WO2021147336A1

WO2021147336A1 - Method for fabricating shell-shaped dental instrument

Info

Publication number: WO2021147336A1
Application number: PCT/CN2020/113793
Authority: WO
Inventors: 曾鹏
Original assignee: 上海阔鸿信息科技有限公司
Priority date: 2020-01-20
Filing date: 2020-09-07
Publication date: 2021-07-29
Also published as: CN113134974A

Abstract

A method for fabricating a shell-shaped dental instrument, comprising: obtaining a three-dimensional digital model of a shell-shaped dental instrument (101); inspecting the three-dimensional digital model of the shell-shaped dental instrument (103); according to the result of inspection, directly modifying the three-dimensional digital model of the shell-shaped dental instrument (105); and using 3D printing technology to make the shell-shaped dental instrument on the basis of the modified three-dimensional digital model of the shell-shaped dental instrument (107). The present method can overcome the limitations on various aspects of a shell-shaped dental instrument caused by the limitedness of the traditional hot pressing film forming process.

Description

Manufacturing method of shell-shaped dental instruments

Technical field

The present application generally relates to a method for manufacturing a shell-shaped dental instrument, especially a method for manufacturing a shell-shaped dental instrument based on 3D printing technology.

Background technique

Due to the advantages of aesthetics, convenience, and ease of cleaning, shell-shaped dental instruments based on polymer materials (for example, shell-shaped appliances, shell-shaped retainers, etc.) are becoming more and more popular.

The traditional manufacturing method of shell-shaped dental instruments is based on the hot pressing film forming process. However, the limitations of the process itself have caused limitations in all aspects of the shell-shaped dental instruments.

In view of the above, it is necessary to develop a new manufacturing method of shell-shaped dental instruments to get rid of the limitations of traditional techniques on various aspects of shell-shaped dental instruments.

Summary of the invention

One aspect of the present application provides a method for manufacturing a shell-shaped dental instrument, including: obtaining a three-dimensional digital model of the shell-shaped dental instrument; inspecting the three-dimensional digital model of the shell-shaped dental instrument; and directly Modifying the three-dimensional digital model of the shell-shaped dental appliance; and using 3D printing technology to produce the shell-shaped dental appliance based on the modified three-dimensional digital model of the shell-shaped dental appliance.

In some embodiments, the shell-shaped dental appliance may be a shell-shaped appliance for repositioning the teeth from the first layout to the second layout.

In some embodiments, the inspection may be based on finite element analysis.

In some embodiments, the inspection may include at least one of the following: orthodontic force borne by the teeth; anchorage force borne by the teeth; displacement of the teeth; anchorage distribution; and extraction force of the shell-shaped dental instrument.

In some embodiments, the three-dimensional digital model of the shell-shaped dental appliance may be an STL model.

In some embodiments, the manufacturing method of the shell-shaped dental instrument may further include: obtaining a three-dimensional digital model of the tooth; and generating the three-dimensional shell-shaped dental instrument by wrapping the three-dimensional digital model of the tooth. Digital model.

In some embodiments, the modification to the three-dimensional digital model of the shell-shaped dental appliance may be a modification to its outer surface.

In some embodiments, the modification of the three-dimensional digital model of the shell-shaped dental appliance may be to change its local thickness by modifying its outer surface.

In some embodiments, the modification to the outer surface of the three-dimensional digital model of the shell-shaped dental appliance may include at least one of the following: expansion, corrosion, and smoothing.

In some embodiments, modifying the three-dimensional digital model of the shell-shaped dental appliance may include: a computer receives a user instruction; and the computer modifies the three-dimensional digital model of the shell-shaped dental appliance according to the user instruction, Wherein, the user instruction is input by the user based on the inspection result and the three-dimensional digital model of the shell-shaped dental instrument graphically displayed on the user interface of the computer.

