METHOD FOR PRODUCING A DENTAL PROSTHESIS BY FILLING A SPACE

Description

[0001] The invention relates to a method for manufacturing a dental prosthesis, such as a partial or complete dental prosthesis, as well as a dental prosthesis manufactured using such a method and a device for implementing the method.

[0002] Alongside traditional craftsmanship, digital manufacturing methods are gaining increasing importance in the dental field. For several years now, dental prostheses and other dental components, such as dentures, crowns, bridges, and bite splints, have been manufactured subtractively using CAD / CAM technologies in milling processes (CAM - Computer-Aided Manufacturing, CAD - Computer-Aided Design). CAD / CAM methods are also increasingly being used in the fabrication and design of partial and complete dentures with a denture base for resting on the gingiva and with attached or positioned denture teeth.

[0003] In the digital design of prosthetic work, especially partial or complete dentures, the construction is divided into a "white" or tooth-colored tooth component (the denture teeth) and a gum-colored ("pink") denture base component (the denture base). Dental prostheses therefore consist of a gum-colored or pink base and tooth-colored components (denture teeth or tooth segments).

[0004] There are methods, such as those known from DE 10 2009 056 752 A1 or WO 2013 / 124 452 A1, in which a partial or complete dental prosthesis is digitally set up and produced using CAD / CAM processes. Patent DE 103 04 757 B4 discloses a method for manufacturing dental prostheses in which the teeth are virtually set up in a virtual model and a prosthesis base is manufactured based on this virtual model. EP 2 742 906 A1 discloses a method in which a dental arch is connected to an impression material, the impression material being contained in a customized impression tray and containing an impression of the patient's oral cavity. The surface of the tray with the dental arch is digitized, and then a virtual model of the dental arch is computationally positioned and oriented as closely as possible within the virtual model of the prosthesis base.

[0005] In the context of digital total or partial dentures, denture teeth or tooth shapes are needed that can be bonded to the denture base in a clear and reproducible manner.

[0006] WO 2016 / 091 762 A1 discloses a method for manufacturing a dental prosthesis in which a template is produced with which several prosthesis teeth can be attached to a denture base in the desired position and orientation relative to each other. The prosthesis teeth are shortened by basal grinding in a cervical area to achieve the desired occlusal height. WO 2016 / 110 392 A1 discloses a method for manufacturing a dental prosthesis in which a plastically deformable connecting element is inserted into tooth sockets of a denture base to allow manual correction of the alignment of the prosthesis teeth in the denture base. DE 10 2008 019 694 B3 discloses a method and a device for manufacturing dental components from ceramics using a laser.From EP 2 571 451 B1 and EP 2 666 438 A2, methods for manufacturing dental prostheses are known in which prefabricated denture teeth are embedded in wax in a holder and then milled cervically using CAM technology. It is necessary to shorten the denture teeth basally (or cervically) to adapt the tooth height to the patient's jaw, i.e., to adjust the bite height of the denture to the patient's needs. WO 2014 / 159 436 A1 discloses a layered dental prosthesis with a reinforcement in the denture base, which is cast into a basal cavity. Besides dentures, other dental components such as occlusal splints can also be digitally manufactured using subtractive CAM processes based on patient data. A disadvantage of such occlusal splints is that they must have sufficient abrasion resistance, which reduces wearing comfort on the teeth.Furthermore, the possibility of aesthetically modifying bite splints is limited.

[0007] In both additive and subtractive manufacturing, joining the base and tooth-colored components (denture teeth) presents a significant challenge. This joining is typically achieved through bonding, but the quality of the transitions is prone to errors due to the use of too little or too much adhesive, as well as the correct positioning of the denture teeth during bonding. While available one-piece, two-color (gum-colored and tooth-colored) milled blanks offer excellent layer bonding, the aesthetics are always a compromise and therefore unsatisfactory due to the predetermined phase boundaries.

[0008] German patent DE 10 2017 117 4912 A1 discloses a method for producing a dental prosthesis in which a prosthesis base is milled in two steps and the prosthesis teeth are subsequently attached to the prosthesis base. US patent 2022 / 0110730 A1 discloses a two-part dental prosthesis in which a dental arch portion and a gingival portion are attached to each other via suitable structures. US patent 2022 / 0096217 A1 discloses an array device and an array method in which prosthesis teeth are attached to a dental prosthesis plate, whereby a body with recesses matching the prosthesis teeth and positioning sections facilitates the arrangement of the prosthesis teeth.

[0009] From DE 10 2017 113 814 A1 a method for manufacturing a dental prosthesis is known in which several basally processed prosthesis teeth are glued into a prosthesis base.

[0010] EP 3 593 756 A2 discloses a method in which denture teeth, provided with an allowance, are inserted into a subtractively machined denture base, also provided with an allowance, and bonded in place using a composite material / adhesive. Subsequently, the denture base and the bonded teeth are subtractively machined to remove the respective allowance and any excess composite material / adhesive.

[0011] US 2013 / 0101962 A1 discloses a method for manufacturing a dental prosthesis, in which several recesses are milled into a block along a dental arch. These recesses are filled with various types of resin, and the prosthetic teeth are fabricated from the resin that has hardened in the recesses. The block is then largely removed, and the prosthesis base is fabricated from the remaining material. This is a multi-stage milling process. Disadvantages of the method according to US 2013 / 0101962 A1 include significant material loss, the time required to remove material from the block, and the wear and tear on the tools used.From EP 2 915 503 B1, a reverse process for manufacturing a dental prosthesis is known, in which a milling blank made of enamel material is subtractively machined to create a cavity that serves as a negative mold for the base of the dental prosthesis. Subsequently, the occlusal and basal surfaces of the dental prosthesis are subtractively manufactured from this composite. This is also a multi-stage milling process. A disadvantage of the process according to EP 2 915 503 B1 is that very large quantities of the relatively hard enamel material and other materials must be removed to manufacture the dental prostheses. This not only results in the loss of a large amount of enamel material and other materials, but also places intensive demands on the milling tools, and the time required to implement the process is relatively long.

[0012] Furthermore, some of the injected gum-colored material must be removed after it has hardened in the cavity behind the enamel material. This further increases material consumption and, consequently, the time required for the procedure and the strain on the tools.

[0013] If a multi-stage process is chosen in which the prosthetic teeth and / or the prosthetic base are to be manufactured from several different materials, the material consumption and thus the time expenditure and tool stress are multiplied again.

[0014] Furthermore, if the enamel material is not completely removed from the outer surfaces (occlusal and oral sides) of the denture base, aesthetically displeasing white or tooth-colored remnants may remain, which then have to be manually removed by the dental technician. This, in turn, can lead to an unintended thinning of the denture base material.

[0015] Furthermore, a disadvantage of such methods is that either the denture teeth or the denture base must be made of castable plastics such as PMMA-based materials. This limits the choice of materials.

[0016] The following possibilities exist in the state of the art for the production of digitally designed total dentures: 1. Milling or printing the gum-colored base and bonding it to artificial teeth, or alternatively to milled or printed tooth-colored segments. Disadvantages include: manufacturing inaccuracies, time expenditure, aesthetic challenges due to excess adhesive or underfilling of marginal gaps, and limitations regarding the milling of cavities due to undercuts. 2. Milling prefabricated milling discs with an integrated two-phase structure. The aim here is to achieve a natural aesthetic through the skillful arrangement of the transitions. A disadvantage is the position of the transitions from gum-colored to tooth-colored, which always represents a compromise and is aesthetically unsatisfactory. 3. Milling pre-formed bodies into which prefabricated teeth are already integrated. With these methods, primarily only the basal side of the prosthesis is individually fabricated.The disadvantage of this method is that compatibility with individual patient cases is extremely limited, and many variations of pre-formed components must be kept in stock. 4. Layered construction of a prosthesis consisting of tooth-colored individual layers and a denture base by repeatedly milling and refilling the milled cavities. The disadvantages of this method are the significant material waste and the time required.

[0017] The object of the invention is to overcome the disadvantages of the prior art. In particular, it aims to provide a method for manufacturing a dental prosthesis, a dental prosthesis itself, and a device for manufacturing a dental prosthesis from at least two different and firmly bonded materials, enabling the rapid and resource-efficient production of dental components using subtractive CAM processes and, optionally, additional additive CAM processes. The method should require minimal material removal from both the material for the prosthetic teeth and the material for the prosthetic base. Specifically, the at least two materials should be able to be joined together within the process. The choice of materials should be as unrestricted as possible.In particular, it should be avoided that the denture teeth and the denture base consist entirely of a hardened, previously liquid plastic. The process should be as simple and straightforward as possible for the dental technician to implement. Specifically, fully automated or largely automated techniques such as CAD / CAM technologies should be used and available.

