Dental composition kit

Abstract

Provided is a dental composition kit having a high mineral density recovery ability. The dental composition kit comprises an A liquid and a B liquid. The A liquid contains calcium ions (a1) and water (b1). The B liquid contains a compound (c) represented by formula (I) and having an acidic group: formula (I): R1-Xk, wherein in formula (I), R1 represents an organic group that has 40 or less carbon atoms and may or may not have at least one (meth) acryloyloxy group; X represents an acidic group; k represents an integer of 1 or 2; and when k is 2, the two acidic groups X are the same or different from each other; zinc ions (d1) and water (b2), and substantially does not contain a crosslinkable polymerizable monomer.

Description

Dental composition kit

[0001] The present invention relates to a dental composition kit.

[0002] Conventionally, dental compositions containing metal salts and dental composition kits in which two types of compositions are applied sequentially to the tooth surface have been proposed.

[0003] For example, Patent Document 1 discloses a hypersensitivity suppressant containing a zinc salt, an aluminum salt, and an anionic surfactant. Patent Document 2 discloses a dental treatment material for alleviating hypersensitivity, in which two liquids, A and B, each containing a substance that can rapidly form a sparingly soluble precipitate when mixed, are applied sequentially to the tooth surface to form a precipitate.

[0004] JP-A-3-258724 JP-A-4-217904

[0005] If a dental composition capable of restoring mineral density at sites of early caries on exposed root surfaces of teeth were available, it would be effective in restoring demineralized dentin. However, no useful dental composition with such properties has yet been proposed. The inventions described in Patent Documents 1 and 2 above are both aimed at alleviating dentin hypersensitivity, and these patent documents do not describe or suggest the restoration of mineral density. Patent Document 1 also fails to describe the incorporation of calcium ions and a hydrophilic solvent into the dentin hypersensitivity inhibitor. Patent Document 2 also describes the inclusion of calcium in Solution B, rather than Solution A, which is applied first, but does not describe the inclusion of calcium in Solution A.

[0006] In view of the above problems, an object of the present invention is to provide a dental composition kit having high mineral density restoring ability.

[0007] As a result of intensive research to solve the above-mentioned problems, the present inventors have discovered a new finding that in a dental composition kit comprising liquids A and B, such as a dental composition kit comprising liquids A and B, where liquids A and B are applied to the tooth surface in this order, when liquid A contains calcium ions and liquid B contains a compound having an acidic group and zinc ions, the mineral density of the tooth surface can be restored. Based on this finding, further research has led to the completion of the present invention.

[0008] That is, the present invention includes the following inventions: [1] A dental composition kit comprising a solution A and a solution B, wherein the solution A contains calcium ions (a1) and water (b1), and the solution B contains a compound (c) having an acidic group represented by the following formula (I), R １ -X ｋ ...Formula (I) [In formula (I), R １ represents an organic group having 40 or less carbon atoms, which may or may not have at least one (meth)acryloyloxy group. X represents an acidic group. k represents an integer of 1 or 2. When k is 2, the two acidic groups X are the same or different from each other.] A dental composition kit comprising zinc ions (d1) and water (b2), and substantially free of a crosslinkable polymerizable monomer. [2] The dental composition kit according to the above [1], wherein the solution B further comprises a hydrophilic solvent (e). [3] The dental composition kit according to the above [1] or [2], wherein the calcium ions (a1) are derived from at least one calcium compound (a) represented by the following formula (II): (Ca ２＋ ) ｃ ・(Y ｎ－ ) ｄ ...Formula (II) [In formula (II), Y ｎ－ represents an anion that serves as a counter ion for calcium ions. n represents an integer of 1, 2, or 3. c and d each represent an integer of 1, 2, or 3. c, d, and n are in a relationship that satisfies the formula 2c=nd.] [4] Calcium ions (a1) are CaCl ２ , CaBr ２ , CaI ２ , Ca(HCO ２ ) ２ , Ca(HCO ３ ) ２, and Ca(CH ３ COO) ２ [5] The dental composition kit according to any one of the above [1] to [4], wherein the compound (c) having an acidic group is represented by the following formula (III): R １ -((A ｍ－ ) ａ ・(H ＋ ) ｂ ) ｋ ...Formula (III) [In formula (III), R １ and k are as defined in formula (I). ｍ－ represents an m-valent acid anion group derived from the acidic group X. m represents an integer of 1, 2, or 3. a and b represent integers of 1, 2, or 3 such that am=b.] [6] The dental composition kit according to any one of the above [1] to [5], wherein the compound (c) having an acidic group is a compound represented by the following formula (IV): R ２ -R ３ -OP(=O)(-OH) ２ ...Formula (IV) [In formula (IV), R ２ represents a (meth)acryloyloxy group or hydrogen. ３ represents an alkylene group having 6 to 20 carbon atoms.] [7] The dental composition kit according to any one of the above [1] to [6], wherein the zinc ion (d1) is derived from at least one zinc compound (d) selected from the group consisting of ZnO and compounds represented by the following formula (V): (Zn ２＋ ) ｈ ・(P ｒ－ ) ｉ ...Formula (V) [In formula (V), P ｒ－ represents an anion that serves as a counter ion of the zinc ion. r represents an integer of 1, 2, or 3. h and i each represent an integer of 1, 2, or 3. h, i, and r are in a relationship that satisfies the formula 2h = ri.] [8] The zinc ion (d1) is ZnO, ZnCl ２ , Zn(OH) ２ , and ZnF ２The dental composition kit according to any one of the above [1] to [7], which is derived from at least one zinc compound (d) selected from the group consisting of:

[0009] The present invention provides a dental composition kit having high mineral density restoring ability.

[0010] In this specification, the upper and lower limits of the numerical ranges (contents of each component, values ​​calculated from each component, and each physical property, etc.) can be combined as appropriate.

[0011] [Dental Composition Kit] A dental composition kit according to an embodiment of the present invention is a dental composition kit comprising a solution A and a solution B, wherein the solution A contains calcium ions (a1) and water (b1), and the solution B contains a compound (c) having an acidic group represented by the following formula (I), R １ -X ｋ ...Formula (I) [In formula (I), R １ represents an organic group having 40 or less carbon atoms, which may or may not have at least one (meth)acryloyloxy group. X represents an acidic group. k represents an integer of 1 or 2. When k is 2, the two acidic groups X are the same or different from each other.] Contains zinc ions (d1) and water (b2), and is substantially free of crosslinkable polymerizable monomers. In this specification, "(meth)acryloyloxy" is a general term for methacryloyloxy and acryloyloxy. The same applies to other similar terms.

