JP3862309B2 - Surface layer correction method for dental mineral models - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for correcting a surface layer of a dental plaster model (model) (improvement of strength and hardness, improvement of compatibility with a separating agent, etc.).
[0002]
[Prior art]
Gypsum is widely used in dental models for reproducing the patient's mouth. That is, first, an impression is given from the patient's oral cavity, and a model is prepared by injecting gypsum into it, and a prosthesis is prepared based on the model. In this case (especially when a processed denture is made), the gypsum model may be insufficient in strength and hardness, or may be chipped. Therefore, it is necessary to take measures to eliminate such trouble.
[0003]
As a means of improving the strength and hardness of the gypsum model, a method of kneading a reinforcing agent as a gypsum hardener to the composition for preparing the gypsum model (kneading type), and a reinforcing agent after preparing the gypsum model There is a method (coating penetration type) in which the surface layer is reinforced by coating and penetration. When both types are compared, the latter coating penetration type seems to have a more preferable effect of improving surface strength and hardness.
[0004]
Among the methods for improving the strength and hardness of gypsum models, the latter coating penetration type reinforcing agents are: (a) natural evaporation type (a solution in which an acrylic polymer or other polymer is dissolved in a solvent; (B) a solvent that evaporates after application to exhibit a binder action or film formation action), (b) a crosslinked type (a solution in which a reactive resin such as an epoxy resin is diluted in a solvent) (C) Instant adhesive type (diluted solution in which instant adhesive mainly composed of 2-cyanoacrylate is diluted with solvent), the main agent is a gypsum model There is one that utilizes the phenomenon of rapid curing by reacting with moisture in the pores, and all are commercially available. Note that (c) is the method disclosed in Japanese Patent Laid-Open No. 2-69371 relating to the application of one of the applicants.
[0005]
[Problems to be solved by the invention]
The coating penetration type strengthening agent that strengthens the surface layer by applying and infiltrating the gypsum model is (1) improved strength and hardness, especially improved strength, (2) fastened, and (3) applied to the surface. The film to be formed should be as thin as possible, and if possible, no film should be formed on the surface. (4) When a film is formed on the surface, the film should not be peeled off during the hot water washing process, etc. It is easy to separate from the wax, resin, porcelain, etc. built on it when applying force, (6) It is not limited to exhibiting one physical property, and the curing state can be changed Therefore, it is desirable to satisfy the required properties such as the property of the permeated surface layer being freely changeable.
[0006]
The reinforcing agent (a) described above is used by allowing a solution obtained by dissolving an acrylic polymer or other polymer in a solvent to be applied and permeated into a model, and allowing the solvent to spontaneously evaporate. However, this method increases the viscosity due to the absorption of the solvent through the pores of the model and the volatilization of the solvent from the surface, so that the solution does not necessarily penetrate sufficiently to the inside, and it is avoided that a film is formed on the surface. Absent. If the film remains on the surface as described above, the dimensional accuracy is adversely affected, and the film may be peeled off in a subsequent hot water washing process, which adversely affects the final product. Further, due to the solvent remaining in the polymer, there is a problem that sufficient strength cannot be obtained immediately after the treatment.
[0007]
The toughening agent (b) above is a model in which a solution obtained by diluting a reactive resin such as an epoxy resin in a solvent is applied and penetrated into the model. Since it takes a very long time to reach curing (usually it takes half a day or one day), there is a problem that it is not easy to use at the site of a dental technician.
[0008]
The method of applying and penetrating a diluted solution obtained by diluting the instant adhesive mainly composed of 2-cyanoacrylate of (c) with a solvent, has a significantly faster curing speed and higher hardness than the above (a) and (b). Although it is preferable in terms of the obtained point, the 2-cyanoacrylate in the contacted solution is cured on the surface before penetrating into the inside to form a thick film, and in order to avoid this, compression is performed before the curing starts. Although excessive air is blown off by blowing air, there are disadvantages such as complicated operation and concern about odor.