[0018] The problems of the invention are solved by a method according to claim 1, a dental prosthesis according to claim 14 and a device for implementing the method according to claim 15. Preferred variants are claimed by dependent claims 2 to 13 and 16.

[0019] The objects of the invention are thus solved by a method for manufacturing a dental prosthesis, wherein the dental prosthesis has several prosthetic teeth and a prosthetic base, wherein the prosthetic base has a gum-colored plastic and wherein the prosthetic teeth and the prosthetic base are firmly connected to each other in the method, wherein the method is characterized by the following steps: A) Providing a milling body for the production of denture teeth from a material suitable for denture teeth and providing a denture base preform, wherein the denture base preform has a retention structure on an oral side of the denture base preform; B) Producing a connection surface between the denture teeth and the denture base in a surface of the milling body using a subtractive CAM process according to a virtual three-dimensional model of the connection surface of the denture teeth to the denture base in the dental prosthesis, wherein the surface of the milling body is a flat surface; C) Producing a counter-retention structure in the surface of the milling body, wherein the counter-retention structure forms a counterpart to the retention structure of the denture base preform, or the milling body has the counter-retention structure matching the retention structure of the denture base preform;D) after steps A), B) and C), attaching the denture base preform with the support structure to the counter-support structure of the milling body, wherein the denture base preform is attached at a distance from the machined surface of the milling body except at the counter-support structure, so that an outwardly open gap is created between the denture base preform and the milling body; E1) after step D), filling at least one fluid polymerizable plastic or adhesive into the gap between the milling body and the denture base preform and into the volume removed in step B) from the surface of the milling body; and / or E2) before step D), applying at least one fluid polymerizable plastic or adhesive to an oral surface of the denture base preform and / or to the connection surface of the milling body produced in step B);F) after step E1) or after step E2) or after step D), curing or partial curing of the at least one fluid polymerizable plastic or adhesive, wherein, in the case of curing, a cured plastic material is formed in the space or, in the case of partial curing, a partially polymerized plastic material is formed in the space, wherein the cured plastic material or the partially polymerized plastic material firmly and flush connects the denture base preform to the material of the milling body; and G) after step F), subtractive machining of the cured or partially polymerized plastic material, the denture base preform and the milling body using a CAM process according to a virtual model of an outer surface of the dental prosthesis, so that the dental prosthesis is subtractively machined from the denture base preform, the cured or partially polymerized plastic material and the material of the milling body.

[0020] Steps A), B), C), D), F) and G) are mandatory in a method according to the invention, while either step E1) or step E2) or steps E1) and E2) must be performed in the method according to the invention. Preferably, either step E1) or step E2) is performed, and not both.

[0021] The material suitable for denture teeth is preferably a fully cured, tooth-colored plastic, but a suitable tooth-colored ceramic is also possible. Such materials for the fabrication of denture teeth are well known to dental professionals.

[0022] The material for the denture teeth (i.e., the material of the milling body or at least the part of the milling body from which the denture teeth are made), the at least one fluid polymerizable plastic or adhesive, the gum-colored plastic, and all other materials from which the denture base preform is made, must be biocompatible and suitable and approved for use in the patient's oral cavity.

[0023] It may be provided that the material for the prosthetic teeth is a plastic or a plastic composition, preferably a polymethyl methacrylate (PMMA) or a PMMA-containing plastic composition and / or a hot polymer.

[0024] A milling body within the meaning of the present invention is understood to be a solid body suitable for subtractive machining with milling tools and whose geometric dimensions are suitable for handling in CAM milling machines.

[0025] It may be designed that the denture base preform has no connecting surfaces intended for contact with the denture teeth. This ensures that the denture teeth are connected to the denture base preform via at least one fluid polymerizable resin or adhesive, and that sufficient space or gap is provided for this purpose.

[0026] It can also be provided that the gap has or provides a uniform gap dimension between the oral surface of the denture preform and the surface of the milling body machined in step B). For this purpose, the denture base preform on the oral side can be shaped according to the virtual three-dimensional model of the shape of the connecting surface of the denture teeth to the denture base in the dental prosthesis with an offset as a distance, preferably manufactured using an additive CAM process, and particularly preferably printed with a 3D printer.

[0027] The oral side and oral surface of the denture preform or dental prosthesis refers in this context to the surface / side facing the oral cavity, i.e., the surface / side facing away from the bearing surface on the gums.

[0028] Attaching the prosthesis base preform to the machined milling body in step D) can be done flexibly and regardless of location. This saves time.

[0029] It can be provided that the attachment of the prosthesis base preform to the machined milling body in step D) is carried out in a CAM device for implementing the CAM process in steps B) and G), wherein preferably the milling body remains fixed in the CAM device for implementing the CAM process in steps B) to G). Removing the machined milling body to attach the prosthesis base preform is not necessary. According to the invention, the CAM device can preferably be a milling machine, particularly preferably a computer-controlled multi-axis milling machine.

[0030] An outwardly open gap is understood to be a space that is open towards the environment of the system consisting of the milled body and the attached prosthetic base preform, so that the gap is accessible from the outside. This allows, for example, at least one fluid polymerizable plastic or adhesive to be poured into the gap from the outside.

[0031] If at least one fluid polymerizable plastic or adhesive has already been applied in a previous step E2), the gap can be partially or completely filled with the at least one fluid polymerizable plastic or adhesive applied in step E2) after the denture base preform has been attached to the machined milling body in step D).

[0032] Preferably, the denture base preform consists of, or is manufactured from, gum-colored plastic. Alternatively, it may be provided that a reinforcement, in particular a metallic reinforcement, is embedded in the gum-colored plastic.

[0033] In step G), the subtractive machining is preferably carried out such that the dental prosthesis is subtractively machined from the denture base preform, the cured or partially polymerized resin material, and the milling cutter material in such a way that the outer surface of the dental prosthesis, which forms the denture teeth, is formed from the milling cutter material, and the remaining outer surface, which forms the denture base, is formed from the material of the denture base preform and the cured or partially polymerized resin material. It may also be possible to take this into account accordingly in step B) during the machining of the milling cutter.

[0034] Furthermore, it may be provided that the filling of the at least one fluid polymerizable plastic or adhesive in step E1) is carried out by plugging and / or under overpressure, in particular in a pressure pot or in a pressure chamber with a pressure above normal pressure, preferably with a pressure of at least 150 kPa, particularly preferably with a pressure of at least 200 kPa, most preferably with a pressure of at least 200 kPa and at most 400 kPa.

[0035] It may also be provided that the filling of at least one fluid polymerizable plastic or adhesive in step E1) is carried out by plugging and / or under overpressure, in particular in a pressure pot or in a pressure chamber, with a pressure of at most 1,000 kPa, preferably with a pressure of at most 500 kPa, particularly preferably with a pressure of at most 400 kPa.

[0036] Furthermore, it can be provided that the curing or partial curing of the fluid polymerizable plastic in step F) is carried out by the application of heat and / or pressure, wherein the curing or partial curing preferably takes place over a period of time between 10 minutes and 120 minutes, particularly preferably between 30 minutes and 60 minutes.

[0037] It may also be provided that the curing or partial curing of the at least one fluid polymerizable plastic or adhesive in step F) is carried out by light curing, in particular by light polymerization.

[0038] It is possible to arrange the retention structure and the counter-retention structure in such a way that they are located within the volume of the dental prosthesis being manufactured. This means that the retention structure and the counter-retention structure are not visible on the surface of the dental prosthesis and cannot disrupt its structure.

[0039] It may be intended that the prosthesis base preform is attached to the counter-support structure of the milling body at a defined distance in step D). In this context, "defined distance" means that a defined and therefore predetermined distance is created or set between the prosthesis base preform and the machined surface of the milling body.

[0040] It may be provided that after step F) or after step G) a step H) is carried out in which the partially polymerized plastic material is cured to completion, in particular by light polymerization, wherein preferably following steps G) and H) a polishing of the surface of the dental prosthesis and / or a surface finishing of the dental prosthesis is carried out.

[0041] This results in a high final strength of the fully hardened plastic material and thus of the dental prosthesis, especially in the connection between the prosthesis teeth and the prosthesis base preform.

[0042] Furthermore, it can be provided that the milling body has a circumferential wall, wherein the circumferential wall of the milling body is maintained in steps B) to F), wherein preferably in step E1) the circumferential wall comes into contact with the at least one fluid polymerizable plastic or adhesive, particularly preferably the at least one fluid polymerizable plastic or adhesive is filled into the space in such a way that the level rises to the circumferential wall, but remains below the circumferential wall.

[0043] This makes the process easier for the user to carry out. The risk of contaminating the surrounding area with the fluid polymerizable plastic or adhesive is thus reduced.

