Mouthpiece and method for manufacturing the same

Abstract

Provided are a mouthpiece and a mouthpiece manufacturing method in which an annular lamination mark can be prevented from being formed in a front teeth part. In this manufacturing method for a mouthpiece (orthodontic aligner (20)) that is manufactured by a laminate molding device (30) and that is mounted in an oral cavity so as to cover teeth (10), the mouthpiece (orthodontic aligner (20)) is manufactured by laminating curing layers (25) such that no annular lamination mark is formed in a buccal part (22) which covers buccal surfaces (12) of front teeth (central incisor teeth (10a), lateral incisor teeth (10b), canine teeth (10c)).

Description

[Technical Field]

[0001] The present invention relates to a mouthpiece that is manufactured using an additive manufacturing apparatus and is worn in the oral cavity to cover the teeth, and a method for manufacturing the mouthpiece. [Background technology]

[0002] Methods for manufacturing a mouthpiece using an additive manufacturing device are known (see, for example, Patent Documents 1 and 2).

[0003] Patent Document 1 describes a configuration in which orthodontic aligners are produced using a 3D printer based on the patient's dentition data. This allows the aligner to be directly shaped, eliminating the need to create a male mold as with existing aligners, shortening the process and reducing costs.

[0004] Patent Document 2 also describes a configuration in which a bite splint is produced using a 3D printer based on the patient's dentition data. This allows for the production of a bite splint that can accurately set the normal positional relationship between the upper and lower jaws of a patient with jaw deformity after maxillary and maxillary osteotomy surgery. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-94245 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-81747 Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, the way layering marks remain on objects created with a 3D printer varies depending on the modeling direction (layering direction). In particular, in the case of a shape such as a dome, in which large surfaces are layered in order from small surfaces, annular layering marks, like tree rings, are formed on the surface of the completed object. When manufacturing an object shaped like a mouthpiece, these annular layering marks are always formed somewhere on the object. The inventors discovered that if these annular layering marks are formed on the front teeth, the aesthetics are significantly impaired.

[0007] Natural teeth rarely have regular circular patterns. On the other hand, circular layer marks tend to scatter light, making it impossible to obtain the translucency of natural teeth. This can cause discomfort when wearing a mouthpiece or other device with circular layer marks on the front teeth. Furthermore, the aesthetics of the front teeth affect facial appearance. Therefore, if the aesthetics of the front teeth are reduced, the patient's quality of life (QOL) will be significantly reduced.

[0008] However, Patent Documents 1 and 2 do not describe the layering direction (modeling direction) in which orthodontic aligners and bite splints are manufactured using a 3D printer. As a result, the aligner described in Patent Document 1 and the bite splint described in Patent Document 2 have the problem of forming annular layering marks on the front teeth.

[0009] Therefore, an object of the present invention is to provide a method for manufacturing a mouthpiece that can prevent the formation of annular lamination marks in the front teeth area. [Means for solving the problem]

[0010] In order to achieve the above-mentioned object, the method for manufacturing a mouthpiece of the present invention is a method for manufacturing a mouthpiece that is manufactured using an additive manufacturing device and is worn in the oral cavity to cover the teeth, and is characterized in that the mouthpiece is manufactured by laminating hardened layers on the cheek side portions that cover the cheek surfaces of the front teeth so that ring-shaped lamination marks are not formed.

[0011] In order to achieve the above-mentioned object, the mouthpiece of the present invention is a mouthpiece that is worn in the oral cavity so as to cover the teeth, and is characterized in that it does not have annular layer marks on the cheek side portion that covers the cheek surfaces of the front teeth. [Effects of the Invention]

[0012] The mouthpiece and method of manufacturing the mouthpiece of the present invention configured in this manner can prevent annular lamination marks from being formed in the front teeth area. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is an exploded perspective view showing an orthodontic aligner and a lower jaw according to a first embodiment. [Figure 2] FIG. 1 is a cross-sectional view of a molar showing the state in which the orthodontic aligner of Example 1 is attached to a tooth model at a target orthodontic position in three-dimensional data. [Figure 3] 1 is a flowchart illustrating a method for manufacturing an orthodontic aligner according to the first embodiment. [Figure 4] 1A to 1C are diagrams illustrating the additive manufacturing process of Example 1. [Figure 5] 1A to 1C are diagrams illustrating the additive manufacturing process of Example 1. [Figure 6] 1A to 1C are diagrams illustrating the additive manufacturing process of Example 1. [Figure 7] FIG. 1 is a side view showing a model produced by the additive manufacturing process of Example 1. [Figure 8] FIG. 10 is a diagram showing the front teeth portion of an orthodontic aligner shaped at an angle θ=0°. [Figure 9] FIG. 10 shows the front teeth portion of an orthodontic aligner shaped at an angle θ=30°. [Figure 10] FIG. 10 shows the front teeth portion of an orthodontic aligner shaped at an angle θ=60°. [Figure 11] FIG. 10 shows the front teeth portion of an orthodontic aligner shaped at an angle θ=90°. [Figure 12] FIG. 10 is a side view showing a model produced by the additive manufacturing process of Example 2. [Figure 13] FIG. 10 is a cross-sectional view of the hardened layer of the orthodontic aligner of Example 2. [Figure 14] FIG. 10 is a perspective view illustrating a method for manufacturing an orthodontic aligner according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments for realizing a mouthpiece and a method for manufacturing a mouthpiece according to the present invention will be described based on Examples 1 and 2 shown in the drawings. [Example]

