CN111086205A

CN111086205A - Tooth model and three-dimensional printing method and device thereof

Info

Publication number: CN111086205A
Application number: CN201811243492.1A
Authority: CN
Inventors: 侯锋
Original assignee: PRISMLAB CHINA Ltd
Current assignee: PRISMLAB CHINA Ltd
Priority date: 2018-10-24
Filing date: 2018-10-24
Publication date: 2020-05-01

Abstract

The invention relates to a three-dimensional printing method of a tooth model, wherein the tooth model is a shell with a cavity, the shell is provided with a first side wall and a second side wall which are opposite, and the method comprises the following steps: identifying a region in the tooth model, wherein the included angle between the tooth model and the scraping direction of a scraper of the three-dimensional printing equipment is within a preset range; in forming the first and second sidewalls of the region, one or more sets of connections are formed extending from the first sidewall to the second sidewall, each set of connections including one or more connections aligned in a height direction of the dental model from a bottom to a top of the cavity. The three-dimensional printing method adopted by the invention can avoid the scraper from touching the sharp bulge on the side wall of the model, thereby improving the success rate of the tooth model forming.

Description

Tooth model and three-dimensional printing method and device thereof

Technical Field

The invention relates to a three-dimensional printing technology, in particular to a three-dimensional printing method and equipment for a tooth model.

Background

In the field of dental medical devices, it is necessary to make a model of a patient's teeth to assist a doctor in dental treatment or correction. Because the tooth models for each patient are unique, it is well suited to be shaped using three-dimensional printing techniques. The three-dimensional printing technology is characterized in that a computer three-dimensional design model is used as a blueprint, special materials such as metal powder, ceramic powder, plastics, cell tissues and the like are stacked layer by layer and bonded through a software layering dispersion and numerical control forming system in a laser beam mode, a hot melting nozzle mode and the like, and finally, an entity product is manufactured through superposition forming. Different from the traditional manufacturing industry in which the raw materials are shaped and cut in a machining mode such as a die and a turn-milling mode to finally produce finished products, the three-dimensional printing changes a three-dimensional entity into a plurality of two-dimensional planes, and the three-dimensional printing is used for producing the three-dimensional entity by processing the materials and superposing the materials layer by layer, so that the manufacturing complexity is greatly reduced. The digital manufacturing mode can generate various parts with complex shapes directly from computer graphic data without complex process, huge machine tool and much manpower, so that the production and the manufacturing can be extended to a wider production crowd.

At present, the forming mode of the three-dimensional printing technology is still evolving, and the used materials are various. Among various molding methods, the photocuring method is a well-established method. The light curing method is to use the principle that light curing materials are cured after being irradiated by ultraviolet light to perform material accumulation molding, and has the characteristics of high molding precision, good surface smoothness, high material utilization rate and the like.

Photocuring processes print layer by layer from the bottom or top to form the workpiece. In this process, after each layer of material is cured, a squeegee is used to smooth the surface of the layer of material to cure the next layer of material. Usually, the teeth and gums in the tooth model are hollow structures, so that only the shell of the tooth model needs to be cured. The two opposite side walls are shrunk and deformed during the curing process of the shell, so that the upper surface planes of the side walls are inclined to form sharp bulges. When a scraper is used to scrape from one side wall of the housing to the other after curing a layer of material of the housing, the scraper is liable to encounter a sharp projection. At this time, the moving squeegee easily breaks the side wall, thereby damaging the workpiece.

Disclosure of Invention

The invention aims to provide a three-dimensional printing method and equipment for a tooth model, which can improve the success rate of tooth model formation.

The invention adopts a technical scheme to solve the technical problem that the tooth model is a shell with a cavity, wherein the shell is provided with a first side wall and a second side wall which are opposite, and the method comprises the following steps: identifying a region in the tooth model, wherein the included angle between the tooth model and the scraping direction of a scraper of the three-dimensional printing equipment is within a preset range; in forming the first and second side walls of the region, one or more sets of connections are formed extending from the first side wall to the second side wall, each set of connections including one or more connections aligned in a height direction of the tooth model from a bottom to a top of the cavity.

