Prosthesis

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 installed in the oral cavity.

Background Art

[0002] There are prosthetic devices installed in the oral cavity of a subject. Prosthetic devices installed in the oral cavity are generally things such as crown bridges, complete dentures, and implant dentures. There are also artificial dental crowns manufactured by additive manufacturing technology. For example, a manufacturing method for manufacturing artificial dental crowns and the like by additive manufacturing technology (for example, rapid prototyping technology) is known (see, for example, Patent Document 1). In addition, Non-Patent Document 1 exists as a prior art document related to the present invention.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Non-Patent Documents

[0004]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In Figs. 8 and 9 of Non-Patent Document 1, cross-sectional SEM (scanning electron microscope) images of the formed structure and changes in pore diameter according to the laser scan speed are shown when the laser scan speed and the forming direction in a 3D printer are changed. And it is shown that when the laser scan speed exceeds 1750 mm / s, the pores are continuously connected, while in the horizontal direction, except when the laser scan speed is 2500 mm / s, the pores were not connected. Note that the minimum pore diameter on the surface of the formed body in this case is 40 μm in the horizontal direction and 75 μm in the vertical direction. On the other hand, in Fig. 7, the continuous connection of the pores is induced by the gaps between the linear formations. When the laser scan speed is increased, the gaps between the linear formations widen, promoting the connection of the pores in the horizontal direction. However, when the laser scan speed is increased too much, pores are formed, and the mechanical properties of the formed body are shown to deteriorate. And findings regarding the necessity of a forming strategy considering the balance between mechanical properties and water permeability are shown.

[0006] Based on the disclosure of Non-Patent Document 1, it can be found that in a 3D printer, a structure with many pores (spaces) inside, that is, a porous structure, can be formed in both the horizontal and vertical directions after forming, and the pores can be formed almost evenly in the forming direction (lamination direction). Also, it can be understood that relatively large pores are formed inside as the laser irradiation speed increases, that is, a porous structure with a lower density can be formed, while forming in the horizontal direction is relatively less biased and the pores tend to be widely distributed. Thus, Non-Patent Document 1 discloses a technique for actively forming a porous structure at least in iron materials.

[0007] On the other hand, Patent Document 1 discloses a problem that a product formed by rapid prototyping technology is in a porous state and cannot be used as a member that requires strength. And as a technique for solving this problem, a combination technique of high-performance alloy powders is disclosed. In other words, a technique for avoiding a porous structure is disclosed.

[0008] Generally, when a denture with a base is placed to cover the upper jaw or the lower jaw, it tends to cause a decrease in taste. This is presumably because the denture inhibits the taste components. The decrease in taste may lead to a decline in the QOL (Quality of Life) of the denture wearer. For this reason, there is a demand for a denture that can suppress the decrease in taste. In Patent Document 1, a porous structure is avoided from the viewpoint of strength. However, for example, a structure with a density that provides water 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 capable of suppressing a decrease in taste.

Means for Solving the Problems

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

[0011] According to the prosthetic device of the present invention, a low-density structure portion having a structure with a density that provides water permeability and a high-density structure portion having a structure with a higher density than the low-density structure portion are provided. For this reason, even when the prosthetic device is worn in the oral cavity, moisture, and thus the taste components contained therein, can reach the taste organs located on the opposite side of the prosthetic device through the low-density structure portion. On the other hand, a certain strength is ensured by the high-density structure portion. Therefore, it is possible to suppress a decrease in taste while maintaining a certain strength required for the prosthetic device. That is, it is possible to realize a prosthetic device capable of suppressing a decrease in taste.

[0012] As a prosthetic device, an appropriate object installed in the oral cavity may be adopted. For example, a crown bridge or an implant denture may be adopted as the prosthetic device. And a low-density structure part may be formed in an appropriate part of those prosthetic devices. For example, in one form of the prosthetic device of the present invention, it has a major connector (3) to be arranged in the upper jaw (6) or the lower jaw in the oral cavity, and the low-density structure part may be provided in at least a part of the major connector. Prosthetic devices with major connectors often cover a large part of the palate in the upper jaw and generally tend to cause a decrease in taste easily. The same is true when arranged in the lower jaw. Therefore, when a low-density structure part is provided in the major connector, the decrease can be suppressed in a prosthetic device that easily causes a decrease in taste.

