JPH02944B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention can provide stable and strong support to the alveolar ridge, thereby preventing wobbling, involuntary tenderness, falling off, etc. during mastication. This invention relates to a denture that can be made and a method for manufacturing the same.

Prior Art FIG. 1 shows a typical example of a conventional denture 1, which is composed of an artificial tooth 2 and a denture base 3 to which the artificial tooth 2 is fixed. As shown in FIG. 2, the denture base 3 has an inner surface 4 having a substantially inverted U-shaped cross section, and this surface is in close contact with the alveolar ridge 5 mucous membrane. Generally, the denture 1 is constructed so that it can be easily removed for cleaning, but on the other hand, it often falls off against the user's will, or it may shift during mastication and cause unpleasant tenderness, causing inconvenience to the user. has not been resolved. The structure shown in FIGS. 3A and 3B is a structure that has been proposed in the past to eliminate this inconvenience, and is one in which a groove 6 is formed at the bottom of the U-shaped inner surface 4 (for example, in the Utility Model 58 -51710). With such a structure, when the denture is first used, air escapes from the space formed in the groove 6 as shown in Figure A during mastication to the outside through the contact surface of the denture base 3 and the alveolar ridge 5, and the inside of the space is becomes a negative pressure state, and the denture 1 sticks to the alveolar ridge 5, but as it is repeatedly used, the gums invade into the groove 6 as shown in Figure B, the space disappears, and the suction effect can no longer be obtained. It has the disadvantage of being

Purpose of the Invention The present invention solves the above-mentioned drawbacks, and provides a denture that stabilizes the denture fixation and allows smooth mastication movements while maintaining the advantage of being freely removable, and a method for manufacturing the denture. That purpose.

Structure of the Invention The denture according to the present invention includes: a recess formed on the inner surface of the denture base so as to form a sealed space between the denture base and the alveolar ridge mucosal surface; a small hole communicating from the recess to the outer surface of the denture base; Valve means formed in the small hole to allow air to pass only from the recess to the outer surface of the denture base; gingival invasion prevention means for preventing gingiva from entering the recess; and at least a peripheral portion of the inner surface of the denture base. The gist thereof is to have a rubber-like elastic member.

The method for manufacturing a denture according to the present invention also includes the steps of: forming a jaw model having a shape matching the alveolar ridge shape using a plastic material such as plaster; covering the jaw model with a first spacer having a predetermined thickness; After that, a step of forming a pseudo denture base made of wax on the first spacer and arranging artificial teeth on the pseudo denture base; covering the artificial teeth, the pseudo denture base and the first spacer with a plastic material and heating it; Step of removing the pseudo denture base made of the wax by treatment etc.; Step of filling the wax removal space with a denture base forming material such as a synthetic resin to form a denture base; Removing the first spacer and forming a recess. With the second spacer disposed in the region, a molten rubber-like elastic member is injected into the first spacer space and then hardened to form a rubber-like elastic member having a recess that is adhered to the inner surface of the denture base. The gist thereof includes the following steps: forming a small hole in the denture base that communicates the outer surface of the denture base with the recess, and forming a valve means in the small hole.

