METHOD FOR CREATING IMAGE DATA OF DENTAL SHAPED OBJECT, APPARATUS FOR CREATING IMAGE DATA OF DENTAL SHAPED OBJECT, PROGRAM FOR CREATING IMAGE DATA OF DENTAL SHAPED OBJECT, METHOD FOR MANUFACTURING DENTAL SHAPED OBJECT, AND DENTAL SHAPED OBJECT

A method for creating image data of a dental shaped object has steps of: acquiring image data of a dental shaped object having a side-wall portion forming a horseshoe-shaped concave portion; creating image data of a reinforcing member that reinforces the side-wall portion in CAD; and connecting the image data of the dental shaped object and the image data of the reinforcing member.

TECHNICAL FIELD

The present disclosure relates to a method for creating image data of a dental shaped object, an apparatus for creating image data of a dental shaped object, a program for creating image data of a dental shaped object, a method for manufacturing a dental shaped object, and a dental shaped object.

BACKGROUND ART

In recent years, a technique of shaping a dental shaped object such as a denture base, a mouthpiece, or a dental model with a stereolithography type 3D printer has been proposed. Here, the “dental shaped object” is a shaped object having a shape that can be fitted to an alveolar ridge of a patient and used mainly in therapeutic, research, educational, and other situations in the dental field.

For example, in a suspended stereolithography type 3D printer, an ultraviolet (UV light) curable resin liquid accumulated in a liquid tank is irradiated with UV light based on cross-sectional data of a shape to be formed, thereby shaping a thin cured layer of resin. A build table is arranged on an upper side of the liquid tank, and the denture base is suspended from the build table by a support pin. A process of sequentially disposing new layers one by one on the cured layer while gradually raising the build table is repeated, thereby finally shaping a desired denture base.

Manufacturing data used as cross-sectional data in such a stereolithography type 3D printer can be created using, for example, a CAD/CAM (Computer Aided Design and Computer Aided Manufacturing) system as described in Patent Literature 1. By introducing the CAD/CAM system and the stereolithography type 3D printer for the shaping work of the dental shaped object, it is possible to obtain an advantage of being able to improve the efficiency of the work and suppress the variation in quality.Patent Literature 1: WO 2010/058822 A

SUMMARY OF INVENTION

Technical Problem

Here, in the additive manufacturing using the stereolithography type 3D printer that disposes thin cured layers one on another as a shaping device, there are cases, for example, in which the cured layer cannot be disposed depending on the shape of the object to be formed, such as in the case of an overhang shape, and in which the cured layer to be disposed one on another is suspended under the build table. In the case of such shaping, a method that extends the support material from the build table and supporting the object being shaped from the outside of the object is adopted.

However, when the dental shaped object is, for example, a denture base in which a horseshoe-shaped (that is, U-shaped) concave portion into which gums of the alveolar ridge are fitted is formed, a side-wall portion forming the concave portion may be inclined even if the denture base is supported by the support material, and thus a groove width of the concave portion may become larger than a design value. The inclination of the side-wall portion is attributed to gravity applied to the object to be shaped during shaping and shrinkage of resin when solidified by cooling. As a result, inconvenience such as a wobbly denture base may occur when the shaped denture base is attached to the gums of the patient.

To improve this inconvenience, it is also conceivable to create image data for forming a reinforcing member that reinforces the side-wall portion of the denture base using CAM, which transmits slice data serving as cross-sectional data to the 3D printer. However, CAM is originally a software system used to perform overall production preparation for a 3D printer on a computer using image data created in CAD as input data. For this reason, it is difficult to appropriately create the image data for forming the reinforcing member using CAM, which reduces the shaping accuracy and requires a lot of time and effort. In addition, since an operator who operates the CAM system is not necessarily a designer of the denture base, there is a high probability that appropriate data cannot be created when the CAM operator creates data of the reinforcing member that reinforces the denture base, which results in the shaping accuracy of the denture base shaped by the 3D printer becoming unstable.

The disclosure has been made in view of this problem, and provides a method for creating image data of a dental shaped object, an apparatus for creating image data of a dental shaped object, a program for creating image data of a dental shaped object, a method for manufacturing a dental shaped object using the method for creating image data of a dental shaped object, and a dental shaped object, which make it possible to form image data of a reinforcing member that reinforces a denture base with favorable shaping accuracy and excellent stability of shaping accuracy, and in a simple manner.

Solution to Problem

Means for solving the problem includes the following aspects.

<1> A method for creating image data of a dental shaped object, the method including steps of: acquiring image data of a dental shaped object having a side-wall portion forming a horseshoe-shaped concave portion; creating image data of a reinforcing member that reinforces the side-wall portion in CAD; and connecting the image data of the dental shaped object and the image data of the reinforcing member.

<2> The method for creating image data of a dental shaped object according to <1>, in which the reinforcing member is one rod-shaped member connecting left and right portions of the side-wall portion.

<3> The method for creating image data of a dental shaped object according to <2> above, in which the rod-shaped member connects the back side end portions of the left and right portions of the side-wall portion in an oral cavity.

<4> The method for creating image data of a dental shaped object according to <2> or <3> above, in which the reinforcing member includes a rod-shaped member that connects front surfaces of left and right portions of the inner side-wall portion in a dental shaped object for a mandibular.

<5> The method for creating image data of a dental shaped object according to <4> above, in which the rod-shaped member connects the lower ends of the left and right portions of the inner side-wall portion.