[0012] The inventors' studies have revealed that applying Solution A, which is a component of the dental composition kit described above, to a tooth surface, particularly an exposed root surface, at a site of early caries, i.e., a demineralized area of ​​dentin that has lost minerals, followed by application of Solution B on top of that, restores mineral density. The mechanism of action is presumed to be, but not limited to, the following: Application of Solution A, which contains calcium ions, causes calcium ions to penetrate into the collagen fiber layer exposed by demineralization of minerals. The calcium ions that penetrate into the collagen fiber layer are deposited between the collagen fibers, presumably serving as the starting point for mineral restoration. Furthermore, the layer formed using Solution B is presumably permeable to mineral components contained in saliva. Therefore, application of Solution A followed by Solution B allows minerals to be continuously supplied to the demineralized area through the layer formed using Solution B, increasing the mineral component concentration at the demineralized area. As a result, the calcium ions supplied by Solution A are thought to immobilize minerals, restoring the mineral density of the demineralized dentin. The order of application to the tooth surface is preferably liquid A followed by liquid B, but this is not necessarily limited to this; liquid B may also be applied to the tooth surface first. In this case, it is believed that some of the calcium ions derived from liquid A reach the collagen fiber layer via the layer formed using liquid B, thereby restoring the mineral density of the demineralized dentin through a mechanism similar to that described above. The degree of mineral density restoration when liquids B and A are applied in this order tends to be smaller than when liquids A and B are applied in this order. However, because the layer formed using liquid B is formed directly on the tooth surface, the layer's preservation is improved, and the supply of mineral components from saliva and the like is more easily stabilized.

[0013] <Solution A> Solution A contains calcium ions (a1) and water (b1). As described above, Solution A is applied to the tooth surface, particularly to the exposed root surface at the site of early caries, i.e., the demineralized area of ​​dentin where minerals have been lost, before Solution B. By applying Solution A containing calcium ions (a1), the calcium ions (a1) penetrate into the layer of collagen fibers exposed by the demineralization of minerals, and the calcium ions (a1) become deposited between the collagen fibers, which is thought to be the starting point for mineral recovery.

[0014] (Calcium ions (a1) and calcium compounds (a)) The calcium ions (a1) are derived from the calcium compound (a), and the calcium compound (a) dissolves in the water (b1), resulting in the calcium ions (a1) being contained in the solution A. The calcium ions (a1) are derived from, for example, at least one calcium compound (a) represented by the following formula (II): (Ca ２＋ ) ｃ ・(Y ｎ－ ) ｄ ...Formula (II) [In formula (II), Y ｎ－ represents an anion that serves as a counter ion for the calcium ion. n represents an integer of 1, 2, or 3. c and d each represent an integer of 1, 2, or 3. c, d, and n are in a relationship that satisfies the formula 2c=nd.]

[0015] In addition, calcium ions (a1) are selected from the viewpoints of solubility in water (b1) and safety when used in the oral cavity. ２ , CaBr ２ , CaI ２ , Ca(HCO ２ ) ２ , Ca(HCO ３ ) ２ , and Ca(CH ３ COO) ２ Preferably, the calcium compound (a) is derived from at least one calcium compound selected from the group consisting of CaCl ２ , CaBr ２ , and CaI ２It is more preferable that the calcium compound (a) is derived from at least one calcium compound selected from the group consisting of CaCl ２ The calcium compound (a) used in preparing Solution A may be one type alone or two or more types in combination. Therefore, the calcium ion (a1) in Solution A may be one type alone or two or more types.

[0016] The amount of calcium compound (a) to be incorporated into solution A is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more, relative to the mass (100% by mass) of water (b1), from the viewpoint of facilitating sufficient penetration of calcium into collagen fibers in the demineralized area, and is preferably 200% by mass or less, more preferably 180% by mass or less, and even more preferably 150% by mass or less, from the viewpoint of preventing excessive use of calcium compound (a). In other words, the content of calcium compound (a) is preferably 10 to 200% by mass, relative to 100% by mass of water (b1).

[0017] From the same viewpoint, the content of calcium ions (a1) in the above-mentioned Solution A is preferably 1.2% by mass or more, more preferably 2.3% by mass or more, even more preferably 3.1% by mass or more, relative to the total mass (100% by mass) of Solution A, and is preferably 10.7% by mass or less, more preferably 9.5% by mass or less, and even more preferably 8.9% by mass or less. In other words, the content of calcium ions (a1) in Solution A is preferably 1.2 to 10.7% by mass, relative to the total mass (100% by mass) of Solution A. The content of calcium ions (a1) in Solution A can be determined, for example, by measurement using an ICP atomic emission spectrometer.

[0018] (Water (b1)) The water (b1) preferably does not contain impurities that may have adverse effects, and is preferably distilled water or ion-exchanged water. The content of water (b1) in the above-mentioned Solution A is preferably 1 to 90% by mass, more preferably 5 to 85% by mass, and even more preferably 10 to 80% by mass, relative to 100% by mass of the mass of Solution A.

[0019] (Amount of calcium compound (a) and water (b1) in solution A) When the mass of solution A is taken as 100% by mass, the total mass of the calcium compound (a) and water (b1) in solution A is preferably 80 to 100% by mass, more preferably 90 to 100% by mass, and even more preferably 95 to 100% by mass, from the viewpoint of easily ensuring good permeability of calcium into collagen fibers in the demineralized area.

[0020] (Other Components) Solution A may further contain one or more other components other than calcium ions (a1) and water (b1). Examples of such other components include pH adjusters, polymerization inhibitors, ultraviolet absorbers, thickeners, colorants (dyes, pigments, etc.), fluorescent agents, and fragrances. Solution A may also contain, as the other components, fluoride ion-releasing substances such as sodium fluoride, potassium fluoride, sodium monofluorophosphate, lithium fluoride, strontium fluoride, and ytterbium fluoride. Solution A may also contain metal compounds such as silver oxide and aluminum hydroxide. The content of the other components is not particularly limited, and any amount sufficient to achieve the desired effect may be used. However, from the viewpoint of ensuring good calcium penetration into collagen fibers in the demineralized area, the content of the other components is preferably 0.01 to 1.5 parts by mass, more preferably 0.05 to 1.0 part by mass, and even more preferably 0.07 to 0.5 parts by mass per 100 parts by mass of Solution A. However, when the other component is an organic compound, the content thereof is set to 5 parts by mass or less, more preferably 3 parts by mass or less, per 100 parts by mass of the above-mentioned solution A.