Optionally, the method further comprises printing the shell and the one or more connections layer by layer from a bottom to a top of the dental model.

Optionally, the method described above prints the dental model using a photo-curing three-dimensional printing method.

Optionally, the one or more connections in the above method pass through the cavity.

Optionally, in the above method, the one or more connecting portions are sheet-shaped and parallel to a height direction of the tooth model.

Optionally, when printing the housing and the one or more connecting portions, each layer of each connecting portion is linear.

Optionally, the predetermined range in the above method is 80 ° to 100 °.

Optionally, before forming one or more sets of connections extending from the first sidewall to the second sidewall, further comprising: dividing a digital tooth model corresponding to the tooth model into a plurality of layers; identifying the region of each of the plurality of layers.

The technical solution adopted by the present invention to solve the above technical problem may also be a three-dimensional printing apparatus, adapted to print a tooth model, the tooth model being a housing having a cavity, wherein the housing has a first side wall and a second side wall opposite to each other, the three-dimensional printing apparatus including a printing mechanism and a controller, the controller being configured to control the printing mechanism to perform the above method.

The present invention, which has been made to solve the above-mentioned problems, may also be a dental model which is a shell having a cavity, wherein the shell of the dental model has a first side wall and a second side wall opposite to each other, characterized in that the dental model has one or more sets of connecting parts extending from the first side wall to the second side wall in a predetermined area, each set of connecting parts including one or more connecting parts arranged from the bottom to the top of the cavity in a height direction of the dental model.

Optionally, the one or more connections pass through the cavity.

Optionally, the connecting portion is sheet-shaped and parallel to a height direction of the teeth.

The present invention may also provide a method of providing a digital dental model, including providing a digital dental model, the digital dental model being a shell having a cavity, wherein the shell has first and second opposing sidewalls, the dental model having one or more sets of connecting portions extending from the first sidewall to the second sidewall, each set of connecting portions including one or more connecting portions arranged from a bottom to a top of the cavity in a height direction of the dental model.

The three-dimensional printing method and the three-dimensional printing equipment for the tooth model can ensure that the side wall part of the tooth model is not easy to deform to form the sharp bulge, thereby avoiding the damage of a model workpiece caused by the fact that the scraper touches the sharp bulge when contacting the side wall of the model, and improving the success rate of the tooth model forming.

Drawings

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below, wherein:

fig. 1 shows a basic structure of a photo-curing type three-dimensional printing apparatus according to an embodiment of the present invention.

FIG. 2 is a top view of a tooth model.

Fig. 3 is a bottom view of the dental model shown in fig. 2.

FIG. 4 is an enlarged partial schematic view of the first and second sidewall fault planes of the tooth shell as the tooth model is printed to layer B.

Fig. 5 is a schematic view of an exemplary internal structure of a tooth model according to a first embodiment of the present invention.

Fig. 6 is a sectional view of the dental model of the embodiment of fig. 5 taken along a line a-a of a connection portion.

Fig. 7 is a schematic view of an exemplary internal structure of a tooth model according to a second embodiment of the present invention.

Fig. 8A is a schematic view of an exemplary internal structure of a tooth model according to a third embodiment of the present invention.

Fig. 8B is a variation of the third embodiment shown in fig. 8A.

Fig. 9 is a flowchart illustrating a method for photo-curing three-dimensional printing of a dental model according to an embodiment of the present invention.

Fig. 10A-10C are schematic diagrams illustrating a photo-curing type three-dimensional printing process according to an embodiment of the invention.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those specifically described herein, and thus the present invention is not limited to the specific embodiments disclosed below.

As used in this application and the appended claims, the terms "a," "an," and/or "the" are not intended to be inclusive in the singular, but rather are intended to be inclusive in the plural unless the context clearly dictates otherwise. In general, the terms "comprises" and "comprising" merely indicate that steps and elements are included which are explicitly identified, that the steps and elements do not form an exclusive list, and that a method or apparatus may include other steps or elements.

