Method, apparatus and system for producing dental prostheses by jet printing

Abstract

The invention relates to a method, an apparatus and a system for producing dental prostheses by jet printing. The invention provides a method for producing a dental restoration by jet printing, comprising the steps of: jet printing (S101) one or more layers of a dental restoration by means of a ceramic slurry; jet printing (S102) a coloring solution onto the one or more layers; and applying (S103) a fixing solution for fixing the coloring solution.

Description

Technical Field

[0001] The present invention relates to a method for producing dental restorations by inkjet printing and a production device for producing dental restorations by inkjet printing. Background Art

[0002] When manually coloring ceramic restorations made of zirconia, separate coloring is performed using a nitrate infiltration solution. For example, they are applied to the surface of the restoration using a brush and then diffuse into the porous ceramic. This application requires a high level of experience from the dental technician.

[0003] The coloring process of zirconia white bodies can be automated by infiltrating into the restoration under computer control using an airbrush (spray gun) system. In the additive manufacturing process, inkjet can be used to selectively apply different-colored solvent-based ceramic slurries. Processing highly filled ceramic slurries places high demands on the printheads used in terms of particle size, filling level, and viscosity and wear. Inkjet printing (jetting) of aqueous slurries is an alternative to solvent-based slurries. Here, the jetted material layer is dried without cracks.

[0004] However, during the manual infiltration process, the salt solution diffuses into the zirconia white body in an uncontrolled manner. If the material is applied layer by layer and combined with the layer-by-layer selective coloring of the previously applied ceramic layer, the previously deposited nitrates will dissolve again in the underlying layer and continue to diffuse uncontrollably into the produced ceramic body. Summary of the Invention

[0005] The technical task of the present invention is to prevent the uncontrolled diffusion or flow of a nitrate solution used as a coloring solution that is selectively applied during the spatial layer construction process.

[0006] This task is solved by the subject matter of the present invention.

[0007] According to a first aspect, this technical task is solved by a method for producing dental restorations by inkjet printing, the method comprising the steps of: inkjet printing one or more layers of the dental restoration with a ceramic slurry; inkjet printing a coloring solution onto the one or more layers; and applying a fixing solution for fixing the coloring solution. This can prevent the uncontrolled diffusion or flow of the nitrate solution used as a coloring solution that is selectively applied during the layer construction process. Ensure controlled, selective coloring of the 3D printed green body using the coloring solution during the additive manufacturing process. The selective material application and selective coloring of the slurry are performed separately. The same or different printheads can be used for material application and coloring. The fixing solution, for example, prevents the coloring solution from diffusing on the aqueous slurry to produce a multi-colored green body. For example, this can ensure controlled, selective coloring of the 3D printed ZrO2 green body using the coloring solution during the additive manufacturing process.

[0008] In a technically advantageous embodiment of the method, the fixing solution is sprayed onto one or more layers. This achieves the technical advantage that the fixing solution can be applied quickly and over a large area, for example.

[0009] In a further technically advantageous embodiment of the method, the fixing solution is jet-printed onto one or more layers by means of a print head. This achieves the technical advantage that the fixing solution can be applied selectively with precise accuracy, for example.

[0010] In a further technically advantageous embodiment of the method, the one or more layers are dried before or after jet-printing the coloring solution. This achieves the technical advantage of reducing the diffusion of the coloring solution, for example.

[0011] In a further technically advantageous embodiment of the method, the one or more layers are dried before or after applying the fixing solution. This also achieves technical advantages such as reducing the diffusion of the coloring solution.

[0012] In a further technically advantageous embodiment of the method, the pH of the fixing solution is greater than 7. This achieves the technical advantage of effectively reducing the flow of the coloring solution, for example.

[0013] In a further technically advantageous embodiment of the method, the fixing solution is an ammonia-ammonium chloride solution. This achieves the technical advantage that the coloring solution is locally fixed, for example.

[0014] In a further technically advantageous embodiment of the method, the steps of producing a dental restoration are repeated. This achieves the technical advantage that an entire dental restoration can be constructed and colored, for example.

