Manufacturing device for the manufacture of a blank for a dental restoration part, method for manufacturing a blank for a dental restoration part, as well as blank

Abstract

A manufacturing device is provided for the production of a blank, in particular one which is to be polymerized, of a dental restoration part. A mold for receiving blank material includes in particular a pot-shaped or cup-shaped base and a punch or—possibly hood-shaped—cover. An insert body with a structure on its underside and a heating device for the mold and a control device for the manufacturing device are provided. A height measuring device is connected to the control device, which measures the height of a reference surface connected to the punch or cover, relative to the base. The control device calculates the height position of the structure based on this measured height.

Claims

1. A manufacturing device for manufacturing a blank for a dental restoration part, comprising a mold for receiving blank material, said mold having a base and a punch or cover with an underside, and a control device for the manufacturing device, wherein a height measuring device is connected to the control device, which measures the height of a reference surface connected to the punch or cover, relative to the base or a support on which the base stands, and wherein the control device calculates the height position of the underside of the punch or cover based on the measured height.

2. The manufacturing device according to claim 1, wherein the reference surface is formed on the top of the punch or cover and the height measuring device measures the distance between an upper side of the punch or cover and the base or the support on which the base is placed.

3. The manufacturing device according to claim 1, wherein the height measuring device comprises at least one optical sensor or at least one touch probe, with which, in addition to the height, the position of the punch or cover can also be measured in three-dimensional space.

4. The manufacturing device according to claim 1, wherein a structure is formed on the underside of the cover or an insert body and the height position of the structure calculated by the control device comprises the calculation of at least one reference point of the structure, and wherein the control device outputs data on the height position of the structure.

5. The manufacturing device according to claim 4, wherein an output device is connected to the control device and outputs the height position in relation to the base, to a database for an assignment of data to a respective molded blank for the dental restoration part, or to a printer for generating labels which can be used to print labels for attachment to the blank, or to an RFID chip programming device, or wherein the control device stores the data in a memory in a database, which memory can be accessed by a milling machine for milling the dental restoration part.

6. The manufacturing device according to claim 4, wherein the structure extends three-dimensionally in space and spans a structural plane which has an inclination to the base of up to 30% and less than 15%, and whose height or spatial position relative to a support comprising a conveyor path, on which the mold can be placed or stands, is calculated by the control device using measurement results of the height measuring device.

7. The manufacturing device according to claim 4, wherein tooth material and base material are used as blank materials and the structure corresponds to a boundary surface between tooth material and base material in a semi-finished product to be manufactured, and forms a chain line along a gingival margin in the semi-finished product.

8. The manufacturing device according to claim 4, wherein the structure corresponds to the boundary surface between differently colored layers of tooth material and/or of base material in the blank.

9. The manufacturing device according to claim 4, wherein, for the calculation the control device subtracts a known distance between the bottom of the insert body or of a cover and a top of the cover from the height measured by the height measuring device and the distance between the lower inside of the mold and the bottom of the mold in order to determine the height position of the structure in the blank.

10. The manufacturing device according to claim 1, wherein the control device takes into account a material-dependent or material-conditional shrinkage factor for the shrinkage between partial polymerization and full polymerization in the output.

11. The manufacturing device according to claim 1, wherein the mold omits a circumferential edge which results in a projecting circumferential edge on the blank, the height position of which is taken into account as a calculated reference when milling the blank, the said edge being adjacent to the structure, in terms of height, wherein the base of the mold has or forms a lower reference surface, the height position of which is taken into account as a calculated reference when milling the blank.

12. The manufacturing device according to claim 1, wherein the height position data output by the control device also comprises data characterizing the boundary surface between the tooth material and the base material.

13. The manufacturing device according to claim 1, wherein the punch or cover comprises an insert body with a structure, and wherein the measurement of the height position relates to the measurement of the underside of the insert body.

14. A manufacturing device for manufacturing a blank for a dental restoration, comprising a mold for receiving blank material, said mold having a base and a punch or cover with an underside, and a control device for the manufacturing device, wherein a height measuring device is connected to the control device, which measures the height of a material reference surface relative to the base or a support on which the base stands, and wherein the control device outputs information based on this measured height as to whether or not the measured height lies within a tolerance range.

