JP7578526B2 - Dental restoration kit - Google Patents

Description

The present invention relates to a dental restoration kit. More specifically, the dental restoration kit of the present invention relates to a dental restoration kit that includes an aqueous solution containing diamine silver fluoride and a self-adhesive dental composite resin, which can treat the tooth surface with an aqueous solution containing diamine silver fluoride and then restore the tooth with a specific self-adhesive dental composite resin, thereby suppressing caries (initial caries, secondary caries) or dentin hypersensitivity and masking blackening caused by diamine silver fluoride.

Aqueous solutions containing diamine silver fluoride are known to inhibit the progression of early caries, inhibit secondary caries, and inhibit dentin hypersensitivity (dentin desensitization), and are primarily used as preventive treatment for children who are difficult to treat or elderly people who have difficulty visiting a dental clinic. However, there is an issue that application of diamine silver fluoride can cause dentin to turn black, and its application to permanent teeth (especially front teeth) is not recommended.

In order to suppress blackening caused by silver diamine fluoride, attempts have been made to apply an aqueous solution of potassium iodide to dentin after treatment with silver diamine fluoride, but it is known that the application of an aqueous solution of potassium iodide may suppress the action of silver diamine fluoride (Non-Patent Document 1).

In addition, research into suppressing blackening caused by diamine silver fluoride has attempted to apply an aqueous potassium iodide solution to the tooth structure after application of diamine silver fluoride, and then fill and restore it with resin-reinforced glass ionomer cement or glass ionomer cement (Non-Patent Document 2), but the prior art does not know of a method that maintains the efficacy of diamine silver fluoride while suppressing blackening.

On the other hand, the functions of an aqueous solution containing diamine silver fluoride are known to be the fixation of dentin collagen and the strengthening of dentin through the effect of the eluted fluoride ions. For this reason, an aqueous solution of diamine silver fluoride is sometimes used for the purpose of pretreatment of the tooth tissue after cavity formation for direct filling restoration using a conventional bonding material and composite resin. In such cases, it is thought possible to suppress blackening by using an aqueous solution of potassium iodide in combination. However, when an aqueous solution of diamine silver fluoride is used in combination with a bonding material, the reaction between the acidic monomer contained in the bonding material and the silver ions inhibits the penetration of the silver ions into the tooth tissue, and the efficacy of the aqueous solution of diamine silver fluoride (such as inhibiting the progression of dental caries) may be suppressed, as with the aqueous solution of potassium iodide. In the prior art, no method is known for maintaining the efficacy of diamine silver fluoride while suppressing blackening.

Zhao IS, Mei ML, Burrow MF, Lo EC, Chu CH, Effect of Silver Diamine Fluoride and Potassium Iodide Treatment of Secondary Caries Prevention and Tooth Discolouration in Cervical Glass Ionomer Cement Restoration. Int J. Mol. Sci. 18(2), 2017. Vinh Nguyen, Cody Neill, Joel Felsenfeld and Carolyn Primus, Potassium Iodide. The Solution to Silver Diamine Fluoride Discoloration?, Adv Dent Oral Health,Vol. 5, Issue 1, 2017.

The present invention aims to provide a dental restoration kit that includes an aqueous solution containing diamine silver fluoride and a self-adhesive dental composite resin, which maintains the clinical effects of diamine silver fluoride (e.g., prevention of dental caries, inhibition of the progression of dental caries, inhibition of dentin hypersensitivity, etc.) and can mask the blackening caused by diamine silver fluoride.

The inventors discovered that a dental restoration kit comprising an aqueous solution containing diammine silver fluoride of the present invention and a specific self-adhesive dental composite resin can solve the above-mentioned problems without impeding the penetration of silver ions into the tooth structure due to a reaction between the silver ions and the acidic monomers contained in the self-adhesive dental composite resin, and after further investigations, they have completed the present invention.

That is, the present invention includes the following inventions.
[1] A self-adhesive dental composite resin (X) containing a monomer (a) having an acidic group, a monomer (b) not having an acidic group, a polymerization initiator (c), and a filler (d);
and an aqueous solution (Y) containing diamine silver fluoride (e),
A dental restoration kit, wherein the transparency (ΔL*) of the self-adhesive dental composite resin (X) is 25 or less.
[2] The dental restoration kit described in [1], wherein the content of the filler (d) is 50 parts by mass or more in a total amount of 100 parts by mass of the self-adhesive dental composite resin (X).
[3] The dental restoration kit according to [1] or [2], wherein the filler (d) comprises an inorganic filler (d-1), and the average particle diameter of the inorganic filler (d-1) is 0.001 to 50 μm.
[4] The dental restoration kit according to [3], wherein the inorganic filler (d-1) comprises a combination of at least one selected from the group consisting of quartz, silica, silica-zirconia, and barium glass, and silica-coated ytterbium fluoride.
[5] The dental restoration kit according to [3] or [4], further comprising an inorganic filler (d-1a) having a refractive index of 1.9 or more in addition to the inorganic filler (d-1), and the content of the inorganic filler (d-1a) is 0.001 parts by mass or more per 100 parts by mass of the total amount of the self-adhesive dental composite resin (X).
[6] The dental restoration kit according to [5], wherein the inorganic filler (d-1a) comprises at least one selected from the group consisting of titanium oxide, zirconium oxide, and zinc oxide.

The dental restoration kit of the present invention provides a dental restoration kit that includes an aqueous solution containing diamine silver fluoride and a self-adhesive dental composite resin, which can maintain the clinical effects of diamine silver fluoride (e.g., prevention of dental caries, inhibition of the progression of dental caries, inhibition of dentin hypersensitivity, etc.) and mask the blackening caused by diamine silver fluoride, by treating the tooth surface with an aqueous solution containing diamine silver fluoride and then restoring it with a specific self-adhesive dental composite resin.

In addition, the dental restoration kit of the present invention is expected to have a sustained antibacterial effect due to the aqueous solution containing diamine silver fluoride, so it can also be suitably used for so-called shield restoration, which seals dentin softened by caries without removing it.

The dental restoration kit of the present invention comprises a self-adhesive dental composite resin (X) and an aqueous solution (Y) containing diamine silver fluoride (e), and the transparency (ΔL*) of the self-adhesive dental composite resin (X) is 25 or less.

The components used in the self-adhesive dental composite resin (X) of the present invention are described below.

<Monomer (a) Having an Acidic Group>
The self-adhesive dental composite resin (X) of the present invention requires a monomer (a) having an acidic group from the viewpoint of adhesion to tooth structure. A radical monomer is preferably used for the self-adhesive dental composite resin (X). Specific examples of the radical monomer in the monomer (a) having an acidic group include (meth)acrylate monomers, (meth)acrylamide monomers, esters such as α-cyanoacrylic acid, (meth)acrylic acid, α-halogenated acrylic acid, crotonic acid, cinnamic acid, sorbic acid, maleic acid, and itaconic acid, vinyl esters, vinyl ethers, mono-N-vinyl derivatives, and styrene derivatives. Among these, (meth)acrylate monomers and (meth)acrylamide monomers are preferred from the viewpoint of curability.

The monomer (a) having an acidic group used in the present invention may be, for example, a monomer having at least one acidic group such as a phosphoric acid group, a pyrophosphate group, a thiophosphate group, a phosphonic acid group, a carboxylic acid group, or a sulfonic acid group. The monomer (a) having an acidic group may be used alone or in appropriate combination of two or more types. Specific examples of the monomer (a) having an acidic group are given below.

Examples of monomers 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)acryloyloxyethyl dihydrogen phosphate, 9-(meth)acryloyloxypropyl dihydrogen phosphate, 10-(meth)acryloyloxybutyl dihydrogen phosphate, 11-(meth)acryloyloxybutyl dihydrogen phosphate, 12-(meth)acryloyloxybutyl dihydrogen phosphate, 13-(meth)acryloyloxypentyl dihydrogen phosphate, 14-(meth)acryloyloxyhexyl dihydrogen phosphate, 15-(meth)acryloyloxyhexyl dihydrogen phosphate, 16-(meth)acryloyloxyhexyl dihydrogen phosphate, 17-(meth)acryloyloxyheptyl dihydrogen phosphate, 18-(meth)acryloyloxyhexyl dihydrogen phosphate, 19-(meth)acryloyloxyhexyl dihydrogen phosphate, 20-(meth)acryloyloxyhexyl dihydrogen phosphate, 21-(meth)acryloyloxyhexyl dihydrogen phosphate, 22-(meth)acryloyloxyhexyl dihydrogen phosphate, 23-(meth)acryloyloxyhexyl dihydrogen phosphate, 24-(meth)acryloyloxyhexyl dihydrogen phosphate, 25-(meth)acryloyloxyhexyl dihydrogen phosphate, 26-(meth)acryloyloxyhexyl dihydrogen phosphate, 27-(meth)acryloyloxyhexyl di acryloyloxyoctyl dihydrogen phosphate, 9-(meth)acryloyloxynonyl dihydrogen phosphate, 10-(meth)acryloyloxydecyl dihydrogen phosphate, 11-(meth)acryloyloxyundecyl dihydrogen phosphate, 12-(meth)acryloyloxydodecyl dihydrogen phosphate, 16-(meth)acryloyloxyhexadecyl dihydrogen phosphate, 20-(meth)acryloyloxyicosyl dihydrogen phosphate phosphate, bis[2-(meth)acryloyloxyethyl]hydrogen phosphate, bis[4-(meth)acryloyloxybutyl]hydrogen phosphate, bis[6-(meth)acryloyloxyhexyl]hydrogen phosphate, bis[8-(meth)acryloyloxyoctyl]hydrogen phosphate, bis[9-(meth)acryloyloxynonyl]hydrogen phosphate, bis[10-(meth)acryloyloxydecyl]hydrogen phosphate, 1,3- These include di(meth)acryloyloxypropyl dihydrogen phosphate, 2-(meth)acryloyloxyethyl phenyl hydrogen phosphate, 2-(meth)acryloyloxyethyl-(2-bromoethyl)hydrogen phosphate, 2-methacryloyloxyethyl-(4-methoxyphenyl)hydrogen phosphate, 2-methacryloyloxypropyl-(4-methoxyphenyl)hydrogen phosphate, and their acid chlorides, alkali metal salts, and amine salts.

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 their acid chlorides, alkali metal salts, and amine salts.

