Dental adhesive composition

Abstract

To provide a dental adhesive composition that does not show a decrease in strength over time in a wet environment.SOLUTION: The present invention is a two-agent dental adhesive composition containing a first agent and a second agent. The first agent contains: a (meth)acrylate compound having one or more acid groups; a (meth)acrylate compound having no acid group; water; and a water-soluble organic solvent. The second agent contains: a polyfunctional (meth)acrylate compound; a photopolymerization initiator; and 0 to 50 mass% of filler. Both the first agent and the second agent are substantially free of 2-hydroxyethyl methacrylate.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a dental adhesive composition. [Background technology]

[0002] It is known that two-component dental adhesive compositions exhibit better adhesive strength to both tooth structure and composite resin than one-component dental adhesive compositions. Such adhesive strength is achieved by applying a first component containing an acidic compound and water to the target, acid-etching the target, removing water not involved in adhesion by air blowing, applying a second component containing a polymerizable monomer and a photopolymerization initiator, and irradiating with light.

[0003] As a two-component dental adhesive composition, for example, a dental adhesive system has been disclosed that is composed of a primer composition consisting of a polymerizable monomer having an acidic group, a polymerizable monomer having a hydroxyl group, and water, and a bonding composition consisting of an acylphosphine oxide-based photopolymerization initiator and a polymerizable monomer (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-016911 Summary of the Invention [Problem to be solved by the invention]

[0005] Conventional two-component dental adhesive compositions have the problem that their strength decreases over time in a humid environment.

[0006] An object of the present invention is to provide a dental adhesive composition whose strength does not decrease over time in a humid environment. [Means for solving the problem]

[0007] A dental adhesive composition according to one embodiment of the present invention is a two-component dental adhesive composition comprising a first component and a second component, wherein the first component is 5 to 20% by mass a (meth)acrylate compound having an acid group, 5 to 20% by mass The composition contains a (meth)acrylate compound having no acid group, water, and a water-soluble organic solvent, the (meth)acrylate compound having an acid group is 10-(meth)acryloyloxydecyl dihydrogen phosphate and / or 4-(meth)acryloyloxyethyl trimellitic anhydride, and the (meth)acrylate compound not having an acid group is 2-hydroxy-1,3-dimethacryloyloxypropane and / or triethylene glycol dimethacrylate; The second agent is 60 to 95% by mass The composition contains a polyfunctional (meth)acrylate compound, a photopolymerization initiator, 2 to 4 mass% of a tertiary amine, and 0 to 50 mass% of a filler, the polyfunctional (meth)acrylate compound is at least one selected from bisphenol A diglycidyl methacrylate, 2-(4-(meth)acryloyloxydiethoxyphenyl)-2-(4-(meth)acryloyloxytriethoxyphenyl)propane, 1,6-bis-[2-methacryloyloxyethoxycarbonylamino]-2,4,4-trimethylhexane, 2-hydroxy-1,3-dimethacryloyloxypropane, triethylene glycol dimethacrylate, and neopentyl glycol dimethacrylate; The first agent and the second agent do not substantially contain 2-hydroxyethyl methacrylate, and the pH of the first agent is 1.5 to 2.0. and the polymerization rate of the cured product of the dental adhesive composition is 75 to 79.2%. . [Effects of the Invention]

[0008] According to one aspect of the present invention, it is possible to provide a dental adhesive composition whose strength does not decrease over time in a humid environment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail.

[0010] <Dental adhesive composition> The dental adhesive composition according to this embodiment is a two-component dental adhesive composition comprising a first component and a second component.

[0011] <First agent> In the two-component dental adhesive composition, the first component is also called a pretreatment agent or a primer, and contains a (meth)acrylate compound having an acid group, a (meth)acrylate compound not having an acid group, water, and a water-soluble organic solvent, and is substantially free of 2-hydroxyethyl methacrylate.

[0012] In this specification, the term "(meth)acrylate" refers to at least one selected from acrylate and methacrylate.

[0013] <(Meth)acrylate Compound Having an Acid Group> The (meth)acrylate compound having an acid group is not particularly limited, but examples thereof include (meth)acrylates having a phosphoric acid group, (meth)acrylates having a pyrophosphate group, (meth)acrylates having a carboxyl group, (meth)acrylates having a thiophosphate group, (meth)acrylates having a sulfonic acid group, and (meth)acrylates having a phosphonic acid group.

[0014] Examples of (meth)acrylates having a phosphate group include 2-(meth)acryloyloxyethyl dihydrogen phosphate, bis[2-(meth)acryloyloxyethyl]hydrogen phosphate, 2-(meth)acryloyloxyethylphenyl hydrogen phosphate, 6-(meth)acryloyloxyhexyl dihydrogen phosphate, 6-(meth)acryloyloxyhexylphenyl hydrogen phosphate, 10-(meth)acryloyloxydecyl dihydrogen phosphate (hereinafter sometimes abbreviated as MDP), 1,3-di(meth)acryloylpropane-2-dihydrogen phosphate, 1,3-di(meth)acryloylpropane-2-phenyl hydrogen phosphate, bis[5-{2-(meth)acryloyloxyethoxycarbonyl}heptyl]hydrogen phosphate, and acid chlorides, alkali metal salts, and ammonium salts thereof. Among these, 10-methacryloyloxy is the most popular in terms of initial adhesion. Desirji Hydrogen phosphate (MDP) is preferred.