[0015] The mouthpiece in Example 1 is applied to an orthodontic aligner that is worn in the oral cavity to cover the teeth of the lower jaw.

[0016] [Configuration of orthodontic aligners] Fig. 1 is an exploded perspective view showing the orthodontic aligner and lower jaw of Example 1. Fig. 2 is a cross-sectional view of a molar showing the orthodontic aligner of Example 1 attached to a tooth model at an orthodontic target position in 3D data. The configuration of the orthodontic aligner of Example 1 will be described below.

[0017] In the figure, teeth 10 are shown before orthodontic treatment, and tooth model 10A is shown at the orthodontic target position. Also, as shown in Figure 1, the part of orthodontic aligner 20 that covers front teeth 14 is referred to as front tooth portion 24.

[0018] The orthodontic aligner 20 is formed by an additive manufacturing device based on three-dimensional data created so as to fit closely to a tooth model 10A at the orthodontic target position, as shown in Figure 2. The orthodontic aligner 20 is attached to the teeth 10 before orthodontic treatment, and corrects the teeth 10 to the orthodontic target position.

[0019] (tooth structure) 1, tooth 10 has a crown made up of an occlusal surface 11, a buccal surface 12, and a lingual surface 13. Tooth 10 is supported by gums 15 surrounding the base of tooth 10.

[0020] The occlusal surface 11 is the end portion of the upper and lower teeth on the occlusal side, and refers to the occlusal surface of a molar.

[0021] (Configuration of tooth model) 2, the tooth model 10A is composed of an occlusal surface model 11A corresponding to the occlusal surface 11, a buccal surface model 12A corresponding to the buccal surface 12, and a lingual surface model 13A corresponding to the lingual surface 13 in the molar portion. The tooth model 10A is composed of a buccal surface model 12A corresponding to the buccal surface 12, and a lingual surface model 13A corresponding to the lingual surface 13 in the anterior portion.

[0022] (Configuration of orthodontic aligners) As shown in Figures 1 and 2, the orthodontic aligner 20 is formed in a groove-like shape with an occlusal portion 21, a buccal portion 22, and a lingual portion 23 in the molar portion. The orthodontic aligner 20 is formed in a groove-like shape with a buccal portion 22 and a lingual portion 23 in the anterior tooth portion. The orthodontic aligner 20 is detachably attached to the crowns of the lower jaw teeth. The orthodontic aligner 20 is formed in a groove-like shape so as to cover the crowns of all the teeth 10 of the lower jaw.

[0023] The occlusal portion 21 is formed in a shape that follows the occlusal surface model 11A of the tooth model 10A, as shown in Fig. 2. That is, the occlusal portion 21 is formed in a shape that covers the occlusal surface model 11A.

[0024] The cheek side portion 22 is formed in a shape that follows the cheek side surface model 12A of the tooth model 10A. That is, the cheek side portion 22 is formed in a shape that covers the cheek side surface model 12A.

[0025] The tongue side portion 23 is formed into a shape that follows the tongue side surface model 13A of the tooth model 10A. That is, the tongue side portion 23 is formed so as to cover the tongue side surface model 13A.

[0026] The orthodontic aligner 20 configured in this manner is worn so as to cover the crowns of all of the lower jaw teeth 10. The teeth 10 on which the orthodontic aligner 20 is worn are corrected to the orthodontic target position.

[0027] A plurality of orthodontic aligners 20 are prepared to gradually correct the teeth 10 to the final orthodontic target position. Each orthodontic aligner 20 is formed into a shape that can correct the teeth 10 by moving them by, for example, about 0.25 mm.

[0028] [Manufacturing method for orthodontic aligners] Fig. 3 is a flowchart illustrating a method for manufacturing the orthodontic aligner 20 of Example 1. Figs. 4 to 6 are views illustrating the additive manufacturing process of Example 1. Fig. 7 is a side view showing a molded object produced by the additive manufacturing process of Example 1. The method for manufacturing the orthodontic aligner 20 of Example 1 will be described below.

[0029] (Intraoral data acquisition process) As shown in FIG. 3, in the intraoral data acquisition step (step S10), the inside of the patient's oral cavity is scanned using a three-dimensional scanner to acquire three-dimensional data of the inside of the oral cavity.