Examples of monomers 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, and 8-(meth)acryloyloxyoctyl dihydrogenthiophosphate. Phosphate, 9-(meth)acryloyloxynonyl dihydrogen thiophosphate, 10-(meth)acryloyloxydecyl dihydrogen thiophosphate, 11-(meth)acryloyloxyundecyl dihydrogen thiophosphate, 12-(meth)acryloyloxydodecyl dihydrogen thiophosphate, 16-(meth)acryloyloxyhexadecyl dihydrogen thiophosphate, 20-(meth)acryloyloxyicosyl dihydrogen thiophosphate, and their acid chlorides, alkali metal salts, and ammonium salts.

Examples of monomers having a phosphonic acid group include 2-(meth)acryloyloxyethyl phenylphosphonate, 5-(meth)acryloyloxypentyl-3-phosphonopropionate, 6-(meth)acryloyloxyhexyl-3-phosphonopropionate, 10-(meth)acryloyloxydecyl-3-phosphonopropionate, 6-(meth)acryloyloxyhexyl-3-phosphonoacetate, 10-(meth)acryloyloxydecyl-3-phosphonoacetate, and acid chlorides, alkali metal salts, and ammonium salts thereof.

Examples of monomers having a carboxylic acid group include monofunctional (meth)acrylic acid esters having one carboxyl group or its acid anhydride group in the molecule, and monofunctional (meth)acrylic acid esters having multiple carboxyl groups or their acid anhydride groups in the molecule.

Examples of monofunctional monomers having one carboxyl group or its acid anhydride group in the molecule include (meth)acrylic acid, N-(meth)acryloylglycine, N-(meth)acryloylaspartic acid, 2-(meth)acryloyloxyethyl hydrogen succinate, 2-(meth)acryloyloxyethyl hydrogen phthalate, 2-(meth)acryloyloxyethyl hydrogen maleate, O-(meth)acryloyltyrosine, N-(meth)acryloyltyrosine, Examples include acryloylphenylalanine, N-(meth)acryloyl-p-aminobenzoic acid, N-(meth)acryloyl-o-aminobenzoic acid, 2-(meth)acryloyloxybenzoic acid, 3-(meth)acryloyloxybenzoic acid, 4-(meth)acryloyloxybenzoic acid, N-(meth)acryloyl-5-aminosalicylic acid, N-(meth)acryloyl-4-aminosalicylic acid, and compounds in which the carboxyl group of these compounds has been converted to an acid anhydride group.

Examples of monofunctional monomers having multiple carboxyl groups or their acid anhydride groups in the molecule include, for example, 6-(meth)acryloyloxyhexane-1,1-dicarboxylic acid, 9-(meth)acryloyloxynonane-1,1-dicarboxylic acid, 10-(meth)acryloyloxydecane-1,1-dicarboxylic acid, 11-(meth)acryloyloxyundecane-1,1-dicarboxylic acid, 12-(meth)acryloyloxydodecane-1,1-dicarboxylic acid, 13-(meth)acryloyloxytridecane-1,1-dicarboxylic acid, 4-(meth)acryloyloxyethyl trimellitate, 4-(meth)acryloyloxyethyl trimellitate anhydride ... Examples of such acryloyloxyethyl include butyl trimellitate, 4-(meth)acryloyloxyhexyl trimellitate, 4-(meth)acryloyloxydecyl trimellitate, 2-(meth)acryloyloxyethyl-3'-(meth)acryloyloxy-2'-(3,4-dicarboxybenzoyloxy)propyl succinate, 6-(meth)acryloyloxyethyl naphthalene-1,2,6-tricarboxylic anhydride, 6-(meth)acryloyloxyethyl naphthalene-2,3,6-tricarboxylic anhydride, 4-(meth)acryloyloxyethyl carbonylpropionoyl-1,8-naphthalic anhydride, and 4-(meth)acryloyloxyethyl naphthalene-1,8-tricarboxylic anhydride.

Examples of monomers having a sulfonic acid group include 2-sulfoethyl (meth)acrylate.

Among the above-mentioned monomers (a) having an acidic group, from the viewpoint of good adhesive strength when used as a self-adhesive dental composite resin (X), it is preferable to include a monomer having a phosphoric acid group or a monomer having a carboxylic acid group, and examples of such monomers 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, and the like. Hydrogen phosphate, 7-(meth)acryloyloxyheptyl dihydrogen phosphate, 8-(meth)acryloyloxyoctyl dihydrogen phosphate, 9-(meth)acryloyloxynonyl dihydrogen phosphate, 10-(meth)acryloyloxydecyl dihydrogen phosphate, 11-(meth)acryloyloxyundecyl dihydrogen phosphate, 12-(meth)acryloyloxydodecyl dihydrogen phosphate, 16-(meth)acryloyloxyhexadecyl dihydrogen phosphate, 20-(meth)acryloyloxyicosyl dihydrogen phosphate, 4-(meth)acryloyloxyethyl trimellitate anhydride, 4-(meth)acryloyloxyethyl trimellitate, 11-(meth)acryloyloxyundecane-1,1-dicarboxylic acid, and a mixture of 2-methacryloyloxyethyl dihydrogen phosphate and bis(2-methacryloyloxyethyl)hydrogen phosphate are more preferred, and 8-(meth)acryloyloxyoctyl dihydrogen phosphate, 9-(meth)acryloyloxynonyl Dihydrogen phosphate, 10-(meth)acryloyloxydecyl dihydrogen phosphate, 11-(meth)acryloyloxyundecyl dihydrogen phosphate, 12-(meth)acryloyloxydodecyl dihydrogen phosphate, 16-(meth)acryloyloxyhexadecyl dihydrogen phosphate, and 20-(meth)acryloyloxyicosyl dihydrogen phosphate are more preferred, and from the viewpoint of balance with curability, 10-(meth)acryloyloxydecyl dihydrogen phosphate is the most preferred.

The content of the monomer (a) having an acidic group in the self-adhesive dental composite resin (X) of the present invention is not particularly limited, but from the viewpoint of adhesion to tooth structure, it is preferably 1 to 40 parts by mass, more preferably 2.5 to 35 parts by mass, and even more preferably 5 to 30 parts by mass, per 100 parts by mass of the total amount of monomers.

<Monomer (b) Having No Acidic Group>
Examples of the monomer (b) having no acidic group in the present invention include an asymmetric acrylamide-methacrylic acid ester compound (b-1); a hydrophobic monomer (b-2) having no acidic group and having a solubility in water at 25° C. of less than 10% by mass (hereinafter, sometimes simply referred to as "hydrophobic monomer (b-2)"); and a hydrophilic monomer (b-3) having no acidic group and having a solubility in water at 25° C. of 10% by mass or more (hereinafter, sometimes simply referred to as "hydrophilic monomer (b-3)"). The monomer (b) having no acidic group may be used alone or in combination of two or more kinds. In the present invention, a compound which does not have an acidic group and contains an acrylamide group and a methacryloyloxy group is defined as an asymmetric acrylamide-methacrylic acid ester compound (b-1), and a compound which does not have an acidic group and is not included in the asymmetric acrylamide-methacrylic acid ester compound (b-1) is classified into a hydrophobic monomer (b-2) and a hydrophilic monomer (b-3) depending on the degree of hydrophilicity.

Asymmetric acrylamide-methacrylate compound (b-1)
A preferred embodiment of the present invention is a self-adhesive dental composite resin (X) containing an asymmetric acrylamide-methacrylate compound (b-1). The asymmetric acrylamide-methacrylate compound (b-1) is preferably a compound represented by the following general formula (1) in order to improve adhesion to tooth structure.

式中、Ｚは置換基を有していてもよいＣ₁～Ｃ₈の直鎖状又は分岐鎖状の脂肪族基又は芳香族基であって、前記脂肪族基は、－Ｏ－、－Ｓ－、－ＣＯ－、－ＣＯ－Ｏ－、－Ｏ－ＣＯ－、－ＮＲ¹－、－ＣＯ－ＮＲ¹－、－ＮＲ¹－ＣＯ－、－ＣＯ－Ｏ－ＮＲ¹－、－Ｏ－ＣＯ－ＮＲ¹－及び－ＮＲ¹－ＣＯ－ＮＲ¹－からなる群より選ばれる少なくとも１個の結合基によって中断されていてもよい。Ｒ¹は、水素原子又は置換基を有していてもよいＣ₁～Ｃ₈の直鎖状又は分岐鎖状の脂肪族基を表す。

In the formula, Z represents a _C1 to _C8 linear or branched aliphatic group or aromatic group which may have a substituent, and the aliphatic group may be interrupted by at least one bonding group selected from the group consisting of -O-, -S-, -CO-, -CO- ^O- , -O-CO-, ^-NR1- , -CO ^{- NR1-} , ^-NR1- CO-, -CO-O- ^NR1- , -O-CO-NR1- and -NR1-CO-NR1-. ^R1 represents a hydrogen atom or _{a C1} to ^C8 linear or branched aliphatic group which may have a substituent.

Z is a moiety for adjusting the hydrophilicity of the asymmetric acrylamide-methacrylic acid ester compound (b-1). The C ₁ -C ₈ aliphatic group which may have a substituent represented by Z may be any of a saturated aliphatic group (alkylene group, cycloalkylene group (e.g., 1,4-cyclohexylene group, etc.)) and an unsaturated aliphatic group (alkenylene group, alkynylene group), and is preferably a saturated aliphatic group (alkylene group) from the viewpoint of availability or ease of production and chemical stability. Z is preferably a linear or branched C _{1 -C 4 aliphatic group which may have a substituent, and more preferably a linear or branched C 2 -C 4 aliphatic group which may have a substituent, from the viewpoint of adhesion to tooth substance and polymerization curing property. As the aliphatic group, an alkylene group is preferable. Examples of the C 1 -C 8 alkylene group include} a methylene group, an ethylene group, an n-propylene group, an isopropylene group, and an n-butylene group.

Examples of aromatic groups that may have a substituent represented by Z include aryl groups and aromatic heterocyclic groups. As the aromatic group, aryl groups are more preferable than aromatic heterocyclic groups. The heterocycle of the aromatic heterocyclic group is generally unsaturated. The aromatic heterocycle is preferably a 5-membered or 6-membered ring. As an aryl group, for example, a phenyl group is preferable. As an aromatic heterocyclic group, for example, a furan group, a thiophene group, a pyrrole group, an oxazole group, an isoxazole group, a thiazole group, an isothiazole group, an imidazole group, a pyrazole group, a furazan group, a triazole group, a pyran group, a pyridine group, a pyridazine group, a pyrimidine group, a pyrazine group, and a 1,3,5-triazine group are preferable. Among the aromatic groups, a phenyl group is particularly preferable.

