JP4689476B2 - Curable composition - Google Patents

Description

The present invention relates to a dental curable composition, and more particularly to a dental curable composition for producing a cured resin body having a small polymerization shrinkage.

  In various applications such as printing plate making, photoresist materials, paints, adhesives, inks and model materials, curable compositions comprising radical polymerizable monomers and polymerization initiators are widely used. Among these, in the dental field, those using (meth) acrylate polymerizable monomers as radical polymerizable monomers include dental cement, dental adhesive, composite resin, dental room temperature polymerization resin, and resin model. It is practically used in materials and the like.

  Usually, when such a material is cured by radical polymerization, it is known that a dimensional change occurs due to polymerization shrinkage, which has been a problem in applications where the accuracy of the shape of the cured product is required. In particular, extremely high dimensional accuracy is required for tooth restorations and dentures in the above-described dental applications, and if this is not satisfied, poor compatibility, marginal retraction, and poor adhesion are caused.

  As a means for solving such a shrinkage problem, there is a method of suppressing the amount of radical polymerizable monomer used in the curable composition as much as possible, and a method of containing a large amount of filler accordingly. The operability is greatly lowered and the balance of physical properties is difficult to achieve, which is not practical.

Under these circumstances, the curable composition using a thermal polymerization initiator (curing agent) such as an organic oxide is blended with particles having a property of thermal expansion when exposed to a high temperature, and the curable composition is heated. When thermal polymerization is performed, it is proposed to relax the polymerization shrinkage by thermally expanding the thermally expandable particles (see Patent Document 1).
JP 2004-2719 A

  The method of blending the heat-expandable particles is extremely effective for reducing polymerization shrinkage in radical polymerization, but the disclosed method has not been satisfactory in the operability at the time of curing.

  That is, in the above method, since a radical polymerization initiator is used as a radical polymerization initiator, the curable composition is cured by heating to 80 to 140 ° C. from the outside by adopting a heating and pressing method or the like. It is carried out. Therefore, a large molding apparatus such as a press molding apparatus or an injection molding apparatus is used, and it is difficult to say that it is simple in terms of operability. This is not suitable for applications in which the cured product must be cured each time according to the required shape, and specifically, various complicated shapes such as dental applications depending on the patient's case. It could not be applied to applications where tooth restorations had to be individually cured. In particular, in the case of a dental curable composition used in the oral cavity, such as when a cured carious part is filled with a composite resin and cured, thermally expandable particles are added by external heating during such curing. A composition with an expansion method could not be used.

From the above background, it has been a big problem to develop a dental curable composition that is cured by a simple operation applicable to the oral cavity and in which polymerization shrinkage at that time is highly suppressed.

  The present inventors have continued intensive studies to solve the above problems. As a result, in the curable composition containing thermally expandable particles, the above problem can be solved by using a photopolymerization initiator or a redox polymerization initiator that initiates radical polymerization at a low temperature as a polymerization initiator. The headline and the present invention were completed.

That is, the present invention is a dental curable composition comprising (A) a radical polymerizable monomer, (B) a photopolymerization initiator and / or a redox polymerization initiator, and (C) a thermally expandable particle. is there.

  According to the curable composition of the present invention, at the time of curing, the thermally expandable particles are expanded, which relieves polymerization shrinkage of the radical polymerizable monomer, so that a cured resin body having a small dimensional change can be produced. It is. Particularly in dental applications, it is very effective in producing dentures, temporary restorations, and models with improved compatibility, edge deformation, and adhesion.

  Moreover, the curable composition of the present invention starts the radical polymerization in an atmosphere near room temperature without being subjected to external heating by a heater at the time of curing. Can be easily implemented with good operability. This is an extremely advantageous curing mode in a dental composition used in the oral cavity such as a composite resin.

  As the radically polymerizable monomer (A) used in the present invention, known ones can be used without any limitation. Examples of the radically polymerizable monomer that can be suitably used include monomers having an acryloyl group or a methacryloyl group, and specific examples of such radically polymerizable monomers include the monomers shown below.