[0021] <Solution B> Solution B contains a compound (c) having an acidic group represented by the following formula (I), R １ -X ｋ ...Formula (I) [In formula (I), R １represents an organic group having 40 or less carbon atoms, which may or may not have at least one (meth)acryloyloxy group. X represents an acidic group. k represents an integer of 1 or 2. When k is 2, the two acidic groups X are the same or different from each other.] The composition contains zinc ions (d1) and water (b2), and is substantially free of crosslinkable polymerizable monomers. As described above, after application of Solution A to the tooth surface, Solution B is applied onto the coating layer of Solution A. According to the inventors' studies, Solution B is a material that has the function of repairing and preventing early caries, and applying Solution B to an area affected by early caries protects and strengthens weakened areas of dentin. On the other hand, as described above, the layer formed using Solution B is believed to be permeable to mineral components contained in saliva. Therefore, minerals are supplied to the demineralized area over time through the layer formed using Solution B, increasing the concentration of components at the demineralized area.

[0022] (Compound (c) Having an Acidic Group) The compound (c) having an acidic group is a compound having an acidic group that, when mixed with water (b2) and, if necessary, a hydrophilic solvent (e), produces an acidic composition that exhibits an acid etching effect and a primer treatment effect on tooth tissue, and is a component that imparts demineralizing and penetrating effects. The compound (c) having an acidic group is preferably a compound represented by the following formula (III): R １ -((A ｍ－ ) ａ ・(H ＋ ) ｂ ) ｋ ...Formula (III) [In formula (III), R １ and k are as defined in formula (I). ｍ－ represents an m-valent acid anion group derived from the acidic group X. m represents an integer of 1, 2, or 3. a and b represent integers of 1, 2, or 3 such that am = b.

[0023] Examples of the compound (c) having an acidic group include compounds having at least one acidic group such as a phosphate group, a pyrophosphate group, a thiophosphate group, a phosphonate group, a sulfonic acid group, a carboxylic acid group, etc. Specific examples of the compound (c) having an acidic group are listed below.

[0024] Examples of the phosphate group-containing compound include octyl dihydrogen phosphate, decyl dihydrogen phosphate, dodecyl dihydrogen phosphate (also known as dodecyl phosphoric acid), tetradecyl dihydrogen phosphate, hexadecyl dihydrogen phosphate (also known as hexadecyl phosphoric acid), octadecyl dihydrogen phosphate, 2-(meth)acryloyloxyethyl dihydrogen phosphate, 3-(meth)acryloyloxypropyl dihydrogen phosphate, 4-(meth)acryloyloxybutyl dihydrogen phosphate, acryloyloxypentyl dihydrogen phosphate, 5-(meth)acryloyloxypentyl dihydrogen phosphate, 6-(meth)acryloyloxyhexyl dihydrogen phosphate, 7-(meth)acryloyloxyheptyl dihydrogen phosphate, 8-(meth)acryloyloxyoctyl dihydrogen phosphate, 9-(meth)acryloyloxynonyl dihydrogen phosphate, 10-(meth)acryloyloxydecyl dihydrogen phosphate, 11-(meth)acryloyloxyundecyl dihydrogen phosphate, 12-(meth)acryloyloxydodecyl dihydrogen phosphate, 16-(meth)acryloyloxyhexadecyl dihydrogen phosphate, 20-(meth)acryloyloxyicosyl dihydrogen 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 phosphate, bis[9-(meth)acryloyloxynonyl]hydrogen phosphate, bis[10-(meth)acryloyloxydecyl]hydrogen phosphate, 1,3-di(meth)acryloyloxypropyl dihydrogen phosphate, 2-(meth)acryloyloxyethylphenyl hydrogen phosphate, 2-(meth)acryloyloxyethyl-2-bromoethyl hydrogen phosphate, and bis[2-(meth)acryloyloxy-(1-hydroxymethyl)ethyl]hydrogen phosphate.

[0025] Examples of the pyrophosphate group-containing compound include bis[2-(meth)acryloyloxyethyl] pyrophosphate, bis[4-(meth)acryloyloxybutyl] pyrophosphate, bis[6-(meth)acryloyloxyhexyl] pyrophosphate, bis[8-(meth)acryloyloxyoctyl] pyrophosphate, and bis[10-(meth)acryloyloxydecyl] pyrophosphate.

[0026] Examples of the thiophosphate group-containing compound include 2-(meth)acryloyloxyethyl dihydrogenthiophosphate, 3-(meth)acryloyloxypropyl dihydrogenthiophosphate, 4-(meth)acryloyloxybutyl dihydrogenthiophosphate, 5-(meth)acryloyloxypentyl dihydrogenthiophosphate, 6-(meth)acryloyloxyhexyl dihydrogenthiophosphate, 7-(meth)acryloyloxyheptyl dihydrogenthiophosphate, 8-(meth)acryloyloxyethyl dihydrogenthiophosphate, 9-(meth)acryloyloxyethyl dihydrogenthiophosphate, 10-(meth)acryloyloxyethyl dihydrogenthiophosphate, 11-(meth)acryloyloxyethyl dihydrogenthiophosphate, 12-(meth)acryloyloxyethyl dihydrogenthiophosphate, 13-(meth)acryloyloxyethyl dihydrogenthiophosphate, 14-(meth)acryloyloxyethyl dihydrogenthiophosphate, 15-(meth)acryloyloxyethyl dihydrogenthiophosphate, 16-(meth)acryloyloxyethyl dihydrogenthiophosphate, 17-(meth)acryloyloxyethyl dihydrogenthiophosphate, 18-(meth)acryloyloxyethyl dihydrogenthiophosphate, 19-(meth)acryloyloxyethyl dihydrogenthiophosphate, 20-(meth)acryloyloxyethyl dihydrogenthiophosphate, 21-(meth)acryloyloxyethyl dihydrogenthiophosphate, 22-(meth)acryloyloxyethyl dihydrogenthiophosphate, 23-(meth)acryloyloxyethyl dihydrogenthiophosphate, 24-(meth)acryloyloxyethyl dihydrogenthiophosphate, 25-(meth)acryloyloxyethyl dihydrogenthiophosphate, 26-(meth)acryloyloxyethyl dihydrogenthiophosphate, 27-(meth)acryloyloxyethyl dihydrogenthiophosphate, 28-(meth)acrylo Examples of suitable alkyl acrylates include octyl dihydrogen thiophosphate, 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, and 20-(meth)acryloyloxyicosyl dihydrogen thiophosphate.

[0027] Examples of the phosphonic acid group-containing compound include 2-(meth)acryloyloxyethyl phenyl phosphonate, 5-(meth)acryloyloxypentyl-3-phosphonopropionate, 6-(meth)acryloyloxyhexyl-3-phosphonopropionate, 10-(meth)acryloyloxydecyl-3-phosphonopropionate, 6-(meth)acryloyloxyhexyl phosphonoacetate, and 10-(meth)acryloyloxydecyl phosphonoacetate.

