3D printed mouth piece containing deformation simulation

Abstract

A method of manufacturing a mouthpiece, in particular by ejecting droplets of a first drop of liquid material and a second drop of liquid material in a 3D printing process, the method comprising the steps of acquiring dental data of a user and inputting a model of the mouthpiece. A simulation is performed to determine a deformation of the input mouthpiece model as a function of the applied force. In accordance with the deformation, the input mouthpiece model is adapted to the working mouthpiece model by replacing at least a portion of the material of the input mouthpiece model with a replacement material. And finally, manufacturing the oral cavity part according to the optimized working oral cavity part model.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing an oral component. In particular, a method for manufacturing by single droplet additive deposition by a jet head, more particularly by jetting drops of a first droplet material and a second droplet material. The method comprises the following steps:

[0002] Acquiring dental data of a user, including a 3D tooth model of a virtual upper jaw and / or a virtual lower jaw similar to the upper jaw and / or the lower jaw in the mouth of the user;

[0003] Obtaining an input oral part model;

[0004] performing a simulation, during which the input mouthpiece model is placed on at least one of the virtual upper jaw and the virtual lower jaw;

[0005] adjusting the input oral part model to a working oral part model;

[0006] A mouthpiece is manufactured according to the working mouthpiece model. Background Art

[0007] US10188485B2 discloses a dental appliance that can protect teeth from clenching and grinding. The dental appliance includes a shell frame, and a tooth groove is formed in the length direction of the shell frame. The shell frame is composed of a layered structure, including a first shell layer made of a hard material and a second shell layer made of a soft material, and the second shell layer is located inside the first shell layer. The core frame made of the hard material is located in the tooth groove and has a tooth contact surface that matches the impression shape of the end portion of a plurality of teeth.

[0008] The dental appliance has excellent durability and wearing comfort. It can protect teeth from strong biting forces when clenching or grinding teeth. The dental appliance includes a mouthpiece that can be worn on the teeth to protect the teeth from external force impacts applied to the face by punches or balls during martial arts or ball sports, and the mouthpiece can be customized for the individual.

[0009] W02012 / 140021 discloses a method for customized manufacturing of orthodontic appliances, comprising a simulation step.

[0010] Orthodontic appliances can have a variety of implementations. In some embodiments, the orthodontic appliance is selected from a combination consisting of: braces, brackets, splints, retainers, archwires, aligners, and housings. In some embodiments, the virtual orthodontic appliance is configured to provide a manufactured orthodontic appliance that can prevent patients from grinding their teeth. In some embodiments, the virtual orthodontic appliance is configured to provide a manufactured orthodontic that is comfortable for patients to wear. In some embodiments, the function of the orthodontic appliance is to protect teeth, for example, some orthodontic appliances include mouth guards. Orthodontic appliances may include tooth protectors.

[0011] In the method, a virtual orthodontic appliance is generated, which includes a first part for positioning on a first part of a virtual 3D model of a patient's teeth. The virtual 3D tooth model includes a virtual upper jaw and a virtual lower jaw, which simulate the upper jaw and the lower jaw in the patient's mouth, respectively. In the method, an initial shape of the virtual orthodontic appliance is provided. Virtual orthodontic appliances predefined in a library can be selected to provide an initial virtual orthodontic appliance. A target virtual dynamic occlusion of a set of teeth is determined. Virtual dynamic occlusion is performed on the virtual orthodontic appliance anatomically correctly positioned on the 3D model, and the virtual orthodontic appliance is adjusted according to the results of the virtual dynamic occlusion.