[0030] (Digital setup process) In the digital setup process (step S11), the three-dimensional data of the oral cavity acquired in the intraoral data acquisition process is analyzed by a computer, and three-dimensional data of the tooth model 10A at the orthodontic target position is created. For example, if the orthodontic correction is to be performed in stages to the final orthodontic target position, such as in increments of 0.25 mm, three-dimensional data of the tooth model 10A at multiple orthodontic target positions is created.

[0031] (3D data creation process) In the three-dimensional data creation step (step S12), three-dimensional data of the orthodontic aligner 20 is created based on the three-dimensional data of the tooth model 10A at the orthodontic target position created in the digital setup step.

[0032] If necessary, supports may be added to the created 3D data of the orthodontic aligner 20. The shape, thickness, density, angle, presence or absence of branches, etc. of the supports are adjusted appropriately depending on the size, angle, and overhanging parts of the 3D data.

[0033] (Additive manufacturing process) In the additive manufacturing process (step S13), the orthodontic aligner 20 is manufactured by an additive manufacturing device based on the three-dimensional data of the orthodontic aligner 20 created in the three-dimensional data creation process.

[0034] 4, the additive manufacturing apparatus 30 includes a container 32 containing a liquid photocurable resin W, a movable stage 33 configured to be movable up and down within the container 32, and an ultraviolet laser device 31 that irradiates ultraviolet laser light 31a. The photocurable resin W may contain, for example, a polymerizable monomer including a radically polymerizable compound such as a (meth)acrylic monomer, a cationic polymerizable compound such as an epoxy compound, and a photopolymerization initiator.

[0035] The additive manufacturing device 30 configured in this manner is first positioned so that the upper surface of the movable stage 33 is located a predetermined distance (e.g., 0.01 mm) below the liquid surface of the photocurable resin W, as shown in Figure 4.

[0036] Next, the ultraviolet laser device 31 scans the thin layer of photocurable resin W on the movable stage 33 with ultraviolet laser light 31a in a predetermined pattern based on the three-dimensional data of the orthodontic aligner 20. As a result, a first hardened layer (an example of the hardened layer 25) 25a having the outer shape of the tooth 10 is formed.

[0037] 5, the movable stage 33 moves downward by a predetermined distance (for example, 0.01 mm), thereby forming a thin layer of the photocurable resin W on the first cured layer 25a.

[0038] 6, the ultraviolet laser device 31 scans the thin layer of photocurable resin W on the first cured layer 25a with ultraviolet laser light 31a in a predetermined pattern based on the three-dimensional data of the orthodontic aligner 20. This forms a second cured layer (an example of the cured layer 25) 25b having the outline of the tooth 10.

[0039] Thereafter, the same operations are repeated until finally, as shown in FIG. 7, an orthodontic aligner 20 with a support 26 is produced, in which multiple hardened layers 25a, 25b, ..., 25n (25) are stacked at a predetermined stacking pitch (0.01 mm in Example 1).

[0040] The occlusal plane of the orthodontic aligner 20 covering the occlusal surfaces 11 of the teeth 10 is referred to as the occlusal plane S1. The occlusal plane refers to a reference plane defined as a plane including the midpoint (incisal point) between the mesial angles of the left and right central incisors and the distal buccal cusp tips of the left and right first molars. In other words, the occlusal plane S1 is a plane parallel to the arrangement direction of the portions of the orthodontic aligner 20 covering each tooth 10. The vertical plane including the anterior-posterior direction D of the orthodontic aligner 20 is referred to as the vertical plane S2.

[0041] The intersection line between the occlusal plane S1 and the vertical plane S2 is defined as the first intersection line L1. The intersection line between the vertical plane S2 and the horizontal plane S3 is defined as the second intersection line L2. The angle between the first intersection line L1 and the second intersection line L2 is defined as the angle θ. The orthodontic aligner 20 has the cured layers 25 stacked vertically in a position that forms the angle θ.

[0042] (Post-processing process) In the post-processing step (step S14), the supports 26 are removed using a tool such as nippers from the orthodontic aligner 20. After the supports 26 are removed, the marks left by the supports 26 may be polished away.

[0043] In addition, in the post-processing step (step S14), some or all of the unreacted materials, such as unpolymerized monomers, are removed from the manufactured orthodontic aligner 20. The post-processing step may include removing the unreacted materials using gravity or centrifugal force, cleaning with an organic solvent or by air blowing, drying, and photopolymerization or thermal polymerization using an irradiator such as a fluorescent lamp, a halogen lamp, or an LED light source.

[0044] Through the above steps, the orthodontic aligner 20 is manufactured.

[0045] [Orthodontic aligners shaped at various angles] Fig. 8 is a diagram showing the front teeth portion when an orthodontic aligner is shaped at an angle θ = 0°. Fig. 9 is a diagram showing the front teeth portion when an orthodontic aligner is shaped at an angle θ = 30°. Fig. 10 is a diagram showing the front teeth portion when an orthodontic aligner is shaped at an angle θ = 60°. Fig. 11 is a diagram showing the front teeth portion when an orthodontic aligner is shaped at an angle θ = 90°. Orthodontic aligners shaped at various angles will be described below.