The aliphatic group in ^R1 may be either a saturated aliphatic group (alkyl group) or an unsaturated aliphatic group (alkenyl group, alkynyl group), and from the viewpoint of availability or ease of production and chemical stability, a saturated aliphatic group (alkyl group) is preferred. Examples of the alkyl group include the same ones as those explained as the substituent in X.

R ¹ is more preferably a hydrogen atom or a linear or branched C ₁ to C ₄ alkyl group which may have a substituent, and even more preferably a hydrogen atom or a linear or branched C ₁ to C ₃ alkyl group which may have a substituent.

When the aliphatic group of Z is interrupted by the bonding group, the number of bonding groups is not particularly limited, but may be about 1 to 10, preferably 1, 2 or 3, and more preferably 1 or 2. In addition, in the formula (1), it is preferable that the aliphatic group of Z is not interrupted by successive bonding groups. In other words, it is preferable that the bonding groups are not adjacent to each other. As the bonding group, at least one bonding group selected from the group consisting of -O-, -S-, -CO-, -CO-O-, -O-CO-, -NH-, -CO-NH-, -NH-CO-, -CO-O-NH-, -O-CO-NH- and -NH-CO-NH- is more preferable, and at least one bonding group selected from the group consisting of -O-, -S-, -CO-, -NH-, -CO-NH- and -NH-CO- is particularly preferable.

Examples of the substituent in Z include a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), a carboxyl group, a _C2 to _C6 linear or branched acyl group, a _C1 to _C6 linear or branched alkyl group, and a _C1 to _C6 linear or branched alkoxy group.

Specific examples of asymmetric acrylamide-methacrylic acid ester compounds (b-1) include, but are not limited to, those shown below.

Among these, from the viewpoints of adhesion to tooth tissue and polymerization hardening properties, asymmetric acrylamide-methacrylic acid ester compounds in which Z is a _C2 - _C4 linear or branched aliphatic group which may have a substituent are preferred, with N-methacryloyloxyethyl acrylamide (commonly known as "MAEA"), N-methacryloyloxypropyl acrylamide, N-methacryloyloxybutyl acrylamide, N-(1-ethyl-(2-methacryloyloxy)ethyl)acrylamide, and N-(2-(2-methacryloyloxyethoxy)ethyl)acrylamide being more preferred, and MAEA and N-methacryloyloxypropyl acrylamide being particularly preferred from the viewpoint of high hydrophilicity involved in penetration into the collagen layer of dentin.

The asymmetric acrylamide-methacrylic acid ester compound (b-1) may be used alone or in combination of two or more kinds. The content of the asymmetric acrylamide-methacrylic acid ester compound (b-1) is not particularly limited as long as the effects of the present invention are achieved, but is preferably 1 to 60 parts by mass, more preferably 2 to 45 parts by mass, even more preferably 3 to 30 parts by mass, and particularly preferably 5 to 25 parts by mass, per 100 parts by mass of the total amount of monomers in the self-adhesive dental composite resin (X) of the present invention.

Hydrophobic monomer (b-2) having no acidic group
The hydrophobic monomer (b-2) having no acidic group improves the handleability of the self-adhesive dental composite resin (X) and the mechanical strength of the cured product. As the hydrophobic monomer (b-2), a radical monomer having no acidic group and a polymerizable group is preferable, and from the viewpoint of easiness of radical polymerization, the polymerizable group is preferably a (meth)acrylic group and/or a (meth)acrylamide group. The hydrophobic monomer (b-2) means a monomer having no acidic group, not corresponding to the asymmetric acrylamide-methacrylic acid ester compound (b-1), and having a solubility in water at 25°C of less than 10% by mass. As the hydrophobic monomer (b-2), for example, a crosslinkable monomer such as a bifunctional monomer of an aromatic compound, a bifunctional monomer of an aliphatic compound, or a trifunctional or higher monomer can be mentioned.

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, phenyl)propane, 2,2-bis(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 is 2.6, commonly known as "D-2.6E"), 2,2-bis(4-(meth)acryloyloxydiethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxytriethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxytetraethoxyphenyl)propane, and 2,2-bis(4-(meth)acryloyloxypentaethoxyphenyl)propane are preferred.

Examples of aliphatic bifunctional monomers 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, 1,10-decanediol di(meth)acrylate, 1,2-bis(3-methacryloyloxy-2-hydroxypropoxy)ethane, and 2,2,4-trimethylhexamethylenebis(2-carbamoyloxyethyl)di(meth)acrylate. Among these, triethylene glycol diacrylate, triethylene glycol dimethacrylate (commonly known as "3G"), neopentyl glycol di(meth)acrylate, 1,2-bis(3-methacryloyloxy-2-hydroxypropoxy)ethane, 2,2,4-trimethylhexamethylene bis(2-carbamoyloxyethyl) dimethacrylate (commonly known as "UDMA"), 1,10-decanediol dimethacrylate (commonly known as "DD"), and 2,2,4-trimethylhexamethylene bis(2-carbamoyloxyethyl) dimethacrylate are preferred.

Examples of trifunctional or higher 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, 1,7-diacryloyloxy-2,2,6,6-tetra(meth)acryloyloxymethyl-4-oxaheptane, etc. Among these, N,N-(2,2,4-trimethylhexamethylene)bis[2-(aminocarboxy)propane-1,3-diol]tetramethacrylate is preferred.

Among the above hydrophobic monomers (b-2), from the viewpoint of mechanical strength and handling, bifunctional monomers of aromatic compounds and bifunctional monomers of aliphatic compounds are preferably used. Bis-GMA and D-2.6E are preferred as bifunctional monomers of aromatic compounds. Glycerol di(meth)acrylate, 3G, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, DD, 1,2-bis(3-methacryloyloxy-2-hydroxypropoxy)ethane, and UDMA are preferred as bifunctional monomers of aliphatic compounds.

Among the above hydrophobic monomers (b-2), Bis-GMA, D-2.6E, 3G, UDMA, and DD are more preferred, and D-2.6E, 3G, and Bis-GMA are even more preferred, from the viewpoint of good adhesion to tooth structure when used as a self-adhesive dental composite resin (X) (composition).

The hydrophobic monomer (b-2) may be used alone or in combination of two or more kinds. The content of the hydrophobic monomer (b-2) in the self-adhesive dental composite resin (X) of the present invention is preferably 20 to 98 parts by mass, more preferably 40 to 95 parts by mass, and even more preferably 60 to 92 parts by mass, per 100 parts by mass of the total amount of the monomers. When the content of the hydrophobic monomer (b-2) is equal to or less than the upper limit, the wettability of the self-adhesive dental composite resin (X) to the dentin is not reduced, and the desired adhesive strength is easily obtained. When the content is equal to or more than the lower limit, the desired mechanical strength of the cured product is easily obtained.

Hydrophilic monomer (b-3) having no acidic group
The self-adhesive dental composite resin (X) of the present invention preferably contains a hydrophilic monomer (b-3) that does not have an acidic group. The hydrophilic monomer (b-3) improves the wettability of the self-adhesive dental composite resin to the tooth structure. As the hydrophilic monomer (b-3), a radical monomer that does not have an acidic group and has a polymerizable group is preferable, and from the viewpoint of easy radical polymerization, the polymerizable group is preferably a (meth)acrylic group and/or a (meth)acrylamide group. The hydrophilic monomer (b-3) means a monomer that does not have an acidic group, does not correspond to the asymmetric acrylamide-methacrylic acid ester compound (b-1), and has a solubility in water at 25°C of 10% by mass or more, preferably a monomer that has a solubility of 30% by mass or more, and more preferably a monomer that can be dissolved in water at any ratio at 25°C. As the hydrophilic monomer, a monomer that has a hydrophilic group such as a hydroxyl group, an oxymethylene group, an oxyethylene group, an oxypropylene group, or an amide group is preferable. Examples of the hydrophilic monomer (b-3) include hydrophilic monofunctional (meth)acrylate monomers 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-((meth)acryloyloxy)ethyltrimethylammonium chloride, and polyethylene glycol di(meth)acrylate (having 9 or more oxyethylene groups); and monofunctional (meth)acrylamide monomers such as N-methylol(meth)acrylamide, N-hydroxyethyl(meth)acrylamide, N,N-bis(2-hydroxyethyl)(meth)acrylamide, N-methoxymethyl(meth)acrylamide, N-ethoxymethyl(meth)acrylamide, diacetone(meth)acrylamide, 4-(meth)acryloylmorpholine, N-trihydroxymethyl-N-methyl(meth)acrylamide, N,N-dimethylacrylamide, and N,N-diethylacrylamide.

Of these hydrophilic monomers (b-3), from the viewpoint of adhesion to tooth structure, 2-hydroxyethyl (meth)acrylate, 2,3-dihydroxypropyl (meth)acrylate, diacetone (meth)acrylamide and hydrophilic monofunctional (meth)acrylamide monomers are preferred, and 2-hydroxyethyl (meth)acrylate, N,N-dimethylacrylamide and N,N-diethylacrylamide are more preferred. One type of hydrophilic monomer (b-3) may be used alone, or two or more types may be used in combination.

The content of hydrophilic monomer (b-3) in the self-adhesive dental composite resin (X) of the present invention is preferably in the range of 0 to 50 parts by mass, more preferably 0 to 40 parts by mass, and even more preferably 0 to 30 parts by mass, per 100 parts by mass of the total amount of monomers. The content of hydrophilic monomer (b-3) may be 0 parts by mass per 100 parts by mass of the total amount of monomers. When the content of hydrophilic monomer (b-3) in the self-adhesive dental composite resin (X) of the present invention is equal to or greater than the lower limit, the adhesive strength is easily improved, and when the content is equal to or less than the upper limit, the desired mechanical strength of the cured product is easily obtained.

The content of the monomer (b) not having an acidic group in the self-adhesive dental composite resin (X) is preferably 60 to 99 parts by mass, more preferably 65 to 97.5 parts by mass, and even more preferably 70 to 95 parts by mass, per 100 parts by mass of the total amount of monomers. From the viewpoint of adhesion to tooth substance, the mass ratio ((b-2)):(b-3) of the hydrophobic monomer (b-2) to the hydrophilic monomer (b-3) is preferably 10:0 to 1:2, more preferably 10:0 to 1:1, and even more preferably 10:0 to 2:1.

