Organosilicon compound and dental composition containing said compound

Abstract

The present invention provides a dental composition that shows improved adhesion to both a dental restorative material such as a porcelain and dentin and that is suitable for suppressing changes in properties during storage. The present invention pertains to a dental composition that contains an organosilicon compound (A) represented by general formula (1).　(1): Z-Xm-Y-SiR1 nR2 (3-n) (In the formula: Z represents a (meth)acryloyloxy group, a (meth)acrylamido group, a mercapto group or an epoxy group; X represents a divalent organic group in which the ratio of the total number of carbon atoms to the total number of oxygen atoms (C / O) is 1-3; Y represents a divalent hydrocarbon group having 1-30 carbon atoms; R1 represents a group selected from the group consisting of an alkyl group, an aryl group and an aralkyl group; R2 represents a hydroxyl group or a hydrolyzable group; m represents an integer of 1-8; and n represents 0, 1 or 2. Two or more R1s, R2s and Xs, if present, may be either the same or different.)

Description

[Technical Field]

[0001] The present invention relates to novel organosilicon compounds and dental compositions containing said compounds. [Background technology]

[0002] In recent years, as dental restorations have come to require not only functionality but also aesthetics after restoration, composite resins and ceramic materials such as zirconia, alumina, lithium disilicate glass, and porcelain have begun to be used as dental restorative materials for crown restorations in addition to the metals that have traditionally been used. Dental primers and dental adhesives are used to bond such dental restorative materials to the substrate.

[0003] As examples of dental primers and dental adhesives, for example, Patent Document 1 discloses a specific one-component dental primer containing a silane coupling agent, an acidic group-containing polymerizable monomer, and a volatile organic solvent. Patent Document 2 discloses a one-component adhesive composition containing a specific silane coupling agent, an acidic group-containing polymerizable monomer, a primary alcohol, and water, with a water content of 0.005 to 0.5% by mass.

[0004] In recent years, dental compositions have become more versatile, and there has been a demand for one-component dental compositions that can be used with a single component on many adherends, including tooth structure. However, because the properties of dental restorative materials such as porcelain and tooth structure differ significantly, it is difficult to impart high adhesion to both of them, and compositions such as those described in Patent Documents 1 and 2 above have room for further improvement in terms of adhesion. While adding water is considered as a way to improve adhesion to tooth structure, simply adding water significantly reduces the storage stability of the silane coupling agent, thereby reducing adhesion to dental restorative materials.

[0005] On the other hand, Patent Document 3 discloses a dental composition containing a specific silane coupling agent, an acidic group-containing polymerizable monomer, and water, and having a water content of 1.0 to 50 mass %, as an example of a one-component dental composition that can be used in one component for a wide variety of adherends, including not only dental restorative materials but also tooth structures, which is a technology aimed at solving the above-mentioned problems. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2008 / 053990 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-1624 [Patent Document 3] International Publication No. 2019 / 082855 Summary of the Invention [Problem to be solved by the invention]

[0007] However, according to the studies of the present inventors, the dental composition described in Patent Document 3 certainly exhibits high adhesion to both dental restorative materials such as porcelain and tooth structure, but it has been confirmed that, apart from adhesion, the viscosity of the dental composition increases and the thixotropy of the dental composition becomes stronger during long-term storage, and the operability immediately after production is not maintained even after long-term storage, making it difficult to extract the dental composition from a container filled with it and difficult to form a coating surface on an adherend, and it has been newly confirmed that there is room for further improvement in terms of operability. In other words, it has been newly confirmed that there is room for further improvement in terms of property stability during storage.

[0008] Therefore, an object of the present invention is to provide a dental composition that exhibits improved adhesion to both dental restorative materials such as porcelain and tooth structure, and is suitable for suppressing changes in properties during storage. [Means for solving the problem]

[0009] As a result of extensive research to solve the above-mentioned problems, the inventors have discovered that a dental composition containing an organosilicon compound having a specific structure exhibits improved adhesion to both dental restorative materials such as porcelain and tooth structure, and that a dental composition suitable for suppressing changes in properties during storage can be obtained.Based on this finding, further research has led to the completion of the present invention.

[0010] That is, the present invention includes the following inventions. [1] A dental composition comprising an organosilicon compound (A) represented by the following general formula (1): Z-X m -Y-SiR 1 n R 2 (3-n) (1) (In the formula, Z represents a (meth)acryloyloxy group, a (meth)acrylamide group, a mercapto group, or an epoxy group; X represents a divalent organic group having a ratio (C / O) of the total number of carbon atoms to the total number of oxygen atoms of 1 to 3; Y represents a divalent hydrocarbon group having 1 to 30 carbon atoms; and R 1 represents a group selected from the group consisting of an alkyl group, an aryl group, and an aralkyl group; R 2 represents a hydroxyl group or a hydrolyzable group, m represents an integer of 1 to 8, and n represents 0, 1, or 2. 1 , R 2 When there are a plurality of X's, they may be the same or different. [2] The dental composition according to [1], wherein X has 1 to 3 carbon atoms. [3] The dental composition according to [1] or [2], wherein X is a group represented by the following formula (2), (3), or (4): -CH2O- (2) -CH2CH2O- (3) —CH2CH2CH2O— (4) [4] The dental composition according to any one of [1] to [3], wherein m is an integer of 1 to 4. [5] The dental composition according to any one of [1] to [4], wherein n is 1 or 2. [6] The dental composition according to any one of [1] to [5], wherein Z is a (meth)acryloyloxy group. [7]R 2 The dental composition according to any one of [1] to [6], wherein is an alkoxy group having 1 to 5 carbon atoms. [8] The dental composition according to any one of [1] to [7], wherein the content of the organosilicon compound (A) is 0.1 to 50 mass %. [9] The dental composition according to any one of [1] to [8], further comprising a monomer (B) having an acidic group.

[10] The dental composition according to [9], wherein the monomer (B) having an acidic group includes a monomer having a phosphate group.

[11] The dental composition according to any one of [1] to

[10] , further comprising water (C).

[12] The dental composition according to any one of [1] to

[11] , further comprising a monomer (D) having no acidic group.

[13] The dental composition according to

[12] , wherein the monomer (D) having no acidic group includes a hydrophilic monomer (D-2) having no acidic group.

[14] The dental composition according to

[13] , wherein the hydrophilic monomer (D-2) having no acidic group is contained in an amount of 8 to 90 mass % based on the mass of all monomers contained in the dental composition.

[15] A dental adhesive comprising the dental composition according to any one of [1] to

[14] .

[16] An organosilicon compound (A) represented by the following general formula (1): Z-X m -Y-SiR 1 n R 2 (3-n) (1) (In the formula, Z represents a (meth)acryloyloxy group, a (meth)acrylamide group, a mercapto group, or an epoxy group; X represents a divalent organic group having a ratio (C / O) of the total number of carbon atoms to the total number of oxygen atoms of 1 to 3; Y represents a divalent hydrocarbon group having 1 to 30 carbon atoms; and R 1 represents a group selected from the group consisting of an alkyl group, an aryl group, and an aralkyl group; R 2 represents a hydroxyl group or a hydrolyzable group, m represents an integer of 1 to 8, and n represents 0, 1, or 2. 1 , R 2When there are a plurality of X's, they may be the same or different.

[17] The organosilicon compound (A) according to

[16] , wherein X has 1 to 3 carbon atoms.

[18] The organosilicon compound (A) according to

[16] or

[17] , wherein X is a group represented by the following formula (2), (3), or (4): -CH2O- (2) -CH2CH2O- (3) —CH2CH2CH2O— (4) [Effects of the Invention]

[0011] According to the present invention, a dental composition is provided that exhibits improved adhesion to both dental restorative materials such as porcelain and tooth structure and is suitable for suppressing changes in properties during storage. Furthermore, according to the present invention, a dental composition is provided that exhibits improved adhesion to both dental restorative materials such as porcelain and tooth structure even after long-term storage and has excellent storage stability. Furthermore, according to the present invention, when the dental composition is filled into a container, even after long-term storage, the operability immediately after production is maintained, and the dental composition is easy to take from the container filled with the dental composition, resulting in excellent operability. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention will be described in detail below. In this specification, the upper and lower limits of the numerical ranges (contents of each component, values ​​calculated from each component, physical properties, etc.) can be combined as appropriate.

[0013] The dental composition of the present invention is a dental composition containing an organosilicon compound (A) represented by the following general formula (1). Z-X m -Y-SiR 1 n R 2 (3-n) (1) (In the formula, Z represents a (meth)acryloyloxy group, a (meth)acrylamide group, a mercapto group, or an epoxy group; X represents a divalent organic group having a ratio (C / O) of the total number of carbon atoms to the total number of oxygen atoms of 1 to 3; Y represents a divalent hydrocarbon group having 1 to 30 carbon atoms; and R 1 represents a group selected from the group consisting of an alkyl group, an aryl group, and an aralkyl group; R 2 represents a hydroxyl group or a hydrolyzable group, m represents an integer of 1 to 8, and n represents an integer of 0, 1, or 2. However, if there are multiple R 1 , R 2 may be the same or different, and a plurality of X's may be the same or different.

[0014] The dental composition of the present invention contains the organosilicon compound (A) represented by general formula (1), and thus exhibits high adhesion to both dental restorative materials such as porcelain and tooth structure, and exhibits little change in properties during storage.

[0015] The reasons why the present invention provides such excellent effects are not entirely clear, but are presumed to be as follows: Most of the spacers in silane coupling agents conventionally used in dental applications are alkyl groups, resulting in relatively high hydrophobicity. Such silane coupling agents have low compatibility with water and hydrophilic polymerizable monomers, which are included in dental compositions such as dental adhesives and dental primers to improve adhesion to tooth tissue. While phase separation may not occur, this increases the likelihood of contact between silane coupling agents in the system. As a result, self-condensation reactions between silane coupling agents are more likely to occur, resulting in increased viscosity and thixotropy, leading to significant changes in properties during storage. On the other hand, the organosilicon compound (A) of the present invention is relatively hydrophilic due to the presence of an oxygen atom, such as an ether bond, in X, the spacer between X and Y. Therefore, it is believed that the compound has superior compatibility with water and hydrophilic polymerizable monomers compared to silane coupling agents used in conventional dental compositions. As a result, the probability of contact between the organosilicon compounds (A) within the system is reduced, making it less likely that self-condensation reactions will occur between the silane coupling agents (between the organosilicon compounds (A)), and reducing changes in properties during storage.

