JPH0319781B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD OF THE INVENTION The present invention relates to a method for producing a denture base having an excellently smooth lining surface. More specifically, the general formula:

[Formula] (R ¹ is a hydrogen atom or a methyl group, R ² is a fluorine-containing telomer with a molecular weight of 200 to 1500.) 100 parts by weight of monomer, 3 to 30 parts by weight of fluorine-containing copolymer part and polymerization initiator 0.1-3.0
A method for manufacturing a denture base having an excellent smooth lining surface, which comprises lining and molding a lining material consisting of a weight part of acrylic resin denture base material whose polymerization starts after the exothermic peak of polymerization of the lining material. Regarding. Conventional technology An acrylic resin denture base material and a backing that has a cushioning effect that eliminates various obstacles caused by pressure on the mucosal surface by the hard denture base material, supplements the elasticity of the maxillary mucosa, and cushions the impact during occlusion. A number of denture bases consisting of denture materials have been proposed in the past. As a soft lining material that acts as a shock absorber, it relieves the occlusal pressure applied to the mucosal surface, alleviates the pain that occurs during occlusion, improves the compatibility and suction of the floor to the jawbone, and alleviates local bone resorption. , acrylic-based soft lining materials, silicone-based lining materials, and fluorine-based lining materials have been proposed. In particular, as a fluorine-based backing material, a backing material made of a fluorinated carbon resin selected from fluorinated polyolefin and fluorinated polyvinylidene (US Pat. No. 3,889,374); Lining material consisting of vinylidene fluoride units, 20 to 30 parts by weight of tetrafluoroethylene units, and 20 to 30 parts by weight of hexafluoropropylene units and/or chlorotrifluoroethylene units (US Pat. No. 4,484,894); Lining material of a fluorine-containing monomer having one double bond in the molecule, which is obtained by esterifying a fluorine-containing multicomponent telomer having one OH group at the chain end and acrylic acid chloride or methacrylic acid chloride. (Japanese Patent Application Laid-open No. 59-117503); General formula:

[Formula] 100 parts by weight of a monomer represented by (R ¹ is H or CH ₃ , R ² is an oligomer with a molecular weight of 1500 or less) and an alkyl ester of acrylic acid or methacrylic acid (the alkyl group has 1 to 5 carbon atoms) A copolymer lining material consisting of 3 to 30 parts by weight (Japanese Unexamined Patent Application Publication No. 112707/1983) and the general formula:

[Formula] (R ¹ is H or CH ₃ , R ² is a fluorine-containing telomer with a molecular weight of 200 to 1500) 100 parts by weight of a monomer, 3 to 30 parts by weight of a fluorine-containing copolymer, acrylic acid or A lining material (US Pat. No. 4,579,881) has been proposed that is a mixture of 3 to 30 parts by weight of an alkyl ester of methacrylic acid (the alkyl group has 1 to 12 carbon atoms) and 0.1 to 3.0 parts by weight of a polymerization initiator. The lining material disclosed in US Pat. No. 4,579,881 is
Because it is extremely soft, it has good operability by technicians, and can be lined without any special operations when preparing denture bases by conventional methods.The hardness of the polymerized lining surface is 10 to 30 Shore type A, 25°C), and has elasticity, so it has the effect of relieving occlusal pressure and transmitting it to the oral mucosal surface, and has excellent compatibility and adsorption properties between dentures and jaw ridges, and is highly elastic. Apply 2
It is durable with no deterioration even after more than a year, and has shown excellent effects in alleviating patient pain. However, denture bases using this lining material are
Depending on the type of acrylic resin denture base material used, unevenness may occur on the surface of the lining that comes into contact with the rim. That is, there are several dozen types of acrylic resin denture base materials that are currently in use, which are a mixture of methyl methacrylate and polymethyl methacrylate, and these acrylic resin denture base materials have the above-mentioned lining. If a denture base is made by lining the material and polymerizing it using a heating polymerization method, depending on the type of acrylic resin denture base material, it may not be possible to obtain a smooth lining surface.
The backing surface may be uneven. As a result of investigating the cause of the uneven lining surface, the present inventors found that the polymerization rate differs depending on the type of acrylic resin denture base material. It has been found that if the polymerization rate of the acrylic resin denture base material is slower than the polymerization rate of the lining material, the lining surface becomes uneven, and if the polymerization rate of the acrylic resin denture base material is slower than the polymerization rate of the lining material, a smooth lining surface is formed. Based on this knowledge, we have accomplished the present invention. Structure of the Invention The lining material used in the present invention has the general formula: (R ¹ is a hydrogen atom or a methyl group, R ² has a molecular weight of 200
~1500 fluorine-containing telomers. ), 3 to 30 parts by weight of a fluorine-containing copolymer, and 0.1 to 3.0 parts by weight of a polymerization initiator. When the lining material of this putty-like mixture is heated to about 75°C, polymerization starts after about 14 minutes, and an exothermic peak appears after about 18 minutes. When this lining material is lined with an acrylic resin denture base material that starts polymerizing after about 12 minutes at a polymerization temperature of 75°C and molded (heated and polymerized at about 75°C), a putty-like lining forms after about 12 minutes. The material becomes softer and more fluid. Under these conditions, the acrylic resin denture base material rapidly polymerizes, and the generated polymerization heat (heat peak at 14.5 minutes) causes the acrylic resin denture base to expand instantaneously. Due to this expansion, the soft and easily flowable lining material flows out from between the interlocking upper and lower flasks, resulting in a shortage of lining material in the flask. Polymerization of the lining material occurs when there is insufficient lining material in the flask, so the lining surface of the resulting denture base becomes uneven. On the other hand, when using an acrylic resin denture base material that starts polymerizing after about 20 minutes at a polymerization temperature of 75°C and lining it with the lining material of the putty-like mixture described above and molding it, After about 18 minutes, the lining material polymerizes and solidifies into a predetermined shape. After about 20 minutes, the acrylic resin denture base material starts to polymerize, followed by rapid exothermic expansion (exothermic peak: 23
Even if this happens after several minutes, the lining material no longer flows out from between the interlocked upper and lower flasks, making it possible to obtain a denture base with an extremely smooth lining surface. Therefore, in order to obtain a denture base with an extremely smooth lining surface, the acrylic resin denture base material must have a polymerization start time that is later than the exothermic peak of polymerization of the lining material used in the present invention. It is necessary to use an acrylic resin denture base material. For example, the polymerization exothermic peak at a temperature of 75℃ is
If the lining material is used for 18 minutes or less, it must be lined with an acrylic resin denture base material whose polymerization start time at 75°C is 18 minutes or later, and if the polymerization start time is 20 minutes or later, the exothermic peak of polymerization will occur at 23 minutes. It is preferable to line it with the following acrylic resin denture base material. Of course, it is preferable if the polymerization start time of the acrylic resin denture base material is 20 minutes or later and the polymerization exothermic peak is 23 minutes or later, but due to the workability of denture base manufacturing, it is preferable that the polymerization start time is 22 to 30 minutes. Acrylic resin denture base materials having an exothermic peak in the range of 25 to 40 minutes are more preferred. Examples of currently commercially available acrylic resin denture base materials include: Akron and Kuitsu Akron (Jishi Toto Kogyo Co., Ltd.)