<6> The method for creating image data of a dental shaped object according to <2> or <3> above, in which the reinforcing member has a rod-shaped member that connects back surfaces of left and right portions of the outer side-wall portion in a dental shaped object for a maxilla.

<7> The method for creating image data of a dental shaped object according to <6> above, in which the rod-shaped member connects the upper ends of the left and right portions of the outer side-wall portion.

<8> The method for creating image data of the dental shaped object according to <6> or <7> above, in which the reinforcing member further has a rod-shaped member that connects the front surfaces of the left and right portions of the inner side-wall portion in the dental shaped object for a maxilla.

<9> The method for creating image data of a dental shaped object according to any one of <1> to <8> above, in which the dental shaped object is a denture base fitted to an alveolar ridge of a patient.

<10> A method for manufacturing a dental shaped object, the method including steps of: creating, in CAD, image data for design of a dental shaped object in which a reinforcing member is formed according to the method for creating image data of a dental shaped object according to any one of <1> to <9> above; creating image data for manufacturing using the image data for design; and shaping a dental shaped object with a 3D printer using the image data for manufacturing.

<11> A dental shaped object having a side-wall portion forming a horseshoe-shaped concave portion, the dental shaped object having a connection mark of a reinforcing member that reinforces left and right portions of the side-wall portion at back side end portions of the side-wall portion in the oral cavity.

<12> An apparatus for creating image data of a dental shaped object, the apparatus including an arithmetic device having: an image data acquisition unit that acquires image data of a dental shaped object having a side-wall portion forming a horseshoe-shaped concave portion; and an image data creation unit that creates image data of a reinforcing member that reinforces the side-wall portion in CAD and connects the image data of the dental shaped object and the image data of the reinforcing member.

<13> A program for creating image data of a dental shaped object, the program being configured to cause a computer to execute processing including steps of: causing an image data acquisition unit to acquire image data of a dental shaped object having a side-wall portion forming a horseshoe-shaped concave portion; and causing an image data creation unit to create image data of a reinforcing member that reinforces the side-wall portion in CAD, and to connect the image data of the reinforcing member to the image data of the dental shaped object.

Advantageous Effects of Invention

According to the disclosure, it is possible to provide a method for creating image data of a dental shaped object, an apparatus for creating image data of a dental shaped object, a program for creating image data of a dental shaped object, a method for manufacturing a dental shaped object using the method for creating image data of a dental shaped object, and a dental shaped object, which make it possible to form image data of a reinforcing member that reinforces a denture base with favorable shaping accuracy and excellent stability of shaping accuracy, and in a simple manner.

DESCRIPTION OF EMBODIMENTS

Embodiments of the present disclosure will be described below. In the following description of the drawings, the same reference numerals or similar reference numerals are assigned to the same portions and similar portions. However, the drawings are schematic, and the relationship between the thickness and the plane dimension, the ratio of the thickness of each device and each member, and the like are different from actual ones. Therefore, specific thicknesses and dimensions should be determined in consideration of the following description. In addition, the drawings include portions having different dimensional relationships and ratios.

—Method for Creating Image Data—

First, a mandibular denture base10and a maxillary denture base20will be described with reference toFIGS.1and2. A method for creating image data of a dental shaped object according to the present embodiment is a method for creating image data of the mandibular denture base10having a reinforcing member18shown inFIG.1and the maxillary denture base20having a reinforcing member28shown inFIG.2. Note that the dental shaped object is not limited to the denture base, and may be another shaped object such as a mouthpiece such as a splint and a mouthguard, or a dental model. In addition, examples of the dental model include, for example, a denture base for display that is not fitted to an alveolar ridge of a patient.

As shown inFIG.1, the mandibular denture base10is a dental shaped object made of resin such as resin including a top portion12, an inner side-wall portion14, and an outer side-wall portion16, in which the reinforcing member18is integrally formed.

The mandibular denture base10inFIG.1is placed on a horizontal plane, and a central axis A inFIG.1overlaps the midline in an oral cavity. In the embodiment, an upper left side inFIG.1, which is a lip side along the central axis A, is defined as a “front side”, and a lower right side inFIG.1, which is a throat side along the central axis A, is defined as a “back side”. Unless otherwise specified, the terms “upper side” and “lower side” herein mean the vertical direction in a state in which the mandibular denture base10is fitted to the mandibular alveolar ridge as shown inFIG.1.

A surface located on the mandibular alveolar ridge side when the mandibular denture base10is fitted and provided with a concave portion10A is defined as a “back surface”. A surface located on a side opposite to the mandibular alveolar ridge when the mandibular denture base10is fitted, and provided with a plurality of depressions10B in which artificial teeth (not shown) are embedded is defined as a “front surface”. That is,FIG.1is a perspective view of the mandibular denture base10viewed from the front surface side on the upper side. In addition, unless otherwise specified, the term “inner side” means a side closer to the central axis A than the top portion12(that is, the lingual side) in a plan view in which the front surface of the top portion12is viewed from the front (seeFIGS.9and11), and the term “outer side” means a side farther from the central axis A than the top portion12(that is, the buccal side).

The top portion12is a horseshoe-shaped (that is, U-shaped) plate-like member in plan view. The inner side-wall portion14is a plate-like member provided in a U-shaped inner edge portion of the top portion12so as to descend from the top portion12. The outer side-wall portion16is a plate-like member provided in a U-shaped outer edge portion of the top portion12so as to descend from the top portion12.