[0015] Examples of (meth)acrylates having a pyrophosphate group include bispyrophosphate [ 2-(meth)acryloyloxyethyl ] , bispyrophosphate [ 4-(meth)acryloyloxybutyl ] , bispyrophosphate [ 6-(meth)acryloyloxyhexyl ] , bispyrophosphate [ 8-(meth)acryloyloxyoctyl ], bispyrophosphate [ 10-(meth)acryloyloxydecyl ] and the like, and their acid chlorides, alkali metal salts, and ammonium salts.

[0016] Examples of (meth)acrylates having a carboxyl group include 4-(meth)acryloyloxyethyl trimellitic acid (hereinafter sometimes abbreviated as 4-MET), 4-(meth)acryloyloxyethyl trimellitic anhydride (hereinafter sometimes abbreviated as 4-META), 4-(meth)acryloyloxydecyl trimellitic acid, 4-(meth)acryloyloxydecyl trimellitic anhydride, 11-(meth)acryloyloxy-1,1-undecanedicarboxylic acid, 1,4-di(meth)acryloyloxypyromellitic acid, 2-(meth)acryloyloxyethyl maleic acid, 2-(meth)acryloyloxyethyl phthalic acid, 2-(meth)acryloyloxyethyl hexahydrophthalic acid, etc. Among these, 4-(meth)acryloyloxyethyl trimellitic anhydride (4-META) is preferred in terms of initial adhesion.

[0017] Examples of (meth)acrylates having a thiophosphate group include: 、2-(meth)acryloyloxyethyl dihydrogenthiophosphate, 3-(meth)acryloyloxypropyl dihydrogenthiophosphate, 4-(meth)acryloyloxybutyl dihydrogenthiophosphate, 5-(meth)acryloyloxypentyl dihydrogenthiophosphate, 6-(meth)acryloyloxyhexyl dihydrogenthiophosphate, 7-(meth)acryloyloxyheptyl dihydrogenthiophosphate, 8-(meth)acryloyloxyoctyl dihydrogenthiophosphate, 9-(meth)acryloyloxynonyl dihydrogenthiophosphate, 10-(meth)acryloyloxydecyl dihydrogenthiophosphate (hereinafter sometimes abbreviated as MDTP), 11-(meth)acryloyloxyundecyl dihydrogenthiophosphate, 1 Examples of the acryloyloxypropyl methyl ester include 2-(meth)acryloyloxydodecyl dihydrogen thiophosphate, 13-(meth)acryloyloxytridecyl dihydrogen thiophosphate, 14-(meth)acryloyloxytetradecyl dihydrogen thiophosphate, 15-(meth)acryloyloxypentadecyl dihydrogen thiophosphate, 16-(meth)acryloyloxyhexadecyl dihydrogen thiophosphate, 17-(meth)acryloyloxyheptadecyl dihydrogen thiophosphate, 18-(meth)acryloyloxyoctadecyl dihydrogen thiophosphate, 19-(meth)acryloyloxynonadecyl dihydrogen thiophosphate, and 20-(meth)acryloyloxyicosyl dihydrogen thiophosphate, as well as acid chlorides, alkali metal salts, and ammonium salts thereof. Among these, 10-(meth)acryloyloxydecyl dihydrogen thiophosphate (MDTP) is preferred in terms of initial adhesiveness.

[0018] Examples of the (meth)acrylate having a sulfonic acid group include 2-(meth)acrylamido-2-methylpropanesulfonic acid, styrenesulfonic acid, and 2-sulfoethyl (meth)acrylate.

[0019] Examples of the (meth)acrylate having a phosphonic acid group include 2-(meth)acryloyloxyethylphenylphosphonate, 5-(meth)acryloyloxypentyl-3-phosphonopropionate, and 6-(meth)acryloyloxyhexyl-3-phosphonopropionate. Examples of the acryloyloxydecyl ester include 10-(meth)acryloyloxydecyl-3-phosphonopropionate, 10-(meth)acryloyloxyhexyl-3-phosphonoacetate, 6-(meth)acryloyloxyhexyl-3-phosphonoacetate, 10-(meth)acryloyloxydecyl-3-phosphonoacetate, and acid chlorides, alkali metal salts, and ammonium salts thereof.

[0020] These (meth)acrylate compounds having an acid group may be used in combination of two or more kinds.

[0021] The content of the (meth)acrylate having an acid group in the first agent is not particularly limited, but is, for example, 5 to 30% by mass, and preferably 10 to 20% by mass, relative to 100% by mass of the first agent. When the content of the (meth)acrylate having an acid group in the first agent is 5 to 30% by mass, the initial adhesiveness of the dental adhesive composition is improved.