natural resin and α-resin (manufactured by Nitsushin Co., Ltd.), bioresin (manufactured by Shofu Co., Ltd.), heat shot resin and L-resin (manufactured by Sankin Kogyo Co., Ltd.), Apollon (manufactured by Yamahachi Dental Co., Ltd.) ), Newdevron (manufactured by Toyo Kagaku Kenkyusho Co., Ltd.), Luciton 199 (manufactured by Caulk), Meliodent (manufactured by Bayer Nippon Dental Co., Ltd.), and QC-20 (manufactured by DE TREY). Among these commercially available acrylic resin denture base materials, denture base materials with a polymerization start time of less than 20 minutes are made by adding a polymerization inhibitor to control the polymerization rate, so that the polymerization start time is 20 minutes or more, and the polymerization start time is less than 20 minutes. It is necessary to adjust the exothermic peak to 23 minutes or later before use. The amount of the polymerization inhibitor added is preferably 0.003 to 0.02 parts by weight based on 100 parts by weight of the acrylic resin denture base material. The polymerization inhibitor is not particularly limited as long as it delays the initiation of polymerization, but benzoquinone,
Examples include hydroquinone, pt-butylcatechol, and pyrogallol. The lining material made of the putty-like mixture of the present invention can be produced by the method described in JP-A-59-117503 and JP-A-60-146810. For example, by telomerizing a fluorine-containing monomer in an alcohol such as methanol or ethanol, a fluorine-containing telomer having an OH group at the end of the molecular chain can be obtained. The monomer represented by the formula () can be easily obtained by dissolving it in a solvent such as carbon chloride and carrying out an esterification reaction with acrylic acid chloride or methacrylic acid chloride. The fluorine-containing monomers used include vinylidene fluoride, vinyl fluoride, trifluoroethylene,
It is preferable to use at least two types of monomers selected from chlorotrifluoroethylene, tetrafluoroethylene, and hexafluoropropylene, and as the fluorine-containing telomer constituting the ester moiety of the monomer represented by formula (), , the binary or ternary molecular weight of the above-mentioned fluorinated olefin monomer is from 200 to
A telomer of 1500 is preferred. Since the ester component of the monomer represented by the formula (), which is the main raw material of the putty-like mixture, is composed of a multi-element fluorine-based telomer, the polymerized and solidified backing material layer has appropriate flexibility and excellent durability. The fluorine-containing copolymer, which is one of the other raw materials for the lining material of the putty-like mixture, is selected from vinylidene fluoride, vinyl fluoride, trifluoroethylene, chlorotrifluoroethylene, tetrafluoroethylene, and hexafluoropropylene. A copolymer consisting of at least two types of fluorinated olefin monomers, the amount of which is 10 to
It has a rigidity of 150Kg/cm ² . Examples of the polymerization initiator include organic peroxides having a long half-life at room temperature, such as benzoyl peroxide and ditertiary butyl peroxide. The method for producing the lining material of the putty-like mixture is to use 100% of the monomer represented by the formula ()
3 to 30 parts by weight of fluorine-containing copolymer powder are added to the parts by weight and kneaded. Kneading may be carried out at room temperature or under heating, and it is particularly preferable to carry out heating at 120 to 150°C since this allows for better kneading. Cool the kneaded product to room temperature, add 0.1 to 3.0 parts by weight of a polymerization initiator, or add 3 to 30 parts by weight of an alkyl (meth)acrylate in which 0.1 to 3.0 parts by weight of a polymerization initiator has been dissolved, and stir at room temperature. By thoroughly kneading the mixture until it becomes uniform again, a lining material of the putty-like mixture can be obtained. The resulting backing material of the putty-like mixture has appropriate softness, has an intrusion resistance value of 5 to 50 g/mm ² , and has excellent technical operability. The lining material of the putty-like mixture obtained is placed on the lining surface of the acrylic resin denture base material molded with plaster in a flask, and the lining material is prepared by heating and pressurizing and crimping according to a conventional method. It is possible to obtain a denture base lined with The denture base of the present invention has a hardness of 10 to 30 (Shore type A,
25℃), it is lined with a viscoelastic lining material that acts like a shock absorber, so it has excellent lubricity and relieves occlusal pressure, transmitting it to the oral mucosal surface. It has excellent compatibility and adsorption properties between dentures and jaw ridges, excellent chemical stability in the oral cavity, and has amazing durability without any deterioration even after two years or more. The present invention will be specifically explained below with reference to Examples, but it is not limited to these Examples as long as it falls within the scope of the claims of the present application. Example 1 Manufacture of backing material General formula:

In [Formula], 100 g of a fluorine-containing methacrylic acid ester in which R ² is a telomer with a molecular weight of 1150 consisting of 50 parts by weight of vinylidene fluoride, 30 parts by weight of chlorotrifluoroethyne, and 20 parts by weight of tetrafluoroethylene are combined separately. Polymerized vinylidene fluoride/chlorotrifluoroethylene/tetrafluoroethylene = 50/30/20 (weight ratio)
Soft fluorine copolymer (rigidity: 67Kg/cm ² )15
g, 12 g of fine powder silica (AEROSIL R-972) and 2 g of benzoyl peroxide were poured into a mortar and kneaded at room temperature (26°C) to form a putty-like mixture lining material [penetration resistance value (hardness): 7.6 g/mm]. It was ² . ] was obtained. The polymerization initiation time of the resulting putty-like mixture lining material at 75°C was 14 minutes, and the exothermic peak time was
It took 18 minutes [Crepeto Dough: Kureha Chemical Industry]
Soft lining material made by Co., Ltd.]. [Measurement method of penetration resistance value]: 9g of the sample was placed in a compression cell using a Tensilon tester, and after adjusting the temperature to 20℃, a stainless steel rod with a diameter of 2.3m/m was penetrated into the sample at a speed of 100mm/min. The resistance value at that time is shown in g/mm ² . Production of denture base As an acrylic resin denture base material, commercially available α-resin [manufactured by Nitsushin Co., Ltd.] has a polymerization start time of 27.5 minutes at 75°C and an exothermic peak time of 31.5 minutes.
It's a minute. ] is inserted into a plaster mold in a denture making flask that has been pre-shaped by a conventional method, and then a 1.2 mm thick piece of paraffin wax is pressed against the backing surface of the filled denture base material. Secured the volume for lining the material. The backing material of the putty-like mixture obtained above was filled into the space secured with paraffin wax. After the upper and lower flasks were pressed together, they were heated in a constant temperature water bath at 70°C for 40 minutes, and then heated and polymerized in boiling water for 40 minutes. After polymerization, when the flask was opened after being cooled to room temperature, a denture base with an extremely smooth lining surface (Fig. 2, photo) and a Shore hardness (Type A) of 23 was obtained.
When the denture base obtained in this example was applied to the oral cavity of a 70-year-old woman, no deterioration was observed even after 2 years, and continued use was possible. [Measurement of polymerization rate]: 10 g of a putty-like sample was rolled into a dumpling, the tip of a temperature sensor was inserted into the center, the entire dumpling was wrapped in polyethylene film, and immersed in a constant temperature water bath at 75°C ± 0.2°C. The relationship between time and temperature was recorded, and the starting time of polymerization and the exothermic peak time were measured. Examples 2 to 4 and Comparative Example 1 As an acrylic resin denture base material, a commercially available natural resin [manufactured by Nitsushin Co., Ltd., polymerization start time at 75°C is 12 minutes, exothermic peak time
It is 14.5 minutes. ] 0.0014g of hydroquinone in 20g
(Example 2), 0.0020g (Example 3), and 0.0040
g (Example 4) were respectively added and kneaded to obtain samples. A natural resin to which no hydroquinone was added was prepared for comparison (Comparative Example 1). The results of measuring the polymerization initiation time and exothermic peak at 75°C for each sample are shown in Figure 1 and Table 1. A denture base was obtained in the same manner as in Example 1 using the sample thus obtained. The denture bases of Examples 2 to 4 each had an extremely smooth lining surface as shown in FIG. 2 of Example 1, and had a Shore hardness (type A).
was 23. When the denture base obtained in Example 2 was applied to the oral cavity of a 65-year-old man, no deterioration was observed even after 2 years, and continued use was possible. The lining surface of the denture base obtained in Comparative Example 1 was uneven (Fig. 3, photograph). Examples 5 to 10 Denture bases were manufactured in the same manner as in Example 1 using commercially available acrylic resin denture base materials shown in Table 1 as acrylic resin denture base materials. The resulting denture bases each had an extremely smooth lining surface as shown in FIG. 2, and the Shore hardness (type A) was 23. Examples 11 to 14 and Comparative Examples 2 to 5 Using commercially available acrylic resin denture base materials shown in Table 1 as acrylic resin denture base materials, 0.0024 g of hydroquinone was added to 20 g of the acrylic resin denture base materials (Example 11) ), 0.0014g (Example 12),
0.0010g (Example 13) and 0.0010g (Example 14)
A denture base was manufactured in the same manner as in Example 2. The obtained denture bases each had an extremely smooth lining surface as shown in FIG. 2, and the Shore hardness (type A) was 23. On the other hand, commercially available acrylic resin denture base materials shown in Table 1 without the addition of hydroquinone were prepared for comparison (Comparative Examples 2 to 5), and denture bases were manufactured in the same manner as in Example 2. The lining surface of the obtained denture base was
It was uneven as shown in the picture.

【table】 [Brief explanation of the drawing]

FIG. 1 is a diagram showing the relationship between polymerization time and polymerization temperature of the natural resins of Examples 2 to 4 and Comparative Example 1 and the mixture of natural resins with hydroquinone added. 1 is a photograph of the lining surfaces of denture bases manufactured in Example 1 and Comparative Example 1.

Claims (1)

[Claims] 1 General formula: 100 parts by weight of a monomer represented by the formula (R ¹ is a hydrogen atom or a methyl group, R ² is a fluorine-containing telomer with a molecular weight of 200 to 1500), A lining material consisting of 3 to 30 parts by weight of a fluorine-containing copolymer and 0.1 to 3.0 parts by weight of a polymerization initiator is lined with an acrylic resin denture base material whose polymerization starts after the exothermic peak of polymerization of the lining material and molded. A method for manufacturing a denture base, characterized by: 2. The acrylic resin denture base material contains 100 parts by weight of the acrylic resin denture base composition and 0.003 to 0.02 parts by weight of a polymerization inhibitor.
The method for manufacturing a denture base according to claim 1, characterized in that the method comprises: parts by weight.