WO2024083859A1

WO2024083859A1 - Applicator device and method for operating an applicator device

Info

Publication number: WO2024083859A1
Application number: PCT/EP2023/078878
Authority: WO
Original assignee: Bredent Gmbh & Co. Kg
Priority date: 2022-10-17
Filing date: 2023-10-17
Publication date: 2024-04-25
Also published as: DE102023128465A1

Abstract

The invention relates to an applicator device and a method for operating an applicator device, which comprises a measuring system for detecting a surface of an object to be coated and which uses a multi-axis movement guide to apply a plurality of liquids for printing the object to be coated in a multi-part printing system, such that surfaces or surface regions are coated with the liquid(s) in such a way that the physical properties of the dental prosthesis change.

Description

APPLICATION DEVICE AND METHOD FOR OPERATING A

APPLICATION DEVICE

The invention relates to an application device and a method for operating an application device.

Digital tools are increasingly being used to produce dentures, which have significantly reduced processing times compared to conventional manufacturing and enable cost-effective production.

DE 10 2010 037 160 A1 discloses a method for producing dental prostheses, in which several layers of a material mixture are applied to a support structure in order to produce a veneer, depending on a digital model of the dental prosthesis. Certain layers of the layers applied immediately one after the other can also be colored. A holder is provided for aligning or positioning the support, which is positioned depending on control commands.

US 2010/0260924 A1 describes a digital printing process that is used to functionalize the surface of dental prostheses. This procedure produces a multi-colored surface that matches the color of the original teeth.

WO 2018/050811 A1 describes a device for functionalization for dental applications and a method therefor, wherein the application device comprises a support for receiving a partially processed dental molded body for the production of a dental restoration and a Delivery device for at least partially infiltrating a functionalizing agent onto the surface of the dental molded body.

Based on this prior art, the object now is to provide a further improved application device and a method for operating the application device.

This object is achieved by the independent patent claims. Further advantageous embodiments of the invention are the subject of the subclaims. These can be combined with one another in a technologically meaningful way. The description, particularly in connection with the drawing, additionally characterizes and specifies the invention.

According to the invention, an application device is created in the manufacture of dental prostheses, which comprises a measuring system for detecting a surface of an object to be coated from a dental material and which, by means of a multi-axis movement guide, causes an application of several liquids for printing the object to be coated in a multi-part printing system, so that surfaces or surface areas are coated with the liquid(s) in such a way that the physical properties of the dental prosthesis change.

Dental materials include organic, inorganic and hybrid materials, such as metals, ceramics, plastics, plasters, silicones or hybrid variants of these. The printing system, consisting of several separate individual injectors, can coat different printable objects with different material compositions using liquids adapted for this purpose and different purposes and/or base chemistry. Liquids with different base chemistry can be organic, inorganic, solid-based, solid-free, water-based, alcohol-based or Based on fats, without any risk of contamination of the liquids in the printing system with each other and taking into account the necessary chemically/physically inert storage in a separate print head. The liquids can contain chemical or physical reactions during or after application, e.g. polymerisation by air/heat/light or hardening by these, or simply the application of liquid for a necessary material-specific post-treatment as well as thermal treatment or firing in a kiln. The adjustment or change of the physical properties relates both to the optical appearance, i.e. gloss, colour, opacity, fluorescence, translucency, and to the adjustment of the roughness by means of glazes as a coating to minimise roughness, coating with fired opaques, colours on inorganic frameworks, applications of coatings or liquids to change the hardness of the surface, gloss, wetting behaviour for further subsequent processes, biological properties (biofilm) or change of the adhesive properties of the surface (adhesion promoter or hardener). This also includes a structural adjustment of the shape (change of the former volume before processing, dimensions) by applying suitable coatings to the structure-forming areas.

According to one embodiment of the invention, the measuring system is arranged as an optical or tactile detection of the object to be printed within the printer or is designed to transfer an object already detected externally into a coordinate system of the application device, in particular by means of a zero clamping device.