[0012] In some embodiments, the method includes determining a target contact distribution between a virtual orthodontic appliance and a portion of a virtual 3D tooth model. When an orthodontic appliance manufactured according to the virtual orthodontic appliance is placed on the patient's teeth, the portion of the orthodontic appliance corresponding to the target contact distribution will contact the patient's teeth. The effect threshold is related to the measurement results of the contact distribution on one or more surfaces of the teeth, for example, the orthodontic appliance manufactured by the current virtual model contacts the occlusal surface of the tooth during occlusion. The effect threshold may include a two-dimensional mapping of the contact distribution on all of these occlusal surfaces in the first part of the virtual 3D tooth model, or a two-dimensional mapping on a selected tooth. If the results of the virtual dynamic occlusion show that the current contact distribution differs from the target contact distribution by more than a contact threshold, the virtual orthodontic appliance can be adjusted.

[0013] In some embodiments, the effect of an orthodontic appliance on a patient is estimated by using a distribution of collision points measured using a virtual dynamic occlusion. Collision points may occur during collisions between portions of a virtual orthodontic appliance and portions of a virtual 3D tooth model. In some embodiments, the method includes adjusting the virtual orthodontic appliance based on the estimated effect of the orthodontic appliance.

[0014] Different techniques can be used to manufacture orthodontic appliances based on virtual orthodontic appliances. Manufacturing techniques can include wax casting, 3D printing, milling, and metal component molding, such as cable and sheet molding. These techniques can be used alone or in combination. The manufacture of orthodontic appliances can include a dual-material process, where different parts of the orthodontic appliance are manufactured using different materials.

[0015] In some embodiments, when generating a virtual orthodontic appliance, the properties of the material used to manufacture the orthodontic appliance are also considered. The generation process of the virtual orthodontic appliance includes determining the properties of the material. For example, when manufacturing the tooth contact surface of the orthodontic appliance, the use of a flexible material can allow some chamfers to be generated on the lower part of the tooth, which can make the retainer more firmly fixed on the patient's teeth.

[0016] In some embodiments, the virtual orthodontic appliance is adjusted by an additive process or a subtractive process in which material is added or removed from the virtual orthodontic appliance, such as simulated addition or simulated removal of material on adjusted surfaces of the first and / or second portions of the virtual orthodontic appliance.

[0017] One disadvantage of this method of manufacturing orthodontic appliances is that the final manufactured mouthpiece product may be of poor quality. In particular, it is desirable to have a suitable method for adjusting an input mouthpiece model to a working mouthpiece model to improve the quality of the manufactured mouthpiece.

[0018] With respect to the above-mentioned prior art, the discussion of documents, procedures, materials, equipment, articles, etc. is merely to provide a background for the present invention and any of these matters should not be considered to constitute part of the prior art or general knowledge in the relevant field before the priority date of each claim of this application. Summary of the invention

[0019] A general object of the present invention is to at least partially obviate the above-mentioned disadvantages and / or to provide a usable alternative.More specifically, an object of the present invention is to provide a method for manufacturing a mouthpiece based on an improved working mouthpiece model.

[0020] According to the invention, this object is achieved by a method according to claim 1. In particular, the method is used for manufacturing a mouthpiece by 3D printing. More specifically, the mouthpiece is manufactured by additive deposition of drops from a jet head, more specifically by jetting drops of a first drop material and a second drop material, which are different and allow manufacturing the mouthpiece by a combination of soft and hard materials.

[0021] In one step of the method, dental data of the user is acquired. The dental data is used to manufacture customized oral parts. The dental data includes a 3D tooth model of a virtual upper jaw and / or a virtual lower jaw that is similar to the upper jaw and / or lower jaw in the user's mouth. The dental data can be obtained in a variety of ways, such as scanning the oral cavity using a scanning device. Intraoral scanners for acquiring individual oral information are generally known.

[0022] In one step of the method, an input mouthpiece model is obtained. The input mouthpiece model can be obtained from a library file that defines preset shapes of the mouthpiece to be manufactured. The input mouthpiece model can represent any kind of mouthpiece, such as an occlusal splint or a mandibular protrusion device, the latter including an upper splint and a lower splint. The mouthpiece to be manufactured can be configured to cover the mandibular or maxillary teeth or only a portion of the user's teeth. The mouthpiece can be used for any purpose, such as for tooth position adjustment, treatment of bruxism, as a sports protection mouthpiece, etc.

