Dental quality restorer for dental caries and adhesive material kit for dentistry

Abstract

Provided is a dental caries dentin restorer which is simple and convenient to treat a plurality of teeth at a time, does not discolor at the treatment site, is beautiful, and can prevent and treat caries on the root surface and treat dental caries in the early stage. A dental caries dentin restorer which contains a compound (a) that is represented by formula (I) and has an acidic group, R1-X formula (I) [in formula (I), R1 represents an organic group having 40 or less carbon atoms and having or not having at least one (meth) acryloyloxy group], a zinc ion (b1), water (c), and a hydrophilic solvent (d). And X represents an acidic group. ] The dental caries dentin restorer does not substantially contain a crosslinkable polymerizable monomer.

Description

Technical Field

[0001] The present invention relates to a carious tooth substance restoring agent and a dental adhesive kit. More specifically, the present invention relates to a novel and useful carious tooth substance restoring agent and a dental adhesive kit obtained by using the same. Background Art

[0002] In recent years, the number of teeth remaining in the elderly has increased due to the so-called 8020 movement, which calls for "keeping at least 20 teeth even when you reach 80 years old." However, the gums of the elderly's remaining teeth shrink due to periodontal disease, etc., and the roots of the teeth are exposed. The exposed roots are prone to dental caries. In other words, the increase in the number of teeth remaining in the elderly will lead to the problem of root caries unique to the elderly caused by the exposure of the roots. Therefore, as the elderly population increases, the response to root caries has become an urgent issue.

[0003] Currently, as a treatment method for root caries, filling and restoration based on composite resins and glass ionomer cements are widely used, similar to the treatment of crown caries. However, if caries progresses to below the gingival margin, it becomes extremely difficult to remove the caries and then fill the cavity. In addition, caries sometimes progress to the entire circumference of the root, and the difficulty in repairing such caries is further increased.

[0004] There are many cases where multiple teeth have root caries at the same time, and restoration usually takes time. Therefore, it is a heavy physical and mental burden not only on the dental practitioners who perform the treatment, but also on the patients who receive the treatment.

[0005] From the viewpoint of inhibiting the aggravation of dental caries and preventing the occurrence of dental caries, it is observed that diammine silver fluoride preparations are effective. Diammine silver fluoride preparations are a material that can be easily used because only the liquid preparation is applied to the affected part, but the applied part turns black, so there is still a problem in terms of aesthetics.

[0006] Among the above problems, from the viewpoint of improving the therapeutic effect of filling and restoration using composite resin, non-patent documents 1 and 2 disclose the following photocurable dental adhesive composition, which contains a compound having a phosphate group, a zinc compound, water, a hydrophilic solvent, a cross-linkable polymerizable monomer and a polymerization initiator. The purpose of non-patent document 1 is to impart an antibacterial function to the dental adhesive, and the purpose of non-patent document 2 is to improve the bonding strength function of the dental adhesive.

[0007] It should be noted that Patent Document 1 describes a therapeutic agent for hyperesthesia, which contains a water-soluble phosphate compound and a water-insoluble non-calcium powder in a specified weight ratio; Patent Document 2 describes a toothpaste composition, which contains a specified poorly water-soluble powder, a specified desensitizing agent and water; Patent Document 3 describes an oral composition, which contains a nonionic surfactant and specified alcohols; Patent Document 4 describes an oral care composition, which contains a water-insoluble zinc compound and a compound having a COP bond in an orally acceptable carrier; and Patent Document 5 describes a tooth surface treatment agent, which contains a carboxylic acid, zinc chloride and water.

[0008] However, the techniques described in Non-Patent Documents 1 and 2 and Patent Documents 1 to 5 do not describe restoring caries to a state close to healthy tooth substance, and do not consider the treatment of early caries.

[0009] Prior art literature

[0010] Patent Literature

[0011] Patent Document 1: Japanese Patent Application Laid-Open No. 06-092860

[0012] Patent Document 2: Japanese Patent Application Publication No. 2013-001648

[0013] Patent Document 3: Japanese Patent Application Publication No. 2002-047157

[0014] Patent Document 4: Japanese Patent Application No. 2009-520829

[0015] Patent Document 5: Japanese Patent Application Laid-Open No. 01-090108

[0016] Non-patent literature

[0017] Non-patent literature 1: Journal of the Mechanical Behavior of Biomedical Materials, 100 (2019) 103366

[0018] Non-patent literature 2: Al-Azhar Dental Journal for Girls, 4(3)289-296 Summary of the invention

[0019] Problems to be solved by the invention

[0020] As described above, root caries is a dental disease for which an appropriate treatment method has not yet been established, and new materials suitable for this disease are being sought.