According to a further embodiment of the invention, the pressure system comprises several separate individual injectors. According to a further embodiment of the invention, the printing system coats partially in such a way that a shaping, structure-producing effect is achieved which has a layer thickness of up to 1.5 mm.

According to a further embodiment of the invention, the printing system comprises a fixed or replaceable mixed material magazine which simultaneously contains different liquids for the application and can be used one after the other without replacing, cleaning or flushing system components.

According to a further embodiment of the invention, a UV light source is arranged for UV polymerization, which fixes the applied liquid during the printing process by UV irradiation.

According to a further embodiment of the invention, a heat source is arranged which dries, hardens or polymerizes the applied liquid.

According to a further embodiment of the invention, the object to be coated is mounted on a support which is provided with a multi-axis motion guide.

According to a further embodiment of the invention, the motion guide is provided with a counterweight in one direction of movement in the gravitational field in order to achieve a movement with reduced expenditure of force.

According to a further embodiment of the invention, the printing system is displaceable along a direction towards the object to be coated. Furthermore, a method for operating an application device as described above is specified, in which a CAD system uses original design data of the object to be printed and a stored surface segmentation, on the basis of which an automatic assignment of the surface to be functionally coated is stored.

In the process, the release of the droplets of the liquids can be dynamically controlled and adapted to the physical/chemical properties and intended use and application of the liquids and printing object.

In addition, individual print templates can be stored for specific liquids, which can be assigned manually or automatically when the liquid is selected.

Some examples of implementation are explained in more detail below using the drawing. They show:

Figure 1 shows schematically an application device in a side view,

Figure 2 a detail of the application device in a side view,

Figure 3 shows another detail of the application device in a side view,

Figure 4 shows a further detail of the application device in a sectional view,

Figure 5A shows a detail of the processing with the application device in a first side view, Figure 5B shows a detail of the processing with the application device in a second side view,

Figure 6A shows a further detail of the processing with the application device in a first side view,

Figure 6B shows a further detail of the processing with the application device in a second side view, and

Figure 7 shows a further detail of the processing with the application device in a side view.

In the figures, identical or functionally equivalent components are provided with the same reference symbols.

Figure 1 shows a schematic side view of an embodiment of an application device 5 according to the invention. The printer or the application device 5 (these terms are used synonymously) comprises a measuring system 10 for detecting a surface 15 of an object 20 to be coated. The object 20 to be coated is arranged on a support 25, which, by means of a multi-axis movement guide 30, applies several liquids for printing on the object 20 to be coated in a multi-part printing system 35, so that surfaces 15 or surface areas are coated with the liquid(s) in such a way that the physical properties of the dental prosthesis change.

The measuring system 10 can be arranged as an optical or tactile detection of the object 20 to be printed within the printer 5. Alternatively, an object already detected externally can also be integrated into a coordinate system of the Application device 5, in particular by means of a zero clamping device.

As shown in Figure 2, the pressure system 35 can comprise a plurality of separate individual injectors 40, 40'. The pressure system 35 comprises a fixed or replaceable mixed material magazine 45 which simultaneously contains different liquids for the application, which can be applied one after the other without replacing, cleaning or flushing system components.

Furthermore, a UV light source (not shown in Figure 1 or Figure 2) can be arranged for UV polymerization, which fixes the applied liquid during the printing process by means of UV irradiation. Alternatively or additionally, a heat source (not shown in Figure 1 or Figure 2) can be arranged, which dries, hardens or polymerizes the applied liquid.

The release of the droplets of the liquids can be dynamically controlled and can be adapted to the physical/chemical properties and intended use and application of the liquids and the printed object. The dynamic control of the droplets 55 of the liquids can be carried out by means of a light source 60 and a camera 65 on the individual injector 40, which can detect the release of the droplets 55 and process them electronically, as shown in Figure 1 and Figure 2.

