Manufacturing method for dental object

Abstract

To improve the manufacturing of a dental object.SOLUTION: A manufacturing method for a dental object (100) includes a step (S101) for printing a dental object using a manufacturing material and a support structure layer by layer using a meltable support material, a step (S102) for melting the support material, and a step (S103) for absorbing the melted support material into the manufacturing material of the printed dental object.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a dental object and to a manufacturing system for manufacturing a dental object layer by layer. [Background technology]

[0002] When manufacturing dental objects using a 3D printing process, the printed dental object undergoes time-consuming polishing after the sintering process. Because the material becomes very hard after sintering, a large amount of polishing is required. Therefore, it is advantageous to polish the object before sintering. Polishing in this state is easier and more time-saving. The thickness of the support and manufacturing material layers is not chosen too thick, as this slows down the printing speed. Higher printing resolution shortens the polishing time but increases the printing time. Thinner layers reduce surface roughness depending on the curvature. Summary of the Invention [Problem to be solved by the invention]

[0003] The technical problem of the present invention is to improve the production of dental objects. [Means for solving the problem]

[0004] This technical problem is solved by the subject matter of the independent claims. Technically advantageous embodiments are the subject matter of the dependent claims, the description and the drawings.

[0005] According to a first aspect, the technical problem is solved by a method for producing a dental object, the method comprising the steps of printing a dental object layer by layer with a production material and a support structure layer by layer with a meltable support material, melting the support material, and absorbing the melted support material into the production material of the printed dental object. Absorption can be achieved by infiltration of the melted support material or by automatic absorption due to inevitable penetration by capillary forces.

[0006] The support material absorbed into the porous matrix of the manufacturing material achieves the technical advantage that, for example, the dental object can be more easily handled, ground, and polished, resulting in a smoother surface that can be automatically produced. This method can, for example, save the time that would normally be spent polishing a printed and subsequently thermally compressed (sintered) dental object. Wax infiltration provides the green dental object with the necessary base strength to allow polishing to be performed in the green state.

[0007] In a technically advantageous embodiment of the method, the manufacturing material comprises an oxide ceramic material, thereby achieving the technical advantage that a manufacturing material that is particularly suitable for, for example, dental objects is used.

[0008] In a further technically advantageous embodiment of the method, the support material comprises a wax and / or a nonionic surfactant. Waxes are classified into three main groups depending on their origin: natural waxes (further classified into vegetable waxes, animal waxes, mineral waxes, and petrochemical waxes), chemically modified waxes, and synthetic waxes. In the present invention, petrochemical waxes, such as kerosene wax (hard kerosene), petrolatum, microwax (microkerosene), and mixtures thereof, are preferably used, and kerosene wax is particularly preferred. Vegetable waxes such as candelilla wax, carnauba wax, Japan wax, espartograss wax, cork wax, guaruma wax, rice germ oil wax, sugarcane wax, ouricury wax, and montan wax can also be used; animal waxes such as beeswax, shellac wax, spermaceti, lanolin (wool wax), and brush grease; mineral waxes such as ceresin and ozokerite (earth wax); chemically modified waxes such as montan ester wax, sazol wax, and hydrogenated jojoba wax, or synthetic waxes such as polyalkylene waxes and polyethylene glycol waxes. Nonionic surfactants include, for example, fatty alcohol ethoxylates, fatty alcohol propoxylates, alkyl glucosides, alkyl polyglucosides, octyl phenoethoxylates, and nonyl phenoethoxylates. This provides technical advantages, such as a lower melting point of the support material.

[0009] In a further technically advantageous embodiment of the method, after melting, the supporting material is maintained at a predetermined temperature for a predetermined infiltration time. The dental object can also be maintained at this temperature. This achieves the technical advantage of, for example, facilitating the infiltration of the supporting material into a porous dental object. The porous dental object is made of individual particles, and a dense molding is formed by stacking individual layers and then drying them.