[0015] In a further technically advantageous embodiment of the method, the dental restoration is sintered in a sintering furnace. This achieves the technical advantage that a dental restoration with high strength can be produced, for example.

[0016] According to a second aspect, this technical task is solved by a production device for producing a dental restoration by jet-printing, the production device comprising a first print head for jet-printing one or more layers of the dental restoration by means of a ceramic slurry; and a second print head for jet-printing a coloring solution onto the one or more layers; and an application device for applying a fixing solution for fixing the coloring solution. The production device achieves the same technical advantages as the method according to the first aspect.

[0017] In a technically advantageous embodiment of the production device, the application device is formed by a nozzle for applying the fixing solution extensively. This achieves the technical advantage that the fixing solution can be applied quickly and over a large area, for example.

[0018] In a further technically advantageous embodiment of the production device, the application device is formed by a print head for selectively applying a fixing solution. This achieves the technical advantage that the fixing solution can be selectively applied with precise accuracy, for example.

[0019] In a further technically advantageous embodiment of the production device, the production device includes a storage container for the fixing solution. The storage container can be replaceable. This achieves the technical advantage that the fixing solution can be stored and easily replaced, for example.

[0020] In a further technically advantageous embodiment of the production device, the production device includes a drying device for drying the applied materials such as the slurry layer, the coloring solution, the fixing solution. This achieves the technical advantage that further spreading can be reduced, for example.

[0021] In a further technically advantageous embodiment of the drying device, the drying device includes a blower and / or an infrared radiator. This achieves the technical advantage that the layer can be quickly dried, for example.

[0022] According to a third aspect, this technical task is solved by an inkjet printing system, which includes a production device for producing dental restorations by inkjet printing; a coloring solution for printing onto one or more layers; and a fixing solution for fixing the coloring solution. The inkjet printing system achieves the same technical advantages as the method according to the first aspect.

[0023] In a technically advantageous embodiment of the inkjet printing system, the coloring solution and / or the fixing solution are stored in a container. This achieves the technical advantage that the solution can be reliably stored, for example.

[0024] In a further technically advantageous embodiment of the inkjet printing system, the container is replaceable. This achieves the technical advantage that the solution can be easily exchanged, for example. Description of the Drawings

[0025] Exemplary embodiments of the present invention are shown in the drawings and described in more detail below, where:

[0026] Figure 1 A diagram showing different regions of an incisor tooth is shown;

[0027] Figure 2 A schematic diagram of a dental restoration is shown;

[0028] Figure 3 A schematic diagram of a production device for producing dental restorations is shown;

[0029] Figure 4 A schematic diagram of a method for producing dental restorations by inkjet printing is shown;

[0030] Figure 5 Schematic illustration of a further method for producing dental prostheses by jet printing;

[0031] Figure 6 Table showing the composition of different coloring solutions; and

[0032] Figure 7 Block diagram showing a method for producing dental prostheses. DETAILED DESCRIPTION

[0033] Figure 1 Illustration showing different regions of a tooth 105. The tooth 105 includes an inner dentin core 101 and an outer enamel 103. The opaque, i.e., non-transparent, dentin core 101 is responsible for the basic coloring of the tooth 105. This shines through the enamel 103 at the incisal edge. The enamel 103 is naturally semi-transparent. Semi-transparency is the partial transmissibility of an object to light. In order to make the dental prosthesis look as realistic as possible, this structure of the tooth 105 is also used for artificial dental prostheses. For this purpose, materials with different optical properties are used in the production of dental prostheses.

[0034] Figure 2 Schematic illustration of a dental prosthesis 100. The dental prosthesis 100 serves as a dental prosthesis and is formed, for example, by a dental bridge, a dental crown, a complete or partial prosthesis. The dental prosthesis 100 is selectively constructed layer by layer from 1 - n different ceramic slurries 109, for example, by means of a jet printing process, and after the final sintering of the white body of the dental prosthesis 100 produced in this way using nitrates such as Fe 2 O 3 , Cr 2 O 3 , Mn 2 O 3 , Tb 2 O 3 , Pr 2 O 3 , Er 2 O 3 , Co 3 O 4 , NiO, TiO 2 , CeO 2 and / or by using doping, for example, with yttrium for selective coloring layer by layer and after the final sintering of the white body of the dental prosthesis 100 produced in this way, the corresponding characterization of color, semi-transparency, opacity, and mechanical properties is obtained.