[0023] In one step of the method, a simulation is performed, during which the input mouthpiece model is placed on at least one of the virtual upper jaw and the virtual lower jaw. In the simulation, a deformation of the input mouthpiece model under a force is determined. The applied force may be a bite force or an external impact force, such as a force generated by teeth grinding or a force that occurs in sports such as martial arts.

[0024] In particular, in the method, bite forces are simulated to obtain a deformation of the input mouthpiece model. The bite force input values ​​obtained in the method may be standardized bite forces recognized in the literature and applicable to a specific user group or a specific treatment. More preferably, the bite force input values ​​in the simulation are personalized to a specific user. The bite force input values ​​may include measured data that are uploaded as bite force inputs for simulation for individual users.

[0025] The deformation of the input oral part model provides information about the stresses occurring in certain parts of the oral part. The deformation provides information on how the input oral part model should be adjusted to a working oral part model, which will serve as the basis for 3D printing the oral part. Preferably, the simulated deformation of the oral part is presented to the operator via a color map. The different colors in the figure visualize the parts of the input oral part model that need to be adjusted. The operator can examine the presented deformation and decide how to adjust the input oral part model to obtain a suitable working oral part model. In one embodiment, the method may include controlling an electronic device that can programmatically adjust the input oral part model based on the determined deformation. Based on software rules, the input oral part model can be adjusted and can be re-simulated to obtain a working oral part model that provides acceptable deformation under the action of applied forces.

[0026] In one step of the method, the input mouthpiece model is adapted to a working mouthpiece model by replacing at least a portion of the material of the input mouthpiece model with a substitute material. After at least one adaptation, the mouthpiece can be manufactured, in particular by 3D printing technology, based on the working mouthpiece model.

[0027] The advantage of the method of the present invention is that the deformation of the oral part caused by the force applied during use can be simulated, and the unexpected deformation of the oral part can be reflected in time. Some small local plastic deformations may be such unexpected deformations. Unexpected deformations may affect the wearing comfort of the oral part. In more serious cases, the deformation of the simulated oral part may be so large that the oral part loses its function during use. In extreme cases, the deformation may even cause local cracks in the oral part.

[0028] By performing simulations, unintended deformations can be detected at an early stage before the actual manufacture of the mouthpiece. If the simulation shows that unacceptable deformations exist, the input mouthpiece model is adjusted by replacing local material with substitute material to reduce or increase the deformations that occur. The substitute material replaces the material previously defined in the input mouthpiece model, locally hardening or softening the mouthpiece to adjust the deformations that occur to an acceptable range.

[0029] Preferably, the steps of simulating deformation and adapting the input mouthpiece model are repeated until a final working mouthpiece model is obtained to serve as a basis for 3D printing the mouthpiece. In a preferred iterative process, the simulation will be performed multiple times on the adjusted input mouthpiece model containing the substitute material to evaluate the adjusted deformation.

[0030] Preferably, the input mouthpiece model is arranged to be initially made of a single material. Before performing a first simulation, the input mouthpiece model, a reference input mouthpiece model, comprises a single material, in particular a soft printing material. The simulation is started from the input mouthpiece model of the single material. Preferably, the single material of the input mouthpiece model is softer than the alternative material. After the steps of performing the simulation and adjusting, the input mouthpiece model is adjusted and comprises at least partially a portion of the alternative material.

[0031] According to one embodiment of the method of the present invention, the composition of the replacement material only includes hard printing material. The hard printing material can be used to replace the material portion of the input mouthpiece model that is affected by the greatest deformation. The operator can specify the area or block to be replaced with the replacement material. In the portion with the greatest deformation, the greatest stress will occur. By replacing with hard material, the amount of deformation will be reduced. In this way, the fit and functionality of the mouthpiece to the upper or lower jaw can be improved. Better tooth protection can be obtained and bruxism can be prevented.