[0010] In a further technically advantageous embodiment of the method, the dental object is cooled or the temperature of the dental object is reduced after infiltration of the support material. This achieves the technical advantage of, for example, increasing the processing speed of the method. The advantage of cooling is that it increases the strength of the printed dental object. This makes it easier to handle and polish the dental object without causing cracks, peeling, or damage.

[0011] In a further technically advantageous embodiment of the method, the dental object is ground or polished after infiltration with the supporting material, thereby achieving the technical advantage of, for example, producing a smooth surface of the dental object in the raw state.

[0012] In a further technically advantageous embodiment of the method, after printing the layer, the production material and / or the support material is hardened and / or dried, thereby achieving the technical advantage that, for example, the production of dental objects is accelerated.

[0013] In a further technically advantageous embodiment of the method, the curing and / or drying of the manufacturing and support materials is carried out by means of electromagnetic radiation, heat, air currents, convection, evaporation and / or chemical reactions, thereby achieving the technical advantage that, for example, the curing of the manufacturing and support materials can be carried out particularly efficiently.

[0014] In a further technically advantageous embodiment of the method, the molten support material only partially penetrates the dental object, thereby achieving the technical advantage that, for example, only the outer layer of the dental object is penetrated with support material, the support material can be saved and subsequent processes, such as sintering and debinding, can be carried out more quickly.

[0015] In a further technically advantageous embodiment of the method, the support material comprises a doping material which changes the properties of the dental object during sintering. The doping material can be, for example, in ionic dissolved form (Y 3+ , La 3+ , Ce 3+ , Ce 4+, Fe 3+ , Er 3+ yttrium, lanthanum, iron, manganese, chromium, erbium, terbium, praseodymium, neodymium, cobalt, nickel, titanium, etc.) or as nanoparticles in the form of oxides smaller than 100 nm (Y2O3, Tb2O3, Mn2O3, Fe2O3, Pr2O3, Er2O3). This achieves the technical advantage that, for example, the optical properties and compression behavior of the dental object can be further improved in a subsequent sintering process.

[0016] In a further technically advantageous embodiment of the method, the support material has an average particle size d 50 The glass or glaze material or glass or glaze nanomaterial has a temperature of 1000 to 1300°C. 2.5 Viscosity greater than 10 Pa·s. Glass or glaze materials usually have a viscosity of 10 Pa·s at 1450°C. 9 The preferred glass or glaze material has a viscosity of less than 10 Pa·s at 950°C. 4 Pa·s, preferably 10 5.6 Pa·s, particularly preferably 10 7 Viscosity of 10 Pa·s at 1300°C 4 Preferred viscosity of 10 Pa·s at 1450°C 7 Less than Pa·s, preferably 10 5.6 It has a viscosity of less than Pa·s, which has the technical advantage that capillary forces in the printed dental object form a thin layer of glass or glaze material on the surface, forming a dense glaze layer when the dental object is finally sintered to its maximum density.

[0017] In a further technically advantageous embodiment of the method, the dental object is a crown, a bridge, an abutment, a veneer, an inlay, an onlay, a tabletop, a partial or a complete prosthesis, whereby the technical advantage is achieved, for example, that a particularly suitable dental object is produced.

[0018] In a further technically advantageous embodiment of the method, the support material is melted in the printer or on the build platform after printing. The wax infiltration or melting can also be performed outside the printer, for example, in an oven. This achieves the technical advantage of, for example, immediate absorption of the support material.

[0019] According to a second aspect, the technical problem is solved by a manufacturing system for the layer-by-layer manufacturing of dental objects, comprising a print head for printing the dental object layer-by-layer from a manufacturing material and the support structure layer-by-layer from a meltable support material, and a melting device for melting the support material, which achieves the same technical advantages as the method according to the first aspect.

[0020] In a technically advantageous embodiment of the manufacturing system, the melting device is configured to keep the supporting material at a predetermined temperature for a predetermined infiltration time, thereby achieving technical advantages such as easier infiltration of the supporting material into the dental object.