  Monofunctional monomers such as methyl methacrylate (hereinafter abbreviated as MMA), ethyl methacrylate (hereinafter abbreviated as EMA), propyl methacrylate, butyl methacrylate, hydroxyethyl methacrylate, glycidyl methacrylate and their acrylates; EGDMA), polyethylene glycol dimethacrylate, vinyl monomer having a hydroxyl group (for example, methacrylates such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-chloro-2-hydroxypropyl methacrylate, etc., or these methacrylates) Acrylate) and diisocyanate compounds [eg hexamethylene diisocyanate, trimethylhexamethylene diisocyanate Diadducts obtained from addition with diisocyanate methylcyclohexane, isophorone diisocyanate, methylenebis (4-cyclohexylisocyanate)], for example 1,6-bis (methacrylethyloxycarbonylamino) -2,2-4-trimethylhexane, 1,6 Aliphatic difunctional monomers such as hexanediol dimethacrylate and these acrylates; 2,2-bis (4-methacryloxyethoxyphenyl) propane, 2,2-bis (4-methacryloxydiethoxyphenyl) propane, Aromatic bifunctional monomers such as 2,2-bis [4- (3-methacryloxy-2-hydroxypropoxy) -phenyl] propane; trimethylolpropane trimethacrylate (hereinafter abbreviated as TMPT), pentaerythritol tri And trifunctional monomers such as tacrylate and acrylates thereof; 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, glycidol dimethacrylate and monomers having a hydroxyl group such as acrylate and trimethylhexamethylene diisocyanate, diisocyanate methylcyclohexane, Urethane di (meth) acrylate monomers obtained from addition reaction with isocyanate compounds such as isophorone diisocyanate, hexamethylene diisocyanate, diisocyanate methylbenzene, and methylenebis (4-cyclohexyl isocyanate). Although the said radically polymerizable monomer may be used independently, two or more types can be mixed and used.

  The curable composition of the present invention thermally expands the thermally expandable particles of the component (C) described later by the polymerization heat generated by these radical polymerizable monomers. Therefore, as the radical polymerizable monomer, the larger the polymerization exotherm, the higher the effect of relaxing the polymerization shrinkage, and the more preferable. The type and blending amount are selected and blended so that the maximum polymerization temperature reached upon curing of the curable composition excluding the thermally expandable particles exceeds the thermal expansion start temperature of the thermally expandable particles. preferable. Preferably, the maximum value of the polymerization temperature reached at the time of curing exceeds the thermal expansion start temperature of the thermally expandable particles by 1 ° C. or more, more preferably 3 ° C. or more.

  From this point of view, the radical polymerizable monomer is preferably a polymerizable monomer having a polymerization enthalpy of −250 J / g or less, and in particular, a polymerizable monomer having a polymerization enthalpy of −350 J / g or less. It is preferable to use the body. In addition, when using 2 or more types of radically polymerizable monomers mixed, the said polymerization enthalpy is the average value of this polymerization enthalpy calculated | required from the value of the polymerization enthalpy of each monomer to mix, and those mixing ratios. You should evaluate.

  Further, in a system using a polymerizable monomer having a large number of polymerizable functional groups relative to its molecular weight, it is preferable because the heat generated by polymerization can be effectively utilized for the expansion of thermally expandable particles. In particular, a polymerizable monomer having a molecular weight per functional group in the range of 80 to 130 can be preferably used.

  Specific examples of the most preferred radical polymerizable monomer in the present invention that satisfies these particularly preferable conditions include MMA, EMA, EGDMA, TMPT, or a mixture thereof.

  In the curable composition of the present invention, (B) a photopolymerization initiator and / or a redox polymerization initiator is used as a polymerization initiator for initiating polymerization of the (A) radical polymerizable monomer. Photopolymerization can be carried out with good operability by using a handy light irradiator, and can be safely irradiated even in the oral cavity. On the other hand, a redox polymerization initiator is a chemical polymerization catalyst that forms a redox system and generates radicals by a combination of two or more compounds. The radical generation reaction is usually performed at an ambient temperature of about normal temperature, specifically, It proceeds smoothly even at 40 ° C or lower. Therefore, in the curable composition of the present invention using these polymerization initiators, the light irradiation and the mixing of the reagents can be performed in an atmosphere near room temperature without special external heating using a heater during curing. (A) polymerization of the radically polymerizable monomer is started, and when the radical polymerization is thus started, the heat of polymerization causes (C) thermal expansion of the thermally expandable particles, which will be described later. In addition, the target polymerization shrinkage can be reduced.