[0035] In this process, the dental prosthesis 100 is constructed from successive layers printed on top of each other. The ceramic powder of the slurry 109 can already be provided with a predetermined semi-transparency. Mixing these slurries 109 results in the dental prosthesis 100 having the desired semi-transparency in the corresponding spatial regions.

[0036] After selectively applying a layer of paste 109 by means of an inkjet printing process, the layer is dried by evaporating the solvent or water acting as a binder without cracking. What remains is a porous white body layer with a layer thickness of 1 μm to 50 μm and a density of at least 2.5 g / cm 3 This process is repeated until the entire dental prosthesis 100 is spatially constructed in layers.

[0037] In the case of the ZrO 2 paste 109, different yttrium-doped ceramic powders (3 mol% yttrium - 3Y-TZP, 4 mol% yttrium - 4Y-TZP, 5 mol% yttrium - 5Y-TZP) can also be used for different strengths. In this process, yttrium doping also affects the degree of translucency. Different yttrium-doped ceramic powders have different properties.

[0038] 3Y-TZP = low translucency / high strength

[0039] 4Y-TZP = medium translucency / medium strength

[0040] 5Y-TZP = high translucency / low strength

[0041] However, if different pre-colored pastes 109 are used, and all of these pastes also have different translucencies and / or mechanical properties, each of these pastes 109 is assigned its own print head 111-1. For example, if a universal CYMK color scheme is used to cover the entire color space, 3×4 = 12 pastes 109 are included in 12 print heads. The production of these different pastes 109 is also complex. These large quantities of pastes 109 are stored and maintained as different items.

[0042] Figure 3 A schematic diagram of a production device 200 for producing a dental prosthesis 100 by inkjet printing (spray printing) of an aqueous-based or solvent-based paste 109 is shown. In order to additively manufacture ceramic, dental multi-materials, and multi-color prostheses 100 by means of inkjet printing, the base paste 109 is processed.

[0043] The production device 200 includes a plurality of storage containers 119-1 in which base pastes 109 with different optical properties are arranged. In addition, the production device 200 includes at least a plurality of storage containers 119-2 for accommodating the coloring solution 107. Additionally, the production device 200 includes a storage container 119-3 in which a fixing solution 115 is accommodated. A production device for producing a dental prosthesis by inkjet printing; a coloring solution for printing onto one or more layers; and a fixing solution for fixing the coloring solution together form an inkjet printing system.

[0044] The ceramic slurries 109 are each applied drop by drop by means of the designated printhead 111-1 in a plurality of layers 117-1, 117-2, ……, 117-n in order to spatially build the dental restoration 100 layer by layer. The printhead 111-1 can move in two directions so that the slurry 109 can be printed at any position. One or more printheads can also be fixedly arranged, and the build platform moves in three spatial directions under the printhead.

[0045] The slurry 109 with a droplet volume typically of 10 to 100 pL is used for selective material application, which eliminates the time-consuming debinding process. For example, an electro-controlled piezoelectric element is used to eject the droplets.

[0046] Another printhead 111-2 is used to apply the coloring solution 107, through which the coloring solution 107 can be jet-printed onto one or more of the layers 117-1, ..., 117-n. The printhead 111-2 can also move in two directions so that the coloring solution 107 can be printed at any position. The printheads 111-1 and 111-2 can be controlled independently of each other or integrated in a common print module. The printheads 111-1 and 111-2 can also be fixedly arranged, and the build platform moves in three spatial directions under the printheads.

[0047] The fixing solution 115 is applied by a further application device 121, which can be formed by a nozzle for widely applying the fixing solution 115 or by a further printhead for selectively applying the fixing solution 115.

[0048] A drying device 123 is provided for drying the aqueous materials, by means of which the layers 117-1, ……, 117-n, the coloring solution 107 and the fixing solution 115 can be dried without cracks. The drying device 123 is formed, for example, by a blower and / or an infrared radiator.

