JPH0247214B2 - GISHISHOOYOBISONOSEIZOHOHO - Google Patents

Description

[Detailed description of the invention]

<Industrial Application Field> The present invention relates to a denture base provided with a lining material having rubber elasticity and a method for manufacturing the same. <Conventional technology> Conventionally, in order to provide stable and strong support to the alveolar ridge and prevent wobbling during mastication, involuntary tenderness, and falling off, rubber elastic or flexible lining materials have been attached to the denture base body. It is known that it forms on the alveolar ridge contact surface. As the material for such backing material, soft fluororesin is used (Japanese Patent Application Laid-Open No. 1983-1999).
No. 21919), those using collagen (Special Publication No. 1987),
-50498), those using silicone rubber (Japanese Patent Application Laid-Open No. 58-54946), those using natural rubber and isoprene polymer (Japanese Patent Application Laid-open No. 55-26923), styrene,
There is one that uses a butadiene-based thermoplastic elastomer (Utility Model Application Publication No. 101622/1983). <Problems to be Solved by the Invention> When the above-mentioned materials are used as the lining material, the following problems occur. In the case of soft resin, its rubber elasticity is limited, making it unsuitable for maintaining attachments, and when it is deformed by local pressing force, it does not have the same restoring force as rubber. If the thin sheet is pressed against the mucosal surface of the denture base, it is difficult to fill the undercut portion of the natural tooth, and sufficient retention force cannot be obtained. Since silicone rubber is a vulcanized rubber, it is difficult to modify it once it has been vulcanized and molded. The present invention was made in view of these circumstances, and by using a new thermoplastic elastomer as the lining material, it is possible to create a lining that is easy to mold and modify without the need for special machinery. This material was realized. <Means for solving the problems> In the denture base according to the present invention, the lining material is an olefin thermoplastic elastomer or a copolymer of an olefin thermoplastic elastomer and styrene-ethylene-butylene (hereinafter referred to as SEBS). The lining material is made of a mixed material of thermoplastic elastomer, and the lining material is made of polymethyl methacrylate (hereinafter referred to as PMMA) resin. It uses an adhesive containing a copolymer. Moreover, the denture base manufacturing method according to the present invention includes the following steps. That is, first, the lining material, heated and softened, is sandwiched between plaster molds having a lining material forming space and pressed together to obtain a lining material of a predetermined shape. Next, apply the above adhesive to the surface of the lining material, and after it dries,
PMMA powder was mixed with liquid MMA monomer and made into a rice cake shape in a plaster mold with a denture base forming space.
PMMA is filled and compressed, and this is heated to about 100℃ or
Place in hot water or steam at 130℃. In this way, the rice cake-like PMMA is polymerized and solidified to form the denture base body, and at the same time, the lining material is bonded and integrated with this body. <Example> (a) Complete denture Figure 1 shows an example of the case where it is adopted as a mandibular complete denture 1. In the figure, 2 is the denture base body made of PMMA resin, and 3 is the alveolar ridge mucosal surface of the denture base body 2. 4. A rubber elastic backing material adhered to a thickness of about 0.5 mm to 1.5 mm on the entire surface facing the 4.
4... are artificial teeth fixed to the denture base main body 2. Here, the following materials are used for the lining material 3 and its adhesive. (b) Backing material The third material for the lining material is an olefin-based thermoplastic elastomer containing at least polyethylene or polypropylene, or an olefin-based thermoplastic elastomer.
A mixed material of thermoplastic elastomer consisting of SEBS copolymer is used. A hard segment made of polyethylene or polypropylene as an olefin thermoplastic elastomer,
Those consisting mainly of soft segments of homopolymers or copolymers of butene, propylene, butadiene, etc., or those consisting mainly of soft segments consisting of copolymers of polyethylene and polypropylene can be used, and these have a softening temperature of 100°C or less. Temperature and JIS hardness (hereinafter simply referred to as hardness)
It has a wide range of hardness from about 20 to 90.