[0046] 1, the front tooth portion 24 of the orthodontic aligner 20 that covers the central incisor 10a of the front teeth 14 is referred to as the central incisor portion 20a. The front tooth portion 24 of the orthodontic aligner 20 that covers the lateral incisor 10b of the front teeth 14 is referred to as the lateral incisor portion 20b. The front tooth portion 24 of the orthodontic aligner 20 that covers the canine 10c of the front teeth 14 is referred to as the canine portion 20c.

[0047] (Angle θ=0°) When the angle θ is 0°, an annular layering mark M1 is formed on the upper ends of the central incisor portion 20a and the lateral incisor portion 20b, as shown in Fig. 8. The annular layering mark M1 is completely invisible when the central incisor portion 20a and the lateral incisor portion 20b are viewed from the front. Furthermore, a linear layering mark N1 is formed in a substantially horizontal direction on the buccal side portions 22 of the central incisor portion 20a and the lateral incisor portion 20b.

[0048] When the angle θ=0°, the orthodontic aligner 20 has the cured layer 25 laminated in a direction perpendicular to the occlusal plane S1. Therefore, lamination marks N1 are formed horizontally to the occlusal plane S1 on the buccal portion 22 of the anterior tooth portion 24 of the orthodontic aligner 20. Note that, when the angle θ=180°, lamination marks are formed in the same manner as when the angle θ=0° on the molded object.

[0049] (Angle θ=30°) When the angle θ is 30°, an annular laminated mark M2 is formed on the upper ends of the central incisor portion 20a and the lateral incisor portion 20b, as shown in Fig. 9. The annular laminated mark M2 is almost invisible when the central incisor portion 20a and the lateral incisor portion 20b are viewed from the front. Furthermore, a linear laminated mark N2 is formed in a substantially horizontal direction on the buccal side portions 22 of the central incisor portion 20a and the lateral incisor portion 20b.

[0050] When the angle θ=30°, the orthodontic aligner 20 has the cured layer 25 laminated in a direction inclined at an angle θ=30° with respect to the direction perpendicular to the occlusal plane S1. Note that when the angle θ=150°, angle θ=210°, or angle θ=330°, lamination marks are formed in the same manner as when the angle θ=30°.

[0051] (Angle θ=60°) When the angle θ is 60°, an annular lamination mark M3 is formed at the upper ends of the central incisor portion 20a and the lateral incisor portion 20b, as shown in Fig. 10. When the central incisor portion 20a and the lateral incisor portion 20b are viewed from the front, the annular lamination mark M3 is somewhat visible at the top of the central incisor portion 20a and the lateral incisor portion 20b, but is not noticeable. In addition, a curved lamination mark N3 is formed from the top to the bottom of the buccal portions 22 of the central incisor portion 20a and the lateral incisor portion 20b.

[0052] When the angle θ=60°, the orthodontic aligner 20 has the cured layer 25 laminated in a direction inclined at an angle θ=60° with respect to the direction perpendicular to the occlusal plane S1. Note that when the angle θ=120°, angle θ=240°, or angle θ=300°, lamination marks are formed in the same manner as when the angle θ=60°.

[0053] (Angle θ=90°) When the angle θ is 90°, an annular laminated mark M4 is formed on the buccal surfaces 12 of the central incisor portion 20a and the lateral incisor portion 20b, as shown in Fig. 11. When the central incisor portion 20a and the lateral incisor portion 20b are viewed from the front, the annular laminated mark M4 is clearly visible over the entire buccal surfaces 22 of the central incisor portion 20a and the lateral incisor portion 20b.

[0054] When the angle θ=90°, the orthodontic aligner 20 has the cured layer 25 laminated in a direction inclined at an angle θ=90° with respect to the direction perpendicular to the occlusal plane S1. Note that when the angle θ=270°, the same lamination marks are formed on the molded object as when the angle θ=90°.

[0055] In view of the above, it is preferable that the orthodontic aligner 20 is shaped so that the angle θ is 0 to 60°, 120 to 240°, or 300 to 360°.

[0056] More preferably, the orthodontic aligner 20 is shaped so that the angle θ is 0 to 30°, 150 to 210°, or 330 to 360°.

[0057] That is, the orthodontic aligner 20 is manufactured by laminating a hardened layer 25 on the buccal side portion 22 that covers the buccal surface 12 of the front teeth (central incisor portion 20a, lateral incisor portion 20b, canine portion 20c) so that no annular lamination marks are formed.