Embodiment FIGS. 4 to 6 show embodiments of the present invention,
FIG. 4 shows the back structure of the denture 1 that is fitted into the lower jaw. 2 and 3 are the aforementioned artificial teeth and denture base, respectively; 7 is a rubber-like elastic member (hereinafter simply referred to as an elastic member) made of rubber or synthetic resin formed by covering the inner surface of the denture base 3; It is fixed at 3. Here, both of the above can be fixed using an adhesive that is harmless to the human body, but adhesives generally contain harmful substances such as organic solvents, and therefore the types that can be used are limited. Considering this, it is desirable to bond directly by fusion bonding without using an adhesive. In view of this, the present inventors have determined the solubility parameters (hereinafter referred to as SP) of the three denture base materials.
By setting the SP value of the elastic member 7 and the SP value of the elastic member 7 to be substantially equal, it is possible to easily fuse the two. For example, when polymethyl methacrylate resin is used as the denture base 3 material, its SP value is 9.3. Therefore, in this case, a urethane thermoplastic elastomer having an SP value of 10.0 can be used. Such thermoplastic elastomers have approximately 100
The material is heated to a temperature above .degree. C. and in a softened or melted state is coated and fixed onto a predetermined surface of the denture base 3. Here, the SP value that is substantially equal to the SP value of the denture base 3 refers to one that is within a range of approximately ±15% based on the SP value of the denture base 3, and the SP value of the polymethyl methacrylate resin (SP value In the case of 9.3), the range of SP values that can be used as the elastic member 7 is:
It ranges from about 7.9 to 10.7. Within this range, the elastic member 7 can be fused to the denture base 3. 8 is a recess formed at the bottom of the U-shaped portion of the elastic member 7, and 9, 9, . . . are a number of convex portions formed within this recess 8. The convex portions 9, 9, . . . function as a means for preventing intrusion into the gums. That is, as a result of mastication, the space formed between the recess 8 and the alveolar ridge 5 becomes a negative pressure, and the gums are sucked into this space and protrude slightly. As the chewing action is repeated in this way, the gums deform along the wall surface of the recess 8 and try to fill it, but the recess 8 is formed into a minutely uneven surface by the convex parts 9, 9... Therefore, it is not possible to completely satisfy this requirement. Therefore, despite some deformation of the gingiva, the space within the recess 8 is maintained and the suction effect due to the negative pressure is not impaired. Reference numeral 10 denotes a small air vent hole formed in the denture base 3 and the elastic member 7 to communicate from the recess 8 to the outer surface of the denture base, preferably the buccal surface, and has a diameter of about 1 mm to 5 mm. . Reference numeral 11 denotes a valve disposed near the outlet of the small hole 10, and is made of a soft elastic material such as rubber. This valve 11 is
As shown in FIGS. 6A and 6B, it has a hollow, substantially conical shape, and is divided into two by a notch 12. Instead of this cut 12, it is also possible to use a dotted microhole. Air and saliva pushed out from the recess 8 spread the valve 11, pass through the notch 12, and are discharged to the outside. Note that when the notch 12 is replaced by a microhole, the microhole is forced open by air and saliva, and the air and saliva are released to the outside through this opening. This valve 11 allows air and saliva to pass only in the direction of the arrow in the figure, and prevents air from flowing back into the recess 8 from the outside. It is preferable that the surface of the valve 11 be a gently curved surface to facilitate cleaning and prevent food particles from adhering to the valve 11. 13 is a cylindrical body made of synthetic resin, for example, the same material as the denture base 3, which forms the small hole 10;
These air vent portions are formed by pushing the cylindrical body 13, on which the valve 11 has been attached in advance, into a hole bored in the elastic member 7.

7 and 8 show another embodiment of the present invention, in which a large number of small holes 14, 14 are formed above the above-mentioned recess 8.
It is covered with a plate member 15 having perforations therein. This plate member 15 is a thin metal plate, a synthetic resin plate,
It is formed of a rubber plate or the like, and has such a springiness that it does not deform even when subjected to the pressing force of the alveolar ridge 5 or the suction force generated in the recess 8 space, or returns to its original shape even if it is deformed. It is something. Note that it is also possible to integrally form the protrusions 9, 9, . . . on this plate member 15. This plate member 15 is configured to be removable from the denture base 3. 10 is the small hole for air vent mentioned above. With such a structure, invasion of the gums into the recess 8 is more reliably prevented.
In the two embodiments described above, a suitable number of small holes 10 are formed, and can be located, for example, at both end portions where they are difficult to see from the outside.