[0009]
And all the reinforcing agents (a), (b) and (c) above can obtain only one physical property with one material, and change the cured state according to the case and change the properties of the permeated surface layer. There was a restriction that it could not be changed freely.
[0010]
Under such a background, the present invention can be quickly cured when necessary, and since it is fast curable, the curing time is short, and the degree of polymerization can be freely controlled from intermediate polymerization to complete polymerization. Regardless of the type of separating agent or build-up material, it is possible to improve the familiarity with them, and the strength and hardness of the model surface layer can be improved without giving thickness, so the dimensional accuracy of the model is impaired It is an object of the present invention to provide a method for correcting the surface layer of a dental inorganic model that does not cause a problem of film peeling in a hot water washing process or the like.
[0011]
[Means for Solving the Problems]
The method for correcting the surface layer of the dental inorganic model of the present invention is such that the photopolymerizable monomer (i) and polyester acrylate, polyester urethane acrylate, epoxy acrylate, polyol acrylate are formed on the fine irregularities or voids of the surface layer of the dental inorganic model. And a photocurable resin liquid having a viscosity of 10 cps or less containing a photocurable resin composed of a photopolymerizable prepolymer (ii) selected from the group consisting of silicone acrylate as a main ingredient and containing a solvent and a silicone surfactant. After completely infiltrating so as not to cause surface residue , light irradiation is performed to cure the permeated photocurable resin.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail below.
[0013]
Dental inorganic model, plaster, refractory or metallic dental model and the like.
[0014]
In the present invention, a low-viscosity photocurable resin liquid is infiltrated into fine irregularities or voids on the surface layer of the dental inorganic model, and then light irradiation is performed to cure the permeated photocurable resin.
[0015]
As the photocurable resin liquid, a liquid mainly composed of a photocurable resin composed of a photopolymerizable monomer (i) and a photopolymerizable prepolymer (ii) is used. Here, as the former photopolymerizable monomer (i) , monofunctional acrylate, bifunctional acrylate, trifunctional or higher acrylate, etc. are used, and as the latter photopolymerizable prepolymer (ii) , polyester acrylate is used. , Polyester urethane acrylate, epoxy acrylate, polyol acrylate, and silicone acrylate are used. In addition, various modifying components can be added to the main agent as necessary . Here, acrylate is a concept including methacrylate. For the purpose of the present invention, since it is sufficient that the hardness reaches a predetermined level, a composition such as including a soft segment is considered in consideration of an improvement in strength (friction strength, impact resistance, bending strength, etc.). Care should be taken to make the above efforts.
[0016]
Since the photocurable resin liquid needs to have a low viscosity, the mixing ratio of each component is determined in consideration of the ratio of the photopolymerizable monomer (i) and the photopolymerizable prepolymer (ii) . The viscosity of the photocurable resin liquid at this time is desirably as low as possible at room temperature, such as 200 cps or less, 100 cps or less, or 50 cps or less.
[0017]
In the present invention, in order to further reduce the viscosity of the photocurable resin liquid, an appropriate amount of solvent (for example, 0.01 to 50 parts by weight, preferably 0.05 to 30 parts by weight, more preferably 1 part by weight of the resin content) 0.1 to 20 parts by weight) . Examples of the solvent include alcohol-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, hydrocarbon-based solvents, halogen-containing solvents, nitrogen-containing solvents, water, and the like, and may be mixed solvents thereof. . The viscosity of the photocurable resin liquid after blending the solvent is set to 10 cps or less at room temperature, and can be brought to a viscosity close to water (1 cps) (for example, 1.5 cps).
[0018]
In order to perform the photocuring reaction smoothly, it is usual to add about 0.01 to 5% by weight of a photoinitiator (including a sensitizer) to the photocurable resin liquid. As the photoinitiator, those sensitive to light having a wavelength of 200 to 600 nm are used. In this case, it is preferable to use a photoinitiator that is sensitive to visible light wavelengths of 380 to 600 nm, particularly 400 to 600 nm, so as not to harm the operator. Note that the wavelength range of visible light is about 400 to 800 nm, and the wavelength range of ultraviolet light is about 100 nm in a smaller range.