It will be understood that when an element is referred to as being "on," "connected to," "coupled to" or "contacting" another element, it can be directly on, connected or coupled to, or contacting the other element or intervening elements may be present. In contrast, when an element is referred to as being "directly on," "directly connected to," "directly coupled to" or "directly contacting" another element, there are no intervening elements present. Similarly, when a first component is said to be "in electrical contact with" or "electrically coupled to" a second component, there is an electrical path between the first component and the second component that allows current to flow. The electrical path may include capacitors, coupled inductors, and/or other components that allow current to flow even without direct contact between the conductive components.

Fig. 1 illustrates a basic structure of a photo-curing type three-dimensional (3D) printing apparatus according to an embodiment of the present invention. This 3D printing apparatus 100 includes a material tank 110 for containing a light curing resin, an image exposure system 120 for curing the light curing resin, and an elevating table 130 for attaching a molded workpiece. The elevating table 130 is movable up and down in a vertical direction. The image exposure system 120 is located above the material tank 110, and irradiates a beam image to cure a layer of the light-curable resin on the liquid surface of the material tank 110. After the image exposure system 120 irradiates a beam image each time to cure a layer of light-cured resin, the lifting platform 130 drives the formed layer of light-cured resin to slightly descend, and the light-cured resin is uniformly spread on the top surface of the cured workpiece through the scraper 131 to wait for the next irradiation. The squeegee 131 is movable in the horizontal direction. And circulating the steps, and obtaining the three-dimensional workpiece formed by layer-by-layer accumulation.

The image exposure system 120 may irradiate a beam image onto the photocurable resin to form a desired exposure pattern. The image exposure system 120 may use various known techniques capable of forming a beam image.

For example, in one embodiment, the image exposure system 120 may use Digital Light Processing (DLP) projection technology. DLP projection imaging is implemented using a Digital Micromirror Device (DMD) to control the reflection of light. The digital micromirror device can be considered as a mirror. This mirror is composed of hundreds of thousands or even millions of micromirrors. Each micromirror represents a pixel from which an image is constructed.

In another embodiment, the image exposure system 120 may also use Liquid Crystal (LCD) projection technology. The liquid crystal panel comprises a plurality of pixels, each pixel can independently control the polarization direction of polarized light, and the polarized light filters on two sides of the liquid crystal panel are matched to control whether light rays of a certain pixel pass or not, so that light beams passing through the liquid crystal panel system are imaged.

The light curing type 3D printing apparatus 100 inputs a three-dimensional data model of a printing object and decomposes the three-dimensional data model into a plurality of two-dimensional images. Each two-dimensional image represents a layer of the print object. The photocurable 3D printing apparatus 100 sends these two-dimensional images to the image exposure system 120, which projects the two-dimensional images.

In an embodiment of the present invention, the photo-curing type 3D printing apparatus 100 shown in fig. 1 may be used to print the dental model 200. Typically, the dental model 200 includes two portions, upper and lower teeth, and for the following teeth as an example, a top view of the dental model 200 is shown in FIG. 2. Referring to fig. 2, a healthy lower row of teeth is U-shaped, including a front-most incisor area 210, a cuspid area 211 beside the incisor area 210, and the remaining molar area 212. Typically, the lower teeth of a healthy adult include four incisors, two cuspids, and ten molars. Incisors, which are incisors, are used to cut food as the name suggests, and thus, incisors are generally in the shape of a sheet, have a slightly thick root and are thinner toward the top.

Fig. 3 is a bottom view of the dental model 200 corresponding to fig. 2. Referring to FIG. 3, the bottom of the dental model 200 is a cavity 220, and thus has two sidewalls, including a first sidewall 230 at the inner bottom circle of the dental model 200 and a second sidewall 240 at the outer bottom circle of the dental model 200. When printing the dental model 200 using the photo-curing 3D printing apparatus 100 as shown in fig. 1, the dental model 200 is typically printed from the bottom to the top layer by layer. After each layer of material is cured, the 3D printing apparatus 100 may use a squeegee 131 to squeegee the layer of material in direction D.