A preferred embodiment is a self-adhesive dental composite resin (X) that is substantially free of difunctional or higher (meth)acrylamide monomers. Another preferred embodiment is a self-adhesive dental composite resin that is substantially free of a diester hydrogen phosphate group-containing monomer. The diester hydrogen phosphate group-containing monomer has a (meth)acryloyloxy group and/or a (meth)acrylamide group. In the present invention, substantially free of a polymerizable compound means that the content of the polymerizable compound is less than 0.5 parts by mass, preferably less than 0.1 parts by mass, more preferably less than 0.01 parts by mass, and may be 0 parts by mass, in 100 parts by mass of the total amount of monomers contained in the composition of the self-adhesive dental composite resin (X). The content of the polymerizable compound that is substantially free may be less than 0.5% by mass, or less than 0.1% by mass, in the entire composition.

<Polymerization initiator (c)>
The polymerization initiator (c) includes a photopolymerization initiator (c-1) or a chemical polymerization initiator (c-2), and one type of each may be blended alone or two or more types may be blended in combination.

The photopolymerization initiator (c-1) is classified into a water-soluble photopolymerization initiator (c-1a) and a water-insoluble photopolymerization initiator (c-1b). As the photopolymerization initiator (c-1), only the water-soluble photopolymerization initiator (c-1a) may be used, only the water-insoluble photopolymerization initiator (c-1b) may be used, or the water-insoluble photopolymerization initiator (c-1a) and the water-insoluble photopolymerization initiator (c-1b) may be used in combination, and it is preferable to use them in combination.

Water-soluble photopolymerization initiator (c-1a)
The water-soluble photopolymerization initiator (c-1a) improves polymerization curing at the hydrophilic tooth surface interface, and can realize high adhesive strength. The water-soluble photopolymerization initiator (c-1a) has a solubility in water at 25°C of 10 g/L or more, preferably 15 g/L or more, more preferably 20 g/L or more, and even more preferably 25 g/L or more. By having the solubility of 10 g/L or more, the water-soluble photopolymerization initiator (c-1a) is sufficiently dissolved in water in the tooth substance at the adhesive interface, and the polymerization promotion effect is easily exhibited.

Examples of the water-soluble photopolymerization initiator (c-1a) include water-soluble thioxanthones, water-soluble acylphosphine oxides, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one having a (poly)ethylene glycol chain introduced to a hydroxyl group, 1-hydroxycyclohexyl phenyl ketone having a (poly)ethylene glycol chain introduced to a hydroxyl group and/or a phenyl group, 1-hydroxycyclohexyl phenyl ketone having -OCH 2 COO ^- Na ⁺ introduced to a phenyl group, 2-hydroxy-2-methyl-1-phenylpropan-1-one having a (poly)ethylene glycol chain introduced to a hydroxyl group and/or a phenyl group, and ₂ -hydroxy-2-methyl-1-phenylpropan-1-one having -OCH ₂ COO ^- Na introduced to a phenyl group. ⁺ introduced; and α-aminoalkylphenones such as 2-methyl-1[4-(methylthio)phenyl]-2-morpholinopropan-1-one and 2-benzyl-2-(dimethylamino)-1-[(4-morpholino)phenyl]-1-butanone in which the amino group is converted into a quaternary ammonium salt.

Examples of the water-soluble thioxanthones include 2-hydroxy-3-(9-oxo-9H-thioxanthen-4-yloxy)-N,N,N-trimethyl-1-propanaminium chloride, 2-hydroxy-3-(1-methyl-9-oxo-9H-thioxanthen-4-yloxy)-N,N,N-trimethyl-1-propanaminium chloride, 2-hydroxy-3-(9-oxo-9H-thioxanthen-2-yloxy)-N,N,N-trimethyl-1-propanaminium 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, etc. can be used.

Examples of the water-soluble acylphosphine oxides include acylphosphine oxides represented by the following general formula (2) or (3).

In formulas (2) and (3), R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , and R ⁷ are each independently a C ₁ to C ₄ linear or branched alkyl group or a halogen atom; M is a hydrogen ion, an alkali metal ion, an alkaline earth metal ion, a magnesium ion, a pyridinium ion (the pyridine ring may have a substituent), or an ammonium ion represented by HN ⁺ R ⁹ R ¹⁰ R ¹¹ (wherein R ⁹ , R ¹⁰ , and R ¹¹ are each independently an organic group or a hydrogen atom); n is 1 or 2; X is a C ₁ to C ₄ linear or branched alkylene group; R ⁸ is represented by —CH(CH ₃ )COO(C ₂ H ₄ O) _p CH ₃ , where p is an integer from 1 to 1,000.

The alkyl group of R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , and R ⁷ is not particularly limited as long as it is a linear or branched C ₁ to C ₄ group, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a 2-methylpropyl group, and a tert-butyl group. The alkyl group of R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , and R ⁷ is preferably a linear C ₁ to C ₃ alkyl group, more preferably a methyl group or an ethyl group, and even more preferably a methyl group. X is preferably a methylene group, an ethylene group, an n-propylene group, an isopropylene group, and an n-butylene group. X is preferably a linear C ₁ to C ₃ alkyl group, more preferably a methylene group or an ethylene group, and even more preferably a methylene group.

When M is a pyridinium ion, examples of the substituent on the pyridine ring include halogen atoms (fluorine, chlorine, bromine, and iodine atoms), carboxyl groups, _C2 - _C6 linear or branched acyl groups, _C1 - _C6 linear or branched alkyl groups, and _C1 - _C6 linear or branched alkoxy groups. M is preferably an alkali metal ion, an alkaline earth metal ion, a magnesium ion, a pyridinium ion (the pyridine ring may have a substituent), or an ammonium ion represented by HN ^{+ R9R10R11} (wherein the symbols have the same meanings as above). Examples of the alkali metal ion include a lithium ion, a sodium ion ^, a ^potassium ion, a rubidium ion, and a cesium ion. Examples of the alkaline earth metal ion include a calcium ion, a strontium ion, a barium ion, and a radium ion. The organic groups of R ⁹ , R ¹⁰ and R ¹¹ include the same groups as the substituents of the pyridine ring (excluding halogen atoms).

Among these, a compound in which R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , and R ⁷ are all methyl groups is particularly preferred in terms of storage stability and color stability in the composition of the self-adhesive dental composite resin (X). Examples of the ammonium ion include ammonium ions derived from various amines. Examples of the amine include ammonia, trimethylamine, diethylamine, dimethylaniline, ethylenediamine, triethanolamine, N,N-dimethylamino methacrylate, 4-(N,N-dimethylamino)benzoic acid and its alkyl esters, 4-(N,N-diethylamino)benzoic acid and its alkyl esters, and N,N-bis(2-hydroxyethyl)-p-toluidine.

For ^R8 , from the viewpoint of adhesiveness, p is preferably 1 or more, more preferably 2 or more, even more preferably 3 or more, and particularly preferably 4 or more; it is preferably 1,000 or less, more preferably 100 or less, even more preferably 75 or less, and particularly preferably 50 or less.

Among these water-soluble acylphosphine oxides, a compound represented by general formula (2) in which Mn ⁺ is a lithium ion, and a compound represented by general formula (3) synthesized from polyethylene glycol methyl ether methacrylate in which the portion corresponding to the group represented by ^R8 has a molecular weight of 950 are particularly preferred.

Water-soluble acylphosphine oxides having such a structure can be synthesized according to known methods, and some are also available as commercially available products. For example, they can be synthesized by the methods disclosed in JP-A-57-197289 or WO 2014/095724. The water-soluble photopolymerization initiator (c-1a) may be used alone or in combination of two or more types.

The water-soluble photopolymerization initiator (c-1a) may be dissolved in the self-adhesive dental composite resin (X) or may be dispersed in powder form in the composition of the self-adhesive dental composite resin (X).

When dispersing the water-soluble photopolymerization initiator (c-1a) in powder form, if the average particle size is too large, it will tend to settle, so it is preferably 500 μm or less, more preferably 100 μm or less, and even more preferably 50 μm or less. On the other hand, if the average particle size is too small, the specific surface area of the powder will be too large, reducing the amount of the self-adhesive dental composite resin (X) that can be dispersed in the composition, so it is preferably 0.01 μm or more. In other words, the average particle size of the water-soluble photopolymerization initiator (c-1a) is preferably in the range of 0.01 to 500 μm, more preferably in the range of 0.01 to 100 μm, and even more preferably in the range of 0.01 to 50 μm.

The average particle size of each water-soluble photopolymerization initiator (c-1a) powder can be calculated as the volume average particle size after performing image analysis using image analysis particle size distribution measurement software (Mac-View; manufactured by Mountec Co., Ltd.) based on electron micrographs of 100 or more particles.

When the water-soluble photopolymerization initiator (c-1a) is dispersed in powder form, various shapes such as spherical, needle-like, plate-like, and crushed shapes can be used, but there is no particular limitation. The water-soluble photopolymerization initiator (c-1a) can be prepared by conventional methods such as a pulverization method, a freeze-drying method, and a reprecipitation method. From the viewpoint of the average particle size of the obtained powder, the freeze-drying method and the reprecipitation method are preferred, and the freeze-drying method is more preferred.

From the viewpoint of the curing property of the obtained self-adhesive dental composite resin (X), the content of the water-soluble photopolymerization initiator (c-1a) is preferably 0.01 to 20 parts by mass relative to 100 parts by mass of the total amount of the monomers in the self-adhesive dental composite resin (X) of the present invention, and from the viewpoint of the adhesive strength to the tooth substance, 0.05 to 10 parts by mass is more preferable, and 0.1 to 5 parts by mass is even more preferable. When the content of the water-soluble photopolymerization initiator (c-1a) is equal to or more than the lower limit, polymerization at the adhesive interface proceeds sufficiently, and sufficient adhesive strength is likely to be obtained. On the other hand, when the content of the water-soluble photopolymerization initiator (c-1a) is equal to or less than the upper limit, sufficient adhesive strength is likely to be obtained.