[0013] The low-density structure part may be formed at an appropriate position, range, size, shape, etc. For example, the low-density structure part may be circular, rectangular, or polygonal. Also, it may be formed in an appropriate size according to the strength required for the prosthetic device (such as the size of the high-density structure part). The same is true for the position and range. The number of low-density structure parts may be one or a plurality, and may be an appropriate number. For example, in the aspect where the low-density structure part is provided in the major connector, the low-density structure part may include a plurality of low-density structure parts provided so as to be distributed in the major connector. In this case, since the taste components can penetrate in a wide range, the taste can be felt in a relatively natural feeling. On the other hand, by forming a plurality of low-density structure parts, the overall area of the low-density structure part can be made smaller compared to the case where a large single low-density structure part is formed in the same range. Thereby, the decrease in strength can be suppressed. As a result, it is possible to relatively well balance ensuring strength and suppressing a decrease in taste.

[0014] The low-density structure part and the high-density structure part may be formed of an appropriate material. For example, both the low-density structure part and the high-density structure part 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. Also, the low-density structure part and the high-density structure part may be formed of different materials. The large connector is generally often formed of a material containing cobalt chromium (it may be only cobalt chromium or other materials may be appropriately mixed). Therefore, for example, in the aspect where the low-density structure part is formed in the large connector, the large connector may be formed of a material containing cobalt chromium. In this case, a low-density structure part can be provided in a large connector formed of a general material, and thus a function of suppressing taste reduction can be provided.

[0015] The low-density structure part may have an appropriate structure that provides water permeability. For example, such low-density structure parts 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 structure part may be formed in any one of the porous structure, the grid structure, and the truss structure.

[0016] In the above description, for the sake of easy understanding of the present invention, the reference numerals of the accompanying drawings are appended in parentheses, but the present invention is not limited to the illustrated forms thereby.

Effects of the Invention

[0017] As described above, according to the present invention, a prosthetic device capable of suppressing a decrease in taste can be provided.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0019] (Overall Configuration) First, with reference to FIG. 1, the overall configuration of a denture according to one embodiment of the present invention will be described below. A denture is a type of prosthetic device installed in a person's oral cavity. However, the denture according to one embodiment of the present invention has a special structure and is configured as a high-functional denture with water permeability (hereinafter, may be referred to as a water-permeable denture to distinguish it from a general denture). FIG. 1 schematically shows an example of a water-permeable denture installed in the oral cavity. Dentures include types such as fixed partial dentures (so-called bridges), complete dentures, and implant dentures, etc. The water-permeable denture can be appropriately applied to them. In the example of FIG. 1, the case of application to a complete denture is shown. Also, complete dentures can be classified into partial dentures and complete dentures. In the example of FIG. 1, the case of application to a partial denture is shown.

[0020] As shown in FIG. 1, the water-permeable denture 1 includes a retainer 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 retainer 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 a lighter gray than them. The retainer device 2 is a part installed on the abutment teeth (the teeth used for support among natural teeth), and plays a role of supporting and maintaining the denture base 5 and the major connector 3 via the abutment teeth. The major connector 3 is a part that connects the denture bases 5 at distant positions, or each part such as the denture base 5 and the retainer device 2. General major connectors include, for example, the palatal bar, palatal strap, and palatal plate for the upper jaw, and the lingual bar, lingual plate, and lingual apron for the lower jaw, etc. Therefore, the major connector 3 may be configured as any of these. In the example of FIG. 1, it is configured for the upper jaw and is arranged on the palate 6.

[0021] The small connector 9 generally refers to the metal part that connects the abutment device 2 (including various parts such as rests and clasps) to the denture base 5 or the major connector 3. In the example of FIG. 1, it is configured to connect the abutment device 2 and the major connector 3. The adjacent panel 10 is the part interposed between the natural tooth and the denture base 5. The abutment device 2, the major connector 3, the small connector 9, and the adjacent panel 10 are all formed of the same material (generally, cobalt-chromium or a material containing it is often used, but it is not limited thereto, and for example, an appropriate material such as titanium may be used). The artificial tooth 4 is a tooth artificially made in place of the natural tooth. The denture base 5 is the part that serves as the base for the artificial tooth 4, supports the artificial tooth 4, and plays a role in stabilizing the artificial tooth 4 by closely adhering to the oral mucosa. Appropriate materials including common materials may also be used for the artificial tooth 4 and the denture base 5.