As this kind of olefin-based thermoplastic elastomer, Tafmer (registered trademark) manufactured by Mitsui Petrochemical Co., Ltd. is suitable; the former is called Tafmer (registered trademark) A, and the latter is called Tafmer (registered trademark).
It is commercially available as P. The above Tafmer (registered trademark) A is an α-olefin thermoplastic elastomer, and there are some that contain either polyethylene or polypropylene alone as a hard segment, and others that contain both polyethylene and polypropylene, and its hardness is approximately From 20 to over 90. By blending the above two types of thermoplastic elastomers, the hardness can be adjusted within the usable range of about 40 to 80. The above olefin thermoplastic elastomer is
Since it begins to soften at around 70°C, a thermoplastic elastomer made of SEBS copolymer can be blended with an olefinic thermoplastic elastomer to improve its temperature characteristics. Also, this
SEBS-based thermoplastic elastomers have better shape retention against temperature changes than olefin-based thermoplastic elastomers, so combining the two improves overall durability. This kind of SEBS-based thermoplastic elastomer is obtained by hydrogenating a styrene-butadiene-based thermoplastic elastomer, and for example, Lavalon (registered trademark) manufactured by Mitsubishi Yuka Corporation can be used. FIG. 2A shows the hardness-temperature characteristics when the mixing ratio of the olefin thermoplastic elastomer and the SEBS thermoplastic elastomer is varied. In the figure, the numerator indicates the proportion of the olefin thermoplastic elastomer, and the denominator indicates the proportion of the SEBS thermoplastic elastomer. As is clear from the figure, increasing the mixing ratio of SEBS-based thermoplastic elastomer suppresses softening from around 70°C. Furthermore, if the SEBS thermoplastic elastomers have different hardnesses, the hardness will change upon mixing, so the hardness can be adjusted by this. However, since increasing the amount of SEBS thermoplastic elastomer reduces the adhesive strength to the denture base body, the actual mixing ratio is approximately 75%.
It is necessary that the following is true. As mentioned above, the olefin-based thermoplastic elastomer itself begins to soften rapidly at around 70°C, but most of the lining material is between the denture base body and the alveolar ridge mucosal surface and is shielded from the outside. However, it is unlikely that this material will be heated to around 70℃, and the temperature around the lining material that is exposed in the oral cavity may reach instantaneously, but the more it softens and deforms, the more The temperature is not maintained, and in practice, the olefin thermoplastic elastomer alone can be used. When a single olefin thermoplastic elastomer is used, its hardness can be adjusted by mixing Tafmer (registered trademark) A and P and changing the mixing ratio. FIG. 2B shows the hardness-temperature characteristics when the mixing ratio of TAFMER (registered trademark) A and P is changed. In the figure, the numerator indicates the proportion of TAFMER (registered trademark) A4085 (product number), and the denominator indicates the proportion of TAFMER (registered trademark) P680 (product number). Tafmar (registered trademark) A
has excellent compressive strength, but since it is hard when used alone, it is blended with soft Tafmer (registered trademark) P.
Set the hardness to an appropriate value (for example, a blend ratio of 1:1)
In this case, the hardness is adjusted to about 70) at 37℃. It is possible to mold the lining material 3 at a temperature of approximately 70° C. or higher. It can therefore be heated in hot water, steam, higher alcohols, edible oils or by infrared radiation and also using an electric oven. In particular, since edible oil can be heated to about 200° C., the fluidity of the lining material 3 is further improved when heated to such a temperature. Therefore, it is also possible to put it in a tube or the like to form a lump and heat it. The hardness of the lining material 3 is preferably at least two types, hard and soft, depending on the location where it is used, with a hard one having a hardness of about 70 and a soft one having a hardness of about 50.