[0021] The present invention has been made in view of the above problems, and an object of the present invention is to provide a caries tooth substance restoring agent which has the convenience of being able to treat a plurality of teeth at a time, does not discolor the treated area, has excellent aesthetics, and can prevent root caries and treat early stage caries.

[0022] Methods used to solve problems

[0023] The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found the following new knowledge: by applying a specific composition containing a compound having an acidic group, a zinc compound, water, and a hydrophilic solvent to a tooth surface, not only decalcified tooth but also healthy tooth can be strengthened in a short period of time. In addition, they have found that the tooth surface coated with the specific composition can obtain caries resistance, and further repeated studies have led to the completion of the present invention.

[0024] That is, the present invention includes the following technical solutions.

[0025] [1] A carious tooth substance restoring agent comprising a compound (a), a zinc ion (b1), water (c) and a hydrophilic solvent (d), wherein the compound (a) is represented by the following formula (I) and has an acidic group.

[0026] R 1 -X···Formula (I)

[0027] [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.]

[0028] The carious tooth substance restoration agent substantially does not contain a cross-linking polymerizable monomer.

[0029] [2] The carious tooth restoration agent according to claim 1, wherein the compound (a) having an acidic group is represented by the following formula (II).

[0030] R 1 -((X m- ) a ·(H + ) b ) k Formula (II)

[0031] [In formula (II), R 1 X has the same meaning as defined in formula (I). m- represents an m-valent acid anion group. m represents an integer of 1, 2 or 3. a and b represent integers of 1, 2 or 3 in the relationship of am=b. k represents an integer of 1 or 2.]

[0032] [3] The carious tooth substance restoring agent according to [1] or [2] above, wherein the compound (a) having an acidic group is a compound represented by the following formula (III).

[0033] R 2 -R 3 -OP(=O)(-OH)2···Formula (III)

[0034] [In formula (III), R 2 represents a (meth)acryloyloxy group or hydrogen. 3 represents an alkylene group having 6 to 20 carbon atoms.]

[0035] [4] The carious tooth restoration agent according to any one of [1] to [3] above, wherein the content of the compound (a) having an acidic group is 10 to 70% by mass relative to the total mass of the compound (a) having an acidic group, water (c) and the hydrophilic solvent (d) (100% by mass).

[0036] [5] The carious tooth substance restoring agent according to any one of [1] to [4] above, wherein the zinc ion (b1) is derived from at least one zinc compound (b) selected from ZnO and a compound represented by the following formula (IV).

[0037] (Zn 2+ ) c ·(Y n- ) d Formula (IV)

[0038] [In formula (II), Y n- represents an anion that serves as a counter ion for zinc ions. n represents an integer of 1, 2 or 3. c and d represent integers of 1, 2 or 3, respectively. c, d and n are in a relationship that satisfies the formula 2c=nd.]

[0039] [6] The carious tooth restoration agent according to any one of [1] to [5] above, wherein the zinc ion (b1) is derived from at least one zinc compound (b) selected from ZnO, ZnCl2, Zn(OH)2 and ZnF2.

[0040] [7] The carious tooth restoration agent according to any one of [1] to [6] above, wherein the content of the zinc compound (b) is 0.3 to 10% by mass relative to 100% by mass of the total mass of the compound having an acidic group (a), water (c) and the hydrophilic solvent (d).

[0041] [8] The carious tooth restoring agent according to any one of [1] to [7] above, wherein the amount of organic compounds other than the compound having an acidic group (a) and the hydrophilic solvent (d) is 5 parts by mass or less per 100 parts by mass of the carious tooth restoring agent.

[0042] [9] A dental adhesive kit comprising the carious tooth restoration agent [A] according to any one of [1] to [8] above and a dental adhesive [B].