[0028] Examples of sulfonic acid group-containing compounds include 2-(meth)acrylamido-2-methylpropanesulfonic acid, styrenesulfonic acid, and 2-sulfoethyl(meth)acrylate.

[0029] Carboxylic acid group-containing compounds include compounds having one carboxy group in the molecule and compounds having multiple carboxy groups in the molecule.

[0030] Examples of compounds having one carboxy group in the molecule include (meth)acrylic acid, N-(meth)acryloylglycine, N-(meth)acryloylaspartic acid, O-(meth)acryloyltyrosine, N-(meth)acryloyltyrosine, N-(meth)acryloylphenylalanine, N-(meth)acryloyl-p-aminobenzoic acid, N-(meth)acryloyl-o-aminobenzoic acid, p-vinylbenzoic acid, 2-(meth)acryloyl Examples of the acryloyloxybenzoic acid include N-(meth)acryloyl-5-aminosalicylic acid, N-(meth)acryloyl-4-aminosalicylic acid, 2-(meth)acryloyloxyethyl hydrogen succinate, 2-(meth)acryloyloxyethyl hydrogen phthalate, and 2-(meth)acryloyloxyethyl hydrogen maleate.

[0031] Examples of compounds having multiple carboxy groups in the molecule include 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)acryloyloxy Examples include tridecane-1,1-dicarboxylic acid, 4-(meth)acryloyloxyethyl trimellitate, 4-(meth)acryloyloxybutyl trimellitate, 4-(meth)acryloyloxyhexyl trimellitate, 4-(meth)acryloyloxydecyl trimellitate, and 2-(meth)acryloyloxyethyl-3'-(meth)acryloyloxy-2'-(3,4-dicarboxybenzoyloxy)propyl succinate.

[0032] The compound (c) having an acidic group is more preferably a compound represented by the following formula (IV): ２ -R ３ -OP(=O)(-OH) ２ ...Formula (IV) [In formula (IV), R ２ represents a (meth)acryloyloxy group or hydrogen. ３ represents an alkylene group having 6 to 20 carbon atoms.

[0033] Among these compounds (c) having an acidic group, phosphate group- or pyrophosphate group-containing compounds are preferred because they exhibit superior deposit formation on tooth tissue, and phosphate group-containing compounds are particularly preferred. Among these, divalent phosphate group-containing compounds having an alkyl or alkylene group with 6 to 20 carbon atoms as the main chain in the molecule are more preferred because they exhibit high tooth demineralization properties and high deposit formation, and divalent phosphate group-containing compounds having an alkyl or alkylene group with 8 to 12 carbon atoms as the main chain in the molecule, such as dodecyl dihydrogen phosphate and 10-methacryloyloxydecyl dihydrogen phosphate, are most preferred.

[0034] The compound (c) having an acidic group may be used alone or in combination of two or more kinds.

[0035] From the viewpoint of easily ensuring the effects of the present invention, the content of the compound (c) having an acidic group is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, relative to 100% by mass of the total mass of the compound (c) having an acidic group, the zinc compound (d) described below, and water (b2) in the above-mentioned Solution B. It is also preferably 70% by mass or less, more preferably 60% by mass or less. In other words, the content of the compound (c) having an acidic group is preferably 10 to 70% by mass, relative to 100% by mass of the total mass of the compound (c) having an acidic group, the zinc compound (d), and water (b2). Furthermore, when the solution B contains a hydrophilic solvent (e), the content of the compound (c) having an acidic group is, from the viewpoint of easily ensuring the effects of the present invention, preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, relative to 100% by mass of the total mass of the compound (c) having an acidic group, the zinc compound (d), water (b2), and the hydrophilic solvent (e) in the solution B. Also, it is preferably 50% by mass or less, more preferably 40% by mass or less. In other words, the content of the compound (c) having an acidic group is preferably 5 to 50% by mass, relative to 100% by mass of the total mass of the compound (c) having an acidic group, the zinc compound (d), water (b2), and the hydrophilic solvent (e).

[0036] (Zinc ion (d1)) The zinc ion (d1) is derived from the zinc compound (d). When the zinc compound (d) is dissolved by the compound (c) having an acidic group, the zinc ion (d1) is contained in the solution B. The zinc ion (d1) is preferably derived from at least one zinc compound (d) selected from the group consisting of ZnO and compounds represented by the following formula (V): (Zn ２＋ ) ｈ ・(P ｒ－ ) ｉ ...Formula (V) [In formula (V), P ｒ－represents an anion that serves as a counter ion to the zinc ion. r represents an integer of 1, 2, or 3. h and i each represent an integer of 1, 2, or 3. h, i, and r are in a relationship that satisfies the formula 2h = ri.]

[0037] The zinc ion (d1) may be, for example, ZnO, ZnCl ２ , Zn(OH) ２ , and ZnF ２ The zinc compound (d) used in preparing the solution B may be one type alone or two or more types in combination. Therefore, the zinc ion (d1) in the solution B may be one type alone or two or more types.

[0038] The amount of zinc compound (d) to be added to the above-mentioned Solution B is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, and even more preferably 1.5% by mass or more, relative to the total mass (100% by mass) of the compound (c) having an acidic group and water (b2), from the viewpoint of facilitating the successful formation of deposits for strengthening tooth structure, and is preferably 15% by mass or less, more preferably 12% by mass or less, and even more preferably 10% by mass or less, from the viewpoint of preventing excessive neutralization of the acidic group of the compound (c) having an acidic group and ensuring good decalcification and penetration. In other words, the content of zinc compound (d) in Solution B is preferably 0.5 to 15% by mass, relative to the total mass (100% by mass) of the compound (c) having an acidic group and water (b2). Furthermore, when the solution B contains the hydrophilic solvent (e), the amount of the zinc compound (d) to be blended into the solution B is, from the same viewpoint, preferably 0.3% by mass or more, more preferably 0.6% by mass or more, even more preferably 0.8% by mass or more, and is preferably 10% by mass or less, more preferably 7.0% by mass or less, and even more preferably 5.0% by mass or less, relative to the total mass (100% by mass) of the compound (c) having an acidic group, water (b2), and the hydrophilic solvent (e). In other words, the content of the zinc compound (d) in the solution B is preferably 0.3 to 10% by mass, relative to the total mass (100% by mass) of the compound (c) having an acidic group, water (b2), and the hydrophilic solvent (e).