  As the photopolymerization initiator used in the present invention, known ones that generate radicals by light energy such as ultraviolet rays and visible rays can be used without limitation. Specifically, benzoin alkyl ethers such as benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether, benzyl ketals such as benzyldimethyl ketal and benzyl diethyl ketal, benzophenone, 4,4′-dimethylbenzophenone, 4-methacryloxy Benzophenones such as benzophenone, diacetyl, 2,3-pentadionebenzyl, camphorquinone, α-diketones such as 9,10-phenanthraquinone, 9,10-anthraquinone, 2,4-diethoxythioxanthone, Thioxanthone compounds such as 2-chlorothioxanthone and methylthioxanthone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis- (2,6-dichlorobenzoyl) phenylphosphite Oxide, bis- (2,6-dichlorobenzoyl) -2,5-dimethylphenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -4-propylphenylphosphine oxide, bis- (2,6-dichlorobenzoyl) ) -1-naphthylphosphine oxide, bisacylphosphine oxides such as bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, and the like can be used.

  In addition, a reducing agent is often added to the photopolymerization initiator as a polymerization initiation assistant. Examples thereof include 2- (dimethylamino) ethyl methacrylate, ethyl 4-dimethylaminobenzoate, and N-methyldiethanolamine. And aldehydes such as lauryl aldehyde, dimethylaminobenzaldehyde and terephthalaldehyde, and sulfur-containing compounds such as 2-mercaptobenzoxazole, 1-decanethiol, thiosalicylic acid and thiobenzoic acid. The amount used is generally 50 to 500 parts by weight per 100 parts by weight of the photopolymerization initiator.

  The photopolymerization initiator / reducing agent may be used alone or in combination of two or more. When the photopolymerization initiator is used in combination with a reducing agent, the content thereof, including the content thereof, is 0.01 to 5 parts by weight with respect to 100 parts by weight of the radical polymerizable monomer. The amount is preferably 0.1 to 1 part by weight.

  Moreover, as a redox polymerization initiator, the well-known polymerization initiator which forms a redox system and generate | occur | produces a radical by the combination of the said 2 or more types of compound can be employ | adopted without a restriction | limiting. Therefore, when a redox polymerization initiator as a polymerization initiator is adopted, the curable composition needs to separate the two types of compounds forming the redox system during storage, and the packaging form is usually 2 Divided into units or more.

  For example, a peroxide can be used in combination with a curing accelerator represented by an amine or a salt thereof. Specific examples of the peroxide include dibenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, and dilauroyl peroxide. As the amine, a secondary or tertiary amine in which an amine is bonded to an aryl group is preferably used. Examples thereof include N, N-dimethylaniline, N, N-dimethyl-p-toluidine, p-tolyldiethanolamine and the like. The blending ratio of the peroxide to a curing accelerator typified by an amine or a salt thereof is preferably in the range of 0.1 to 5 parts by weight of the curing accelerator with respect to 1 part by weight of the peroxide.