[0043] Effects of the Invention

[0044] According to the present invention, a carious tooth texture restoration agent can be provided which can ensure high aesthetics and further strengthen healthy tooth texture by simply applying to tooth surfaces, and can restore tooth texture that has been decalcified and weakened due to caries to a strength closer to that of healthy tooth texture. DETAILED DESCRIPTION

[0045] In the present specification, the "strength" in the case of "strong tooth texture" refers to mechanical strength and resistance to decalcification by acid.

[0046] In addition, in this specification, the upper limit value and the lower limit value of the numerical range (content of each component, the value calculated from each component, each physical property, etc.) can be combined appropriately.

[0047] In addition, in this specification, "agents for restoring carious tooth substance" refers to a dental material that can restore the tooth substance to a state close to healthy tooth substance by applying it to the tooth substance that has been decalcified / fragile due to caries, and is a dental material that can at least restore the initial decalcified tooth substance in the initial stage of caries. "Agents for restoring carious tooth substance" may also have the effect of strengthening tooth substance and preventing tooth substance caries.

[0048] [Caries tooth restoration agent]

[0049] The carious tooth substance restoring agent according to an embodiment of the present invention comprises a compound (a), a zinc ion (b1), water (c) and a hydrophilic solvent (d), wherein the compound (a) is represented by the following formula (I) and has an acidic group.

[0050] R 1 -X···Formula (I)

[0051] [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.]

[0052] The carious tooth substance restoration agent substantially does not contain a cross-linking polymerizable monomer.

[0053] In addition, in this specification, "(meth)acryloyloxy group" is a general term for methacryloyloxy group and acryloyloxy group. The same applies to other similar terms.

[0054] The mechanism by which the effect of the present invention can be obtained by the carious tooth substance restoring agent is not limited thereto, but the present inventors have estimated it as follows.

[0055] By applying the above-mentioned carious tooth restoration agent to the tooth surface, a deposit is formed on the entire tooth surface to which the deposit is applied. It is believed that the deposit is a substance formed by the compound (a) having an acidic group, zinc ions (b1) and inorganic components of the decalcified tooth surface during the process of decalcifying the smear layer and the tooth surface part of the tooth surface by the acidic mixture containing the compound (a) having an acidic group, water (c) and the hydrophilic solvent (d) and penetrating into the tooth, and precipitating and depositing on the tooth surface. It is speculated that the mechanical strength of the tooth is improved by its formation, and further, the anti-caries effect is imparted.

[0056] Generally, in the case of caries with substantial defects, it is necessary to restore the crown shape with a restorative material. In this case, by using the above-mentioned caries tooth substance restoration agent, the tooth substance that has been decalcified / fragile due to caries can be restored to a strength close to that of healthy tooth substance, thereby making the adhesion of the restorative material to the tooth substance more stable and achieving a highly reliable restoration.

[0057] In this specification, the effects of the carious tooth restoration agent on improving the mechanical strength of healthy tooth, improving the mechanical strength of carious tooth dentine, and improving the resistance of healthy tooth to decalcification by acid may be collectively referred to as "tooth strengthening".

[0058] The compositions described in Non-Patent Documents 1 and 2 also contain a compound having an acidic group, a hydrophilic solvent, water, and a zinc compound. However, since the compositions described in Non-Patent Documents 1 and 2 are firmly cured by the action of a photopolymerization initiator, they are designed to further contain a considerable amount of a cross-linking polymerizable monomer in order to achieve the original purpose, i.e., the function as a dental adhesive.

[0059] That is, the compositions described in non-patent documents 1 and 2 are photopolymerizable dental adhesives. It is known that dental adhesives are acidic mixtures, and when applied to tooth surfaces, the smear layer and the surface layer of the tooth surface are decalcified and penetrate into the tooth. On the other hand, non-patent documents 1 and 2 do not describe that deposits are formed on the tooth surface by applying the compositions described in non-patent documents 1 and 2 to the tooth surface. In addition, there is no description that applying the compositions described in non-patent documents 1 and 2 to the tooth surface has the effect of strengthening the tooth.