15. A method for manufacturing a blank for a dental restoration part, comprising a mold for receiving blank material, wherein the blank material comprises tooth material and/or gingival base material, with said mold having a base and a punch or cover with an underside, and with a control device for the manufacturing device, wherein a height measuring device outputs at least one measured value to the control device which represents the height of a reference surface connected to the punch or cover or of a material reference surface, relative to the base, and wherein the control device calculates the height position of the structure on the basis of this measured height or outputs information as to whether or not the measured height is within a tolerance range.

16. The method according to claim 15, wherein several molds are used successively for the production of the blank for the dental restoration part, a first mold having a structure at a first height relative to the base which is different from the height position of the structure of a second mold, and wherein the control device calculates the height position of the structure of the first mold and allows further production in the second mold if the height position is within a predetermined tolerance range.

17. The method according to claim 15, wherein a first material comprising the tooth material, is prefabricated by 3D printing, and is introduced into the mold, and the material reference surface is formed on the first material.

18. A blank with an information carrier, the blank being intended for use in or manufactured by a manufacturing device according to claim 1, wherein the information carrier indicates the height position of the structure or a spatial position of the structure in the blank or the total height of the blank, said structure forming a boundary surface between dental materials for the manufacture of the blank separating tooth-colored material from gingival-colored material.

19. The manufacturing device according to claim 3, wherein the at least one touch probe comprises a plurality of touch probes.

20. The manufacturing device according to claim 4, wherein the at least one reference point of the structure comprises at least 3 reference points of the structure, and wherein the control device determines the height position of the structure, and/or the height of the blank and/or the parallelism of its surfaces.

21. The manufacturing device according to claim 5, wherein the mold is placed on a conveyor path and the control device outputs the height position based on the mold on the conveyor path. is an output device is connected to the control device and outputs the height position on the base, in particular a conveyor path on which the mold can be placed or is placed, in particular to a database for the assignment of the data to a respective molded blank for the dental restoration part, or to a printer for generating labels which can be used to print labels for attachment to the blank, or to an RFID chip programming device, or in that the control device stores the data in a memory, in particular a database, which memory can be accessed, in particular online accessed, by a milling machine for milling the dental restoration part.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0101] Further details, advantages and features will be apparent from the following description of several exemplary embodiments of the invention with reference to the drawings, in which:

[0102] FIG. 1 is a schematized embodiment of the invention showing a mold including a cover and a touch probe according to the invention, in perspective view;

[0103] FIG. 2 is a schematized embodiment of the invention showing a mold including a cover and the touch probes according to the invention, in perspective view;

[0104] FIG. 3 is a sectional view of a further embodiment of the invention, also in schematized form;

[0105] FIG. 4 is a sectional view of a further embodiment of the invention, also in schematized form;

[0106] FIG. 5 is a sectional view of a pre-made first part, after insertion into the mold; and

[0107] FIG. 6 is a schematic view of a blank produced according to the invention.

DETAILED DESCRIPTION

[0108] In FIG. 1, a manufacturing device 10 for manufacturing a blank of a dental restoration part such as a dental prosthesis is shown in schematic representation.

[0109] The manufacturing device 10 is intended to produce a blank as a semi-finished product from which a dental prosthesis can be milled in a subsequent manufacturing step. The blank is to be composed of two materials, namely dental material for the teeth on the one hand and base material for the prosthesis base on the other. Between these materials there is a boundary surface which is structured, i.e., forms a structure.

[0110] The manufacturing device 10 comprises a mold 14 which is placed on a support 12. The mold 14 is configured as an injection mold and is accordingly suitable for receiving injection moldable material.

[0111] The mold 14 consists of a base 16 and a cover 18, the base 16 being pot-shaped and accordingly substantially U-shaped and intended to be closed at the top by the cover 18. Its base or bottom side 17 has a fixed predetermined height. A mold cavity 34 is formed in the mold 14, which can be filled by injection molding material.

[0112] In the embodiment according to FIG. 1, the cover forms a skirt 19 that overlaps the base 16. This improves the reciprocal guidance of the base and the cover. Furthermore, a short sealing projection 21 extends into the base. The mold cavity 34 is sealed there.