The mandibular denture base10has a horseshoe-shaped (that is, U-shaped) concave portion10A surrounded by the top portion12, the inner side-wall portion14, and the outer side-wall portion16, and the mandibular alveolar ridge is fitted to the concave portion10A. The back surface of the top portion12is a portion covering an upper surface of the mandibular alveolar ridge. The back surface of the inner side-wall portion14is a portion covering the inner side-wall surface of the mandibular alveolar ridge on the lingual side. The back surface of the outer side-wall portion16is a portion covering the outer side-wall surface of the mandibular alveolar ridge on the buccal mucosa side.

In the top portion12, a plurality of depressions10B are formed from the front side to the back side (that is, the rear side). In the embodiment, seven depressions10B corresponding to seven artificial teeth from central incisors located on the front side to second molars located on the rear side are formed across the central axis A. However, the disclosure is not limited thereto, and the number of depressions10B can be arbitrarily set. In the mandibular denture base10, an end portion17of the main body located on a further back side from the depression for the second molar is an end portion of a region corresponding to a retromolar pad of the mandibular alveolar ridge.

The reinforcing member18of the mandibular denture base10reinforces the side-wall portion of the concave portion10A. In the embodiment, the reinforcing member18is one rod-shaped member that connects the lower ends of the front surfaces of the left and right portions of the inner side-wall portion14of the concave portion10A. The rod-shaped member of the reinforcing member18connects the end portions17of the left and right portions of the inner side-wall portion14of the concave portion10A on the back side in the oral cavity and intersects with the central axis A.

Note that the reinforcing member18in the mandibular is removed after shaping, but is not limited to a rod-shaped object, and any other shape such as a plate shape or an arch shape can be adopted as long as it can reinforce the side-wall portion of the concave portion10A and is removable. In the embodiment, the reinforcing member18is one rod-shaped member and thus can be easily designed and manufactured. In addition, the number of reinforcing members18may be arbitrarily set to one or more.

In the disclosure, the connection position of the reinforcing member can be appropriately changed. In the inner side-wall portion14and the outer side-wall portion16, the end portion17located on the back side along the central axis A is a portion where the interval between the inner side-wall portion14and the outer side-wall portion16adjacent to each other across the concave portion10A is the largest, and thus is most easily deformed at the time of shaping due to its structural characteristics. For this reason, when one rod-shaped member is used as the reinforcing member, it is preferable that the reinforcing member connect the end portions17, which are the back side end portions of the left and right portions of the inner side-wall portion14.

Furthermore, in the mandibular denture base10, the lower ends of the inner side-wall portion14and the outer side-wall portion16are located the farthest from the top portion12along the vertical direction. The top portion12connects the inner side-wall portion14and the outer side-wall portion16adjacent to each other across the concave portion10A. For this reason, the deformation amount of the lower ends is particularly large, and thus it is preferable that the reinforcing member connect the lower ends of the left and right portions of the inner side-wall portion14when one rod-shaped member is used as the reinforcing member. In the embodiment, the reinforcing member18connects the lower ends of the end portions17that are the back side end portions on the front surfaces of the left and right portions of the inner side-wall portion14.

As shown inFIG.2, the maxillary denture base20is a dental shaped object made of resin such as resin including a bottom portion22, an inner side-wall portion24, and an outer side-wall portion26, in which the reinforcing member28is integrally formed.

The maxillary denture base20inFIG.2is placed on the horizontal plane, and a central axis B inFIG.2overlaps the midline in the oral cavity. In the embodiment, a lip side along the central axis B (an upper left side inFIG.2) is defined as a “front side”, and a throat side along the central axis B (a lower right side inFIG.2) is defined as a “back side”. Unless otherwise specified, the terms “upper side” and “lower side” in the maxillary denture base20herein mean the vertical direction in a state in which the maxillary denture base20is fitted to a maxillary alveolar ridge as shown inFIG.2.

A surface located on the maxillary alveolar ridge side when the maxillary denture base20is fitted and provided with a concave portion20A is defined as a “back surface”. A surface located on a side opposite to the maxillary alveolar ridge when the maxillary denture base20is fitted, and provided with a plurality of depressions20B (seeFIGS.12A and12B) in which artificial teeth (not shown) are embedded is defined as a “front surface”. That is,FIG.2is a perspective view of the maxillary denture base20viewed from the back surface side on the upper side. In addition, unless otherwise specified, the term “inner side” in the maxillary denture base20means a side closer to the central axis B than the bottom portion22(lingual side) in a plan view in which the back surface of the bottom portion22is viewed from the front (seeFIG.12), and the term “outer side” means a side farther from the central axis B than the bottom portion22(buccal side).

The bottom portion22is a horseshoe-shaped (that is, U-shaped) plate-like member in plan view. The inner side-wall portion24is a plate-like member provided in a U-shaped inner edge portion of the bottom portion22so as to descend from the bottom portion22. The outer side-wall portion26is a plate-like member provided in a U-shaped outer edge portion of the bottom portion22so as to descend from the bottom portion22.

The maxillary denture base20has a horseshoe-shaped (that is, U-shaped) concave portion20A surrounded by the bottom portion22, the inner side-wall portion24, and the outer side-wall portion26, and the maxillary alveolar ridge is fitted to the concave portion20A. The back surface of the bottom portion22is a portion covering a lower surface of the maxillary alveolar ridge. The back surface of the inner side-wall portion24is a portion covering the inner side-wall surface of the maxillary alveolar ridge on the inner side and the palatine mucosa. The back surface of the outer side-wall portion26is a portion covering the outer side-wall surface of the maxillary alveolar ridge on the buccal mucosa side.