Description of the drawings

The above and other features of the content of this application will be more fully understood through the following description and appended claims in combination with the accompanying drawings. It should be understood that these drawings only depict several implementations of the content of this application, and therefore should not be considered as limiting the scope of the content of this application. By adopting the drawings, the content of this application will be explained more clearly and in detail.

Fig. 1 is a schematic flowchart of a method for manufacturing a shell-shaped dental appliance in an embodiment of the application;

Fig. 1A is a schematic flow chart of generating a three-dimensional digital model of a shell-shaped dental instrument based on a three-dimensional digital model of teeth in an embodiment of the application;

Fig. 2A schematically shows the inner surface of a three-dimensional digital model of a shell-shaped dental appliance in an embodiment of the present application;

FIG. 2B schematically shows how the inner surface of the three-dimensional digital model of the shell-shaped dental appliance in an embodiment of the present application wraps the three-dimensional tooth model;

Fig. 3A shows the interface when using Materialise 3-matic software to wrap the three-dimensional digital model of the tooth in an embodiment of the present application;

Fig. 3B shows the interface of the closed surface obtained after wrapping the three-dimensional digital model of the tooth using Materialise 3-matic software in an embodiment of the present application;

Fig. 4 schematically shows a simplified numerical model in an embodiment of the present application; and

Fig. 5 schematically shows the relationship between the force value and the cross-sectional area of the shell-shaped appliance in an embodiment of the present application.

Detailed ways

In the following detailed description, reference is made to the drawings constituting a part thereof. In the drawings, similar symbols usually indicate similar components, unless the context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Without departing from the spirit or scope of the subject matter described herein, other embodiments may be adopted, and other changes may be made. It should be easy to understand that various aspects of the content of the application described generally in this article and illustrated in the accompanying drawings can be configured, replaced, combined, and designed with many different configurations, and all of these are clearly conceived. , And form part of the content of this application.

In order to overcome the limitation of various aspects of shell-shaped dental instruments by the traditional hot-pressing film forming process, the inventors of the present application have developed a method for manufacturing shell-shaped dental instruments based on 3D printing technology after a lot of work.

The shell-shaped dental instrument is an integral shell shape to form a cavity for accommodating the teeth, and the geometry of the cavity is basically matched with the teeth of a specific layout.

In one embodiment, the shell-shaped dental appliance may be a shell-shaped appliance, the geometry of which enables it to reposition the teeth from the first layout to the second layout using the elastic force generated by the deformation. In yet another embodiment, the shell-shaped dental appliance may be a shell-shaped holder for holding the teeth in a desired layout.

Please refer to FIG. 1, which is a schematic flowchart of a method 100 for manufacturing a shell-shaped dental instrument based on 3D printing technology in an embodiment of this application.

In 101, a three-dimensional digital model of a shell-shaped dental instrument is generated based on a three-dimensional digital model of the tooth.

In one embodiment, the three-dimensional digital model of the tooth may be a file in STL (Stereolithography) format. The STL file format is an interface protocol formulated by 3D SYSTEMS in 1988. It is a three-dimensional graphics file format that serves rapid prototyping technology. The STL file is composed of the definitions of multiple triangular faces. The definition of each triangular face includes the three-dimensional coordinates of each vertex of the triangle and the normal vector of the triangular face. The STL model is essentially a three-dimensional body surrounded by a closed surface. The following embodiments will take the STL model as an example for description. Under the enlightenment of this application, it can be understood that, in addition to triangular faces, the three-dimensional digital model of teeth can also be expressed by other polygonal faces, for example, quadrilateral faces.

Please refer to FIG. 1A, which is a schematic flowchart of 101 in an embodiment of this application.

In 1011, a three-dimensional digital model of the tooth is obtained.

In one embodiment, the shell-shaped dental appliance may be a shell-shaped appliance, and the three-dimensional digital model of teeth used to generate the three-dimensional digital model of the shell-shaped dental appliance may be a dentition in a target layout corresponding to an orthodontic step (e.g., maxillary dentition). Or mandibular dentition) three-dimensional digital model. In yet another embodiment, the shell-shaped dental appliance may be a shell-shaped holder, and the three-dimensional digital model of teeth may be a three-dimensional digital model of a dentition in a desired layout (for example, an upper jaw dentition or a lower jaw dentition).