[0058] [Operation of orthodontic aligner and manufacturing method for orthodontic aligner] Hereinafter, a description will be given of the operation of the orthodontic aligner and the method for manufacturing the orthodontic aligner of Example 1. The method for manufacturing the mouthpiece (orthodontic aligner 20) of Example 1 is a method for manufacturing a mouthpiece (orthodontic aligner 20) manufactured by an additive manufacturing apparatus 30, which is worn in the oral cavity to cover the teeth 10, and the mouthpiece (orthodontic aligner 20) is manufactured by laminating a hardened layer 25 on the buccal side portion 22 that covers the buccal surfaces 12 of the front teeth (central incisors 10a, lateral incisors 10b, canines 10c) so as not to leave annular lamination marks (FIG. 7).

[0059] This prevents the formation of annular lamination marks on the buccal side portion 22 of the mouthpiece (orthodontic aligner 20) that covers the buccal surfaces 12 of the front teeth (central incisors 10a, lateral incisors 10b, and canines 10c). Therefore, when the mouthpiece (orthodontic aligner 20) is worn in the oral cavity, the annular lamination marks cannot be seen by others. As a result, the aesthetics of the mouthpiece (orthodontic aligner 20) when worn in the oral cavity can be improved.

[0060] Incidentally, when the mouthpiece (orthodontic aligner 20) is formed by stacking hardened layers so that annular lamination marks are formed on the buccal side portion 22 that covers the buccal surfaces 12 of the front teeth (central incisor 10a, lateral incisor 10b, canine 10c) of the mouthpiece (orthodontic aligner 20), a step corresponding to the layer pitch is formed on the buccal side portion 22 where the annular lamination marks are formed. Therefore, when the mouthpiece (orthodontic aligner 20) is worn in the oral cavity, a foreign body sensation becomes noticeable.

[0061] In contrast, in Example 1, the mouthpiece (orthodontic aligner 20) is formed by laminating hardened layers 25 so that no annular lamination marks are formed on the buccal side portion 22 that covers the buccal surfaces 12 of the front teeth (central incisor 10a, lateral incisor 10b, canine 10c). Therefore, the buccal side portion 22 on which the annular lamination marks are formed can have a step that is smaller than the step corresponding to the lamination pitch. As a result, it is possible to suppress the foreign body sensation when the mouthpiece (orthodontic aligner 20) is worn in the oral cavity.

[0062] In the manufacturing method of the mouthpiece (orthodontic aligner 20) of Example 1, the hardened layer 25 is stacked vertically in an orientation such that the angle θ formed by the first intersection line L1 between the occlusal plane S1 of the mouthpiece (orthodontic aligner 20) and the vertical plane S2 including the anterior-posterior direction D, and the second intersection line L2 between the horizontal plane S3 and the vertical plane S2 including the anterior-posterior direction D, is 0 to 60°, 120 to 240°, or 300 to 360° (Figure 10).

[0063] This prevents the formation of annular lamination marks on the buccal side portion 22 of the mouthpiece (orthodontic aligner 20) that covers the buccal surfaces 12 of the front teeth (central incisor 10a, lateral incisor 10b, canine 10c), thereby improving the aesthetics of the mouthpiece (orthodontic aligner 20) when worn in the oral cavity.

[0064] In the manufacturing method of the mouthpiece (orthodontic aligner 20) of Example 1, the hardened layer 25 is stacked vertically in an orientation such that the angle θ formed by the first intersection line L1 between the occlusal plane S1 of the mouthpiece (orthodontic aligner 20) and the vertical plane S2 including the anterior-posterior direction D, and the second intersection line L2 between the horizontal plane S3 and the vertical plane S2 including the anterior-posterior direction D, is 0 to 30°, 150 to 210°, or 330 to 360° (Figure 9).

[0065] This allows for the formation of approximately linear lamination marks on the cheek side portion 22 of the mouthpiece (orthodontic aligner 20) that covers the cheek surfaces 12 of the front teeth (central incisor 10a, lateral incisor 10b, canine 10c), thereby improving the aesthetics of the mouthpiece (orthodontic aligner 20) when worn in the oral cavity.

[0066] The mouthpiece (orthodontic aligner 20) of Example 1 is a mouthpiece (orthodontic aligner 20) that is worn in the oral cavity to cover the teeth 10, and does not have annular layer marks on the buccal side portion 22 that covers the buccal surfaces 12 of the front teeth (central incisors 10a, lateral incisors 10b, canines 10c) (Figures 8 and 9).

[0067] This prevents the formation of annular lamination marks on the buccal side portion 22 of the mouthpiece (orthodontic aligner 20) that covers the buccal surfaces 12 of the front teeth (central incisors 10a, lateral incisors 10b, and canines 10c). Therefore, when the mouthpiece (orthodontic aligner 20) is worn in the oral cavity, the annular lamination marks cannot be seen by others. As a result, the aesthetics of the mouthpiece (orthodontic aligner 20) when worn in the oral cavity can be improved. [Example]

[0068] The mouthpiece and method for manufacturing the mouthpiece of Example 2 differ from the mouthpiece and method for manufacturing the mouthpiece of Example 1 in that the angle θ at which the orthodontic aligner is manufactured in the additive manufacturing process is different.