[0021] In a further technically advantageous embodiment of the manufacturing system, the manufacturing system comprises a cooling device for cooling the dental objects, whereby technical advantages are achieved, for example, in that the processing speed of the manufacturing system is increased.

[0022] In a further technically advantageous embodiment of the manufacturing system, the manufacturing system comprises a finishing device for grinding or polishing the dental object, whereby the technical advantage is achieved that, for example, particularly smooth surfaces of the dental object can be manufactured using the manufacturing system.

[0023] An embodiment of the invention is shown in the drawings and is explained in more detail below. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a schematic diagram of a manufacturing system for manufacturing dental objects. [Figure 2]FIG. 2 is a further schematic diagram of a manufacturing system for manufacturing dental objects. [Figure 3] FIG. 1 is a block diagram of a method for manufacturing a dental object. DETAILED DESCRIPTION OF THE INVENTION

[0025] FIG. 1 shows a schematic diagram of a manufacturing system 200 for producing a printed dental object 100. The dental object 100 may be, for example, a crown, bridge, abutment, veneer, inlay, onlay, tabletop, partial, or complete prosthesis. Such dental objects 100, which are worn in a patient's mouth, should have a smooth surface; otherwise, they are less comfortable to wear. A rough surface of the dental object 100 also promotes the growth of undesirable biofilms, resulting in more noticeable discoloration.

[0026] For manufacturing, a three-dimensional model of the desired dental object 100 is first created in a CAD program and divided into digital layers (slices), each representing a thin horizontal cross-section of the dental object 100.

[0027] Software in a manufacturing system 200, such as a 3D jet printer, prepares data and controls the print head 201, platform 211, support material 105, and manufacturing material 103. The 3D jet printer may be, for example, an inkjet or MJ printer.

[0028] A fabrication material 103, such as a ceramic slurry, is used to build the dental object 100. A support material 105, such as wax, is used to build a support structure 107 that can support overhangs of the dental object 100. The support material 105 is removed after the printing process.

[0029] Further parameters are determined such as printing speed, layer thickness, material supply, etc. Further process parameters are for example the substrate temperature, the temperature of the support material 105, and the temperature of the drying or evaporation device 209 for removing solvents such as water.

[0030] A green part of the dental object 100 is then created in the manufacturing system 200 by depositing the manufacturing material 103 layer by layer. The green part is the print in its pre-sintered state. The print head 201 moves over the platform 211 and sprays droplets of the manufacturing material 103 and support material 105 onto the surface. The platform 211 can also move underneath the print head 201.

[0031] This process is similar to traditional inkjet printing, where ink droplets are applied to paper or other surface. However, in a three-dimensional jet printing process, this process is repeated in three dimensions with the manufacturing material 103 to spatially manufacture a three-dimensional dental object 100.

[0032] After each layer is applied, both the manufacturing material 103 and the support material 105 are cured or dried. This can be achieved by electromagnetic radiation, heat, airflow with adjustable temperature, humidity, and / or velocity, or chemical reaction, depending on the specific properties of each material. The majority of the drying and solidification is achieved by removing water from the printed dental object 100 during printing. After printing, a certain amount of residual water can still evaporate from the dental object 100, allowing for penetration of the porous structure.

[0033] The manufacturing materials include ceramic oxide particles, a solvent, a dispersant, and / or a precipitating additive. The ceramic oxide particles are, for example, yttrium-stabilized zirconium dioxide. The solvents are, for example, polar and non-polar solvents such as water, alcohols, glycols, and mixtures thereof. The dispersants include, for example, carboxylic acids, amines, or amino alcohols. The precipitating additives are, for example, polysaccharides, cellulose, and derivatives.

[0034] After the printing process and curing is complete, the support material 105 is partially removed, which can be done by temperature, electromagnetic radiation, heated air, water, solvents, or mechanical removal.