Non-water-soluble photopolymerization initiator (c-1b)
From the viewpoint of curing property, the self-adhesive dental composite resin (X) of the present invention preferably contains, in addition to the water-soluble photopolymerization initiator (c-1a), a water-insoluble photopolymerization initiator (c-1b) having a solubility in water at 25°C of less than 10 g/L (hereinafter, may be referred to as water-insoluble photopolymerization initiator (c-1b)). The water-insoluble photopolymerization initiator (c-1b) used in the present invention may be a known photopolymerization initiator. The water-insoluble photopolymerization initiator (c-1b) may be used alone or in combination of two or more kinds.

Examples of the non-water-soluble photopolymerization initiator (c-1b) include (bis)acylphosphine oxides, thioxanthones, ketals, α-diketones, coumarins, anthraquinones, benzoin alkyl ether compounds, and α-aminoketone compounds other than the water-soluble photopolymerization initiator (c-1a).

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. Examples of 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(2,5,6-trimethylbenzoyl)-2,4,4-trimethylpentylphosphine oxide.

Examples of the thioxanthones include thioxanthone and 2-chlorothioxanthen-9-one.

Examples of the ketals include benzyl dimethyl ketal and benzyl diethyl ketal.

Examples of the α-diketones include diacetyl, benzil, dl-camphorquinone, 2,3-pentadione, 2,3-octadione, 9,10-phenanthrenequinone, 4,4'-oxybenzil, and acenaphthenequinone. Among these, dl-camphorquinone is particularly preferred because it has a maximum absorption wavelength in the visible light region.

Examples of the coumarins include 3,3'-carbonylbis(7-diethylaminocoumarin), 3-(4-methoxybenzoyl)coumarin, 3-thienoylcoumarin, 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-bromocoumarin, 3,3'-carbonylbiscoumarin, 3-benzoyl-7-dimethylaminocoumarin, 3-benzoylbenzo[f]coumarin, and 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, 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-difluorobenzoyl)benzo[f]coumarin, 3-[(1-methylnaphtho[1,2-d]thiazol-2-ylidene)acetyl]coumarin, 3,3'-carbonylbis(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 Examples of compounds include those described in JP-A-9-3109 and JP-A-10-245525, such as 3,3'-carbonylbis(7-dibutylaminocoumarin), 3,3'-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.

Among the above-mentioned coumarins, 3,3'-carbonylbis(7-diethylaminocoumarin) and 3,3'-carbonylbis(7-dibutylaminocoumarin) are particularly preferred.

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

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

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

Among these non-water-soluble photopolymerization initiators (c-1b), it is preferable to use at least one selected from the group consisting of (bis)acylphosphine oxides, α-diketones, and coumarins. This results in a self-adhesive dental composite resin (X) that has excellent photocuring properties in the visible and near-ultraviolet regions and exhibits sufficient photocuring properties whether a halogen lamp, a light-emitting diode (LED), or a xenon lamp is used as a light source.

The content of the water-insoluble photopolymerization initiator (c-1b) is not particularly limited, but from the viewpoint of the curing property of the composition of the self-adhesive dental composite resin (X) obtained, it is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 7 parts by mass, and even more preferably 0.1 to 5 parts by mass, relative to 100 parts by mass of the total amount of monomers in the self-adhesive dental composite resin (X) of the present invention. In addition, by having the content of the water-insoluble photopolymerization initiator (c-1b) be equal to or less than the upper limit, sufficient adhesive strength is easily obtained even when the polymerization performance of the water-insoluble photopolymerization initiator (c-1b) itself is low, and further, precipitation of the water-insoluble photopolymerization initiator (c-1b) itself from the self-adhesive dental composite resin (X) can be suppressed.

When the water-soluble photopolymerization initiator (c-1a) and the water-insoluble photopolymerization initiator (c-1b) are used in combination, the mass ratio of the water-soluble photopolymerization initiator (c-1a) to the water-insoluble photopolymerization initiator (c-1b) in the present invention [(c-1a):(c-1b)] is preferably 10:1 to 1:10, more preferably 7:1 to 1:7, even more preferably 5:1 to 1:5, and particularly preferably 3:1 to 1:3. If the water-soluble photopolymerization initiator (c-1a) is contained in a mass ratio of more than 10:1, the curing property of the self-adhesive dental composite resin (X) itself may decrease, making it difficult to develop high adhesive strength. On the other hand, if the water-insoluble photopolymerization initiator (c-1b) is contained in a mass ratio of more than 1:10, the curing property of the self-adhesive dental composite resin (X) itself may be increased, but the polymerization promotion at the adhesive interface may be insufficient, making it difficult to develop high adhesive strength.

Chemical polymerization initiator (c-2)
The self-adhesive dental composite resin (X) of the present invention may further contain a chemical polymerization initiator, and an organic peroxide is preferably used. The organic peroxide used as the above-mentioned chemical polymerization initiator is not particularly limited, and known organic peroxides can be used. Representative organic peroxides include, for example, ketone peroxides, hydroperoxides, diacyl peroxides, dialkyl peroxides, peroxyketals, peroxyesters, and peroxydicarbonates. Specific examples of these organic peroxides include those described in International Publication No. 2008/087977. The chemical polymerization initiator (c-2) may be used alone or in combination of two or more kinds.

<Filler (d)>
The self-adhesive dental composite resin (X) of the present invention contains a filler (d) in order to adjust the handling property and to increase the mechanical strength of the cured product. Examples of such fillers include inorganic fillers (d-1), organic-inorganic composite fillers (d-2), and organic fillers (d-3). The filler (d) may be used alone or in combination of two or more kinds.

Examples of the material of the inorganic filler (d-1) 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, ytterbium oxide, silica-coated ytterbium fluoride, etc. In a preferred embodiment, a dental restoration kit is provided that includes a self-adhesive dental composite resin (X) in which the filler (d) contains the inorganic filler (d-1). The inorganic filler (d-1) may be used alone or in combination of two or more types.

Among the inorganic fillers (d-1), in terms of the transparency and mechanical strength of the resulting self-adhesive dental composite resin (X), quartz, silica, silica-zirconia, barium glass, ytterbium oxide, and silica-coated ytterbium fluoride are preferred, and quartz, silica, silica-zirconia, barium glass, and silica-coated ytterbium fluoride are more preferred. A combination of at least one selected from the group consisting of quartz, silica, silica-zirconia, and barium glass with silica-coated ytterbium fluoride is even more preferred, and a combination of quartz and silica-coated ytterbium fluoride is particularly preferred. When using these inorganic fillers, the transparency can be appropriately adjusted by adjusting the difference between the refractive index of the polymerizable monomer (polymerizable monomer mixture in the case of two or more monomers) consisting of the monomer (a) having an acidic group and the monomer (b) not having an acidic group and the refractive index of the inorganic filler.

From the viewpoint of the handleability and mechanical strength of the resulting self-adhesive dental composite resin (X), the average particle diameter of the inorganic filler (d-1) is preferably 0.001 to 50 μm, and more preferably 0.001 to 10 μm. In the present invention, when the inorganic filler (d-1) is surface-treated as described below, the average particle diameter of the inorganic filler (d-1) means the average particle diameter before the surface treatment.

In one preferred embodiment, the filler (d) includes an inorganic filler (d-1), and in order to enhance the shielding properties against blackening caused by an aqueous solution (Y) containing diamine silver fluoride, the filler (d) includes, in addition to the inorganic filler (d-1), an inorganic filler (d-1a) having a refractive index of 1.9 or more (hereinafter, sometimes simply referred to as "inorganic filler (d-1a)"). The inorganic filler (d-1) excludes the inorganic filler (d-1a). The refractive index of the inorganic filler (d-1a) is 1.9 or more, and from the viewpoints of aesthetics and surface hardening, it is preferably 2.0 or more, and more preferably 2.1 or more. Examples of the inorganic filler (d-1a) include titanium oxide (refractive index: 2.49 to 2.90), zirconium oxide (refractive index: 2.13 to 2.19), and zinc oxide (refractive index: 2.00 to 2.02). In this specification, the refractive index of the inorganic filler (d-1) and the monomer component can be measured with an Abbe refractometer. The refractive index of the inorganic filler (d-1) can be measured by partially modifying JIS K 0062:1992. Specifically, the refractive index can be measured by an immersion method at 23°C using an Abbe refractometer and sodium D line as a light source. As the liquid used in the immersion method, a plurality of liquids having different refractive indices are prepared by combining two or more liquids having refractive indices close to the expected refractive index of the filler of the sample. The sample is suspended in each liquid under a 23°C atmosphere, and the liquid that appears most transparent when observed with the naked eye is selected. The refractive index of the liquid is taken as the refractive index of the sample, and the refractive index of the liquid is measured with an Abbe refractometer. Examples of liquids that can be used (intermediate liquids) include diiodomethane in which sulfur is dissolved, 1-bromonaphthalene, methyl salicylate, dimethylformamide, 1-pentanol, etc. In the case of a monomer component (polymerizable monomer mixture when two or more types of monomers are used), it can be measured in accordance with JIS K 0062:1992, specifically, using an Abbe refractometer with sodium D line as a light source in an atmosphere of 23°C. In the case of a monomer component before curing, it can be measured in liquid form. In the case of a monomer component after curing (cured product of a polymerizable monomer mixture when two or more types of monomers are used), the monomer component is made into a cured plate of a certain size and measured. Usable liquids include diiodomethane with sulfur dissolved therein, 1-bromonaphthalene, methyl salicylate, dimethylformamide, 1-pentanol, etc.

The inorganic filler (d-1a) may be used alone or in combination of two or more kinds. The content of the inorganic filler (d-1a) is preferably 0.001 parts by mass or more, more preferably 0.01 parts by mass or more, and even more preferably 0.1 parts by mass or more, per 100 parts by mass of the total amount of the self-adhesive dental composite resin (X). There is no particular upper limit to the content of the inorganic filler (d-1a), but if too much is added, the aesthetics of the self-adhesive dental composite resin (X) may be reduced, so it is preferable to add it appropriately in the range of 1 part by mass or less.

From the viewpoint of the shielding properties and handling properties of the resulting self-adhesive dental composite resin (X), the average particle size of the inorganic filler (d-1a) is preferably 0.01 to 10 μm, and more preferably 0.05 to 5 μm.