In the bottom portion22, a plurality of depressions20B (seeFIGS.12A and12B) are formed from the front side to the back side. The number of depressions20B can be arbitrarily set, as in the case of the mandibular denture base. As in the case of the mandibular denture base, in the maxillary denture base20, an end portion27of the main body is an end portion of a region on a further back side from the depression of the second molar.

The reinforcing member28of the maxillary denture base20reinforces the side-wall portion of the concave portion20A. In the embodiment, the reinforcing member28is one rod-shaped member that connects the upper ends of the back surfaces of the left and right portions of the inner side-wall portion24of the concave portion20A. The rod-shaped member of the reinforcing member28connects the end portions27of the left and right portions of the outer side-wall portion26of the concave portion20A on the back side in the oral cavity and intersects with the central axis B. The meaning of the “rod-shaped member” in the maxilla is the same as that in the mandibular. Note that the reinforcing member28in the maxilla is removed after shaping, as in the case of the mandibular, but is not limited to a rod-shaped object, and any other shape such as a plate shape or an arch shape can be adopted as long as it can reinforce the side-wall portion of the concave portion20A and is removable. In the embodiment, since the reinforcing member28is one linear rod-shaped member, it can be easily designed and manufactured. In addition, the number of reinforcing members28may be arbitrarily set to one or more.

In the disclosure, the connection position of the reinforcing member can be appropriately changed. In the inner side-wall portion24and the outer side-wall portion26, the end portion27located on the back side along the central axis B is a portion where the interval between the inner side-wall portion24and the outer side-wall portion26adjacent to each other across the concave portion20A is the largest, and thus is most easily deformed at the time of shaping due to its structural characteristics. For this reason, when one rod-shaped member is used as the reinforcing member, it is preferable that the reinforcing member connect the end portions27, which are the left and right back side end portions.

Furthermore, in the maxillary denture base20, the upper end of the outer side-wall portion26is located the farthest from the top portion12upward along the vertical direction. The top portion12connects the inner side-wall portion24and the outer side-wall portion26adjacent to each other across the concave portion20A. For this reason, the deformation amount of the upper ends is particularly large, and thus it is preferable that the reinforcing member connect the upper ends of the left and right portions of the outer side-wall portion26when one rod-shaped member is used as the reinforcing member. In the embodiment, the reinforcing member28connects the upper ends of the end portions27, which are the back side end portions on the back surfaces of the left and right portions of the outer side-wall portion26.

—Method for Manufacturing Dental Shaped Object—

Next, a manufacturing device of a dental shaped object and a method for manufacturing a dental shaped object using the manufacturing device according to the embodiment will be described with reference toFIGS.3to8. As shown inFIG.3, the manufacturing device of a dental shaped object according to the embodiment has an image data acquisition device30, a design image data creation device40, a manufacturing image data creation device50, and a shaping device60.

The image data acquisition device30is, for example, a 3D scanner, and is connected to the design image data creation device40. The image data acquisition device30scans, for example, an impression object reflecting a shape of a mandibular alveolar ridge of a patient (hereinafter referred to as a “mandibular impression object”) or a mandibular denture base actually used by the patient and not including the reinforcing member, and acquires image data indicating a three-dimensional (3D) shape of the main body of the mandibular denture base. Alternatively, the mandibular alveolar ridge is directly scanned from the oral cavity of the patient to acquire image data indicating the three-dimensional (3D) shape of the mandibular alveolar ridge. The acquired image data is input to the design image data creation device40. Note that, in the disclosure, the image data acquisition device30is not essential, and for example, 3D shape data created by arbitrary software and prepared in advance may be input to the design image data creation device40.

Although the method for manufacturing a dental shaped object in the case of the mandibular alveolar ridge is exemplarily described in the embodiment, the disclosure is not limited thereto. In the disclosure, as in the case of the mandibular alveolar ridge, image data of the maxillary denture base or the like can be acquired also in the case of manufacturing a dental shaped object having a horseshoe shape such as the maxillary alveolar ridge, based on, for example, an impression object reflecting the shape of the maxillary alveolar ridge of the patient (that is, a maxillary impression object), a horseshoe-shaped dental shaped object such as the maxillary denture base that is actually used, or the shape of the maxillary alveolar ridge or the like directly scanned from the oral cavity of the patient. The horseshoe-shaped dental shaped object is, for example, a denture base, a mouthpiece, a splint, or the like.

(Design Image Data Creation Device)

As the design image data creation device40of the embodiment, for example, a general-purpose personal computer or the like including a central integrated circuit (CPU), a storage device, an input device, and a display device (that is, an output device), all of which are not shown, can be used. The design image data creation device40has a 3D-CAD function as an image processing program for processing image data. The design image data creation device40corresponds to an “apparatus for creating image data” of the disclosure. The manufacturing image data creation device50is connected to the design image data creation device40.

As shown inFIG.4, the design image data creation device40includes an arithmetic device42including an image data acquisition unit42A and an image data creation unit42B. In step S10inFIG.5, the image data acquisition unit42A acquires, for example, image data of the mandibular alveolar ridge, the mandibular impression object, or the main body of the mandibular denture base from the image data acquisition device30. The image data creation unit42B is a region that performs the 3D-CAD function, and processes the image data of the mandibular alveolar ridge, the mandibular impression object, or the main body of the mandibular denture base acquired by the image data acquisition device30into a shape suitable for use as an actual dental shaped object to create image data of the dental shaped object. The processing of the image data includes, for example, deletion of a shape of an unnecessary portion included in a scan image immediately after scanning and integration of image data in a case in which a plurality of pieces of image data are acquired.