  Another example of the redox polymerization initiator includes a combination of a borate compound and an acid. As the borate compound, those having at least one boron-aryl bond in one molecule are preferable from the viewpoint of storage stability. Specific examples of suitably used aryl borate compounds include borate compounds having one aryl group in one molecule (hereinafter also referred to as monoaryl borate): trialkylphenyl boron, trialkyl (p -Chlorophenyl) boron, trialkyl (p-fluorophenyl) boron, trialkyl (m-butylphenyl) boron, sodium salt, potassium salt, tetrabutylammonium salt of ethyl, trialkyl (m-butyloxyphenyl) boron, ethyl A pyridinium salt etc. can be mentioned. Here, specific examples of the alkyl group include an n-butyl group, an n-octyl group, and an n-dodecyl group. Examples of the borate compound having two aryl groups in one molecule include dialkyldiphenyl boron, dialkyldi (p-chlorophenyl) boron, dialkyldi (p-fluorophenyl) boron, dialkyldi (m-butylphenyl) boron, and dialkyldi ( m-butyloxyphenyl) boron sodium salt, potassium salt, tetrabutylammonium salt, ethylpyridinium salt and the like. In addition, as an alkyl group in these compounds, the thing similar to the alkyl group in a monoaryl borate is illustrated. Further, borate compounds having three aryl groups in one molecule include monoalkyltriphenylboron, monoalkyltri (p-chlorophenyl) boron, monoalkyltri (p-fluorophenyl) boron, monoalkyltri (p -Butylphenyl) boron, monoalkyltri (m-butylphenyl) boron, sodium salt, potassium salt, tetrabutylammonium salt, ethylpyridinium salt of monoalkyltri (m-butyloxyphenyl) boron and the like. In addition, as an alkyl group in these compounds, the thing similar to the alkyl group in a monoaryl borate is illustrated. Examples of borate compounds having four aryl groups in one molecule include tetraphenyl boron, tetrakis (p-chlorophenyl) boron, tetrakis (p-fluorophenyl boron, tetrakis (p-nitrophenyl) boron, tetrakis (m-butyl). Phenyl) boron, tetrakis (m-octyloxyphenyl) boron, tetrakis (m-butyloxyphenyl) boron, tetrakis (m-octyloxyphenyl) boron, (m-butyloxyphenyl) triphenylboron, (m-octyloxy) Phenyl) triphenylboron sodium salt, potassium salt, tetrabutylammonium salt, ethylpyridinium salt, etc. These borate compounds can be used alone or in combination of two or more.

  The acid is not particularly limited, and inorganic acids such as hydrochloric acid, nitric acid, sulfuric acid and phosphoric acid, organic acids such as acetic acid, maleic acid, citric acid, malonic acid, oxalic acid, propanesulfonic acid, benzenesulfonic acid and toluenesulfonic acid Can be used.

  The blending ratio of the borate compound and the acid is preferably in the range of 0.5 to 100 parts by weight with respect to 1 part by weight of the borate compound.

  Another example of a redox polymerization initiator includes a combination of a pyrimidinetrione derivative, a halogen ion forming compound, and a cupric or ferric ion forming compound.

  Specific examples of pyrimidinetrione derivatives include N-cyclohexyl 5-ethylpyrimidinetrione, 1-benzyl5-phenylpyrimidinetrione, 5-butylpyrimidinetrione, 5-phenylpyrimidinetrione, 1,3-dimethylpyrimidinetrione, 5-ethyl. There are pyrimidine trions. Among these, N-cyclohexyl 5-ethylpyrimidinetrione is particularly excellent, but these may be used alone or in combination. Suitable halogen ion forming compounds include dilauryldimethylammonium chloride, lauryldimethylbenzylammonium chloride, benzyltrimethylammonium chloride, diisobutylamine hydrochloride, tetra-n-butylammonium chloride, triethylamine hydrochloride, trimethylamine hydrochloride, dimethylamine hydrochloride. Chloride, diethylamine hydrochloride, methylamine hydrochloride, ethylamine hydrochloride, isobutylamine hydrochloride, triethanolamine hydrochloride, β-phenylethylamine hydrochloride, acetylcholine chloride, 2-chlorotrimethylamine hydrochloride, (2-chloroethyl Triethylammonium chloride, tetra-decyldimethylbenzylammonium chloride, tetraethylammonium chloride, tetramethylammonium chloride, trioctylmethylammonium chloride, benzyldimethylcetylammonium chloride, benzyldimethylstearylammonium chloride, dilauryldimethylammonium bromide, tetrabutylammonium bromide, Examples thereof include benzyltriethylammonium bromide, and these may be used alone or in combination.

  Examples of cupric or ferric ion forming compounds that can be suitably used include acetylacetone copper, cupric acetate, copper oleate, acetylacetone iron, etc., and these may be used alone or in combination. May be.

  As the compounding ratio, the compounding ratio of the halogen ion forming compound may be used in the range of 0.001 to 0.5 parts by weight, preferably in the range of 0.05 to 0.3 parts by weight with respect to 1 part by weight of the pyrimidinetrione derivative. Is preferably used. Further, the compounding ratio of the cupric or ferric ion forming compound may be used in the range of 0.0001 to 0.05 parts by weight with respect to 1 part by weight of the pyrimidinetrione derivative, preferably 0.001 to 0.01. It is preferable to use within a range.

  The compounding amount of the above redox polymerization initiator may be used in the range of 0.05 to 15 parts by weight, preferably in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the radical polymerizable monomer. Is preferred.