[0039] From the same viewpoint, the content of zinc ions (d1) in the solution B is preferably 0.2% by mass or more, more preferably 0.4% by mass or more, even more preferably 0.7% by mass or more, and is preferably 12% by mass or less, more preferably 10% by mass or less, and even more preferably 8.0% by mass or less, relative to the total mass (100% by mass) of the compound (c) having an acidic group and the water (b2). In other words, the content of zinc ions (d1) in the solution B is preferably 0.2 to 12% by mass, relative to the total mass (100% by mass) of the compound (c) having an acidic group and the water (b2). Furthermore, when the solution B contains a hydrophilic solvent (e), the content of zinc ions (d1) in the solution B is, from the same viewpoint, preferably 0.1% by mass or more, more preferably 0.2% by mass or more, even more preferably 0.3% by mass or more, and preferably 8.0% by mass or less, more preferably 5.6% by mass or less, and even more preferably 4.0% by mass or less, based on the total mass (100% by mass) of the compound (c) having an acidic group, water (b2), and the hydrophilic solvent (e). In other words, the content of zinc ions (d1) in the solution B is preferably 0.1 to 8.0% by mass, based on the total mass (100% by mass) of the compound (c) having an acidic group, water (b2), and the hydrophilic solvent (e). The content of zinc ions (d1) in the solution B can be calculated based on the amount of the zinc compound (d), and the content of zinc ions (d1) can also be determined by measurement using an ICP atomic emission spectrometer.

[0040] (Water (b2)) The water (b2) preferably does not contain impurities that may have adverse effects, and distilled water or ion-exchanged water is preferred. The content of water (b2) in the above-mentioned Solution B is preferably 1 to 90% by mass, more preferably 5 to 80% by mass, and even more preferably 10 to 70% by mass, relative to 100% by mass of the total mass of the compound (c) having an acidic group, the zinc compound (d), the water (b2), and the hydrophilic solvent (e). Furthermore, when the above-mentioned Solution B contains a hydrophilic solvent (e), the content of water (b2) in the above-mentioned Solution B is preferably 1 to 50% by mass, more preferably 5 to 40% by mass, and even more preferably 10 to 30% by mass, relative to 100% by mass of the total mass of the compound (c) having an acidic group, the zinc compound (d), the water (b2), and the hydrophilic solvent (e).

[0041] (Amounts of the compound (c) having an acidic group, the zinc compound (d), and the water (b2) in Solution B) The total mass of the compound (c) having an acidic group, the zinc compound (d), and the water (b2) in Solution B, when the mass of Solution B is taken as 100% by mass, is preferably 10 to 60% by mass, more preferably 20 to 55% by mass, and even more preferably 30 to 50% by mass, from the viewpoint of favorable formation of deposits for strengthening tooth structure. Furthermore, when the above-mentioned Solution B contains a hydrophilic solvent (e), the total mass of the compound (c) having an acidic group, the zinc compound (d), the water (b2), and the hydrophilic solvent (e) in Solution B, when the mass of Solution B is taken as 100% by mass, is preferably 85 to 100% by mass, more preferably 90 to 100% by mass, and even more preferably 93 to 100% by mass, from the viewpoint of favorable formation of deposits for strengthening tooth structure and favorable application to tooth surfaces.

[0042] (Hydrophilic Solvent (e)) Solution B may further contain a hydrophilic solvent (e) as an optional component. The hydrophilic solvent (e) refers to an organic compound having a solubility in water at 25°C of 10% by mass or more, preferably 30% by mass or more, and more preferably capable of dissolving in water at any ratio at 25°C. The hydrophilic solvent (e) may be a single compound or a mixture of multiple compounds.

[0043] Examples of the hydrophilic solvent (e) include ethanol, 2-propanol, 2-methyl-2-propanol, acetone, tetrahydrofuran, 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, polyethylene glycol di(meth)acrylate (having 9 or more oxyethylene groups), N,N- Examples of suitable (meth)acrylamide include dimethylaminoethyl methacrylate, 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-[3-(dimethylamino)propyl]acrylamide, and (meth)acrylamides represented by the following formula (VI):

[0044] [In the above formula (VI), R 4 and R ５ are each independently an alkyl group having 1 to 3 carbon atoms (e.g., a methyl group, an ethyl group, an n-propyl group, an isopropyl group, etc.) which may have a substituent (e.g., a hydroxyl group, etc.), R ６ is a hydrogen atom or a methyl group.

[0045] Among these hydrophilic solvents (e), ethanol, 2-propanol, 2-methyl-2-propanol, acetone, tetrahydrofuran, 2-hydroxyethyl (meth)acrylate, 2,3-dihydroxypropyl (meth)acrylate, N,N-dimethylaminoethyl methacrylate, diacetone (meth)acrylamide, and hydrophilic monofunctional (meth)acrylamide monomers are preferred, and ethanol, 2-propanol, 2-hydroxyethyl (meth)acrylate, N,N-dimethylaminoethyl methacrylate, and monofunctional (meth)acrylamide monomers represented by formula (VI) are more preferred. One type of hydrophilic solvent (e) may be blended alone, or two or more types may be blended in combination.

[0046] The hydrophilic solvent (e) functions as a co-solvent for the compound (c) having an acidic group and water (b2). The content of the hydrophilic solvent (e) in the solution B is preferably 1 to 90% by mass, more preferably 5 to 80% by mass, and even more preferably 10 to 70% by mass, relative to 100% by mass of the total mass of the compound (c) having an acidic group, the zinc compound (d), the water (b2), and the hydrophilic solvent (e).

[0047] <Organic Compounds Other than the Compound (c) Having an Acidic Group and the Hydrophilic Solvent (e)> The above-mentioned Solution B is substantially free of crosslinkable polymerizable monomers, which are organic compounds other than the compound (c) having an acidic group and the hydrophilic solvent (e). Specifically, "substantially free" here means that the crosslinkable polymerizable monomer is present in an amount of 5 parts by mass or less, preferably 3 parts by mass or less, per 100 parts by mass of the above-mentioned Solution B. Examples of the crosslinkable polymerizable monomer include hydrophobic crosslinkable polymerizable monomers that do not have an acidic group, such as aromatic bifunctional monomers, aliphatic bifunctional monomers, and trifunctional or higher functional monomers. By being substantially free of crosslinkable polymerizable monomers, the Solution B according to the present invention can avoid inhibiting the complexation of the compound (c) having an acidic group, zinc ions (d1), and inorganic components of demineralized tooth tissue, thereby promoting the formation of deposits due to these compounds.

[0048] Examples of the aromatic bifunctional monomer 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, and acryloyloxydipropoxyphenyl)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.