[0022] <(Meth)acrylate Compounds Having No Acid Group> The (meth)acrylate compound having no acid group is not particularly limited, and examples thereof include di(meth)acrylate compounds. Preferred di(meth)acrylate compounds include di(meth)acrylate compounds having a molecular weight of less than 400, such as 2-hydroxy-1,3-dimethacryloyloxypropane, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol #200 dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, 1,10-decanediol dimethacrylate, and neopentyl glycol dimethacrylate. Two or more of these (meth)acrylate compounds having no acid group may be used in combination.

[0023] The content of the (meth)acrylate compound having no acid group in the first agent is not particularly limited, but is, for example, 1 to 40% by mass, and preferably 5 to 25% by mass, relative to 100% by mass of the first agent. When the content of the (meth)acrylate compound having no acid group in the first agent is 1 to 40% by mass, the adhesiveness of the dental adhesive composition is improved, and the mechanical strength of the cured product of the dental adhesive composition is improved.

[0024] <Water> The water is not particularly limited, but preferably ion-exchanged water or distilled water is used. When the first agent contains water, the acid group of the (meth)acrylate having an acid group dissociates, improving the solubility of the smear layer on the tooth surface, the tooth demineralization ability of the dental adhesive composition as a primer, and the penetration into the tooth. Therefore, when the tooth surface is pretreated with the first agent, the penetration into the tooth of the dental adhesive composition as a primer is improved, and the adhesion of the dental adhesive composition is improved.

[0025] The content of water in the dental composition is not particularly limited, and is preferably 1 to 50% by mass, and more preferably 5 to 40% by mass, relative to 100% by mass of the first agent. When the content of water in the dental composition is 1 to 50% by mass, the solubility of the smear layer on the tooth surface and the tooth demineralization properties and penetration into the tooth as a primer of the dental adhesive composition are improved.

[0026] <Water-soluble organic solvent> The water-soluble organic solvent is not particularly limited, but examples thereof include methanol, ethanol, propanol, isopropanol, butanol, pentanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene, ethyl acetate, butyl acetate, cellosolve, tetrahydrofuran, dioxane, dichloromethane, chloroform, carbon tetrachloride, trichloroethylene, dimethylformamide, and dimethyl sulfoxide. Two or more of these water-soluble organic solvents may be used in combination. Among these, ethanol, acetone, isopropanol, and butanol are preferred.

[0027] The content of the water-soluble organic solvent in the first agent is not particularly limited, but is, for example, 10 to 50% by mass, and preferably 20 to 40% by mass, relative to 100% by mass of the first agent. When the content of the water-soluble organic solvent in the dental adhesive composition is 10% by mass or more, the uniformity of the dental composition is improved, and when it is 50% by mass or less, the adhesiveness of the dental adhesive composition as a primer is improved.

[0028] <Other ingredients> The first agent may further contain a photopolymerization initiator, a tertiary amine, a polymerization inhibitor, and a filler.

[0029] The photopolymerization initiator is not particularly limited, and examples thereof include α-diketone compounds such as camphorquinone, acylphosphine oxide compounds such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethoxybenzoyldiphenylphosphine oxide, 2,6-dimethylbenzoyldiphenylphosphine oxide, and 2,6-dimethoxybenzoyldiphenylphosphine oxide, benzil ketal, diacetyl ketal, benzil dimethyl ketal, benzil diethyl ketal, benzil bis(2-methoxyethyl) ketal, 4,4'-dimethyl(benzil dimethyl ketal), anthraquinone, 1-chloroanthraquinone, 2-chloroanthraquinone, 1,2-benzanthraquinone, and 1-hydroxyanthraquinone. Examples of the photopolymerization initiator include quinone, 1-methylanthraquinone, 2-ethylanthraquinone, 1-bromoanthraquinone, thioxanthone, 2-isopropylthioxanthone, 2-nitrothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, 2-chloro-7-trifluoromethylthioxanthone, thioxanthone-10,10-dioxide, thioxanthone-10-oxide, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzophenone, bis(4-dimethylaminophenyl)ketone, 4,4'-bis(diethylamino)benzophenone, and compounds containing an azide group. Two or more of these photopolymerization initiators may be used in combination.

[0030] The content of the photopolymerization initiator in the first agent is not particularly limited, but is, for example, 0.01 to 5% by mass, and preferably 2 to 4% by mass, relative to 100% by mass of the first agent. When the content of the photopolymerization initiator in the first agent is 0.01 to 5% by mass, the adhesiveness of the dental adhesive composition is improved, and the storage stability of the dental adhesive composition as a primer is improved.

[0031] The tertiary amine can function as a polymerization accelerator. The tertiary amine is not particularly limited, but preferred examples include aromatic tertiary amines such as ethyl 4-dimethylaminobenzoate. When a tertiary amine is contained, the content of the tertiary amine in the first agent is not particularly limited, but is, for example, 0.01 to 3% by mass, preferably 0.1 to 1% by mass, relative to 100% by mass of the first agent.