Orthodontic treatment with a shell-shaped appliance usually requires the treatment to be divided into multiple successive treatment steps (for example, 20-40 successive treatment steps), and each treatment step corresponds to a shell-shaped appliance, which is used to treat the teeth. Reposition from the initial layout of the treatment step to the target layout of the treatment step.

In one embodiment, the shell-shaped appliance can be made based on the three-dimensional digital model of the dentition in the target layout corresponding to the treatment step.

In one embodiment, based on the three-dimensional digital model of the dentition under the original layout before the orthodontic treatment, a series of successive correction step target layouts can be generated.

In one embodiment, the patient's jaw can be scanned directly to obtain a three-dimensional digital model of the dentition in the original layout. In another embodiment, a solid model of the patient's jaw, such as a plaster model, can be scanned to obtain a three-dimensional digital model of the dentition in the original layout. In another embodiment, a three-dimensional digital model of the dentition in the original layout can be obtained by scanning the bite mold of the patient's jaw.

In one embodiment, after obtaining the three-dimensional digital model of the dentition in the original layout, it can be segmented so that the teeth in the three-dimensional digital model are independent of each other, so that each tooth can be moved individually.

In one embodiment, a series of successive intermediate layouts may be generated based on the original layout and the desired layout, that is, the target layout of a series of successive correction steps.

In one embodiment, the three-dimensional digital model of the dentition in the desired layout may be obtained based on the segmented three-dimensional digital model of the dentition in the original layout. In one embodiment, the segmented three-dimensional digital model of the dentition under the original layout can be manually operated to move each tooth to a desired position to obtain the three-dimensional digital model of the dentition under the desired layout. In yet another embodiment, a computer may be used to automatically move each tooth to a desired position based on the segmented three-dimensional digital model of the dentition in the original layout to obtain the three-dimensional digital model of the dentition in the desired layout.

In one embodiment, after the original layout and the desired layout are obtained, interpolation calculations can be performed based on the two to obtain a series of successive correction step target layouts.

In another embodiment, the three-dimensional digital model of the dentition under the original layout can be manually operated to directly obtain the target layout of a series of successive correction steps.

In another embodiment, a computer can be used to automatically generate a series of successive correction steps based on the three-dimensional digital model of the dentition in the original layout by using a specific method (for example, a spatial search method).

In 1013, based on the three-dimensional digital model of the teeth, the inner surface of the three-dimensional digital model of the shell-shaped dental instrument is generated.

Please refer to FIG. 2A, which schematically shows the inner surface 200 of the three-dimensional digital model of the shell-shaped dental instrument in an embodiment of the present application. In one embodiment, according to the different parts of the tooth surface corresponding to the inner surface 200 of the three-dimensional digital model of the shell-shaped dental instrument, it can be roughly divided into three parts: the lip-buccal part 201, the lingual part 203, and the occlusal surface part. 205.

In many cases, there is a gap between two adjacent teeth in the three-dimensional digital model of teeth. If the outer surface of the three-dimensional digital model of the tooth is directly used as the inner surface of the three-dimensional digital model of a shell-shaped dental instrument, it will be based on the inner surface. The cavity of the manufactured shell-shaped dental instrument that contains the teeth forms an entity that fills the gap between the teeth, which straddles the inner surface of the shell-shaped dental instrument between the labial and buccal parts and the lingual part, which may lead to shell-like dentistry. The equipment is difficult or even impossible to wear.

