Blank for the production of dental prosthetic components

Abstract

Blank for the production of dental prosthetic components by material processing using a CAD / CAM machine, with a blank body made of a dental restoration material and a holding attachment connected to the blank body for holding the blank body in the CAD / CAM machine, the holding element is made of plastic.

Description

[0001] The present invention relates to a blank for the production of dental components by material processing using a CAD / CAM machine.

[0002] In the production of dental prosthetic components using a CAD / CAM machine, a blank made of dental restoration material is typically equipped with a holding attachment, acting as a workpiece carrier in the form of a clamping aid. This attachment allows the blank to be held / clamped within the CAD / CAM machine. Such a blank is described, for example, in EP 0 160 797 or EP 2 547 283. The holding attachment has a shape that can be accommodated by a corresponding holder in the CAD / CAM machine and can be moved with precise positioning within the machine. For this purpose, the holding attachment must ensure high mechanical strength and component rigidity. Conventional blanks use a metal alloy for the holding attachment, which may contain lead. Aluminum alloys are particularly common in the market.

[0003] Such a retaining element made of a metal alloy is expensive and often also detrimental from an environmental point of view due to the addition of lead and because the production is often energy-intensive, as in the case of aluminum alloys.

[0004] Furthermore, it is necessary to clearly identify the blank and, in particular, to determine the batch affiliation for each blank. Blanks consist, for example, of a ceramic material which is sintered after processing by the CAD / CAM machine. During sintering, the dental restoration material of the blank contracts. In order to provide dental prostheses with high accuracy, it is necessary to consider the material behavior during the sintering process. However, since the material behavior of the dental restoration material during sintering can be batch-dependent, it is necessary to clearly identify the blank, and in particular the blank body. The blank body can have a marking for identification purposes.The marking is achieved, for example, by adjusting the mold of the blank body, thus enabling direct marking of the blank. However, this results in high costs for the mold, which must be adapted depending on the batch.

[0005] The object of the present invention is to create a blank that is easier and more cost-effective to manufacture.

[0006] The problem is solved by a blank according to claim 1 and a blank according to claim 12.

[0007] According to the present invention, a blank for the production of dental prostheses is provided by material processing using a CAD / CAM machine. The blank comprises a body made of a dental restorative material. The dental restorative material is a medical device such as plastics and ceramics for dental applications. However, the present invention is not limited to a specific dental restorative material. The dental prosthesis(es) are then produced from the dental restorative material using the CAD / CAM machine. For this purpose, the blank has a holding attachment connected to the body for holding the blank within the CAD / CAM machine. The holding attachment defines the position of the blank within the CAD / CAM machine and enables movement of the blank through the CAD / CAM machine for processing.The holding element has a shape corresponding to the holder of the CAD / CAM machine, thus ensuring precise positioning of the blank body within the CAD / CAM machine. According to the invention, the holding element is made of plastic. In contrast to the prior art, which uses a metal holding element and, in particular, a holding element made of an FePb alloy, the present invention provides for the use of a plastic for the holding element. It has been shown that plastic provides sufficient strength and the necessary component stiffness. A holding element made of plastic is also more cost-effective to manufacture and avoids the use of environmentally harmful lead.

[0008] Preferably, the holding attachment has a circular cylindrical contour, with the axis defined by the cylinder axis passing through the center of the workpiece body. This allows the workpiece body to be rotated around the cylinder axis in the CAD / CAM machine. The holding attachment can be rotationally symmetrical. Alternatively, the holding attachment can be non-rotationally symmetrical, thus ensuring a unique orientation in the CAD / CAM machine.

[0009] Preferably, the holding element has a circumferential annular groove through which the holding element can be locked in the CAD / CAM machine by suitable means of the CAD / CAM machine. This ensures that the blank is securely held in the CAD / CAM machine.

[0010] Preferably, the holding element has an end face, wherein the blank body is connected to the end face of the holding element. In particular, the blank body is bonded to the holding element and especially to the end face.