It is sufficient to set it to a certain degree. Next, test results regarding the safety of the material of the lining material 3 according to this example will be explained. In the test, two types of samples M1 and M2 were prepared, and they were placed in the actual usage condition, that is, a PMMA denture base (using GC Acron (registered trademark, manufactured by Jishi Dental Industry Co., Ltd.)) was coated with the adhesive described below. It was done with the parts glued together. Here sample M1
is a material in which Tafmer (registered trademark) A4085 and Lavalon (registered trademark) MJ6300 (product number) are blended in a 1:1 ratio, and sample M2 is a material in which Tafmer (registered trademark) A4085 and P680 are blended in a 1:1 ratio. It is a blended material. Safety test) Primary skin irritation test The eluates of samples M1 and M2 were applied to the skin of rabbits, respectively, and their irritation was examined according to the Draize criteria. As a result, no primary skin irritation was observed due to the application of samples M1 and M2 eluates, and it was determined that the skin irritation was negative. ) Acute toxicity test Using 6-week-old male and female SD rats, sample M1
An acute toxicity test was conducted on M2 eluate and 1 oral administration followed by observation for 14 days. As a result, there were no cases of death in either sex after administration of 50 ml/Kg, which is close to the administration limit, and no abnormalities were observed in the animals' general condition, body weight changes, or autopsy. ) Extractable substance test Samples M1 and M2 were extracted by incubation with distilled water at 70°C, and the ultraviolet absorption spectra were measured.
Analysis was performed based on absorbance at 220 nm. The dissolution properties of sample M1 were determined by the silicone rubber lining material Silastic (registered trademark) (manufactured by Dow Corning) and the polyvinyl chloride lining material Tygon (registered trademark).
(manufactured by Norton Plastic Synthetics) and GC Akron (registered trademark), a PMMA resin for denture bases, but it is presumed to be within a range that has no effect on living organisms. In sample M2, the fluorine resin lining material Kurepeet (registered trademark) (manufactured by Kureha Chemical Industry Co., Ltd.) and the silicone rubber lining material MOLLOPLAST (registered trademark) (manufactured by Moroplast Kagey Co., Ltd.) were used. The eluate was extremely small compared to the two. Also, the sample
It was found that there was almost no eluate in M2 alone (that is, excluding the denture base part). ) Hemolysis test When we conducted a hemolysis test on sample M1, the hemolysis rate of sample M1 after 24 and 48 hours was almost the same as that of Tygon (registered trademark), and better results than GC Akron (registered trademark) were obtained. Ta. Furthermore, the degree of hemoglobin denaturation after 24 and 48 hours was almost the same as that of GC Akron (registered trademark). In sample M2, both the hemolysis rate and the degree of hemoglobin denaturation after 24 and 48 hours were approximately the same as those of GC Akron (registered trademark), Silastik (registered trademark), and Tygon (registered trademark). In particular, the hemolysis rate of sample M2 alone (that is, excluding the denture base portion) was 0, which was the lowest among the comparative samples. ) Cytotoxicity and biocompatibility test The cytotoxicity and biocompatibility of samples M1 and M2 were tested using both HelaS3 and Flow7000 cells. As a result, sample M1 did not show toxicity to Flow7000, but showed weak toxicity to Hela cells. That is, in the cytotoxicity test, the cell proliferation rate in the group to which 4000 mg/20 ml extract of sample M1 substance was added was 75% of the control;
In the 7-day cell proliferation test on M1 material, the proliferation rate was 65% of the control;
Weak toxicity was observed in M1. However, cell culture methods are generally more sensitive than animal experiments, so even if some toxicity is observed in cell culture, unless the polymer material used is decomposed in the living body or has an electric charge, Generally, it shows almost no toxicity in animal experiments.
Regarding sample M1, only weak toxicity was observed in the cell culture method, so it is presumed that almost no toxicity was observed in animal experiments. Similar HelaS3 and
As a result of testing using both Flow7000 cells, both cells showed almost no toxicity. Physical Property Test) Wettability In order to estimate the wettability with saliva, the contact angle with water was measured using a precision contact angle measuring device model CA-1 (manufactured by Kyowa Kagaku Co., Ltd.).