Therefore, in one embodiment, based on the three-dimensional digital model of teeth, a continuous surface that can wrap all the teeth and the gaps between the teeth can be generated as the inner surface of the three-dimensional digital model of the shell-shaped dental instrument. By controlling the rigidity or curvature of the part of the surface that covers the gap between the teeth, the depth of the surface into the gap is controlled, so that for each tooth and the adjacent tooth part (for two adjacent teeth with a gap, that is, the The part of the two teeth located in the gap), the surface at most only wraps and touches the part thereof, not completely wraps and touches the part. In other words, the surface at most only fills a part of the gap between the teeth, not completely.

Please refer to Figure 2B, which schematically shows the relationship between the inner surface of the three-dimensional digital model of the shell-shaped dental instrument and the three-dimensional digital model of the tooth in an embodiment of the present application. The view is along a plane perpendicular to the Z axis of the world coordinate system The cross-sectional view, for the sake of simplicity, this view only shows the inner surface of the 3D digital model of the shell-shaped dental instrument and a part of the 3D digital model of the tooth. The inner surface 200' wraps the teeth 211', 213', and 215', and wraps the gap 217' between the teeth 211' and 213' and the gap 219' between the teeth 213' and 215'. The inner surface 200' does not penetrate the slits 217' and 219'.

In one embodiment, computer software such as Materialise 3-matic, Simpleware, HyperMesh, etc. can be used to "wrap" the three-dimensional digital model of the tooth to produce a closed surface that wraps the three-dimensional digital model of the tooth, which can be wrapped The part of the tooth serves as the inner surface of the three-dimensional digital model of the shell-shaped dental instrument.

Please refer to FIG. 3A, which shows the interface when using Materialise 3-matic software to wrap the tooth three-dimensional digital model 301 in an embodiment of the present application.

Please refer to FIG. 3B, which shows the closed surface 303 obtained after wrapping the three-dimensional digital model 301 of the tooth using Materialise 3-matic software in an embodiment of the present application.

In some cases, there are missing teeth in the dentition. In one embodiment, virtual teeth or entities of corresponding shapes can be added to the positions of the missing teeth in the original three-dimensional digital model of teeth (the three-dimensional digital model of dentition with missing teeth) to fill the gap. Then, the inner surface of the shell-shaped dental appliance is generated based on the three-dimensional digital model of the tooth that fills the vacancy.

In 1015, the outer surface of the three-dimensional digital model of the shell-shaped dental instrument is generated.

In one embodiment, computer software such as Materialise 3-matic, Geomagic, Meshlab, and HyperMesh can be used to expand a predetermined distance outward along the method based on the inner surface of the shell-shaped dental instrument (that is, the thickness of the preset shell-shaped dental instrument) ) To obtain the outer surface of the shell-shaped dental instrument.

The function and performance of shell-shaped dental instruments are mainly determined by the geometry of the inner surface. Therefore, in addition to the method of expanding the inner surface by a predetermined distance, the outer surface of the shell-shaped dental instruments can also be obtained by other methods. produce. In one embodiment, the outer surface obtained by the external expansion may be smoothed, so that the transitions therefrom are more regionally relaxed. In another embodiment, based on the inner surface of the three-dimensional digital model of the shell-shaped dental instrument or the surface of the three-dimensional digital model of the tooth, a gentle arc can be generated by setting the minimum thickness as the outer surface of the three-dimensional digital model of the shell-like dental instrument. surface. A smoother and gentler outer surface can reduce the occurrence of stress concentration and help improve the mechanical properties of shell-shaped dental instruments.

In 1017, a three-dimensional digital model of the shell-shaped dental appliance is generated based on the inner surface and the outer surface of the three-dimensional digital model of the shell-shaped dental appliance.

In one embodiment, the inner and outer surfaces of the three-dimensional digital model of the shell-shaped dental instrument are respectively part of two closed surfaces (for example, the STL model), and a new closed surface can be established based on the inner and outer surfaces, namely A three-dimensional digital model of a shell-shaped dental instrument.