[0016] Organosilicon compounds (A) The organosilicon compound (A) of the present invention is represented by the following general formula (1). Z-X m -Y-SiR 1 n R 2 (3-n) (1) (In the formula, Z represents a (meth)acryloyloxy group, a (meth)acrylamide group, a mercapto group, or an epoxy group; X represents a divalent organic group having a ratio (C / O) of the total number of carbon atoms to the total number of oxygen atoms of 1 to 3; Y represents a divalent hydrocarbon group having 1 to 30 carbon atoms; and R 1 represents a group selected from the group consisting of an alkyl group, an aryl group, and an aralkyl group; R 2 represents a hydroxyl group or a hydrolyzable group, m represents an integer of 1 to 8, and n represents 0, 1, or 2. 1 , R 2When there are a plurality of X's, they may be the same or different.

[0017] Z represents a (meth)acryloyloxy group, a (meth)acrylamide group, a mercapto group, or an epoxy group. Among these, a (meth)acryloyloxy group or a (meth)acrylamide group is preferred, and a (meth)acryloyloxy group is more preferred, since this further improves adhesion to both the dental restorative material and tooth structure.

[0018] Y represents a divalent hydrocarbon group having 1 to 30 carbon atoms. As the divalent hydrocarbon group, from the viewpoint of stable properties, it is preferable that it has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, still more preferably 1 to 10 carbon atoms, and particularly preferably 1 to 5 carbon atoms. The divalent hydrocarbon group may have a substituent. Examples of the substituent include a linear or branched alkyl group having 1 to 6 carbon atoms, a halogen atom, and the like. The number of substituents is not particularly limited, and may be 1 to 10, 1 to 6, or 1 to 3. An example of an embodiment is an organosilicon compound (A) in which Y is an unsubstituted divalent hydrocarbon group.

[0019] X represents a divalent organic group having a ratio (C / O) of the total number of carbon atoms to the total number of oxygen atoms of 1 to 3. As described above, the organosilicon compound (A) of the present invention has the property of being relatively hydrophilic and having excellent compatibility with water and hydrophilic polymerizable monomers due to the presence of an oxygen atom, such as an ether bond, in the spacer, in X. The divalent organic group represented by X is not particularly limited as long as it contains an oxygen atom, such as an ether bond, and has a ratio (C / O) of 1 to 3 of the total number of carbon atoms to the total number of oxygen atoms, but it is preferable for the main chain to contain an ether bond. C / O is preferably 1 or 2, as this provides a dental composition with a better balance between the stability of properties and adhesiveness. The number of carbon atoms in X is preferably 1 to 3, as this provides a dental composition with a more stable property.

[0020] X is preferably a group represented by the following formula (2), (3), or (4), and formula (3) is more preferred because it provides a dental composition with a better balance between property stability and adhesiveness. -CH2O- (2) -CH2CH2O- (3) —CH2CH2CH2O— (4)

[0021] m represents an integer of 1 to 8, and is preferably an integer of 1 to 4, more preferably 1 or 2, in view of stabilizing the properties of the dental composition. Multiple Xs may be the same or different.

[0022] Examples of the divalent hydrocarbon group represented by Y include an alkenylene group and an alkylene group, with an alkylene group being preferred. The alkenylene group having 2 to 30 carbon atoms may be either linear or branched, and examples thereof include a vinylene group, a propenylene group, a butenylene group, a pentenylene group, a hexenylene group, an octenylene group, a nonenylene group, and a decenylene group. The alkylene group having 1 to 30 carbon atoms may be either linear or branched, and examples thereof include a methylene group, an ethylene group, an n-propylene group, an isopropylene group, an n-butylene group, and an n-pentylene group, with an ethylene group and an n-propylene group being preferred, and an ethylene group being more preferred.

[0023] R 1 There is no particular limitation on the type of alkyl group represented by the formula (I), and examples thereof include alkyl groups having 1 to 5 carbon atoms, more specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and an n-pentyl group.

[0024] R 1 There is no particular limitation on the type of aryl group represented by the formula, and examples thereof include aryl groups having 6 to 10 carbon atoms, more specifically, examples thereof include a phenyl group and a naphthyl group.

[0025] R 1There is no particular limitation on the type of aralkyl group represented by the formula: and examples thereof include aralkyl groups having 7 to 12 carbon atoms, and more specific examples thereof include a benzyl group.

[0026] Among these, R is the most popular because it has better adhesion to dental restorative materials. 1 is preferably an alkyl group, more preferably an alkyl group having 1 to 5 carbon atoms, and even more preferably a methyl group.

[0027] R 2 The hydrolyzable group represented by the formula (I) can be a group that can form a silanol group together with the silicon atom to which it is bonded by hydrolysis, and examples thereof include an alkoxy group, an acyloxy group, a siloxy group, and a halogen atom.

[0028] The type of the alkoxy group is not particularly limited and may be either linear or branched. Examples of the alkoxy group include alkoxy groups having 1 to 5 carbon atoms, and more specific examples include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, and an n-pentyloxy group.

[0029] The type of the acyloxy group is not particularly limited and may be either linear or branched. Examples of the acyloxy group include acyloxy groups having 1 to 5 carbon atoms. More specific examples include a formyloxy group, an acetoxy group, an n-propionyloxy group, an isopropionyloxy group, an n-butanoyloxy group, and an n-pentanoyloxy group.

[0030] The type of the siloxy group is not particularly limited, and examples thereof include a trimethylsiloxy group.

[0031] The type of the halogen atom is not particularly limited, and examples thereof include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0032] Among these, R is the most popular because it has better adhesion to dental restorative materials.2 is preferably an alkoxy group, more preferably an alkoxy group having 1 to 5 carbon atoms, and further preferably a methoxy group or an ethoxy group.

[0033] n represents 0, 1 or 2, and the self-condensation reaction between the organosilicon compounds (A) is unlikely to occur, and the steric hindrance of the condensation product of the organosilicon compounds (A) is reduced, and the R originally possessed by the organosilicon compounds (A) is reduced. 2 Since this makes it easier for R to bond with the dental restorative material, n is preferably 1 or 2. When n is 0 or 1, if there are multiple R 2 may be the same or different, and when n is 2, a plurality of R 1 may be the same or different from each other.

[0034] Specific examples of the organosilicon compound (A) of the present invention are shown below.

[0035] [ka] [ka] [ka] [ka]

[0036] [ka] [ka] [ka] [ka]

[0037]

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[0038]

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[0039]

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[0040]

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[0041]

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[0042]

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[0043]

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[0044]

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[0045] [ka] [ka] [ka] [ka]

[0046] [ka] [ka] [ka] [ka]

[0047] [ka]

[0048] Furthermore, it may be a precursor that becomes the organosilicon compound represented by formula (1) after hydrolysis. The organosilicon compound (A) may be used alone or in combination of two or more kinds.

[0049] The content of the organosilicon compound (A) in the dental composition of the present invention is preferably 0.1% by mass or more, more preferably 1% by mass or more, and even more preferably 3% by mass or more, because this improves adhesion to both dental restorative materials and tooth structure. The content of the organosilicon compound (A) is preferably 50% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, and particularly preferably 15% by mass or less. Although the organosilicon compound (A) may undergo hydrolysis and / or condensation in the dental composition, the above content refers to the content assuming that the organosilicon compound (A) has not undergone hydrolysis and / or condensation.

[0050] Monomers with acidic groups (B) The dental composition of the present invention preferably further contains a monomer (B) having an acidic group. The monomer (B) having an acidic group penetrates and bonds to the tooth while demineralizing the tooth, thereby improving adhesion to the tooth. The monomer (B) having an acidic group may be any monomer having at least one acidic group such as a phosphate group, phosphonate group, pyrophosphate group, carboxylic acid group, or sulfonic acid group, and at least one polymerizable group such as an acryloyl group, methacryloyl group, acrylamide group, or methacrylamide group. From the viewpoint of adhesion to enamel, the monomer (B) having an acidic group is preferably a monofunctional monomer having one of an acryloyl group, methacryloyl group, acrylamide group, or methacrylamide group. Specific examples include the following.

[0051] Examples of the monomer having a phosphate group include 2-(meth)acryloyloxyethyl dihydrogen phosphate, 3-(meth)acryloyloxypropyl dihydrogen phosphate, 4-(meth)acryloyloxybutyl dihydrogen phosphate, 5-(meth)acryloyloxypentyl dihydrogen phosphate, 6-(meth)acryloyloxyhexyl dihydrogen phosphate, 7-(meth)acryloyloxyheptyl dihydrogen phosphate, 8-(meth)acryloyloxyoctyl dihydrogen phosphate, 9-(meth)acryloyloxynonyl dihydrogen phosphate, 10-(meth)acryloyloxydecyl dihydrogen phosphate, and 11-(meth)acryloyloxyundecyl dihydrogen phosphate. monofunctional (meth)acrylate compounds containing a phosphate group, such as 2-(meth)acryloyloxyethylphenylhydrogenphosphate, 12-(meth)acryloyloxydodecyldihydrogenphosphate, 16-(meth)acryloyloxyhexadecyldihydrogenphosphate, 20-(meth)acryloyloxyeicosyldihydrogenphosphate, 2-(meth)acryloyloxyethylphenylhydrogenphosphate, 2-(meth)acryloyloxyethyl-2-bromoethylhydrogenphosphate, 2-(meth)acryloyloxyethyl-(4-methoxyphenyl)hydrogenphosphate, and 2-(meth)acryloyloxypropyl-(4-methoxyphenyl)hydrogenphosphate, as well as acid chlorides, alkali metal salts, and ammonium salts thereof;Examples of suitable difunctional (meth)acrylate compounds containing a phosphate group include bis[2-(meth)acryloyloxyethyl]hydrogenphosphate, bis[4-(meth)acryloyloxybutyl]hydrogenphosphate, bis[6-(meth)acryloyloxyhexyl]hydrogenphosphate, bis[8-(meth)acryloyloxyoctyl]hydrogenphosphate, bis[9-(meth)acryloyloxynonyl]hydrogenphosphate, bis[10-(meth)acryloyloxydecyl]hydrogenphosphate, and 1,3-di(meth)acryloyloxypropyl dihydrogenphosphate, as well as acid chlorides, alkali metal salts, and ammonium salts thereof;

[0052] Examples of the monomer having a phosphonic acid group include 2-(meth)acryloyloxyethyl phenyl phosphonate, 5-(meth)acryloyloxypentyl-3-phosphonopropionate, 6-(meth)acryloyloxyhexyl-3-phosphonopropionate, 10-(meth)acryloyloxydecyl-3-phosphonopropionate, 6-(meth)acryloyloxyhexyl phosphonoacetate, 10-(meth)acryloyloxydecyl phosphonoacetate, and acid chlorides, alkali metal salts, and ammonium salts thereof.