[Table] However, the above data is obtained for a sample whose surface was dried after being immersed in distilled water at 50°C for 24 hours. As is clear from the table, it is superior to the commercially available silicone backing materials Moroplast (registered trademark) and Neos Natsuga (registered trademark) (manufactured by Neo Pharmaceutical Industries Co., Ltd.). ) Discoloration The lining material 3 may discolor due to food during use of the denture in the oral cavity. In order to examine the discoloration of the lining material from the viewpoint of maintaining its aesthetics, a discoloration test was conducted using an aqueous solution of turmeric, which is thought to contribute most to discoloration in food systems. A commercially available lining material was used as a comparison sample. Test conditions: 37℃ turmeric 1.0gr/immersed in aqueous solution for 24 hours, washed with water, and measured with a color difference meter.
The Δ ^* Eab value in the CIE1976 color system was quantified using CR-100 (manufactured by Minolta Camera Co., Ltd.).

[Table] From this table, sample M2 has approximately the same degree of discoloration as Crepate (registered trademark), sample M1,
For both M2, Neos Natsuga (registered trademark) and Moroplast (registered trademark) acrylic backing material Super Soft (registered trademark) (COE)
It can be seen that it is smaller than the one manufactured by the company. ) Stress Relaxation In order to evaluate the degree of permanent deformation of the lining material in the oral cavity and its safety as an elastomer against water, stress relaxation was measured in water at 50°C. The experiment was performed in a linear behavior region with a strain rate of approximately 5%, and data was analyzed from changes in relative stress over time. The following table shows quantitative values of the stress relaxation rate constant K in water at 50°C.

[Table] As a result, it can be seen that for samples M1 and M2, the change in rubber elastic modulus is small over a long period of time, and flow deformation and molecular structure changes are unlikely to occur in 50°C water. ) Elastic modulus The elastic modulus (Young's modulus) was measured as a coefficient that indicates the softness of the lining material in the oral cavity.

[Table] Crepate (registered trademark) is a little too hard,
On the other hand, Moloplast® and Neosnazgar® are too soft. (c) Adhesive The olefin-based thermoplastic elastomer used as the third material for the lining material is composed mainly of non-polar saturated hydrocarbon compounds, so as mentioned above, it is extremely stable physically and chemically in the oral cavity. Although this type of material is ideal as a denture lining material, its chemical stability makes it difficult to adhere to denture bases, which are made of different polymeric materials. Such difficulties have not yet been overcome even in the polymer chemical industry. The adhesive according to the present invention solves this problem. That is, the adhesive for bonding the lining material 3 to the denture base main body 2 made of PMMA contains a copolymer of olefin and MMA, specifically a copolymer of polyethylene and MMA. ) Manufacturing method: Polyethylene is heated and dissolved in toluene in a polymerization reactor, and a predetermined amount of MMA and benzoyl peroxide (hereinafter referred to as "radical polymerization initiator") are added as a radical polymerization initiator.
BPO) was added and graft polymerization was performed at 70°C under a nitrogen atmosphere. After 4 hours of polymerization, the polymerization solution was poured into a large amount of poor solvent (methanol in this example).
The polymer was separated by precipitation. PMMA
The separation of MMA and MMA monomers was carried out with ethyl acetate using a Soxhlet extractor. 8
Time extraction was performed to dissolve and remove PMMA and MMA. As a result of analyzing the graft copolymer thus produced by infrared spectroscopy and other analysis methods, it was confirmed that the desired molecular structure was obtained. The following table shows the degree of polymerization, degree of grafting, and grafting efficiency of three types of polyethylene-MMA graft copolymer products A, B, and C with varying BPO concentrations.

[Table] The unit of BPO concentration is ×10 ^-3 mol/, and the degree of grafting and grafting efficiency are values calculated using the following formula. Grafting degree % = Grafted monomer amount / Stem polymer amount × 100 Grafting efficiency % = Grafted monomer amount / Polymerized monomer amount × 100 The graft copolymer obtained as described above was added to 1.1.1. trichloroethane. It was dissolved to form a liquid adhesive. 1.1.1. Trichloroethane used as a solvent is non-toxic and has a boiling point.