In step S10inFIG.5, in a case in which the image data of the main body of the mandibular denture base acquired from the image data acquisition device30is used, the image data of the main body of the mandibular denture base acquired without processing may be used as it is as the image data of the dental shaped object. In addition, in step S20inFIG.5, the image data creation unit42B creates reinforcing member data118that is image data of the reinforcing member. Furthermore, in step S30inFIG.5, the image data creation unit42B connects the image data of the dental shaped object and the reinforcing member data118as data constituting single data indicating the shape of one mandibular denture base by associating each data with the single data. Image data100for design is created by the connection.

That is, in the image data100for design after the connection, the image data of the dental shaped object and the reinforcing member data118are integrated. For example, when the image data100for design is selected by clicking or the like in the virtual 3D coordinate space, the image data of the dental shaped object and the reinforcing member data118can be integrally moved without separating the image data of the dental shaped object and the reinforcing member data118.

The method for creating image data according to the embodiment is performed by 3D-CAD of the design image data creation device40. Specifically, for example, a designer can move, arrange, and rotate the image data of the dental shaped object to an arbitrary position in the virtual 3D coordinate space on the display of the design image data creation device40. In addition, the shape of the reinforcing member data118can be created using one or more features, and the created reinforcing member data118can be moved to and superimposed on the image data of the dental shaped object in the 3D coordinate space, they can be connected to each other at a predetermined position.

Here, CAD is more advantageous in design work than CAM. For example, CAD usually has more types of adoptable features than CAM. In addition, the degree of flexibility of movement and rotation of the reinforcing member data118is higher in CAD than in CAM. Furthermore, it is also easy in CAD to partially change the shape of the image data of the dental shaped object or the reinforcing member data118while maintaining the connection state between the image data of the dental shaped object and the reinforcing member data118. For these reasons, using CAD makes it possible to efficiently and accurately create the image data100for design.

Although a case in which the processing of step S10and step S20inFIG.5is performed by a human operating the image data acquisition device30and the design image data creation device40has been exemplified in the method for creating image data according to the embodiment, the disclosure is not limited thereto. For example, an image data creation program that causes a computer to execute the processing of steps S10and S20may be created. Then, the image data acquisition device30and the design image data creation device40may be caused to execute the processing of step S10and step S20by the created image data creation program to create the image data100for design.

In addition, the image data of the dental shaped object in step S10may be acquired by processing the image data of the mandibular alveolar ridge, the mandibular impression object, or the mandibular denture base acquired by the image data acquisition device as described above. However, in the disclosure, for example, image data of a dental shaped object of a previously existing mandibular denture base may be read into the 3D scanner or the like for acquisition. In addition, the acquired image data may be directly connected to the reinforcing member data118as it is without being processed to create the image data100for design.

Inside the display device of the design image data creation device40inFIG.3, image data100for design of the mandibular denture base created in CAD is illustrated. The image data100for design has, as data regions in a virtual 3D coordinate space, a top portion region112corresponding to the top portion of the actual mandibular denture base, an inner side-wall portion region114corresponding to the inner side-wall portion, and an outer side-wall portion region116corresponding to the outer side-wall portion. In addition, reinforcing member data118is arranged between the left and right inner side-wall portion regions114. The image data100for design is input to the manufacturing image data creation device50.

(Manufacturing Image Data Creation Device)

As in the design image data creation device40, the manufacturing image data creation device50is a computer including a central integrated circuit (not shown), a storage device, an input/output device, and the like, and has a CAM function. The manufacturing image data creation device50is connected to the shaping device60. In step S40inFIG.5, the manufacturing image data creation device50processes the image data100for design in a virtual 3D coordinate space, and creates the image data100A for manufacturing to be used for shaping by the shaping device60. Specifically, shaping conditions such as an arrangement angle and a distance of the mandibular denture base with respect to the build table of the shaping device60are set, and the set shaping conditions are reflected in the image data100A for manufacturing by CAM. In addition, data of a support pin for shaping is created by CAM.

As shown inFIG.6, the image data100A for manufacturing processed in CAM is suspended by a plurality of support pin regions170corresponding to the support pins from a build table region166corresponding to the build table as a data region in the virtual 3D coordinate space. Reinforcing member data118is exposed between the plurality of support pin regions170. The image data100A for manufacturing is input to the shaping device60.

As shown inFIG.3, the shaping device60is a suspended type 3D printer, and shapes a dental shaped object by vat photopolymerization. The shaping device60includes a liquid tank62that stores a photocurable liquid resin64, a build table66serving as a foundation of the dental shaped object, and a suspension member68that suspends the build table66. InFIG.3, a light irradiator69that irradiates a lower surface of the build table66with light is provided under the liquid tank62.

Although the shaping device60of the embodiment is a suspended type, the disclosure is not limited thereto. In addition, although DLP (Digital Light Processing) type stereolithography has been exemplified in the embodiment, the disclosure is not limited thereto, and for example, other shaping methods such as SLA (Stereolithography) type stereolithography, LCD (Liquid Crystal Display) type stereolithography, or inkjet type stereolithography may be adopted.

The light irradiator69selectively irradiates a lower side of the build table66immersed in the liquid tank62with light of a predetermined wavelength such as ultraviolet light based on the image data100A for manufacturing input to the shaping device60. With light irradiation, the liquid resin64is photopolymerized and selectively cured in a formation region63having a constant thickness, and a resin layer of the object to be shaped is formed. Then, as the suspension member68moves upward inFIG.1, the build table66rises by the set thickness of the resin layer.