  The (C) thermally expandable particles used in the present invention are powders having a property that their volume expands when heated, and any known particles can be used without any limitation. As described above, the heat-expandable particles are thermally expanded by the heat generated by the polymerization of the radically polymerizable monomer (A), even if no external heating is applied when the curable composition is cured. Demonstrate the effect.

  Here, in the present invention, the heat-expandable particles are particles whose volume is expanded by heating twice or more, preferably 5 to 100 times. The thermal expansion start temperature is not particularly limited, and is generally 60 to 160 ° C., but 70 to 100 ° C. is particularly preferable in consideration of the efficiency of thermal expansion due to polymerization heat generation. Moreover, as a particle size of a thermally expansible particle, a thing with an average particle diameter of about 5-50 microns is preferable from a viewpoint of operativity or uniform expansibility.

  Examples of such thermally expandable particles include those in which a liquefied gas is enclosed in hollow particles made of a thermoplastic resin. When the particles are heated, the hollow particles that form the outer shell are softened by heating, and the liquefied gas sealed therein is gasified to expand the volume.

  As the thermoplastic resin forming the hollow powder, those having gas barrier properties are preferable, and specific examples include (meth) acrylic resin, acrylonitrile resin, vinylidene chloride resin, nylon resin, polyethylene naphthalate and the like. . On the other hand, the liquefied gas sealed in the hollow powder is, for example, a chlorine-containing fluorine-based gas such as trichlorofluoromethane, dichlorofluoromethane, dichlorofluoroethane, dichlorotrifluoroethane, trichlorotrifluoroethane, or dichloropentafluoropropane. Organic compounds, hydrocarbons such as n-pentane, isopentane, neopentane, butane, isobutane, hexane, petroleum ether, and chlorinated hydrocarbons such as methyl chloride, dichloroethylene, trichloroethane, and trichloroethylene. In such particles, the thermal expansion start temperature can be adjusted by adjusting the thermal deformation temperature of the thermoplastic resin forming the hollow powder and the temperature at which the encapsulated liquefied gas is vaporized. The thermoplastic resin that forms the hollow powder is preferably one that does not easily dissolve or swell in a liquid component containing a radical polymerizable monomer as a main component. The shape of the hollow powder is not particularly limited, but is usually spherical or substantially spherical.

  The thermally expandable particles may be composed of a plurality of different layers. Moreover, you may use these thermally expansible particles 1 type or in mixture of 2 or more types.

  If the amount of the heat-expandable particles is too small, the effect of alleviating polymerization shrinkage of the curable composition is small. On the other hand, if the amount is too large, the cured product is easily broken. The amount is preferably 1 to 80 parts by weight and more preferably 2 to 20 parts by weight with respect to parts by weight.

  In the present invention, when the curable composition is used for a composite resin or a room temperature polymerization resin for dental use, the operability of the curable composition is improved, or sufficient mechanical strength is imparted to the cured resin body. Therefore, it is preferable to add the filler (D) as an optional component. As such a filler, known ones such as organic powders, inorganic powders, organic-inorganic composite powders, or mixtures thereof can be used without any limitation.

  Specific examples of organic powders include polymethyl methacrylate, polyethyl methacrylate, polybutyl methacrylate, copolymers of methyl methacrylate and ethyl methacrylate, copolymers of ethyl methacrylate and isobutyl methacrylate, vinyl chloride and vinyl acetate. And acrylonitrile-butadiene-styrene copolymer, polyacetal, polycarbonate and the like. In addition, when the filler is a resin filler, the molecular weight of the resin filler is not particularly limited, but generally a molecular weight of 5,000 to 1,000,000 is preferable. When the resin filler is a filler made of a copolymer, the copolymerization ratio and the like are not particularly limited.

  Specific examples of the inorganic powder include pulverized quartz, silica, alumina, aluminofluorosilicate glass, and the like. The organic-inorganic composite powder can be obtained, for example, by dispersing the inorganic powder exemplified above in a resin, curing it, and crushing it to an appropriate size.

  The shape of the filler is not particularly limited, and may be pulverized particles or spherical particles obtained by normal pulverization. The particle size of the filler is not particularly limited, but generally a particle having a particle size of 0.01 to 200 μm is preferable.