[0032] 3D printed soft or hard materials are usually defined by a predetermined flexural strength. Typical flexural strengths of soft printed materials range from at least 1.0 MPa to at most 10 MPa, especially about 2.0 MPa. Typical flexural strengths of hard materials range from at least 60 MPa, especially at least 80 MPa.

[0033] According to one embodiment of the method of the present invention, the substitute material may be a mixture of a hard printing material and a soft printing material. The substitute material may be a mixture of multiple printing materials, containing at least a certain amount of hard printing material and soft printing material. The substitute material contains a specific mixing ratio of hard printing material and soft printing material. The mixture is suitable for replacing those parts of the material that are subjected to medium stress. The medium stress value is between the maximum and minimum stresses corresponding to the maximum and minimum deformations simulated.

[0034] According to one embodiment of the method of the present invention, the mixing ratio of the mixture of hard printing material and soft printing material at the expected simulated deformation can be determined empirically. For the printing process, a mixing ratio can be set when a certain deformation is determined in the simulation step. On this basis, the mixing ratio can be defined in a suitable way to fully predict the deformation that will occur.

[0035] According to one embodiment of the method of the present invention, the mixing ratio of the mixture of hard printing material and soft printing material is proportional to the deformation. In the method, it is assumed that there is a linear dependence between the simulated deformation and the alternative material mixing ratio. Preferably, the volume ratio of the mixture is linearly related to the degree of deformation. In order to adapt, the mixture does not contain hard material in the part with the smallest deformation and does not contain soft material in the part with the largest deformation. For deformations between the minimum and maximum deformations, the mixture contains a certain amount of hard printing material and soft printing material in a certain proportion. Preferably, the oral part is manufactured by a 3D printer, and the 3D printer includes a nozzle for ejecting the first and second drop materials. Preferably, one of the first and second drop materials is defined as a hard material and the other is defined as a soft material.

[0036] According to an embodiment of the method of the present invention, the simulated deformation is subdivided into at least three levels, for example, including strong deformation, weak deformation and medium deformation.

[0037] Preferably, the input mouthpiece model is gridded. The gridded input mouthpiece model may be subdivided into slices, a particular slice comprising a pixel matrix.

[0038] According to an embodiment of the method of the present invention, the method comprises the steps of assigning a substitute material to the surface voxels and assigning a substitute material to the internal voxels. Preferably, in the steps of the method, local deformations are first determined on the surface voxels of the input oral component model, in particular on the tooth contact surface, to simulate the deformation on the contact surface, and then the deformations on the internal voxels are determined.

[0039] According to one embodiment of the method of the invention, the simulation provides deformations only on the surface voxels. Based on the deformation of the surface, the material properties of the part can be defined with a certain depth. In the adaptation software, an algorithm can be defined to define the properties of the internal material based on the deformation of the surface. At least two input parameters can be used to define the properties of the internal material, wherein the two input parameters include the penetration depth and the gradient of the transition between the materials.

[0040] According to one embodiment of the method according to the invention, the deformation of the input mouthpiece model is defined by means of a deformation model. In one step, at least one deformation portion is assigned. The position of a deformation portion having a specific deformation, such as a weak deformation, a strong deformation or a medium deformation, is determined. Preferably, the depth of a certain deformation portion is also determined in order to determine the volume of the deformation portion to be adjusted. In the steps of the method, the deformation portion is at least partially replaced by a substitute material, which corresponds to the determined amount of deformation. Preferably, the input mouthpiece model is subdivided into slices, in particular after simulation, in the working mouthpiece model, the drip material of a specific slice is defined in a separate bitmap.

[0041] Furthermore, the invention relates to a 3D printer comprising control electronics capable of being programmed to perform the method according to the invention.

