JPS6129348A - Formation of lining material of denture - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention can provide support to the alveolar ridge with a stable and flexible feel, thus preventing wobbling or involuntary tenderness during mastication. The present invention relates to a method for forming a denture lining material.

<Prior Art> Conventionally, it is already known to provide an elastic member on the inner surface of a denture base to improve adhesion to the alveolar ridge. For example, Japanese Unexamined Patent Publication No. 48-29295 discloses a denture base in which a plasticizer is mixed with a polymeric material and the mixture is formed as a lining material on the inner surface of the denture base. However, such a structure is close to a sponge structure and is essentially different from a rubber-like elastic body. Further, there is a problem in that the material gradually hardens due to elution of the plasticizer, and sufficient elasticity cannot be obtained. Furthermore, a device using a rubber material as a lining material is disclosed in Japanese Patent Application Laid-Open No. 55-26923, but it is usually difficult to bond a rubber material to a denture base, so such an integral structure of a denture and a rubber material is not possible. cannot be obtained easily.

<Problems to be Solved by the Invention> When a lining material is formed by heating and melting a thermoplastic elastomer that is highly compatible with the high-temperature material constituting the denture base and pressing it against the inner surface of the denture base, the lining material after cooling is The adhesive strength of the material to the denture base tends to become weaker toward the edges. In order to weld the heated and melted thermoplastic elastomer to the denture base, the temperature must be above a predetermined temperature.On the other hand, if the heating temperature is too high, it will deteriorate and change its physical properties, so the heating temperature range is limited. There is a problem that temperature control is difficult due to the high temperature. In other words, the lining material has an extremely thin film thickness of about 0.5 to 1.0 yen, and even if thermoplastic elastomer heated and melted at a predetermined temperature is injection molded, as it flows into the lining material forming space, This will cause the edges to peel off easily.

The present invention solves these problems by suppressing the temperature drop at the edge of the lining material and improving the adhesive strength in this area.

<Means for Solving the Problems> The present invention makes the portion corresponding to the edge of the lining material larger than other portions of the lining material forming space formed by a plaster mold, and therefore this The amount of heated and molten thermoplastic elastomer flowing into the section is increased.

<Function> Since a large amount of thermoplastic elastomer melt flows into the large space at the edge of the lining material forming space, the temperature drop in this area is suppressed, and therefore the lining material maintains a denture with approximately uniform strength over the entire surface. Glue to the floor.

Embodiments FIG. 1 shows a method for forming a denture lining material according to the present invention in the order of steps, and will be described below with reference to the figures below.

(A) A flask (1) is filled with plaster (2) in a fluid state to form a jaw model (3). After the plaster (2) hardens, a wax pattern (4) having the shape of a denture base is formed on this jaw model (3), and artificial teeth (5) are arranged on this wax pattern (4). Ru.

(B) Another flask (6) is placed on top of the flask (1) and filled with fluidized gypsum (7). ” (C) After the plaster (7) has solidified, the flask (1)
(6) is removed and the wax pattern (4) is removed by washing with hot water. At this time, the artificial tooth (5) is made of plaster (
7) Remains buried within.

Thus, a recess (8) is formed in the plaster (7) that matches the surface shape of the denture base.

(D) The recess (8) is filled with an appropriate amount of alginate impression material (9). On the other hand, on the surface of the jaw model (3) made of plaster (2), -
・Wax layer with constant thickness (approximately 0.5■■)
is formed by coating.

(E) Flasks (1) and (6) are stacked and pressed together. As a result, alginate impression material (9) becomes wax 1! (10) It is formed into the shape of a denture base excluding the part.

Afterwards, the flasks (1) and (6) are filled with wax J! (10
) and the impression material (9).

(F) the flask (6) containing the impression material (9) is inverted;
Another flask (1)) is placed on top of the other and filled with fluidized plaster (12). This allows I! Model (3
) with a wax layer (10) added thereto. Another jaw model (13) is formed. After the plaster hardens, both flasks (6
)(1)) is removed and the alginate impression material (9) is removed.