[0053] Examples of monomers having a pyrophosphate group include bis[2-(meth)acryloyloxyethyl] pyrophosphate, bis[4-(meth)acryloyloxybutyl] pyrophosphate, bis[6-(meth)acryloyloxyhexyl] pyrophosphate, bis[8-(meth)acryloyloxyoctyl] pyrophosphate, bis[10-(meth)acryloyloxydecyl] pyrophosphate, and acid chlorides, alkali metal salts, and ammonium salts thereof.

[0054] Examples of the monomer having a carboxylic acid group include (meth)acrylic acid, 4-(meth)acryloyloxyethoxycarbonylphthalic acid, 4-(meth)acryloyloxyethyltrimellitic acid, 4-(meth)acryloyloxybutyloxycarbonylphthalic acid, 4-(meth)acryloyloxyhexyloxycarbonylphthalic acid, 4-(meth)acryloyloxyoctyloxycarbonylphthalic acid, 4-(meth)acryloyloxydecyloxycarbonylphthalic acid, 5-(meth)acryloylaminopentylcarboxylic acid, and acid anhydrides, acid chlorides, alkali metal salts, and ammonium salts thereof.

[0055] Examples of the monomer having a sulfonic acid group include 2-(meth)acrylamido-2-methylpropanesulfonic acid, 2-sulfoethyl(meth)acrylate, and acid chlorides, alkali metal salts, and ammonium salts thereof.

[0056] As the monomer (B) having an acidic group, from the viewpoint of exhibiting superior adhesiveness to tooth structure, a monomer having a phosphate group or a monomer having a pyrophosphate group is preferred, a monomer having a phosphate group is more preferred, and a monofunctional monomer having a phosphate group is even more preferred. Among them, a (meth)acrylate-based monofunctional monomer having a phosphate group and an alkyl or alkylene group having 6 to 20 carbon atoms as the main chain in the molecule is preferred, and a (meth)acrylate-based monofunctional monomer having a phosphate group and an alkylene group having 8 to 12 carbon atoms as the main chain in the molecule, such as 10-methacryloyloxydecyl dihydrogen phosphate, is more preferred. The monomer (B) having an acidic group may be used alone or in combination of two or more types.

[0057] The content of the acidic group-containing monomer (B) in the dental composition of the present invention is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 3% by mass or more, based on the mass of all monomers contained in the dental composition, in order to further improve adhesion to both dental restorative materials and tooth structure. Furthermore, the content of the acidic group-containing monomer (B) is preferably 50% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less. In this specification, typical examples of "total monomers contained in the dental composition" include all radically polymerizable monomers, such as monomers having a (meth)acryloyl group, contained in the dental composition that do not fall under the category of organosilicon compound (A).

[0058] ·Water (C) The dental composition of the present invention preferably further contains water (C). By including water (C), the decalcifying action of the monomer (B) having an acidic group can be promoted. The water used to prepare the dental composition of the present invention is preferably distilled water or ion-exchanged water, from the viewpoint of avoiding the introduction of impurities that adversely affect adhesion.

[0059] The content of water (C) in the dental composition of the present invention is preferably 1.0% by mass or more, more preferably 5.0% by mass or more, and even more preferably 8.0% by mass or more, since the dental composition exhibits high adhesiveness to both dental restorative materials such as porcelain and tooth structure. Moreover, since an excessively high content of water (C) reduces adhesiveness, the content of water (C) is preferably 50% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less.

[0060] Monomers without acidic groups (D) From the viewpoint of adhesiveness, the dental composition of the present invention preferably further contains a monomer (D) that does not have an acidic group. As the monomer (D) that does not have an acidic group, a known monomer that does not have an acidic group can be used, such as a hydrophobic monomer (D-1) that does not have an acidic group or a hydrophilic monomer (D-2) that does not have an acidic group. The monomer (D) that does not have an acidic group may be used alone or in combination of two or more types. For example, a hydrophobic monomer (D-1) that does not have an acidic group and a hydrophilic monomer (D-2) that does not have an acidic group may be used in combination.

[0061] (i) Hydrophobic Monomer (D-1) Having No Acidic Group The dental composition of the present invention contains a hydrophobic monomer (D-1) having no acidic group, which can improve the mechanical strength and handleability of the cured product (the product obtained by curing the dental composition). The hydrophobic monomer (D-1) having no acidic group is preferably a radically polymerizable monomer having a polymerizable group but no acidic group. The polymerizable group is preferably a (meth)acryloyl group or a (meth)acrylamide group, because radical polymerization is easy. The hydrophobic monomer (D-1) having no acidic group can be one having a solubility in water at 25°C of less than 10% by mass, and examples of such monomers include crosslinkable monomers such as monofunctional monomers, aromatic bifunctional monomers, aliphatic bifunctional monomers, and trifunctional or higher functional monomers.

[0062] Examples of monofunctional monomers include 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, octafluoropentyl (meth)acrylate, m-phenoxybenzyl (meth)acrylate, biphenylmethyl (meth)acrylate, O-phenylphenolethyl (meth)acrylate, and O-phenyl(EO)2 (meth)acrylate.

[0063] Examples of aromatic bifunctional monomers include 2,2-bis((meth)acryloyloxyphenyl)propane, 2,2-bis[4-(3-(meth)acryloyloxy-2-hydroxypropoxy)phenyl]propane, 2,2-bis(4-(meth)acryloyloxyethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxypolyethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxydiethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxytriethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxytetraethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxypentaethoxyphenyl)propane, 2-(4-(meth)acryloyloxydipropoxyphenyl)propane, 2-(4-(meth)acryloyloxydiethoxyphenyl)-2-(4-(meth)acryloyloxyethoxyphenyl)propane, 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, 2,2-bis(4-(meth)acryloyloxyisopropoxyphenyl)propane, and the like. Among these, 2,2-bis[4-(3-methacryloyloxy-2-hydroxypropoxy)phenyl]propane (commonly known as "Bis-GMA"), 2,2-bis(4-(meth)acryloyloxyethoxyphenyl)propane, 2,2-bis(4-methacryloyloxypolyethoxyphenyl)propane (average number of moles of ethoxy groups added: 2.6, commonly known as "D-2.6E"), 2,2-bis(4-(meth)acryloyloxydiethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxydiethoxyphenyl)propane, Preferred are 2,2-bis[4-(3-methacryloyloxy-2-hydroxypropoxy)phenyl]propane (Bis-GMA) and 2,2-bis(4-methacryloyloxypolyethoxyphenyl)propane (average number of moles of ethoxy groups added: 2.6, commonly known as "D-2.6E"), among which 2,2-bis[4-(3-methacryloyloxy-2-hydroxypropoxy)phenyl]propane (Bis-GMA) and 2,2-bis(4-methacryloyloxypolyethoxyphenyl)propane (average number of moles of ethoxy groups added: 2.6, commonly known as "D-2.6E").

[0064] Examples of the aliphatic difunctional monomer include glycerol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and 1,10-decamethylol dimethacrylate. Examples of suitable acrylamides include methyl acrylate, methyl meth ... Among these, glycerol di(meth)acrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate (commonly known as "3G"), neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,2-bis(3-methacryloyloxy-2-hydroxypropoxy)ethane, 2,2,4-trimethylhexamethylenebis(2-carbamoyloxyethyl)dimethacrylate (commonly known as "UDMA"), N-methacryloyloxyethyl acrylamide (commonly known as "MAEA"), and N-methacryloyloxypropyl acrylamide are preferred.

[0065] Examples of trifunctional or higher functional monomers include trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, trimethylolmethane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, N,N-(2,2,4-trimethylhexamethylene)bis[2-(aminocarboxy)propane-1,3-diol]tetra(meth)acrylate, and 1,7-diacryloyloxy-2,2,6,6-tetra(meth)acryloyloxymethyl-4-oxaheptane. Of these, N,N-(2,2,4-trimethylhexamethylene)bis[2-(aminocarboxy)propane-1,3-diol]tetramethacrylate is preferred.

[0066] Among the above-mentioned hydrophobic monomers (D-1) having no acidic group, aromatic bifunctional monomers and aliphatic bifunctional monomers are preferred from the viewpoint of the mechanical strength and handling of the cured product, and Bis-GMA, D-2.6E, 3G, UDMA, and MAEA are more preferred from the viewpoint of adhesive strength and the mechanical strength of the cured product, and Bis-GMA, 3G, UDMA, and MAEA are even more preferred. The hydrophobic monomers (D-1) having no acidic group may be used alone or in combination of two or more.

[0067] The content of the hydrophobic monomer (D-1) having no acidic group in the dental composition of the present invention is preferably 9% by mass or more, more preferably 15% by mass or more, even more preferably 20% by mass or more, and particularly preferably 25% by mass or more, based on the mass of all monomers contained in the dental composition, from the viewpoints of the mechanical strength and handleability of the cured product (a cured product obtained by curing the dental composition). Moreover, the content of the hydrophobic monomer (D-1) having no acidic group is preferably 90% by mass or less, more preferably 80% by mass or less, even more preferably 75% by mass or less, and particularly preferably 70% by mass or less.

[0068] (ii) Hydrophilic Monomer (D-2) Having No Acidic Group The dental composition of the present invention contains a hydrophilic monomer (D-2) that does not have an acidic group, which not only improves adhesion to tooth tissue but also further suppresses the self-condensation reaction of the organosilicon compound (A) in the dental composition, thereby minimizing changes in the properties of the dental composition during storage. The hydrophilic monomer (D-2) that does not have an acidic group is preferably a radically polymerizable monomer that does not have an acidic group but has a polymerizable group. The polymerizable group is preferably a (meth)acryloyl group or a (meth)acrylamide group, as these groups are easily radically polymerized. The hydrophilic monomer (D-2) that does not have an acidic group can be one that has a solubility in water of 10% by mass or more at 25°C, preferably a solubility of 30% by mass or more, and more preferably one that can be dissolved in water at any ratio at 25°C.

[0069] The hydrophilic monomer (D-2) not having an acidic group is preferably one having a hydrophilic group such as a hydroxyl group, an oxymethylene group, an oxyethylene group, an oxypropylene group, or an amide group. Examples thereof include (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 1,3-dihydroxypropyl (meth)acrylate, 2,3-dihydroxypropyl (meth)acrylate, 2-trimethylammoniumethyl (meth)acrylchloride, and polyethylene glycol di(meth)acrylate (having 9 or more oxyethylene groups); N-methylol (meth)acrylamide, N-hydroxyethyl (meth)acrylamide, N-methoxymethyl (meth)acrylamide, N-ethoxymethyl (meth)acrylamide, diacetone (meth)acrylamide, 4-(meth)acryloylmorpholine, and monofunctional (meth)acrylamides such as disubstituted (meth)acrylamides represented by the following general formula (6):

[0070] [ka]

[0071] In the general formula (6), R 3 and R 4 are each independently a linear or branched alkyl group having 1 to 3 carbon atoms which may have a substituent, and R 5 is a hydrogen atom or a methyl group.