[0022] The water-permeable denture 1 is provided with a low-density structure part 7. The low-density structure part 7 is a part having a low-density structure (even if it is the same material, the mass per unit volume is low) compared to other parts. The low-density structure part 7 is configured with a density that allows a substance (flavor component) that affects taste to permeate. This density can be set as appropriate, but as an example, a density that provides water permeability is adopted. That is, the low-density structure part 7 is configured to have a structure with a density that provides water permeability. The low-density structure part 7 can be realized with an appropriate structure as long as water permeability is obtained. As an example, it is realized with a structure having cavities (hereinafter sometimes referred to as a hollow structure) in which water can permeate from one side (for example, the side where the food to be chewed is located) to the opposite side (for example, the side of the part where taste is felt such as the palate 6) in the molded object. Specific examples of the hollow structure will be described later.

[0023] The low-density structure portion 7 may be provided at an appropriate portion of the water-permeable denture 1. For example, it may be provided on the denture base 5, but as an example, it is provided on the major connector 3. Further, the low-density structure portion 7 may be appropriately provided on the major connector 3. For example, the entire major connector 3 may be configured as the low-density structure portion 7 (in this case, for example, other portions such as the abutment device 2 may function as a high-density structure portion having a higher density than the low-density structure portion 7), but in the example of FIG. 1, it is provided only on a part near the center. Therefore, the major connector 3 is provided with the low-density structure portion 7 and the high-density structure portion 8 having a structure with a higher density than that. The high-density structure portion 8 may further have a plurality of structure portions with different densities, but in the example of FIG. 1, it is configured as one structure portion, and all portions of the major connector 3 other than the low-density structure portion 7 (the portion shown in a grid pattern) are configured as the same high-density structure portion 8.

[0024] (Specific structural example of the low-density structure portion) Next, with reference to FIG. 2, an example of the specific structure of the low-density structure portion 7 will be described. FIG. 2 is an explanatory diagram for explaining an example of the hollow structure adopted for the low-density structure portion 7. The hollow structure may include an appropriate structure, for example, a porous structure, a grid structure, or a truss (lattice) structure. (A) of FIG. 2 schematically shows a porous structure, and (B) shows a grid structure. Although the illustration of the truss structure is omitted, the truss structure means a framework structure formed by a plurality of triangles, and is a structure in which triangular voids are formed as cavities. Since voids are also formed inside the truss structure, its density is lower than that of the high-density structure portion 8.

[0025] The porous structure is a porous structure with pores inside. On the other hand, the grid structure is a structure with a three-dimensional lattice-like space inside. Materials such as ordinary metals and plastics can be called dense bodies without gaps inside, but hollow structures such as the porous structure and the grid structure are different from them and have many pores and the like inside. For this reason, the density is lower than that of the high-density structure portion 8. And the internal pores and the like realize the penetration of moisture. For example, as shown in (A) of FIG. 2, in the case of the porous structure, moisture can penetrate in all directions (all directions) through the internal pores. On the other hand, as shown in (B) of FIG. 2, in the case of the grid structure, moisture can penetrate in the vertical direction.

[0026] (Range of the low-density structure portion, etc.) Next, with reference to FIG. 3, the range where the low-density structure portion 7 is provided and the like will be described. FIG. 3 is an explanatory diagram for explaining an example of the range where the low-density structure portion 7 is provided. In the example of FIG. 3, the large connector 3 in the range where the low-density structure portion 7 is provided is enlarged and schematically shown. The low-density structure portion 7 can be provided in an appropriate range and at an appropriate position in the large connector 3. In (A) of FIG. 3, an example of the central arrangement type is shown, and in (B), an example of the distributed type is shown.