  The blending amount of these fillers is preferably in the range of 50 to 400 parts by weight with respect to 100 parts by weight of the radical polymerizable monomer from the viewpoint of operability and cured body strength. The amount of the resin filler used when the curable composition of the present invention is used for a dental room temperature polymerization resin is in the range of 100 to 300 parts by weight with respect to 100 parts by weight of the polymerizable monomer. Is preferred.

  Other components can be added to the curable composition of the present invention as necessary. Specific examples include organic solvents such as ethanol, polymerization inhibitors such as butylhydroxytoluene and methoxyhydroquinone, and ultraviolet absorbers such as 4-methoxy-2-hydroxybenzophenone and 2- (2-benzotriazole) -p-cresol. , Etc., and other components such as dyes, pigments, and fragrances can be added. In addition, 2,4-diphenyl-4-methyl-1-methyl-1-pentene may be added for the purpose of adjusting the curing time or suppressing the occurrence of cracks in the cured body during curing. The blending amount at this time is preferably 0.01 to 10 parts by weight with respect to 100 parts by weight of the radical polymerizable monomer.

  The curable composition of the present invention can greatly reduce shrinkage during curing compared to conventional curable compositions, and is excellent in operability such as formability and kneadability. It is very useful for various materials such as adhesives, composite resins, dental room temperature polymerization resins, and model materials. Among these dental materials, when applied to those that are cured in the oral cavity, the effect of the present invention for curing without external heating is particularly remarkable.

  When using the composition according to the present invention as a model material, for example, (A) a radical polymerizable monomer, (B) a photopolymerization initiator, and (C) a predetermined amount of thermally expandable particles may be mixed and manufactured. preferable. The curable composition thus obtained may be stored in a light-shielding container for storage and distribution. When using, an impression is extract | collected using a dental impression material etc., the said model material composition is poured into this, it superposes | polymerizes and cures by performing light irradiation, and a model is produced. As another method of use, (A) a radically polymerizable monomer, (B) a liquid component unit comprising the first component of a redox polymerization initiator, (A) a radically polymerizable monomer, (B It is also possible to provide a two-packaging form comprising a liquid component unit comprising a second component of redox polymerization initiator and (C) thermally expandable particles. The curable composition thus obtained may be stored in a light-shielding container and stored and distributed. When used, an impression is collected using a dental impression material or the like, and the two liquid components are mixed with this using a mixing chip or the like, and poured into a mold to be polymerized and cured to prepare a model.

  When the composition according to the present invention is used as a dental room temperature polymerization resin, (A) a radically polymerizable monomer, (B) a liquid component unit comprising a first component of a redox polymerization initiator, B) It is preferable to prepare in a two-packaging form consisting of a powder component unit comprising a second component of a redox polymerization initiator, (C) thermally expandable particles, and (D) a filler. Specific examples include a powder material in which a mixture of a resin-based filler such as polymethyl methacrylate and thermally expandable particles is mixed with a peroxide, and a radical polymerizable monomer such as methyl methacrylate. And a system in which a liquid material containing a group III tertiary amine is combined.

  The curable composition of the present invention can be used basically in the same manner as in the conventional methods of using temporary restoration materials and denture base lining materials. Using this as a temporary restoration material as an example of a method for producing a temporary crown as a specific example, after abutment formation on a tooth, a liquid material consisting of a methacrylic acid ester monomer, a tertiary amine, A powder material composed of polyethyl methacrylate powder, acrylonitrile resin-based thermally expandable particles, and benzoyl peroxide (BPO) is mixed. At this time, if the powder material: liquid material is collected at a ratio of 2: 1 and mixed, the resin mud becomes a putty-like paste. This putty-like paste is shaped into a cube, pressed against the abutment tooth that formed the putty-like resin mass, adjusted for occlusion and outline, then removed from the abutment tooth, and the outline is trimmed with scissors etc. Return to the base tooth. Removed when elasticity due to the polymerization reaction appears, and after complete curing, the surface is polished to complete the temporary crown. This completed temporary restoration is temporarily used in the oral cavity until it is attached to the abutment tooth using temporary cement and a permanent prosthesis such as a metal crown is attached.