[0069] [Manufacturing method for orthodontic aligners] 12 is a side view showing a molded object produced by the additive manufacturing process of Example 2. The following describes a method for manufacturing an orthodontic aligner of Example 2. Note that the same terms or the same reference numerals will be used to describe parts that are the same as or equivalent to those described in the above examples.

[0070] (Additive manufacturing process) In the additive manufacturing process, the orthodontic aligner 20 is manufactured by stacking the cured layers 25 at a predetermined layer pitch (0.01 mm in Example 2) in the direction D1 perpendicular to the occlusal plane S1, as shown in FIG. 12. That is, the orthodontic aligner 20 is manufactured by the additive manufacturing device 30, with the stacking direction being the direction D1 perpendicular to the occlusal plane S1. In other words, the orthodontic aligner 20 has layering marks in the direction D1 perpendicular to the occlusal plane S1. That is, in the orthodontic aligner 20, the cured layers 25 are stacked such that the angle θ between the first intersection line L1 and the second intersection line L2 is 0°.

[0071] Note that the same layer marks are formed on the object when the angle θ is 180° as on the object when the angle θ is 0°. The vertical direction D1 is assumed to include an error of approximately 1°.

[0072] The orthodontic aligner 20 has a support 26 formed on the side opposite to the occlusal portion 21, which is the occlusal surface of the orthodontic aligner 20, in a direction D1 perpendicular to the occlusal plane S1.

[0073] [Operation of orthodontic aligner and manufacturing method for orthodontic aligner] 13 is a cross-sectional view of the hardened layer of the orthodontic aligner of Example 2. The effects of the orthodontic aligner of Example 2 and the method for manufacturing the orthodontic aligner will be described below.

[0074] In the method for manufacturing the mouthpiece (orthodontic aligner 20) of Example 2, the mouthpiece (orthodontic aligner 20) is manufactured by laminating the hardened layer 25 in a direction D1 perpendicular to the occlusal plane S1 (FIG. 12).

[0075] This prevents the formation of annular lamination marks on the buccal side portion 22 of the mouthpiece (orthodontic aligner 20) that covers the buccal surfaces 12 of the front teeth (central incisors 10a, lateral incisors 10b, and canines 10c). Therefore, when the mouthpiece (orthodontic aligner 20) is worn in the oral cavity, the annular lamination marks cannot be seen by others. As a result, the aesthetics of the mouthpiece (orthodontic aligner 20) when worn in the oral cavity can be improved.

[0076] 13, the area of ​​the cured layer 25 can be increased. This increases the strength of the mouthpiece (orthodontic aligner 20) in the direction D1 perpendicular to the occlusal plane S1. On the other hand, if layers are stacked horizontally to the occlusal plane S1, the area of ​​each layer becomes smaller, reducing the strength of the mouthpiece in the direction D1 perpendicular to the occlusal plane S1.

[0077] Furthermore, the strength of the object manufactured by the additive manufacturing device 30 is greater in the direction perpendicular to the stacking direction than in the stacking direction. In Example 2, the stacking direction is the direction D1 perpendicular to the occlusal plane S1, so that the tensile strength and compressive strength in the direction horizontal to the occlusal plane S1 can be improved. In other words, in Example 2, the buccal portion 22 of the anterior tooth portion 24 covering the anterior teeth 14 of the teeth 10 can be improved in the tensile strength and compressive strength in the direction horizontal to the occlusal plane S1. Therefore, the strength of the anterior tooth portion 24, which is repeatedly subjected to loads such as bending, stretching, and twisting when putting on and taking off the mouthpiece (orthodontic aligner 20), can be improved.

[0078] Furthermore, the more layers of the object fabricated by the additive manufacturing device 30 are stacked, the higher the compressive strength in the stacking direction can be. Furthermore, because the cured layers 25 are stacked in the direction D1 perpendicular to the occlusal plane S1 of the mouthpiece (orthodontic aligner 20), the buccal side portion 22 can have a larger number of layers than when layers are stacked in any other direction. Therefore, the compressive strength of the buccal side portion 22 can be higher than when layers are stacked in any other direction. As a result, the strength of the buccal side portion 22, which receives a reaction force from the teeth 10 to be corrected during orthodontic treatment using the mouthpiece (orthodontic aligner 20), can be improved, making it less likely for creep deformation to occur in the buccal side portion 22. In other words, deformation of the mouthpiece (orthodontic aligner 20) due to the teeth 10 can be suppressed. As a result, the accuracy of orthodontic treatment of the teeth 10 using the mouthpiece (orthodontic aligner 20) can be improved.

[0079] In the manufacturing method of the mouthpiece (orthodontic aligner 20) of Example 2, the mouthpiece (orthodontic aligner 20) is formed in a grooved shape so as to cover all of the teeth of the upper jaw or the lower jaw (FIG. 2).