To explain the function of this structure, the elastic member 7 is compressed by the pressure applied to the denture during mastication, and therefore the recess 8 space is also compressed. As a result, some of the air in the recess 8 space is removed from the small hole 1.
0 and valve 11 and is released to the outside. Subsequently, when the pressure applied to the denture 1 is removed, the elastic member 7 returns to its original shape and the recess 8 space increases its volume. This generates a negative pressure within the space of the recess 8, and the denture 1 is fixed to the alveolar ridge 5 with strong suction force. In this way, the air removal action is performed through the small holes 10 every time the chewing action is performed, so the adsorption force increases but never decreases, and the advantage is that a particularly strong adhesion force can be obtained during the mastication action. There is.

9 and 10 show a modification of the embodiment shown in FIGS. 5 and 8, respectively, in which an elastic member 7' is provided only along the peripheral edge of the inner surface of the denture base 3. Even with such a structure, it is possible to achieve substantially the same improvement in adsorption function as in the example described above.

Next, a method for manufacturing a denture according to an embodiment of the present invention will be described in detail using FIGS. 11A to 11L. The illustrated example is the structure shown in FIGS. 4 and 5, and the structure shown in FIG.
This is a method of manufacturing the structure shown in FIG.

(A) A plastic material, such as plaster, is poured into a mold made of an impression of the alveolar ridge in the oral cavity, and is solidified to form a jaw model 16 having a substantially inverted U shape that matches the shape of the alveolar ridge.
On this jaw model 16, a first spacer 17 having the shape of a rubber-like elastic member, which will be described later, is placed on the jaw model 16.
It is placed in close contact with the surface. This first spacer 17 can be made of a metal plate with good moldability, such as lead, or a synthetic resin plate.

(B) After covering the first spacer 17 and pressing wax onto the jaw model 16 to form a pseudo denture base 18, the artificial tooth 2 is implanted onto the pseudo denture base 18.

(C) The artificial tooth 2 is implanted and the pseudo denture base 18 covered with the first spacer 17 is removed from the jaw model 16 and fitted to a predetermined alveolar ridge in the oral cavity for trial use.
Here, the arrangement of the artificial teeth 2, the surface shape of the pseudo denture base 18, etc. are corrected.

(D) The artificial tooth base 18 having the artificial tooth 2 and the first spacer 17 is placed in the flask lower mold 21. This flask lower mold 21 is filled with plaster 20 in a fluid state, and this plaster is brought into close contact with the portion of the pseudo denture base 18 to which the first spacer 17 is attached. After the plaster 20 has solidified, the plaster 20
A separating agent such as soapy water is applied to the surface 19.

(E) Flask upper mold 2 to match flask lower mold 19
Plaster 23 in a fluid state is poured into the lid member 2 made of a metal plate through the upper opening 25.
4 to close the opening 25. plaster 23
After solidification, the entire flask is immersed in hot water for about 5 minutes to soften and melt the pseudo denture base 18 made of wax.

(F) After separating the upper and lower flask molds 21 and 22 and letting the wax flow out, a mold release agent is applied to the plaster surface of this outflow space, and a cake-shaped synthetic resin material such as polymethyl methacrylate is applied to the space. Fill the resin 26.

(G) The upper and lower flask molds 21 and 22 are immersed in hot water for about 1 hour in a pressed state to heat the molds, thereby hardening the polymethyl methacrylate resin and forming the denture base 3.

(H) After cooling, remove the flask upper mold 22, polish the surface of the denture base 3, and then remove the first spacer 17.
Wax 2 on the lower end of the denture base 3 where
Apply 7. This wax 27 is the denture base 3
It slightly covers the lower edge and seals the joint between the denture base 3 and the plaster part. A separating agent is applied to the plaster surface 21.

(I) The flask upper mold 22 is superimposed on the flask lower mold 21, fluidized gypsum 28 is poured into it, and the lid member 24 is pressed. At this time, small holes 29 communicating with the wax 27 are formed at the same time.