(G) The recess (8) is filled with polymethyl methacrylate (14) formed into a rice cake shape by adding a crosslinking agent to polymethyl methacrylate powder and mixing with liquid methyl methacrylate monomer.

(I() Then both flasks <6) (1))
The stacked and pressed state is immersed in a vortex at about 100° C. for about 30 minutes. As a result, polymethyl methacrylate (14) is polymerized (crosslinked) and solidified, and the denture base (15) is solidified.
) is formed. At this time, the artificial tooth (5) is simultaneously fixed to the denture base (15).

(1) When the polymerization is completed, the flask (6) (1)) is released and the denture base (15) is placed on the jaw model (3) of the flask (1) used in the above step (E). Wax layer (
10). A wax layer (10) is formed around the end of the denture base (15).
) Extends to the lower end of the outer surface (in the figure). Further, a thick portion (16) is formed at the edge of this wax layer (lO). This thick portion (16) can be formed by welding rod-shaped wax having a diameter of about 2 to 3 nm. A sprue (
17) is made of wax.

(J) Above the above flask (1), put another flask (18
) are superimposed and fluidized plaster (19) is poured. (20) is molded in wax with a Paris groove.

(K) After the plaster hardens, the flasks (1) and (1B) are separated, and the wax layer (IO) and the wax on the sprue (17) are washed with hot water and removed.

(L) An adhesive (21) prepared by dissolving polymethyl methacrylate in tetrahydrofuran as a solvent is applied to the surface of the denture base (15).

Note that this adhesive (21) does not contain a polymethyl methacrylate crosslinking agent.

(M) Adhesive (21) After drying, both flasks (1) (18
) is heated to about 70°C to 80°C in a constant temperature bath and then stored in the vacuum chamber (22). Flask (1) (18)
is held from the flask injection hole (23) while maintaining a micro gap of about 1 mm (approx. 5 mm).
A thermoplastic urethane elastomer (24) heated to about 212° C. and melted is injected. Immediately after this injection, the flasks (1) (18) are clamped. In this way, the molten elastomer (24) that has flowed in the horizontal direction in the figure due to injection flows in the vertical direction in the figure due to the clamping after injection.

(N) After the urethane thermoplastic elastomer (24) has cooled, the plaster mold is removed from the flask (1) (1B), the plaster mold is destroyed, and the denture (25) is taken out.The denture base ( 15) Lining material (26) formed on the inner surface
) is formed with a thick edge.
4 Delete from i at t<-(27).

(0) In this way, the lining material (26) is firmly bonded to the inner surface of the denture base (15).

FIG. 2 shows the appearance of the completed denture (25). Although the edge portion a of the lining material (26) is extremely thin, its adhesion to the Il tooth base (15) is good.

In the above example, the case where adhesive 1s (10) was applied in advance to the inner surface of the denture base (15) prior to injection of the urethane-based thermoplastic elastomer (24) was explained, but as will be described later, polymethyl methacrylate Since the urethane thermoplastic elastomer has good compatibility, it is possible to obtain a practically acceptable adhesive strength without necessarily using the adhesive (10).

In the above step (M), the injection and clamping of the molten elastomer (24) is performed under a vacuum atmosphere in order to prevent air bubbles from being mixed into the molten elastomer (24).

According to experiments conducted by the inventors, the adhesion between the thermoplastic urethane elastomer (24) and the denture base (15) made of polymethyl methacrylate resin was determined when the temperature of the thermoplastic urethane elastomer (24) was 212°C ± It has been confirmed that the optimum temperature is within the range of 5℃. That is, below this temperature range, it is easy to peel off, and above this temperature range, the urethane thermoplastic elastomer deteriorates and is therefore inappropriate.
When molding a l1 layer with a thickness of approximately
Even if the denture is embedded in the plaster, it flows into the distal end (as the temperature decreases to below 207°C, making it easy to peel off.) There are ways to prevent the temperature from dropping, but since gypsum contains crystallized water, it is impossible to raise the temperature above 100℃, and the temperature is at most 70℃.
℃ to about 80℃.

