Partial denture

Abstract

To provide a partial denture achieving prevention of discomfort feeling of a gum inside, appropriate load of occlusal force and effective support of an artificial tooth without disposing a part engaged with a gun inside part in a denture base while retaining a configuration of arranging the denture base between an artificial tooth and an alveolar ridge.SOLUTION: A partial denture comprises: an artificial tooth as a substitute for a missing tooth; a metallic inside wall for backing up the artificial tooth from the inside and engaged with an inside face of an abutment tooth; and a resin denture base for supporting the artificial tooth and engaged with an outside part of a gum. The denture base does not give discomfort feeling to a user due to not having a part engaged with the inside part of the gum, and the inside wall appropriately fixes the partial denture itself by using the abutment tooth while securely supporting the artificial tooth by the inside wall and the denture base.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a partial denture that uses abutment teeth (remaining healthy natural teeth) to prosthesis partially missing teeth. [Background technology]

[0002] Conventional partial dentures, for example as shown in Patent Documents 1 and 2 below, have a structure in which artificial teeth replacing missing teeth are supported by a resin base called a denture base, which resembles the gums. The denture base is positioned so as to straddle the alveolar ridge near the missing area and engages with the outer (cheek side) and inner (lingual side) parts of the gums.

[0003] As a result, the denture base bulges out from the outside and inside of the gums more than the gums would normally bulge. In particular, the part of the denture base that engages with the inside of the gums is the part that comes into contact with the tongue and food, so the bulging part creates a strong sense of discomfort, and it is desirable to eliminate this problem.

[0004] On the other hand, the partial denture in Patent Document 3 listed below has a structure that does not have a denture base, and is inserted by clamping the teeth from both the inside and outside between an inner engaging member that engages with the inside of the teeth and an outer engaging member that engages with the outside of the teeth. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 4270576 [Patent Document 2] Patent No. 4270578 [Patent Document 3] Patent No. 6239181 Summary of the Invention [Problem to be solved by the invention]

[0006] In the partial denture described in Patent Document 3 mentioned above, since there is no denture base itself, there is naturally no part that bulges out on the inside (lingual side), and the user does not feel a strong sense of discomfort on the inside of the gums. However, the biting force that would normally be borne by the alveolar ridge via the denture base is now borne by the abutment teeth alone, which may place excessive strain on the abutment teeth.

[0007] On the other hand, in order to reduce the burden on each abutment tooth, it may be necessary to use not only the remaining teeth adjacent to the missing tooth but also those located far away as abutment teeth, or it may be necessary to use a large number of remaining teeth as abutment teeth, which may result in the partial denture structure becoming larger and more complicated. [Means for solving the problem]

[0008] The present invention provides a partial denture that maintains the configuration of placing a denture base between the artificial teeth and the alveolar ridge, but does not have a portion on the denture base that engages with the inner side of the gums, and has a simple structure that prevents discomfort on the inner side of the gums, properly distributes biting force, and effectively supports the artificial teeth.

[0009] In summary, the partial denture of the present invention comprises artificial teeth to replace missing teeth, a metal inner wall that backs up the artificial teeth from the inside and engages with the inner surfaces of the abutment teeth, and a resin denture base that supports the artificial teeth and engages with the outer side of the gums, and as the denture base has no portion that engages with the inner side of the gums, despite its simple structure, it does not give the user an uncomfortable feeling on the inside of the gums, and the inner wall and denture base securely support the artificial teeth, while the inner wall utilizes the abutment teeth to appropriately fix the partial denture itself.

[0010] Preferably, the artificial tooth, the inner wall and the denture base are integrated via a resin for forming the denture base, and these cooperate to effectively prosthodontic the missing part.

[0011] In addition, the inner wall has a bottom wall portion extending directly below the artificial tooth, and a protrusion portion which is embedded in the denture base forming resin is provided on the bottom wall portion, while a vertical hole which receives the protrusion portion is drilled in the artificial tooth, thereby enabling the artificial tooth, the inner wall and the denture base to be firmly and securely integrated.