[0113] Instead of this basic design of the mold 14, it is also possible to omit the skirt 19 (FIG. 3) or, for example, to provide a symmetrical division of the mold 14 into 2 mold halves, as is often realized with injection molds.

[0114] In the state shown in FIG. 1, the mold cavity 34 is filled with tooth material 22. The dental material 22 is a white or whitish dental material from which teeth are milled in the later manufacturing step of a dental prosthesis.

[0115] The surface of the dental material 22 facing the cover 18 has a complementary structure 24. The complementary structure 24 may be flat, but in the illustrated exemplary embodiment it is three-dimensionally shaped, i.e., uneven. At the same time, it forms a boundary surface 26 with a base material that has not yet been inserted. The blank thus consists of tooth material 22 on the one hand and base material on the other.

[0116] The production of the blank in the manufacturing device 10 proceeds in the following steps:

[0117] An insert body 40, as shown for example in FIG. 3, is inserted into the mold cavity 34. The insert body has a structure 44 towards the bottom which is complementary to the complementary structure 24 as shown in FIG. 1. An injection molding space is formed between this complementary structure 24 and the base 16.

[0118] This injection molding space is now filled with tooth material 22. A heater is incorporated in the insert body or in the cover 18. The heating is switched on and the tooth material 22 is partially polymerized, i.e., pre-polymerized.

[0119] This state is shown in FIG. 3, and in this state a height measuring device 30 takes the measurement described further below. For this purpose, the upper side of the cover 18 is formed as a reference surface 32, the height of which is measured relative to the support 12.

[0120] The insert body 40 is then removed. The cover 18 is put back on. An injection molding space 34 is formed between the cover 18 and the complementary structure 24. This state is shown in FIG. 1. Base material is now filled into the injection molding space 34. The mold 14, which is now filled with base material—and tooth material—is then heated with another heater or the same heater and the material is polymerized. Since the tooth material 22 was only pre-polymerized, it is now polymerized to completion, so that a particularly good bond between the materials results at the boundary surface 26.

[0121] Although the manufacture of the blank 46 is described herein with reference to an injection molding process, it will be understood that any other manufacturing process is possible. For example, a pure casting process may be used. In this case, the cover 18 is then applied only subsequently to the casting step in question.

[0122] The boundary surface 26 forming the complementary structure 24 may have any suitable shape. Preferred is a shape adapted to the human gingival margin, i.e. the shape of a chain line extending from distal to medial and back to the other distal side.

[0123] The determination of the height position is particularly important for this boundary surface, because it should correspond to the height position of the human gingival margin.

[0124] However, the method of determining the height position according to the invention is not only applicable to the boundary surface between the dental material and the base material, but also, for example, to the layers of the so-called multi-materials. This is understood to mean a dental material or also a base material that is multi-layered, whereby in the case of the dental material there are typically gingival darker layers and incisal lighter layers. Such layer boundary surfaces are also often not flat, but curved, for example, and are created in multi-cavity molds in a similar way as described here. Boundary surfaces and their height position in these multi-materials can be determined analogously to the method presented here.

[0125] In the embodiment according to FIG. 1, the height measuring device 30 has one touch probe 36. In contrast, in the embodiment according to FIG. 2 there are 3 touch probes 36 distributed over the reference surface 32. With this design, not only the height position but also the position in space can be determined. This applies to the reference surface 32, but also to the boundary surface 26 in view of the physical connection via the insert body 40 and the cover 18.

[0126] FIG. 3 shows a further embodiment of the invention. This is shown in the condition in which measurements are taken, in which the insert body 40 with its structure 44 is in contact with the complementary structure 24 of the tooth material 22 formed by the structure 44. A heating device 43 is arranged in the cover 18 or in the insert body 40 and serves to pre-polymerize the tooth material 22.