[0072] R 3 and R 4 Examples of the alkyl group having 1 to 3 carbon atoms represented by the following formula include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group, and examples of the substituents that these groups may have include a hydroxyl group.

[0073] Examples of disubstituted (meth)acrylamides represented by the general formula (6) include N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, and N,N-di(hydroxyethyl)(meth)acrylamide. From the viewpoint of storage stability, N,N-dimethylacrylamide and N,N-diethylacrylamide are preferred, and N,N-diethylacrylamide is more preferred.

[0074] Among the above-mentioned hydrophilic monomers (D-2) having no acidic group, from the viewpoint of adhesion to tooth structure, 2-hydroxyethyl (meth)acrylate, 2,3-dihydroxypropyl (meth)acrylate, and monofunctional (meth)acrylamides are preferred, 2-hydroxyethyl (meth)acrylate, 2,3-dihydroxypropyl (meth)acrylate, diacetone (meth)acrylamide, and disubstituted (meth)acrylamides represented by the above-mentioned general formula (6) are more preferred, 2-hydroxyethyl (meth)acrylate and disubstituted (meth)acrylamides represented by the above-mentioned general formula (6) are even more preferred, and 2-hydroxyethyl methacrylate and N,N-diethylacrylamide are particularly preferred. The hydrophilic monomers (D-2) having no acidic group may be used alone or in combination of two or more.

[0075] The content of the hydrophilic monomer (D-2) having no acidic group in the dental composition of the present invention is preferably 8% by mass or more, more preferably 10% by mass or more, and even more preferably 12% by mass or more, based on the mass of all monomers contained in the dental composition, from the viewpoints of adhesion to tooth tissue and minimizing changes in properties during storage, etc. The content of the hydrophilic monomer (D-2) having no acidic group is preferably 90% by mass or less, more preferably 80% by mass or less, even more preferably 70% by mass or less, and particularly preferably 60% by mass or less.

[0076] The total content of all monomers contained in the dental composition of the present invention, including the monomer (B) having an acidic group and the monomer (D) not having an acidic group, is preferably 20% by mass or more, more preferably 35% by mass or more, because this further improves adhesion to both dental restorative materials and tooth structure. The total content of all monomers is preferably 90% by mass or less, more preferably 80% by mass or less.

[0077] Polymerization initiator (E) From the viewpoint of adhesiveness, the dental composition of the present invention preferably further contains a polymerization initiator (E). Known polymerization initiators can be used as the polymerization initiator (E), such as a photopolymerization initiator (E-1) or a chemical polymerization initiator (E-2). The polymerization initiator (E) may be used alone or in combination of two or more types, such as a photopolymerization initiator (E-1) and a chemical polymerization initiator (E-2).

[0078] (i) Photopolymerization initiator (E-1) Examples of the photopolymerization initiator (E-1) include (bis)acylphosphine oxides (including salts), thioxanthones (including salts such as quaternary ammonium salts), ketals, α-diketones, coumarins, anthraquinones, benzoin alkyl ether compounds, and α-aminoketone compounds.

[0079] Among the (bis)acylphosphine oxides, examples of the acylphosphine oxides include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylmethoxyphenylphosphine oxide, 2,4,6-trimethylbenzoylethoxyphenylphosphine oxide, 2,3,5,6-tetramethylbenzoyldiphenylphosphine oxide, and benzoyldi(2,6-dimethylphenyl)phosphonate.

[0080] Of the (bis)acylphosphine oxides, examples of the bisacylphosphine oxides include bis(2,6-dichlorobenzoyl)phenylphosphine oxide, bis(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis(2,6-dichlorobenzoyl)-1-naphthylphosphine oxide, bis(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and bis(2,3,6-trimethylbenzoyl)-2,4,4-trimethylpentylphosphine oxide.

[0081] The acylphosphine oxides may be water-soluble acylphosphine oxides. Examples of the water-soluble acylphosphine oxides include those having an ion such as an alkali metal ion, an alkaline earth metal ion, a pyridinium ion, or an ammonium ion in the acylphosphine oxide molecule. Water-soluble acylphosphine oxides can be synthesized by the methods disclosed in, for example, European Patent No. 0009348 and Japanese Patent Laid-Open No. 57-197289.

[0082] Specific examples of the water-soluble acylphosphine oxides include monomethyl acetylphosphonate sodium salt, monomethyl(1-oxopropyl)phosphonate sodium salt, monomethylbenzoylphosphonate sodium salt, monomethyl(1-oxobutyl)phosphonate sodium salt, monomethyl(2-methyl-1-oxopropyl)phosphonate sodium salt, acetylphosphonate sodium salt, methyl 4-(hydroxymethoxyphosphinyl)-4-oxobutanoate sodium salt, methyl 4-oxo-4-phosphonobutanoate monosodium salt, acetylphenylphosphinate sodium salt, (1-oxopropyl)pentylphosphinate sodium salt, methyl 4-(hydroxypentylphosphinyl)-4-oxobutanoate sodium salt, acetylpentylphosphinate sodium salt, and acetylethylphosphinate. sodium salt, methyl 4-(hydroxymethylphosphinyl)-4-oxobutanoate lithium salt, 4-(hydroxymethylphosphinyl)-4-oxobutanoic acid dilithium salt, acetyl phosphinate sodium salt, acetyl methyl phosphinate oxime sodium salt, acetyl methyl phosphinate-O-benzyl oxime sodium salt, acetyl methyl phosphinate semicarbazone sodium salt, formyl methyl phosphinate sodium salt, methyl (1-oxopropyl) phosphinate sodium salt, acetyl methyl phosphinate thiosemicarbazone sodium salt, 2,4,6-trimethylbenzoylphenylphosphine oxide sodium salt, 2,4,6-trimethylbenzoylphenylphosphine oxide potassium salt, 2,4,6-trimethylbenzoylphenylphosphine oxide ammonium salt, and the like.

[0083] Among these (bis)acylphosphine oxides, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylmethoxyphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and sodium salts of 2,4,6-trimethylbenzoylphenylphosphine oxide are particularly preferred.

[0084] Examples of the thioxanthones include thioxanthone, 2-chlorothioxanthene-9-one, 2-hydroxy-3-(9-oxy-9H-thioxanthen-4-yloxy)-N,N,N-trimethylpropanaminium chloride, 2-hydroxy-3-(1-methyl-9-oxo-9H-thioxanthen-4-yloxy)-N,N,N-trimethyl-1-propanaminium chloride, and 2-hydroxy-3-(9-oxo-9H-thioxanthen-2-yloxy)-N,N,N-trimethyl-1-propanaminium chloride. ammonium chloride, 2-hydroxy-3-(3,4-dimethyl-9-oxo-9H-thioxanthen-2-yloxy)-N,N,N-trimethyl-1-propanaminium chloride, 2-hydroxy-3-(3,4-dimethyl-9H-thioxanthen-2-yloxy)-N,N,N-trimethyl-1-propanaminium chloride, 2-hydroxy-3-(1,3,4-trimethyl-9-oxo-9H-thioxanthen-2-yloxy)-N,N,N-trimethyl-1-propanaminium chloride, and the like.

[0085] Among these thioxanthones, 2-chlorothioxanthen-9-one and 2-hydroxy-3-(3,4-dimethyl-9H-thioxanthen-2-yloxy)-N,N,N-trimethyl-1-propanaminium chloride are preferred.

[0086] Examples of the ketals include benzyl dimethyl ketal and benzyl diethyl ketal.

[0087] Examples of the α-diketones include diacetyl, benzyl, camphorquinone, 2,3-pentadione, 2,3-octadione, 9,10-phenanthrenequinone, 4,4′-oxybenzyl, acenaphthenequinone, etc. Among these, camphorquinone is particularly preferred because it has a maximum absorption wavelength in the visible light region.

[0088] Examples of the coumarins include 3,3'-carbonylbis(7-diethylaminocoumarin), 3-(4-methoxybenzoyl)coumarin, 3-thienylcoumarin, 3-benzoyl-5,7-dimethoxycoumarin, 3-benzoyl-7-methoxycoumarin, 3-benzoyl-6-methoxycoumarin, 3-benzoyl-8-methoxycoumarin, 3-benzoylcoumarin, 7-methoxy-3-(p-nitrobenzoyl)coumarin, 3-(p-nitrobenzoyl)coumarin, 3,5-carbonylbis(7-methoxycoumarin), 3-benzoyl-6-bromobenzoyl coumarin, 3,3'-carbonylbiscoumarin, 3-benzoyl-7-dimethylaminocoumarin, 3-benzoylbenzo[f]coumarin, 3-carboxycoumarin, 3-carboxy-7-methoxycoumarin, 3-ethoxycarbonyl-6-methoxycoumarin, 3-ethoxycarbonyl-8-methoxycoumarin, 3-acetylbenzo[f]coumarin, 3-benzoyl-6-nitrocoumarin, 3-benzoyl-7-diethylaminocoumarin, 7-dimethylamino-3-(4-methoxybenzoyl)coumarin, 7-diethylamino-3-(4-methoxybenzoyl)coumarin )coumarin, 7-diethylamino-3-(4-diethylamino)coumarin, 7-methoxy-3-(4-methoxybenzoyl)coumarin, 3-(4-nitrobenzoyl)benzo[f]coumarin, 3-(4-ethoxycinnamoyl)-7-methoxycoumarin, 3-(4-dimethylaminocinnamoyl)coumarin, 3-(4-diphenylaminocinnamoyl)coumarin, 3-[(3-dimethylbenzothiazol-2-ylidene)acetyl]coumarin, 3-[(1-methylnaphtho[1,2-d]thiazol-2-ylidene)acetyl]coumarin, 3,3'-carbo Nylbis(6-methoxycoumarin), 3,3'-carbonylbis(7-acetoxycoumarin), 3,3'-carbonylbis(7-dimethylaminocoumarin), 3-(2-benzothiazolyl)-7-(diethylamino)coumarin, 3-(2-benzothiazolyl)-7-(dibutylamino)coumarin, 3-(2-benzimidazolyl)-7-(diethylamino)coumarin, 3-(2-benzothiazolyl)-7-(dioctylamino)coumarin, 3-acetyl-7-(dimethylamino)coumarin, 3,3'-carbonylbis(7-dibutylaminocoumarin), 3,Examples include 3'-carbonyl-7-diethylaminocoumarin-7'-bis(butoxyethyl)aminocoumarin, 10-[3-[4-(dimethylamino)phenyl]-1-oxo-2-propenyl]-2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H,5H,11H-[1]benzopyrano[6,7,8-ij]quinolizin-11-one, and 10-(2-benzothiazolyl)-2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H,5H,11H-[1]benzopyrano[6,7,8-ij]quinolizin-11-one.