[0060] It is speculated that the presence of a cross-linkable polymerizable monomer, which is one of the organic compounds, mixed in addition to the compound (a) having an acidic group and the hydrophilic solvent (d) in the compositions described in Non-Patent Documents 1 and 2 inhibits the compound having an acidic group from forming a complex with the zinc compound and the inorganic components of the decalcified tooth, or that a necessary amount of deposit is not formed. As a result, it is speculated that in Non-Patent Documents 1 and 2, no deposit is formed on the tooth surface, and the tooth strengthening effect is not exhibited.

[0061] <Compound (a) having an acidic group>

[0062] The compound (a) having an acidic group represented by the above formula (I) is a compound having an acidic group which, when mixed with water (c) and a hydrophilic solvent (d), produces an acid composition that exhibits an acid etching effect and a primer treatment effect on tooth structure, and is a component that imparts a decalcifying effect and a penetrating effect.

[0063] The compound (a) having an acidic group represented by the above formula (I) is preferably represented by the following formula (II).

[0064] R 1 -((X m- ) a ·(H + ) b ) k Formula (II)

[0065] [In formula (II), R 1 X has the same meaning as defined in the above formula (I). m- represents an m-valent acid anion group. m represents an integer of 1, 2 or 3. a and b represent integers of 1, 2 or 3 in the relationship of am=b. k represents an integer of 1 or 2.]

[0066] Examples of the compound (a) having an acidic group include compounds having at least one acidic group such as a phosphate group, a pyrophosphate group, a thiophosphate group, a phosphonic acid group, a sulfonic acid group, a carboxylic acid group, etc. Specific examples of the compound (a) having an acidic group are listed below.

[0067] Examples of the compound containing a phosphate group include dihydrogen octyl phosphate, dihydrogen decyl phosphate, dihydrogen dodecyl phosphate, dihydrogen tetradecyl phosphate, dihydrogen hexadecyl phosphate, dihydrogen octadecyl phosphate, dihydrogen 2-(meth)acryloyloxyethyl phosphate, dihydrogen 3-(meth)acryloyloxypropyl phosphate, dihydrogen 4-(meth)acryloyloxybutyl phosphate, dihydrogen 5-(meth)acryloyloxypentyl phosphate, dihydrogen 6-(meth)acryloyloxyhexyl phosphate, dihydrogen 7-(meth)acryloyloxyheptyl phosphate, dihydrogen 8-(meth)acryloyloxyoctyl phosphate, dihydrogen 9-(meth)acryloyloxynonyl phosphate, dihydrogen 10-(meth)acryloyloxydecyl phosphate, dihydrogen 11-(meth)acryloyloxyundecyl phosphate, dihydrogen 12-(meth)acryloyloxy dodecyl ester, 16-(meth)acryloyloxyhexadecyl dihydrogen phosphate, 20-(meth)acryloyloxyeicosyl 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, 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, bis[2-(meth)acryloyloxy-(1-hydroxymethyl)ethyl] hydrogen phosphate.

[0068] Examples of the compound containing a pyrophosphate group 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.

[0069] Examples of the compound containing a thiophosphoric acid group include 2-(meth)acryloyloxyethyl dihydrogen thiophosphate, 3-(meth)acryloyloxypropyl dihydrogen thiophosphate, 4-(meth)acryloyloxybutyl dihydrogen thiophosphate, 5-(meth)acryloyloxypentyl dihydrogen thiophosphate, 6-(meth)acryloyloxyhexyl dihydrogen thiophosphate, 7-(meth)acryloyloxyheptyl dihydrogen thiophosphate, 8-(meth)acryloyloxyoctyl 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)acryloyloxyeicosyl dihydrogen thiophosphate.

[0070] Examples of the compound containing a phosphonic acid group include 2-(meth)acryloyloxyethylphenyl phosphonate, 5-(meth)acryloyloxypentyl 3-phosphopropionate, 6-(meth)acryloyloxyhexyl 3-phosphopropionate, 10-(meth)acryloyloxydecyl 3-phosphopropionate, 6-(meth)acryloyloxyhexyl phosphoacetate, and 10-(meth)acryloyloxydecyl phosphoacetate.

[0071] Examples of the sulfonic acid group-containing compound include 2-(meth)acrylamide-2-methylpropanesulfonic acid, styrenesulfonic acid, and 2-sulfoethyl (meth)acrylate.

[0072] Examples of the carboxylic acid group-containing compound include compounds having one carboxyl group in the molecule and compounds having a plurality of carboxyl groups in the molecule.

