended for the teeth and the other a base material for the denture base. Between the materials a structured interface, i.e. a structure, is formed.

[0080] The manufacturing device 10 comprises a mould 14 mounted on a support 12. The mould 14 is formed as a mould and is therefore suitable for receiving material for injection moulding.

[0081] The mould 14 consists of a base 16 and a lid member 18. The base 16 is designed to be pot-shaped, thus essentially U-shaped, and closed at the top by a lid member 18. The bottom floor 17 of the mould has a fixed, set height. Within the mould 14 a moulding space 20 is formed, which can be filled with injection moulding material.

[0082] In the embodiment of Fig. 1, the lid part forms a skirt 19 which covers the base part 16, which improves the mutual guidance of the base part and the lid part. Furthermore, a short sealing projection 21 extends into the base part, where the moulding space 20 is sealed.

[0083] As an alternative to such a basic configuration of the mold 14, it is also possible to omit the skirt 19 (FIG. 3) or to divide the mold 14 symmetrically, for example into two mold halves, as is often done in forming molds.

[0084] In the state shown in Figure 1, the moulding space 20 is filled with tooth material 22. The tooth material 22 is a white or white-ish dental material from which the denture teeth will be milled in a subsequent manufacturing step.

[0085] The face of the tooth material 22 facing the lid part 18 has a complementary structure 24. The complementary structure 24 can be flat, but in the embodiment shown is three-dimensional, i.e. has projections and recesses. The complementary structure simultaneously forms an interface 26 for the base material, which is not yet attached. Thus, a blank is formed from the tooth material 22 on the one hand and the base material on the other hand.

[0086] The production of blanks in the production device 10 proceeds as follows:

[0087] An insert 40, such as that shown in Figure 3, is inserted into the molding cavity 20. The insert has a structure 44 facing downwardly that is complementary to the complementary structure 24 shown in Figure 1. An injection molding cavity is formed between the complementary structure 24 and the base 16.

[0088] The injection mold cavity is then filled with tooth material 22. A heating device is built into the insert or cover member 18. The heating device is turned on and the tooth material 22 is partially polymerized, i.e., prepolymerized.

[0089] 3, and in this state, measurements are performed as described below by the height measuring device 30. For this purpose, the upper surface of the cover member 18 is formed as a reference surface 32, and its height is measured relative to the base 12.

[0090] The insert 40 is then removed. The lid 18 is then refitted. Between the lid 18 and the complementary structure 24, an injection moulding space 34 is formed, as shown in FIG. 1. The injection moulding space 34 is then filled with base material. The mould 14, now filled with base material (and tooth material), is then heated by a separate heating device or by the same heating device, and the materials polymerise. The tooth material 22, which was only pre-polymerised, is now fully polymerised, whereby a very good bond between the materials is achieved at the interface 26.

[0091] Although the manufacture of the blank 46 is described here in connection with an injection molding method, it is understood that any other manufacturing method is possible, for example a casting process can be used, in which case the closure element 18 is applied after a corresponding pouring step.

[0092] The interface 26 forming the complementary structure 24 can have any suitable shape, with a shape that accommodates the human gingival margin being preferred, i.e., the shape of a catenary extending from distal to mesial and back toward another distal side.

[0093] In particular, determining the height position of the boundary surface is important because that height position must coincide with the height position of the human gingival margin.

[0094] However, the determination of the height position according to the invention is not only applicable to the interface between the tooth material and the base material, but also to so-called multi-material layers. In that case, a multi-layer tooth material or base material is understood, where the tooth material is usually formed from a darker layer on the gingival side and a lighter layer on the incisal side. Such layer interfaces are also often not flat, but are for example curved and are produced in multiple molds as described. The interface and height positions in such multi-materials can be determined in a similar manner to the above-mentioned method.

[0095] In the embodiment of Fig. 1, the height measuring device 30 comprises a contact probe 36. In contrast to this, in the embodiment of Fig. 2, three contact probes 36 are distributed over the reference surface 32. This configuration allows not only the height position but also the position in space to be detected. This is valid for the reference surface 32, but also for the interface surface 26, taking into account the physical connection via the insert 40 and the lid 18.

[0096] In Fig. 3 another embodiment of the invention is shown, in which the measurement is carried out when the insert 40 contacts through its structure 44 the complementary structure 24 of the tooth material 22 formed by said structure 44. A heating device 43 is arranged in the lid part 18 or in the insert 40, which serves for the prepolymerization of the tooth material 22.