The shape of the inorganic filler (d-1) is not particularly limited, and the particle size of the filler can be appropriately selected and used, and examples thereof include amorphous fillers and spherical fillers. From the viewpoint of improving the mechanical strength of the cured product of the self-adhesive dental composite resin (X), it is preferable to use a spherical filler as the inorganic filler. Here, the spherical filler is a filler in which the particles observed within a unit field of view of a photograph of the filler taken with an electron microscope are rounded, and the average uniformity obtained by dividing the particle diameter in a direction perpendicular to the maximum diameter by the maximum diameter is 0.6 or more. The average particle diameter of the spherical filler is preferably 0.05 to 5 μm. By having an average particle diameter equal to or greater than the lower limit, it is easy to obtain a sufficient filling rate of the spherical filler in the self-adhesive dental composite resin (X), and it is easy to obtain the desired mechanical strength. On the other hand, by having an average particle size equal to or less than the upper limit, the surface area of the spherical filler is less likely to decrease, making it easier to obtain a cured product of the self-adhesive dental composite resin (X) that has the desired mechanical strength.

In order to adjust the fluidity of the self-adhesive dental composite resin, the inorganic filler (d-1) may be surface-treated with a known surface treatment agent such as a silane coupling agent before use, if necessary. For example, by surface-treating the hydroxyl groups present on the surface of the inorganic filler with a silane coupling agent, an inorganic filler with the hydroxyl groups surface-treated can be obtained. Examples of surface treatment agents include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrichlorosilane, vinyltri(β-methoxyethoxy)silane, γ-methacryloyloxypropyltrimethoxysilane, 8-methacryloyloxyoctyltrimethoxysilane, 11-methacryloyloxyundecyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, and γ-aminopropyltriethoxysilane.

As the surface treatment method, any known method can be used without any particular limitation. For example, there is a method of spraying the above-mentioned surface treatment agent while vigorously stirring the inorganic filler, a method of dispersing or dissolving the inorganic filler and the above-mentioned surface treatment agent in a suitable solvent and then removing the solvent, or a method of hydrolyzing the alkoxy groups of the above-mentioned surface treatment agent in an aqueous solution with an acid catalyst to convert them to silanol groups, attaching them to the inorganic filler surface in the aqueous solution, and then removing the water. In any of these methods, the reaction between the inorganic filler surface and the above-mentioned surface treatment agent can be completed by heating in the range of 50 to 150°C, and the surface treatment can be performed. The amount of surface treatment is not particularly limited, and for example, 1 to 10 parts by mass of the surface treatment agent can be used per 100 parts by mass of the inorganic filler before treatment.

The organic-inorganic composite filler (d-2) used in the present invention is obtained by adding a monomer to the inorganic filler (d-1) described above in advance, forming a paste, polymerizing it, and pulverizing it. The organic-inorganic composite filler (d-2) refers to a filler containing the inorganic filler (d-1) and a polymer of a polymerizable monomer. As the organic-inorganic composite filler (d-2), for example, TMPT filler (trimethylolpropane methacrylate and silica filler are mixed, polymerized, and then pulverized) can be used. The shape of the organic-inorganic composite filler (d-2) is not particularly limited, and the particle size of the filler can be appropriately selected and used. From the viewpoint of the handleability and mechanical strength of the obtained self-adhesive dental composite resin (X) composition, the average particle size of the organic-inorganic composite filler (d-2) is preferably 0.001 to 50 μm, more preferably 0.001 to 10 μm.

Examples of the organic filler (d-3) 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, acrylonitrile-styrene-butadiene copolymer, etc., and the organic filler (d-3) may be used alone or in a mixture of two or more kinds. The shape of the organic filler (d-3) is not particularly limited, and the particle size of the filler can be appropriately selected and used. From the viewpoint of the handleability and mechanical strength of the obtained self-adhesive dental composite resin (X), the average particle size of the organic filler (d-3) is preferably 0.001 to 50 μm, more preferably 0.001 to 10 μm.

In this specification, the average particle size of the filler (d) can be determined by a laser diffraction scattering method or by observing the particles under an electron microscope. Specifically, the laser diffraction scattering method is convenient for measuring the particle size of particles of 0.1 μm or more, while the electron microscope observation is convenient for measuring the particle size of ultrafine particles of less than 0.1 μm. 0.1 μm is a value measured by the laser diffraction scattering method.

Specifically, the laser diffraction scattering method can be performed, for example, by using a laser diffraction particle size distribution analyzer (SALD-2300: manufactured by Shimadzu Corporation) and measuring on a volume basis using a 0.2% aqueous solution of sodium hexametaphosphate as the dispersion medium.

Specific examples of electron microscope observations include taking a photograph of the particles with an electron microscope (S-4000 model, manufactured by Hitachi, Ltd.) and measuring the particle diameters of the particles (200 or more) observed within a unit field of view of the photograph using image analysis particle size distribution measurement software (Mac-View (manufactured by Mountec Co., Ltd.)). In this case, the particle diameter is found as the arithmetic mean value of the longest and shortest lengths of the particles, and the average primary particle diameter is calculated from the number of particles and their particle diameters.

The self-adhesive dental composite resin (X) of the present invention preferably uses a mixture or combination of two or more fillers having different materials, particle size distributions, and shapes. By combining two or more fillers, the fillers are densely packed and the number of interaction points between the fillers and the monomers or between the fillers themselves increases. In addition, depending on the type of filler, it is possible to control the fluidity of the paste depending on the presence or absence of shear force. In particular, from the viewpoint of the handleability and paste properties of the self-adhesive dental composite resin (X) of the present invention, the filler (d) is preferably a combination (I) of a filler (d-i) having an average particle size of 1 nm or more and less than 0.1 μm and a filler (d-ii) having an average particle size of 0.1 μm or more and 1 μm or less, a combination (II) of a filler (d-i) having an average particle size of 1 nm or more and less than 0.1 μm and a filler (d-iii) having an average particle size of more than 1 μm and 10 μm or less, a combination (III) of a filler (d) having an average particle size of 1 nm or more and less than 0.1 μm and a filler (d-iii) having an average particle size of 1 nm or more and 10 μm or less, or a combination (IV) of a filler (d) having an average particle size of 1 nm or more and less than 0.1 μm and a filler (d-iii) having an average particle size of 1 nm or more and less than 10 μm. A combination (III) of a filler (d-i) of less than 0.1 μm with a filler (d-ii) having an average particle size of 0.1 μm or more and 1 μm or less, or a filler (d-iii) having an average particle size of more than 1 μm and 10 μm or less, and a combination (IV) of fillers (d-ii) having an average particle size of 0.1 μm or more and 1 μm or less are preferred, and among these combinations, (I), (II), and (III) are more preferred, and (I) and (II) are even more preferred, from the viewpoint of paste properties and cavity sealing properties. The combination (IV) of fillers (d-ii) having an average particle size of 0.1 μm or more and 1 μm or less means an embodiment including two types of fillers (d-ii) having different average particle sizes of 0.1 μm or more and 1 μm or less. Note that, as long as it is the above combination, different types of fillers may be included in the fillers (d) of each particle size. In addition, particles other than the filler may be unintentionally included as impurities within a range that does not impair the effects of the present invention.

The content of the filler (d) is not particularly limited, but from the viewpoint of the mechanical strength of the cured product and adhesion to tooth structure, it is preferably 50 parts by mass or more, more preferably 50 to 90 parts by mass, even more preferably 55 to 85 parts by mass, and particularly preferably 60 to 80 parts by mass, per 100 parts by mass of the total amount of the self-adhesive dental composite resin (X).

The material type of the self-adhesive dental composite resin (X) of the present invention is not particularly limited, and may be, for example, a two-paste type, but from the viewpoint of ease of use, it is preferable that it is a one-material type (one-paste type) in which all components are premixed.

The method for producing the self-adhesive dental composite resin (X) of the present invention is not particularly limited, and the resin can be easily produced by a method known to those skilled in the art (e.g., by mixing the necessary components).

<Polymerization accelerator (f)>
The self-adhesive dental composite resin (X) of the present invention can use a polymerization accelerator (f) together with the polymerization initiator (c). Examples of the polymerization accelerator (f) used in the present invention include amines, sulfinic acid and its 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.

Amines used as the polymerization accelerator (f) are divided into aliphatic amines and aromatic amines. Examples of 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, N-n-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, aliphatic tertiary amines are preferred from the viewpoint of the curing property and storage stability of the self-adhesive dental composite resin (X), and among these, N-methyldiethanolamine and triethanolamine are more preferred.

Examples of aromatic amines include N,N-bis(2-hydroxyethyl)-3,5-dimethylaniline, N,N-bis(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,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, 4-(N,N-dimethylamino)ethyl benzoate, 4-(N,N-dimethylamino)methyl benzoate, 4-(N,N-dimethylamino)propyl benzoate, 4-(N,N-dimethylamino)n-butoxyethyl benzoate, 4-(N,N-dimethylamino)2-(methacryloyloxy)ethyl benzoate, 4-(N,N-dimethylamino)benzophenone, and 4-(N,N-dimethylamino)butyl benzoate. Among these, from the viewpoint of imparting excellent curing properties to the self-adhesive dental composite resin (X), at least one selected from the group consisting of N,N-bis(2-hydroxyethyl)-p-toluidine, 4-(N,N-dimethylamino)ethyl benzoate, 4-(N,N-dimethylamino)n-butoxyethyl benzoate, and 4-(N,N-dimethylamino)benzophenone is preferred.

Specific examples of sulfinic acid and its 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 include those described in WO 2008/087977.

The polymerization accelerator (f) may be contained alone or in combination of two or more kinds. The content of the polymerization accelerator (f) used in the present invention is not particularly limited, but from the viewpoint of the curing property of the obtained self-adhesive dental composite resin (X), it is preferably 0.001 to 30 parts by mass, more preferably 0.01 to 10 parts by mass, and even more preferably 0.1 to 5 parts by mass, relative to 100 parts by mass of the total amount of the monomers in the self-adhesive dental composite resin (X). When the content of the polymerization accelerator (f) is equal to or more than the lower limit, polymerization proceeds sufficiently and sufficient adhesive strength is easily obtained, and it is more preferably 0.05 parts by mass or more. On the other hand, when the content of the polymerization accelerator (f) is equal to or less than the upper limit, it is easier to obtain sufficient adhesiveness and furthermore, precipitation of the polymerization accelerator (f) itself from the self-adhesive dental composite resin (X) can be suppressed, so it is more preferably 20 parts by mass or less.

<Fluoride ion releasing substances>
The self-adhesive dental composite resin (X) of the present invention may further contain a fluoride ion-releasing substance. By containing a fluoride ion-releasing substance, a self-adhesive dental composite resin (X) capable of imparting acid resistance to tooth structure can be obtained. Examples of such a fluoride ion-releasing substance include metal fluorides such as sodium fluoride, potassium fluoride, sodium monofluorophosphate, lithium fluoride, and ytterbium fluoride. The above fluoride ion-releasing substance may be contained alone or in combination of two or more kinds.