[0032] The polymerization inhibitor is not particularly limited, and examples thereof include dibutylhydroxytoluene, 2,6-t-butyl-2,4-xylenol, etc. When a polymerization inhibitor is contained, the content of the polymerization inhibitor in the first agent is not particularly limited, and is, for example, 0.01 to 3 mass % and preferably 0.1 to 1 mass % relative to 100 mass % of the first agent.

[0033] The filler is not particularly limited, but is preferably an inorganic filler, and examples thereof include colloidal silica, fine particle silica whose surface has been hydrophobized, aluminum oxide, etc. When a filler is contained, the content of the filler in the first agent is not particularly limited, but is, for example, 0.01 to 30% by mass, and preferably 0.1 to 10% by mass, relative to 100% by mass of the first agent.

[0034] <Excluded ingredients in the first drug>

[0035] The first agent is substantially free of 2-hydroxyethyl methacrylate (hereinafter sometimes abbreviated as HEMA). In this specification, "substantially free" means that target components such as HEMA are not intentionally blended. Note that a target component that is "substantially free" may be contained as an unavoidable impurity. Note that when the target component is contained as an unavoidable impurity, the content of the target component is preferably less than 1%.

[0036] If the first agent substantially contains 2-hydroxyethyl methacrylate (HEMA), the strength of the cured layer of the dental adhesive composition will decrease over time due to water absorption. In contrast, in this embodiment, the first agent does not substantially contain 2-hydroxyethyl methacrylate (HEMA), so that the strength of the cured layer of the dental adhesive composition can be prevented from decreasing over time due to water absorption.

[0037] Furthermore, for the same reasons as for 2-hydroxyethyl methacrylate (HEMA), it is preferable that the first agent does not substantially contain monofunctional (meth)acrylate compounds having a hydroxyl group, such as 2,3-dihydroxypropyl methacrylate, and monofunctional (meth)acrylamides, such as N,N-diethylacrylamide.

[0038] The first agent preferably has a pH of 1.2 to 2.0, more preferably 1.5 to 2.0. By adjusting the pH of the first agent to 1.2 to 2.0, the solubility of the smear layer on the tooth surface and the demineralization of tooth tissue are improved, and the adhesiveness of the dental adhesive composition is improved.

[0039] <Second agent> In the two-component dental adhesive composition, the second component is also called a bonding agent (or bond), and contains a polyfunctional (meth)acrylate compound, a photopolymerization initiator, and 0 to 50% by mass of a filler, and is substantially free of 2-hydroxyethyl methacrylate (HEMA).

[0040] <Polyfunctional (meth)acrylate compounds> The polyfunctional (meth)acrylate compound in the second agent is not particularly limited, but is preferably a di(meth)acrylate compound, and more preferably contains a di(meth)acrylate compound having a molecular weight of 400 or more and a di(meth)acrylate compound having a molecular weight of less than 400.

[0041] Examples of di(meth)acrylate compounds having a molecular weight of 400 or more include aliphatic di(meth)acrylate compounds having a molecular weight of 400 or more, and aromatic di(meth)acrylate compounds having a molecular weight of 400 or more.

[0042] Specific examples of aliphatic di(meth)acrylate compounds having a molecular weight of 400 or more include 1,6-bis-[2-methacryloyloxyethoxycarbonylamino]-2,4,4-trimethylhexane (UDMA), polyethylene glycol #400 dimethacrylate, polyethylene glycol #600 dimethacrylate, and polyethylene glycol #1000 dimethacrylate.

[0043] Specific examples of aromatic di(meth)acrylate compounds having a molecular weight of 400 or more include bisphenol A diglycidyl methacrylate (Bis-GMA), 2-(4-(meth)acryloyloxydiethoxyphenyl)-2-(4-(meth)acryloyloxytriethoxyphenyl)propane, 2-(4-(meth)acryloyloxydipropoxyphenyl)-2-(4-(meth)acryloyloxytriethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxypropoxyphenyl)propane, and 2,2-bis(4-(meth)acryloyloxyisopropoxyphenyl)propane.

[0044] The di(meth)acrylate compound having a molecular weight of less than 400 is not particularly limited, but is preferably a di(meth)acrylate compound having a molecular weight of less than 300.

[0045] Examples of di(meth)acrylate compounds having a molecular weight of less than 300 include 2-hydroxy-1,3-dimethacryloyloxypropane, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol #200 dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, 1,10-decanediol dimethacrylate, neopentyl glycol dimethacrylate, etc. Among these, 2-hydroxy-1,3-dimethacryloyloxypropane containing a hydroxyl group is more preferred.

[0046] The content of the polyfunctional (meth)acrylate compound in the second agent is not particularly limited, but is, for example, 50 to 99% by mass, and preferably 60 to 95% by mass, relative to 100% by mass of the second agent. When the content of the polyfunctional (meth)acrylate compound in the second agent is 50 to 99% by mass, the adhesiveness of the dental adhesive composition is improved, and the mechanical strength of the cured product of the dental adhesive composition is improved.

