prosthetic devices

Abstract

To provide a prosthesis that can suppress deterioration in sense of taste.SOLUTION: A moisture penetrative denture 1 (prosthesis) includes: a low-density structure part 7 having a density structure capable of acquiring moisture penetration; and a high-density structure part 8 having a density structure that is higher than that of the low-density structure part 7.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a prosthetic device that is placed in the oral cavity. [Background technology]

[0002] There are prosthetic devices that are placed in the oral cavity of a subject. Common prosthetic devices placed in the oral cavity include crowns and bridges, removable dentures, and implant dentures. Artificial dental crowns manufactured using additive manufacturing technology also exist. For example, a manufacturing method for manufacturing artificial dental crowns and the like using additive manufacturing technology (e.g., rapid prototyping technology) is known (see, for example, Patent Document 1). In addition, Non-Patent Document 1 is a prior art document related to the present invention. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-157686 [Non-patent literature]

[0004] [Non-Patent Document 1] Hironao Chiba and 5 others, "Fabrication of Release Agent Supply Die with Porous Structure Using Metal-Based Additive Manufacturing", Fig.7~Fig.9, 872 pages, [Online], November 5, 2021, Fuji Technology Publishing Co., Ltd., International Journal of Automation Technology 2021 Vol.15, [Retrieved November 16, 2023], Internet,<URL:https: / / www.fujipress.jp / ijat / au / ijate001500060868 / > Summary of the Invention [Problem to be solved by the invention]

[0005] Figures 8 and 9 of Non-Patent Document 1 show cross-sectional SEM (scanning electron microscope) images of the 3D printer structure when the laser scanning speed and building direction are changed, and the change in pore diameter with laser scanning speed, respectively. The results show that when the laser scanning speed exceeds 1750 mm / s, the pores are continuously interconnected, but the pores are not connected in the horizontal direction except when the laser scanning speed is 2500 mm / s. In this case, the minimum diameter on the surface of the 3D printer structure is 40 μm horizontally and 75 μm vertically. Meanwhile, Figure 7 shows that the continuous pore connection is induced by gaps between linear features. Increasing the laser scanning speed widens the gaps between the linear features, promoting the connection of pores in the horizontal direction. However, increasing the laser scanning speed too much results in the formation of pores, resulting in a decrease in the mechanical properties of the 3D printer structure. The results also suggest the need for a building strategy that considers the balance between mechanical properties and permeability.

[0006] Based on the disclosure in Non-Patent Document 1, it is possible to form a structure with many internal pores (voids), i.e., a porous structure, in both the horizontal and vertical directions after modeling using a 3D printer, and the pores can be formed almost evenly in the modeling direction (layering direction). It is also understood that, while relatively large pores are formed internally as the laser irradiation speed increases, i.e., a porous structure with lower density can be formed, horizontal modeling tends to result in a more even distribution of pores. Thus, Non-Patent Document 1 discloses a technology for actively modeling porous structures, at least in iron materials.

[0007] On the other hand, Patent Document 1 discloses a problem that products manufactured using rapid prototyping technology end up in a porous state, making them unusable for components that require strength. Patent Document 1 also discloses a technique for combining high-performance alloy powders to solve this problem. In other words, it discloses a technique for avoiding a porous structure.

[0008] Generally, when a removable denture is placed to cover the upper or lower jaw, it tends to cause a decrease in taste. This is thought to be because the denture blocks taste components. A decrease in taste can lead to a decrease in the denture wearer's quality of life (QOL). For this reason, there is a demand for dentures that can suppress the decrease in taste. Patent Document 1 avoids a porous structure from the perspective of strength. However, a structure with a density that allows for moisture permeability, such as a porous structure, may be able to suppress the decrease in taste.

[0009] Therefore, an object of the present invention is to provide a prosthetic device that can suppress a decline in taste. [Means for solving the problem]

[0010] The prosthetic device of the present invention is a prosthetic device (1) to be placed in the oral cavity, and is provided with a low-density structural portion (7) having a density structure that provides moisture permeability, and a high-density structural portion (8) having a structure with a higher density than the low-density structural portion.

[0011] The prosthetic device of the present invention is provided with a low-density structural portion having a density structure that provides moisture permeability, and a high-density structural portion having a structure with a density higher than that of the low-density structural portion. Therefore, even when the prosthetic device is attached to the oral cavity, moisture, and ultimately the taste components contained therein, can be delivered to the taste organs located on the opposite side of the prosthetic device through the low-density structural portion. Meanwhile, the high-density structural portion ensures a certain level of strength. Therefore, it is possible to suppress a decrease in taste sensation while maintaining the certain level of strength required for the prosthetic device. In other words, it is possible to realize a prosthetic device that can suppress a decrease in taste sensation.