[0011] Preferably, the end face has a surface roughness suitable for bonding. The end face can be textured and / or have a surface roughness in accordance with VDI Guideline 3400. The increased roughness of the end face ensures a secure bond between the retaining element and the blank body. In particular, the end face has a roughness greater than that of the rest of the retaining element. Specifically, the surface has a VDI 3400 value of 12 or higher, and preferably 30 or higher. This corresponds to a surface roughness (Ra) of 0.4 µm or more, and particularly 3.15 µm or more. The surface roughness can be generated by the mold used in an injection molding process. This eliminates the need for complex post-processing, such as that required for metal retaining elements.

[0012] Preferably, the holding attachment comprises a holding element and a holding pin. The blank body is connected to the holding element, and the holding element, in particular, forms the end face. The holding pin is located within the CAD / CAM machine's mounting area, and the holding element extends beyond the mounting area of ​​the CAD / CAM machine. In particular, the holding element and holding pin are formed as a single piece.

[0013] Preferably, the holding element has a larger diameter than the holding pin of the holding attachment. A radial outer surface of the holding element can be used as a radial reference surface for the tools of the CAD / CAM machine.

[0014] Preferably, the blank has an identification chip for identifying the blank body. The identification chip can be connected to the blank body or the holding attachment. In particular, identification information is stored on the identification chip for identifying the blank and / or the material it carries for the production of dental restorations. Specifically, the identification chip has a communication interface for wirelessly reading the identification information from the chip. Wireless reading of the identification chip can be achieved via Bluetooth, such as BLE, NFC, WiFi, UWB, or another wireless transmission standard. This eliminates the need to directly integrate information into the blank body, which would require a modification of the press mold.Rather, the identification chip with the necessary identification information can be subsequently attached to the blank body or the holding attachment.

[0015] In particular, the identification chip is an RFID chip.

[0016] Preferably, the identification chip is located internally and more preferably in a recess in the retaining element. In particular, the recess is located in the end face of the retaining element so that when the blank body is connected to the end face of the retaining element, the recess is covered or closed. Thus, the identification chip can be easily secured / fastened in the recess in one step, and the blank body can simultaneously be connected to the end face of the retaining element, for example by gluing.

[0017] In another version, instead of an identification chip, an identification feature such as a barcode or QR code is located on the outside of the blank, so that this code can be recognized and processed by a suitable reading device.

[0018] Preferably, the retaining element or the blank body has a marking. This can be, for example, a barcode, a QR code, or corresponding indentations according to EP 2 547 283. It is essential that, due to the use of plastic for the retaining element, such indentations can be easily incorporated directly into parts of the retaining element during the pressing process or subsequently applied in the form of a sticker, printing, laser engraving, or similar method. This eliminates either the need for subsequent processing of the blank body or modification of the pressing mold.

[0019] Preferably, the plastic of the retaining element is a polyamide such as PA6 or PAGF60.

[0020] Preferably, the plastic of the retaining element contains fillers to increase component stiffness. In particular, the plastic of the retaining element contains between 3% and 70% fillers, and especially between 5% and 50%. These fillers are primarily glass-based. Alternatively or additionally to glass-based fillers, fillers such as carbon fibers, talc, or calcium carbonate are used to improve the mechanical properties, thermal conductivity, or wear resistance of the plastics. The proportion of other fillers, such as Aerosil (pyrogenic silica), in injection-molded parts can vary considerably depending on the application and desired properties. These fillers are primarily glass fibers, carbon fibers, or similar materials. Thus, the combination of these fibers with the plastic creates a fiber-reinforced plastic component. The fibers used are primarily short fibers.

[0021] In another aspect of the present invention, a blank for the production of dental prostheses is provided by material processing using a CAD / CAM machine. The blank comprises a body made of a dental restorative material. This dental restorative material can be, for example, a ceramic, and in particular a zirconium ceramic. However, the present invention is not limited to a specific dental restorative material. The dental prosthesis(es) are then produced from the dental restorative material using the CAD / CAM machine. For this purpose, the blank has a holding attachment connected to the body for holding the blank within the CAD / CAM machine. The holding attachment defines the position of the blank within the CAD / CAM machine and enables movement of the blank through the CAD / CAM machine for processing.The holding element has a shape corresponding to the holder of the CAD / CAM machine, thus ensuring precise positioning of the blank body within the CAD / CAM machine. According to the invention, the blank has an identification chip for identifying the blank or the blank body. This identification chip can be located directly on the blank body or on the holding element.