The self-adhesive dental composite resin (X) of the present invention may contain known additives within a range that does not impair performance. Examples of such additives include polymerization inhibitors, antioxidants, pigments, dyes, ultraviolet absorbers, solvents such as organic solvents, thickeners, etc. Additives may be used alone or in combination of two or more. In one embodiment, the content of the solvent (e.g., water, organic solvent) in the self-adhesive dental composite resin (X) is preferably less than 1 mass%, more preferably less than 0.1 mass%, and even more preferably less than 0.01 mass%, based on the total mass of the self-adhesive dental composite resin (X).

Examples of polymerization inhibitors include hydroquinone, hydroquinone monomethyl ether, dibutyl hydroquinone, dibutyl hydroquinone monomethyl ether, t-butyl catechol, 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 is preferably 0.001 to 1.0 part by mass per 100 parts by mass of the total amount of monomers of the self-adhesive dental composite resin (X).

The transparency (ΔL*) of the cured product of the self-adhesive dental composite resin (X) is 25 or less, but from the viewpoint of maintaining the clinical effects of diamine silver fluoride (e.g., prevention of dental caries, inhibition of the progression of dental caries, inhibition of dentin hypersensitivity, etc.) and further shielding discoloration caused by the aqueous solution (Y) containing diamine silver fluoride (e), it is preferably 22 or less, more preferably 20 or less, and even more preferably 15 or less. The method for measuring the transparency (ΔL*) of the cured product is as described in the Examples below. In order to make the transparency (ΔL*) of the cured product of the self-adhesive dental composite resin (X) 25 or less, it can be adjusted by the difference between the refractive index of the filler (d) and the refractive index of the polymerizable monomer consisting of the monomer (a) having an acidic group and the monomer (b) not having an acidic group, and the mixing ratio thereof. In addition, the transparency (ΔL*) of the cured product of the self-adhesive dental composite resin (X) can also be adjusted by combining the transparency of the filler (d) itself, such as by selecting a filler (d) that has a low transparency. In general, the refractive index of the cured product of a polymerizable monomer mixture that combines a monomer (a) having an acidic group and a monomer (b) that does not have an acidic group mainly depends on the blending ratio of aromatic compound-based polymerizable monomers (a mixture of aromatic compound-based polymerizable monomers when there are two or more kinds of aromatic compound-based polymerizable monomers) contained in the entire polymerizable monomer. Therefore, for example, when the self-adhesive dental composite resin (X) contains Bis-GMA and/or D-2.6E as an aromatic compound-based bifunctional monomer, the blending ratio of Bis-GMA and/or D-2.6E in the entire polymerizable monomer can be appropriately adjusted according to the refractive index of the filler (d) used and the transparency of the filler (d) itself.

An example of a suitable composition ratio in the self-adhesive dental composite resin (X) of the dental restoration kit of the present invention is shown below. When the total amount of monomers is 100 parts by mass, it is preferable that the total amount of monomers, 1 to 40 parts by mass of monomer (a) having an acidic group and 60 to 99 parts by mass of monomer (b) not having an acidic group are contained in the total amount of monomers of 100 parts by mass, and that the total amount of monomers, 100 parts by mass, contains 0.05 to 10 parts by mass of photopolymerization initiator (c-1), 100 to 900 parts by mass of filler (d), and 0.001 to 30 parts by mass of polymerization accelerator (f), and that the total amount of monomers, 100 parts by mass, contains 2.5 to 35 parts by mass of monomer (a) having an acidic group and 65 to 97.5 parts by mass of monomer (b) not having an acidic group, It is more preferable that the total amount of monomers is 100 parts by mass, and that the photopolymerization initiator (c-1) is 0.1 to 5 parts by mass, the filler (d) is 120 to 560 parts by mass, and the polymerization accelerator (f) is 0.01 to 10 parts by mass. It is even more preferable that the total amount of monomers is 100 parts by mass, and that the total amount of monomers is 100 parts by mass, and that the photopolymerization initiator (c-1) is 0.15 to 2.5 parts by mass, the filler (d) is 150 to 400 parts by mass, and the polymerization accelerator (f) is 0.1 to 5 parts by mass.

The concentration of the aqueous solution (Y) containing diamine silver fluoride (e) is not particularly limited as long as it is an aqueous solution containing diamine silver fluoride (e). From the viewpoint of the effects of inhibiting the progression of early caries, inhibiting secondary caries, and inhibiting dentin hypersensitivity (dentin dulling), an aqueous solution of 1 w/v% or more is preferable, and from the viewpoint of the effects of inhibiting the progression of early caries, inhibiting secondary caries, and inhibiting dentin hypersensitivity (dentin dulling), an aqueous solution of diamine silver fluoride with a concentration of 20 w/v% or more is more preferable, an aqueous solution of 30 w/v% or more is even more preferable, and an aqueous solution of 35 w/v% or more is particularly preferable. A commercially available product can be used as the aqueous solution (Y) containing diamine silver fluoride (e). As commercially available products, a 3.8 w/v% aqueous solution containing 38 mg of diamine silver fluoride in 1 ml of water and a 38 w/v% aqueous solution containing 380 mg of diamine silver fluoride in 1 ml of water are particularly preferable. These are sold under the trade names "Saffolide RC Liquid for Dental Use 3.8%" and "Saffolide Liquid for Dental Use 38%" (manufactured by Toyo Pharmaceutical Co., Ltd.). From the viewpoint of the action of an aqueous solution containing diamine silver fluoride (e), a 38% aqueous solution containing 380 mg of diamine silver fluoride in 1 ml of water is most preferable.

There are no particular limitations on the method of application of the aqueous solution (Y) containing diamine silver fluoride (e), but typically a few drops (0.15-0.20 ml) are soaked in a small cotton ball or similar, applied to the tooth structure, and left for 3-4 minutes. After application, the tooth is washed with water or dilute saline solution.

The aqueous solution (Y) containing diamine silver fluoride (e) may contain known additives within the range that does not impair performance. Examples of such additives include antioxidants, pigments, dyes, ultraviolet absorbers, organic solvents, thickeners, etc. One type of additive may be used alone, or two or more types may be used in combination. In order to exert the effects of diamine silver fluoride (e), the aqueous solution (Y) may not contain the monomer (a) having an acidic group, the monomer (b) not having an acidic group, the polymerization initiator (c), the filler (d), and the polymerization accelerator (f).

The dental restoration kit of the present invention can be used for treating dental caries (e.g., inhibiting the progression of early caries, inhibiting secondary caries, and treating root canals) and treating dentin hypersensitivity. In particular, for treating dental caries, the dental restoration kit of the present invention can be suitably used for a treatment called shield restoration, in which dentin softened by caries is sealed without being removed, because the silver component exhibits a sufficient penetration depth into softened dentin.

The present invention includes embodiments that combine the above configurations in various ways within the scope of the technical concept of the present invention, as long as the effects of the present invention are achieved.

The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. Note that parts in the examples are parts by weight unless otherwise specified.

Next, the components of the dental restoration kits in the examples and comparative examples are listed below along with their abbreviations.

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

[Monomer (b) having no acidic group]
Asymmetric acrylamide-methacrylate compound (b-1)
MAEA: N-methacryloyloxyethylacrylamide. Hydrophobic monomer not having an acidic group (b-2)
Bis-GMA: 2,2-bis[4-(3-methacryloyloxy-2-hydroxypropoxy)phenyl]propane D-2.6E: 2,2-bis(4-methacryloyloxypolyethoxyphenyl)propane (average number of moles of ethoxy groups added: 2.6)
3G: Triethylene glycol dimethacrylate

[Photopolymerization initiator (c-1)]
Non-water-soluble photopolymerization initiator (c-1b)
CQ: Camphorquinone

[Filler (d)]
Filler (d-1)
Filler 1: ultrafine silica "Aerosil (registered trademark) R 972" manufactured by Nippon Aerosil Co., Ltd., average particle size: 16 nm, refractive index: 1.46

Filler 2: Silane-treated silica powder Silica powder (manufactured by Nichitsu Co., Ltd., product name: Hi-Silica, refractive index: 1.55) was pulverized in a ball mill to obtain pulverized silica powder. The average particle size of the obtained pulverized silica powder was measured on a volume basis using a laser diffraction particle size distribution measuring device (manufactured by Shimadzu Corporation, model "SALD-2300") and found to be 2.2 μm. 100 parts by mass of this pulverized silica powder was surface-treated with 4 parts by mass of γ-methacryloyloxypropyltrimethoxysilane by a conventional method to obtain silane-treated silica powder.

Filler 3: 100 g of silane-treated barium glass powder GM27884 NF180 grade (barium glass manufactured by SCHOTT, average particle size: 0.18 μm, refractive index: 1.53), 13 g of γ-methacryloyloxypropyltrimethoxysilane, and 200 mL of 0.3 mass% acetic acid aqueous solution were placed in a three-necked flask and stirred at room temperature for 2 hours. After removing water by freeze-drying, heat treatment was performed at 80 ° C. for 5 hours to obtain Filler 3 (silane-treated barium glass powder).

Filler 4: A commercially available silane-treated silica-coated ytterbium fluoride product (SG-YBF100WSCMP10, average particle size: 110 nm, spherical, refractive index: 1.53, manufacturer: Sukyung AT Co.) was used as is.

Filler (d-1a)
Filler 5: Silane-treated titanium oxide 10 g of γ-methacryloyloxypropyltrimethoxysilane was dissolved in 10 g of toluene to prepare a solution, and 10 g of titanium oxide powder having a refractive index of 2.72 was added to this solution and stirred, after which the toluene was distilled off under reduced pressure, and subsequently, a heat treatment was carried out at 90° C. for 3 hours to obtain 18 g of silane-treated titanium oxide.