[0012] Any suitable prosthetic device placed in the oral cavity may be used. For example, a crown, bridge, or implant-supported denture may be used as the prosthetic device. A low-density structural portion may be formed on a suitable portion of such a prosthetic device. For example, one embodiment of the prosthetic device of the present invention may include a major connector (3) to be placed in the maxilla (6) or mandible in the oral cavity, and the low-density structural portion may be provided on at least a portion of the major connector. Prosthetic devices with a major connector often cover a large portion of the palate in the maxilla, which generally tends to cause a decrease in taste sensation. The same is true when placed in the mandible. Therefore, when a low-density structural portion is provided on the major connector, the decrease in taste sensation can be suppressed in prosthetic devices that tend to cause a decrease in taste sensation.

[0013] The low-density structural portion may be formed in an appropriate position, area, size, shape, etc. For example, the low-density structural portion may be circular, rectangular, or polygonal. It may also be formed to an appropriate size depending on the strength required of the prosthetic device (such as the size of the high-density structural portion). The same applies to the position and area. The number of low-density structural portions may be one or more, and may be any appropriate number. For example, in an embodiment in which the low-density structural portion is provided on a large connector, the low-density structural portion may include multiple low-density structural portions each distributed over the large connector. In this case, taste components can be permeated over a wide area, allowing the taste to be experienced in a relatively natural way. On the other hand, by forming multiple low-density structural portions, the overall area of ​​the low-density structural portion can be reduced compared to when a single large low-density structural portion is formed in the same area. This reduces the reduction in strength. As a result, a relatively balanced combination of ensuring strength and reducing the reduction in taste sensation can be achieved.

[0014] The low-density structural portion and the high-density structural portion may be formed of an appropriate material. For example, both the low-density structural portion and the high-density structural portion may be formed of a metal material such as iron or titanium. Alternatively, they may be formed of a non-metal material such as ceramic. The low-density structural portion and the high-density structural portion may also be formed of different materials. Large connectors are generally formed of a material containing cobalt chromium (which may be cobalt chromium alone or may be appropriately mixed with other materials). Therefore, for example, in an embodiment in which the low-density structural portion is formed in the large connector, the large connector may be formed of a material containing cobalt chromium. In this case, the large connector formed of a common material can be provided with the low-density structural portion, and thus with the function of suppressing taste loss.

[0015] The low-density structural portion may be any suitable structure that provides moisture permeability. For example, such low-density structural portions include a porous structure, a grid structure, and a truss structure. Therefore, for example, in one aspect of the prosthetic device of the present invention, the low-density structural portion may be formed of any one of a porous structure, a grid structure, and a truss structure.

[0016] In the above description, reference numerals of the accompanying drawings are given in parentheses to facilitate understanding of the present invention, but this does not mean that the present invention is limited to the illustrated forms. [Effects of the Invention]

[0017] As described above, according to the present invention, it is possible to provide a prosthetic device that can suppress a decline in taste. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a diagram showing a schematic diagram of an example of a moisture-permeable denture placed in the oral cavity. [Figure 2] FIG. 10 is an explanatory diagram illustrating an example of a hollow structure employed in the low-density structural portion. [Figure 3] FIG. 10 is an explanatory diagram illustrating an example of a range in which a low-density structure portion is provided. [Figure 4] FIG. 1 is a diagram schematically illustrating an example of a commonly used denture sample. DETAILED DESCRIPTION OF THE INVENTION

[0019] (Overall composition) The overall structure of a denture according to one embodiment of the present invention will be described below with reference to FIG. 1. Dentures are a type of prosthetic device placed in a person's oral cavity, and a denture according to one embodiment of the present invention is configured as a highly functional denture with a special structure and moisture permeability (hereinafter, it may be referred to as a moisture permeable denture to distinguish it from ordinary dentures). FIG. 1 shows a schematic diagram of an example of a moisture permeable denture placed in the oral cavity. Dentures include types such as bridges, removable dentures, and implant dentures, and moisture permeable dentures can be applied appropriately to these, but the example in FIG. 1 shows the application to a removable denture. Furthermore, removable dentures can be classified into partial dentures and complete dentures, and the example in FIG. 1 shows the application to a partial denture.