[0049] Examples of the aliphatic difunctional monomer include glycerol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, and the like. Examples of such an acrylamide include diol di(meth)acrylate, 1,2-bis(3-methacryloyloxy-2-hydroxypropoxy)ethane, 2,2,4-trimethylhexamethylenebis(2-carbamoyloxyethyl)di(meth)acrylate, N-methacryloyloxyethyl acrylamide, N-methacryloyloxypropyl acrylamide, N-methacryloyloxybutyl acrylamide, N-(1-ethyl-(2-methacryloyloxy)ethyl)acrylamide, and N-(2-(2-methacryloyloxyethoxy)ethyl)acrylamide.

[0050] Examples of the tri- or higher functional monomers include trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, trimethylolmethane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, N,N-(2,2,4-trimethylhexamethylene)bis[2-(aminocarboxy)propane-1,3-diol]tetra(meth)acrylate, and 1,7-diacryloyloxy-2,2,6,6-tetra(meth)acryloyloxymethyl-4-oxyheptane.

[0051] It is preferable that the above-mentioned Solution B contains substantially no organic compounds other than the compound (c) having an acidic group and the hydrophilic solvent (e), including the above-mentioned crosslinkable polymerizable monomer. Here, "substantially no organic compounds" specifically means that the amount of the organic compounds other than the compound (c) having an acidic group and the hydrophilic solvent (e) is 5 parts by mass or less, preferably 3 parts by mass or less, per 100 parts by mass of the above-mentioned Solution B. Examples of organic compounds other than the compound (c) having an acidic group and the hydrophilic solvent (e), which are substances other than the crosslinkable polymerizable monomer, include: photopolymerization initiators such as (bis)acylphosphine oxides, thioxanthones or quaternary ammonium salts of thioxanthones, ketals, α-diketones, coumarins, anthraquinones, benzoin alkyl ether compounds, and α-aminoketone compounds; polymerization accelerators such as aldehydes, thiol compounds, and aminobenzoic acid ester compounds; antibacterial substances such as cetylpyridinium chloride, benzalkonium chloride, (meth)acryloyloxydodecylpyridinium bromide, (meth)acryloyloxyhexadecylpyridinium chloride, (meth)acryloyloxydecylammonium chloride, triclosan, and 12-methacryloyloxydodecylpyridinium bromide; Monofunctional polymerizable monomers such as 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, and octafluoropentyl (meth)acrylate; and the like.

[0052] Examples of (bis)acylphosphine oxides used as the photopolymerization initiator include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylmethoxyphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and 2,4,6-trimethylbenzoylphenylphosphine oxide sodium salt. Examples of α-diketones used as the photopolymerization initiator include diacetyl, benzyl, camphorquinone, 2,3-pentadione, 2,3-octadione, 9,10-phenanthrenequinone, 4,4′-oxybenzyl, and acenaphthenequinone.

[0053] Specific examples of aldehydes used as the polymerization accelerator include terephthalaldehyde and benzaldehyde derivatives. Examples of benzaldehyde derivatives include dimethylaminobenzaldehyde, p-methoxybenzaldehyde, p-ethoxybenzaldehyde, and p-n-octyloxybenzaldehyde. Specific examples of thiol compounds used as the polymerization accelerator include 2-mercaptobenzoxazole, decanethiol, 3-mercaptopropyltrimethoxysilane, and thiobenzoic acid. Specific examples of the aminobenzoic acid ester compound used as the polymerization accelerator include ethyl 4-(N,N-dimethylamino)benzoate, methyl 4-(N,N-dimethylamino)benzoate, n-butoxyethyl 4-N,N-(dimethylamino)benzoate, 2-[(meth)acryloyloxy]ethyl 4-(N,N-dimethylamino)benzoate, 4-(N,N-dimethylamino)benzophenone, and n-butyl 4-(N,N-dimethylamino)benzoate.

[0054] <Other Components> Solution B may further contain one or more other components. Examples of such other components include pH adjusters, polymerization inhibitors, UV absorbers, thickeners, colorants (dyes, pigments, etc.), fluorescent agents, and fragrances. Solution B may also contain, as the other component, a fluoride ion-releasing substance such as sodium fluoride, potassium fluoride, sodium monofluorophosphate, lithium fluoride, strontium fluoride, or ytterbium fluoride. Solution B may also contain metal compounds such as calcium hydroxide, calcium chloride, silver oxide, and aluminum hydroxide. The content of the other components is not particularly limited, and any amount sufficient to achieve the desired effect may be used. However, from the viewpoint of ensuring the permeability of mineral components, the content is preferably 0.01 to 1 part by mass, more preferably 0.05 to 0.5 parts by mass, and even more preferably 0.07 to 0.3 parts by mass per 100 parts by mass of Solution B. However, when the other component is an organic compound, its content is set to 8 parts by mass or less, more preferably 5 parts by mass or less, per 100 parts by mass of the above-mentioned solution B.

[0055] [Characteristics of Dental Composition Kit] As described above, the dental composition kit according to the embodiment of the present invention exhibits high mineral density restoration ability by applying liquid A and liquid B to the tooth surface, particularly by applying liquid A and liquid B to the tooth surface in that order. The mineral density restoration ability of the dental composition kit is calculated by applying liquid A and liquid B to a demineralized bovine tooth sample, immersing the sample in artificial saliva under predetermined conditions, obtaining an image of the tooth surface of the sample by contact microradiography (CMR), analyzing and integrating the brightness values ​​at predetermined depths, and calculating the value relative to a bovine tooth sample to which liquid A and liquid B have not been applied; specifically, the measurement and calculation are carried out according to the procedures described in the Examples.

[0056] The mineral density recovery capacity of the dental composition kit according to the embodiment of the present invention is preferably 17% or more, more preferably 18% or more, even more preferably 19% or more, and even more preferably 20% or more. There is no particular upper limit, but from the viewpoint of ease of manufacturing the dental composition kit, it is, for example, 35%. In other words, the mineral density recovery capacity of the dental composition kit according to the embodiment of the present invention is preferably 17 to 35%.

[0057] [Methods for Producing Solutions A and B] Solution A can be produced by mixing calcium compound (a) with water (b1) to dissolve the solid calcium compound (a) in the water (b1). If Solution A contains other components, these components can be added at any time. Solution B can be produced by adding a compound (c) having an acidic group, a zinc compound (d), water (b2), and, if necessary, a hydrophilic solvent (e) in any order, and finally dissolving the solid zinc compound (d) in a liquid mixture composition containing the compound (c) having an acidic group, water (b2), and the hydrophilic solvent (e). Solution B can be produced by adding the compound (c) having an acidic group, water (b2), and the hydrophilic solvent (e) in any order. If Solution B contains other components, these components can be added at any time.