[0027] As shown in (A) of FIG. 3, in the central arrangement type, the low-density structure portion 7 is arranged near the center of the large connector 3. In the example of FIG. 3, the shape of the low-density structure portion 7 is formed in a circular shape, but the shape of the low-density structure portion 7 can be appropriate, for example, rectangular or polygonal. Also, the ratio of the low-density structure portion 7 to the large connector 3 (in other words, the area ratio between the low-density structure portion 7 and the high-density structure portion 8) can be set appropriately. For example, it can be set according to the material so that the decrease in strength (durability) due to the low-density structure portion 7 is considered. When setting the ratio, in addition to the material, it is more preferable to consider applications such as how much durability is required.

[0028] As shown in (B) of FIG. 3, in the distributed type, the low-density structure portions 7 are arranged so as to be distributed over the entire large connector 3. That is, the low-density structure portions 7 are not limited to one, and there may be a case where a plurality of low-density structure portions 7 are included (a plurality of low-density structure portions 7 are provided in the large connector 3). In the example of FIG. 3, low-density structure portions 7 (only one reference numeral is attached) are provided at 12 locations of the large connector 3, but an appropriate number of low-density structure portions 7 may be provided in the large connector 3. Further, in the example of FIG. 3, each low-density structure portion 7 is distributed so as to form rows and columns, but each low-density structure portion 7 may be distributed as appropriate, and may be distributed so as to be biased to a specific portion such as the right side or the upper side, for example. The number and distribution of the low-density structure portions 7 may be set according to the material or application, for example, in the same manner as the example of (A) of FIG. 3.

[0029] (Variations of dentures) Next, with reference to FIG. 4, variations of dentures to which the water-permeable denture 1 can be applied will be described. FIG. 4 is a diagram schematically showing an example of a sample of a generally used denture. In (A) of FIG. 4, a first sample is shown, and in (B), a second sample is shown. In the example of FIG. 4, the same reference numerals are given to the configurations common to the example of FIG. 1, and the description thereof is omitted.

[0030] As shown in (A) of FIG. 4, the first sample 1A includes an abutment device 2, a large connector 3, artificial teeth 4, and a denture base 5, although the shapes and the like are different. Both the abutment device 2 and the large connector 3 are made of cobalt-chromium in the same manner as in the example of FIG. 1 (although the same is true for the example of FIG. 1, the materials of the abutment device 2 and the large connector 3 may be different. In the example of FIG. 1, the material of the small connector 9 may also be different from them.). In the first sample 1A, the low-density structure portions 7 may be provided at appropriate portions, and may be provided in the large connector 3, for example, in the same manner as in the example of FIG. 1. In this case, the entire large connector 3 may be configured as the low-density structure portion 7, and the abutment device 2 may be configured as the high-density structure portion 8, or an appropriate part of the large connector 3 may be configured as the low-density structure portion 7 and the other part may be configured as the high-density structure portion 8, respectively.

[0031] Also, as shown in (B) of FIG. 4, the second sample 1B includes the abutment device 2, the major connector 3, the artificial tooth 4, and the denture base 5, although the shape and the like are different from those in the example of FIG. 1. Also, the abutment device 2 is directly connected to the major connector 3, and the minor connector 9 is omitted. In the second sample 1B as well, the low-density structure portion 7 and the high-density structure portion 8 may be provided at appropriate portions. That is, the low-density structure portion 7 and the high-density structure portion 8 may be provided in an appropriate denture including the first sample 1A and the second sample 1B, and the denture provided with them may function as the water-permeable denture 1.

[0032] (Manufacture of Major Connector Including Low-Density Structure Portion) The major connector 3 and the abutment device 2 including the above-described low-density structure portion 7 are manufactured by additive manufacturing using a 3D printer as an example. This shaping can be realized by a well-known technique that repeats procedures such as laying a metal material (powder) such as cobalt-chromium, forming a layer (a layer having the low-density structure portion 7) by laser irradiation according to model data (data indicating a desired shape) for the metal material, laying the metal material again on the layer, and performing laser irradiation again. For example, by shaping in a state where the powder material is not sufficiently melted by controlling the irradiation energy of the laser, voids can be formed and a porous structure can be manufactured. The void sizes are formed randomly, and three-dimensional through-holes can also be shaped. Also, by making voids between the scanning pitches by scanning the laser in a grid pattern, a grid structure can be manufactured. The void size can be controlled to some extent by the scanning pitch (the pitch of the grid). The direction of the through-holes tends to be only in one direction (the lamination direction) as described above. Similarly, a truss (lattice) structure can be manufactured by shaping according to a model shape having voids three-dimensionally. The void size and the communication direction depend on the model shape and the shaping conditions. Specifically, for manufacturing the major connector 3 including the low-density structure portion 7 as a porous structure, the technique of Non-Patent Document 1 may be applied as an example.