Fig. 4 is a partially enlarged schematic view of the first 230 and second 240 side wall fault planes of the tooth shell when the tooth model is printed to layer B. Referring to fig. 4, when the tooth model is printed layer by layer from the bottom to the top, some

sharp protrusions

231, 241 may be formed on the cross-sectional surface of the printed first and

second sidewalls

230, 240 due to shrinkage deformation of the material. When the scraper 131 scrapes the bottom of the incisor area 210 located at the front end of the dental model 200, it first scrapes the first sidewall 230 and then the second sidewall 240 in a nearly vertical direction, which easily touches the

sharp protrusions

231, 241 on the sidewalls. When the scraper 131 shown in fig. 1 passes through the

protrusions

231, 241 in the direction D, a certain resistance is applied to the movement of the scraper 131, and in the serious case, the shell of the dental model 200 is damaged.

Fig. 5 is a schematic view of an exemplary internal structure of a dental model according to a first embodiment of the present invention, which is viewed from the same bottom as fig. 3. Referring to fig. 5, the shell in the incisor area 210 of the dental model 200 has a first sidewall 230 and a second sidewall 240 with a connection 250 between the first sidewall 230 and the second sidewall 240. The connecting portion 250 extends from the first side wall 230 to the second side wall 240 along a direction parallel to the direction D of the scraper 131 (see fig. 1), and plays a role of supporting the first side wall 230 and the second side wall 240, so that the first side wall 230 and the second side wall 240 are not easily deformed during 3D printing and curing, and thus are not easily subjected to sharp protrusions. Even if the first and

second sidewalls

230 and 240 are deformed slightly to generate a small protrusion, the connecting portion 250 allows the scraper 131 to pass through the first and

second sidewalls

230 and 240 smoothly through the connecting portion 250 during the forward movement without causing damage to the workpiece due to the protrusion.

Fig. 6 is a sectional view taken along a-a of the connection part 250 in the embodiment shown in fig. 5. Referring to fig. 6, the connection part 250 extends from the bottom to the top of the cavity 220 in the height direction of the dental model 200, and the shape of the connection part 250 is adapted to the shape of the cavity in which it is located. Referring to fig. 5 and 6, the connecting portion 250 is thin and has a thickness of, for example, 0.3-0.5 mm.

It is understood that fig. 5 and 6 are only schematic views and do not represent the actual thickness of the connection part 250. In other embodiments, the thickness of the connection portion 250 may be different. The direction in which the connecting portion 250 extends from the first side wall 230 to the second side wall 240 may not be completely parallel to the direction D of the blade 131, but may have a deviation of, for example, ± 10 °.

Fig. 7 is a schematic view of an exemplary internal structure of a tooth model according to a second embodiment of the present invention. Referring to fig. 7, in this embodiment, there are three sets of connections 250, three sets as shown in fig. 7, between the first and

second sidewalls

230 and 240 of the incisor region 210 of the tooth model 200. The plurality of sets of connection parts 250 are similar in structure and shape to the connection parts 250 shown in fig. 5 and 6. The sets of connections 250 are all located within incisor area 210.

The multiple sets of connecting portions 250 may allow the scraper 131 to pass more smoothly through the front end of the dental model 200 and better support the first and

second sidewalls

230, 240 than a single set of connecting portions 250.

Fig. 8A is a schematic view of an exemplary internal structure of a tooth model according to a third embodiment of the present invention, which is viewed from the same perspective as fig. 6 and is a sectional view taken along a line a-a of the connecting portion 250. Referring to fig. 8A, the connecting portion 250 may be a group of connecting portions, which have a ladder shape and are composed of a plurality of first connecting portions 251 in the shape of wires or strips. The first connection portions 251 are respectively connected between the first and

second sidewalls

230 and 240 at regular intervals in the height direction of the tooth model. Similarly, the plurality of connection portions 250 shown in fig. 7 may also be a plurality of sets of connection portions. Each set of the connecting portions includes a plurality of first connecting portions 251 arranged in the height direction of the tooth model as shown in fig. 8A.