[0073] Examples of the compound having one carboxyl 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)acryloyloxybenzoic acid, 3-(meth)acryloyloxybenzoic acid, 4-(meth)acryloyloxybenzoic acid, 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.

[0074] Examples of the compound having a plurality of carboxyl 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)acryloyloxytridecane-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.

[0075] The compound (a) having an acidic group may be a compound represented by the following general formula (III).

[0076] R 2 -R 3 -OP(=O)(-OH)2···Formula (III)

[0077] [In formula (III), R 2 represents a (meth)acryloyloxy group or hydrogen. 3 represents an alkylene group having 6 to 20 carbon atoms.]

[0078] Among these compounds (a) having an acidic group, compounds containing a phosphate group or a pyrophosphate group are preferred because they show better deposit formation on tooth tissue, and compounds containing a phosphate group are particularly preferred. Among them, from the viewpoint of showing high tooth decalcification and high deposit formation, more preferred are divalent compounds containing a phosphate group having an alkyl group with 6 to 20 carbon atoms as a main chain in the molecule, or divalent compounds containing a phosphate group having an alkylene group with 6 to 20 carbon atoms as a main chain in the molecule such as the compound represented by the above formula (III), and most preferred are divalent compounds containing a phosphate group having an alkyl group or an alkylene group with 8 to 12 carbon atoms as a main chain in the molecule such as dodecyl dihydrogen phosphate and 10-methacryloyloxydecyl dihydrogen phosphate.

[0079] The compound (a) having an acidic group may be used alone or in combination of two or more. From the viewpoint of easily ensuring the effect of the present invention, the content of the compound (a) having an acidic group is preferably 10% by mass or more, more preferably 15% by mass or more, and further preferably 20% by mass or more relative to the total mass of the compound (a) having an acidic group, water (c) and the hydrophilic solvent (d) in the above-mentioned caries tooth substance restoration agent. In addition, it is preferably 70% by mass or less, more preferably 60% by mass or less. In other words, the content of the compound (a) having an acidic group is preferably 10 to 70% by mass relative to the total mass of the compound (a) having an acidic group, water (c) and the hydrophilic solvent (d) 100% by mass.

[0080] <Zinc ion (b1) and zinc compound (b)>

[0081] The zinc ions (b1) are derived from the zinc compound (b). The zinc compound (b) is dissolved in the compound (a) having an acidic group, thereby containing the zinc ions (b1) in the above-mentioned carious tooth substance restoration agent.

[0082] The zinc ion (b1) is preferably derived from at least one zinc compound (b) selected from the group consisting of ZnO and a compound represented by the following formula (IV).

[0083] (Zn 2+ ) c ·(Y n- ) d Formula (IV)

[0084] [In the above general formula (IV), Y n- represents an anion that serves as a counter ion for zinc ions. n represents an integer of 1, 2 or 3. c and d represent integers of 1, 2 or 3, respectively. c, d and n are in a relationship that satisfies the formula 2c=nd.]

[0085] Specific examples of the zinc compound (b) include at least one zinc compound (b) selected from the group consisting of ZnO, ZnCl 2 , Zn(OH) 2 and ZnF 2 , and ZnO is preferred.

[0086] The zinc compound (b) used in preparing the above-mentioned carious tooth substance restoring agent may be used alone or in combination of two or more thereof. Therefore, the zinc ion (b1) in the carious tooth substance restoring agent may be used alone or in combination of two or more thereof.

[0087] From the viewpoint of easily and well forming a deposit for strengthening tooth substance, the amount of the zinc compound (b) added to the above-mentioned carious tooth substance restoration agent is preferably 0.3% by mass or more, more preferably 0.6% by mass or more, and further preferably 1.0% by mass or more, relative to the total mass (100% by mass) of the compound (a) having an acidic group, water (c), and the hydrophilic solvent (d). In addition, from the viewpoint of suppressing excessive promotion of neutralization of the acidic group of the compound (a) having an acidic group and ensuring good decalcification and penetration, it is preferably 10% by mass or less, more preferably 7.0% by mass or less, and further preferably 5.0% by mass or less. In other words, the content of the zinc compound (b) is preferably 0.3 to 10% by mass relative to the total mass of 100% by mass of the compound (a) having an acidic group, water (c), and the hydrophilic solvent (d).