[0089] Among these coumarins, 3,3'-carbonylbis(7-diethylaminocoumarin) and 3,3'-carbonylbis(7-dibutylaminocoumarin) are preferred.

[0090] Examples of the anthraquinones include anthraquinone, 1-chloroanthraquinone, 2-chloroanthraquinone, 1-bromoanthraquinone, 1,2-benzanthraquinone, 1-methylanthraquinone, 2-ethylanthraquinone, and 1-hydroxyanthraquinone.

[0091] Examples of the benzoin alkyl ether compounds include benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether.

[0092] Examples of the α-aminoketone compounds include 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one.

[0093] Among these photopolymerization initiators (E-1), at least one selected from the group consisting of (bis)acylphosphine oxides, α-diketones, and coumarins is preferred, which results in a dental composition that has excellent photocurability in the visible light region and near-ultraviolet light region and exhibits sufficient photocurability using any light source, such as a halogen lamp, a light-emitting diode (LED), or a xenon lamp.

[0094] (ii) Chemical polymerization initiator (E-2) As the chemical polymerization initiator (E-2), conventionally known initiators can be used, and organic peroxides are particularly preferred, such as ketone peroxides, hydroperoxides, diacyl peroxides, dialkyl peroxides, peroxyketals, peroxyesters, and peroxydicarbonates.

[0095] Examples of the ketone peroxide include methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, methylcyclohexanone peroxide, and cyclohexanone peroxide.

[0096] Examples of the hydroperoxide include 2,5-dimethylhexane-2,5-dihydroperoxide, diisopropylbenzene hydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide, and 1,1,3,3-tetramethylbutyl hydroperoxide.

[0097] Examples of the diacyl peroxide include acetyl peroxide, isobutyryl peroxide, benzoyl peroxide, decanoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, 2,4-dichlorobenzoyl peroxide, and lauroyl peroxide.

[0098] Examples of the dialkyl peroxide include di-t-butyl peroxide, dicumyl peroxide, t-butylcumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 1,3-bis(t-butylperoxyisopropyl)benzene, and 2,5-dimethyl-2,5-di(t-butylperoxy)-3-hexyne.

[0099] Examples of the peroxyketals include 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)cyclohexane, 2,2-bis(t-butylperoxy)butane, 2,2-bis(t-butylperoxy)octane, and 4,4-bis(t-butylperoxy)valeric acid n-butyl ester.

[0100] Examples of the peroxyester include α-cumyl peroxyneodecanoate, t-butyl peroxyneodecanoate, t-butyl peroxypivalate, 2,2,4-trimethylpentylperoxy-2-ethylhexanoate, t-amyl peroxy-2-ethylhexanoate, t-butyl peroxy-2-ethylhexanoate, di-t-butylperoxyisophthalate, di-t-butylperoxyhexahydroterephthalate, t-butylperoxy-3,3,5-trimethylhexanoate, t-butyl peroxyacetate, t-butyl peroxybenzoate, and t-butyl peroxyvaleric acid.

[0101] Examples of the peroxydicarbonate include di-3-methoxybutyl peroxydicarbonate, di(2-ethylhexyl) peroxydicarbonate, bis(4-t-butylcyclohexyl) peroxydicarbonate, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di(2-ethoxyethyl) peroxydicarbonate, and diallyl peroxydicarbonate.

[0102] Among these organic peroxides, diacyl peroxides are preferred, and benzoyl peroxide is particularly preferred, in view of the overall balance of safety, storage stability, and radical generating ability.

[0103] The polymerization initiator (E) preferably contains a photopolymerization initiator (E-1).

[0104] From the viewpoint of adhesiveness of the resulting dental composition, the content of the polymerization initiator (E) in the dental composition of the present invention is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, and most preferably 0.3% by mass or more. The content of the polymerization initiator (E) is preferably 10% by mass or less.

[0105] Polymerization accelerator (F) The dental composition of the present invention may further contain a polymerization accelerator (F). The polymerization accelerator (F) is preferably used together with the polymerization initiator (E). Known polymerization accelerators can be used as the polymerization accelerator (F), including amines, sulfinic acids (including salts), borate compounds, barbituric acid derivatives, triazine compounds, copper compounds, tin compounds, vanadium compounds, halogen compounds, aldehydes, thiol compounds, sulfites, hydrogen sulfites, and thiourea compounds. The polymerization accelerator (F) may be used alone or in combination of two or more.

[0106] The amines are divided into aliphatic amines and aromatic amines. Examples of the aliphatic amines include aliphatic primary amines such as n-butylamine, n-hexylamine, and n-octylamine; aliphatic secondary amines such as diisopropylamine, dibutylamine, and N-methylethanolamine; and aliphatic tertiary amines such as N-methyldiethanolamine, N-ethyldiethanolamine, Nn-butyldiethanolamine, N-lauryldiethanolamine, 2-(dimethylamino)ethyl methacrylate, N-methyldiethanolamine dimethacrylate, N-ethyldiethanolamine dimethacrylate, triethanolamine monomethacrylate, triethanolamine dimethacrylate, triethanolamine trimethacrylate, triethanolamine, trimethylamine, triethylamine, and tributylamine. Among these, tertiary aliphatic amines are preferred, and N-methyldiethanolamine and triethanolamine are more preferred, from the viewpoints of adhesion and storage stability of the dental composition.

[0107] Examples of the aromatic amine include N,N-bis(2-hydroxyethyl)-3,5-dimethylaniline, N,N-di(2-hydroxyethyl)-p-toluidine, N,N-bis(2-hydroxyethyl)-3,4-dimethylaniline, N,N-bis(2-hydroxyethyl)-4-ethylaniline, N,N-bis(2-hydroxyethyl)-4-isopropylaniline, N,N-bis(2-hydroxyethyl)-4-t-butylaniline, N,N-bis(2-hydroxyethyl)-3,5-diisopropylaniline, N,N-bis(2-hydroxyethyl)-3,5-di-t-butylaniline, N,N-dimethylaniline, N,N-dimethyl-p-toluidine, N,N-dimethyl-m-toluidine, N,N-diethyl-p-toluidine, N, Examples of the benzophenone include N-dimethyl-3,5-dimethylaniline, N,N-dimethyl-3,4-dimethylaniline, N,N-dimethyl-4-ethylaniline, N,N-dimethyl-4-isopropylaniline, N,N-dimethyl-4-t-butylaniline, N,N-dimethyl-3,5-di-t-butylaniline, ethyl 4-(N,N-dimethylamino)benzoate, methyl 4-(N,N-dimethylamino)benzoate, propyl 4-(N,N-dimethylamino)benzoate, n-butoxyethyl 4-(N,N-dimethylamino)benzoate, 2-[(meth)acryloyloxy]ethyl 4-(N,N-dimethylamino)benzoate, 4-(N,N-dimethylamino)benzophenone, butyl 4-dimethylaminobenzoate, and 4-(dimethylamino)benzonitrile. Among these, N,N-di(2-hydroxyethyl)-p-toluidine, ethyl 4-(N,N-dimethylamino)benzoate, n-butoxyethyl 4-(N,N-dimethylamino)benzoate, and 4-(N,N-dimethylamino)benzophenone are preferred from the viewpoint of imparting excellent adhesive properties to dental compositions.

[0108] Examples of the sulfinic acids include p-toluenesulfinic acid, sodium p-toluenesulfinate, potassium p-toluenesulfinate, lithium p-toluenesulfinate, calcium p-toluenesulfinate, benzenesulfinic acid, sodium benzenesulfinate, potassium benzenesulfinate, lithium benzenesulfinate, calcium benzenesulfinate, 2,4,6-trimethylbenzenesulfinic acid, sodium 2,4,6-trimethylbenzenesulfinate, potassium 2,4,6-trimethylbenzenesulfinate, lithium 2,4,6-trimethylbenzenesulfinate, and 2,4,6-trimethylbenzenesulfinate. Examples of suitable sulfinates include calcium sulfinate, 2,4,6-triethylbenzenesulfinic acid, sodium 2,4,6-triethylbenzenesulfinate, potassium 2,4,6-triethylbenzenesulfinate, lithium 2,4,6-triethylbenzenesulfinate, calcium 2,4,6-triethylbenzenesulfinate, 2,4,6-triisopropylbenzenesulfinic acid, sodium 2,4,6-triisopropylbenzenesulfinate, potassium 2,4,6-triisopropylbenzenesulfinate, lithium 2,4,6-triisopropylbenzenesulfinate, and calcium 2,4,6-triisopropylbenzenesulfinate. Among these, sodium benzenesulfinate, sodium p-toluenesulfinate, and sodium 2,4,6-triisopropylbenzenesulfinate are particularly preferred.

[0109] The borate compound is preferably an aryl borate compound, such as a borate compound having 1 to 4 aryl groups in one molecule.

[0110] Examples of borate compounds having one aryl group per molecule include trialkylphenylboron, trialkyl(p-chlorophenyl)boron, trialkyl(p-fluorophenyl)boron, trialkyl[3,5-bis(trifluoromethyl)phenyl]boron, trialkyl[3,5-bis(1,1,1,3,3,3-hexafluoro-2-methoxy-2-propyl)phenyl]boron, trialkyl(p-nitrophenyl)boron, trialkyl(m-nitrophenyl)boron, trialkyl(p-butylphenyl)boron, trialkyl(m-butylphenyl)boron, and trialkyl(p-butyloxophenyl). Examples of suitable alkyl groups include trialkyl(m-butyloxyphenyl)boron, trialkyl(m-butyloxyphenyl)boron, trialkyl(p-octyloxyphenyl)boron, trialkyl(m-octyloxyphenyl)boron (the alkyl group in each of the above examples is an n-butyl group, an n-octyl group, an n-dodecyl group, etc.), and salts thereof (sodium salt, lithium salt, potassium salt, magnesium salt, tetrabutylammonium salt, tetramethylammonium salt, tetraethylammonium salt, methylpyridinium salt, ethylpyridinium salt, butylpyridinium salt, methylquinolinium salt, ethylquinolinium salt, butylquinolinium salt, etc.).