It is suitable as this type of solvent because it evaporates easily at 74.1°C. In addition, chloride-based organic solvents such as chloroform, toluene, xylene, ethers, etc. can be used as the solvent. FIG. 3 shows the analysis results of copolymer product B by a differential thermal analyzer. The melting point of copolymer product B was thereby determined to be approximately 118°C. This means that copolymer product B
Apply the adhesive to the lining material and make it into a rice cake shape.
This means that when PMMA is pressure-welded and polymerized and solidified by heating to approximately 100℃ to 130℃, the above-mentioned copolymer product is dissolved, and this is said to generate adhesive function and improve its effect. Guessed. In fact, it was confirmed that when the bonding time is increased, the bonding function occurs even at about 100°C due to a relaxation phenomenon. ) Adhesive strength As shown in Figure 4, backing material 3 with a thickness of approximately 0.7 mm
After applying the adhesive 5, 5 prepared by the method described above to both sides of the material and thoroughly drying it,
PMMA powder is kneaded with liquid MMA monomer to form a rice cake, and PMMA is placed on both sides of the backing material 3, and the PMMA is polymerized and solidified by applying pressure and heating.
6 is formed, and at the same time polymerization adhesion is performed with the backing material 3 material made of sample M1. After adhesion, a test piece 7 of 10 mm x 10 mm was prepared, and the adhesive strength was measured by pulling it at a speed of 50 mm/min in the direction of the arrow in the figure using Autograph (registered trademark) DSS-5000 (manufactured by Shimadzu Corporation). The following table shows the measured values for the aforementioned copolymer products A, B, C and commercial products D, E. In addition, commercial product D
is Moroplast (registered trademark), and commercial product E is
Crepate (registered trademark) and adhered according to the instructions for use.

[Table] As is clear from the table, when the above-mentioned lining material was polymerized and bonded using the adhesive in this example, an adhesive force of 60 kg/cm was obtained (adhesive B),
Such strength is practically sufficient. Similarly, when sample M2 was polymerized and bonded using adhesive B, an adhesive strength of 80 kg/cm ² was obtained. In addition, when the adhesive was applied after polymerization and curing of the PMMA resin plate and the backing material was heat-pressed (using adhesive B), the weight was 41 kg/cm ² for sample M1 and 41 kg/cm 2 for sample M2.
An adhesive strength of 60 Kg/cm ² was obtained. (d) Other adhesives Polypropylene is used instead of polyethylene, and MMA is polymerized with it under the same conditions as the polymerization method described above (conditions for product B) to produce a graft copolymer of polypropylene and MMA. An adhesive was prepared by dissolving this in a solvent consisting of ortho-xylene. Using such adhesive, the sample
Glue the backing material made of M1 and the PMMA resin plate,
As a result of the same tensile test as above, the result was 38Kg/cm ²
obtained the value of This allows polypropylene and
It can be seen that even when an MMA copolymer is used as an adhesive material, adhesive strength that can withstand practical use can be obtained. Furthermore, the above-mentioned TAFMER (registered trademark) A4085, which is an α-olefin thermoplastic elastomer,
Using (product number) as a backbone polymer, MMA is graft-polymerized to this under the same conditions as the polymerization method described above (conditions for product B) to produce a copolymer of α-olefin thermoplastic elastomer and MMA. , an adhesive was prepared by dissolving it in a solvent consisting of ortho-xylene. Samples using such adhesive
Glue the backing material made of M1 and the PMMA resin plate,
As a result of the tensile test described above, an adhesive strength of 50 Kg/cm ² was obtained. This also has sufficient strength for practical use. Copolymers of polyolefin and MMA, specifically graft copolymers of polyethylene and MMA, graft copolymers of polypropylene and MMA, and graft copolymers of α-olefin thermoplastic elastomer and MMA are used as adhesive materials. The material was used in consideration of its compatibility with polyethylene or polypropylene contained in the olefinic thermoplastic elastomer.
Therefore, the above copolymer is not limited to a copolymer of polyethylene or polypropylene and MMA, but also a copolymer of polyethylene, polypropylene and MMA.