[0049] The production device 200 provides a reduced number of pre-colored and yttrium-doped neutral base slurries 109 to minimize the number of printheads 111-1 and 111-2 and still achieve the aesthetic and functional results of the dental restoration 100. The coloring is completed individually by selectively applying the coloring solution 107.

[0050] The desired tooth color is composed and mixed by the pre-colored coloring solution 107. A subtractive color system is used, which spans a limited dental color space (dental color gamut). These pre-colored slurries 109 are then created by mixing, three-dimensional halftoning or dithering in various ratios of colors in a limited dental color space (color gamut) that covers common tooth colors but not all colors.

[0051] The different coloring solutions 107 are selectively applied to layers 117-1, ……, 117-n using a 3D dithering algorithm performed by a dithering module. For this purpose, the dithering module includes a processor for performing the 3D dithering algorithm and a digital data memory for storing the calculated mixing ratios and the dithering algorithm. The processor includes any hardware system, component, or mechanism for processing data, signals, or other information. The processor may include a system having a central processing unit (CPU), multiple data processing units (MPU), a dedicated circuit for implementing functions, or other systems. The data memory may include a hard disk, a flash memory card, a random access memory (RAM), or a read-only memory (ROM).

[0052] During dithering, using an inkjet printing process, different coloring solutions are selectively applied onto a printing plane at a certain ratio and a two-dimensional printing pattern is formed. The 3D dithering algorithm also calculates different two-dimensional dithering patterns to be applied in a plurality of layers 117-1, ……, 117-n on top of each other. This can prevent optical artifacts such as streaks or moiré patterns from appearing on vertical surfaces. These pre-colored slurries 109 with various ratios of color mixing, three-dimensional halftoning, or dithering are created in a limited dental color space (color gamut) that covers common tooth colors, but not all colors.

[0053] When using a highly viscous slurry 109 with a viscosity greater than 100 mPas and a high filling, special requirements are imposed on the print head 111-1 and its fluid system. The print head 111-1 is compatible with the binder and / or the carrier material of the slurry 109 used to avoid incompatibilities and consequences such as corrosion on the print head.

[0054] After selectively applying the slurry 109 to the layers 117-1, ……, 117-n by means of an inkjet printing process, the layers 117-1, ……, 117-n are dried without cracks by evaporating the solvent or water that acts as a binder. The ceramic powder of the slurry 109 may already be colored in a certain color, such as a base color or a tooth color. What remains is a porous white body layer with a thickness of 1 μm to 50 μm and a density of at least 2.5 g / cm 3 ³. This process is repeated until the entire dental restoration 100 is spatially constructed in layers.

[0055] If there are two slurries 109 with different translucencies, a high-strength and opaque slurry 109 can be used for the dentin core, and a normal-strength and highly translucent slurry 109 can be used for the incisal edge. After the 1-n layers 117-1, ……, 117-n of material application, selective coloring is performed by selectively jet-printing a coloring solution, such as a nitrate solution (acid), according to the corresponding color coding or color information.

[0056] Figure 4 A schematic view of a method for producing a dental prosthesis 100 by jet printing is shown. In step S201, first, a layer-by-layer selective material application of a slurry 109 is performed on 1 - n layers 117 - 1, ……, 117 - n by means of a jet printing process (inkjet process).

[0057] In step S202, the applied slurry layer is dried, for example, by supplying hot air. In step S203, the first to nth applied layers 117 - 1, ……, 117 - n (green layers) of the slurry 109 are selectively colored by means of a coloring solution. Here, the coloring solution is also printed onto the first to nth applied layers 117 - 1, ……, 117 - n by means of jet printing. In step S204, the printed coloring solution is locally fixed by means of a fixing solution, that is, by means of an alkaline solution (alkali solution) with a pH greater than 7. Then steps S201 to S204 are repeated until the dental prosthesis 100 is completely constructed in space.