[0047] The ratio of the content of di(meth)acrylate compounds having a molecular weight of less than 400 to the content of di(meth)acrylate compounds having a molecular weight of 400 or more in the second part is arbitrary, but is preferably 0.5 to 2, and more preferably 0.8 to 1.4. By setting the ratio of the content of di(meth)acrylate compounds having a molecular weight of less than 400 to the content of di(meth)acrylate compounds having a molecular weight of 400 or more in the second part to 0.5 to 2, the adhesiveness of the dental adhesive composition is improved.

[0048] <Photopolymerization initiator> The photopolymerization initiator in the second agent is not particularly limited, but examples thereof include α-diketone compounds such as camphorquinone, acylphosphine oxide compounds such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethoxybenzoyldiphenylphosphine oxide, 2,6-dimethylbenzoyldiphenylphosphine oxide, and 2,6-dimethoxybenzoyldiphenylphosphine oxide, benzil ketal, diacetyl ketal, benzil dimethyl ketal, benzil diethyl ketal, benzil bis(2-methoxyethyl) ketal, 4,4'-dimethyl(benzyl dimethyl ketal), anthraquinone, 1-chloroanthraquinone, 2-chloroanthraquinone, 1,2-benzanthraquinone, 1-hydroxyanthraquinone, 1-hydroxybenzoyldiphenylphosphine oxide ... Examples of photopolymerization initiators include anthraquinone, 1-methylanthraquinone, 2-ethylanthraquinone, 1-bromoanthraquinone, thioxanthone, 2-isopropylthioxanthone, 2-nitrothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, 2-chloro-7-trifluoromethylthioxanthone, thioxanthone-10,10-dioxide, thioxanthone-10-oxide, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzophenone, bis(4-dimethylaminophenyl)ketone, 4,4'-bis(diethylamino)benzophenone, and compounds containing an azide group. Two or more of these photopolymerization initiators may be used in combination.

[0049] The content of the photopolymerization initiator in the second agent is not particularly limited, but is, for example, 0.01 to 8% by mass, and preferably 3 to 6% by mass, relative to 100% by mass of the second agent. When the content of the photopolymerization initiator in the second agent is 0.01 to 8% by mass, the adhesiveness of the dental adhesive composition is improved, and the storage stability of the dental adhesive composition as a bonding agent is improved.

[0050] <Filler> The second agent may contain a filler. The content of the filler in the second agent is 0 to 50% by mass, and preferably 0.1 to 20% by mass. In other words, when the second agent contains a filler, it does not contain more than 50% by mass of the filler.

[0051] If the filler content in the second part exceeds 50% by mass, operability may be impaired and the adhesiveness may decrease due to a decrease in the amount of polymerizable components. On the other hand, if the filler content in the second part is 50% by mass or less, the dispersibility of the second part improves, and the storage stability of the dental adhesive composition as a bonding agent improves.

[0052] <Other ingredients> The second agent may further contain a tertiary amine and a polymerization inhibitor.

[0053] The tertiary amine in the second agent can function as a polymerization accelerator, just as in the first agent. The tertiary amine in the second agent is not particularly limited, but preferred examples include aromatic tertiary amines such as ethyl 4-dimethylaminobenzoate. When a tertiary amine is contained, the content of the tertiary amine in the second agent is not particularly limited, but is, for example, 0.01 to 5% by mass, and preferably 1 to 4% by mass, relative to 100% by mass of the second agent.

[0054] The polymerization inhibitor in the second part is not particularly limited, and examples thereof include dibutylhydroxytoluene, 2,6-t-butyl-2,4-xylenol, etc. When a polymerization inhibitor is contained, the content of the polymerization inhibitor in the second part is not particularly limited, and is, for example, 0.01 to 3 mass % and preferably 0.1 to 1 mass % relative to 100 mass % of the second part.

[0055] <Excluded ingredients in the second drug> The second agent is substantially free of 2-hydroxyethyl methacrylate (HEMA). If the second agent substantially contains HEMA, the strength of the cured layer of the dental adhesive composition will decrease over time due to water absorption. In contrast, in this embodiment, since the second agent is substantially free of HEMA, it is possible to prevent the strength of the cured layer of the dental adhesive composition from decreasing over time due to water absorption.

[0056] Furthermore, for the same reasons as for 2-hydroxyethyl methacrylate (HEMA), it is preferable that the second agent does not substantially contain monofunctional (meth)acrylate compounds having a hydroxyl group, such as 2,3-dihydroxypropyl methacrylate, and monofunctional (meth)acrylamides, such as N,N-diethylacrylamide.