The following takes the operation in Geomagic software as an example to give a brief introduction to the process: first, flip the normal of the inner surface; then, combine the inner surface and the outer surface to create a separate object; then, use "Fill a single hole The "bridging" operation under "" connects the part of the position between the inner surface and the outer surface; finally, the "inner hole" operation under "filling a single hole" is used to fill the segment between the bridges. Under the enlightenment of this application, it can be understood that in addition to the Geomagic software, other software can also be used to generate a three-dimensional digital model of a shell-shaped dental instrument based on the inner surface and the outer surface, for example, HyperMesh, but the operation may be slightly different.

In one embodiment, after obtaining the three-dimensional digital model of the shell-shaped dental instrument, it can be cropped to remove the extra part of its edge, so that the shell-shaped appliance made by it can be used directly without the need to correct the shell-shaped appliance. The edges of the filter are cropped.

In one embodiment, the edges of the three-dimensional digital model of the shell-shaped dental instrument can be processed to eliminate sharp parts and make it rounded, so as to prevent the shell-shaped dental instrument made based on it from damaging the soft tissue of the patient when it is worn.

In 103, the three-dimensional digital model of the shell-shaped dental instrument is checked.

In one embodiment, a computer can be used to check whether the shell-shaped dental device represented by the shell-shaped dental device is qualified based on the three-dimensional digital model of the shell-shaped dental device.

In one embodiment, for a shell-shaped appliance, one aspect of judging whether it is qualified is to see whether it can reposition the teeth from the initial layout corresponding to the treatment step to the target layout. Under the enlightenment of this application, it can be understood that the inspection of the shell-shaped appliance can also include but is not limited to: whether the shell-shaped appliance is damaged during the wearing process; whether the orthodontic force of the moving tooth is in the wearing process Appropriate interval (different orthodontic movement design, different tooth position, the required appropriate orthodontic force interval may be different, if the orthodontic force is too small, it is not easy to move the mobile teeth, if the orthodontic force is too large, it may damage the periodontal tissue ); During the wearing process, whether the force of the anchorage tooth is reasonable; during the wearing process, whether the ratio of the translational force to the moment of the moving tooth is in the appropriate range; and whether the extraction force of the appliance is too large.

In one embodiment, the finite element analysis method may be used to verify the parametric three-dimensional digital model of the shell-shaped dental instrument. The following is an example for detecting whether the shell-shaped appliance can reposition the teeth from the initial layout corresponding to the treatment step to the target layout for detection.

In one embodiment, based on the parametric three-dimensional digital model of the shell-shaped dental instrument and the three-dimensional digital model of the dental jaw, the finite element models of the shell-shaped dental instrument and the dental jaw may be generated respectively. Then, in the finite element simulation environment, the finite element model of the shell-shaped dental instrument can be worn on the finite element model of the jaw, and based on the tooth layout and the load when the balance is reached, the parameterized three-dimensional digital model represents Whether shell-shaped dental instruments are qualified.

In one embodiment, when calculating the effect of the shell-shaped appliance on the teeth positioning based on the finite element simulation, in order to simplify the calculation, the biological process of the osteoclast of alveolar bone may not be considered.

In one embodiment, it can be assumed that the tooth is absolutely rigid (that is, no displacement), the static solution method is used to calculate the load of the tooth when the mechanical static equilibrium is reached, and the displacement of the tooth in the actual situation is calculated based on the calculated load, and based on This examines the parametric three-dimensional digital model of the shell-shaped dental instrument.

Since the periodontal ligament is an elastic body, when the tooth is loaded, it will be displaced due to the elastic deformation of the periodontal ligament, but when the load is removed, the periodontal ligament will return to its original shape. Accordingly, the displacement of the tooth will also be caused by the tooth. The peripheral membrane is restored to its original state and changed. In another embodiment, in order to more accurately calculate the effect of the shell-shaped appliance on the positioning of the teeth, the impact of the elastic deformation of the periodontal ligament and the restoration of the original shape on the positioning of the shell-shaped appliance can be included in the calculation.