[0042] Furthermore, the present invention relates to a computer program product comprising a computer-readable medium containing computer-readable code, wherein the computer-readable code is configured such that, when executed by a suitable computer or processor, the computer or processor performs the method according to the present invention.

[0043] Furthermore, the invention relates to a mouthpiece defined according to the method according to the invention.

[0044] According to an embodiment of the mouthpiece according to the invention, the mouthpiece has a local patch configured to compensate for unacceptable deformations. The local patch is defined by the volume of at least one voxel. In particular, the volume of the local patch is at most 0.3 cubic centimeters, in particular at most 0.1 cubic centimeters.

[0045] According to one embodiment of the mouthpiece of the present invention, the local patch is located at a customer-specific location to obtain a customized mouthpiece. According to the method of the present invention, the use of the local patch is particularly conducive to customizing the mouthpiece according to the specific situation of the user, such as compensating for an individual's missing teeth. Compensating for these user-specific factors, the mouthpiece has at least one local patch of replacement material according to the compensation result for a specific customer.

[0046] According to one embodiment of the mouthpiece of the present invention, the local patch of replacement material is located below the surface of the mouthpiece. In this case, the local patch is completely embedded in the mouthpiece. The local patch is applied to a certain depth of the mouthpiece, for example, at a depth of 3 mm. In this way, the local patch can compensate for or handle unacceptable deformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The present invention will be further described in detail with reference to the accompanying drawings. According to the present invention, the accompanying drawings show actual embodiments, which should not be interpreted as limiting the scope of the present invention. Specific features can also be considered separately from the illustrated embodiments and can be considered as distinguishing features in a broader context. At the same time, specific features are not only applicable to the illustrated embodiments, but can also be used as common features of all embodiments falling within the scope of the claims, where:

[0048] Figure 1 A flow chart of a method according to an embodiment of the present invention is shown, comprising a deformation simulation of an input mouthpiece model.

[0049] Figure 2 The deformation model including different deformation areas obtained by simulation is shown;

[0050] Figure 3 and Figure 4 The working mouthpiece model obtained after adapting the input mouthpiece model is shown as a basis for manufacturing the mouthpiece;

[0051] Figure 5 The ratio relationship of the hard and soft substitute material mixture corresponding to the simulated deformation of the input mouthpiece model is shown. Specific embodiments

[0052] Figure 1 A flow chart of an embodiment of a method for manufacturing a mouthpiece according to the present invention is shown.

[0053] In the first step of the method, dental data is obtained. The user's dental data includes a 3D tooth model of a virtual upper jaw and / or a virtual lower jaw. The dental data can be obtained by performing a scanning process using a scanning tool.

[0054] In one step of the method, an input mouthpiece model is obtained. The input mouthpiece model is preferably from a library. Preferably, the input mouthpiece model is defined by a single material.

[0055] In another step of the method, a simulation is performed. In the simulation, the input mouthpiece model is placed on at least one of the virtual upper jaw and / or the virtual lower jaw. For example, the input mouthpiece model can represent a night guard mouthpiece worn on the upper jaw of the user. In the simulation, a virtual articulator can be used to determine the deformation of the input mouthpiece model under the action of force. Preferably, this simulated applied force represents the bite force of the individual user. In this way, a deformation model can be obtained.

[0056] Figure 2The example in Figure 2 shows such a deformation model. The deformation model is presented in the form of a color map, where different colors are shaded. Different colors represent different deformations, and each color represents a deformation 21, 22, 23 at a certain position on the input oral piece model 20. The color map of the deformation model intuitively shows the operator which positions need to be adapted to the input oral piece model in order to obtain a suitable working oral piece model that can be used to manufacture the oral piece. In a more advanced implementation method, the control electronic device can be programmed according to predetermined program rules to adapt the input oral piece model. The control electronic device may include an algorithm for presenting a specific deformation to adapt the input oral piece model according to the applied force.