[0044] Preferably, however, the process is carried out in such a way that the cavity created in step B) in the milling body is sufficient to receive the fluid polymerizable plastic or adhesive and to completely connect the prosthesis base preform with the milling body, without the fluid polymerizable plastic or adhesive escaping from the space via the unmachined surface of the milling body.

[0045] Furthermore, it may be provided that the prosthesis base preform is fixed to the milling body in step D), preferably with the support structure being glued to the counter-support structure on the milling body.

[0046] This ensures that the denture base preform does not float on the fluid polymerizable resin or adhesive, or is pushed away from the milling body when the fluid polymerizable resin or adhesive is poured into the space. This results in a defined thickness of the cured or partially polymerized resin between the denture base preform and the denture teeth milled from the milling body.

[0047] It may also be provided that the denture base preform consists at least partially or completely of a gum-colored plastic.

[0048] This ensures that the denture base can later be manufactured easily and without complex post-processing from the denture base preform and the hardened or partially polymerized resin. Furthermore, the denture base preform can thus be readily manufactured from the gum-colored resin using an additive manufacturing (CAM) process.

[0049] It may also preferably be provided that, prior to step A), the prosthesis base preform is manufactured using a CAM process based on the virtual three-dimensional model of a surface of a basal side of the prosthesis base of the dental prosthesis, in particular using an additive CAM process, wherein the basal side of the prosthesis base preform is preferably produced with an offset in the form of a basal material thickening.

[0050] This allows the denture base preform to be even better adapted to the shape of the denture base of the dental prosthesis to be manufactured and also largely individualized to the patient's needs. This saves time in the final subtractive CAM process in step G) and also reduces material consumption. The offset in the form of the basal material thickening ensures that the higher precision of the final subtractive CAM process, compared to the less precise additive CAM process, can be used to produce a high-quality dental prosthesis.

[0051] It may also be provided that a material reinforcement is provided during the manufacture of the prosthesis base preform, wherein the material reinforcement has a thickness of at least 0.1 mm compared to the surface of the virtual three-dimensional model of the dental prosthesis in the area of ​​the basal side of the prosthesis base, particularly preferably has a material reinforcement of at least 0.1 mm and a maximum of 2 mm, and most preferably has a material reinforcement of at least 0.3 mm and a maximum of 1 mm.

[0052] This ensures that sufficient excess material remains in step G), particularly on the basal side of the denture base preform, so that no material is missing or needs to be added after step G). This enables precise fabrication of the dental prosthesis using the more accurate subtractive CAM process.

[0053] It may be provided that no material reinforcement is provided for the support structure during the manufacture of the prosthesis base preform.

[0054] Since the gap is filled with the fluid polymerizable plastic or adhesive, no excess material from the denture base preform is needed at this point.

[0055] Furthermore, it may be provided that the denture base preform is pre-shaped at least on one basal side for resting on the gums, wherein the basal side is opposite the oral side, wherein preferably the denture base preform is or is pre-shaped on the basal side by a U-shaped depression to accommodate an edentulous jaw arch and / or is or is anatomically pre-shaped to fit the oral cavity situation of a patient.

[0056] This reduces the consumption of material for the prosthesis base preform in step G) and also the time required for processing in step G) and thus the wear of tools of the subtractive CAM device (such as the milling heads).

[0057] Furthermore, it can be provided that the support structure of the prosthesis base preform and the counter-support structure are realized in pairs by protruding pins and recesses matching the protruding pins, wherein preferably the protruding pins are inserted flush into the matching recesses in step D).

[0058] In this way, a simple, obvious and stable connection between the prosthesis base preform and the machined milling body is possible.

[0059] In a further development of the inventive method, it is also proposed that in step D) the prosthesis base preform is pressed against the milling body up to a stop, wherein the stop determines the distance in the space between the prosthesis base preform except at the counter-support structure to the machined surface of the milling body, wherein preferably the support structure of the prosthesis base preform and the counter-support structure of the milling body form the stop.

[0060] The stop ensures that the desired distance or gap between the prosthesis base preform and the machined surface of the milling body is automatically created during fastening in step D).

[0061] According to further training, it can be provided that the support structure of the denture base preform and the counter-support structure on the milling body are arranged within the dental prosthesis to be manufactured, preferably within a connection between the denture teeth and the denture base.

[0062] This ensures that the connection between the denture base preform and the milling body does not lie on a surface of the later dental prosthesis and cause a defect in the surface there.

[0063] It may also be provided that in step D) a defined distance is created between the prosthesis base preform and the machined surface of the milling body.

[0064] In this context, "defined spacing" means that a defined and therefore predetermined distance is created or set between the denture base preform and the machined surface of the milling cutter. This ensures that both the alignment of the denture base preform to the denture teeth and the size and shape of the gap are precisely adjusted, thus allowing the subtractive CAM machining in step G) to be performed to a lesser extent, which in turn saves working time and resources in the form of plastic and milling cutter wear.

[0065] Furthermore, it can be provided that in step D) a distance of at least 0.02 mm and a maximum of 2 mm is created between the prosthesis base preform and the machined surface of the milling body, preferably at least 0.02 mm and a maximum of 1 mm, particularly preferably at least 0.1 mm and a maximum of 1 mm, and most preferably at least 0.3 mm and a maximum of 1 mm.

[0066] The spacing applies to all areas except at the connection between the support structure and the counter-support structure.

[0067] These gaps ensure that the fluid polymerizable plastic or adhesive can be easily filled or packed into the space.

[0068] When performing step E2) without step E1), relatively small spacings between 0.02 mm and 0.5 mm are preferably chosen, preferably between 0.02 mm and 0.3 mm, and particularly preferably between 0.05 mm and 0.2 mm.

[0069] In contrast, when performing step E1) with or without step E2), relatively large spacings between 0.3 mm and 2 mm are preferably chosen, preferably between 0.3 mm and 1 mm, and particularly preferably between 0.5 mm and 1 mm.

[0070] Furthermore, it may be provided that in step E1) at least one fluid polymerizable plastic or adhesive is filled into the space to such a level that the connecting surface of the denture teeth and an oral surface of the denture base preform, which lies completely within the virtual model of the denture base, is completely wetted with the fluid polymerizable plastic.

[0071] This ensures that no air or gas inclusions are present in the dental prosthesis later on, and that a stable and form-fitting connection of the layers or parts of the dental prosthesis is achieved.

[0072] It is intended that the surface of the milling body, in which the connecting surface between the denture teeth and the denture base is produced in step B), is a flat surface.

[0073] This facilitates the subsequent filling or application of the fluid polymerizable plastic or adhesive. Furthermore, a standard blank can be used as a milling cutter.

[0074] According to a preferred embodiment, it can be provided that the cured plastic material or the partially polymerized plastic material, after complete curing, has material properties and / or color that differ from the gum-colored plastic of the denture base preform, wherein preferably the cured plastic material or the partially polymerized plastic material, after complete curing, has a hardness and / or transparency that differs from the gum-colored plastic of the denture base preform.

[0075] This allows the two-part structure of the denture base, consisting of the denture base preform and the hardened (and possibly previously partially polymerized) plastic material, which is created by curing from the fluid polymerizable plastic or adhesive, to be used to produce a particularly stable and / or aesthetically realistic dental prosthesis.

[0076] It may also be provided that in step G) the dental prosthesis is produced by subtractive machining of the prosthesis base preform and the material of the milling body from the prosthesis base preform, the hardened or partially polymerized plastic material and the material of the milling body, or in step G) the dental prosthesis is produced by subtractive machining of the prosthesis base preform, the hardened or partially polymerized plastic material and the material of the milling body from the prosthesis base preform, the hardened or partially polymerized plastic material and the material of the milling body.

[0077] This processing method allows for the fabrication of a particularly precise dental prosthesis based on the virtual three-dimensional model of the prosthesis. In the first case, the hardened or partially polymerized plastic material does not need to be processed. This is only possible if the shape in the milling cutter, created through suitable pre-forming using the subtractive CAM process, forms an exact negative mold of the prosthesis base in this area.

[0078] Furthermore, it can be provided that in step D) the prosthesis base preform is attached at a distance from the connecting surface of the milling body, preferably at a distance of at least 0.02 mm from the connecting surface of the milling body, particularly preferably at a distance of at least 0.02 mm and a maximum of 2 mm from the connecting surface of the milling body, and most preferably at a distance of at least 0.05 mm and a maximum of 1 mm from the connecting surface of the milling body.

[0079] The spacing applies to all areas except at the connection between the support structure and the counter-support structure.

[0080] These gaps ensure that the fluid polymerizable plastic or adhesive can be properly filled or packed into the space between the connecting surface of the milling body and the prosthesis base preform, or that there is a sufficient gap for applying the fluid polymerizable plastic or adhesive.