[0035] However, when the dental object 100 is printed with the support material 105, a rough surface is formed on the printed dental object 100. This surface roughness is created by the quantization of the printed voxels, or layers. Due to the staircase effect, the spaces between voxels mean that the edges of the printed dental object 100, layer by layer, appear stepped rather than smooth. This creates an uneven, rough surface on the dental object 100.

[0036] This means that the dental object 100 is ground and polished again after the debinding and sintering process to obtain a comfortable oral product for the user. After sintering, the oxide ceramic of the dental object 100 has high strength. However, this makes grinding and / or polishing difficult and time-consuming. Therefore, pre-polishing in the unsintered (green) state is advantageous. Pre-polishing significantly reduces the effort required for final polishing in the dense sintered state.

[0037] For this purpose, a meltable support material 105 is used in this method. When the prefabricated support structure 107 is melted, the support material 105 partially or completely penetrates and is absorbed into the ceramic dental object 100 by capillary action. During infiltration, the porous ceramic of the dental object 100 absorbs the liquid support material 105, filling cavities and increasing density and strength. This is possible because the printed dental object 100 has pore sizes in the nanometer to micrometer range. In this method, the support material 105 is heated after printing and maintained at a temperature above its melting point for a predetermined infiltration time, allowing the liquid support material 105 to penetrate into the printed dental object 100. Capillary forces determine how deeply the liquid support material 105 penetrates into the dental object 100.

[0038] During subsequent cooling of the dental object 100, the supporting material 105 remaining in the dental object 100 solidifies. The solidification of the supporting material 105 within the dental object 100 increases its strength, which would not be present without infiltration. This strength allows the surface of the printed dental object 100 to be pre-polished without generating stresses that could lead to fracture of the dental object 100. The infiltrated dental object 100 has better mechanical strength, which allows for pre-polishing before the sintering process.

[0039] On the other hand, if infiltration is not performed, the printed dental object 100 will have poorer mechanical properties, which may cause parts of the printed dental object 100 to break or crack, rendering the printed dental object 100 unusable or of reduced quality.

[0040] Pre-polishing before the sintering process is more efficient than full polishing afterwards, resulting in time savings in the production of dental object 100. Pre-polishing also reduces the surface roughness of the initial printed state, so that only fine polishing is required in the final sintered state.

[0041] Additionally, additional soluble ion-producing sintering materials, such as dyes or other substances, can be added to the support material 105 so that they are also absorbed during infiltration of the dental object 100. This allows, for example, to form an outer, more translucent layer within the dental object 100 during sintering, or to specifically tailor other properties, such as the color of the dental object 100. This also allows for the subsequent introduction of color gradients into the printed dental object 100.

[0042] This method allows for better and faster handling in the manufacturing process. The use of consumables such as milling cutters and polishing machines is reduced. Finishing time can be reduced by 80%. On the tool side, the service life of diamond milling cutters and polishing machines is extended by a factor of 20.

[0043] 2 shows a further schematic diagram of a manufacturing system 200 for layer-by-layer manufacturing of a dental object 100. The manufacturing system 200 comprises a print head 201 for printing the dental object 100 with a manufacturing material 103 and for printing a support structure 107 with a meltable support material 105 layer-by-layer. In this manufacturing process, a support material 105 that can be liquefied depending on temperature is also printed to manufacture the support structure 107 for the overhang region.

[0044] The melter 203 is used for subsequent melting of the support material 105 of the support structure 107. The melter 203 is configured to maintain the support material 105 at a predetermined temperature for a predetermined soak time. The melter may be, for example, a furnace, heater, or blower.

[0045] Furthermore, the manufacturing system 200 includes a cooling device 205 for cooling the dental object 100. The cooling device 205, for example, hardens the infiltrated support material 105 by cooling, forming a solid matrix within the dental object 100. Regular cooling to room temperature can also be performed without technical assistance.

[0046] To further accelerate the manufacturing process, the manufacturing system may comprise a finishing device 207 for grinding or polishing the dental object 100. This achieves the advantage that all work steps can be performed by the manufacturing system 200. The different devices of the manufacturing system 200 may be integrated into one device or may be spatially separated and located in different locations.