[0057] Here Figure 2 , the color map of the deformed model shows the parts that are subjected to strong deformation 23, weak deformation 21 and medium deformation 22. Initially, the input mouthpiece model can be configured from a single material. The first obtained deformed model 2 can show the parts of the input mouthpiece model that need to be replaced with alternative materials in the first adaptation step. Preferably, the simulation and adaptation steps of the input mouthpiece model are performed in an iterative manner until the final working mouthpiece model is obtained as a basis for manufacturing the mouthpiece.

[0058] In one step of the method, a working mouthpiece model 3 is obtained. The working mouthpiece model 3 can be visualized in simulation software. Figure 3 and Figure 4 An example of a working mouthpiece model 3 is shown, which is similar to a bite splint, wherein Figure 4 yes Figure 3 3. The working mouthpiece model has a tooth contact surface 31, an inner surface 32, an outer surface 33 and an occlusal surface 33. The tooth contact surface refers to the part of the bite splint facing one or more teeth of the user when in use. Here, the tooth contact surface includes soft material and hard material, while the occlusal surface includes only hard material.

[0059] The portion of the deformation model determined to be subjected to medium deformation can be defined by a body of material having medium hardness in the working mouthpiece model. The mouthpiece is preferably manufactured by 3D printing, more preferably by additive deposition of drops from a nozzle. Specifically, the method of the present invention is used to manufacture the mouthpiece by a 3D printing process, wherein drops of multiple materials or drops of different materials are ejected through a nozzle.

[0060] Preferably, the first drop material and the second drop material are sprayed during the printing process. The first drop material and the second drop material can be combined during the printing process to obtain a material body corresponding to the material body in the working mouthpiece model. One of the first drop material and the second drop material is defined as a soft material, and the other is defined as a hard material.

[0061] Different drop materials can be specified based on different physical properties. For example, a first drop material can be selected based on a certain elasticity defined by a Young's modulus, while a second drop material can be selected based on another elasticity defined by another Young's modulus. The body of material contains a certain amount of drops containing the first and second drop materials, thereby producing a medium elasticity defined by the drops contained by the first material and the second material.

[0062] like Figure 5 As shown, in the method, a corollary may be included, that is, the simulated deformation of the input mouthpiece model is proportional to a certain elasticity of the material body. The control electronics of the 3D printer may include the corollary to perform the method. The maximum deformation corresponds to a material body composed entirely of soft drop material, and the minimum deformation corresponds to a material body composed entirely of hard drop material. The medium deformation corresponds to the first and second drop materials mixed in proportion.

[0063] Although the present invention has been described in detail, it is obvious to those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as subsequently claimed, and all such changes and modifications shall be included within the scope of the present disclosure and claims.

[0064] In addition, it is particularly pointed out that any features of the method according to the present invention described in the embodiments and / or mentioned in the dependent claims are patentable in themselves, without relying on other presented features. In particular, any measures proposed in the dependent claims are also patentable, without relying on the independent claims.

[0065] Therefore, the present invention provides a method and a 3D printer for performing the method to manufacture an oral part, in particular by spraying drops of a first drop material and a second drop material during a 3D printing process. The method includes the steps of obtaining dental data of a user and inputting an oral part model. A simulation is then performed to determine the deformation of the input oral part model after a force is applied. Based on the deformation, the input oral part model is adapted and adjusted by replacing at least a portion of the material with an alternative material, thereby obtaining a working oral part model. Finally, the oral part is manufactured based on the optimized working oral part model.