In another embodiment, in order to make the simulation result closer to the actual situation, the finite element simulation can simulate the biological process of alveolar bone osteoclastogenesis. In one embodiment, a function f(σ, t) that changes with time and stress distribution can be used to express the biological process of osteoclast osteogenesis of alveolar bone. At this time, the finite element model of the dental jaw may include the finite element model of the crown, the root, the periodontal ligament, and the alveolar bone (which may include cortical bone and cancellous bone).

For the specific method of using finite element analysis to inspect the shell-shaped appliance, please refer to the Chinese Patent Application No. 201710130613.0 filed by Wuxi Times Angel Medical Device Technology Co., Ltd. on March 7, 2017. Validation Method of Device Manufacturing Process", Chinese Patent Application No. 201710130668.1 "Verification Method for Manufacturing Process of Shell-shaped Dental Devices Based on Hot Film Forming Technology" filed on March 7, 2017, filed on January 26, 2017 Chinese Patent Application No. 201710057418.X "Method for Inspection of Shell-shaped Dental Devices Based on Computer Finite Element Analysis", Chinese Patent Application No. 201710057403.3 "Shell-shaped Dental Devices Based on Computer Finite Element Analysis" was filed on January 26, 2017 Inspection Method of Apparatus Accessories” and Chinese Patent Application No. 201710286619.7 “Inspection Method of Computer Aided Orthodontic Orthodontic Appliances” filed on April 27, 2017.

In yet another embodiment, the parametric three-dimensional digital model of the shell-shaped dental instrument can be verified based on the simplified numerical model.

In one embodiment, in order to simplify the calculation, the biological process of the osteoclast of the alveolar bone during the correction process may not be considered, and the movement of the tooth can be estimated based on the force of the tooth under mechanical static equilibrium.

Please refer to FIG. 4, which schematically shows a simplified numerical model in an embodiment of the present application.

In this simplified numerical model, the alveolar bone 401 (the part of the alveolar bone that supports the mobile tooth), the periodontal ligament 403 (the periodontal ligament covering the root of the mobile tooth), the mobile tooth 405, the shell-like appliance 407, the anchorage The tooth 409, the periodontal ligament 411 (the periodontal ligament covering the anchorage tooth root), and the alveolar bone 413 (the part of the alveolar bone supporting the anchorage tooth) form an interactive chain.

In one embodiment, the shell appliance and the periodontal ligament can be simplified into different springs, and the parameters of each spring can be assigned by the root shape, tooth movement design, tooth arrangement position, and shell appliance shape. . The assignment of spring parameters can be based on the theoretical derivation of structural mechanics and continuum mechanics, or based on the mechanics database, or based on the above-mentioned all-element simulation method (that is, modeling materials, morphology, boundary conditions, etc.) that conform to the real situation. And based on such a finite element model for simulation). In one embodiment, the spring parameters may include tensile modulus and rotational modulus, which represent the stiffness of the tooth in translation and rotation, respectively. After assigning values to the springs in the model, the displacement of the moving teeth under the action of the shell-shaped appliance can be calculated, and based on this, it can be judged whether the shell-shaped appliance meets the design requirements.

Under the enlightenment of this application, it can be understood that in addition to the finite element method and simplified numerical model described above, it is also possible to sample the finite volume method (Finite Volume Method), the finite difference method (Finite Difference Method), and the domain decomposition method. , Finite point method, boundary element method and other methods to check the three-dimensional digital model of shell-shaped dental instruments.

If the test result shows that the three-dimensional digital model of the shell-shaped dental instrument is qualified, skip to 107, otherwise skip to 105.

In 105, the three-dimensional digital model of the shell-shaped dental instrument is modified according to the inspection result.