[0111] Examples of borate compounds having two aryl groups in one molecule include dialkyldiphenylboron, dialkyldi(p-chlorophenyl)boron, dialkyldi(p-fluorophenyl)boron, dialkyldi[3,5-bis(trifluoromethyl)phenyl]boron, dialkyldi[3,5-bis(1,1,1,3,3,3-hexafluoro-2-methoxy-2-propyl)phenyl]boron, dialkyldi(p-nitrophenyl)boron, dialkyldi(m-nitrophenyl)boron, dialkyldi(p-butylphenyl)boron, dialkyldi(m-butylphenyl)boron, and dialkyldi(p-butyloxophenyl). dialkyldi(m-butyloxyphenyl)boron, dialkyldi(p-octyloxyphenyl)boron, dialkyldi(m-octyloxyphenyl)boron (the alkyl group in each of the above examples is an n-butyl group, an n-octyl group, an n-dodecyl group, or the like), and salts thereof (sodium salt, lithium salt, potassium salt, magnesium salt, tetrabutylammonium salt, tetramethylammonium salt, tetraethylammonium salt, methylpyridinium salt, ethylpyridinium salt, butylpyridinium salt, methylquinolinium salt, ethylquinolinium salt, butylquinolinium salt, or the like).

[0112] Examples of borate compounds having three aryl groups in one molecule include monoalkyltriphenylboron, monoalkyltri(p-chlorophenyl)boron, monoalkyltri(p-fluorophenyl)boron, monoalkyltri[3,5-bis(trifluoromethyl)phenyl]boron, monoalkyltri[3,5-bis(1,1,1,3,3,3-hexafluoro-2-methoxy-2-propyl)phenyl]boron, monoalkyltri(p-nitrophenyl)boron, monoalkyltri(m-nitrophenyl)boron, monoalkyltri(p-butylphenyl)boron, monoalkyltri(m-butylphenyl)boron, monoalkyltri( Examples of the alkyl group include monoalkyltri(m-butyloxyphenyl)boron, monoalkyltri(p-octyloxyphenyl)boron, monoalkyltri(m-octyloxyphenyl)boron (the alkyl group in each of the above examples is an n-butyl group, an n-octyl group, an n-dodecyl group, etc.), and salts thereof (sodium salt, lithium salt, potassium salt, magnesium salt, tetrabutylammonium salt, tetramethylammonium salt, tetraethylammonium salt, methylpyridinium salt, ethylpyridinium salt, butylpyridinium salt, methylquinolinium salt, ethylquinolinium salt, butylquinolinium salt, etc.).

[0113] Examples of borate compounds having four aryl groups in one molecule include tetraphenylboron, tetrakis(p-chlorophenyl)boron, tetrakis(p-fluorophenyl)boron, tetrakis[3,5-bis(trifluoromethyl)phenyl]boron, tetrakis[3,5-bis(1,1,1,3,3,3-hexafluoro-2-methoxy-2-propyl)phenyl]boron, tetrakis(p-nitrophenyl)boron, tetrakis(m-nitrophenyl)boron, tetrakis(p-butylphenyl)boron, tetrakis(m-butylphenyl)boron, tetrakis(p-butyloxyphenyl)boron, tetrakis(m-butyloxyphenyl)boron, tetrakis(p-octyloxyphenyl)boron, and tetrakis(m-octyloxyphenyl).

[0033] Examples of suitable hydroxyphenyls include (p-nitrophenyl)triphenylboron, (p-butyloxyphenyl)triphenylboron, (p-butyloxyphenyl)triphenylboron, (m-octyloxyphenyl)triphenylboron, (p-octyloxyphenyl)triphenylboron, and salts thereof (sodium salts, lithium salts, potassium salts, magnesium salts, tetrabutylammonium salts, tetramethylammonium salts, tetraethylammonium salts, methylpyridinium salts, ethylpyridinium salts, butylpyridinium salts, methylquinolinium salts, ethylquinolinium salts, butylquinolinium salts, etc.).

[0114] Among these aryl borate compounds, borate compounds having three or four aryl groups in one molecule are preferred from the viewpoint of storage stability. The aryl borate compounds may be used alone or in combination of two or more.

[0115] Examples of the barbituric acid derivatives include barbituric acid, 1,3-dimethylbarbituric acid, 1,3-diphenylbarbituric acid, 1,5-dimethylbarbituric acid, 5-butylbarbituric acid, 5-ethylbarbituric acid, 5-isopropylbarbituric acid, 5-cyclohexylbarbituric acid, 1,3,5-trimethylbarbituric acid, 1,3-dimethyl-5-ethylbarbituric acid, 1,3-dimethyl-5-n-butylbarbituric acid, 1,3-dimethyl-5-isobutylbarbituric acid, 1,3-dimethyl-5-cyclopentylbarbituric acid, 1,3-dimethyl-5-cyclohexylbarbituric acid, 1,3-dimethyl-5-phenylbarbituric acid, 1-cyclo Examples thereof include hexyl-1-ethylbarbituric acid, 1-benzyl-5-phenylbarbituric acid, 5-methylbarbituric acid, 5-propylbarbituric acid, 1,5-diethylbarbituric acid, 1-ethyl-5-methylbarbituric acid, 1-ethyl-5-isobutylbarbituric acid, 1,3-diethyl-5-butylbarbituric acid, 1-cyclohexyl-5-methylbarbituric acid, 1-cyclohexyl-5-ethylbarbituric acid, 1-cyclohexyl-5-octylbarbituric acid, 1-cyclohexyl-5-hexylbarbituric acid, 5-butyl-1-cyclohexylbarbituric acid, 1-benzyl-5-phenylbarbituric acid, thiobarbituric acids, and salts thereof. Salts of these barbituric acid derivatives include, for example, alkali metal salts and alkaline earth metal salts, more specifically, sodium 5-butylbarbiturate, sodium 1,3,5-trimethylbarbiturate, sodium 1-cyclohexyl-5-ethylbarbiturate, etc.

[0116] Particularly preferred barbituric acid derivatives are 5-butylbarbituric acid, 1,3,5-trimethylbarbituric acid, 1-cyclohexyl-5-ethylbarbituric acid, 1-benzyl-5-phenylbarbituric acid, and sodium salts thereof.

[0117] Examples of the triazine compound include 2,4,6-tris(trichloromethyl)-s-triazine, 2,4,6-tris(tribromomethyl)-s-triazine, 2-methyl-4,6-bis(trichloromethyl)-s-triazine, 2-methyl-4,6-bis(tribromomethyl)-s-triazine, 2-phenyl-4,6-bis(trichloromethyl)-s-triazine, 2-(p-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, and 2-(p-methylthiophenyl)-4,6-bis(trichloromethyl)-s-triazine. azine, 2-(p-chlorophenyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(2,4-dichlorophenyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(p-bromophenyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(p-tolyl)-4,6-bis(trichloromethyl)-s-triazine, 2-n-propyl-4,6-bis(trichloromethyl)-s-triazine, 2-(α,α,β-trichloroethyl)-4,6-bis(trichloromethyl)-s-triazine, 2-styryl-4,6- Bis(trichloromethyl)-s-triazine, 2-[2-(p-methoxyphenyl)ethenyl]-4,6-bis(trichloromethyl)-s-triazine, 2-[2-(o-methoxyphenyl)ethenyl]-4,6-bis(trichloromethyl)-s-triazine, 2-[2-(p-butoxyphenyl)ethenyl]-4,6-bis(trichloromethyl)-s-triazine, 2-[2-(3,4-dimethoxyphenyl)ethenyl]-4,6-bis(trichloromethyl)-s-triazine, 2-[2-(3,4,5-trimethoxyphenyl)ethenyl]-4, 6-bis(trichloromethyl)-s-triazine, 2-(1-naphthyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-biphenylyl)-4,6-bis(trichloromethyl)-s-triazine, 2-[2-{N,N-bis(2-hydroxyethyl)amino}ethoxy]-4,6-bis(trichloromethyl)-s-triazine, 2-[2-{N-hydroxyethyl-N-ethylamino}ethoxy]-4,6-bis(trichloromethyl)-s-triazine, 2-[2-{N-hydroxyethyl-N-methylamino}ethoxy]-4,6-bis(trichloromethyl)-s-triazine, 2-[2-{N-hydroxyethyl-N-methylamino}ethoxy]-4,Examples include 6-bis(trichloromethyl)-s-triazine and 2-[2-{N,N-diallylamino}ethoxy]-4,6-bis(trichloromethyl)-s-triazine.

[0118] Among these triazine compounds, 2,4,6-tris(trichloromethyl)-s-triazine is preferred in terms of polymerization activity. Furthermore, 2-phenyl-4,6-bis(trichloromethyl)-s-triazine, 2-(p-chlorophenyl)-4,6-bis(trichloromethyl)-s-triazine, and 2-(4-biphenylyl)-4,6-bis(trichloromethyl)-s-triazine are preferred in terms of storage stability. The triazine compounds may be used alone or in combination of two or more.

[0119] Examples of the copper compound include copper acetylacetonate, copper (II) acetate, copper oleate, copper (II) chloride, and copper (II) bromide.

[0120] Examples of the tin compound include di-n-butyltin dimaleate, di-n-octyltin dimaleate, di-n-octyltin dilaurate, di-n-butyltin dilaurate, etc. Among these, di-n-octyltin dilaurate and di-n-butyltin dilaurate are preferred.

[0121] The vanadium compound is preferably a tetravalent or pentavalent vanadium compound, such as divanadium(IV) tetroxide, vanadium oxide acetylacetonate(IV), vanadyl oxalate(IV), vanadyl sulfate(IV), oxobis(1-phenyl-1,3-butanedionato)vanadium(IV), bis(maltolato)oxovanadium(IV), vanadium(V) pentoxide, sodium metavanadate(V), and ammonium metavanadate(V).

[0122] Examples of the halogen compounds include dilauryldimethylammonium chloride, lauryldimethylbenzylammonium chloride, benzyltrimethylammonium chloride, tetramethylammonium chloride, benzyldimethylcetylammonium chloride, and dilauryldimethylammonium bromide.

[0123] Examples of the aldehydes include terephthalaldehyde and benzaldehyde derivatives. Examples of the benzaldehyde derivatives include dimethylaminobenzaldehyde, p-methoxybenzaldehyde, p-ethoxybenzaldehyde, and pn-octyloxybenzaldehyde. Among these, pn-octyloxybenzaldehyde is preferred from the viewpoint of adhesiveness.