[0127] According to the invention, the height position H.sub.s of the boundary surface 26 in the later blank 46 is to be determined. In the embodiment according to FIGS. 1 to 3, a disc-shaped, flat cylindrical blank is produced. The reference for the height position is here the underside of the blank, which here corresponds to the underside of the tooth material 22. The height position H.sub.s results from the following formula:

H.sub.s=H.sub.g−H.sub.d−H.sub.e−H.sub.b

[0128] Where:

[0129] H.sub.s: height position of the structure in the—later—blank.

[0130] H.sub.g: measured total height of mold

[0131] H.sub.d: known height of cover

[0132] H.sub.e: known height of insert body

[0133] H.sub.b: known height of base bottom

[0134] According to the invention, the fact that the metallic mold 14 has known dimensions is utilized here. These include the heights H.sub.B, H.sub.D and H.sub.e. If the total height H.sub.g is now measured from the distance of the reference surface 32 from the support 12, it is then easy to determine the remaining variable H.sub.s from this.

[0135] The insert body 40 may be either integral with the cover 18 or separate therefrom. In the one-piece embodiment, the combination of the cover 18 and the insert body 40 is replaced by a flat cover 18 for the second step in the manufacture of the blank. In the two-piece embodiment, the mold 14 is opened and the insert body 40 is removed and the cover 18 is replaced for the second step to form the mold cavity 34.

[0136] The insert body 40 has a structure 44 on its underside. In the one-piece embodiment, the structure 44 is provided on the underside of the first cover 18. The second cover is preferably flat, possibly with a protrusion 21, as can be seen in FIG. 1.

[0137] The support 12 may be either a solid and/or flat support, for example metallic, on which the mold 14 can be moved. The support can also be a path of movement or a conveyor path on which the mold 14 can be placed or stands, and on which or with which the mold 14 can be moved.

[0138] FIG. 3 also shows a control device 45 which is connected to the height measuring device 30. The control device 45 performs the calculation according to the above formula and the related data associated with the manufactured blank are stored.

[0139] FIG. 4 shows a further embodiment according to the invention. In this embodiment, a blank 46 is not purely in the shape of a flat cylinder, but has a circumferential edge flange 48. At this edge flange 48, the blank 46 is clamped in the holder not shown here of a milling machine. Accordingly, one surface of the edge flange 48 serves as a height reference. In the illustrated exemplary embodiment, the lower radial surface of the edge flange 48, which lies in the tooth material 22, is used for this purpose.

[0140] The reference is therefore different and does not refer to the lower surface of the disc of the blank 46, but to the height position of the edge flange H.sub.f.

[0141] However, this value is likewise fixed, because it is present towards the metallic body of the base 16. The height position H.sub.s is then determined with the following formula:

H.sub.s=H.sub.g−H.sub.d−H.sub.e−H.sub.f

[0142] Here:

[0143] H.sub.s: height position of the structure in the—later—blank

[0144] H.sub.g: measured total height of mold

[0145] H.sub.d: known height of cover

[0146] H.sub.e: known height of insert body

[0147] H.sub.f: known height of radial surface of edge flange

[0148] In this embodiment, the cover 18 is similar to a punch in that it is responsible for shaping the upper region of the edge flange 48. In this respect, it can also be regarded as hood-shaped.

[0149] FIG. 5 shows a further embodiment of a manufacturing device 10 according to the invention in parts.

[0150] Only the base 16 is shown and the cover 18 is omitted. A first part 50 of a milling blank to be manufactured is inserted into the base 16. This part already has the complementary structure 24 on its upper side.

[0151] The part 50 fits snugly into the base 16. It may be prefabricated in any suitable manner. For example, it may have been manufactured by an additive process such as 3D printing. It can also be made in a special injection mold or one corresponding to the mold 14 presented here. It would also be possible to manufacture the part 50 subtractively, for example by milling.

[0152] The part 50 comprises a material reference surface 54 on its upper side, for example at the edge. Its position is measured by means of a sensor 36 of the height measuring device 30. The same height measuring device 30 as in the other embodiments may be used, or a different one.

[0153] The output signal of the height measuring device 30 is fed to the control device and evaluated as previously described. When the height position of the material reference surface 54 is within a tolerance range of, for example, 0.5 mm, the milling blank is completed by placing the second cover 18 with the flat underside on the base 16 as shown in FIG. 1, thereby closing the mold 14.