By selectively emitting light using the light irradiator69, a stacked state of a subsequent resin layer is formed under the previously formed resin layer.FIG.3illustrates a state in which a part of the mandibular denture base10being shaped is suspended by the support pin70extending from the lower surface of the build table66. Rising of the build table66and light irradiation are repeated in step S50inFIG.5, thereby finally forming the mandibular denture base10having the reinforcing member18as shown inFIG.1.

Next, the reinforcing member18is cut off from the shaped mandibular denture base10, and burrs and the like at the connection portion of the main body are removed. Then, a surface of the mandibular denture base10undergoes predetermined treatment such as polishing, whereby the mandibular denture base serving as the dental shaped object according to the embodiment that can be fitted to the mandibular alveolar ridge of the patient can be obtained.FIG.7illustrates the mandibular denture base10in which connection marks19of the reinforcing member18are formed on outer surfaces of the left and right portions of the inner side-wall portion14of the concave portion10A after the reinforcing member18is removed.FIG.8illustrates the maxillary denture base20in which a connection mark29of the reinforcing member28is formed on an inner surface of the left and right portions of the outer side-wall portion26of the concave portion20A after the reinforcing member28is removed.

In the disclosure, the connection mark may remain as it is on a surface of the denture base in a state in which the denture base is actually fitted to the alveolar ridge, or may undergo surface treatment so that it become inconspicuous. The shape of the connection mark remaining and appearing on the surface is arbitrary according to the shape of the connection portion of the reinforcing member. In a case in which the connection mark is inconspicuous on the surface of the denture base, it can be determined whether or not the reinforcing member was provided, for example, based on a difference in properties between resin from the connection portion of the reinforcing member and resin from around the connection portion by peeling off the surface by about several microns and observing resin of the peeled portion with a microscope.

In the mandibular denture base10, since it is preferable to connect the end portions17, which are back side end portions that are easily deformed in the inner side-wall portion14and the outer side-wall portion16, it is preferable that the connection marks be formed on the left and right end portions17. Furthermore, since the lower ends of the inner side-wall portion14and the outer side-wall portion16are regions where the deformation amount becomes large, it is preferable that the connection marks be formed on the lower ends of the left and right portions of the inner side-wall portion14. In the embodiment, the connection marks19are formed on the lower ends of the end portions17at the front and back surfaces of the left and right portions of the inner side-wall portion14.

In the maxillary denture base20, since it is preferable to connect the end portions27, which are back side end portions that are easily deformed in the inner side-wall portion24and the outer side-wall portion26, it is preferable that the connection marks be formed on the end portions27. Furthermore, since the upper ends of the inner side-wall portion24and the outer side-wall portion26are regions where the deformation amount is large, it is preferable that the connection marks be formed on the upper ends of the left and right portions of the outer side-wall portion26. In the embodiment, the connection mark29is formed on the upper end of the end portion27at the back surface of the left and right portions of the outer side-wall portion26.

Examples

As shown inFIGS.9A to9F, the present inventors prepared six mandibular denture bases10shaped using the method for creating image data according to the embodiment as Examples 1 to 6, respectively. The connection positions of the reinforcing members18of the mandibular denture bases10of Examples 1 to 6 are different from each other. InFIGS.9A to9F, a state of the mandibular denture base10in plan view is illustrated in the upper side, and a state of the mandibular denture base10in side view is illustrated in the lower side when viewed from the back side to the front side along the central axis A.

As shown inFIG.9A, the reinforcing member18of Example 1 is a linear rod-shaped member connected to an upper portion of the end portion on the back side between the left and right portions of the inner side-wall portion of the mandibular denture base10. As shown inFIG.9B, the reinforcing member18of Example 2 is a U-shaped rod-shaped member connected to the upper portion of the end portion on the back side between the left and right portions of the inner side-wall portion of the mandibular denture base10. As shown inFIG.9C, the reinforcing member18of Example 3 is a linear rod-shaped member connected to a lower portion of the end portion on the back side between the left and right portions of the inner side-wall portion of the mandibular denture base10.

As shown inFIG.9D, the reinforcing member18of Example 4 is a linear rod-shaped member connected to an upper portion of a position of the depression10B for a first premolar on the front side between the left and right portions of the inner side-wall portion of the mandibular denture base10. As shown inFIG.9E, the reinforcing member18of Example 5 is a linear rod-shaped member connected to a lower portion of a position of the depression10B for a first premolar on the front side between the left and right portions of the inner side-wall portion of the mandibular denture base10. As shown inFIG.9F, the reinforcing member18of Example 6 is a linear rod-shaped member connected to the lower portion of the position of the depression10B for a first molar on the back side between the left and right portions of the inner side-wall portion of the mandibular denture base10.

In addition, the inventors shaped a mandibular denture base according to Comparative Example 1 including only a main body and having no reinforcing member. A shape of the main body of the mandibular denture base according to Comparative Example 1 is the same as the shape of the main body of the mandibular denture base10of Examples 1 to 6.

In the present example, in order to create the image data100for design of each of Examples 1 to 6 and Comparative Example 1 prior to shaping, “GEOMAGIC DESIGN X” manufactured by 3D Systems was adopted as 3D-CAD of a design image data creation device. Then, the created image data100for design was input to “CARA CAM 2.0” manufactured by Kulzer as CAM of the manufacturing image data creation device, and was arranged at a predetermined angle with respect to the build table region. Then, after the support pin region was vertically extended from the build table region to the arranged image data by CAM to support the image data, image data100A for manufacturing of a plurality of pieces of continuous slice data was created.