[0081] Furthermore, it may be provided that in step E1) the filling of the at least one fluid polymerizable plastic or adhesive into the space between the milling body and the denture base preform and into the volume removed in step B) from the surface of the milling body is carried out in such a way that the at least one fluid polymerizable plastic or adhesive bonds the milled milling body to the denture base preform, wherein preferably the at least one fluid polymerizable plastic or adhesive completely wets the surface of the milling body milled in step B) and a bonding surface on the oral side of the denture base preform and / or the space is completely filled with the at least one fluid polymerizable plastic or adhesive, in particular without gas inclusions.or in step E2) the application of the at least one fluid polymerizable plastic or adhesive to the oral surface of the denture base preform and / or to the connection surface of the milling body produced in step B), and in step D) the attachment of the denture base preform to the machined milling body in such a way that the at least one fluid polymerizable plastic or adhesive bonds the machined milling body to the denture base preform, wherein preferably the at least one fluid polymerizable plastic or adhesive completely wets the surface of the milling body machined in step B) and a bonding surface on the oral side of the denture base preform and / or the space between is completely filled, in particular without gas inclusions, with the at least one fluid polymerizable plastic or adhesive.

[0082] This ensures that no air or gas inclusions are present in the dental prosthesis later on, and that a stable and form-fitting connection of the layers or parts of the dental prosthesis is achieved.

[0083] According to further training, it can be provided that in step B) adjacent to the connecting surface between the prosthesis teeth and the prosthesis base, a recess is created in the surface of the milling body using the subtractive CAM method, preferably according to the virtual three-dimensional model of the surface of the dental prosthesis, wherein preferably the recess is created as a recess completely surrounding the connecting surface, particularly preferably a recess at least 0.5 mm wide and at most 10 mm wide completely surrounding the connecting surface.

[0084] This recess can be used in step E1) to be filled with at least one fluid polymerizable plastic or adhesive, or in step E2) to receive the at least one fluid polymerizable plastic or adhesive during application. This allows for a large-area bond between the milling body and the at least one fluid polymerizable plastic or adhesive. Furthermore, this facilitates filling or application, and the recess can receive the at least one fluid polymerizable plastic or adhesive.

[0085] Preferably, the depression can be a flow channel. Particularly preferably, the flow ring can be annular.

[0086] Furthermore, it may be provided that the at least one fluid polymerizable plastic or adhesive completely wets the surfaces of the milling body processed in step B) during filling in step E1) or during application in step E2) and / or wets the oral surface of the denture base preform at least partially, wherein preferably the milling body on the surface intended for processing with the subtractive CAM process and / or the denture base preform on the surface not to be wetted with the fluid polymerizable plastic or adhesive has a coating which prevents wetting with the at least one fluid polymerizable plastic or adhesive.

[0087] This ensures that all areas that will later lie within the dental prostheses are completely filled with the material of the milling body, the hardened or partially polymerized plastic material, and the material of the denture base preform.

[0088] It can also be provided that the oral side of the denture base preform is manufactured in the dental prosthesis according to the virtual three-dimensional model of the shape of the connecting surface of the denture teeth to the denture base, in particular using a CAM process or an additive CAM process, wherein preferably, when calculating the surface of the oral side of the denture base preform, volume is removed from the virtual three-dimensional outer shape of the denture base, particularly preferably with a thickness between 0.3 mm and 2 mm, most preferably with a thickness between 0.5 mm and 1 mm.

[0089] This allows for a defined gap or distance between the denture base and the denture teeth. This results in a uniform and stable connection between the denture base preform and the denture teeth.

[0090] Furthermore, it may be provided that in step G) the subtractive machining of the cured or partially polymerized plastic material, the denture base preform and the milling body is carried out from the direction of the underside of the milling body, which is opposite the surface of the milling body machined in step B), using the CAM method according to the occlusal surface and the oral surface of the virtual model of the dental prosthesis and / or in step G) subtractive machining of the cured or partially polymerized plastic material, the denture base preform and the milling body is carried out from the direction of the surface of the milling body machined in step B) using the CAM method according to the basal surface of the virtual model of the dental prosthesis.

[0091] This ensures that the respective surfaces are made from the desired materials of the milling body, the prosthesis base preform, and the hardened or partially polymerized plastic material.

[0092] It may be provided that after step B) a step B2) is carried out: B2) Cleaning and / or pretreating the surface of the milling body processed in step B) or the entire top surface containing the processed surface of the milling body, wherein preferably a chemical treatment of the surface of the first material is carried out during pretreatment, particularly preferably a chemical swelling of the surface of the first material with a monomer liquid, wherein the material of the milling body is a plastic composition containing a polymethyl methacrylate (PMMA) or consisting of a PMMA.

[0093] This creates a particularly stable bond between the first material and the cured or partially polymerized plastic material.

[0094] In a further embodiment of the present invention, it is proposed that the mounting structure of the prosthesis base preform and the counter-mounting structure form three defined contact points, so that when the prosthesis base preform is attached to the counter-mounting structure of the milling body with the mounting structure in step D), the prosthesis base preform is attached to the counter-mounting structure of the milling body via the three defined contact points of the mounting structure.

[0095] This three-point mounting ensures a stable, positionally and situally secure connection between the prosthesis base preform and the milling body.

[0096] Furthermore, it may be provided that light polymerization is carried out during curing or partial curing in step F), with a final curing by light polymerization preferably taking place after step G).

[0097] This allows for the simple production of a stable dental prosthesis with a secure connection between the denture teeth and the denture base preform. During light polymerization, the fluid polymerizable resin or adhesive may gel during partial curing.

[0098] It may further be provided that a cavity for receiving the fluid polymerizable plastic or adhesive is arranged on the surface of the milling body intended for processing with the subtractive CAM process, wherein the cavity has a bottom and the cavity is laterally bounded from the edge of the bottom by a circumferential wall, wherein the circumferential wall is annular and wherein the material suitable for prosthetic teeth forms the bottom and extends to a bottom of the milling body which is arranged opposite the top of the milling body.

[0099] This makes it easier to pour in at least one fluid polymerizable plastic or adhesive.

[0100] An annular wall according to the present invention has a recess that encloses the geometric center of the recess. Preferably, the recess is formed without undercuts and / or every point in the recess can be connected in a straight line to every other point in the recess, without the straight line running within the surrounding wall. Preferably, the recess is a compact geometric body.

[0101] The problems underlying the present invention are also solved by a dental prosthesis manufactured using a previously described method.

[0102] The dental prosthesis benefits from the advantages achieved through this process. It is therefore particularly cost-effective, time-saving, and produces little waste.

[0103] It may be provided that the denture base has a two-part structure, in which a subtractively machined denture base preform with a hardened or partially polymerized plastic material made of at least one fluid polymerizable plastic or adhesive is connected to the subtractively machined denture teeth, wherein preferably the surface of the hardened or partially polymerized plastic material is also subtractively machined.

[0104] The problems underlying the present invention are also solved by a device for implementing such a method, the device comprising a connection surface calculation module for calculating a connection surface between denture teeth and denture base according to a virtual three-dimensional model of a shape of the connection surface of the denture teeth to the denture base in the dental prosthesis; a denture base preform calculation module for calculating a virtual model of the surface of a denture base preform according to a virtual three-dimensional model of a shape of the connection surface of the denture teeth to the denture base and a basal side of the denture base of the dental prosthesis;a connection surface control module for a CAM device programmed to control the subtractive manufacturing of the connection surface calculated with the connection surface calculation module in a milling body; and a dental prosthesis control module for a CAM device programmed to control the subtractive manufacturing of the surface of the dental prosthesis to be manufactured according to the virtual model of an outer surface of the dental prosthesis.

[0105] The device can be a controller for a CAD / CAM system used to manufacture dental prostheses, whereby the device according to the invention is provided by suitable programming of the CAD / CAM system. A suitable CAD / CAM system known from the prior art for manufacturing a dental prosthesis can therefore be transformed into a device according to the invention by a software update with suitable programming.

[0106] The device may include a counter-support structure calculation module that calculates and positions a counter-support structure on the surface of the milling body relative to the connection surface and preferably within the connection surface, wherein the counter-support structure forms a counterpart to a support structure of a prosthesis base preform, and wherein the connection surface control module is preferably programmed for a CAM device to control the subtractive manufacturing of the connection surface calculated with the counter-support structure in the milling body.

[0107] The invention is based on the surprising finding that by using a prosthesis base preform, which is applied with positioning aids (in the form of support structures and counter-support structures) to an individually machined milling body (according to a virtual model of a connecting surface) for the production of prosthesis teeth and is connected with at least one fluid polymerizable plastic or adhesive, it is possible to create a precursor (or intermediate product) for the production of a dental prosthesis, from which a final individual dental prosthesis can be machined using a subtractive CAM process, without long machining times with heavy wear of the tools and large quantities of waste of the materials to be processed.This allows for the use of a space for filling or applying a fluid polymerizable resin or adhesive, thus minimizing the amount of fluid polymerizable resin or adhesive used. It is possible to fabricate large portions of both the denture teeth and the denture base, or even both parts entirely, from materials that are not made of a cured and previously fluid flowable resin (such as a powder-liquid PMMA).