  In the case of a denture base lining material, a liquid containing a plasticizer such as dibutyl phthalate is used, but the method of use is basically the same. Similar to the above operation, when it becomes a putty-like (butterfly-like) paste, it may be adhered to the back surface of the denture base.

Examples and comparative examples relating to the present invention are shown below, but the present invention is not limited to these examples. Evaluation was performed by the following method.
(1) Dimensional change: Powder material and liquid material are mixed in a ratio of 2: 1 on a SUS abutment having a shape with an upper base diameter of φ5 mm, a lower base diameter of φ6 mm, a height of 5 mm, and a base diameter of φ8 mm. The putty-like paste of the curable composition was pressed against the abutment while adjusting the shape at 23 ° C., removed from the abutment tooth after adjusting the outer shape, and removed when the elasticity due to the polymerization reaction appeared. Was trimmed with scissors to make a temporary crown. After 1 hour, it was placed on the abutment again, and the length of the gap between the pedestal and the periphery of the cured body was measured using an optical microscope and obtained as an average value of four points.
(2) Polymerization temperature: It was carried out by an exothermic method using a thermistor thermometer. First, each component was mixed at a predetermined ratio without containing (C) thermally expandable particles. For a redox polymerization initiator system consisting of two liquids or two components of powder and liquid, the two components are mixed, kneaded for 20 seconds, then poured into a glass container of φ15 mm × 30 mm, and then rolled with aluminum foil. The maximum temperature was measured with a recorder. For the photopolymerization initiator system, which is a single component, after pouring into a glass container of φ15 mm × 30 mm, insert a thermocouple wrapped with aluminum foil, and irradiate with a dental visible light irradiator for 3 minutes, The maximum temperature was measured with a recorder. The measurement was performed in a constant temperature room at 23 ° C.
(3) Suitability: An impression of the shape of a tooth is obtained with a dental impression material. For a one-pack type, a curable composition is poured into a mold, and light is applied for 3 minutes at 23 ° C. using a dental light irradiator. After being cured by irradiation and mixing two equivalents of the two-component one, after pouring the curable composition into a mold and leaving it to stand at 23 ° C. until cured, the ease of removal from the mold is indicated by the following index: It was evaluated with.
○: Good compatibility and does not easily come off.

        X: A gap is generated between the mold and the cured body, and it is easily removed.

  Next, Table 1 shows the abbreviations of the compounds used in Examples and Comparative Examples of the present invention.

Examples 1-6 and Comparative Examples 1-3
A curable composition comprising a liquid and a powder whose polymerization initiator is a redox polymerization initiator of each composition shown in Table 2 is prepared, and both are in a powder-liquid ratio 2 (weight ratio of powder to liquid: P / L). After mixing, the polymerization temperature and dimensional change were evaluated. The results are shown in Table 2.

Example 7
A one-component curable composition having a composition shown in Table 3 in which the polymerization initiator is a photopolymerization initiator was prepared, and the polymerization temperature and compatibility were evaluated. The results are shown in Table 3.
Examples 8-10
The liquid of each composition shown in Table 3 is prepared, the two-component curable composition whose polymerization initiator is a redox polymerization initiator is prepared, and the liquid material 1 and the liquid material 2 are mixed at a ratio of 2: 1. The polymerization temperature and compatibility were evaluated. The results are shown in Table 3.
Comparative Example 4
A one-component curable composition in which the polymerization initiator having the composition shown in Table 3 was a photopolymerization initiator was prepared, and the polymerization temperature and compatibility were evaluated. The results are shown in Table 3.
Comparative Example 5
A two-part curable composition liquid having a composition shown in Table 3 in which the polymerization initiator is a redox polymerization initiator is prepared. The suitability was evaluated. The results are shown in Table 3.

Claims (4)

A dental curable composition comprising (A) a radical polymerizable monomer, (B) a photopolymerization initiator and / or a redox polymerization initiator, and (C) thermally expandable particles. The dental curable composition according to claim 1, wherein (C) the thermally expandable particles are obtained by encapsulating a liquefied gas in hollow particles made of a thermoplastic resin. 3. The dental curable composition according to claim 1, wherein the dental curable composition is used without being substantially heated by a heater during curing. The dental curable composition according to claim 3, wherein the radically polymerizable monomer (A) is a polymerizable monomer having a polymerization enthalpy of -250 J / g or less.