[0058] [Method of using the dental composition kit] Both of the above-mentioned solutions A and B can be applied to the tooth using a cotton ball, a small piece of sponge, a small brush, an applicator brush, or the like. After application, if necessary, air is blown using a three-way syringe or the like to dry the evaporated components, completing the treatment. It is preferable to dry solution A after application before applying solution B. Because the application of solutions A and B to the tooth is a simple procedure, the stress experienced by both the practitioner and the patient is minimal, even when treating multiple teeth.

[0059] The present invention includes embodiments in which the above-described configurations are combined 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.

[0060] The dental composition kit according to the present invention will be specifically described below using examples, but the dental composition kit according to the present invention is not limited to the following examples.

[0061] The abbreviations for the various components used in the examples and comparative examples are as follows:

[0062] [Compound (c) having an acidic group] MHP: 6-methacryloyloxyhexyl dihydrogen phosphate MDP: 10-methacryloyloxydecyl dihydrogen phosphate M12P: 12-methacryloyloxydodecyl dihydrogen phosphate 4-MET: 4-methacryloyloxyethyl trimellitate

[0063] [Hydrophilic Solvent (e)] HEMA: 2-hydroxyethyl methacrylate DEAA: N,N-diethylacrylamide (compound represented by formula (VI)) DMAEMA: N,N-dimethylaminoethyl methacrylate

[0064] [Organic compounds other than the compound (c) having an acidic group and the hydrophilic solvent (e)] CPC: cetylpyridinium chloride MDPB: 12-methacryloyloxydodecylpyridinium bromide Bis-GMA: 2,2-bis[4-(3-methacryloyloxy-2-hydroxypropoxy)phenyl]propane CQ: DL-camphorquinone EDMB: ethyl 4-(N,N-dimethylamino)benzoate

[0065] [Preparation and Evaluation of Dental Composition Kits] <Examples 1 to 11 and Comparative Examples 1 to 4> Dental composition kits were prepared by mixing the materials according to the formulations shown in Table 1 to prepare liquid A and liquid B for each Example and Comparative Example. Samples were then prepared using each dental composition kit according to the following procedure, and measurements and evaluations were performed using the samples according to the following procedure. Note that for Comparative Example 1, liquid A was not used, and only liquid B was used. Furthermore, for Example 11, liquid B in Table 1 was used first as "liquid A" in "(4) Preparation of test pieces" described below, and liquid A in Table 1 was used second as "liquid B" in "(4) Preparation of test pieces" described below.

[0066] <Evaluation of mineral density recovery ability> The ability to promote remineralization of demineralized dentin was evaluated as mineral density recovery ability using the following method: (1) Preparation of demineralization solution A 50 mM aqueous solution of acetic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) and a 50 mM aqueous solution of sodium acetate trihydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were mixed and adjusted to pH 4.5. (2) Preparation of Artificial Saliva 87.6 mg of sodium chloride (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.), 122 mg of potassium dihydrogen phosphate (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.), 166 mg of calcium chloride (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.), and 477 mg of 2-[4-(2-hydroxyethyl)-1-piperazinyl]ethanesulfonic acid (HEPES) (manufactured by Dojindo Laboratories, Inc.) were dissolved in approximately 500 mL of water, and the pH was adjusted to 7.0 with a saturated aqueous solution of NaOH (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.), and the volume was then increased to 1.0 L.

[0067] (3) Reagents used in preparing test pieces The following compounds were used in preparing test pieces: Ethanol: manufactured by Kanto Chemical Co., Ltd. Propylene oxide: manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Epoxy resin base: (Epocure 2 base, manufactured by Buehler) Curing agent (Epocure 2 curing agent, manufactured by Buehler)

[0068] (4) Preparation of Test Specimens Test specimens were prepared using the cervical region of bovine teeth according to the following procedure. The surface of the cervical region of bovine teeth was polished with #80 abrasive paper to expose the dentin, followed by further polishing with #1000 abrasive paper and ultrasonic treatment for 5 minutes. A portion of the surface of the treated cervical specimen was designated as a test window of approximately 5 mm x 2 mm. Using a diamond cutter (Isomet 1000, manufactured by Bühler), the cervical specimen was divided into two sections so that the test window area was symmetrical about the divided surface. Two test specimens, each with a 5 mm x 1 mm test window, were prepared by applying nail polish to the areas of both sections other than the test window. Both test specimens were immersed in a decalcifying solution and decalcified at 37°C for two weeks. The decalcifying solution was replaced every three days. After removing the nail polish from the backside of both test specimens, nail polish was applied to the test window (test window A) of one of the test specimens and allowed to dry. The test window (test window B) of the other test specimen was immersed in 4 μL of artificial saliva for 1 hour, dried with an air blower, and then a sample (dental composition kit of each Example and Comparative Example) was applied. The dental composition kit was applied to test window B as follows: First, liquid A was applied to test window B, left to stand for 10 seconds, and then dried with an air blower. Subsequently, liquid B was applied, left to stand for 10 seconds, and then dried with an air blower. Both test specimens were immersed in artificial saliva and stored at 37° C. for 14 days. The artificial saliva was replaced 10 times within 14 days of the start of immersion. The nail polish was removed from the resulting test pieces, and the pieces were immersed in 70% by volume ethanol, 80% by volume ethanol, 90% by volume ethanol, 99% by volume ethanol, and 100% by volume ethanol for 10 minutes each, followed by 100% by volume ethanol for 1 day. The pieces were immersed in a propylene oxide / ethanol mixture (1 / 1 volume ratio) and propylene oxide for 10 minutes each, followed by propylene oxide for 1 day. The pieces were immersed in an epoxy resin / propylene oxide mixture (1 / 1 volume ratio), an epoxy resin / propylene oxide mixture (4 / 1 volume ratio), and an epoxy resin mixture (4 / 1 volume ratio) for 2 hours each, followed by immersion in an epoxy resin / curing agent mixture (4 / 1 volume ratio), and then stored at 37°C for 1 day while immersed, followed by curing.The test specimens, which were the cured products, were cut perpendicular to the long sides of the test window using a diamond cutter (Isomet 1000, manufactured by BUEHLER) to a thickness of approximately 1.2 mm, and the thickness of the test specimens was adjusted to 0.100 mm to 0.150 mm using wrapping film (#1200, #3000, #8000, manufactured by 3M Japan Ltd.).