[0019]
Furthermore, in this invention, in order to improve the permeability with respect to a dental inorganic model , the silicone type surfactant which is a surfactant with a large surface tension reduction ability is mix | blended with a photocurable resin liquid . The amount of the silicone-based surfactant is often about 0.0001 to 10% by weight, particularly 0.001 to 5% by weight, based on the resin content (residue excluding the solvent component). The amount is not necessarily limited to this range.
[0020]
In addition, additives such as a colorant, a stabilizer, an antibacterial agent, a plasticizer, and various modifiers can be added to the photocurable resin liquid as necessary.
[0021]
As a light source for performing light irradiation, a metal halide lamp, a high-pressure mercury lamp, a low-pressure mercury lamp, a xenon lamp, a fluorescent lamp, or the like is used, and sunlight may be used. According to light irradiation, the degree of polymerization can be freely controlled from intermediate polymerization to complete polymerization, whereby the best correction according to the purpose can be performed.
[0022]
For the penetration of the above-mentioned photocurable resin liquid into the dental inorganic model, the resin liquid is applied to the model using a brush, brush, etc., the resin liquid is dropped from the nozzle onto the model, and the resin liquid is sprayed onto the model. A method, a method of dipping a model into a resin liquid, or the like is employed. From the viewpoint of uniform application and operability, the spray method is particularly preferable. After impregnated with photocurable resin solution in the dental inorganic model may be impregnated again additionally said photocurable resin liquid.
[0023]
When the photocurable resin liquid is infiltrated into the fine irregularities or voids on the surface layer of the dental inorganic model according to these methods, if the viscosity, composition, contact time, surfactant content, etc. are considered, The hardened material film can be substantially absent on the surface of the dental mineral model . Whether or not a polymer film is stretched on the surface can be measured using a surface roughness meter, but since the film becomes glossy when it is stretched, it can be easily confirmed with the naked eye by the presence or absence of gloss. it can.
[0024]
<Action>
The photopolymerizable monomer (i) and the photopolymerizable prepolymer (ii) used in the photocurable resin liquid have a low viscosity and are 100% reactive per se, so that an osmotic curing agent having good permeability even if it is used as it is. on preparation of it is easy, in the present invention since the addition of even large silicone surfactant and and a surface tension reducing ability in a combination of solvents, which is intended to improve further penetration.
[0025]
The low-viscosity ( less than 10 cps ) photo-curing resin liquid prepared in this way has no gelation or thickening until it is irradiated with light, and has good permeability, so fine irregularities on the surface layer of the dental mineral model Alternatively, it sufficiently penetrates into the gap and fills the gap. And if it irradiates with light in such a state, it hardens at a speed of seconds or minutes and the surface layer portion of the model becomes a cured product of a predetermined hardness, and exhibits the effect as a reinforcing agent immediately after curing. In addition, it is possible to prevent a film from being substantially formed on the surface. Even after the permeation treatment is performed, it does not cure unless it is irradiated with light. Therefore, there is an advantage that the timing for performing the curing can be arbitrarily set. In addition, smooth curing in the wavelength range of visible light that does not harm the worker is also possible.
[0026]
In general, when a separating agent is applied to a model after processing and a wax, resin, porcelain or the like is built thereon, the separating agent may not be uniformly applied. However, in the present invention, the amount of polymerization can be controlled in accordance with the type of separating agent, and the degree of polymerization can be limited to intermediate polymerization that does not reach from that to complete polymerization. The degree of compatibility with the separating agent can be greatly improved, and as a result, the wax, resin, porcelain, etc. built on it will not peel off after curing, and it will be as good as fingers. It becomes possible to enable easy separation with a light force.