Alternatively, MMA may be further copolymerized with a copolymer of polyethylene or polypropylene and another substance such as vinyl acetate. (e) Durability of lining material and adhesive Figure 5 shows the durability test device, and 8 is a stainless steel base having a semi-cylindrical convex portion with a radius of 10 mm. 9 is a PMMA resin plate (made of GC Akron (registered trademark)) with a radius of 10 mm.
A lining material 3 made of sample M1 or M2 having a thickness of 1 mm is adhered to the recess with the above-mentioned adhesive (product B). Using a device with this structure, an alternating load of 3 Hz, 0 and 50 kg was applied in the direction of the arrow in the figure using a hydraulic servo dynamic property testing machine (manufactured by Saginomiya Seisakusho Co., Ltd.) in water at 37°C, and the degree of bond fatigue was observed. . The following table shows the results.

[Table] Through this experiment, it was confirmed that when the lining material and adhesive of this example were used, durability far superior to that of commercially available products could be obtained. (F) Method for manufacturing a denture base Figure 6 shows a method for manufacturing a denture base using the lining material and adhesive according to the present invention in the order of steps, and will be explained below with reference to the figures. (A) The jaw model 10 obtained from the patient is
It is formed of plaster 12 in a flask 11. A curable plastic material such as a dental slow polymerization resin, a photopolymerization resin material, or a thermosetting resin material is applied to the lining material forming area on the jaw model 10 (the entire surface of the complete denture shown in FIG. 1) to a predetermined thickness. For example, a thin layer 13 of about 1 mm is formed. Since this thin layer 13 corresponds to the part where the lining material will be formed later, it is treated, for example, by making the surface in contact with the thin part of the gingiva thicker. This thin layer 13 is shaped while it is in a plastic state and then hardened. (B) Wax 14 is raised in the shape of a denture base on the jaw model 10 including the thin layer 13, and the artificial teeth 4 are placed on this.
Array. Such work is usually performed by dentists. (C) A predetermined width of the peripheral portion of the denture base formed with wax 14 is removed. Since a lining material will eventually be formed in the cut portions 15, 15, the above-mentioned cutting process is performed while considering the portions that are preferably used as lining materials. (D) The cut portion 15 of the wax 14 is filled with unvulcanized plastic rubber 16, 16. The unvulcanized plastic rubbers 16, 16 are formed to be relatively thick in order to clearly define the boundary line with the denture base body, and are then vulcanized and hardened. Subsequently, plaster 41, 41 is poured around the vulcanized rubbers 16, 16 to fix the vulcanized rubbers 16, 16. Incidentally, in place of the vulcanized rubbers 16, 16, the above-mentioned curable plastic material can also be used. (E) After applying a separating agent to the surface of the plaster mold of the first flask 11, the second flask 17 is placed on top of this, and the plaster 18 in a fluid state is poured into it. (F) After the plaster 18 has solidified, the first and second flasks 11 and 17 are placed on top of each other,
It is placed in a container 19 and immersed in hot water at about 100°C for about 5 minutes. This causes the wax 14 to dissolve. (G) The pair of flasks 11 and 17 are divided and the wax 14 is removed by washing with hot water. (H) Thin layer 13 and vulcanized rubber 16 on the jaw model 10
is maintained in the first flask 1.
After applying a separating agent to the plaster surface of No. 1, a third flask 20 is superimposed on this, and this third
A flask 20 is filled with gypsum 21 in a fluid state. (I) After the plaster 21 has solidified, the first and third flasks 11, 20 are separated and the thin layer 13 and vulcanized rubber 16 are removed. This removal space 22 corresponds to the backing material forming space. This space is filled with the third material of the lining material in a heated and softened state. 23, 23 are burr grooves. Heating of the three lining materials can be done by immersing them in hot water, higher alcohol, cooking oil, etc.