[0057] It is preferable that the second agent is substantially free of a (meth)acrylate compound having an acid group. If the second agent substantially contains a (meth)acrylate compound having an acid group, deterioration of the photopolymerization initiator may occur depending on the type, and the polymerizability may decrease. In contrast, if the second agent is substantially free of a (meth)acrylate compound having an acid group, the storage stability of the photopolymerization initiator in the second agent is improved, and the decrease in the polymerizability of the dental adhesive composition can be suppressed.

[0058] It is more preferable that the second agent is substantially free of a chemical polymerization initiator. If the second agent contains a chemical polymerization initiator, the storage stability of the second agent as a bonding agent may be reduced. Examples of such chemical polymerization initiators include vanadium compounds such as vanadium acetylacetonate.

[0059] As described above, the dental adhesive composition according to this embodiment is substantially free of 2-hydroxyethyl methacrylate (HEMA) in both the first and second parts, and therefore the strength is less likely to decrease over time in a humid environment. Therefore, according to this embodiment, a dental adhesive composition can be obtained that improves adhesion and the mechanical strength of the cured product.

[0060] <Use of dental composition> The dental adhesive composition according to this embodiment is used by applying the first agent to a target, followed by air blowing, and then applying the second agent to the target. Here, the target may be either a tooth or a restoration (such as a composite resin prosthesis). Air blowing can be performed by a known method, and may be performed immediately after applying the first agent.

[0061] The first agent may be applied in any manner, for example, by applying the first agent to the target by a known method, and the second agent may be applied in any manner, for example, by applying the second agent to the target to which the first agent has been applied by a known method.

[0062] When used in this manner, the dental adhesive composition according to this embodiment can be used in the same manner as conventional two-component dental adhesive compositions, and is therefore easy to handle as a two-component dental adhesive composition.

[0063] <Uses of dental adhesive composition> The dental adhesive composition of this embodiment is not particularly limited in its use, and can be used for various dental materials. Examples of uses of the dental adhesive composition of this embodiment include dental cement, dental adhesive, dental temporary sealing material, dental coating material, dental hard resin, dental cutting resin material, dental temporary restorative material, dental filler, and dentifrice. Among these, the dental adhesive composition is preferably used for dental adhesives. [Example]

[0064] The present invention will be further described below using examples and comparative examples. In the following, "parts" and "%" are by mass unless otherwise specified. Various tests and evaluations were performed according to the following methods.

[0065] <Sample (first agent)> The first agent constituting the two-component dental adhesive composition was prepared according to the formulation shown in Table 1. The first agent formulated in Table 1 had a pH of 1.5.

[0066] [Table 1]

[0067] The specifications of the ingredients indicated by abbreviations or product names in Table 1 are as follows:

[0068] GDMA: 2-hydroxy-1,3-dimethacryloyloxypropane TEGDMA: Triethylene glycol dimethacrylate AEROSIL® R972: Fine particle silica surface-treated with dimethyldichlorosilane (DDS) (manufactured by Nippon Aerosil Co., Ltd.) 4-META: 4-methacryloyl Iruo Trimellitic anhydride MDP: 10-methacryloyloxydecyl dihydrogen phosphate CQ: Camphorquinone EPA: Ethyl 4-dimethylaminobenzoate TPO: 2,4,6-trimethoxybenzoyldiphenylphosphine oxide BHT: Dibutylhydroxytoluene

[0069] <Sample (Second Agent)> The second part of the two-component dental adhesive composition was prepared according to the formulation shown in Table 2.

[0070] [Table 2]

[0071] The specifications of the ingredients indicated by abbreviations or product names in Table 2 are as follows:

[0072] Bis-GMA: Bisphenol A diglycidyl methacrylate BPE-200: Ethoxylated bisphenol A dimethacrylate UDMA: 1,6-bis-[2-methacryloyloxyethoxycarbonylamino]-2,4,4-trimethylhexane GDMA: 2-hydroxy-1,3-dimethacryloyloxypropane TEGDMA: Triethylene glycol dimethacrylate NPG: Neopentyl glycol dimethacrylate HEMA: 2-hydroxyethyl methacrylate MDP: 10-methacryloyloxydecyl dihydrogen phosphate CQ: Camphorquinone EPA: Ethyl 4-dimethylaminobenzoate TPO: 2,4,6-trimethoxybenzoyldiphenylphosphine oxide BHT: Dibutylhydroxytoluene AEROSIL (registered trademark) RX50: Fine particle silica surface-treated with hexamethyldisilazane (manufactured by Nippon Aerosil Co., Ltd.) AEROSIL® R812: Fine particle silica surface-treated with hexamethyldisilazane (manufactured by Nippon Aerosil Co., Ltd.) AEROSIL (registered trademark) RX200: Fine particle silica surface-treated with hexamethyldisilazane (manufactured by Nippon Aerosil Co., Ltd.)