[0108] The base geometry, which already roughly corresponds to the final dimensions, allows for significantly reduced material consumption. A wider range of materials can also be used; the limitation to PMMA no longer applies. Due to the reduced subtractive material removal, milling times can also be significantly reduced. Because the final milling only takes place after the components have been bonded or connected, the result corresponds with high accuracy to the digital data, i.e., the virtual three-dimensional model of the dental prosthesis to be manufactured.

[0109] The inventive method achieves a high degree of accuracy in the fit of the dental component by directly milling the final shape. This eliminates the need for bonding individual denture teeth and prevents inhomogeneities in the dental component resulting from a joining process. Simultaneously, complete curing of the milling cutter or the use of a particularly hard and strong cutter results in a highly abrasion-resistant material for denture teeth, while the use of a layered milling cutter yields a particularly aesthetically pleasing denture tooth material. In dental prostheses, a natural color transition from gum-colored to tooth-colored is achieved in the appropriate areas, eliminating the need for compromise. Particularly high aesthetics can be achieved by using multilayer milling cutters as a tooth-colored solid component.A particularly high-quality appearance of the manufactured dental prosthesis can be enhanced by ensuring that at least one fluid polymerizable plastic or adhesive has a different color and / or transparency and / or external appearance than the material of the prosthesis base preform.

[0110] The production of the dental components from the milling body, the cured fluid polymerizable plastic or adhesive, the denture base preform, and the method according to the invention can be carried out in a manufacturing process consisting of only two or three stages. Thus, a two-stage or three-stage process can be used to produce the dental components. Furthermore, no different shape variants of blanks or milling bodies are necessary. However, a very small set of milling blanks of varying sizes can also be used, or may even be advantageous.

[0111] An exemplary method according to the invention for manufacturing a dental prosthesis (complete dental prosthesis or partial dental prosthesis as a dental molded body) can have the following sequence: 1. Digital design of the prosthetic work and separation into multiple data segments. Data is required for the occlusal or oral upper surface, the basal underside of the dental prosthesis, and intermediate surface data consisting of the basal surface of the tooth-colored portions and the upper (oral) surface of the gingival-colored portions as the connecting surface. When creating the data for the occlusal or oral upper surface, an additional offset to the gingival-colored portions may need to be included in the CAD program. 2. Development of a suitable milling strategy for processing the individual process steps. Preferably, one-sided machining of the underside is performed, along with a zero-point shift appropriate to the milling cutter used, and preferably a further zero-point shift for machining both sides, with corresponding zero-point shifts for the upper and lower surfaces planned and subsequently carried out separately. 3.4. Mounting a milling body, at least the size of the tooth-colored portions, or a tooth-colored solid part of the milling body, in the milling machine and milling the intersurface data and the data for the occlusal or oral upper surface of the denture base from the basal side, optionally with a slight offset of the gingival portions (of the denture base) in the oral direction. The milling body or the tooth-colored solid part can preferably be provided with a position marker before positioning, which allows for repositioning. 5. Manufacturing the denture base preform using an additive CAM process according to the digital design, optionally with an offset to enlarge the basal side of the denture base preform and to reduce material on the oral side of the denture base preform compared to the denture base according to the virtual model of the dental prosthesis.Removal of the partially milled milling body and placement of the denture base preform onto the partially milled milling body using positioning aids to ensure correct alignment of the denture base preform on the partially milled milling body according to the digital design of the dental prosthesis, leaving a gap between the denture base preform and the partially milled milling body. 6. Filling of the gap or prior application to the surfaces of the denture base preform and / or the partially milled milling body that define the gap with a fluid polymerizable resin or adhesive (preferably a powder-liquid system) and polymerization using the analog manufacturing process. Afterwards, any necessary post-treatment of the cured resin material, such as water storage, is carried out. 7.Repositioning the filled, partially milled composite in the milling machine and milling the outer geometries basally and orally according to the final prosthesis design.

[0112] As a final step in the process, the surface of the dental prosthesis can be finished by polishing and / or chemical treatment.

[0113] The following are exemplary embodiments of the invention explained with reference to ten schematically represented figures and a flowchart, without, however, limiting the invention. These show: Figure 1 : a schematic perspective view of a virtual three-dimensional model of a prosthesis base; Figure 2 : a schematic perspective view of a virtual three-dimensional model of prosthetic teeth matching the prosthetic base according to Figure 1 ; Figure 3: a schematic perspective view of a virtual three-dimensional model of a milled body machined on one side with an integrated joining surface; Figure 4 : a schematic perspective view of a milled body machined on one side with an integrated joining surface; Figure 5 : a schematic perspective view of a prosthesis base preform; Figure 6 : a schematic perspective view of the milled body machined on one side with integrated joining surface according to Figure 4 with attached prosthetic base preform; Figure 7 : a schematic perspective view of a milling body machined on one side with an integrated connecting surface and a prosthesis base preform attached to it; Figure 8 : a schematic perspective view of the milled body machined on one side with integrated joining surface according to Figure 4with attached prosthetic base preform and filled with fluid polymerizable plastic; Figure 9 : a schematic perspective view of the oral side of the dental prosthesis machined from the milling body, the hardened plastic and the prosthesis base preform, which is still connected to the rest of the milling body via bridges; Figure 10 : a schematic perspective view of the dental prosthesis produced using the inventive method; and Figure 11 : the process of a method according to the invention for manufacturing a dental prosthesis.

[0114] The Figure 1 and 2 show a schematic perspective view of a virtual three-dimensional model of a prosthesis base 1 ( Figure 1 ) and on a virtual three-dimensional model of prosthetic teeth 4 ( Figure 2 ) matching the prosthesis base 1 according to Figure 1The virtual three-dimensional models of the denture base 1 and the denture teeth 4 can be computationally generated by file splitting of a virtual three-dimensional model of the dental prosthesis to be produced (see Figure 10 ) can be obtained. For this purpose, the outer shapes of the prosthetic teeth 4 and the prosthetic base 1 can be separated from each other in the CAD model, so that when they are reassembled, they form the complete dental prosthesis.

[0115] The contact surface between the denture base 1 and the denture teeth 4 is formed by a connecting surface 2, which may have the form of periodontal pockets in the denture base 1. On the basal sides 8 of the denture teeth 4, which are opposite the occlusal ends 6, there is a surface that fits flush with the connecting surface 2. The denture base 1 may have a palatal plate 3 if it is intended for the maxilla. A denture base for the mandible does not have a palatal plate.

[0116] The denture teeth 4 in the finished dental prosthesis should consist of a tooth-colored (whitish or cream-colored) hard plastic or a tooth-colored (whitish or cream-colored) hard ceramic, while the denture base 1 in the finished dental prosthesis should consist of a gum-colored (pink) plastic.

[0117] Figure 3shows a schematic perspective view of a virtual three-dimensional model of a milling body 10 machined on one side with an integrated joining surface 16 and Figure 4 shows a schematic perspective view of a milled body machined on one side with an integrated joining surface 26, which is machined according to the virtual three-dimensional model. Figure 3 was manufactured using a subtractive CAM process.

[0118] The virtual three-dimensional model of the milling body 10 machined on one side can be generated using a CAD method and contains the connecting surface 16, which corresponds to a virtual connecting surface 16 between denture teeth 4 and a denture base 1 in a virtual three-dimensional model of the dental prosthesis to be produced.

[0119] The virtual three-dimensional model of the milling body 10, machined on one side, is to be machined on a milling body surface 12. Accordingly, virtual three-dimensional surfaces are arranged as structures on this milling body surface 12.

[0120] A flow channel 14 can be provided around the connection surface 16, which is designed to receive fluid polymerizable plastic 40 (see Figure 8 ) or adhesive is provided. The flow channel 14 can be ring-shaped.

[0121] Furthermore, a virtual three-dimensional counter-support structure 18 in the form of three cylindrical holes can be arranged in the virtual three-dimensional model of the machined milling body 10. The counter-support structure 18 serves to attach a prosthesis base preform 30 (see Figure 5 ).

[0122] Using this virtual three-dimensional model of the machined milling body 10, the real milling body 20 is machined on a milling body surface 22 using a subtractive CAM process, and the structures are machined out or integrated according to the virtual three-dimensional model. The structures can accordingly include a flow channel 24, the connection surface 26, and a counter-support structure 28.