Then, the image data100A for manufacturing was transferred to a 3D printer “CARA PRINT 4.0” manufactured by Kulzer as a shaping device, and shaping was performed. As 3D printer ink used for shaping, “DIMA PRINT DENTURE BASE” manufactured by Kulzer was used. Then, the mandibular denture base obtained by shaping was washed, the support pin was removed, and then post-curing was performed. The device used for post-curing was “HILITE POWER 3D” manufactured by Kulzer. Then, 3D image data of each of the front surface on the denture (artificial tooth) side and the back surface on the alveolar ridge (mucosal) side of the post-cured denture base was captured using a 3D scanner “E3” manufactured by 3Shape. Then, the captured 3D image data was input into reverse engineering software “GEOMAGIC DESIGN X” manufactured by 3D Systems and superimposed on the image data100for design, and deviation calculation was performed to calculate a matching score.

The matching score indicates evaluation on displacement between the 3D image data after shaping captured in each of Examples 1 to 6 and Comparative Example 1 and the image data100for design created before shaping. Specifically, displacement (that is, difference) in coordinates of positions of corresponding surfaces between the 3D image data after shaping and the image data100for design before shaping is calculated. Then, a ratio of portions where the calculated displacement is plus (+)/minus (−) 200 μm or less between the two pieces of data is calculated as the matching score. The higher the numerical value of the matching score, the higher the shaping accuracy.

As shown inFIG.10, in the case of Comparative Example 1 having no reinforcing member, the matching score on the front surface side was 70 and the matching score on the back surface side was 80. The matching score of Comparative Example 1 was the lowest on both the front surface side and the back surface side among the compared mandibular denture bases. InFIG.11A, three regions patterned according to the displacement are superimposed on the front surface side of image data100Z for design of Comparative Example 1. In addition, inFIG.11B, three regions patterned according to the displacement are superimposed on the back surface side of the image data100Z for design of Comparative Example 1.

For example, on the front surface side inFIG.11A, displacement of 0.1 μm or more directed upward from the outer side-wall portion16(that is, the upper side in the vertical direction penetrating the paper surface ofFIG.11Avertically) occurs in the region of the left and right portions of the outer side-wall portion16to which the solid oblique line pattern is added. On the back surface side inFIG.11B, displacement of 0.1 μm or more directed downward from the outer side-wall portion16(that is, the lower side in the vertical direction penetrating the paper surface ofFIG.11Bvertically) occurs in the region of the left and right portions of the outer side-wall portion16to which the dotted oblique line pattern is added. In addition, inFIGS.11A and11B, the white region without the solid diagonal line pattern or the dotted diagonal line pattern is a portion where the generated displacement is less than 0.1 μm. FromFIGS.11A and11B, it can be seen that displacement of the inner side-wall portion14and the outer side-wall portion16on the back side including the retromolar pad is particularly large in the case of the mandibular denture base according to Comparative Example 1 having no reinforcing member.

On the other hand, as shown inFIG.10, the matching scores of Examples 1 to 6 were all higher than those of Comparative Example 1, with 72 or more on the front surface side and 81 or more on the back surface side. In particular, the matching score of Example 3 shown inFIG.9Cin which the reinforcing member18that is a linear rod-shaped member was connected to the lower portion of the end portion on the back side between the left and right portions of the inner side-wall portion was 95 on the front surface side and 97 on the back surface side, the highest values among the compared mandibular denture bases.

As shown inFIGS.12A and12B, the inventors prepared two maxillary denture bases20shaped using the method for creating image data according to the embodiment as Examples 7 and 8, respectively. The connection positions of the reinforcing members28of the maxillary denture bases20of Examples 7 and 8 are different from each other.

As shown inFIG.12A, the reinforcing member28of Example 7 is a linear rod-shaped member connected to the upper portion of the end portion27on the back side between the left and right portions of the outer side-wall portion of the maxillary denture base20. As shown inFIG.12B, in Example 8, in addition to the reinforcing member28that is a linear rod-shaped member similar to that of Example 7, a reinforcing member28that is a rod-shaped member connecting the left and right portions of the inner side-wall portion is further provided. The reinforcing member28between the portions of the outer side-wall portion and the reinforcing member28between the portions of the inner side-wall portion in Example 8 have substantially the same diameter, and are arranged at positions substantially overlapping each other in the vertical direction.

In addition, the inventors shaped a maxillary denture base according to Comparative Example 2 having no reinforcing member, as in the case of the mandibular denture base. A shape of the maxillary denture base according to Comparative Example 2 is the same as the shape of the maxillary denture base20of Examples 7 and 8 except that the maxillary denture base has no reinforcing member. Prior to shaping, the image data200for design of each of Examples 7 and 8 and Comparative Example 2 was created under the same conditions as in the case of the mandibular denture base, and the image data200A for manufacturing was created using the created image data200for design. Then, the maxillary denture base was shaped based on the image data200A for manufacturing for each.

As shown inFIG.13, in the case of Comparative Example 2 having no reinforcing member, the matching score on the front surface side was 88 and the matching score on the back surface side was 88. Among the compared maxillary denture bases, the values of the matching scores of Comparative Example 2 were all the lowest.

The matching score of Example 7 and the matching score of Example 8 were both93on the front surface side. On the back surface side, the matching score of Example 7 was 92, while the matching score of Example 8 was 94. The matching score is higher when the reinforcing member28is provided, as in Example 8, both between the left and right portions of the outer side-wall portion and between the left and right portions of the inner side-wall portion of the maxillary denture base20than when the reinforcing member28is provided only between the left and right portions of the outer side-wall portion.