During 3D printing of the dental model 200, the embodiment shown in fig. 8A may help the squeegee 131 to smoothly pass through the first and

second sidewalls

230 and 240 when printing to several layers having the first connection 251. Moreover, due to the supporting function of the first connecting portion 251, the first side wall 230 and the second side wall 240 are not easy to deform, so that the generation of a protrusion at the fault of the first side wall 230 and the second side wall 240 is avoided, and the problem of sharp protrusion is not encountered when the scraper 131 is carried out to the layer without the first connecting portion 251. Furthermore, the present embodiment saves the material and printing time required for 3D printing, compared to the embodiment shown in fig. 6.

Fig. 8B is a variation of the third embodiment shown in fig. 8A. Referring to fig. 8B, the set of connection parts 250 has a plurality of second connection parts 252 having an irregular sheet shape. The second connection portions 252 have a certain interval therebetween. Each second connection portion 252 has a shape corresponding to a cavity between the first sidewall 230 and the second sidewall 240. Thus, the embodiment shown in fig. 8B can help the scraper 131 smoothly pass through the front end of the dental model 200 at multiple levels during 3D printing. Also, the material and printing time required for 3D printing is saved with respect to the embodiment shown in fig. 6.

In addition, the direction D of the example squeegee hanging in fig. 3 and 4 is substantially perpendicular to the incisor area 210 of the tooth model 200, and the angle between the direction D and the first and

second sidewalls

230 and 240 at the bottom of the incisor area 210 may be between 70-90 °. In other embodiments, the direction of squeegee scraping D can vary. For example, the direction of scraping D' is at a greater angle to the first and

second sidewalls

230 and 240 at the bottom of incisor region 210. At this time, the position where the sidewall is easily deformed may be changed, for example, moved to the cuspid region 211, and the region where the connection part 250 is formed may be changed to the cuspid region 211 accordingly. For example, the direction of scraping E may be parallel to the incisor region 210 and substantially perpendicular to the molar region 212. The location where the sidewall deformation is likely to occur at this time may be in the molar region 212, and the region where the connection part 250 is formed may be changed to the molar region 212 accordingly.

Fig. 9 is a flowchart illustrating a method for photo-curing three-dimensional printing of a dental model according to an embodiment of the present invention. The printing method comprises the following steps:

step 901: a three-dimensional data model of the tooth model is obtained.

The tooth model obtained in step 901 is a normal tooth model with a cavity shell, and there is no data about the connection part 250 in the incisor area 210 of the tooth model.

Step 902: the three-dimensional data model is divided into layers.

Step 903: and identifying a preset area in each layer, wherein the included angle of the preset area with the scraping direction of the scraper of the three-dimensional printing equipment is within a preset range.

The identification of the region (e.g., incisor region 210) at step 903 is to determine the location range of the connecting portion 250 to facilitate formation of the connecting portion 250 in the region during subsequent printing. Here, the predetermined range may be between 80 ° and 100 °, and more preferably may be between 85 ° and 90 °.

Step 904: each layer is printed layer by layer.

In the layer-by-layer printing process, when the layer to be printed has the aforementioned predetermined region (e.g., incisor region 210), the controller of the printer controls the printing mechanism to form one or more connections 250 extending from the first sidewall 230 to the second sidewall 240 when forming the first sidewall 230 and the second sidewall 240. The connection portion 250 may adopt several embodiments described above, and a user or a controller specifically sets which embodiment is adopted.

In another embodiment, the tooth model 200 obtained in step 901 may be a digital tooth model. The digital dental model is a shell having a cavity with opposing first 230 and second 240 sidewalls, the digital dental model having the connection portion 250 of the previous embodiment in a predetermined area. The digital dental model may be stored in a server and may be downloaded to a 3D printing device as shown in fig. 1 for printing. In the three-dimensional printing method of this embodiment, since the digital dental model already contains data about the connection portion 250, step 903 can be omitted, and the printer only needs to print according to the digital dental model during the layer-by-layer printing process without actively adding a connection portion.