The inventor of the present application found that the force applied by the shell-shaped appliance to the tooth is directly related to the cross-sectional shape and cross-sectional area of the shell-shaped appliance. Please refer to Figure 5, which shows the force of the shell-shaped appliance on the teeth in the mesio-distal direction and the buccal-lingual direction under the premise that the cross-sectional shape of the shell-shaped appliance does not change significantly in an embodiment of the present application The relationship between the value and the cross-sectional area of the shell-shaped appliance. Among them, the curve 501 represents the relationship between the force value of the shell-shaped appliance and the cross-sectional area of the shell-shaped appliance on the teeth in the mesiodistal direction, and the curve 503 represents the value of the shell-shaped appliance under the tooth in the buccal and lingual direction. The relationship between the force value and the cross-sectional area of the shell-shaped appliance, and the interval 505 represents the ideal tooth force range, which can be used to guide the modification of the three-dimensional digital model of the shell-shaped appliance. In one embodiment, the curve 501 and the curve 503 can be obtained through experiments or simulations using statistical methods.

In one embodiment, if the test result shows that the corrective force of a certain tooth is too large or too small, the corresponding part of the shell-shaped appliance can be adjusted according to the curve shown in Figure 5 (for example, the shell-shaped appliance is connected to the The thickness of the part between the tooth and the adjacent tooth), so that the orthodontic force of the tooth is located in the ideal range 505.

In one embodiment, the three-dimensional digital model of the shell appliance may be an STL model. The appliance designer can manually select the three-dimensional number of the shell-shaped appliance through the user interface of the Geomagic Studio software based on the results of the inspection (for example, the specific conditions of the mesio-distal and buccal-lingual force on a certain tooth) The corresponding part of the model and the thickness of the part are modified to increase or decrease the cross-sectional area of this part of the three-dimensional digital model of the shell-like appliance, so that the orthodontic force of the corresponding tooth is located in the ideal interval 505.

In the Geomagic Studio software environment, the surface of the STL model can be expanded, corroded, and smoothed. The expansion operation is used to make the surface of the selected area bulge outward by a set distance, and the smoothness of the transition between the bulge area and the edge can be set. The etching operation is used to make the surface of the selected area concave by a set distance, and the smoothness of the transition between the concave area and the edge can also be set. The smoothing operation is used to smooth the surface of the selected area to make it smoother.

Under the enlightenment of this application, it can be understood that the inspection of the three-dimensional digital model of the shell-like appliance can include many other aspects in addition to the force of the teeth in the mesio-distal direction and the buccal and tongue directions, such as the bearing of the teeth. Whether the orthodontic force of the tooth is within a reasonable range, whether the anchorage force of the tooth is within a reasonable range, whether the anchorage distribution is reasonable, whether the shell-like appliance can reposition the tooth to the predetermined layout, and the removal of the shell-like appliance Whether the force is reasonable, etc.

After the modification is completed, skip to 103 to check the three-dimensional digital model of the modified shell-shaped dental instrument, and so on, until a qualified three-dimensional digital model of the shell-shaped dental instrument is obtained.

In 107, using 3D printing technology, a shell-shaped dental device is made based on the three-dimensional digital model of the shell-shaped dental device that has passed the inspection.

Currently, the more commonly used file formats for 3D printing include STL and STP. Although some manufacturers' 3D printing equipment supports OBJ, BREP, MAX, 3DM, 3DS, X_T, SKP, SLDPRT, PRT, ASM, F3D, FBX, RVT, WIRE and other format files, it is relatively rare.

If the three-dimensional digital model of the shell-shaped dental instrument that passed the inspection is an STL model, then it can be used directly to control the 3D printing equipment to make the shell-shaped dental instrument.

In one embodiment, before using the STL file to control the 3D printing device to perform 3D printing, it can be inspected and repaired to ensure that these triangular faces form a fully enclosed surface.

If the 3D digital model of the shell-shaped dental instrument that passes the inspection is not compatible with the 3D printing equipment, then based on its point cloud data, it can be converted into a file format compatible with the 3D printing equipment such as STL model, and then the converted file format can be used. File control 3D printing equipment to make shell-shaped dental instruments.