The multi-axis motion guide 30 is shown in more detail in Figure 3. The object 20 to be coated is arranged on the support 25, which can be pivoted or moved around four axes in order to reach the desired location on the object 20 to be coated with the pressure system 35 or to be able to detect the object 20 with the measuring system 10. The motion guide 30 comprises an arm 70, at the end of which the support 25 is located. The support 25 can be rotated about a vertical axis of rotation 75. The arm 70 can be rotated about a horizontal pivot axis 80. The motion guide 30 is designed in such a way that, in addition, independent displacements in a vertical direction 85 and in a horizontal direction 90 aligned perpendicular to the axis of rotation 75 and the pivot axis 80 are possible. The mobility about four axes allows precise scanning of the object 20 with the measuring system. Furthermore, the printing system 35 can be displaced in a displacement direction 95 parallel to the pivot axis 80, so that the printing system 35 is aligned above the object 20 attached to the support 25. In this way, a stable guidance of the printing system 35 is achieved. Together with the four-axis control of the motion guide 30, this results in a five-axis operation of the application device 5 according to the invention.

The movement of the motion guide 30 along the vertical direction 85 usually takes place in the gravitational field in the direction of the weight of the complete structure of the movable parts of the motion guide 30 together with the object 20 to be processed. How this movement can also be carried out with less effort is described below with reference to Figure 4 in a further embodiment of the application device 5 according to the invention.

Figure 4 shows a sectional view through the application device 5 in the area of the movement guide 30. It can be seen that the part of the movement guide 30 consisting of the support 25 and the arm 70 is separated from the other components by a partition 100. Behind the partition 100 there is an electric motor 105 which drives a toothed belt 110 which is connected to the arm 70 at its first end. In this way, a movement along the vertical direction 85 can be achieved. The second end of the toothed belt 110 is connected to a counterweight 115 which is connected to the Motion guide 30 is adapted so that a movement along the vertical direction 85 can be carried out with reduced effort. In this way, a less powerful electric motor 105 can be used, which enables a more compact design. Furthermore, a linear guide 120 can be seen in Figure 4, which enables the movement along the horizontal direction 90. The movement around the rotation axis 75 and the pivot axis 80 is also made possible by means of electric motors that are not explicitly shown in the figures.

When operating the application device 5, a CAD system, which is implemented, for example, on the computer 50 shown in Figure 1, can use a stored surface or volume segmentation using original design data of the object 20 to be printed, on the basis of which an automatic assignment of the surface 15 to be functionally coated or of three-dimensional components is stored.

Individual printing templates are stored for the specific liquids, which can be assigned manually or automatically when the liquid is selected. The printing system 35 can partially coat in such a way that a shaping, structure-generating effect is achieved with a layer thickness of up to 1.5 mm.

Surface coating, creating a texture or using color printing affect individual anatomical areas in the manufacture of dental prostheses. In general, such areas are offered or taken into account in CAD design for the non-manufacturing of dental prostheses, as they are very detailed, individual and also polychromatic. The individual polychromatic additive surface structuring or coating is not available in a CAD/CAM implementation. In the inventive approach, it is now possible to manufacture CAD/CAM dental prostheses in using a suitable machining process, either individually or using surface shape libraries.

The first step involves an optical recording of the dental prosthesis produced using CAD/CAM or manually. The second step involves a CAD design of a monochromatic or polychromatic surface. This 3D surface structure is then printed polychromatically or monochromatically. It is also possible to use surface coatings that change the physical properties of the dental prosthesis, such as opacity, fluorescence or roughness, but also biological or chemical properties.

In general, the process is as follows. The dental prosthesis to be optically recorded is placed on the movable support 25. The measuring system 10 records the surface 15 of the object 20 during the movement control 30 of the multi-axis system. The optical recording of the object is processed in the computer 50 using software and is available to the CAD software for further manipulation of the surfaces. Using the CAD software, the digitally generated structures/textures are placed digitally on the surfaces in the CAD. This is done with the help of shape or surface libraries, or by using CAD tools that generate these individually.