(J) After the plaster 28 has solidified, the flask is immersed in hot water to separate the upper and lower molds 21 and 22, and the wax 27 is removed by flowing out. Thereafter, the flask is taken out of the hot water, the first spacer 17 is removed from the denture base 3, and the inner surface of the denture base 3 is subjected to cleaning treatment such as polishing.

(K) Concavity 8 on the top of the plaster mold 20 of the flask lower mold 21
The second spacer 30 having the shape is fixed, the upper and lower flask molds 21 and 22 are overlapped, and the small hole 29 is
Then, a rubber-like elastic material such as urethane resin is melted and injected into the space where the first spacer 17 was present. Press molding may be used instead of this injection. Here, the second spacer 30 is made of a metal plate or the like, which has a thinner periphery and has a large number of recessed holes.

(L) After curing rubber-like elastic member 7, flask upper and lower molds 2
1 and 22 are separated, the plaster 20 and 28 portions are broken, and the denture 1 is taken out. At this time, the second spacer 30 is simultaneously peeled off, and a recess 8 having a large number of convex portions is formed on the inner surface of the elastic member 7. 15 is a plate member that covers this recess 8 and is prepared separately. Following this process, a small hole 10 communicating between the outer surface of the denture base and the recess 8 is bored in the denture base 3, and a valve 11 (FIG. 6) is formed in the small hole 10. Through the above steps, the denture base 1 according to the present invention is completed.

In each of the above-mentioned embodiments, a denture for the lower jaw has been described, but it goes without saying that the same structure can be adopted for a denture for the upper jaw as well as a local denture.

Further, when the height of the alveolar ridge is uneven, it is difficult to form a recess because the denture base corresponding to the protrusion becomes thin, but in such a case, it is sufficient to form a recess in the alveolar ridge recess. However, when the recesses are formed separately, it is preferable that they be communicated with each other by a thin groove or the like to equalize the suction force between the two. The above-mentioned unevenness of the alveolar ridge is caused by, for example, immediately after a tooth is extracted, the alveolar ridge is thicker or higher because the alveolar bone remains; This occurs because the alveolar ridge has become lower due to the receding of the alveolar ridge.

Effects of the Invention According to the present invention, the space formed between the recess provided inside the denture base and the alveolar ridge is compressed with mastication, and as a result of this compression, the air inside the space is forced into small pores. and is pushed out through the valve. Therefore, when the space compression is removed, the negative pressure in the space increases, which significantly increases the adhesion of the denture to the alveolar ridge. In addition, since the gingival intrusion prevention means consisting of a convex portion and/or a plate member is provided in the recess, there is no fear that the denture will intrude into the recess, and a stable adsorption force can be maintained for a long period of time. can.

Further, according to the present invention, since the inner surface of the denture base is composed of a rubber-like elastic member, this elastic member is slightly compressed by the pressure applied to the denture during mastication, and the volume of the recessed space is greatly increased or decreased. A large adsorption force can be obtained. Particularly in the case of dentures that are fitted into the upper jaw, conventionally it has been common to have a palate that covers the entire surface of the upper jaw in the oral cavity in order to increase the suction area, but according to the present invention, the suction force to the alveolar ridge is increased. Because it is strong, there is little risk of it falling off due to its own weight or movement during mastication, so the roof of the mouth is unnecessary and the foreign body sensation is eliminated.

Furthermore, when the present invention is applied to a local denture, the clasp (retention hook) becomes unnecessary due to the enhanced adsorption force. Traditionally, this clasp is attached to hook teeth,
In some cases, dentures were broken or damaged due to the excessive force applied to them, but according to the present invention, there is no stress on the hooked teeth, eliminating the fear of shortening their lifespan, and at the same time improving aesthetics. It will be planned.