[0047] 3 shows a block diagram of a method for manufacturing a dental object 100. In step S101, the dental object 100 is printed layer-by-layer with a manufacturing material 103, and a support structure 107 is printed layer-by-layer with a meltable support material 105. In step S102, the support material 105 is melted. The previously printed support structure dissolves. In step S103, the melted liquid support material 105 is absorbed or soaked into the manufacturing material 103 of the printed dental object 100.

[0048] After the support material 105 has infiltrated and hardened, the surface of the printed dental object 100 is finished before sintering to achieve the desired surface finish. Finally, in final processing, the finished dental object 100 can undergo further processes such as grinding, polishing, or coating depending on the application requirements to obtain its final shape and surface finish.

[0049] The infiltrated support material 105 forms outer and inner support structures inside the dental object 100. The outer support structures stabilize the geometry or outer geometry and ensure dimensional stability of the dental object 100. The inner support structures increase the strength of the dental object 100 and improve overall handling, even if the outer support structures are removed again.

[0050] All of the features described and shown in connection with the individual embodiments of the invention can be provided in different combinations in the subject matter according to the invention in order to simultaneously realize their advantageous effects.

[0051] All method steps may be performed by apparatus suitable for performing the respective method step. All functions performed by the subject features may be a method step of the method.

[0052] The scope of protection of the invention is given by the claims and is not limited by the features described in the specification or shown in the drawings. [Explanation of symbols]

[0053] 100 Dental Objects 103 Manufacturing materials 105 Supporting materials 107 Support structure 200 Manufacturing System 201 Printhead 203 Melting Equipment 205 Cooling device 207 Finishing Equipment 209 Drying or Evaporation Apparatus 211 Platform

Claims

1. 1. A method for manufacturing a dental object, comprising: - printing the dental object layer by layer with a production material and printing the support structure layer by layer with a meltable support material; - melting the support material; - absorbing the molten support material in the production material of the printed dental object.

2. The method of claim 1 , wherein the material of manufacture comprises an oxide ceramic material.

3. 3. The method of claim 1, wherein the support material comprises a wax and / or a non-ionic surfactant.

4. 10. The method of claim 1, wherein after melting, the support material is maintained at a predetermined temperature for a predetermined soak time.

5. 10. The method of claim 1, wherein the dental object is cooled or the temperature of the dental object is reduced after infiltration of the supporting material.

6. 10. The method of claim 1, wherein the dental object is ground or polished after infiltration with the supporting material.

7. 2. The method of claim 1, wherein after printing the layer, the manufacturing material and / or the support material is cured and / or dried.

8. 8. The method according to claim 7, wherein the curing and / or drying of the manufacturing material and the support material is carried out by means of electromagnetic radiation, ultraviolet light, heat, air currents, convection, evaporation and / or chemical reaction.

9. 10. The method of claim 1, wherein the molten support material only partially penetrates the dental object.

10. 10. The method of claim 1, wherein the support material comprises a doping material that changes the properties of the dental object during sintering or the support material comprises a glass or glaze material.

11. 10. The method of claim 1, wherein the dental object is a crown, a bridge, an abutment, a veneer, an inlay, an onlay, a tabletop, a partial or a complete prosthesis.

12. 1. A manufacturing system for layer-by-layer manufacturing of dental objects, comprising: - a printhead for printing the dental object layer by layer with the production material and for printing the support structure layer by layer with the meltable support material; a melting device for melting the support material.

13. 13. The manufacturing system of claim 12, wherein the melter is configured to maintain the support material at a predetermined temperature for a predetermined soak time.

14. 14. The manufacturing system of claim 13, wherein the manufacturing system comprises a cooling device for cooling the dental objects.

15. 14. The manufacturing system of claim 12 or 13, wherein the manufacturing system comprises a finishing device for grinding or polishing dental objects.

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