FIGS. 10A-10C are schematic diagrams illustrating a photo-curing three-dimensional printing process according to an embodiment of the present invention, which is exemplified by the dental model shown in FIG. 6. Referring to fig. 10A, the entire printing process is performed from the very bottom of the dental model, layer by layer, and up. As shown in the left diagram of fig. 10A, it is assumed that the tooth model forms a connection part 250 between the first side wall 230 and the second side wall 240 from the L1 th layer. When printing to the L1 th layer of the tooth model, a layer of connection 250 begins to form between the first sidewall 230 and the second sidewall 240 of the incisor region 210 of the tooth model. As shown in the right drawing of fig. 10A, the tooth model has been printed from the bottom up to the model at level L1 (shown as diagonal portions), including a portion of the first sidewall 230, a portion of the second sidewall 240, and a layer of the linear connecting portion 250.

Referring to the left drawing of fig. 10B, when printing proceeds to the L2 th layer of the tooth model, as shown in the right drawing of fig. 10B, the tooth model has been printed from the bottom until the model of the L2 th layer, including part of the first side wall 230, part of the second side wall 240, and part of the connecting portion 250 (as indicated by the diagonal line portions). It will be appreciated that in the actual resulting model, the first and

second sidewalls

230, 240 and the connecting portion 250 of these portions are integral.

Referring to the left image of fig. 10C, when printing proceeds to the L3 th level of the dental model, it has been printed on top of the connection 250. As shown in the right view of fig. 10C, the tooth model has been printed from the bottom until the model at level L3, including a portion of the first sidewall 230, a portion of the second sidewall 240, and the entire connecting portion 250 (as indicated by the diagonal portions). It will be appreciated that in the actual resulting model, the first and

second sidewalls

230, 240 and the connecting portion 250 of these portions are integral.

It is to be understood that the above description of layer-by-layer printing according to fig. 10A-10C is an example of the embodiment shown in fig. 6. The printing process of the embodiment shown in fig. 8A and 8B is also applicable to the above-described printing process.

In the embodiment of the dental model, the one or more connecting portions 250 preferably have a thickness of 0.3 to 0.5mm in the tooth width direction (direction a in fig. 5) regardless of the shape of the one or more connecting portions, such as a line, a strip, or a sheet.

The invention also includes a three-dimensional printing apparatus for performing the above steps, the printing apparatus comprising a printing mechanism and a controller. The controller is configured to control the printing mechanism to perform the stereolithographic method of printing the dental model shown in fig. 9.

Having thus described the basic concept, it will be apparent to those skilled in the art that the foregoing disclosure is by way of example only, and is not intended to limit the present application. Various modifications, improvements and adaptations to the present application may occur to those skilled in the art, although not explicitly described herein. Such modifications, improvements and adaptations are proposed in the present application and thus fall within the spirit and scope of the exemplary embodiments of the present application.

Also, this application uses specific language to describe embodiments of the application. Reference throughout this specification to "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic described in connection with at least one embodiment of the present application is included in at least one embodiment of the present application. Therefore, it is emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, some features, structures, or characteristics of one or more embodiments of the present application may be combined as appropriate.

Aspects of the methods and systems of the present application may be performed entirely by hardware, entirely by software (including firmware, resident software, micro-code, etc.), or by a combination of hardware and software. The above hardware or software may be referred to as "data block," module, "" engine, "" unit, "" component, "or" system. The processor may be one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), digital signal processing devices (DAPDs), Programmable Logic Devices (PLDs), Field Programmable Gate Arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, or a combination thereof. Furthermore, aspects of the present application may be represented as a computer product, including computer readable program code, embodied in one or more computer readable media. For example, computer-readable media can include but are not limited to magnetic storage devices (e.g., hard disk, floppy disk, magnetic strips … …), optical disks (e.g., Compact Disk (CD), Digital Versatile Disk (DVD) … …), smart cards, and flash memory devices (e.g., card, stick, key drive … …).

A computer readable signal medium may comprise a propagated data signal with computer program code embodied therein, for example, on a baseband or as part of a carrier wave. The propagated signal may take any of a variety of forms, including electromagnetic, optical, and the like, or any suitable combination. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. Program code on a computer readable signal medium may be propagated over any suitable medium, including radio, electrical cable, fiber optic cable, radio frequency signals, or the like, or any combination of the preceding.