[0020] As shown in FIG. 1 , the moisture-permeable denture 1 includes an abutment device 2, a major connector 3, artificial teeth 4, a denture base 5, a minor connector 9, and a proximal plate 10. In the example of FIG. 1 , the abutment device 2, the major connector 3, the minor connector 9, and the proximal plate 10 are shown in dark gray, and the denture base 5 is shown in lighter gray. The abutment device 2 is attached to the abutment teeth (natural teeth used for support) and serves to support and maintain the denture base 5 and the major connector 3 via the abutment teeth. The major connector 3 connects denture bases 5 located apart from each other or connects the denture base 5 to each other and to the abutment device 2, etc. Common major connectors include, for example, palatal bars, palatal straps, and palatal plates for the upper jaw, and lingual bars, lingual plates, and lingual aprons for the lower jaw. Therefore, the major connector 3 may be configured as any of these, but in the example of FIG. 1 , it is configured for the upper jaw and is placed on the palate 6.

[0021] The small connector 9 generally refers to a metal part that connects the abutment device 2 (including various parts such as rests and clasps) to the denture base 5 and the large connector 3. In the example shown in Figure 1, it is configured to connect the abutment device 2 and the large connector 3. The proximal plate 10 is a part that is interposed between the natural teeth and the denture base 5. The abutment device 2, the large connector 3, the small connector 9, and the proximal plate 10 are all made of the same material (typically cobalt chrome or a material containing it, but is not limited to this and may be made of any appropriate material such as titanium). The artificial teeth 4 are artificial teeth made to replace natural teeth. The denture base 5 serves as the base for the artificial teeth 4, supporting the artificial teeth 4 and stabilizing them by adhering to the oral mucosa. Appropriate materials, including common materials, may also be used for the artificial teeth 4 and denture base 5.

[0022] The moisture-permeable denture 1 has a low-density structural portion 7. The low-density structural portion 7 is a portion that has a structure with a lower density (lower mass per unit volume even if made of the same material) compared to other portions. The low-density structural portion 7 is constructed with a density that allows substances that affect taste (taste components) to pass through. This density can be set as appropriate, but as an example, a density that provides moisture permeability is adopted. In other words, the low-density structural portion 7 is constructed to have a structure with a density that provides moisture permeability. The low-density structural portion 7 can be realized with any structure as long as it provides moisture permeability, but as an example, it is realized with a structure (hereinafter sometimes referred to as a hollow structure) that has a cavity within the shaped object that allows moisture to permeate from one side (e.g., the side where food to be chewed is located) to the other side (e.g., the side where taste is sensed, such as the palate 6). Specific examples of hollow structures will be described later.

[0023] The low-density structural portion 7 may be provided in an appropriate portion of the moisture-permeable denture 1, for example, in the denture base 5, but as an example, it is provided in the major connector 3. The low-density structural portion 7 may also be provided appropriately in the major connector 3, for example, the entire major connector 3 may be configured as the low-density structural portion 7 (in which case, other portions, such as the abutment device 2, may function as high-density structural portions that are denser than the low-density structural portion 7), but in the example of Figure 1, it is provided in only a portion near the center. Therefore, the large connector 3 is provided with the low-density structural portion 7 and the high-density structural portion 8, which has a higher density structure. The high-density structural portion 8 may further include multiple structural portions with different densities, but in the example of Figure 1, it is configured as a single structural portion, and all portions of the large connector 3 other than the low-density structural portion 7 (the portion shown in the checkered pattern) are configured as the same high-density structural portion 8.

[0024] (Specific structural example of low-density structure) Next, an example of a specific structure of the low-density structural portion 7 will be described with reference to FIG. 2. FIG. 2 is an explanatory diagram illustrating an example of a hollow structure employed in the low-density structural portion 7. The hollow structure may include any suitable structure, such as a porous structure, a grid structure, and a truss (lattice) structure. FIG. 2(A) schematically illustrates a porous structure, and FIG. 2(B) schematically illustrates a grid structure. Note that the truss structure is not shown, but the truss structure refers to a framework structure made up of multiple triangles, in which triangular voids are formed as cavities. Since voids are formed inside the truss structure, the density is lower than that of the high-density structural portion 8.

[0025] A porous structure is a porous structure with internal voids. On the other hand, a grid structure is a structure with internal cubic lattice-like spaces. Ordinary materials such as metals and plastics have no internal gaps and can be called dense bodies. However, hollow structures such as porous and grid structures differ in that they have many internal voids. This results in a lower density than the high-density structure 8. The internal voids allow moisture to penetrate. For example, as shown in Figure 2(A), in the case of a porous structure, moisture can penetrate in all directions (all directions) through the internal voids. On the other hand, as shown in Figure 2(B), in the case of a grid structure, moisture can penetrate in both the vertical and horizontal directions.