[0080] This allows the cured layer 25 to have a closed annular shape as shown in Fig. 13. This allows the strength of the mouthpiece (orthodontic aligner 20) to be increased.

[0081] In the manufacturing method of the mouthpiece (orthodontic aligner 20) of Example 2, a support 26 that supports the mouthpiece (orthodontic aligner 20) is formed on the side opposite the occlusal portion 21 of the mouthpiece (orthodontic aligner 20) in a direction D1 perpendicular to the occlusal plane S1 (Figure 12).

[0082] This prevents marks of the supports 26 from being formed in the occlusal portion 21 when the supports 26 are removed. This prevents stress from concentrating on the occlusal portion 21 due to the marks of the supports 26. As a result, it is possible to improve the durability of the occlusal portion 21, which is subjected to repeated loads.

[0083] The mouthpiece (orthodontic aligner 20) of Example 2 is a mouthpiece (orthodontic aligner 20) that is worn in the oral cavity to cover the teeth 10, and has layer marks in a direction D1 perpendicular to the occlusal plane S1 of the mouthpiece (orthodontic aligner 20) (Figure 12).

[0084] This prevents the formation of annular lamination marks on the buccal side portion 22 of the mouthpiece (orthodontic aligner 20) that covers the buccal surfaces 12 of the front teeth (central incisors 10a, lateral incisors 10b, and canines 10c). Therefore, when the mouthpiece (orthodontic aligner 20) is worn in the oral cavity, the annular lamination marks cannot be seen by others. As a result, the aesthetics of the mouthpiece (orthodontic aligner 20) when worn in the oral cavity can be improved.

[0085] It is also possible to increase the area of ​​the hardened layer 25. This increases the strength of the mouthpiece (orthodontic aligner 20) in the direction D1 perpendicular to the occlusal plane S1.

[0086] The other configurations and effects are substantially the same as those of the above embodiment, and therefore the explanation will be omitted.

[0087] [Evaluation of Aesthetic Satisfaction] In order to confirm the effect of the mouthpiece (orthodontic aligner 20) of the present invention, an evaluation of aesthetic satisfaction was carried out as follows.

[0088] We prepared an orthodontic aligner 20 shaped at an angle θ=0° as shown in Figure 8, an orthodontic aligner 20 shaped at an angle θ=30° as shown in Figure 9, an orthodontic aligner 20 shaped at an angle θ=60° as shown in Figure 10, an orthodontic aligner 20 shaped at an angle θ=90° as shown in Figure 11, and an orthodontic aligner 20 shaped in such a way that the stacking direction D2 as shown in Figure 14 is in the width direction perpendicular to the front-to-back direction D.

[0089] Five subjects were shown each orthodontic aligner 20 while wearing it, and were asked to rate the following three items on a five-point scale: "I don't think so at all = 4 points," "I don't think so much = 3 points," "I think so somewhat = 2 points," "I think so strongly = 1 point," and "I think so very strongly = 0 point." - Layer gap: unevenness is noticeable Transparency: Low transparency Unnaturalness: Feels strange and like "not a natural tooth"

[0090] The average value was calculated for each item, and aesthetics was evaluated as good when the average value exceeded 2.

[0091] [Table 1]

[0092] The orthodontic aligner 20 shaped at an angle θ = 0° had a layering step of 3.6, a transparency of 3.2, and an unnaturalness of 3.6. The orthodontic aligner 20 shaped at an angle θ = 30° had a layering step of 3.6, a transparency of 3.8, and an unnaturalness of 3.8. The orthodontic aligner 20 shaped at an angle θ = 60° had a layering step of 2.8, a transparency of 3.4, and an unnaturalness of 3.2. The orthodontic aligner 20 shaped at an angle θ = 90° had a layering step of 1.6, a transparency of 1.2, and an unnaturalness of 1.2. The orthodontic aligner 20 shaped with the layering direction D2 in the width direction perpendicular to the anterior-posterior direction D had a layering step of 3.2, a transparency of 3.8, and an unnaturalness of 3.2.

[0093] From the above, when the angle θ=0°, the angle θ=30°, and the angle θ=60°, good evaluations were obtained for each item. Furthermore, when the angle θ=0° and the angle θ=30°, even better evaluations were obtained for each item. Furthermore, when the stacking direction D2 was molded in the width direction perpendicular to the front-to-back direction D, good evaluations were obtained for each item. On the other hand, when the angle θ=90°, good evaluations were not obtained for each item.

[0094] The mouthpiece and method for manufacturing the mouthpiece of the present invention have been described above based on Examples 1 and 2. However, the specific configuration is not limited to these Examples, and design changes and additions are permitted as long as they do not deviate from the gist of the invention according to each claim in the scope of the claims.