[0027]
Thus, according to the present invention, favorable permeability to the dental mineral model is ensured, the strength and hardness of the model surface layer can be improved without imparting thickness, and the familiarity with the separating agent is improved. Can do.
[0028]
【Example】
The following examples further illustrate the invention. Hereinafter, “parts” means parts by weight. In any of the examples, a visible light sensitive type photoinitiator is used.
[0029]
<Examples 1 to 4 >
Example 1 (Reference Example)
Hexamethylene diisocyanate trifunctional urethane acrylate 40 parts, 1,6-hexanediol diacrylate 30 parts, methyl methacrylate 30 parts, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropanone-1 4 And 0.4 parts of diethylthioxanthone were charged into a beaker and mixed and dissolved while heating to 60 to 70 ° C. As a result, a photocurable resin liquid having a viscosity of 100 cps or less was obtained.
[0030]
When the photocurable resin solution prepared above was applied to a cristobalite investment used in a dental model with a brush, it completely penetrated after 2 minutes and was apparently dry.
[0031]
In this state, light irradiation was performed with a 150 W halogen lamp (400 to 500 nm) at an irradiation distance of 5 cm for 30 seconds. When the model subjected to such treatment was cut and observed, it was found that the model penetrated from the surface layer to a depth of about 1 mm and solidified.
[0032]
Example 2
To the resin solution used in Example 1, 0.1 part of a silicone-based surfactant (“BYK-306” manufactured by Big Chemie Co., Ltd.) having a large surface tension reducing ability was added and further diluted with toluene to 50%. The viscosity was 10 cps or less. When this solution was applied to superhard plaster and anhydrite used in a dental model with a brush or by spraying, the solution completely penetrated after 30 seconds to 1 minute and was apparently dry. Virtually no coating was observed on the model surface.
[0033]
After curing under the same lamp and irradiation conditions as in Example 1, the model was cut and observed, and it was found that it penetrated from the surface layer to a depth of 1 to 2 mm and solidified.
[0034]
Example 3
10 parts of pentaerythritol triacrylate, 15 parts of urethane acrylate oligomer, 25 parts of isobornyl acrylate, 0.05 part of BYK-306 ( silicone surfactant) described above, 2-benzyl-2-dimethylamino-1- (4-morphol After charging 2 parts of linophenyl) -butane-1 into a beaker and heating and dissolving at 80 to 90 ° C., 50 parts of isopropanol was added. As a result, a low viscosity photocurable resin solution of 10 cps or less was obtained.
[0035]
The four types of models used in dental models (Cristobalite investment, phosphate investment, cemented gypsum, anhydrite) are sprayed or sprayed with the photocurable resin solution prepared above. As a result, all of them permeated completely in 30 seconds or less and apparently dried. Virtually no coating was observed on the model surface.
[0036]
After curing under the same lamp and irradiation conditions as in Example 1, the model was cut and observed, and it was found that all four types penetrated from the surface layer to a depth of about 2 mm and were solidified.
[0037]
Example 4
10 parts of pentaerythritol tetraacrylate, 10 parts of polyester urethane acrylate oligomer, 30 parts of hydroxypropyl methacrylate, 0.1 part of BYK-306 ( silicone surfactant), 0.5 part of diethylthioxanthone, 1 part of p-dimethylaminobenzoic acid ethyl ester After charging into a beaker and heating and mixing at 60 to 70 ° C., 50 parts of isopropanol was added. As a result, a low viscosity photocurable resin solution of 10 cps or less was obtained.
[0038]
As in Example 3, the photocurable resin liquid prepared above was applied to four models (Cristobalite investment material, phosphate investment material, cemented gypsum, and anhydrite) using a brush or by spraying. As a result, all penetrated completely in 30 seconds or less, and seemed to be in a dry state.
[0039]
After curing under the same lamp and irradiation conditions as in Example 1, the model was cut and observed, and it was found that all four types penetrated from the surface layer to a depth of about 2 mm and were solidified.