[0123] The milling body 20 can have a circumferential, annular wall 23. This circumferential, annular wall 23 allows the milling body surface 22 to be filled with the fluid polymerizable plastic 40 or adhesive beyond the flow channel 24, or can simply serve as a safety mechanism that prevents the fluid polymerizable plastic 40 or adhesive from escaping and contaminating the environment during filling or bonding.

[0124] Figure 5Figure 1 shows a schematic perspective view of a denture base preform 30. The denture base preform 30 has an oral surface 32 for connecting the denture teeth 54 or for connecting with the connecting surface 26 of the machined milling body 20.

[0125] The denture base preform 30 can be produced using a generative (additive) CAM process. A virtual three-dimensional model of the denture base 1 can be used as the input data set. An offset can be applied to remove volume from an oral side 36 of the virtual three-dimensional model of the denture base 1 to provide a space 39 or a gap between an oral surface 32 for connecting the denture teeth 54 (or the connecting surface 26) and the connecting surface 26. Furthermore, volume can be added to a basal side of the virtual three-dimensional model of the denture base 1 to ensure that sufficient material of the denture base preform 30 is present when the denture base 42, 52 (see Figure 9 and 10 ) is to be extracted subtractively from this area.

[0126] The denture base preform 30 has an oral side 36 and a basal side 38 for resting on the edentulous jaw. Except for any offset, the basal side 38 can already fit well with the basal side of the virtual model of the dental prosthesis or the denture base 1 of the dental prosthesis.

[0127] Retaining structures 34 can be arranged on the oral side 36 of the denture base preform 30. The retaining structures 34 are preferably designed to precisely match the counter-retaining structures 28 in position and shape. For this purpose, the retaining structures 34 and the counter-retaining structures 28 can be suitably designed in advance in the virtual three-dimensional CAD model of the denture base preform 30 and / or the machined surface 24, 26, 28 in the milling body 20. The retaining structures 34 can, for example, be designed as three cylindrical pins projecting at different locations. This allows for support against the machined milling body 20 at three points. This ensures precise positioning of the denture base preform 30 against the machined milling body 20.

[0128] To attach the prosthesis base preform 30 (see Figure 5 ) on the machined milling body 20 (see Figure 4The prosthesis base preform 30 and the machined milling body 20 can be connected to each other via the support structures 34 and the counter-support structures 28. This is shown in Figure 6 and Figure 7 shown are schematic perspective views of the milling body 20 machined on one side with integrated connecting surface 26 and with prosthesis base preform 30 attached to it.

[0129] The prosthesis base preform 30 can also be a prefabricated component that is suitable for a group of patients and has been selected accordingly. The three-dimensional shape of the oral side 36 or only the oral surface 32 is then preferably stored as a data set together with the retention structures 34 and can be taken into account during the construction of the virtual three-dimensional model of the surface 24, 26, 28 to be machined in the milling body or the basal connecting surface 26, so that a defined gap 39 with a defined gap dimension is created in the assembled state.

[0130] In any case, the prosthesis base preform 30 and the machined surface of the milling body 20 are manufactured such that, in the assembled state, a defined gap 39 with a defined gap dimension is created. The gap 39 can be adjusted according to the desired method of attachment of the prosthesis base preform 30 to the milling body 20 or to the prosthesis teeth 54 (see Figure 10The spacing should be adjusted accordingly. For example, if only a fluid polymerizable adhesive is to be used for bonding, which can be applied to the joining surface 26 and / or the oral surface 32 before assembly, a thin adhesive gap of between 0.02 mm and 0.3 mm may be sufficient. If a fluid polymerizable resin is to be filled, injected, or packed into the space 39 after the denture base preform 30 has been joined to the machined milling body 20, then a larger gap of between 0.1 mm and 2 mm is more appropriate.

[0131] This shows Figure 8 a schematic perspective view of the milled body machined on one side with integrated joining surface according to Figure 4with an attached denture base preform and fluid polymerizable resin 40 filled into the space 39. The fluid polymerizable resin 40 can be applied or injected either before or after the denture base preform 30 is attached to the milled body 20. The denture resin (1 or 2 components) can be prepared for this purpose and injected into the space 39. If necessary, certain areas can be pre-filled before the denture base preform 30 is attached. Before the fluid polymerizable resin 40 or adhesive oozes out, the assembly can be turned over and any excess can flow into the channel 24. Alternatively, instead of injection, fluid polymerizable resin 40 or adhesive can simply be applied and then the denture base preform 30 attached.

[0132] It may also be possible to create a filling bore (not shown) in the milling body 20. This can be done, for example, during the subtractive machining of the milling body surface 22 to produce the connection surface 28. The fluid polymerizable plastic 40 or adhesive can be injected into the space 39 through the filling bore. In a maxillary dental prosthesis 50 with a palatal plate, the filling bore can be located centrally; in a mandibular dental prosthesis, several filling bores can be arranged in an arc shape in the alveolar ridge area.

[0133] The fluid polymerizable resin 40 is then fully or partially cured in the space 39, so that the fluid polymerizable resin 40 firmly bonds the denture base preform 30 to the milled milling body 20. The resulting intermediate product can then be further processed. The denture base preform 30 can be fixed to the milling body 20 for this purpose. A flask can be used for this.

[0134] In the next step, the actual dental prosthesis 50 is manufactured according to the specifications of the virtual three-dimensional model of the dental prosthesis 50 from the in Figure 8 The intermediate product shown was machined using a subtractive CAM process. For this, the prosthesis base 42 initially remains connected to the remaining milling body 20 via bars 46. This situation is described in Figure 9 shown, with the view here directed towards the oral side 43 of the dental prosthesis. Figure 9The figure shows a schematic perspective view of the occlusal side of the dental prosthesis milled from the milling body 20, the hardened plastic 40, and the prosthesis base preform 30, which is still connected to the remaining milling body 20 via the bars 46. The milling body 20 is now also subtractively machined from the side opposite the previously machined milling body surface 22 (oral or occlusal) using the CAM process in order to mill the prosthesis teeth 44 from the material of the milling body 20. A recess 48 remains between the dental prosthesis 50 and the remaining milling body 20. The tooth segments produced from the milling body 20 remain in place.

[0135] In the next step, the bars 46 are removed, thus creating the finished dental prosthesis 50. This is shown below. Figure 10A schematic perspective view of the dental prosthesis 50 produced by the method according to the invention. The dental prosthesis 50 has a prosthesis base 52, which consists of the material of the prosthesis base preform 30 and the cured polymerizable plastic 40, and several prosthesis teeth 54, wherein the prosthesis teeth 54 consist of the material of the milling body 20. A basal side 58 of the dental prosthesis 50 is provided for resting on the edentulous gingiva and, if applicable, the palate of the patient.

[0136] The following is an example procedure based on the one associated with the Figures 1 to 10 The intermediate and final products shown are explained. The process of the exemplary procedure is described in Figure 11 schematically represented.

[0137] In a first step, 100, a virtual three-dimensional model of the dental prosthesis 50 to be produced is calculated using CAD.

[0138] In a subsequent second step 101, the connection surface 16 between the denture teeth 4 and the denture base 1 of the dental prosthesis is calculated in the virtual three-dimensional model. This can be done, for example, by splitting the virtual three-dimensional model of the dental prosthesis into a tooth portion and a denture base portion.

[0139] Subsequently, in a third work step 102, a calculation of the surface 24, 26, 28 to be produced in the milling body 20, having the connecting surface 16, 26, the counter-support structure 28 and, if applicable, the flow channel 24, is carried out using CAD methods.

[0140] Based on this, in a fourth work step 103, the surfaces 24, 26, 28 to be produced are manufactured in the milling body surface 22 in the milling body 20 using a subtractive CAM process. The joining surface 26 is also created using the CAM process.

[0141] In a fifth step 104, the prosthesis base preform 30 is manufactured or provided. The prosthesis base preform 30 may already exist, or it may be produced, for example, using an additive / generative CAM process according to the virtual three-dimensional model of the prosthesis base 1 (possibly with offset), as described above. For this purpose, the prosthesis base preform 30 can, for example, be printed from a plastic material.

[0142] In a sixth step 105, fluid polymerizable plastic 40 or adhesive can be applied to the prosthesis base preform 30 and / or the connection surface 26 in the milling body 20.

[0143] Alternatively, the seventh work step 106 can be carried out directly, in which the prosthesis base preform 30 is attached to the machined milling body 20.

[0144] In a subsequent eighth step 107, fluid polymerizable plastic 40 or adhesive is poured into the space 39 between the prosthesis base preform 30 and the machined milling body 20. Either the sixth step 105 or the eighth step 107 must be carried out, as can be seen from the flowchart. Figure 11 results.