[0033] As described above, according to this embodiment, a low-density structure portion 7 having a structure with a density that provides water permeability and a high-density structure portion 8 having a higher-density structure are provided. Therefore, even when the water-permeable denture 1 is worn in the oral cavity, water, and thus the flavor components contained therein, can reach the taste organs on the palate located on the opposite side of the water-permeable denture 1 through the low-density structure portion 7. On the other hand, a certain strength is ensured by the high-density structure portion 8. For this reason, it is possible to suppress a decrease in taste while maintaining a certain strength required for the denture. That is, it is possible to realize a denture (prosthetic device) that can suppress a decrease in taste.

[0034] Also, as shown in the example of FIG. 1, dentures having a major connector 3 often cover the palate (upper jaw) widely and generally tend to cause a decrease in taste. The water-permeable denture 1 can suppress such a decrease in taste in dentures that are prone to causing such a decrease in taste. When the low-density structure portion 7 is provided in a wide range in the major connector 3, flavor components can penetrate in a wide range, so that the taste can be felt in a relatively natural feeling. Further, for example, as shown in the example of (2) in FIG. 3, when a wide range is formed by the distribution of a plurality of low-density structure portions 7, the total area of the low-density structure portion 7 can be made smaller than when a single large low-density structure portion 7 is formed in the same range. Thereby, a decrease in strength can be suppressed. As a result, it is possible to relatively well balance ensuring strength and suppressing a decrease in taste. And when the major connector 3 is formed of a material containing cobalt-chromium, it is possible to provide the major connector 3 formed of a general material with the low-density structure portion 7 and thus a function of suppressing a decrease in taste.

[0035] The present invention is not limited to the above-described forms and may be implemented in appropriately modified or changed forms. Further, the present invention may be implemented in a form obtained by appropriately combining various technical means included in the above-described forms and forms subjected to the following modifications and the like. For example, in the above-described form, the water-permeable denture 1 is configured as a complete denture. However, the present invention is not limited to such a form. For example, the low-density structure portion 7 may be applied to various prosthetic devices such as a dental crown, a denture base, a bridge, or an implant denture as long as a predetermined strength ensuring the function is secured. This is because suppression of taste reduction is also expected in these prosthetic devices. Further, prosthetic devices may include various artificial articles that supplement defective parts of the human body in addition to those installed in the oral cavity. For example, articles such as artificial bones, artificial organs, or artificial eyes may also be included in prosthetic devices. Although taste reduction may not be expected in these, there is a possibility that water permeability is required for various purposes. Therefore, the application of the present invention to these prosthetic devices is not excluded.

Explanation of Signs

[0036] 1 Water-permeable denture (prosthetic device) 3 Major connector 6 Palate 7 Low-density structure portion 8 High-density structure portion

Claims

Claim 1 A prosthetic device to be installed in the oral cavity, The prosthetic device is provided with a low-density structure portion having a structure with a density that allows water penetration and a high-density structure portion having a structure with a higher density than the low-density structure portion. Claim 2 Having a major connector to be arranged in the upper jaw or the lower jaw in the oral cavity, The prosthetic device according to claim 1, wherein the low-density structure portion is provided on at least a part of the major connector. Claim 3 The prosthetic device according to claim 2, wherein the low-density structure portion includes a plurality of low-density structure portions respectively provided so as to be distributed on the major connector. Claim 4 The prosthetic device according to claim 2 or 3, wherein the major connector is formed of a material containing cobalt chromium. Claim 5 The prosthetic device according to any one of claims 1 to 3, wherein the low-density structure portion is formed in any one of a porous structure, a grid structure, and a truss structure.

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