[0012] Preferably, the protrusion is cylindrical and has a screw thread or a screw groove on its periphery, which allows the denture base resin to be easily entangled with the periphery, so that the protrusion can be properly embedded in the denture base resin without creating unnecessary gaps around the protrusion.

[0013] Furthermore, by using titanium as the metal for forming the inner wall, the device can be made lightweight and sturdy, and does not impair the oral health of the user.

[0014] Furthermore, by using a thermoplastic resin as the resin for forming the denture base, it is possible to form a denture base that is highly durable and less prone to cracking, and it is also possible to reliably integrate the artificial teeth, the inner wall and the denture base. Effect of the Invention

[0015] According to the partial denture of the present invention, while maintaining the configuration in which a denture base is placed between the artificial teeth and the alveolar ridge, the denture base does not have a portion that engages with the inner side of the gums, thereby preventing any discomfort on the inner side of the gums.

[0016] In addition, despite its simple structure, the artificial teeth are reliably supported by the inner wall and the denture base, and the partial denture itself can be reliably fixed by utilizing the abutment teeth. [Brief description of the drawings]

[0017] [Figure 1] FIG. 2 is an explanatory diagram illustrating a state in which a partial denture according to the present invention is fixed to a missing portion of the mandible, and is a perspective view viewed from the right cheek side. [Diagram 2]FIG. 2 is an explanatory diagram illustrating a state in which a partial denture according to the present invention is fixed to a missing portion of the mandible, and is a perspective view viewed from the left cheek side. [Diagram 3] 2 is a cross-sectional view taken along line AA in FIG. 1. [Figure 4] FIG. 2 is a cross-sectional view taken along line BB in FIG. [Diagram 5] FIG. 2 is a perspective view illustrating the structure of an artificial tooth. [Figure 6] 2 is a cross-sectional view taken along line CC in FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The best mode of the partial denture according to the present invention will be described below with reference to Figures 1 to 6. Figures 1 and 2 are perspective views for explaining the state in which two types of partial dentures 1 according to the present invention are fixed to two missing parts of the lower jaw.

[0019] <Basic configuration of the partial denture according to the present invention> As shown in Figures 1 to 4 and 6, a partial denture 1 according to the present invention has a basic configuration including an artificial tooth 2 replacing a missing tooth, a metal inner wall 3 that backs up the artificial tooth 2 from the inside (lingual side) and engages with the inner surface Tb of the abutment tooth T, and a resin denture base 4 that supports the artificial tooth 2 and engages with the outer (buccal side) portion Ga of the gums G.

[0020] In the partial denture 1 according to the present invention, the shapes of the artificial teeth 2, inner wall 3 and denture base 4 can, of course, be arbitrarily changed or adjusted according to the relationship with the missing teeth or missing parts, and the abutment teeth T used for fixation.

[0021] In the partial denture 1 of the present invention, the artificial teeth 2, inner wall 3 and denture base 4 described above are preferably configured to be integrated via resin 4' used to form the denture base 4, so that they work together to prosthetically replace the missing part.

[0022] <Specific configuration of artificial tooth 2> The artificial tooth 2 is formed to resemble a missing tooth, and is molded from a resin such as a hard resin that has been conventionally used as a material for artificial teeth.

[0023] 5 and 6, the artificial tooth 2 in the present invention is preferably configured to have a vertical hole 2c that opens on the tooth root side of the artificial tooth 2, and a horizontal hole 2d that communicates with the vertical hole 2c and extends in a direction perpendicular to the vertical hole 2c. By inserting a protrusion 3c provided on a bottom wall portion 3b of the inner wall 3, which will be described later, into the vertical hole 2c, and filling the vertical hole 2c and horizontal hole 2d with a denture base forming resin 4' and allowing it to harden, the artificial tooth 2, inner wall 3 and denture base 4 can be firmly integrated.