At present, 3D printing equipment suitable for manufacturing shell-shaped dental instruments includes light curing molding (Stereo Lithography Appearance, SLA) equipment (such as those provided by 3D Systems), and digital light processing (Digital Light Procession, DLP) equipment (such as Envision Equipment provided by TEC) and PolyJet equipment (such as equipment provided by Stratasys) and so on.

Although various aspects and embodiments of the present application are disclosed herein, under the inspiration of the present application, other aspects and embodiments of the present application are also obvious to those skilled in the art. The various aspects and embodiments disclosed herein are for illustrative purposes only, not for limiting purposes. The protection scope and spirit of this application are only determined by the appended claims.

Likewise, the various diagrams may show exemplary architectures or other configurations of the disclosed methods and systems, which are helpful in understanding the features and functions that can be included in the disclosed methods and systems. The claimed content is not limited to the exemplary architecture or configuration shown, and the desired features can be implemented with various alternative architectures and configurations. In addition, for flowcharts, functional descriptions, and method claims, the order of the blocks given here should not be limited to the various embodiments that are implemented in the same order to perform the functions, unless clearly indicated in the context .

Unless expressly stated otherwise, the terms and phrases used in this article and their variants should be interpreted as open-ended rather than restrictive. In some instances, the appearance of expansive words and phrases such as "one or more", "at least", "but not limited to" or other similar terms should not be understood as in examples where there may not be such expansive terms Intentions or needs indicate a narrowing situation.

Claims

A manufacturing method of shell-shaped dental instruments includes:

Obtain 3D digital models of shell-shaped dental instruments;

Checking the three-dimensional digital model of the shell-shaped dental appliance;

According to the result of the inspection, directly modify the three-dimensional digital model of the shell-shaped dental instrument; and

Using 3D printing technology, a shell-shaped dental instrument is produced based on the modified three-dimensional digital model of the shell-shaped dental instrument.
The method of manufacturing a shell-shaped dental appliance according to claim 1, wherein the shell-shaped dental appliance is a shell-shaped appliance for repositioning the teeth from the first layout to the second layout.
The manufacturing method of a shell-shaped dental appliance according to claim 1, wherein the inspection is based on finite element analysis.
The method of manufacturing a shell-shaped dental appliance according to claim 3, wherein the inspection includes at least one of the following: orthodontic force borne by teeth; anchorage force borne by teeth; displacement of teeth; anchorage distribution; and shell The extraction force of the shaped dental instrument.
The manufacturing method of the shell-shaped dental instrument according to claim 1, wherein the three-dimensional digital model of the shell-shaped dental instrument is an STL model.
The manufacturing method of a shell-shaped dental appliance according to claim 1, characterized in that it further comprises:

Obtain a three-dimensional digital model of the tooth; and

By performing a wrapping operation on the three-dimensional digital model of the tooth, a three-dimensional digital model of the shell-shaped dental appliance is generated.
The method of manufacturing a shell-shaped dental instrument according to claim 1, wherein the modification of the three-dimensional digital model of the shell-shaped dental instrument is a modification of its outer surface.
8. The manufacturing method of the shell-shaped dental appliance according to claim 7, wherein the modification of the three-dimensional digital model of the shell-shaped dental appliance is to change the local thickness of the shell-shaped dental appliance by modifying its outer surface.
8. The manufacturing method of a shell-shaped dental appliance according to claim 7, wherein the modification of the outer surface of the three-dimensional digital model of the shell-shaped dental appliance includes at least one of the following: expansion, corrosion, and smoothing.
The manufacturing method of the shell-shaped dental instrument according to claim 1, wherein the modification of the three-dimensional digital model of the shell-shaped dental instrument comprises:

The computer receives user instructions; and

The computer modifies the three-dimensional digital model of the shell-shaped dental instrument according to the user instruction,

Wherein, the user instruction is input by the user based on the inspection result and the three-dimensional digital model of the shell-shaped dental instrument graphically displayed on the user interface of the computer.