In addition to the digital generation of 3D surfaces or shape-giving textures for coating them, it is also possible to add color to the captured surfaces separately or to provide them with a functional coating. The process here is identical to that described above. To define the color areas, you can use prefabricated or customizable color/shape libraries, or you can individually determine them using CAD design tools. The printing process is as follows. After CAD processing, the data for print preparation is processed in the CAM. Here, the printing strategy (movement sequence, order, pressure, color range, angle of attack, material allocation) is defined in the allocation of different materials, their printing properties, viscosity or wettability, application angle, printing speed or material quantity.

The individual droplets 55 are released by the individual injector 40 and pass through a measuring field of the camera system 65 in their trajectory, which measures the size of the droplets. This enables dynamic control of the release quantity in relation to the calculated saturation of, for example, a porous material and thus coloring or physical adaptation.

However, the calculated material requirement or order for the physical generation of surface coatings or three-dimensional shaping textures can also be achieved.

Figures 5A and 5B show a structuring coating (black arrows 125) using the example of gums, and Figures 6A and 6B show teeth. Here, separable, shape-adaptable surface areas can be applied three-dimensionally in order to structure or contour the existing surface with hard or soft tooth parts of the denture to match the shape.

In Figures 5A and 5B this concerns the gingiva, avoel processes, labial frenulum, mucous membrane folds, raphe palatinum, papilla incisiva, or similar.

In Figures 6A and 6B, a three-dimensional structure is printed for teeth. This contouring is generally referred to as "texture" and is independent of the material to be printed, which can be ceramic, polymer or hybrid material. It is also possible to make a color adjustment by means of an appropriate color-giving coating on the respective denture, which can be coated with suitable glazes with different optical or physical purposes (matt, high gloss, opaque, transparent, fluorescent...) or used to seal open porosities, as shown in Figure 6B.

Figure 7 shows a surface segmentation or area segmentation or volume segmentation, which is not limited to a two-dimensional description. The area segmentation is shown using three areas A, B and C. The area segmentation includes a digital shape database of dental prostheses, in which a corresponding area to be functionalized is predefined according to the intended purpose of the coating. This digital shape database, or information extracted from it (material, area) of the coating, is suitable for being imported into the CAD or CAM of the printing system in order to be used for further processing of the print. Area segmentation consists of at least one area of the digital shape, area or surface and can be subsequently adapted by the user.

Furthermore, the software and/or the printer can contain elements of AI (artificial intelligence) or process AI-generated data to define areas. AI-based area or shape recognition enables individual assignment of colors or areas that the user does not have to define himself or herself, by adopting and/or adapting the AI's suggestions.

The printer or the application device 5 prints the surface 15 of prostheses using at least two different liquids suitable for the functionalization of organic, inorganic or hybrid Dental prostheses. Functionalization involves the infiltration of porous or partially porous surfaces 15 to change the physical properties of the material to be printed (color, opacity/transparency/firing-sintering behavior, strength, density...) and the surface coating of partially porous/dense surfaces of organic/inorganic/hybrid dental prostheses to change the physical properties of the material to be printed, e.g. surface sealing, reduction of roughness, color, opacity, transparency, firing-sintering behavior, strength, density, wettability, chemical or biological properties of the surface 15 using suitable liquids.

The calibration function using an optical, tactile or other imaging measuring unit is used to capture an object 20 to be processed in the printer, for example using the measuring device 10, in the digital coordinate system of the printer in order to match it with the original CAD data set and to construct the processing of the object in the CAD process on the original CAD data set or parts thereof. The object 20 is captured using the calibration function in order to generate a data set directly by the printer in order to generate the CAD post-processing on it. The calibration function can also be used to transfer a zero-point clamping system from an external measuring or processing system to the coordinate system of the printer.