[0124] Examples of the thiol compound include 3-mercaptopropyltrimethoxysilane, 2-mercaptobenzoxazole, decanethiol, and thiobenzoic acid.

[0125] Examples of the sulfite include sodium sulfite, potassium sulfite, calcium sulfite, and ammonium sulfite.

[0126] Examples of the bisulfite include sodium bisulfite and potassium bisulfite.

[0127] Examples of the thiourea compound include 1-(2-pyridyl)-2-thiourea, thiourea, methylthiourea, ethylthiourea, N,N'-dimethylthiourea, N,N'-diethylthiourea, N,N'-di-n-propylthiourea, N,N'-dicyclohexylthiourea, trimethylthiourea, triethylthiourea, tri-n-propylthiourea, tricyclohexylthiourea, tetramethylthiourea, tetraethylthiourea, tetra-n-propylthiourea, and tetracyclohexylthiourea.

[0128] From the viewpoint of adhesiveness of the resulting dental composition, the content of the polymerization accelerator (F) in the dental composition of the present invention is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more. The content of the polymerization accelerator (F) is preferably 10% by mass or less, more preferably 7% by mass or less, and even more preferably 5% by mass or less.

[0129] Organic solvent (G) It is preferable that the dental composition of the present invention further contains an organic solvent (G), since this can further improve adhesion, application properties, and penetration into tooth tissue, and can further prevent separation of the components in the dental composition.

[0130] Examples of organic solvents (G) include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-methyl-2-propanol, acetone, methyl ethyl ketone, tetrahydrofuran, diethyl ether, diisopropyl ether, hexane, toluene, chloroform, ethyl acetate, and butyl acetate. Among these, taking into consideration both safety to living organisms and ease of removal based on volatility, water-soluble organic solvents are preferred, specifically, ethanol, 2-propanol, 2-methyl-2-propanol, acetone, and tetrahydrofuran are preferred, and ethanol, 2-propanol, 2-methyl-2-propanol, and tetrahydrofuran are more preferred. The organic solvents (G) may be used alone or in combination of two or more.

[0131] The content of the organic solvent (G) in the dental composition of the present invention is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 8% by mass or more. The content of the organic solvent (G) is preferably 70% by mass or less, more preferably 50% by mass or less, and even more preferably 30% by mass or less. Depending on the embodiment, the organic solvent (G) may not be contained.

[0132] Filler (H) The dental composition of the present invention preferably further contains a filler (H). Such fillers (H) can be broadly classified into organic fillers, inorganic fillers, and organic-inorganic composite fillers. The filler (H) may be used singly or in combination of two or more. Examples of the use of two or more fillers include the use of fillers with different materials, particle size distributions, shapes, etc. Commercially available products can be used as the filler (H).

[0133] Examples of organic filler materials include polymethyl methacrylate, polyethyl methacrylate, methyl methacrylate-ethyl methacrylate copolymer, cross-linked polymethyl methacrylate, cross-linked polyethyl methacrylate, polyamide, polyvinyl chloride, polystyrene, chloroprene rubber, nitrile rubber, ethylene-vinyl acetate copolymer, styrene-butadiene copolymer, acrylonitrile-styrene copolymer, and acrylonitrile-styrene-butadiene copolymer. One type of organic filler may be used alone, or two or more types may be used in combination. The shape of the organic filler is not particularly limited.

[0134] Examples of inorganic filler materials include quartz, silica, alumina, silica-titania, silica-titania-barium oxide, silica-zirconia, silica-alumina, lanthanum glass, borosilicate glass, soda glass, barium glass, strontium glass, glass ceramic, aluminosilicate glass, barium boroaluminosilicate glass, strontium boroaluminosilicate glass, fluoroaluminosilicate glass, calcium fluoroaluminosilicate glass, strontium fluoroaluminosilicate glass, barium fluoroaluminosilicate glass, strontium calcium fluoroaluminosilicate glass, etc. One type of inorganic filler may be used alone, or two or more types may be used in combination.

[0135] The shape of the inorganic filler is not particularly limited, and examples of inorganic fillers include amorphous fillers and spherical fillers. From the viewpoint of improving the mechanical strength of the cured product, it is preferable to use a spherical filler as the inorganic filler. Here, a spherical filler can be a filler in which, when a photograph of the filler is taken with a scanning electron microscope (hereinafter abbreviated as SEM), the particles observed within a unit field of view are rounded and have an average uniformity of 0.6 or more, calculated by dividing the particle diameter in a direction perpendicular to the maximum diameter by the maximum diameter. When a spherical filler is used as the inorganic filler, the average particle diameter is preferably 0.1 μm or more, so that the filling rate of the spherical filler in the dental composition does not decrease and the mechanical strength of the cured product can be maintained. Furthermore, it is preferably 5 μm or less, so that a sufficient surface area can be obtained to maintain the mechanical strength of the cured product.

[0136] In order to adjust the fluidity of the dental composition, the inorganic filler may be surface-treated before use with a known surface treatment agent such as a silane coupling agent, if necessary. Examples of such surface treatment agents include silane coupling agents such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrichlorosilane, vinyltri(β-methoxyethoxy)silane, γ-methacryloyloxypropyltrimethoxysilane, 11-methacryloyloxyundecyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, and γ-aminopropyltriethoxysilane. One type of surface treatment agent may be used alone, or two or more types may be used in combination.

[0137] The organic-inorganic composite filler can be obtained by adding a monomer compound to the inorganic filler described above, forming a paste, polymerizing it, and pulverizing it. For example, TMPT filler (trimethylolpropane methacrylate and silica filler are mixed, polymerized, and then pulverized) can be used as the organic-inorganic composite filler. The shape of the organic-inorganic composite filler is not particularly limited.

[0138] The particle size of the filler (H) is not particularly limited, and its average particle size can be appropriately selected. From the viewpoints of the handleability of the resulting dental composition and the mechanical strength of the cured product, the average particle size of the filler (H) is preferably 0.001 μm or more, and preferably 50 μm or less, and more preferably 10 μm or less. In this specification, the average particle size of the filler (H) means the average particle size of the primary particles of the filler (H) (average primary particle size). In addition, when the inorganic filler is surface-treated with a surface treatment agent, the average particle size of the inorganic filler means the average particle size before the surface treatment.

[0139] The average particle size of the filler (H) can be determined by laser diffraction scattering or electron microscope observation of the particles. Specifically, laser diffraction scattering is a convenient method for measuring the particle size of particles 0.1 μm or larger, while electron microscope observation is a convenient method for measuring the particle size of ultrafine particles less than 0.1 μm. Laser diffraction scattering can be used to determine whether the particle size is 0.1 μm or larger.

[0140] In the laser diffraction scattering method, for example, the average particle size can be determined by measuring on a volume basis using a laser diffraction particle size distribution analyzer (e.g., "SALD-2300" manufactured by Shimadzu Corporation) using a 0.2% aqueous solution of sodium hexametaphosphate as a dispersion medium.

[0141] In electron microscope observation, for example, the average particle size can be determined by taking a photograph of the particles using a scanning electron microscope (such as the "S-4000" model manufactured by Hitachi, Ltd.) and measuring the particle sizes of the particles (200 or more) observed within a unit field of view in the photograph using image analysis particle size distribution measurement software (such as "Mac-View" manufactured by Mountec Co., Ltd.). In this case, the particle size of the particles is determined as the arithmetic mean of the longest and shortest lengths of the particles, and the average particle size is calculated from the number of particles and their particle sizes.

[0142] The content of the filler (H) in the dental composition of the present invention is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1.0% by mass or more, and is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 10% by mass or less.

[0143] Other ingredients The dental composition of the present invention may contain known additives within the range that does not impair the effects of the present invention. Such additives include pH adjusters, polymerization inhibitors, fluoride ion-releasing components, ultraviolet absorbers, thickeners, colorants, fluorescent agents, fragrances, antibacterial substances, etc. One type of additive may be used alone, or two or more types may be used in combination.

[0144] Examples of the antibacterial substance include cetylpyridinium chloride, benzalkonium chloride, (meth)acryloyloxydodecylpyridinium bromide, (meth)acryloyloxyhexadecylpyridinium chloride, (meth)acryloyloxydecylammonium chloride, and triclosan.

[0145] Examples of the polymerization inhibitor include hydroquinone, hydroquinone monomethyl ether, dibutylhydroquinone, dibutylhydroquinone monomethyl ether, t-butylcatechol, 2-t-butyl-4,6-dimethylphenol, 2,6-di-t-butylphenol, 3,5-di-t-butyl-4-hydroxytoluene, etc. The content of the polymerization inhibitor in the dental composition of the present invention is preferably 0.001 to 3.0 parts by mass.

[0146] The dental composition of the present invention can be prepared by any method without particular limitation, and can be obtained by blending the components. The obtained dental composition can be filled into a single container to form a one-liquid dental composition.

[0147] The dental composition of the present invention exhibits high adhesion not only to tooth structure but also to dental restorative materials made of metal, composite resin, porcelain, etc. Therefore, the dental composition of the present invention can be suitably used as a dental cement, dental adhesive, or dental primer, and is particularly suitable for dental adhesives or dental primers, many of which are hydrophilic. Here, the dental restorative material may be one that has been broken in the oral cavity. There are no particular limitations on the specific method of use of the dental composition of the present invention, and it can be used in a conventional manner.

[0148] When the dental composition of the present invention is used for bonding dental restorative materials, it may be used in combination with a primer such as a commercially available primer for metal bonding; or a tooth surface cleaner such as hypochlorite or hydrogen peroxide solution. [Example]

[0149] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The abbreviations used below are as follows.

[0150] [Organosilicon Compound (A)] A1: [ka] A2: [ka] A3: [ka] A4: [ka] A5: [ka] A6: [ka]

[0151] [Silane coupling agents not classified as organosilicon compounds (A)] a'1: [ka] a'2: [ka] a'3: [ka]

[0152] [Monomer (B) having an acidic group] MDP: 10-methacryloyloxydecyl dihydrogen phosphate

[0153] [Hydrophobic Monomer (D-1) Having No Acidic Group] Bis-GMA: 2,2-bis[4-(3-methacryloyloxy-2-hydroxypropoxy)phenyl]propane MAEA: N-methacryloyloxyethyl acrylamide

[0154] [Hydrophilic Monomer (D-2) Having No Acidic Group] HEMA: 2-hydroxyethyl methacrylate DEAA: N,N-diethylacrylamide

[0155] [Photopolymerization initiator (E-1)] CQ: Camphorquinone BAPO: Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide

[0156] [Polymerization accelerator (F)] DABE: Ethyl 4-(N,N-dimethylamino)benzoate DEPT: N,N-di(2-hydroxyethyl)-p-toluidine

[0157] [Solvent (G)] EtOH: ethanol

[0158] [Filler (H)] R972: Aerosil® R 972 fine particle silica manufactured by Nippon Aerosil Co., Ltd., average particle size: 16 nm

[0159] [Other ingredients] BHT: 3,5-di-t-butyl-4-hydroxytoluene (polymerization inhibitor)

[0160] [Examples 1 to 14 and Comparative Examples 1 to 3] One-component dental compositions were prepared by blending the components to the amounts shown in Tables 1 and 2. Using each of the resulting dental compositions, the viscosity and tensile bond strength to dental porcelain and dentin were measured according to the methods described below. The thixotropy of each dental composition was also evaluated. These results are shown in Tables 1 and 2. To evaluate the storage stability of the dental compositions, measurements were performed on the dental compositions immediately after preparation (immediately after preparation) and on the dental compositions after storage at 50°C for 4 weeks (after storage at 50°C for 4 weeks).