[0095] In Examples 1 and 2, examples have been shown in which the cured layers 25 are laminated in the vertical direction in a position in which the angle θ between the first intersection line L1 and the second intersection line L2 is 0 to 60°, 120 to 240°, or 300 to 360°. However, as shown in Fig. 14, the lamination direction D2 may be the width direction perpendicular to the anterior-posterior direction D. Furthermore, the lamination direction may be inclined with respect to the width direction perpendicular to the anterior-posterior direction D. This makes it possible to form vertical lamination marks on the buccal side portions covering the buccal surfaces of the anterior teeth, thereby improving aesthetics.

[0096] In Examples 1 and 2, a suspended-type optical modeling device using a photocurable resin that is cured by ultraviolet light is shown as an example of the additive manufacturing device 30. However, the additive manufacturing device may be a suspended-type optical modeling device using a photocurable resin, a projection-type device that uses light from a projector to cure and laminate photocurable resin, an inkjet-type device that sprays liquid ultraviolet curable resin and cures and laminates it by irradiating it with ultraviolet light, a fused deposition modeling method that builds up heat-melting resin layer by layer, or a powder sintering method that sinters powdered material by applying a high-power laser beam.

[0097] In Examples 1 and 2, the orthodontic aligner 20 is formed in a groove shape that covers the crown of the tooth. However, the orthodontic aligner may be shaped to cover the crown and gum, or the crown and tooth base.

[0098] In Examples 1 and 2, the orthodontic aligner 20 is formed in a concave groove shape so as to cover the crowns of all the lower jaw teeth 10. However, the orthodontic aligner may be formed in a concave groove shape so as to cover the crowns of only some of the teeth.

[0099] In Examples 1 and 2, the present invention is applied to an orthodontic aligner 20 attached to the crowns of the lower jaw. However, the present invention can also be applied to an orthodontic aligner attached to the crowns of the upper jaw.

[0100] In Examples 1 and 2, the present invention is applied to an orthodontic aligner 20 that is worn in the oral cavity to cover the teeth 10. However, the present invention is not limited to orthodontic aligners, and can also be applied to mouthpieces for preventing teeth grinding, mouthpieces for treating temporomandibular joint disorders and sleep apnea syndrome, mouthpieces for whitening, mouthpieces for indirect bonding, and mouthpieces for sports. The mouthpiece of the present invention also includes devices that are worn to cover the teeth.

[0101] This application claims priority based on Japanese Patent Application No. 2019-109886 filed with the Japan Patent Office on June 12, 2019, and Japanese Patent Application No. 2019-109887 filed with the Japan Patent Office on June 12, 2019, the entire disclosures of which are incorporated herein by reference in their entirety.

Claims

1. A method for manufacturing a mouthpiece that is manufactured using an additive manufacturing apparatus and is worn in the oral cavity to cover the teeth, comprising: The mouthpiece is manufactured by laminating a hardened layer on a cheek side portion covering the cheek surfaces of the front teeth so as not to form an annular lamination mark, A first intersection line between the occlusal plane of the mouthpiece and a vertical plane including the front-to-back direction; The angle between the horizontal plane and the second intersection line with the vertical plane including the front-to-back direction is In a position where the angle is 30°, 60°, 120-150°, 210-240°, or 300-330°, The hardened layers are stacked vertically. A method for manufacturing a mouthpiece, comprising:

2. A first intersection line between the occlusal plane of the mouthpiece and a vertical plane including the front-to-back direction; The angle between the horizontal plane and the second intersection line with the vertical plane including the front-to-back direction is In a position where the angle is 30°, 150°, 210°, or 330°, The hardened layers are stacked vertically. A method for manufacturing the mouthpiece according to claim 1.

3. The hardened layer is manufactured by laminating in a direction inclined by 30° or 60° with respect to a direction perpendicular to the occlusal plane of the mouthpiece. A method for manufacturing the mouthpiece according to claim 1.

4. The mouthpiece is formed in a concave groove shape so as to cover all of the upper or lower jaw teeth. A method for manufacturing the mouthpiece according to any one of claims 1 to 3.

5. The mouthpiece has a support formed on the opposite side of the occlusal portion of the mouthpiece in a direction perpendicular to the occlusal plane, the support supporting the mouthpiece being formed on the opposite side of the occlusal portion of the mouthpiece, It is formed in a groove shape to cover all of the upper or lower jaw teeth. The method for manufacturing the mouthpiece according to claim 3.

6. A method for manufacturing a mouthpiece that is manufactured using an additive manufacturing apparatus and is worn in the oral cavity to cover the teeth, comprising: The mouthpiece is manufactured such that vertical lamination marks are formed on the cheek side portion covering the cheek surfaces of the front teeth, and the hardened layer is laminated in a width direction perpendicular to the front-to-back direction of the mouthpiece or in a direction inclined relative to the width direction perpendicular to the front-to-back direction so as not to form annular lamination marks. A method for manufacturing a mouthpiece, comprising:

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