Therefore, it is not possible to improve adhesion only by heating plaster. For these reasons, in the present invention, the edge of the lining material (26) forming space is made larger and combed, and the amount of molten elastomer (24) flowing therein is increased to suppress the temperature drop. There is. In addition, suppression of this temperature drop can be further improved by injecting the molten elastomer (24) with the flasks (1) and (18) open. Explain about gender. When polymethyl methacrylate resin is used as the material for the denture base (15), a urethane thermoplastic elastomer is suitable. This is because polymer materials generally have extremely good compatibility between materials whose solubility parameters (hereinafter referred to as sp values) are the same or similar, and by melting and adhering one to the other, it becomes stronger. This is because adhesive strength can be obtained. In this example, the sp value of the polymethyl methacrylate resin is 9°3 to 9.9, and the sp value of the urethane thermoplastic elastomer is 1000, so the inner surface of the denture base (43) (alveolar ridge contact surface) A thermoplastic urethane elastomer heated and melted at about 212° C. may be injected and pressed. If you do this,
The urethane thermoplastic elastomer is easily and firmly bonded to the denture base (43).

In addition, if you want to obtain even stronger adhesive strength, use tetrahydrofuran (sp, 419.9) as a solvent and dissolve a polymer of methyl methacrylate in it to create an adhesive prepared using polymethyl methacrylate. The urethane thermoplastic elastomer may be applied to the inner surface of the denture base (15) made of acrylate resin, evaporated the solvent, and then heated and melted, followed by injection molding. In this way, the polymer of methyl methacrylate contained in the adhesive will polymerize into the polymethyl methacrylate that is the denture base (15), resulting in extremely strong adhesive strength. In addition, similarly strong adhesive force can be obtained when a urethane-based thermoplastic elastomer is melted into the above-mentioned adhesive. This is because the thermoplastic urethane elastomer contained in the adhesive and the thermoplastic urethane elastomer that is heated and melted and brought into contact with it are fused and bonded. .

In addition, as a solvent for the adhesive, the above-mentioned Tetrahytrowa, 2O
, Yoka 1, Acetic Egaya (3, value 9.1), Ura
ilohexanone (sp value 9.9) and the like are also suitable. These adhesives can be used with denture base materials other than chilimethyl methacrylate resin, such as the aforementioned polyethersulfone (sp value 9.7 to 9.9 >), polysulfone (s, p value 9.5 to 10.7), Can also be used on polycarbonate (sp value 9.8).

<Effects of the Invention> The present invention was formed using a plaster mold. Since the edge part of the lining material forming space is expanded and the amount of molten elastomer flowing into this space is increased, the temperature drop of the molten elastomer at the edge part is suppressed, and therefore the lining material in this area is suppressed. can improve the adhesive strength of

In addition, by allowing a large amount of molten elastomer and mer to flow into the expanded space, injection errors such as not filling can be prevented.
Can be reliably molded.

[Brief explanation of drawings]

FIGS. 1(A) to 1(0) are cross-sectional views illustrating an embodiment of the present invention in the order of steps, and FIG. 2 is a perspective view of a completed product. (1) (6) (1)) (18)... flask (2
) (7) (12) (19)...Gypsum (3), (13)
)... Jaw model (4)... Wax pattern (5)... Artificial tooth (9)... Impression material (1o)... Wax layer (14)... Polymethyl methacrylate (15 )
... Denture base (16) ... Thick part (21) ...
・Adhesive (24)...Urethane thermoplastic elastomer (26)
)... Lining material

Claims (1)

[Claims] (1) Step of forming a denture base with arranged artificial teeth by molding a polymeric material; forming a wax layer of a predetermined thickness on the inner surface of the denture base, and forming thick edges of the wax layer. Step: After embedding the denture including the wax layer in plaster and taking a mold of the denture, removing the wax layer; Adding a denture base polymeric material compatible with the denture base polymeric material in the wax layer removal space of the plaster mold. Filling with a thermoplastic elastomer that has been melted by heating and bonding the thermoplastic elastomer to the inner surface of the denture base; After the thermoplastic elastomer has cooled, the denture is removed from the plaster mold, and the lining material made of the thermoplastic elastomer is A method for forming a denture lining material, comprising at least the step of removing a thick edge portion;