In the method for creating image data of a dental shaped object according to the embodiment, the reinforcing member data118,128, which is the image data of the reinforcing member18,28that reinforces the side-wall portion of the concave portion, is also created in CAD when the image data100,200for design of the denture base is created. Due to this, since the reinforcing member is arranged at a more appropriate position than when the reinforcing member data118,128is created on the CAM side, deformation of the denture base shaped by the 3D printer can be minimized, and the denture base along the image data100,200for design can be shaped. Therefore, the reinforcing member data118,128can be formed with favorable shaping accuracy and excellent stability of shaping accuracy, and in a simple manner.

In the embodiment, since the reinforcing member18,28is one rod-shaped member connecting the left and right portions of the side-wall portion of the concave portion10A,20A, the reinforcing member18,28can have a simple structure.

In the embodiment, the rod-shaped member of the reinforcing member18of the mandibular denture base10connects the end portions17, which are the back side end portions on the front surfaces of the left and right portions of the inner side-wall portion14. In addition, the rod-shaped member of the reinforcing member28of the maxillary denture base20connects the end portions27, which are the back side end portions on the back surfaces of the left and right portions of the outer side-wall portion26. Connecting the end portions17,27, which are the back side end portions of the left and right portions of the side-wall portion that are most easily deformed due to the structural characteristics, with the rod-shaped member can suppress deformation and further enhance the shaping accuracy.

In the embodiment, since the rod-shaped member serving as the reinforcing member18of the mandibular denture base10connects the lower ends, where the deformation amount is particularly large in the left and right portions of the inner side-wall portion14, the shaping accuracy of the mandibular denture base10can be further improved.

In addition, in the embodiment, since the rod-shaped member of the reinforcing member28of the maxillary denture base20connects the upper ends, where the deformation amount is particularly large in the left and right portions of the outer side-wall portion26, the shaping accuracy of the maxillary denture base20can be further improved.

Furthermore, in the embodiment, the reinforcing member28of the maxillary denture base20further has the rod-shaped member that connects the front surfaces of the left and right portions of the inner side-wall portion24of the concave portion20A in the maxillary denture base20. Thus, the shaping accuracy of the maxillary denture base20can be further enhanced.

In the method for manufacturing a dental shaped object according to the embodiment, since the portion that is easily deformed during shaping is reinforced by the reinforcing member18,28in the shaping step, the dental shaped object can be manufactured with favorable and stable shaping accuracy. In particular, in the embodiment, the dental shaped object is the mandibular denture base10and the maxillary denture base20fitted to the alveolar ridge of the patient. When the shaping accuracy of the denture base is enhanced, the fit feeling of the patient wearing the mandibular denture base10and the maxillary denture base20can be enhanced.

In addition, also when the method for creating image data of a dental shaped object according to the embodiment is executed by the computer, the image data of the reinforcing member that reinforces the denture base can be formed with favorable shaping accuracy and excellent stability of shaping accuracy, and in a simple manner.

Other Embodiments

Although the disclosure has been described according to the following disclosed embodiments, it should not be understood that the description and drawings constituting a part of this disclosure limit the disclosure. It should be considered that various alternative embodiments, examples, and operation techniques will become apparent to those skilled in the art from the disclosure. For example, although the design image data creation device40including the CAD function and the manufacturing image data creation device50including the CAM function are exemplified as separate devices in the embodiment, the design image data creation device40and the manufacturing image data creation device50may be integrally configured in the disclosure.

In addition, for example, although a case in which the design image data creation device40has the arithmetic device42and the arithmetic device42executes the method for creating image data has been exemplified in the embodiment, the disclosure is not limited thereto. In the disclosure, a server serving as a computer having an arithmetic device that executes the method for creating image data may be provided separately from the design image data creation device, and the image data creation system of the dental shaped object or the manufacturing system of the dental shaped object may be configured centering on the server. The server can be connected to all of the image data acquisition device, the design image data creation device, the manufacturing image data creation device, and the shaping device, and can control respective operations. By constructing the image data creation system of the dental shaped object or the manufacturing system of the dental shaped object, it is possible to enhance the efficiency of a series of work related to the image data creation of the dental shaped object and the manufacturing of the dental shaped object, and it is possible to efficiently operate respective equipment.

Furthermore, the disclosure may be configured by combining a part of the configurations illustrated inFIGS.1to13. As described above, the disclosure includes various embodiments and the like that are not described above, and the technical scope of the disclosure is defined only by the matters specifying the invention in the claims that are appropriate from the above description.10Mandibular denture base10A Concave portion10B Depression12Top portion14Inner side-wall portion16Outer side-wall portion17End portion18Reinforcing member19Connection mark20Maxillary denture base20A Concave portion20B Depression22Bottom portion24Inner side-wall portion26Outer side-wall portion27End portion28Reinforcing member29Connection mark30Image data acquisition device40Design image data creation device42Arithmetic device42A Image data acquisition unit42B Image data creation unit50Manufacturing image data creation device60Shaping device62Liquid tank63Formation region64Liquid resin66Build table68Suspension member69Light irradiator70Support pin100,100Z Image data for design100A Image data for manufacturing112Top portion region114Inner side-wall portion region116Outer side-wall portion region118Reinforcing member data166Build table region200Image data for design

The disclosure of Japanese Patent Application No. 2020-146114 filed on Aug. 31, 2020 is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each document, patent application, and technical standard were specifically and individually indicated to be incorporated by reference.