Additionally, the order in which elements and sequences of the processes described herein are processed, the use of alphanumeric characters, or the use of other designations, is not intended to limit the order of the processes and methods described herein, unless explicitly claimed. While various presently contemplated embodiments of the invention have been discussed in the foregoing disclosure by way of example, it is to be understood that such detail is solely for that purpose and that the appended claims are not limited to the disclosed embodiments, but, on the contrary, are intended to cover all modifications and equivalent arrangements that are within the spirit and scope of the embodiments herein. For example, although the system components described above may be implemented by hardware devices, they may also be implemented by software-only solutions, such as installing the described system on an existing server or mobile device.

Similarly, it should be noted that in the preceding description of embodiments of the application, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure aiding in the understanding of one or more of the embodiments. This method of disclosure, however, is not intended to require more features than are expressly recited in the claims. Indeed, the embodiments may be characterized as having less than all of the features of a single embodiment disclosed above.

Numerals describing the number of components, attributes, etc. are used in some embodiments, it being understood that such numerals used in the description of the embodiments are modified in some instances by the use of the modifier "about", "approximately" or "substantially". Unless otherwise indicated, "about", "approximately" or "substantially" indicates that the number allows a variation of ± 20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximations that may vary depending upon the desired properties of the individual embodiments. In some embodiments, the numerical parameter should take into account the specified significant digits and employ a general digit preserving approach. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the range are approximations, in the specific examples, such numerical values are set forth as precisely as possible within the scope of the application.

Although the present invention has been described with reference to the present specific embodiments, it will be appreciated by those skilled in the art that the above embodiments are merely illustrative of the present invention, and various equivalent changes and substitutions may be made without departing from the spirit of the invention, and therefore, it is intended that all changes and modifications to the above embodiments within the spirit and scope of the present invention be covered by the appended claims.

Claims

1. A method of three-dimensional printing of a dental model, the dental model being a shell having a cavity, wherein the shell has first and second opposing sidewalls, the method comprising:

identifying a region in the tooth model, wherein the included angle between the tooth model and the scraping direction of a scraper of the three-dimensional printing equipment is within a preset range;

in forming the first and second side walls of the region, one or more sets of connections are formed extending from the first side wall to the second side wall, each set of connections including one or more connections aligned in a height direction of the tooth model from a bottom to a top of the cavity.

2. The method of claim 1, wherein the shell and the one or more connections are printed layer by layer from a bottom to a top of the tooth model.

3. The method of claim 1 or 2, wherein the dental model is printed using a stereolithography method.

4. The method of claim 1, wherein the one or more connections pass through the cavity.

5. The method of claim 1, wherein the one or more connectors are sheet-like and parallel to a height direction of the tooth model.

6. The method of claim 2, wherein each layer of each of the connections is linear when printing the housing and the one or more connections.

7. The method of claim 1, wherein the predetermined range is 80 ° -100 °.

8. The method of claim 1, further comprising, prior to forming one or more sets of connections extending from the first sidewall to the second sidewall:

dividing a digital tooth model corresponding to the tooth model into a plurality of layers;

identifying the region of each of the plurality of layers.

9. A three-dimensional printing apparatus adapted to print a dental model, the dental model being a shell having a cavity, wherein the shell has first and second opposing sidewalls, the three-dimensional printing apparatus comprising a printing mechanism and a controller configured to control the printing mechanism to perform the method of any one of claims 1-8.

10. A dental model being a shell having a cavity, wherein the dental model has opposite first and second side walls in the shell, characterized in that the dental model has one or more sets of connections in predetermined areas extending from the first to the second side wall, each set comprising one or more connections arranged from the bottom to the top of the cavity in the height direction of the dental model.

11. The dental model of claim 10, wherein the one or more connectors pass through the cavity.

12. The dental model of claim 10, wherein the connecting portion is plate-shaped and parallel to a height direction of the teeth.

13. A method of providing a digital dental model comprising providing a digital dental model that is a shell having a cavity, wherein the shell has opposing first and second sidewalls, the dental model having one or more sets of connections extending from the first to second sidewalls, each set of connections comprising one or more connections arranged from a bottom to a top of the cavity in a height direction of the dental model.