[0069] (5) Acquisition of CMR Images For both test specimens obtained, a soft X-ray inspection device (trade name "CMR-2", manufactured by Softex Co., Ltd.) and a glass dry plate (HIGH PRECISION PHOTO PLATE HPP-SN2 2x2, manufactured by Konica Minolta, Inc.) were used to photograph the entire test specimen at a tube voltage of 10 to 15 kV, a tube current of 2.0 mA, and an irradiation time of 10 minutes, and a Contact Microradiography (CMR) image (CMR image) was obtained. The photographed test specimen (dry plate) was immersed in a developer (medical X-ray liquid developer "Hilendor", manufactured by Fujifilm Corporation) for 5 minutes, washed with distilled water for 1 minute, and then immersed in a fixer (fixer "Hilendor", manufactured by Fujifilm Corporation) for 5 minutes and washed with distilled water for 30 seconds.

[0070] (6) Calculation of mineral density recovery capacity by CMR image analysis The obtained CMR image was photographed with a microscope (Nikon DS-Ri1, manufactured by Nikon Solutions Corporation), and the brightness value at a depth of 700 μm in the test window was used as a reference. Image analysis software (ImageJ, open source, public domain) was used to measure the brightness value from the surface of the test window in the depth direction of the test window. The measurement interval was set to 5 μm for the depth range from 0 μm to 700 μm, and the mineral density recovery capacity (%) was calculated based on the following formula 1. Mineral density recovery capacity (%) = {[(DT ０ -DC ０ ) + (DT ５ -DC ５ ) + (DT １０ -DC １０ ) + ... + (DT ７００ -DC ７００ ) ÷ [(1-DC ０ ) + (1-DC ５ ) + (1-DC １０ )+...+(1-DC ７００) )]}×100 (Formula 1) The meanings of the symbols in the above formula 1 are as follows. In the following, "control" means a case where no treatment was performed with the sample (dental composition kit of each example and comparative example). DC ｘ : Control mineral density at depth x μm BC ｘ : Control brightness value at depth x μm DT ｘ : Mineral density of the treated surface at a depth of x μm BT ｘ : Brightness value of the processed surface at a depth of x μm. ｘ " and "DT ｘ " is calculated using the following formula: DC ｘ =BC ｘ / BC ７００ ... (Formula 2) DT ｘ =BT ｘ / BT ７００ ...(Equation 3)

[0071] Three test pieces were prepared for each example and comparative example, and the mineral density recovery ability of each test piece was measured using the above procedure. The arithmetic mean value was calculated and used as the mineral density recovery ability of each example and comparative example. The measurement results for each example and comparative example are shown in Table 1, along with the composition of each dental composition kit.

[0072]

[0073] As shown in Table 1, in Examples 1 to 11, in which Solution A containing the above components (a1) and (b1) and Solution B containing the above components (c), (d1), and (b2) but substantially free of crosslinkable polymerizable monomers were applied to the tooth surface, higher mineral density recovery abilities were obtained compared to the Comparative Examples. In particular, in Examples 1 to 10, in which Solutions A and B were applied to the tooth surface in this order, high mineral density recovery abilities of over 20% were obtained. On the other hand, Comparative Example 2, which used Solution B containing a crosslinkable polymerizable monomer; Comparative Example 3, which used Solution B containing no zinc ions; and Comparative Example 4, which used Solution B containing no compound (c) having an acidic group, all showed significantly lower mineral density recovery abilities compared to the Examples. Furthermore, Comparative Example 1, in which Solution A was not used, also showed a significantly lower mineral density recovery ability compared to the Examples.

[0074] The dental composition kit of the present invention has a high mineral density recovery ability and can restore initially demineralized tooth tissue through simple procedures, making it particularly suitable for use in preventive treatment of root caries and restorative treatment of early caries.

Claims

1. A dental composition kit comprising a liquid A and a liquid B, wherein the liquid A contains calcium ions (a1) and water (b1), and the liquid B contains a compound (c) having an acidic group represented by the following formula (I), R １ -X ｋ ...Formula (I) [In formula (I), R １ represents an organic group having 40 or less carbon atoms which may or may not have at least one (meth)acryloyloxy group. X represents an acidic group. k represents an integer of 1 or 2. When k is 2, the two acidic groups X are the same or different from each other.] A dental composition kit comprising zinc ions (d1) and water (b2), and substantially free of a crosslinkable polymerizable monomer.

2. The dental composition kit according to claim 1, wherein said solution B further comprises a hydrophilic solvent (e).

3. The dental composition kit according to claim 1 or 2, wherein the calcium ion (a1) is derived from at least one calcium compound (a) represented by the following formula (II): (Ca ２＋ ) ｃ ・(Y ｎ－ ) ｄ ...Formula (II) [In formula (II), Y ｎ－ represents an anion that serves as a counter ion for the calcium ion. n represents an integer of 1, 2, or 3. c and d each represent an integer of 1, 2, or 3. c, d, and n are in a relationship that satisfies the formula 2c=nd.

4. Calcium ion (a1) is CaCl ２ , CaBr ２ , CaI ２ , Ca(HCO ２ ) ２ , Ca(HCO ３ ) ２ , and Ca(CH ３ COO) ２ 3. The dental composition kit according to claim 1, wherein the calcium compound (a) is selected from the group consisting of:

5. The dental composition kit according to claim 1 or 2, wherein the compound (c) having an acidic group is represented by the following formula (III): １ -((A ｍ－ ) ａ ・(H ＋ ) ｂ ) ｋ ...Formula (III) [In formula (III), R １ and k are as defined in formula (I). ｍ－ represents an m-valent acid anion group derived from the acidic group X. m represents an integer of 1, 2, or 3. a and b represent integers of 1, 2, or 3 such that am=b.

6. The dental composition kit according to claim 1 or 2, wherein the compound (c) having an acidic group is a compound represented by the following formula (IV): ２ -R ３ -OP(=O)(-OH) ２ ...Formula (IV) [In formula (IV), R ２ represents a (meth)acryloyloxy group or hydrogen. ３ represents an alkylene group having 6 to 20 carbon atoms.

7. The dental composition kit according to claim 1 or 2, wherein the zinc ion (d1) is derived from at least one zinc compound (d) selected from the group consisting of ZnO and compounds represented by the following formula (V). (Zn ２＋ ) ｈ ・(P ｒ－ ) ｉ ...Formula (V) [In formula (V), P ｒ－ represents an anion that serves as a counter ion for the zinc ion. r represents an integer of 1, 2, or 3. h and i each represent an integer of 1, 2, or 3. h, i, and r are in a relationship that satisfies the formula 2h=ri.] 8. Zinc ion (d1) is ZnO, ZnCl ２ , Zn(OH) ２ , and ZnF ２ The dental composition kit according to claim 1 or 2, which is derived from at least one zinc compound (d) selected from the group consisting of:

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