[0073] <Shear adhesive strength> Shear bond strength was measured with reference to an adhesion test in accordance with ISO29022 (2013). A bovine mandibular anterior tooth was embedded in a self-polymerizing resin. Next, the enamel and dentin were exposed using #120-SiC waterproof abrasive paper, and the test surface was then polished using #400-SiC waterproof abrasive paper. A self-etching primer (first agent or first liquid) was applied to the test surface using an applicator and left to stand for 10 seconds. Next, the bond (second agent or second liquid) was applied using an applicator. After the bond was uniformly mixed with low-pressure air, a plastic mold with a Φ2.38 mm hole was placed on the test surface. ListedThe bond was then cured by irradiating the mold with light for 10 seconds using a light irradiator (G-Light Prima II Plus, manufactured by GC Corporation). A composite resin (Clearfil AP-X, manufactured by Kuraray Noritake Dental Co., Ltd.) was filled into the hole and irradiated with light for 20 seconds using a light irradiator. The mold was removed so as not to apply load to the specimen, and the specimen was stored in water at 37°C for 24 hours. The dimensions of the specimen were measured, and then a shear bond test was performed using a universal testing machine (EZ-S, manufactured by Shimadzu Corporation) (crosshead speed: 1 mm / min). The shear bond strength was calculated from the dimensions and the stress value obtained in the shear bond test. Measurements were performed with N=5. The shear bond strength was evaluated for enamel using the following criteria: excellent: 35 MPa or more, good: 25 MPa to less than 35 MPa, and poor: less than 25 MPa. elephant For dentin, the criteria were as follows: excellent: 45 MPa or more, good: 35 MPa or more but less than 45 MPa, and poor: less than 35 MPa. The results are shown in Table 3.

[0074] <Polymerization rate> An OHP sheet and a ring with a diameter of 10 mm and a thickness of 1.0 mm were placed on the slide glass, and the second agent was filled in excess so as not to trap air bubbles inside the ring. Listed The bond was cured by applying light to the front and back surfaces of the bonded specimens for 10 seconds each using a light irradiator (G-Light Prima II Plus, manufactured by GC Corporation). The bonded specimens were analyzed by FT-IR (NICOLET) 5 minutes after preparation. (registered trademark) The peak after polymerization was measured using the ATR method on an FT-IR spectrometer (iS50, manufactured by Thermo Scientific). Similarly, the bond before curing was measured by FT-IR to measure the peak before polymerization. The peaks before and after polymerization were compared, and the polymerization rate was calculated using the following formula. Note that all measurements were carried out with N=5. The polymerization rate was evaluated using the following criteria: excellent: 75% or more, good: 60% to less than 75%, and poor: less than 60%. The results are shown in Table 3.

[0075]

number

[0076] <Bending strength> The bending strength was measured using a bending test in accordance with ISO4049 (2019). A glass plate and an OHP sheet were placed on a metal plate. of The mold was placed in place and filled with the adhesive (second liquid). The specimens were pressed together using an overhead projector sheet and a glass plate. A light irradiator (G-Light Prima II Plus, manufactured by GC Corporation) was used to irradiate the glass plate with nine light sources for 10 seconds each on both sides to cure the adhesive. After 15 minutes in a 37°C thermostatic chamber, the specimens were removed from the mold, deburred using #320 waterproof sandpaper, and stored in water at 37°C for 24 hours and one week. The dimensions of the specimens were measured, and then a three-point bending test was performed using a universal testing machine (AG-IS, manufactured by Shimadzu Corporation) (crosshead speed: 1 mm / min). The three-point bending strength was calculated from the dimensions and the stress values ​​obtained from the three-point bending test. The bending strength was then measured after one day (24 hours) and one week. Each measurement was performed with N=5. The bending strength was evaluated based on the following criteria: excellent: 120 MPa or more, good: 100 MPa or more and less than 120 MPa, and poor: less than 100 MPa. The results are shown in Table 3.

[0077] <Decrease in bending strength> The bending strength reduction rate was calculated from the bending strength after one day and one week obtained in the bending test using the following formula. Note that when the bending strength reduction rate is negative, it indicates that the water absorption of the cured product of the dental adhesive composition was suppressed, and furthermore, the reduction in polymerization was suppressed, which led to the progress of polymerization over time and an increase in bending strength. The results are shown in Table 3.

[0078]

number

[0079] <Vickers hardness> Vickers hardness was measured using a Vickers hardness tester. An OHP sheet and a ring with a diameter of 15 mm and a thickness of 1.5 mm were placed on a glass slide, and the ring was filled with excess glue (second liquid) so that no air bubbles were trapped inside. ListedThe specimens were then pressed together using a glass slide. Using a light irradiator (G-Light Prima II Plus, manufactured by GC Corporation), light was applied to both the front and back surfaces, one at the center and eight at the circumference, for 10 seconds each, to cure the bond. The resulting cured specimens were polished using SiC waterproof abrasive paper, successively using #1200, #2400, and #4000 grits, and then stored in water at 37°C for 24 hours and one week. The Vickers hardness of the resulting specimens was measured using a micro-Vickers tester (HMV-G21D1, manufactured by Shimadzu Corporation) after one day (24 hours) and one week (HV 0.2, holding time 10 seconds, three specimens, N = 5 measurements per specimen). Vickers hardness was evaluated using the following criteria: excellent: 25 HV or greater; good: 20 HV to less than 25 HV; and poor: less than 20 HV. The results are shown in Table 3.