Claims

1. A method for manufacturing a mouthpiece, in particular by droplet additive deposition with a jet head, more particularly by jetting drops of a first droplet material and a second droplet material, characterized in that The following steps are involved: Acquire dental data of a user, the dental data comprising a 3D tooth model of a virtual upper jaw and / or a virtual lower jaw similar to an upper jaw and / or a lower jaw in a mouth of the user; Acquire an input oral component model, wherein the input oral component model defines a preset shape of the oral component to be manufactured; performing a simulation, during which the input mouthpiece model is placed on at least one of the virtual upper jaw and the virtual lower jaw, and a deformation of the input mouthpiece model is determined based on an applied force; Adapting the input mouthpiece model to a working mouthpiece model by replacing at least a portion of the material of the input mouthpiece model with a substitute material; The oral cavity part is manufactured according to the working oral cavity part model, in particular by 3D printing technology.

2. The method according to claim 1, characterized in that The steps of simulating deformation and adapting the input mouthpiece model are repeatedly performed until a final working mouthpiece model is obtained to be used as a basis for manufacturing the mouthpiece.

3. A method according to any one of the preceding claims, characterized in that The input mouthpiece model is initially defined by a single material, particularly a material that is softer than the replacement material.

4. A method according to any one of the preceding claims, characterized in that In an initial step before the first simulation, the material of the input oral part model is defined by a soft printing material having a predetermined flexural strength, in particular the predetermined flexural strength is in the range of at least 1.0 MPa and at most 10 MPa, in particular about 2.0 MPa.

5. A method according to any one of the preceding claims, characterized in that The composition of the replacement material comprises only hard printing material having a predetermined flexural strength, in particular the predetermined flexural strength is at least 60 MPa, more particularly 80 MPa.

6. A method according to any one of the preceding claims, characterised in that The substitute material is a mixture, and the mixture contains at least a certain amount of hard printing material and a certain amount of soft printing material.

7. The method according to claim 6, characterized in that The content of hard material in the mixture of the substitute material and the determined minimum deformation ε min and determine the maximum deformation ε max A certain deformation between x proportioned so that the mixture is at minimum deformation ε min The part does not contain hard material and at the maximum deformation ε max The part does not contain soft material.

8. A method according to any one of the preceding claims, characterised in that The deformation ε of the mouthpiece is simulated by applying a biting force, wherein in particular the biting force is personalized for a specific user, thereby obtaining a customized mouthpiece.

9. A method according to any one of the preceding claims, characterised in that The method includes the steps of assigning a substitute material to surface voxels and assigning a substitute material to interior voxels.

10. The method according to claim 9, characterized in that Prior to assigning substitute materials to the interior voxels, substitute materials are assigned to the surface voxels.

11. The method according to claim 9 or 10, characterized in that In the simulation step, after only the surface deformation is determined, the substitute material of the internal voxels is determined according to the obtained surface deformation.

12. A method according to any preceding claim, characterised in that The simulated deformation of the input mouthpiece model is defined by a deformation model, wherein at least one deformation part is provided in the deformation model.

13. The method according to claim 12, characterized in that The depth of the deformed portion is determined, wherein in particular the input mouthpiece model is subdivided into slices, in particular after simulation, in the working mouthpiece model, the drip material for a specific slice being defined in a separate bitmap.

14. A mouthpiece obtainable by a method as claimed in any preceding claim.

15. The oral device according to claim 14, characterized in that: The mouthpiece has a local patch of replacement material, which is provided to compensate for unacceptable deformations, wherein in particular the volume of the local patch is at most 0.3 cm 3 , especially up to 0.1 cm 3 .

16. The oral device according to claim 15, characterized in that: The localized patches of replacement material are placed at customer-specific locations to achieve a customized mouthpiece.

17. The oral device according to claim 16, wherein: The local patch is placed at the location of the missing tooth of a particular client.

18. The oral device according to claim 16 or 17, characterized in that: The localized patch of replacement material is located beneath a surface layer of the mouthpiece.

19. A 3D printer comprising control electronics, characterized in that: The control electronics are programmed to carry out a method as claimed in any preceding claim.

20. A computer program product comprising a computer readable medium, characterized in that The computer readable medium contains computer readable code, which is configured, when executed by a suitable computer or processor, to cause the computer or processor to perform the method according to any one of claims 1-13.

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