[0024] As shown in Fig. 5, the horizontal hole 2d can be a through hole to ensure integration with the denture base 4. By forming it as a through hole in this way, the filling operation of the denture base forming resin 4' can be facilitated. As described above, the direction in which the horizontal hole 2d extends may be in the dentition direction, in a direction perpendicular to the dentition direction (inward and outward directions of the teeth), or in other directions, so long as it is perpendicular to the vertical hole 2c, but when it is a through hole, it is preferable that it extends in the dentition direction. This is because the opening of the horizontal hole 2d can be hidden by the adjacent teeth (artificial teeth or abutment teeth), resulting in a partial denture with excellent aesthetics.

[0025] <Specific configuration of the inner wall 3> In the present invention, the inner wall 3 is formed from a metal that is safe to place in the oral cavity, such as a cobalt-chromium alloy or titanium. Preferably, titanium, particularly a 64 titanium alloy, is used to construct a lightweight and sturdy inner wall 3 that is easy to mold. In addition, it is preferable to mold the inner wall 3 with a metal 3D printer, that is, by laminating metal layers. This is because, as will be described later, it is possible to mold the inner wall 3 into a shape that closely follows the shape of the inner surface of the artificial tooth 2 or the abutment tooth T.

[0026] 1 to 4 and 6, the inner wall 3 is provided continuously along the inner surface 2b of the artificial tooth 2 and also along the inner surface Tb of the abutment tooth T adjacent to the artificial tooth 2. In other words, the inner wall 3 is a single wall formed following the surface shape of the inner surface 2b of the artificial tooth 2 and the surface shape of the inner surface Tb of the abutment tooth T, and supports the artificial tooth 2 together with the denture base 4 described later, and fixes the partial denture 1 itself using the abutment tooth T.

[0027] Furthermore, as shown in Figure 3, the inner wall 3 directly engages with the inner surface Tb of the abutment tooth T, contributing to the fixation of the partial denture 1 and also directly backing up the inner surface 2b of the artificial tooth 2. As shown in Figure 4, the inner wall 3 also backs up the artificial tooth 2 along the inner surface 2b via the denture base 4 (denture base molding resin 4').

[0028] 1 to 3 and 6 denotes a rest portion formed integrally with the inner wall 3. The rest portion 3a engages with the occlusal surface of the abutment tooth T used to fix the partial denture 1, preventing the partial denture 1 from sinking and appropriately dispersing the occlusal force applied to the partial denture 1.

[0029] Preferably, as shown in Figures 4 and 6, the inner wall 3 has an integral bottom wall 3b extending directly below the artificial tooth 2, and a protrusion 3c is provided on the bottom wall 3b. The protrusion 3c is inserted into the vertical hole 2c of the artificial tooth 2 and embedded in the denture base forming resin 4', thereby effectively integrating the artificial tooth 2, the inner wall 3, and the denture base 4 while maintaining a simple structure. Thus, the inner wall 3 and the denture base 4 can firmly and reliably support the artificial tooth 2 and can fix the partial denture 1 itself, and can therefore appropriately bear the occlusal force applied to the partial denture 1.

[0030] Preferably, the protrusion 3c on the bottom wall 3b is cylindrical and has a screw thread or a screw groove on its periphery, which makes it easier for the denture base resin 4' to become entangled with the periphery. Therefore, no unnecessary gaps are generated around the protrusion 3c, and the protrusion 3c can be appropriately embedded in the denture base resin 4'.

[0031] <Specific configuration of denture base 4> As described above, in the partial denture 1 according to the present invention, the resin denture base 4 cooperates with the inner wall 3 to support the artificial teeth 2 and to fix the partial denture 1 itself, and has an outer engagement portion 4a that engages with the outer part Ga of the gums G. As shown in Fig. 4, the outer engagement portion 4a engages with the outer surface 2a of the artificial teeth 2 and can be configured to engage with the outer surface Ta of the abutment tooth T, if necessary.

[0032] On the other hand, in the partial denture 1 of the present invention, the denture base 4 does not have a portion that engages with the inner portion Gb of the gums G. Therefore, the inner portion Gb of the user's own gums G is exposed, and the user does not feel uncomfortable in that portion.