[0097] According to the invention, the height position H of the interface 26 in the rear blank 46 s According to the embodiment of Fig. 1 to 3, a disk-shaped, flat-cylindrical blank is produced. The reference for the height position is here the lower surface of the blank, which in this case corresponds to the lower surface of the tooth material 22. The height position H s is calculated using the following formula:

[0098]

number

[0099] According to the invention, the fact that the metal mold 14 in this case has known dimensions is utilized, which include a height H b , H d and H e Here, the total height H g is measured by the distance of the reference plane 32 from the abutment 12, the remaining variable H S can be easily determined.

[0100] The insert 40 can be integral with the lid member 18 or can be separate. If it is an integral configuration, the combination of lid member 18 and insert 40 can be replaced with a flat lid member 18 for the second step in the manufacture of the blank. If it is a two-piece configuration, the mold 14 is opened, the insert 40 is removed, and the lid member 18 is reinstalled to form the molding cavity 34 for the second step.

[0101] The insert 40 has a structure 44 on its underside. In the case of a one-piece construction, the structure 44 is provided on the underside of the lid member 18. The second lid member is preferably flat and may optionally have a protrusion 21 as shown in FIG.

[0102] The base 12 may be a rigid and flat base, e.g., made of metal, upon which the form 14 may slide, or the base may be a track or carriage upon which the form 14 may rest or stand, upon which or by which the form 14 may move.

[0103] 3 shows a control device 45 connected to the height gauge device 30. The control device 45 carries out the calculations according to the above-mentioned formulas and stores the associated data corresponding to the completed blanks.

[0104] 4 shows another embodiment of the invention. In this embodiment, the blank 46 is not a pure flat cylinder, but has a circumferential flange 48 on which the blank 46 is fixed to a holder of a milling machine (not shown). One side of the flange 48 therefore serves as a height reference. In the illustrated embodiment, the lower radial surface of the flange 48, which connects to the tooth material 22, is used for the height reference.

[0105] That is, the datum does not correlate to the underside of the disk of blank 46, but rather to the height H r Correlated with.

[0106] The value is also fixed because it exists within the metal member of the base 16. In this case, the height position H S The determination is performed according to the following formula:

[0107]

number

[0108] In this embodiment, the lid member 18 is punch-shaped to serve to shape the upper region of the flange 48. The lid member may therefore have a hood-shaped appearance. Referring to Figure 5, another embodiment of the manufacturing device 10 according to the present invention is partially shown.

[0109] Only the base 16 is shown, the lid part 18 being omitted. Into the base 16 is inserted a first part 50 of the milling blank to be produced, which is already provided with the complementary structure 24 on its upper surface.

[0110] The member 50 fits precisely into the base 16. The member 50 can be prefabricated in any suitable manner. For example, the member 50 can be manufactured by a fabrication method such as three-dimensional printing, or it can be manufactured in a dedicated injection mold or mold that corresponds to the mold 14. It is also possible to manufacture the member 50 in a subtractive manner, for example by milling.

[0111] The component 50 is provided with a material reference surface 54 on its upper surface, for example at an edge, the position of which is measured using the measuring probe 36 of the height measuring device 30. The same height measuring device 30 as in the other embodiments or a different height measuring device can be used.

[0112] The output signal of the height measuring device 30 is transmitted to the control device and evaluated as described above. If the height position of the material reference surface 54 is within a tolerance of, for example, 0.5 mm, the milling blank is finish-machined by placing the second cover member 18 having a flat lower surface on the base 16 and closing the mold 14, as shown in FIG.

[0113] The base material is injected to form the second part of the blank, and further polymerization is carried out, thereby forming a blank consisting of the first part 50 prefabricated with the tooth material and the injected base material, the interface having a height within a given tolerance range.

[0114] Height H of the first member 50S The calculation of H g -H b The measurement is performed in the same manner as the subtraction of the base 12 from the material reference surface 54. Here again the base 17 has a known height.

[0115] 6 shows a schematic representation of a blank 46. The blank 46 is manufactured according to the invention and includes a circumferential flange 48. The interface 56 between the tooth material 22 and the base material extends within the height of the flange 48.

[0116] The gingival margin is formed at that position on the completed denture later. The height position is set with an accuracy of about 0.5 mm.

[0117] To manufacture the denture, the blank 46 is clamped in a clamping device of a dental milling machine. It is necessary to determine the relative position of the blank with respect to the clamping device very accurately. For this purpose, the lower surface 60 of the flange 48 forms a reference surface, the height H of which relative to the lower surface 62 of the milling blank has an error margin of, for example, 0.02 mm.

[0118] Maintaining such small tolerances is readily possible by using a steel form for base 16, which also applies to the formation of flange 48. If surface 60 is used as a datum surface, it becomes unnecessary to use height gauge device 30 of the present invention to measure the height position of that datum surface.

[0119] On the other hand, if the opposite surface, ie the surface formed from the base material, is used, its height must be measured using the height measuring device 30 as described above.