[0026] (Scope of low-density structural parts, etc.) Next, the range in which the low-density structural portion 7 is provided will be described with reference to Fig. 3. Fig. 3 is an explanatory diagram for explaining an example of the range in which the low-density structural portion 7 is provided. In the example of Fig. 3, the large connector 3 in the range in which the low-density structural portion 7 is provided is enlarged and schematically shown. The low-density structural portion 7 can be provided in an appropriate range and position in the large connector 3, but Fig. 3(A) shows an example of a centrally arranged type, and Fig. 3(B) shows an example of a distributed type.

[0027] As shown in FIG. 3A, in the central arrangement type, the low-density structural portion 7 is arranged near the center of the large connector 3. In the example of FIG. 3, the low-density structural portion 7 is formed into a circular shape, but the shape of the low-density structural portion 7 may be any appropriate shape, for example, rectangular or polygonal. Furthermore, the proportion of the low-density structural portion 7 in the large connector 3 (in other words, the area ratio between the low-density structural portion 7 and the high-density structural portion 8) may be set appropriately, for example, depending on the material so as to take into account the reduction in strength (durability) due to the low-density structural portion 7. When setting the proportion, it is more preferable to take into account not only the material but also the intended use, such as the required level of durability.

[0028] As shown in FIG. 3B, in the distributed type, the low-density structural portions 7 are arranged so as to be distributed throughout the large connector 3. In other words, the number of low-density structural portions 7 is not limited to one, and multiple low-density structural portions 7 may be included (multiple low-density structural portions 7 may be provided in the large connector 3). In the example of FIG. 3, low-density structural portions 7 (only one is marked with a symbol) are provided in 12 locations on the large connector 3, but any number of low-density structural portions 7 may be provided in the large connector 3. Also, in the example of FIG. 3, the low-density structural portions 7 are distributed to form rows and columns, but the low-density structural portions 7 may be distributed appropriately, and may be distributed so as to be biased toward a specific portion, such as the right side or the upper side. The number and distribution of the low-density structural portions 7 may be set according to the material or application, for example, as in the example of FIG. 3A.

[0029] (Denture Variations) Next, variations in dentures to which the moisture-permeable denture 1 can be applied will be described with reference to Fig. 4. Fig. 4 is a diagram schematically showing an example of a commonly used denture sample. Fig. 4(A) shows a first sample, and Fig. 4(B) shows a second sample. In the example of Fig. 4, components common to the example of Fig. 1 are assigned the same reference numerals, and descriptions thereof will be omitted.

[0030] As shown in FIG. 4A, the first sample 1A includes a retainer 2, a major connector 3, an artificial tooth 4, and a denture base 5, although the shapes and other features are different. The retainer 2 and the major connector 3 are both made of cobalt chrome, as in the example of FIG. 1 (although the example of FIG. 1 is similar, the retainer 2 and the major connector 3 may be made of different materials. In the example of FIG. 1, the material of the small connector 9 may also be different). In the first sample 1A, the low-density structural portion 7 may be provided in an appropriate portion, for example, in the large connector 3, as in the example of FIG. 1. In this case, the entire large connector 3 may be configured as the low-density structural portion 7 and the retainer 2 may be configured as the high-density structural portion 8, or an appropriate portion of the large connector 3 may be configured as the low-density structural portion 7 and the other portion as the high-density structural portion 8.

[0031] 4(B), second sample 1B includes an abutment device 2, a major connector 3, an artificial tooth 4, and a denture base 5, similar to the example in FIG. 1, although the shape and other features are different. Furthermore, the abutment device 2 is directly connected to the major connector 3, and the small connector 9 is omitted. Second sample 1B may also be provided with a low-density structural portion 7 and a high-density structural portion 8 in appropriate portions. In other words, the low-density structural portion 7 and the high-density structural portion 8 may be provided in appropriate dentures, including first sample 1A and second sample 1B, and dentures provided with them may function as a moisture-permeable denture 1.