[0058] For this method, an aqueous-based slurry or a solvent-based slurry 109 can be processed. The selective material application (step S201) and the selective coloring (step S203) are carried out separately. The technical advantage of this method is that for the dried layers, that is, the anhydrous layers 117 - 1, ……, 117 - n, the pH of the coloring solution hardly plays a role.

[0059] Figure 5 A schematic view of another method for producing a dental prosthesis 100 by jet printing is shown. In step S301, first, a layer-by-layer selective material application of an alkaline slurry 109 is performed on 1 - n layers by means of a jet printing process (inkjet process).

[0060] The alkaline slurry 109 has a pH greater than 7. A conventional alkaline slurry 109 contains H 2 O, a dispersion aid, such as 0 to 5% by weight, preferably 0.01 to 5% by weight of a carboxylic acid derivative (citric acid) or 0 to 5% by weight of ammonium polyacrylate (NH 4 PAA), preferably 0.01 to 5% by weight. The pH (8 - 11) can be adjusted with NH 4 OH. The advantage of adjusting the alkalinity of the slurry 109 is that the ceramic slurry 109 shows less corrosion to the metal components of the print head.

[0061] In step S302, the still wet and undried applied layers 117 - 1, ……, 117 - n (green layers) of the slurry 109 are selectively colored by means of a coloring solution. Once nitric acid (the coloring solution) comes into contact with the wet slurry 109, precipitation occurs.

[0062] In step S303, the coloring solution is automatically fixed by contacting with the alkaline paste 109. In step S304, the wet-on-wet coloring layers 117-1, ……, 117-n are dried, for example, by supplying hot air without cracks. Then steps S301 to S304 are repeated until the dental prosthesis 100 is spatially constructed.

[0063] For this method, an aqueous-based paste or a solvent-based paste 109 can be processed. Selective material application (step S301) and selective coloring (step S302) are carried out separately.

[0064] If the alkaline paste 109 is not used, the coloring solution 107 diffuses into the layers 117-1, ……, 117-n. The applied coloring solution is fixed by separately applying a fixing solution such as an alkaline solution.

[0065] During this process, the paste 109 is stabilized within an acidic pH range. After printing and drying the respective individual layers, an alkaline fixing solution, such as 0.1N ammonium hydroxide solution, is first applied. Then the coloring solution 107 is applied. When the coloring solution impinges on the layer treated with the fixing solution, the pH of the coloring solution locally shifts to pH>2. As the pH of the coloring solution changes, metal hydroxides, such as Fe(OH) 3 . This process is called precipitation or flocculation.

[0066] After printing and drying the respective individual layers, the coloring solution can also be applied, followed immediately by an alkaline fixing solution, thereby fixing the coloring components at the desired positions.

[0067] Figure 6 A table showing compositions with different coloring solutions 107 is presented. The coloring solution 107 has a low viscosity and can be jet-printed using an inkjet print head with DOD technology or bubble jet technology. The print head can integrate multiple color channels for multi-color printing. The print head can apply the coloring solution to the layers 117-1, ……, 117-n at a high resolution of 720 dpi.

[0068] In the case of six available print heads, only one print head is used for the media translucency paste 109 and one print head is used for the support material. For seven available print heads, two print heads are respectively used for the opaque paste 109 and the highly translucent paste 109, and one print head is used for the support material. The other four print heads are used for the coloring solution 107.

[0069] The coloring solution is an aqueous-based nitrate or chloride salt solution. Various metal salts (e.g., Fe(NO 3 ) 3*9H 2 O; Pr(NO 3 ) 3 *6H 2 O; Tb(NO 3 ) 3 *5H 2 O; Er(NO 3 ) 3 *5H 2 O; Mn(NO 3 ) 2 *4H 2 O; Co(NO 3 ) 2 *6H 2 O; Cr(NO 3 ) 3 *9H 2 O; Mg(NO 3 ) 2 *6H 2 O; Al(NO 3 ) 3 *9H 2 O; Cu(NO 3 ) 2 *3H 2 O; Zn(NO 3 ) 2 *6H 2 O; Y(NO 3 ) 3 *6H 2 O; La(NO 3 ) 3 *6H 2 O; Ce(NO 3 ) 3 *6H 2 O; Nd(NO 3 ) 3 *6H 2 O; Sm(NO 3 ) 3 *6H 2 O; Gd(NO 3 ) 3 *6H 2 O; Yb(NO 3 ) 3 *6H 2 O; Ni(NO 3 ) 2 *6H 2 O; Co(NO 3 ) 2 *6H 2 O; Ga(NO 3 ) 3*xH 2 O; In(NO 3 ) 3 xH 2 O) is dissolved into different concentrations.