[Polymerization accelerator (f)]
DABE: ethyl 4-(N,N-dimethylamino)benzoate (polymerization accelerator for photopolymerization initiator)

[others]
BHT: 2,6-di-t-butyl-4-methylphenol (stabilizer)

[Refractive index]
The refractive index of the filler (d) and the polymerizable monomer mixture was measured in accordance with JIS K 0062:1992. Specifically, the refractive index was measured at 25°C by the immersion method using an Abbe refractometer with sodium D-line as a light source and diiodomethane in which sulfur was dissolved, 1-bromonaphthalene, methyl salicylate, dimethylformamide, 1-pentanol, or the like as a liquid (intermediate liquid). The refractive index of the polymerizable monomer mixture was measured by mixing the polymerizable monomer mixture, photopolymerization initiator, and polymerization accelerator to prepare a homogeneous solution, preparing a cured product by photopolymerization, and measuring the refractive index of the cured product. The cured product was cut out to obtain a cured plate having a width of 5 to 8 mm, a length of 15 to 25 mm, and a thickness of 3 mm, which was used as a measurement sample. The refractive index of the cured product of the polymerizable monomer mixtures in Examples 1 to 8 was 1.54, and the refractive index of the cured product of the polymerizable monomer mixture in Comparative Example 1 was 1.56.

[Examples 1 to 6 and Comparative Example 1]
A self-adhesive dental composite resin was prepared by mixing the components to obtain the composition shown in Table 1. The properties of the self-adhesive dental composite resin were evaluated by the methods described below.
[Preparation of test specimens]
The bovine mandibular anterior teeth were polished to expose the dentin, and a 1 mm thick plate-shaped dentin piece was prepared. The surface of the obtained dentin piece was polished with #1000 silicon carbide paper (manufactured by Nihon Kenshi Co., Ltd.) under running water. The obtained dentin piece was immersed in an acetate buffer of pH 4.5 and left in an incubator at 37°C. After 2 weeks, the dentin piece was removed and washed under running water. The obtained dentin piece had a demineralized layer (softened dentin) of about 150 μm in the depth direction from the dentin surface.

After drying the water on the surface of the dentin piece with an air blower, adhesive tape with a thickness of about 150 μm and a round hole with a diameter of 7 mm was attached to two places to define the treatment surface. A 38% aqueous solution containing 380 mg of diamine silver fluoride in 1 ml of water (manufactured by Toyo Pharmaceutical Co., Ltd., product name "Saffolide Solution for Dental Use 38%", hereinafter sometimes referred to as "Saffolide 38%) was applied to one of the round holes according to the attached instructions. Polyethylene tubes with an inner diameter of 7 mm and a height of 2 mm were placed on the two tapes so that the holes overlapped, and the tubes were filled with the self-adhesive dental composite resin (X) shown in Table 1. The top surface of the tube was covered with a slide glass, and light was irradiated from the top surface with a dental LED irradiator (manufactured by Ultradent, product name "VALO") for 20 seconds. By peeling off the slide glass, test pieces were obtained in which a self-adhesive dental composite resin with a diameter of 7 mm and a height of 2 mm was formed on the softened dentin treated with 38% safolide and on the untreated softened dentin. The test pieces were stored in distilled water at 37°C for 24 hours, and then the difference in color tone (ΔE*) between the self-adhesive dental composite resin formed on the softened dentin surface treated with an aqueous solution containing silver diammine fluoride and the untreated softened dentin surface, and the penetration depth of the silver component into the softened dentin were measured using the method described below. The transparency (ΔL*) of the self-adhesive dental composite resin was measured by preparing a 1 mm plate using the method described below.

[Transparency of cured self-adhesive dental composite resin]
Two 1 mm thick metal spacers were placed on a glass slide, and an appropriate amount of the self-adhesive dental composite resin shown in Table 1 was placed between the two metal spacers. Another glass slide was pressed from above and fixed with a clamp. The self-adhesive dental composite resin was irradiated with light from the top for 20 seconds using a dental LED irradiator (Ultradent, product name "VALO"). The back side was also irradiated with light for 20 seconds in the same manner, and then removed from the glass slide to obtain a test piece of the cured product of the self-adhesive dental composite resin with a thickness of 1 mm. Using a spectrophotometer (SE6000: manufactured by Nippon Denshoku Kogyo Co., Ltd.), the lightness was measured by placing a standard white board behind the test piece with a D65 light source and a field of view of 2 degrees, and the lightness was measured by placing a standard black board behind the same test piece, and the difference between the two was calculated as the transparency (ΔL*) (n=3). The larger the value of ΔL*, the higher the transparency of the cured product.

[Difference in color tone (ΔE*) between the self-adhesive dental composite resin formed on the softened dentin surface treated with an aqueous solution containing silver diammine fluoride and the untreated softened dentin surface]
Using a spectrophotometer (SE6000: manufactured by Nippon Denshoku Industries Co., Ltd.), the cured surface of the self-adhesive dental composite resin was placed in the measurement window, and the color tone of the self-adhesive dental composite resin formed on the softened dentin surface treated with an aqueous solution containing silver diamine fluoride and the untreated softened dentin surface was measured with a D65 light source and a 2-degree visual field. From the obtained L*, a*, and b* values, the color tone difference (ΔE*) between the softened dentin surface treated with an aqueous solution containing silver diamine fluoride and the self-adhesive dental composite resin formed on the untreated softened dentin surface was calculated (n=3). The larger the ΔE* value, the larger the color tone difference.

[Penetration depth of silver component into softened dentin]
The dentin plate-shaped pieces on which the self-adhesive dental composite resin was formed were fixed to a low-speed diamond saw and cut vertically along the center line of the cylindrical self-adhesive dental composite resin. The cut surfaces were polished with #3000 silicon carbide paper (manufactured by Nihon Kenshi Co., Ltd.) under running water, washed with running water, and then dried. Line analysis of silver element was performed with an energy dispersive X-ray analyzer (trade name "EMAX Evolution, X-MaxN20", manufactured by Horiba Ltd.) in a region of 250 μm in depth direction and width of 250 μm from the softened dentin surface at a line interval of 10 μm (scan number 20), and the limit depth at which silver element was detected in the depth direction of the dentin was defined as the penetration depth (n=3).

[Examples 7 to 8]
The color difference (ΔE*) and the penetration depth of the silver component into softened dentin were measured in the same manner as in Example 1, except that a 3.8% aqueous solution containing 38 mg of diamine silver fluoride in 1 ml of water (manufactured by Toyo Pharmaceutical Chemical Co., Ltd., product name ``Saholide RC Liquid for Dental Use 3.8%'', hereinafter sometimes referred to as ``Saholide 3.8%'') was used instead of Saholide 38%.

[Comparative Example 2]
The softened dentin after application of 38% sahoride was subjected to the same procedure as in Example 1, except that a dental adhesive (manufactured by Kuraray Noritake Dental Co., Ltd., product name "Clearfil Universal Bond Quick ER") and a dental composite resin (manufactured by Kuraray Noritake Dental Co., Ltd., product name "Clearfil AP-X, A3") were used as in the conventional method in place of the self-adhesive dental composite resin, in accordance with the attached instructions, to obtain test pieces in which dental composite resins with a diameter of 7 mm and a height of 2 mm were formed on the softened dentin treated with the sahoride solution and on the untreated softened dentin. After storing in distilled water at 37°C for 24 hours, the color difference (ΔE*) of the dental composite resins formed on the softened dentin treated with the aqueous solution containing diammine silver fluoride and on the untreated softened dentin, the penetration depth of the silver component into the softened dentin, and the transparency (ΔL*) of the dental composite resin were measured in the same manner as in Examples 1 to 8.

In the dental restoration kits according to Examples 1 to 8, the difference in color tone of the self-adhesive dental composite resin formed on softened dentin between cases where it was treated with an aqueous solution containing silver diamine fluoride and cases where it was not treated was slight, and sufficient penetration of the silver component into the softened dentin was observed. In the dental restoration kits according to Examples 1 to 8, the difference in color tone of the self-adhesive dental composite resin formed on softened dentin between cases where it was treated with an aqueous solution containing silver diamine fluoride and cases where it was not treated was small, so that the blackening that occurs when treated with an aqueous solution containing silver diamine fluoride was sufficiently concealed. In addition, the silver diamine fluoride preparations (product names "Safolide Dental Liquid 38%" and "Safolide RC Dental Liquid 3.8%") used to measure the penetration depth of the silver component into softened dentin have been confirmed to have clinical effects due to the silver component (silver nitrate), and the fact that sufficient penetration of the silver component into softened dentin has been confirmed means that the clinical effects of the silver component resulting from silver diamine fluoride can be obtained.

The dental restoration kit of Comparative Example 1 showed a large difference in color tone of the self-adhesive dental composite resin formed on softened dentin when it was treated with an aqueous solution containing silver diamine fluoride and when it was not, and the blackening caused by the aqueous solution containing silver diamine fluoride was not sufficiently concealed.

As shown in Comparative Example 2, when a conventional method for treating (inhibiting the progression of) or preventing dental caries was used, which involved treatment with an aqueous solution containing silver diamine fluoride, followed by treatment with a dental adhesive and a dental composite resin, the difference in color was slight, but the penetration of the silver component into the softened dentin was insufficient. The dental restoration kits of the present invention according to Examples 1 to 8 were significantly superior to Comparative Example 2 in terms of the penetration depth of the silver component into the softened dentin, without impeding the penetration of silver ions into the tooth tissue.

Claims (6)

A self-adhesive dental composite resin (X) containing a monomer (a) having an acidic group, a monomer (b) not having an acidic group, a polymerization initiator (c), and a filler (d);
and an aqueous solution (Y) containing diamine silver fluoride (e),
A dental restoration kit, wherein the transparency (ΔL*) of the self-adhesive dental composite resin (X) is 25 or less. The dental restoration kit according to claim 1, wherein the content of the filler (d) is 50 parts by mass or more in a total amount of 100 parts by mass of the self-adhesive dental composite resin (X). The dental restoration kit according to claim 1 or 2, wherein the filler (d) includes an inorganic filler (d-1), and the average particle size of the inorganic filler (d-1) is 0.001 to 50 μm. The dental restoration kit according to claim 3, wherein the inorganic filler (d-1) comprises a combination of at least one selected from the group consisting of quartz, silica, silica-zirconia, and barium glass, and silica-coated ytterbium fluoride. The dental restoration kit according to claim 3 or 4, further comprising an inorganic filler (d-1a) having a refractive index of 1.9 or more in addition to the inorganic filler (d-1), and the content of the inorganic filler (d-1a) is 0.001 parts by mass or more per 100 parts by mass of the total amount of the self-adhesive dental composite resin (X). The dental restoration kit according to claim 5, wherein the inorganic filler (d-1a) contains at least one selected from the group consisting of titanium oxide, zirconium oxide, and zinc oxide.