[0022] Preferably, the blank is further formed based on the features described above.

[0023] The invention will now be explained in more detail with reference to preferred embodiments and the accompanying figures.

[0024] The figures show: Fig. 1 a blank according to the present invention and Fig. 2A, Fig. 2B a holding attachment according to the present invention.

[0025] The blank 10 according to the present invention comprises a retaining attachment 14 and a blank body 12 connected to the retaining attachment 14. The retaining attachment 10 includes a retaining pin 24, which is received in a corresponding receptacle of a CAD / CAM machine. Furthermore, the retaining attachment 14 includes a disc-shaped retaining element 16, wherein the retaining element 16 forms an end face 20 of the retaining attachment 14. The retaining pin 24 and the retaining element 16 are formed in one piece and are manufactured in a single manufacturing step, for example, by injection molding. The blank body 12 is connected to the end face 20 of the retaining element 16 and, in particular, bonded to it. According to the invention, the entire retaining attachment 14 is made of a plastic. In particular, the plastic is a polyamide, and especially PA6.To improve strength and component stiffness, the retaining element can incorporate fibers. These fibers could be, for example, carbon fibers, glass fibers, or similar materials. In particular, the fibers are typically short fibers. Furthermore, the plastic of the retaining element can contain glass beads to increase component stiffness.

[0026] As in the Fig. 2A and Fig. As shown in 2B, the holding attachment has 14 recesses 22A, 22B which specify an orientation of the blank body in the CAD / CAM machine.

[0027] As in the Fig. 2A and Fig.As shown in Figure 2B, the retaining element has a recess 18 in which an identification chip 26 is arranged. The identification chip has a wireless communication interface for wirelessly reading identification information from the identification chip. In particular, the identification chip 26 is designed as an RFID element. The recess 18 is formed in the end face 20 and extends into the retaining element 16 and, in particular, into the retaining pin 24. Especially if the retaining element 14 is made of plastic, the identification chip can be easily read from the outside. Due to the recess 18 being formed in the end face 20 of the retaining element 14, the recess 18 is closed when the retaining element 14 is connected to the blank body 12, thus ensuring that the identification chip 26 cannot be unintentionally separated from the blank. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] EP 0 160 797

[0002] EP 2 547 283 [0002, 0018]

Claims

[1] Blank for the production of dental components by material processing using a CAD / CAM machine, with a blank body made of a dental restoration material and a holding attachment connected to the blank body for holding the blank body in the CAD / CAM machine, the holding element is made of plastic. [2] Blank according to claim 1, characterized by , that the holding attachment has a circular cylindrical contour, with the axis defined by the cylinder axis passing through the center of the blank body. [3] blank according to claim 1 or 2, characterized by , that the holding attachment has an end face, wherein the blank body is connected to the end face of the holding attachment. [4] Blank according to one of claims 1 to 3, characterized bythat the blank body is bonded to the holding attachment and in particular to the end face, wherein the end face preferably has a surface roughness suitable for bonding. [5] Blank according to one of claims 1 to 3 characterized by an identification chip, wherein the identification chip is connected to the blank body or the holding attachment. [6] blank according to claim 5, characterized by that the identification chip is located inside the holding element. [7] blank according to claim 5 or 6, characterized by , that the identification chip is arranged in a recess on the front surface of the holding attachment and is covered by the blank body. [8] Blank according to any one of claims 1 to 7, characterized by a mark on the holding attachment and / or the blank body. [9] Blank according to any one of claims 1 to 8, characterized by that the plastic is a polyamide. [10] Blank according to any one of claims 1 to 9, characterized by , that the plastic of the retaining element contains 0% - 70% fillers. [11] Blank according to any one of claims 1 to 10, characterized by that the plastic of the retaining element contains fibers. [12] Blank for the production of dental components by material processing using a CAD / CAM machine, with a blank body made of a dental restoration material and a holding attachment connected to the blank body for holding the blank body in the CAD / CAM machine, characterized by through an identification chip for identifying the blank disc.

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