[0070] However, depending on the desired composition, the coloring solution 107 can also be significantly more concentrated. However, increasing the ion concentration increases the viscosity or shifts the pH value into the acidic range (<7).

[0071] Figure 7 A block diagram of a method for producing a dental prosthesis 100 by inkjet printing is shown. In step S101, layers 117-1, …, 117-n of the dental prosthesis 100 are inkjet printed with the ceramic slurry 109. In step S102, the coloring solution 107 is inkjet printed onto one or more of the layers 117-1, …, 117-n. Then, in step S103, a fixing solution 115 is applied to fix the coloring solution 107. These steps are repeated until the dental prosthesis 100 is completely constructed.

[0072] If the coloring solution 107 is inkjet printed into previously dried layers 117-1, …, 117-n and then a wet slurry is applied again onto the previously dried and colored layers 117-1, …, 117-n, it is possible that the coloring solution 107 dissolves again and diffuses uncontrollably in the already constructed dental prosthesis 100. When the coloring solution 107 is inkjet printed onto the dried layers 117-1, …, 117-n, care must be taken to ensure that the penetration depth of the coloring solution 107 can be controlled. For example, if the penetration depth is greater than the layer thickness, coloring can only occur after multiple layers of the slurry 109 have been applied.

[0073] By applying the fixing solution 115, the coloring solution 107 is locally fixed, thereby preventing uncontrolled diffusion or mixing by precipitation of hydroxides. This can be done by applying an alkaline fixing solution 115 (such as an ammonia-ammonium chloride buffer solution) over a large area or selectively to change the pH. For example, the ammonia-ammonium chloride buffer solution includes 987.8 g of water, 6.8 g of 25%-ammonia, and 5.4 g of ammonium chloride.

[0074] A single slurry 109 with a base color and medium translucency can be used for applying the additive material of the dental prosthesis 100. Selective coloring of the slurry 109 is achieved by inkjet printing a coloring solution, which is then fixed.

[0075] Due to the different rheological properties of the slurry 109 and the coloring solution 107, different printhead technologies can be used. The slurry 109 is highly viscous (10 - 1000 mPas, depending on the shear rate) and contains abrasive fillers in the form of ceramic particles in a high weight / volume ratio. A low viscosity of the slurry 109 between 10 - 500 mPas is advantageous, and a viscosity between 10 - 100 mPas is even more favorable. The higher the viscosity of the slurry 109, the more difficult it is to process using an inkjet printhead. The printhead should also be able to eject an aqueous medium.

[0076] On the other hand, the coloring solution 107 has a low viscosity (0.5 - 50 mPas). Since these are high - concentration nitrate solutions, the printhead used should be nitrate - resistant. Additionally, the volume processed in each case is different, with the volume ratio of the slurry 109 being approximately 98% and the volume ratio of the coloring solution 107 being approximately 2%. A multi - channel printhead 111 - 2 can also be used to perform the selective application of the coloring solution 107.

[0077] The penetration or diffusion depth of the coloring solution 107 can also be controlled by adjusting the viscosity. This is done by adding a suitable thickening agent to the coloring solution 107, which is stable within the pH range of the coloring solution, such as polyvinylpyrrolidone (PVP).

[0078] The major volume is processed via the slurry 109, while the smaller volume is processed through the coloring solution 107. The coloring solution 107 and the slurry 109 can be stored in storage containers 119 - 1 and 119 - 2 of different sizes.

[0079] The fully - formed dental restoration 100 is then sintered in a sintering furnace. The slurry 109 and the coloring solution 107 can be adjusted to have a uniform sintering behavior. The sintering kinetics can be uniformly adjusted by adjusting the individual coloring solution 107. The sintering activator is "neutralized" by using or adding a sintering inhibitor.