[0080] <Vickers hardness reduction rate> The Vickers hardness decrease rate was calculated from the Vickers hardness after one day and one week obtained by the above Vickers hardness test using the following formula. The results are shown in Table 3.

[0081]

number

[0082] <Water absorption amount> Water absorption was measured using a water absorption test in accordance with ISO 4049 (2019). A transparency sheet and a 15mm diameter, 1.0mm thick ring were placed on a glass slide, and the second liquid adhesive was poured into the ring, ensuring no air bubbles were trapped inside. The transparency sheet was then placed on top and pressed against the glass slide. The adhesive was cured by irradiating the front and back surfaces with light from one central point and eight circumferential points for 20 seconds each using a light irradiator (G-Light Prima II Plus, GC Corporation). The resulting cured specimen was then placed in a desiccator in an incubator set at 37°C. The test was repeated until the mass loss was 0.1g or less within 24 hours, and the volume (V) and weight (m1) of the specimen were determined. The specimen was immersed in distilled water in a sample container and left in an incubator set at 37°C for one week, after which the weight (m2) of the specimen was weighed. Water absorption was calculated using the following formula: Measurements were performed with N=5. The water absorption rating was excellent: 50 μg / mm 3 Less than 50μg / mm 3 More than 60μg / mm 3 Less than 60μg / mm 3 The results were as shown in Table 3.

[0083]

number

[0084] [Table 3]

[0085] From Tables 1 to 3, it can be seen that when the second agents of Examples 1 to 7 were used, all items were excellent or good, and the adhesive compositions exhibited good adhesion while being resistant to loss of strength over time in a humid environment.

[0086] On the other hand, when HEMA was blended into the second agent (Comparative Examples 1 and 2), and when HEMA and MDP were blended (Comparative Example 3), it was found that the bending strength and Vickers hardness decreased after one week of immersion in water.

[0087] Although the embodiments of the present invention have been described above, the present invention is not limited to the specific embodiments, and various modifications and changes are possible within the scope of the invention described in the claims.

Claims

1. A two-component dental adhesive composition comprising a first component and a second component, the first agent contains 5 to 20% by mass of a (meth)acrylate compound having an acid group, 5 to 20% by mass of a (meth)acrylate compound not having an acid group, water, and a water-soluble organic solvent; the (meth)acrylate compound having an acid group is 10-(meth)acryloyloxydecyl dihydrogen phosphate and / or 4-(meth)acryloyloxyethyl trimellitic anhydride, the (meth)acrylate compound having no acid group is 2-hydroxy-1,3-dimethacryloyloxypropane and / or triethylene glycol dimethacrylate, the second agent contains 60 to 95% by mass of a polyfunctional (meth)acrylate compound, a photopolymerization initiator, 2 to 4% by mass of a tertiary amine, and 0 to 50% by mass of a filler; The polyfunctional (meth)acrylate compound is at least one selected from bisphenol A diglycidyl methacrylate, 2-(4-(meth)acryloyloxydiethoxyphenyl)-2-(4-(meth)acryloyloxytriethoxyphenyl)propane, 1,6-bis-[2-methacryloyloxyethoxycarbonylamino]-2,4,4-trimethylhexane, 2-hydroxy-1,3-dimethacryloyloxypropane, triethylene glycol dimethacrylate, and neopentyl glycol dimethacrylate; Both the first agent and the second agent are substantially free of 2-hydroxyethyl methacrylate, The first agent has a pH of 1.5 to 2.0, A dental adhesive composition, wherein the cured product of the dental adhesive composition has a polymerization rate of 75 to 79.2%.

2. 2. The dental adhesive composition according to claim 1, wherein the polyfunctional (meth)acrylate compound in the second agent contains a di(meth)acrylate compound having a molecular weight of 400 or more and a di(meth)acrylate compound having a molecular weight of less than 400.

3. 3. The dental adhesive composition according to claim 2, wherein the ratio of the content of the di(meth)acrylate compound having a molecular weight of less than 400 to the content of the di(meth)acrylate compound having a molecular weight of 400 or more in the second part is 0.5 to 2.

4. The dental adhesive composition according to any one of claims 2 to 3, wherein the di(meth)acrylate compound having a molecular weight of 400 or more in the second agent includes an aromatic di(meth)acrylate compound and an aliphatic di(meth)acrylate compound.

5. The dental adhesive composition according to any one of claims 2 to 4, wherein the di(meth)acrylate compound having a molecular weight of less than 400 in the second agent is a di(meth)acrylate compound containing a hydroxyl group.

6. 6. The dental adhesive composition according to claim 1, wherein the second agent is substantially free of a (meth)acrylate compound having an acid group.

7. The dental adhesive composition according to any one of claims 1 to 6, which is used by applying the first agent to an object, blowing air therethrough, and then applying the second agent to the object.

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