[0040]
<Comparison test on the degree of surface roughness (film formation)>
Three types of reinforcing agents A, B, and C of a commercially available coating type resin type, the photocurable resin liquid N of Example 3 above, and a commercially available cyanoacrylate-based reinforcing agent D were used, and a gypsum model was used. Apply a small brush at a few centimeter intervals (applied twice), irradiate with a 1KW metal halide lamp at an irradiation distance of 12.5cm for 15 seconds, and let stand for another day. Used to measure the surface roughness continuously. The chart at this time is shown in FIG. The reason why the baseline is curved in FIG. 1 is that the contour of the model itself is curved.
[0041]
From FIG. 1, when the reinforcing agents A, B, C, and D are used, the surface roughness is more or less, but when the photocurable resin liquid N of Example 3 is used, the surface is not applied. It can be seen that the film has no smoothness (that is, virtually no film is formed on the surface). Even when the light is observed from an oblique direction, no gloss is produced in the case of N. From this, it is qualitatively understood that no film is formed in the case of N.
[0042]
<Comparative test on peelability of formed film>
For the dental gypsum model, the same commercially available coating penetration type resin type three reinforcing agents A, B, C, the photocurable resin liquid N of Example 4 above, a commercially available cyanoacrylate type reinforcing agent After 5 types of D were applied and infiltrated, irradiation was performed with a 1 KW metal halide lamp at an irradiation distance of 12.5 cm for 15 seconds, and the mixture was left for 1 day, and then washed with hot water and water. The coating and penetration of N produced virtually no coating, so the problem of coating peeling did not occur. However, the coating and penetration of A, B, C and D partially peeled off the coating during hot water washing. occured.
[0043]
<Comparison test on familiarity with separating agent>
In each of the dental gypsum models, three types of reinforcing agents A, B, C of the same commercially available coating-penetrating resin type as above, the photocurable resin liquid N of Example 2 above, a commercially available cyanoacrylate-based resin After 5 types of reinforcing agents D were applied and infiltrated, N was irradiated with ultraviolet rays for intermediate polymerization, and A, B, C and D were left as they were for 1 day. Then, a commercially available wax separating agent was applied to these, and a softened wax was built up by heating. N-coated and permeated had good compatibility with the wax separating agent, and therefore did not peel off after curing, and the wax built up on it could be easily separated with a light force of finger level. On the other hand, when A, B, C, and D were applied and penetrated, familiarity with the wax separating agent itself was not always sufficient.
[0044]
【The invention's effect】
According to the present invention, it can be quickly cured when necessary, and since it is fast-curing, the curing time is short, and the degree of polymerization can be freely controlled from intermediate polymerization to complete polymerization. It is possible to improve the familiarity with them regardless of the type of material, and it is possible to improve the strength and hardness of the model surface layer without giving thickness, so that the dimensional accuracy of the dental mineral model is not impaired Excellent effects such as no problem of film peeling in the hot water washing process and the like are exhibited.
[Brief description of the drawings]
FIG. 1 is a chart showing the results of a comparative test on the degree of surface roughness when applied to a gypsum model.

Claims (2)

A photopolymerizable pre-polymer selected from the group consisting of photopolymerizable monomer (i) and polyester acrylate, polyester urethane acrylate, epoxy acrylate, polyol acrylate and silicone acrylate is formed on the fine irregularities or voids on the surface of the dental inorganic model. After completely infiltrating a photocurable resin liquid having a viscosity of 10 cps or less containing a photocurable resin composed of the polymer (ii) as a main component and containing a solvent and a silicone-based surfactant so as not to cause surface residue , A method for correcting a surface layer of a dental inorganic model, wherein light penetration is performed to cure a permeated photocurable resin. Inorganic model for dentistry, the correction method of claim 1, wherein plaster, a refractory or metallic dental model.

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