Claims

1. 1. A manufacturing apparatus for manufacturing a dental prosthesis blank, comprising: a mold for accommodating blank material, the mold comprising a punch or cover member (18) having a base (16) and a lower surface, and further comprising a control device (45) for the manufacturing apparatus, wherein a height measuring device (30) for measuring the height of a reference surface attached to the punch or cover member (18) relative to the base (16) or an abutment on which the base (16) is placed is connected to the control device (45), and the control device (45) calculates the height position of the lower surface of the punch or cover member (18) based on the measured height.

2. 2. A manufacturing apparatus for manufacturing a dental prosthesis blank as claimed in claim 1, characterized in that a reference surface is formed on an upper surface of the punch or cover member (18), and a height measuring device (30) measures the distance between said upper surface and the base (16) or an abutment on which the base (16) is placed.

3. 3. A manufacturing apparatus for producing a dental prosthesis blank as claimed in claim 1 or 2, characterized in that the height measuring device (30) comprises at least one optical sensor or one or more contact probes by means of which the position in three-dimensional space of the punch or cover member (18) can be measured in addition to its height.

4. 4. A manufacturing device for manufacturing a blank for a dental prosthesis according to claim 1, characterized in that a structure (44) is formed on the underside of the cover part (18) or the insert, the height position of the structure (44) calculated by the control device (45) includes the calculation of at least one reference point of the structure (44), the control device (45) outputs data relating to the height position of the structure (44), and the control device (45) determines the height position of the structure (44) and / or determines the height of the blank.

5. 5. A manufacturing device for manufacturing dental prosthesis blanks as claimed in claim 4, characterized in that an output device is connected to the control device (45), which outputs a height position relative to a transport path on which an abutment or a mold can be placed or on which the mold stands, and outputs data to a database for assigning data to blanks for dental prostheses respectively formed, a label production printer capable of printing labels to be attached to the blanks, and an RFID chip programming device, and further the control device (45) stores the data in a memory of the database and makes the memory accessible online to a milling machine for milling the dental prosthesis.

6. 6. A manufacturing device for producing a blank for a dental prosthesis as claimed in claim 4 or 5, characterized in that a tooth material and a base material are used as blank materials, and the structure (44) corresponds to an interface between the tooth material and the base material in the blank to be produced.

7. 7. A manufacturing device for producing a blank for a dental prosthesis according to claim 4, characterized in that the structure (44) corresponds to an interface between different layers of tooth material and / or base material in the blank.

8. 8. A manufacturing device for producing a dental prosthesis blank according to claim 4, characterized in that the control device (45) subtracts for the calculation the known distance between the lower surface of the insert or lid part (18) and the upper surface of the lid part (18) and the distance between the lower inner surface of the mould and the lower surface of the mould from the height measured by the height measuring device (30), thereby determining the height position of the structure (44) in the blank.

9. A manufacturing apparatus for producing a blank for a dental prosthesis as described in any one of claims 1 to 8, characterized in that the circumferential edge of the blank is protruded by lowering the circumferential edge from the mold, the height position of the protrusion is calculated in accordance with the milling of the blank, the edge is adjacent to the structure (44), the base (16) of the mold has or forms a lower reference surface, and the height position of the base (16) of the mold is set as the calculated reference in accordance with the milling of the blank.

10. 10. A manufacturing device for producing blanks for dental prostheses as claimed in any one of claims 1 to 9, characterized in that the punch or the cover part (18) is provided with an insert having a structure (44) or the insert is at least indirectly connected to the punch or the cover part (18) and the measurement of the height position relates to the measurement of the underside of the insert.

11. 1. A manufacturing apparatus for manufacturing a blank for a dental prosthesis, comprising a mold for accommodating blank material, the mold comprising a punch or cover member (18) having a base (16) and a lower surface, and further comprising a control device (45) for the manufacturing apparatus, wherein a height measuring device (30) for measuring the height of a material reference surface relative to the base (16) or abutment on which the base (16) is placed is connected to the control device (45), and the control device (45) outputs information on whether the measured height is within an allowable error range based on the measured height.

12. A manufacturing method for manufacturing a dental prosthesis blank, using a mold having a punch or cover member (18) having a base (16) and a lower surface for containing a blank material, which is a tooth material and / or a base material, and further using a control device (45) for the manufacturing device, characterized in that a height measuring device (30) outputs to the control device (45) at least one measured value indicating the height of a reference surface or material reference surface connected to the punch or cover member (18) relative to the base (16), and the control device (45) calculates a height position of a structure (44) based on the measured height, or outputs information on whether the measured height is within an allowable error range.

13. A manufacturing method for producing a blank for a dental prosthesis as described in Claim 12, characterized in that a tooth material is pre-processed by three-dimensional printing and inserted into a mold, and a material reference surface is formed on the tooth material.

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