[0145] In a ninth work step 108, the fluid polymerizable plastic 40 or adhesive is hardened or partially hardened, thus creating a firm connection between the machined milling body 20 and the prosthesis base preform 30.

[0146] In a tenth work step 109, the dental prosthesis 50 is subtractively extracted from the composite created in the ninth work step 108.

[0147] Optionally, in an eleventh step 110, the dental prosthesis 50 can then be post-hardened or final hardened.

[0148] In an optional twelfth step 111, the dental prosthesis 50 can undergo final processing, for example by surface treatment and / or polishing.

[0149] The features of the invention disclosed in the preceding description, as well as in the claims, figures and embodiments, can be essential for the realization of the invention in its various embodiments, both individually and in any combination. Reference symbol list

[0150] 1 Denture base (virtual model) 2 Connecting surface (virtual model) 3 Palatal plate (virtual model) 4 Denture teeth (virtual model) 6 Occlusal surface of the denture teeth (virtual model) 8 Basal side of the denture teeth (virtual model) 10 Single-sided milling body (virtual model) 12 Milling body surface (virtual model) 14 Flow groove (virtual model) 16 Connecting surface (virtual model) 18 Counter-retaining structure (virtual model) 20 Single-sided milling body 22 Surface of the milling body 23 Ring-shaped wall 24 Flow groove 26 Connecting surface 28 Counter-retaining structure 30 Denture base preform 32 Oral surface for connecting the denture teeth 34 Retaining structure 36 Oral side 38 Basal side 39 Interspace 40 Fluid polymerizable resin 42 Denture base 43 Oral side of the denture base 44 Denture teeth 46 Bar 48 Recess 50 Dental prosthesis 52 Denture base 54 Denture teeth 58 Basal side 100 Step: Calculationof a virtual 3D model of a dental prosthesis 101 Step: Calculation of a connection surface between prosthesis teeth and the prosthesis base of the dental prosthesis 102 Step: Calculation of the surface to be produced in a milling body, including the connection surface, using CAD methods 103 Step: Production of the surface to be produced in the milling body with the connection surface using CAM methods 104 Step: Production or provision of the prosthesis base preform 105 Step: Application of fluid polymerizable resin or adhesive to the prosthesis base preform and / or the connection surface in the milling body 106 Step: Attachment of the prosthesis base preform to the milled milling body 107 Step: Filling of fluid polymerizable resin or adhesive into a space between the prosthesis base preform and the milling body 108 Step: Curing of the fluid polymerizable resin orAdhesive 109 Step: Subtractive shaping of the dental prosthesis 110 Optional step: Post-curing or final curing of the dental prosthesis 111 Optional step: Final finishing of the dental prosthesis

Claims

1. A method for producing a dental prosthesis (50), wherein the dental prosthesis (50) has a plurality of prosthetic teeth (54) and a prosthesis base (52), wherein the prosthesis base (52) includes a gum-colored plastic and wherein the prosthetic teeth (54) and the prosthesis base (52) are firmly connected together in the method, wherein the method is characterized by the following steps: A) provision of a milling body (20) for producing the prosthetic teeth (54) from a material suitable for prosthetic teeth (54) and provision of a prosthesis base preform (30), wherein the prosthesis base preform (30) has a holding structure (34) on an oral side (36) of the prosthesis base preform (30); B) production of a connecting surface (26) between the prosthetic teeth (54) and the prosthesis base (52) in a surface (22) of the milling body (20) with the assistance of a subtractive CAM method in accordance with a virtual three-dimensional model of the connecting surface (16) of the prosthetic teeth (4) to the prosthesis base (1) in the dental prosthesis (50), wherein the surface (22) of the milling body (20) is a planar surface; C) production of a mating holding structure (28) in the surface (22) of the milling body (20), wherein the mating holding structure (28) forms a counterpart which fits with the holding structure (34) of the prosthesis base preform (30), or the milling body (20) has the mating holding structure (28) which fits with the holding structure (34) of the prosthesis base preform (30); D) after steps A), B), and C), attachment of the prosthesis base preform (30) with the holding structure (34) to the mating holding structure (28) of the milling body (20), wherein, apart from at the mating holding structure (28), the prosthesis base preform (30) is attached spaced apart from the machined surface (22) of the milling body (20) such that an interspace (39) open to the outside is obtained between the prosthesis base preform (30) and the milling body (20); E1) after step D), introduction of at least one fluid polymerizable plastic (40) or adhesive into the interspace (39) between the milling body (20) and the prosthesis base preform (30) and into the volume in the surface (22) of the milling body (20) machined away in step B); and / or E2) before step D), application of at least one fluid polymerizable plastic (40) or adhesive onto an oral surface (32) of the prosthesis base preform (30) and / or onto the connecting surface (26) produced in step B) of the milling body (20); F) after step E1) or after step E2) or after step D), curing or partial curing of the at least one fluid polymerizable plastic (40) or adhesive, wherein, on curing, a cured plastics material is obtained in the interspace (39) or, on partial curing, a partially polymerized plastics material is obtained in the interspace (39), wherein the cured plastics material or the partially polymerized plastics material connects the prosthesis base preform (30) firmly and flush to the material of the milling body (20); and G) after step F), subtractive machining of the cured or partially polymerized plastics material, the prosthesis base preform (30) and the milling body (20) by a CAM method in accordance with a virtual model of an outer surface of the dental prosthesis (50), such that the dental prosthesis (50) is subtractively carved out from the prosthesis base preform (30), the cured or partially polymerized plastics material and the material of the milling body (20).

2. The method according to Claim 1, characterized in that after step F) or after step G), a step H) proceeds in which the partially polymerized plastics material is finally cured, in particular is finally cured by photopolymerization, wherein, subsequent to step G) and H), polishing of the surface of the dental prosthesis (50) and / or surface finishing of the dental prosthesis (50) is carried out, and / or photopolymerization is carried out on curing or partial curing in step F), wherein final curing by photopolymerization preferably proceeds after step G), and / or the cured plastics material or the partially polymerized plastics material once completely cured has material properties and / or a color which deviate from the gum-colored plastic of the prosthesis base preform (30), wherein the cured plastics material or the partially polymerized plastics material once completely cured preferably has a hardness and / or transparency which deviate from the gum-colored plastic of the prosthesis base preform (30).

3. The method according to any one of the preceding claims, characterized in that the milling body (20) has a surrounding wall, wherein the surrounding wall of the milling body (20) is retained in steps B) to F), wherein in step E1) the surrounding wall preferably comes into contact with the at least one fluid polymerizable plastic (40) or adhesive, particularly preferably the at least one fluid polymerizable plastic (40) or adhesive is introduced into the interspace (39) such that the level rises up to the surrounding wall, but below the surrounding wall, and / or the prosthesis base preform (30) is fixed to the milling body (20) in step D), preferably is adhesively bonded to the milling body (20) with the holding structure (34) on the mating holding structure (28), wherein particular preferably the prosthesis base preform (30) consists at least in part or completely of a gum-colored plastic.

4. The method according to any one of the preceding claims, characterized in that the prosthesis base preform (30) is produced before step A) by a CAM method, in particular by an additive CAM method, on the basis of the virtual three-dimensional model of a surface of a basal side of the prosthesis base (52) of the dental prosthesis (50), wherein the basal side of the prosthesis base preform (30) is preferably produced with an offset in the form of a basal material thickening, wherein particular preferably a material thickening is provided in the production of the prosthesis base preform (30), wherein the material thickening has a thickness of at least 0.1 mm in comparison with the surface of the virtual three-dimensional model of the dental prosthesis (50) in the region of the basal side of the prosthesis base (52), particularly preferably a material thickening of at least 0.1 mm and at most 2 mm, and very particularly preferably a material thickening of at least 0.3 mm and at most 1 mm.

5. The method according to any one of the preceding claims, characterized in that the prosthesis base preform (30) is preformed at least on a basal side (38) to lie against gums, wherein the basal side (38) is opposite the oral side (36), wherein the prosthesis base preform (30) preferably is or has been preformed on the basal side (38) with a U-shaped indentation for receiving a toothless mandibular arch and / or is or has been preformed to fit anatomically with the situation in a patient's oral cavity, and / or in step D), the prosthesis base preform (30) is pressed against the milling body (20) until a limit stop is reached, wherein, apart from at the mating holding structure (28), the limit stop determines the spacing in the interspace (39) between the prosthesis base preform (30) and the machined surface (22) of the milling body (20), wherein the holding structure (34) of the prosthesis base preform (30) and the mating holding structure (28) of the milling body (20) preferably form the limit stop.

6. The method according to any one of the preceding claims, characterized in that the holding structure (34) of the prosthesis base preform (30) and the mating holding structure (28) are implemented in pairs by projecting posts and recesses which fit with the projecting posts, wherein in step D) the projecting posts are preferably inserted flush into the recesses fitting therewith, and / or the holding structure (34) of the prosthesis base preform (30) and the mating holding structure are arranged on the milling body (20) within dental prosthesis (50) to be produced, preferably are arranged within a connection between the prosthetic teeth (54) and the prosthesis base (52).