Molding is possible at around 100℃. (J) Press the first and third flasks 11 and 20 and form the lining material 3. (K) After cooling the lining material 3, the first and third flasks 11 and 20 are divided to obtain the lining material 3 placed on the jaw model 10 of the first flask 11. An adhesive 24 is applied to the surface of this backing material 3. (L) After the adhesive 24 dries, the denture base forming space constituted by the first and second flasks 11 and 17 is filled with rice cake-shaped PMMA 25. (M) After that, the first and second flasks 11,
17 is compressed and placed in a container 26 at approximately 100℃.
or heated with hot water or steam at 130℃,
The denture base body 2 is formed by polymerizing and solidifying PMMA. At the same time, the lining material 3 is polymerized and bonded to the denture base main body 2. (N) After polymerization, first and second flasks 1
1 and 17 are divided and the plaster is destroyed, denture 27
is taken out. Thereafter, the thick portion of the lining material 3 is ground and formed, and the surface of the denture base main body 2 is polished to complete the denture 27. (G) Partial Dentures and Attachments The manufacturing method described above is also useful when applied to the production of partial dentures or dentures with attachments. 7A and 7B show a partial denture 28, in which the lining material 3 has protrusions 29, 29 at both ends, which are inclined toward the alveolar ridge mucosal surface of the adjacent natural teeth 30, 30. It maintains the denture by coming into contact with the undercut. 31 is the alveolar ridge. With such a structure, the protrusions 29, 29
Since it can move freely in the direction of the alveolar ridge mucosal surface, it does not adversely affect the denture's pressure-relaxing action by the lining material. FIG. 8 shows an example of the stud attachment 32, where 33 is a metal stud fixed to the tooth root 34, 3 is a lining material, and the attachment female 35 is a metal stud fixed to the tooth root 34.
It is formed at the same time when molding. 36 is a gingival part. Fig. 9 shows an example adopted in the Darbo attachment 37, and 38 is a metal mail.
It is fixed to the natural tooth 30. 3 is a backing material, and a female mail 39 that elastically holds the mail 38 is integrally molded with the backing material 3 at the same time. A metal ring 40 fixed to the artificial tooth 4 extends from the female mail 39, and the mail 38 engages with this metal ring 40. Reference numeral 29 designates two protrusions formed on the lining material 3 so as to abut the undercuts of the natural teeth 30 from the left and right sides of the attachment 37. The females 35 and 39 in these attachments allow the lining material 3 to perform a gentle pressure movement in the direction of the alveolar ridge mucosal surface of the denture. <Effects of the Invention> According to the present invention, the following effects can be obtained. As the lining material, an olefin-based thermoplastic elastomer or a mixed material of this olefin-based thermoplastic elastomer and a thermoplastic elastomer made of a styrene-ethylene-butylene copolymer is used, and as an adhesive, olefin and MMA are used.
By using the adhesive containing the copolymer, the lining material can be firmly bonded to the denture base body made of PMMA. Since the lining material softens over a range of temperatures above about 70°C, it can be molded by heating in hot water, steam, or edible oil. Therefore, a lining material of any shape can be easily produced without using a special machine. Since the hardness of the lining material can be set arbitrarily, it can be set to the optimum hardness suited to the case, and the problems of being too hard or too soft, which have conventionally been seen in commercially available products, are solved. In other words, lining materials having partially different hardnesses can be used depending on the operating characteristics in the oral cavity. At this time, the interface between materials of different hardness is completely integrated and continuous. Since a thermoplastic elastomer containing at least polyethylene or polypropylene is used as the lining material, the characteristics of polyethylene or polypropylene ensure appropriate leakage to saliva, resistance to contamination by oral bacteria, resistance to erosion, and resistance to staining with food coloring agents. It is possible to take advantage of its resistance to corrosion, etc., and improve its properties as a lining material. The lining material does not permanently change its rubber elasticity and is firmly adhered to the denture base body, so it can maintain a stable attachment function with strong suction force even after long-term use. Since the lining material can be formed into any shape, it can be used not only as a lining material for complete dentures, but also to integrally and simultaneously form the female attachments such as Dalboa attachments and stud attachments. It becomes possible. The above-mentioned female mail elastically supports and fixes the mail part using the rubber-like elasticity of the lining material, so there is no risk of its supporting function decreasing.On the contrary, it absorbs the impact applied to the denture, which reduces the burden placed on the alveolar ridge. can be reduced. Since the protrusion made of the lining material that contacts the natural tooth undercut does not prevent the denture from moving toward the alveolar ridge mucosal surface, the pressure-relaxing effect of the lining material on the denture is not hindered. The lining material is molded on the jaw model formed in the first flask, and then the denture base is polymerized and molded with this lining material placed on the jaw model, so the shape of the lining material, You can freely set the thickness etc.