[0032] (Manufacturing large connectors including low-density structural parts) The large connector 3 including the low-density structural portion 7 and the support device 2 are manufactured by additive manufacturing using, for example, a 3D printer. This manufacturing can be achieved using a well-known technique that involves repeatedly laying down a metal material (powder) such as cobalt chromium, forming a layer (a layer with the low-density structural portion 7) by laser irradiation according to model data (data representing the desired shape) for the metal material, laying another metal material on top of that layer, and then irradiating it with laser again. For example, by controlling the laser irradiation energy to form voids without fully melting the powder material, a porous structure can be produced. The void size can be formed randomly, and three-dimensional interconnected holes can also be produced. Furthermore, a grid structure can be produced by scanning the laser in a grid pattern to create voids between the scanning pitches. The void size can be controlled to some extent by the scanning pitch (grid pitch). As mentioned above, the interconnected holes tend to be oriented in only one direction (the stacking direction). Similarly, a truss (lattice) structure can be produced by forming a model shape with three-dimensional voids. The void size and communication direction depend on the model shape and molding conditions. Specifically, the technique of Non-Patent Document 1 may be applied, for example, to the manufacture of the large connector 3 including the low-density structural portion 7 as a porous structure.

[0033] As explained above, this embodiment provides a low-density structural portion 7 having a density structure that provides moisture permeability, and a high-density structural portion 8 having an even higher density structure. Therefore, even when the moisture-permeable denture 1 is worn in the oral cavity, moisture, and ultimately the taste components contained therein, can be delivered through the low-density structural portion 7 to the taste organs on the palate located on the opposite side of the moisture-permeable denture 1. Meanwhile, a certain level of strength is ensured by the high-density structural portion 8. This makes it possible to suppress a decrease in taste sensation while maintaining the certain level of strength required for dentures. In other words, it is possible to realize a denture (prosthetic device) that can suppress a decrease in taste sensation.

[0034] Furthermore, as shown in the example of Figure 1, dentures with large connectors 3 often cover a large area of ​​the palate (upper jaw), which generally leads to a loss of taste sensation. The moisture-permeable denture 1 can suppress this loss of taste sensation in dentures prone to this loss of taste sensation. When the low-density structural portion 7 is provided over a wide area in the large connector 3, taste components can penetrate a wide area, allowing for a taste sensation that is relatively close to natural. Furthermore, as shown in the example of Figure 3 (2), when a wide area is formed by distributing multiple low-density structural portions 7, the overall area of ​​the low-density structural portion 7 can be reduced compared to when a single large low-density structural portion 7 is formed over the same area. This suppresses a decrease in strength. As a result, a relatively balanced combination of ensuring strength and suppressing a loss of taste sensation can be achieved. Furthermore, when the large connector 3 is formed from a material containing cobalt chromium, the low-density structural portion 7, and thus the function of suppressing a loss of taste sensation, can be provided to a large connector 3 formed from a general material.

[0035] The present invention is not limited to the above-described embodiments and may be embodied in various modified or altered forms. Furthermore, the present invention may be embodied in various forms obtained by appropriately combining various technical means included in the above-described embodiments and the following modified embodiments. For example, in the above-described embodiment, the moisture-permeable denture 1 is configured as a plate denture. However, the present invention is not limited to such embodiments. For example, the low-density structural portion 7 may be applied to various prosthetic devices such as dental crowns, denture bases, bridges, or implant dentures, as long as a predetermined strength is ensured to ensure functionality. This is because these prosthetic devices are also expected to suppress taste loss. Furthermore, prosthetic devices may include various artificial objects that compensate for missing parts of the human body in addition to those placed in the oral cavity. For example, prosthetic devices may include artificial bones, artificial organs, or artificial eyes. While these may not be expected to reduce taste loss, moisture permeability may be required for various purposes. Therefore, the application of the present invention to these prosthetic devices is not excluded. [Explanation of symbols]

[0036] 1. Moisture-permeable dentures (prosthetic devices) 3 large connectors 6 Palate 7 Low density structure 8 High-density structure

Claims

1. A denture placed in the oral cavity, a low-density structural portion having a structure with a density that allows moisture permeability to be obtained, and a high-density structural portion having a structure with a higher density than the low-density structural portion; a wall portion to be arranged so as to separate the mucous membrane in the oral cavity from a space formed in the oral cavity; The low-density structural portion is provided on the wall portion so as to guide moisture in the space within the oral cavity from the side of the space within the oral cavity to the side of the mucous membrane.

2. a major connector to be placed in the oral cavity on the upper or lower jaw; the low-density structural portion is provided on at least a part of the large connector, The denture of claim 1 , wherein the major connector functions as the wall portion.

3. The denture according to claim 2 , wherein the low-density structural portion includes a plurality of low-density structural portions respectively provided so as to be distributed over the major connector.

4. 4. The denture according to claim 2, wherein the major connector is made of a material containing cobalt chromium.

5. The denture according to any one of claims 1 to 3, wherein the low-density structural portion is formed in any one of a porous structure, a grid structure, and a truss structure.

Images