[0033] Furthermore, by using a thermoplastic resin such as polyamide or polypropylene as the denture base forming resin 4', it is possible to easily mold the denture base 4 and reduce its weight. Preferably, the denture base 4 is colored in a color close to that of the gums G.

[0034] With the protrusion 3c erected on the bottom wall portion 3b of the inner wall 3 inserted into the vertical hole 2c of the artificial tooth 2 described above, a resin filling space is defined by a formwork, and denture base forming resin 4' is filled into this space, the gap between the artificial tooth 2 and the inner wall 3, and the vertical hole 2c and horizontal hole 2d of the artificial tooth 2 and allowed to harden.At the same time, the denture base 4, the inner wall 3 and the artificial tooth 2 are integrated as shown in Figures 4 and 6 to form the partial denture 1 of the present invention.

[0035] Therefore, the partial denture 1 according to the present invention maintains the configuration of disposing the denture base 4 between the artificial teeth 2 and the alveolar ridge A as in conventional partial dentures, but does not give the user a sense of discomfort at the inner gingival part Gb. More specifically, in the partial denture 1 according to the present invention, the integrated inner side wall 3 and denture base 4 are disposed on the alveolar ridge A while firmly supporting the artificial teeth 2 at the missing part, and the denture base 4 engages with the outer gingival part Ga, while the inner side wall 3 engages with the inner surface Tb of the abutment tooth T.

[0036] As described above, in the partial denture 1 according to the present invention, the denture base 4 does not have a portion that engages with the inner portion Gb of the gums G, so the user does not feel any discomfort. Furthermore, like a conventional partial denture with a denture base, the artificial teeth 2 are placed in the missing parts and can be easily attached by simply pushing them into the root side of the abutment teeth T.

[0037] Furthermore, although the structure is simple, the artificial tooth 2, inner wall 3 and denture base 4 are firmly integrated via the denture base forming resin 4', so even if the denture base 4 does not have a portion that engages with the inner part Gb of the gums G, the denture base 4 and the inner wall 3 can firmly support the artificial tooth 2 while appropriately bearing the occlusal force.

[0038] In particular, the configuration of the vertical hole 2c and horizontal hole 2d of the artificial tooth 2 and the configuration of the bottom wall portion 3b and protrusion portion 3c of the inner wall 3 enable the artificial tooth 2, the inner wall 3 and the denture base 4 to be more firmly integrated. [Explanation of symbols]

[0039] 1...Partial dentures, 2...artificial tooth, 2a...outer surface of artificial tooth, 2b...inner surface of artificial tooth, 2c...vertical hole, 2d...horizontal hole, 3...Inner wall, 3a...Rest part, 3b...Bottom wall part, 3c...Protrusion part, 4: denture base, 4a: outer engagement portion, 4': denture base forming resin, T... abutment tooth, Ta... outer surface of abutment tooth, Tb... inner surface of abutment tooth, G...gingiva, Ga...outer gingiva, Gb...inner gingiva, A...alveolar ridge.

Claims

1. A partial denture comprising an artificial tooth to replace a missing tooth, a metal inner wall that backs up the artificial tooth from the inside and engages with the inner surface of the abutment tooth, and a resin denture base that supports the artificial tooth and engages with the outer side of the gums, the denture base having no portion that engages with the inner side of the gums.

2. 2. The partial denture according to claim 1, wherein said artificial teeth, said inner wall and said denture base are integrated together via a resin for forming said denture base.

3. A partial denture as described in claim 2, characterized in that the inner wall has a bottom wall portion extending directly below the artificial tooth, and a protrusion portion to be embedded in the denture base forming resin is provided on the bottom wall portion, while a vertical hole to receive the protrusion portion is drilled in the artificial tooth.

4. 4. The partial denture according to claim 3, wherein the protrusion is cylindrical and has a screw thread or a screw groove on its lateral periphery.

5. 2. The partial denture according to claim 1, wherein the metal forming said inner wall is titanium.

6. 3. The partial denture according to claim 2, wherein the resin forming the denture base is a thermoplastic resin.

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