Moreover, there is almost no possibility that an error will occur between the shape and the shape of the alveolar ridge attachment surface.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a denture base according to an embodiment of the present invention, and FIG. 2A is a hardness-temperature characteristic curve diagram when the mixing ratio of olefin thermoplastic elastomer and SEBS thermoplastic elastomer is changed.
Figure 2B shows the hardness-temperature characteristic curve when the mixing ratio is changed within the same type of olefinic thermoplastic elastomer, and Figure 3 shows the measurement results of the copolymer product using a differential thermal analyzer. Characteristic diagram, Figure 4 is a cross-sectional view of the sample for the adhesive strength measurement test, Figure 5 is a cross-sectional view of the equipment for the durability test,
6A to 6N are cross-sectional views showing the manufacturing method according to the embodiment of the present invention in order of steps, FIG. 7A is a top view showing one shape of a partial denture formed by the method of the embodiment, and FIG. B is a sectional view of FIG. 7A, No. 8
The figure is a sectional view showing another shape, and FIG. 9 is a sectional view showing still another shape. 1... Complete denture, 2... Denture base body, 3... Lining material, 4, 4... Artificial tooth.

Claims (1)

[Scope of Claims] 1. A denture base body made of polymethyl methacrylate resin, and a lining material having rubber elasticity adhered to the surface of the denture base body facing the alveolar ridge mucosal surface via an adhesive. In a denture base containing
The adhesive is made of a mixed material of thermoplastic elastomer made of ethylene-butylene copolymer.
Denture base 2 characterized in that it is made of a copolymer of olefin and methyl methacrylate.The olefin thermoplastic elastomer in the lining material contains at least polyethylene or polypropylene, and the adhesive is a copolymer of polyethylene or polypropylene and methyl methacrylate. The denture base 3 according to claim 1, characterized in that it is made of a polymer.The olefin-based thermoplastic elastomer in the lining material contains at least polyethylene or polypropylene, and the adhesive is an The denture base 4 according to claim 1, characterized in that it is made of a copolymer of a plastic elastomer and methyl methacrylate. Claims 1, 2, or 3 have a protrusion that abuts to maintain the denture and allows the lining material to exert gentle pressure in the direction of the alveolar ridge mucosal surface of the denture. Denture base 5 as described in Section 5. The lining material is integrally formed with a female of a stud attachment, and the female allows the lining material to perform a gentle pressure action in the direction of the alveolar ridge mucosal surface of the denture. The denture base 6 according to claim 1, 2, or 3, wherein the lining material is integrally formed with a female of a Dalboa attachment, and the female is a denture base made of the lining material. A denture base 7 according to claim 1, 2 or 3, which allows a gentle pressure action in the direction of the alveolar ridge mucosal surface.A method for manufacturing a denture base comprising the following steps.Olefin-based heat A step of heating and softening a mixed material of a plastic elastomer or an olefinic thermoplastic elastomer and a thermoplastic elastomer made of a styrene-ethylene-butylene copolymer to form a lining material in a predetermined shape, and placing the lining material on a jaw model. After applying an adhesive prepared by dissolving a copolymer of olefin and methyl methacrylate in a solvent and drying it, a rice cake-like polymethyl methacrylate obtained by kneading polymethyl methacrylate powder into liquid methyl methacrylate was pressed and heated. and polymerizing and solidifying the rice cake-like polymethyl methacrylate.