Normally, after half of the time, the shape of the alveolar ridge and jaw changes due to recession, etc., and the fit to the denture base deteriorates, but if the denture is continued to be used in such an unfitted state, the jaw and alveolar ridge will recede due to the tapping effect. The deformation is further accelerated, resulting in the disadvantage that the entire denture must be remade. On the other hand, according to the present invention, since the denture is stabilized, deformation due to recession as described above can be suppressed to a minimum, and the fitting state of the denture can be maintained for a long period of time. Furthermore, according to the present invention, even if the alveolar ridge is slightly deformed, only the rubber-like elastic member is peeled off and re-impressed in the oral cavity, and a rubber-like elastic member that matches the shape of the alveolar ridge is attached to the inner surface of the denture base. Since it can be adhesively formed, there is an economical advantage that most of the dentures can be used continuously.

[Brief explanation of drawings]

Figure 1 is a perspective view showing a typical shape of a denture, Figure 2 is a sectional view of Figure 1, and Figures 3A and B are
4 is a perspective view of the embodiment of the present invention; FIG. 5 is a sectional view of FIG. 4;
FIG. 6A is an enlarged plan view of the main part, FIG. 6B is an enlarged sectional view of the main part, FIG. 7 is a perspective view of another embodiment of the present invention, and FIG. 8 is a sectional view of FIG. 7. , FIG. 9 and FIG. 10 are sectional views of main parts, and FIG. 11 A to L
2A and 2B are cross-sectional views showing the manufacturing method of the example in order of steps. 1... Denture, 2... Artificial tooth, 3... Denture base, 5
...Alveolar ridge, 7,7'...Rubber-like elastic member, 8...
...Concavity, 9,9...Protrusion, 10...Small hole, 11...
...Valve, 15...Plate member, 16...Jaw model, 17...
...First spacer, 18...Pseudo denture base, 21...
Flask lower mold, 22... Flask upper mold, 20,2
3, 28...Gypsum, 30...Second spacer.

Claims (1)

[Scope of Claims] 1. A denture having an artificial tooth and a denture base to which the artificial tooth is fixed, wherein the denture base has a recess formed on its inner surface so as to form a sealed space between it and the alveolar ridge mucosal surface. A small hole communicating from the recess to the outer surface of the denture base, a valve means formed in the small hole to allow air to pass only from the recess to the outer surface of the denture base, and preventing gingiva from entering the recess. gingival invasion prevention means to prevent;
A denture comprising a rubber-like elastic member that covers at least the peripheral edge of the inner surface of the denture base. 2. According to claim 1, the gingival intrusion prevention means is constituted by a convex portion provided in the recess to form an uneven surface on which the gingiva cannot be deformed along the wall. dentures. 3. The above-mentioned gum invasion prevention means is constituted by a plate member having a plurality of small holes, which covers the above-mentioned recess and forms a space between the recess and the recess. Dentures according to scope 1. 4. The gingival invasion prevention means includes a convex portion provided within the recess to form an uneven surface that prevents deformation of the gingiva along the wall, and a convex portion that covers the recess and forms a space between the recess and the recess. 2. The denture according to claim 1, wherein the denture is made of a removable plate member having a plurality of small holes. 5. The solubility parameter value of the rubber-like elastic member is set to be substantially equal to the solubility parameter value of the denture base, and the rubber-like elastic member is fused and fixed to the denture base. The denture according to claim 1. 6 Forming a jaw model with a shape that matches the alveolar ridge shape using a plastic material such as plaster; After covering the jaw model with a first spacer having a predetermined thickness, wax is applied onto the first spacer. Forming a pseudo denture base and arranging artificial teeth on the pseudo denture base; Covering the artificial teeth, the pseudo denture base and the first spacer with a plastic material, and applying heat treatment etc. to form a pseudo denture base made of the wax. a step of filling the wax removal space with a denture base forming material such as a synthetic resin to form a denture base; removing the first spacer and arranging the second spacer in the recess forming area; A step of injecting a molten rubber-like elastic member into the first spacer space and then curing it to form a rubber-like elastic member having a recess that is adhered to the inner surface of the denture base; A method for manufacturing a denture, comprising: providing a small hole communicating between the outer surface and the recess, and forming a valve means in the small hole.