It is not intended to produce additive material generation in the printer, which would allow a denture or parts of a denture to be completely shaped. Rather, the invention only provides for the creation of superficial layer(s) that physically change the properties of the printed material. Accordingly, the maximum expected layer thickness is less than 3 mm. Another special feature of the printer is that it can print both solid-free and solid-containing inks of different viscosities and chemical compositions. Coloring substances that can be used include dissolved metal salts based on chloride or nitride, acetate, ceramic paints/glazes and photopolymerizable inks. Another version of the printer has a UV light source for polymerizing light-curing liquids.

The features specified above and in the claims as well as those shown in the figures are applicable both individually and in different

Combination can be implemented advantageously. The invention is not limited to the described embodiments, but can be modified in many ways within the scope of expert knowledge.

List of reference symbols:

5 Application device

10 Measuring system

15 Surface

20 Object

25th edition

30 Motion control

35 Printing system

40 Single injector

45 Material magazine

50 computers

55 droplets

60 Light source

65 Camera

70 Arm

75 rotation axis

80 swivel axis

85 Direction

90 direction

95 Shift direction

100 Partition

105 Electric motor

110 Timing belt

115 Counterweight

120 Linear guide

125 arrows

Claims

Expectations:

1 . Application device in the manufacture of dental prostheses, which comprises a measuring system for detecting a surface of an object to be coated and which, by means of a multi-axis movement guide, applies several liquids for printing on the object to be coated in a multi-part printing system, so that surfaces or surface areas are coated with the liquid(s) in such a way that the physical properties of the dental prosthesis change.

2. Application device according to claim 1, in which the measuring system is arranged as an optical or tactile detection of the object to be coated within the printer, or is designed to transfer an object already detected externally into a coordinate system of the application device, in particular by means of a zero clamping device.

3. Application device according to claim 1 or 2, wherein the pressure system comprises several separate individual injectors.

4. Application device according to one of claims 1 to 3, wherein the pressure system comprises a fixed or replaceable mixed material magazine which simultaneously contains different liquids for the application and can be applied one after the other without replacing, cleaning or rinsing system components.

5. Application device according to one of claims 1 to 4, in which a UV light source is arranged for UV polymerization, which fixes the applied liquid during the printing process by the UV irradiation.

6. Application device according to one of claims 1 to 5, in which a heat source is arranged which dries, hardens or polymerizes the applied liquid.

7. Application device according to one of claims 1 to 6, in which the object to be coated is mounted on a support which is provided with a multi-axis movement guide.

8. Application device according to claim 7, wherein the movement guide is provided with a counterweight in a direction of movement in the gravitational field in order to achieve a movement with reduced expenditure of force.

9. Application device according to one of claims 1 to 8, wherein the pressure system is displaceable along a direction towards the object to be coated.

10. Method for operating an application device, in particular according to one of claims 1 to 9, in which a CAD system uses original design data of the object to be printed and a stored surface or volume segmentation, on the basis of which an automatic assignment of the surface to be functionally coated or of three-dimensional components is stored.

11. Method according to claim 10, in which a release of the droplets of the liquids is dynamically controlled and adapts to the physical/chemical properties and intended use and application of the liquids and printing object.

12. Method according to claim 10 or 11, in which individual printing templates are stored for the specific liquids, which can be assigned manually or automatically when selecting the liquid

13. Method according to one of claims 10 to 12, in which the printing system partially coats in such a way that a shaping structure-producing effect is achieved which has a layer thickness of up to 3 mm, preferably up to 1.5 mm.

14. Method according to one of claims 10 to 13, wherein the printing system provides an area segmentation with a digital shape database of dental prostheses, in which a corresponding area to be functionalized is predefined according to the intended purpose of the coating.

15. Method according to one of claims 10 to 14, in which the printing system enables area or shape recognition on the surface of the object to be processed, which works with AI-based software.