7. The method according to any one of the preceding claims, characterized in that a defined spacing of the prosthesis base preform (30) from the machined surface (22) of the milling body (20) is produced in step D), and / or a spacing of the prosthesis base preform (30) from the machined surface (22) of the milling body (20) of at least 0.02 mm and at most 2 mm, preferably of at least 0.02 mm and at most 1 mm, particularly preferably of at least 0.1 mm and at most 1 mm, and very particularly preferably of at least 0.3 mm and at most 1 mm is produced in step D), and / or the prosthesis base preform (30) is attached spaced apart from the connecting surface (26) of the milling body (20) in step D), preferably with a spacing of at least 0.02 mm from the connecting surface (26) of the milling body (20), particularly preferably with a spacing of at least 0.02 mm and at most 2 mm from the connecting surface (26) of the milling body (20), and very particularly preferably with a spacing of at least 0.05 mm and at most 1 mm from the connecting surface (26) of the milling body (20).

8. The method according to any one of the preceding claims, characterized in that the at least one fluid polymerizable plastic (40) or adhesive is filled in step E1) at least to such a filling level in the interspace (39) that the connecting surface (26) of the prosthetic teeth (54) and an oral surface (32) of the prosthesis base preform (30), which is completely located within the virtual model of the prosthesis base (1), is completely wetted with the fluid polymerizable plastic (40).

9. The method according to any one of the preceding claims, characterized in that the dental prosthesis (50) is carved in step G) by subtractive machining of the prosthesis base preform (30) and the material of the milling body (20) from the prosthesis base preform (30), the cured or partially polymerized plastics material and the material of the milling body (20) or the dental prosthesis (50) is carved in step G) by subtractive machining of the prosthesis base preform (30), the cured or partially polymerized plastics material and the material of the milling body (20) from the prosthesis base preform (30), the cured or partially polymerized plastics material and the material of the milling body (20).

10. The method according to any one of the preceding claims, characterized in that the introduction in step E1) of the at least one fluid polymerizable plastic (40) or adhesive into the interspace (39) between the milling body (20) and the prosthesis base preform (30) and into the volume in the surface (22) of the milling body (20) machined away in step B) proceeds such that the at least one fluid polymerizable plastic (40) or adhesive connects the machined milling body (20) to the prosthesis base preform (30), wherein preferably the at least one fluid polymerizable plastic (40) or adhesive completely wets the surface (22) of the milling body (20) machined in step B) and an attachment face on the oral side of the prosthesis base preform (30) and / or the interspace (39) is completely filled, in particular without entrapped gas, with the at least one fluid polymerizable plastic (40) or adhesive, or in step E2) application of the at least one fluid polymerizable plastic (40) or adhesive onto the oral surface (32) of the prosthesis base preform (30) and / or onto the connecting surface (26) of the milling body (20) produced in step B), and in step D) attachment of the prosthesis base preform (30) to the machined milling body (20) proceeds such that the at least one fluid polymerizable plastic (40) or adhesive connects the machined milling body (20) to the prosthesis base preform (30), wherein preferably the at least one fluid polymerizable plastic (40) or adhesive completely wets the surface (22) of the milling body (20) machined in step B) and an attachment face on the oral side (36) of the prosthesis base preform (30) and / or the interspace (39) is completely filled, in particular without entrapped gas, with the at least one fluid polymerizable plastic (40) or adhesive, wherein in both cases it can preferably be provided, that the at least one fluid polymerizable plastic (40) or adhesive, on introduction in step E1) or on application in step E2), completely wets the surfaces of the milling body (20) machined in step B) and / or wets the oral surface (32) of the prosthesis base preform (30) at least in places, wherein preferably the milling body (20) has, on the surface intended for machining by the subtractive CAM method, and / or the prosthesis base preform (30) has, on the surface which is not to be wetted with the fluid polymerizable plastic (40) or adhesive, a coating which prevents wetting with the at least one fluid polymerizable plastic (40) or adhesive.

11. The method according to any one of the preceding claims, characterized in that an indentation in the surface (22) of the milling body (20) is made in step B) adjacent to the connecting surface (26) between the prosthetic teeth (54) and the prosthesis base (52) with the assistance of the subtractive CAM method, preferably in accordance with the virtual three-dimensional model of the surface of the dental prosthesis (50), wherein the indentation is preferably produced as an indentation completely surrounding the connecting surface (26), particularly preferably as an indentation of a width of at least 0.5 mm and at most 10 mm completely surrounding the connecting surface (26), and / or the oral side (36) of the prosthesis base preform (30) is produced in accordance with the virtual three-dimensional model of the shape of the connecting surface (16) of the prosthetic teeth (4) to the prosthesis base (1) in the dental prosthesis (50), in particular by a CAM method or an additive CAM method, wherein, on calculation of the surface of the oral side (36) of the prosthesis base preform (30), volume is preferably removed from the virtual three-dimensional outer shape of the prosthesis base (1), particularly preferably with a thickness of between 0.3 mm and 2 mm, and very particularly preferably with a thickness of between 0.5 mm and 1 mm.

12. The method according to any one of the preceding claims, characterized in that subtractive machining of the cured or partially polymerized plastics material, the prosthesis base preform (30) and the milling body (20) proceeds in step G) from the direction of the underside of the milling body (20), which is opposite the surface (22) of the milling body (20) machined in step B), by the CAM method in accordance with the occlusal surface and the oral surface of the virtual model of the dental prosthesis (50) and / or subtractive machining of the cured or partially polymerized plastics material, the prosthesis base preform (30) and the milling body (20) proceeds in step G) from the direction of the surface (22) of the milling body (20) machined in step B) by the CAM method in accordance with the basal surface of the virtual model of the dental prosthesis (50).

13. The method according to any one of the preceding claims, characterized in that the holding structure (34) of the prosthesis base preform (30) and the mating holding structure (28) form three defined contact points, such that, on attachment of the prosthesis base preform (30) with the holding structure (34) to the mating holding structure (28) of the milling body (20) in step D), the prosthesis base preform (30) is attached to the mating holding structure (28) of the milling body (20) via the three defined contact points of the holding structure (34), and / or a cavity for receiving the fluid polymerizable plastic (40) or adhesive is arranged on the surface (22) of the milling body (20) intended for machining by the subtractive CAM method, wherein the cavity has a bottom and, starting from the edge of the bottom, is laterally bounded by a surrounding wall (23), wherein the surrounding wall (23) is annular and wherein the material suitable for prosthetic teeth (54) forms the bottom and extends to an underside of the milling body (20) which is arranged opposite the upper side of the milling body (20).

14. A dental prosthesis (50) produced with a method according to any one of the preceding claims, characterized in that the prosthesis base (52) has a two-part structure, in which a subtractively machined prosthesis base preform (30) with a plastics material cured or partially polymerized from at least one fluid polymerizable plastic (40) or adhesive is connected to the subtractively machined prosthetic teeth (54), wherein the surface of the cured or partially polymerized plastics material is preferably likewise subtractively machined.

15. A device for implementing the method according to any one of claims 1 to 13, the device comprising a connecting surface calculation module for calculating a connecting surface (26) between prosthetic teeth (54) and prosthesis base (52) in accordance with a virtual three-dimensional model of a shape of the connecting surface (16) of the prosthetic teeth (4) to the prosthesis base (1) in the dental prosthesis (50); a prosthesis base preform calculation module for calculating a virtual model of the surface of a prosthesis base preform (30) in accordance with a virtual three-dimensional model of a shape of the connecting surface (16) of the prosthetic teeth (4) to the prosthesis base (1) and a basal side of the prosthesis base (1) of the dental prosthesis (50); a connecting surface control module for a CAM device programmed to control the subtractive production of the connecting surface (26), calculated with the connecting surface calculation module, in a milling body (20); and a dental prosthesis control module for a CAM device programmed to control the subtractive production of the surface of the dental prosthesis (50) to be produced in accordance with the virtual model of an outer surface of the dental prosthesis (50).

16. The device according to Claim 15, characterized in that the device has a mating holding structure calculation module which calculates and positions a mating holding structure (28) in the surface (22) of the milling body (20) relative to the connecting surface (26) and preferably within the connecting surface (26), wherein the mating holding structure (28) forms a counterpart which fits with a holding structure (34) of a prosthesis base preform (30), wherein the connecting surface control module for a CAM device is preferably programmed to control the subtractive production of the connecting surface (26) to the mating holding structure (28) in the milling body (20) calculated with the connecting surface calculation module and the mating holding structure calculation module.