[0154] Base material is injected to form a second part of the blank and polymerization is carried out. This produces a blank from the prefabricated first part 50 of tooth material and the injected base material, the boundary surface of which is at a height which is within the predetermined tolerance.

[0155] The calculation of the height H.sub.s of the first part 50 is carried out analogously to the previously described, by the subtraction H.sub.g−H.sub.b. Here, too, the base 17 has a predetermined height. The actual measurement takes place between the support 12 and the material reference surface 54.

[0156] FIG. 6 schematically shows a blank 46. The blank 46 is manufactured according to the invention and has a circumferential edge flange 48. A boundary surface 56 between the tooth material 22 and the base material extends within the height of the edge flange 48.

[0157] The gingival margin is later formed at this point in the finished prosthesis. Its height position is determined to an accuracy of about 0.5 mm.

[0158] For the fabrication of the prosthesis, the blank 46 is clamped in a clamping device of a dental milling machine. Here it is necessary to determine the relative position of the blank to the clamping device much more precisely. For this purpose, the lower surface 60 of the edge flange 48 forms a reference surface, the height H of which relative to the lower surface 62 of the milling blank is precisely determined, for example with a tolerance of 0.02 mm.

[0159] It is readily possible to maintain such a small tolerance by using a steel mold for the base 16, as this is also used for the embodiments of the edge flange 48. When the surface 60 is used as a reference surface, it is not necessary to use the height measuring device 30 according to the invention for determining the height position thereof.

[0160] If, on the other hand, the opposite surface, i.e. the surface consisting of the base material, is to be used, its height must be determined by using the height measuring device 30 as described above.

[0161] In some embodiments, the innovations may be implemented in additive manufacturing devices having diverse general-purpose or special-purpose computing systems. For example, the computing environment can be any of a variety of computing devices (e.g., desktop computer, laptop computer, server computer, tablet computer, gaming system, mobile device, programmable automation controller, etc.) that can be incorporated into a computing system comprising one or more computing devices.

[0162] In some embodiments, the computing environment includes one or more processing units and memory. The processing unit(s) execute computer-executable instructions. A processing unit can be a central processing unit (CPU), a processor in an application-specific integrated circuit (ASIC), or any other type of processor. In a multi-processing system, multiple processing units execute computer-executable instructions to increase processing power. A tangible memory may be volatile memory (e.g., registers, cache, RAM), non-volatile memory (e.g., ROM, EEPROM, flash memory, etc.), or some combination of the two, accessible by the processing unit(s). The memory stores software implementing one or more innovations described herein, in the form of computer-executable instructions suitable for execution by the processing unit(s).

[0163] A computing system may have additional features. For example, in some embodiments, the computing environment includes storage, one or more input devices, one or more output devices, and one or more communication connections. An interconnection mechanism such as a bus, controller, or network, interconnects the components of the computing environment. Typically, operating system software provides an operating environment for other software executing in the computing environment, and coordinates activities of the components of the computing environment.

[0164] The tangible storage may be removable or non-removable, and includes magnetic or optical media such as magnetic disks, magnetic tapes or cassettes, CD-ROMs, DVDs, or any other medium that can be used to store information in a non-transitory way and can be accessed within the computing environment. The storage stores instructions for the software implementing one or more innovations described herein.

[0165] Where used herein, the term “non-transitory” is a limitation on the computer-readable storage medium itself—that is, it is tangible and not a signal—as opposed to a limitation on the persistence of data storage. A non-transitory computer-readable storage medium does not necessarily store information permanently. Random access memory (which may be volatile, non-volatile, dynamic, static, etc.), read-only memory, flash memory, memory caches, or any other tangible, computer-readable storage medium, whether synchronous or asynchronous, embodies it.

[0166] The input device(s) may be, for example: a touch input device, such as a keyboard, mouse, pen, or trackball; a voice input device; a scanning device; any of various sensors; another device that provides input to the computing environment; or combinations thereof. The output device may be a display, printer, speaker, CD-writer, or another device that provides output from the computing environment.

[0167] The scope of protection of the present invention is given by the claims and is not limited by the features explained in the description or shown in the figures.