[0080] The nitrate solution can be used as the coloring solution 107 for the selective coloring process, regardless of whether the slurry 109 has been pre - colored or the coloring is carried out only by the layer - by - layer selective application of the coloring solution 107 during the additive (layer - by - layer production process).

[0081] Additionally, the opacity of the slurry 109 of the dental restoration 100 can be adjusted using variable components of yttrium or ytterbium in the coloring liquid. For example, the elements yttrium, ytterbium, neodymium, and europium are used as translucency enhancers, and aluminum and silicon are used as opaque liquids. A suitable coloring solution can be used to increase the yttrium content. In this way, different opacity values can be achieved in the dental restoration 100, such as being opaque for the dentin core and translucent for the incisal edge.

[0082] All features explained and shown in connection with the various embodiments of the present invention can be provided in different combinations in the subject matter of the present invention in order to achieve their advantageous effects simultaneously.

[0083] All method steps can be implemented by means suitable for performing the respective method steps. All functions performed by the features of the subject matter can be method steps of a method.

[0084] The scope of protection of the present invention is given by the claims and is not limited by the features explained in the description or shown in the drawings.

[0085] List of reference numerals

[0086] 100 Dental prosthesis

[0087] 101 Dentin core

[0088] 102 Intermediate region

[0089] 103 Enamel

[0090] 105 Tooth

[0091] 107 Coloring solution

[0092] 109 Slurry

[0093] 111-1, 111-2 Print heads

[0094] 115 Fixing solution

[0095] 117-1, 117-2, 117-n Layers

[0096] 119-1, 119-2, 119-3 Storage containers

[0097] 121 Application device

[0098] 123 Drying device

[0099] 200 Production device.

Claims

1. A method for producing a dental restoration by jet printing, comprising the following steps: - printing one or more layers of the dental restoration by means of ceramic slurry jetting; - jet printing a coloring solution onto the one or more layers; as well as - Apply a fixing solution to fix the coloring solution.

2. The method according to claim 1, wherein: The fixing solution is sprayed onto the one or more layers.

3. The method according to claim 1, wherein: The fixing solution is jet-printed onto the one or more layers by means of a print head.

4. A method according to any one of the preceding claims, wherein: The one or more layers are dried before or after jet printing the coloring solution.

5. A method according to any one of the preceding claims, wherein: The one or more layers are dried before or after applying the fixing solution.

6. A method according to any one of the preceding claims, wherein: The pH of the fixing solution is greater than 7.

7. A method according to any one of the preceding claims, wherein: The fixing solution is an ammonia-ammonium chloride solution.

8. A method according to any one of the preceding claims, wherein: The steps of producing the dental restoration are repeated.

9. A method according to any one of the preceding claims, wherein: The dental restoration is sintered in a sintering furnace.

10. A production device for producing a dental restoration by jet printing, comprising: - a first print head for jet printing one or more layers of the dental restoration by means of a ceramic slurry; and - a second print head for jet printing a coloring solution onto the one or more layers; as well as - an application device for applying a fixing solution for fixing the coloring solution.

11. The production device according to claim 10, wherein: The application device is formed by a spray head for widespread application of the fixing solution.

12. The production device according to claim 10 or 11, wherein: The application device is formed by a print head for selectively applying the fixing solution.

13. The production device according to any one of claims 10 to 12, wherein: The production plant comprises a storage container for the fixing solution.

14. The production device according to any one of claims 10 to 13, wherein: The production plant comprises a drying device for drying the applied material.

15. The production device according to any one of claims 10 to 14, wherein: The drying device comprises a blower and / or an infrared radiator.

16. Inkjet printing system, including: - a production device for producing dental restorations by inkjet printing; - a coloring solution for printing onto one or more layers; as well as - A fixing solution for fixing the coloring solution.

17. The jet printing system according to claim 16, wherein: The coloring solution and / or the fixing solution are stored in a container.

18. The jet printing system according to claim 17, wherein: The container is replaceable.

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