[0161] ·Viscosity measurement Measurements were performed at 30°C using a viscometer (Toki Sangyo Co., Ltd., TV-30E model viscometer, conforming to JIS K-7117-2:1999, cone-plate type) with a 0.8° x R24 cone rotor and a sample volume of 0.7 mL. Measurements were initiated after 1 minute of preheating, and the viscosity was measured after 3 minutes (n=2). The viscosity immediately after preparation was set to 100%, and the viscosity increase (%) after 4 weeks of storage at 50°C was calculated using the following formula: Viscosity increase rate (%) = {(viscosity after 4 weeks of storage at 50°C) - (viscosity immediately after adjustment)} / (viscosity immediately after adjustment) × 100

[0162] Measurement of tensile bond strength to dental porcelain Dental porcelain (feldspar ceramics, "VITABLOCS (registered trademark) Mark II") was polished under running water with #1000 silicon carbide paper (manufactured by Nihon Kenshi Co., Ltd.). After polishing, the surface was dried by air blowing. After drying, a piece of adhesive tape with a thickness of approximately 150 μm and a circular hole with a diameter of 5 mm was attached to the smooth surface to define the adhesive area.

[0163] The dental compositions prepared in each Example or Comparative Example were applied to the round holes using a brush, left for 3 seconds, and then dried by blowing air over the surface until the applied dental compositions lost their fluidity. Subsequently, the applied dental compositions were cured by irradiating them with light for 10 seconds using a dental visible light irradiator (manufactured by Morita Corporation, product name "Pencure 2000").

[0164] The surface of the cured dental composition was filled with a dental filling composite resin (manufactured by Kuraray Noritake Dental Co., Ltd., product name "Clearfil (registered trademark) AP-X") and covered with a release film (polyester). Next, a slide glass was placed on the release film and pressed against it to smooth the surface coated with the dental filling composite resin. Next, the dental filling composite resin was irradiated with light for 20 seconds using the dental visible light irradiator through the release film to cure the dental filling composite resin.

[0165] One end face (circular cross section) of a stainless steel cylindrical rod (7 mm diameter, 2.5 cm length) was bonded to the surface of the cured dental filling composite resin obtained using a commercially available dental resin cement (manufactured by Kuraray Noritake Dental Co., Ltd., product name "Panavia (registered trademark) 21"). After bonding, the sample was left to stand at room temperature for 30 minutes and then immersed in distilled water to obtain a test sample for the adhesion test. Ten test samples for the adhesion test were prepared and left to stand for 24 hours in an incubator maintained at 37°C. After further standing for 240 hours in an incubator maintained at 70°C, the tensile bond strength was measured under the following conditions.

[0166] The tensile adhesive strength of the adhesive test sample was measured using a universal testing machine (Shimadzu Corporation, Autograph "AG-I 100kN") at a crosshead speed of 2 mm / min, and the average value was calculated.

[0167] Measurement of tensile bond strength to dentin The labial surfaces of bovine mandibular anterior teeth were polished under running water with #80 silicon carbide paper (Nihon Kenshi Co., Ltd.) to obtain samples with exposed flat dentin surfaces. The obtained samples were further polished under running water with #1000 silicon carbide paper (Nihon Kenshi Co., Ltd.). After polishing, the surface was dried by air blowing. After drying, adhesive tape approximately 150 μm thick with a 3 mm diameter circular hole was attached to the smooth surface to define the adhesive area.

[0168] The dental compositions prepared in each Example or Comparative Example were applied to the round holes using a brush, left for 3 seconds, and then dried by blowing air over the surface until the applied dental compositions lost their fluidity. Subsequently, the applied dental compositions were cured by irradiating them with light for 10 seconds using a dental visible light irradiator (manufactured by Morita Corporation, product name "Pencure 2000").

[0169] The surface of the cured dental composition was filled with a dental filling composite resin (manufactured by Kuraray Noritake Dental Co., Ltd., product name "Clearfil® AP-X") and covered with a release film (polyester). A glass slide was then placed on the release film and pressed against it to smooth the coated surface of the dental filling composite resin. The dental filling composite resin was then irradiated with light for 20 seconds using the dental visible light irradiator through the release film to cure the dental filling composite resin. One end face (circular cross section) of a stainless steel cylindrical rod (7 mm diameter, 2.5 cm length) was bonded to the surface of the cured dental filling composite resin using commercially available dental resin cement (manufactured by Kuraray Noritake Dental Co., Ltd., product name "Panavia® 21"). After bonding, the sample was left at room temperature for 30 minutes and then immersed in distilled water to obtain a test sample for adhesion testing. Ten test samples for the adhesion test were prepared and left to stand in an incubator maintained at 37°C for 24 hours. To evaluate adhesion durability, the samples were subjected to 4,000 thermal cycles, each cycle consisting of alternating immersion in 4°C cold water and 60°C hot water for 1 minute, and then the tensile adhesive strength was measured under the following conditions.

[0170] The tensile adhesive strength of the adhesive test sample was measured using a universal testing machine (Shimadzu Corporation, Autograph "AG-I 100kN") at a crosshead speed of 2 mm / min, and the average value was calculated.

[0171] Thixotropy evaluation The prepared dental composition was filled into a bottle container of "Clearfil (registered trademark) Universal Bond Quick ER" (manufactured by Kuraray Noritake Dental Co., Ltd.) in an amount of 5 mL, and then stored at 50°C for 4 weeks (n=3). If the dental composition could be easily dripped from the container after storage, it was marked as "○", and if even one drop was not possible or was insufficient, it was marked as "×". When dripping the dental composition from the container, care was taken to avoid impact or shaking as much as possible.

[0172] [Table 1]

[0173] [Table 2]

[0174] As shown in Tables 1 and 2, the dental compositions according to the present invention (Examples 1 to 14) exhibited sufficient dentin bond strength. The viscosity increase rate was 30% or less, and the thixotropy evaluation was also favorable. Furthermore, even after 4 weeks of storage at 50°C, the adhesive strength to porcelain was 10.0 MPa or more, suggesting that contact between the organosilicon compounds (A) was suppressed and that self-condensation reactions between the silane coupling agents were less likely to occur. In contrast, the dental compositions (Comparative Examples 1 to 3) that did not contain the organosilicon compound (A) and used a silane coupling agent that does not fall under the category of organosilicon compound (A) exhibited viscosity increase rates of 165% or more, and the viscosity increased during 4 weeks of storage at 50°C, resulting in poor thixotropy evaluation. Furthermore, even after 4 weeks of storage at 50°C, the adhesive strength to porcelain was 10.0 MPa or less, suggesting that self-condensation reactions between the silane coupling agents occurred. As described above, it was confirmed that the dental composition of the present invention exhibits superior effects compared to Comparative Examples 1 and 2 corresponding to Patent Document 3, and Comparative Example 3 which used a silane coupling agent that has been commonly used in the past.

Claims

1. A dental composition comprising an organosilicon compound (A) represented by the following general formula (1): Z―X m ―Y―SiR 1 n R 2 (3-n) (1) (In the formula, Z represents a (meth)acryloyloxy group, a (meth)acrylamide group, a mercapto group, or an epoxy group, and X represents a group represented by the following formula (2), (3), or (4): —CH 2 O— (2) -CH2CH2O- (3) -CH2CH2CH2O- (4) Y represents a divalent hydrocarbon group having 1 to 30 carbon atoms; R 1 represents a group selected from the group consisting of an alkyl group, an aryl group, and an aralkyl group; R 2 represents an alkoxy group having 1 to 5 carbon atoms, m represents an integer of 1 to 8, and n represents 0, 1, or 2. 1 , R 2 and when there are a plurality of X's, they may be the same or different.

2. 2. The dental composition according to claim 1, wherein X has 1 to 3 carbon atoms.

3. 3. The dental composition according to claim 1, wherein m is an integer of 1 to 4.

4. The dental composition according to any one of claims 1 to 3, wherein n is 1 or 2.

5. The dental composition according to any one of claims 1 to 4, wherein Z is a (meth)acryloyloxy group.

6. 6. The dental composition according to claim 1, wherein the content of the organosilicon compound (A) is 0.1 to 50% by mass.

7. The dental composition according to any one of claims 1 to 6, further comprising a monomer (B) having an acidic group.

8. The dental composition according to claim 7 , wherein the monomer (B) having an acidic group includes a monomer having a phosphate group.

9. The dental composition according to any one of claims 1 to 8, further comprising water (C).

10. The dental composition according to any one of claims 1 to 9, further comprising a monomer (D) having no acidic group.

11. 11. The dental composition according to claim 10, wherein the monomer (D) having no acidic group includes a hydrophilic monomer (D-2) having no acidic group.

12. 12. The dental composition according to claim 11, wherein the hydrophilic monomer (D-2) having no acidic group is contained in an amount of 8 to 90% by mass based on the mass of all monomers contained in the dental composition.

13. A dental adhesive comprising the dental composition according to any one of claims 1 to 12.

14. An organosilicon compound (A) represented by the following general formula (1): Z―X m ―Y―SiR 1 n R 2 (3-n) (1) (In the formula, Z represents a (meth)acryloyloxy group, a (meth)acrylamide group, or a mercapto group; X represents a group represented by the following formula (2) or (3); Y represents a divalent hydrocarbon group having 2 carbon atoms; R 1 represents a group selected from the group consisting of an alkyl group, an aryl group, and an aralkyl group; R 2 represents an alkoxy group having 1 to 5 carbon atoms, m represents an integer of 1 to 8, and n represents 0, 1, or 2. 1 , R 2 and when there are a plurality of X's, they may be the same or different. ―CH 2 O― (22) ―CH 2 CH 2 O― (3)

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