[0088] In addition, from the same viewpoint, the content of zinc ions (b1) in the above-mentioned carious tooth substance restoration agent is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and further preferably 0.3% by mass or more, relative to the total mass (100% by mass) of the compound (a) having an acidic group, water (c) and the hydrophilic solvent (d), and is preferably 8.0% by mass or less, more preferably 5.6% by mass or less, and further preferably 4.0% by mass or less. In other words, the content of zinc ions (b1) is preferably 0.1 to 8.0% by mass relative to the total mass (100% by mass) of the compound (a) having an acidic group, water (c) and the hydrophilic solvent (d).

[0089] The content of zinc ions (b1) in the carious tooth substance restoring agent can be calculated from the amount of the zinc compound (b) added, or can be calculated from the content of zinc ions (b1) determined by measurement using an ICP emission spectrometer.

[0090] <Water (c)>

[0091] The water (c) preferably does not contain impurities that may cause adverse effects, and is preferably distilled water or ion-exchanged water. The content of the water (c) in the above-mentioned carious tooth substance restoration agent 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 the total mass of the compound (a) having an acidic group, water (c) and the hydrophilic solvent (d) (100% by mass).

[0092] <Hydrophilic Solvent (d)>

[0093] The hydrophilic solvent (d) is 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 soluble in water at 25°C in any proportion.

[0094] The hydrophilic solvent (d) may be a single compound or a mixture of a plurality of compounds.

[0095] Examples of the hydrophilic solvent (d) 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 (those having 9 or more oxyethylene groups), N,N-methacrylate. N-dimethylaminoethyl ester, N-hydroxymethyl (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)acrylamide represented by the following formula (V), etc.

[0096] [Chemistry 1]

[0097]

[0098] [In the above formula (V), R 3 and R 4 Each independently represents an alkyl group having 1 to 3 carbon atoms (such as methyl, ethyl, n-propyl, isopropyl, etc.) which may have a substituent (such as hydroxyl, etc.), R 5 is a hydrogen atom or a methyl group.]

[0099] Among these hydrophilic solvents (d), 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 (V) are more preferred. The hydrophilic solvent (d) may be blended alone or in combination of two or more.

[0100] The hydrophilic solvent (d) functions as a co-solvent of the compound (a) having an acidic group and water (c). The content of the hydrophilic solvent (d) in the above-mentioned carious tooth substance restoration agent 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 the total mass of the compound (a) having an acidic group, water (c) and the hydrophilic solvent (d) (100% by mass).

[0101] <Organic Compounds Other Than Compound (a) Having an Acidic Group and Hydrophilic Solvent (d)>

[0102] The above-mentioned carious tooth substance restoring agent does not substantially contain a cross-linking polymerizable monomer belonging to an organic compound other than the compound (a) having an acidic group and the hydrophilic solvent (d). Specifically, "substantially not containing" here means that the cross-linking polymerizable monomer is 5 parts by mass or less, preferably 3 parts by mass or less in 100 parts by mass of the above-mentioned carious tooth substance restoring agent.

[0103] The crosslinkable polymerizable monomer is a hydrophobic crosslinkable polymerizable monomer having no acidic group, and examples thereof include aromatic difunctional monomers, aliphatic difunctional monomers, and trifunctional or higher-functional monomers.

[0104] The carious tooth restoration agent according to the embodiment of the present invention does not substantially contain a cross-linkable polymerizable monomer, thereby preventing the compound (a) having an acidic group, zinc ions (b1) and inorganic components of decalcified tooth from being hindered in forming a complex, and can promote the formation of deposits based thereon.

[0105] Examples of the aromatic difunctional 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)acryloyloxy propane, 2-(4-(meth)acryloxydiethoxyphenyl)-2-(4-(meth)acryloxyethoxyphenyl)propane, 2-(4-(meth)acryloxydiethoxyphenyl)-2-(4-(meth)acryloxytriethoxyphenyl)propane, 2-(4-(meth)acryloxydipropoxyphenyl)-2-(4-(meth)acryloxytriethoxyphenyl)propane, 2,2-bis(4-(meth)acryloxypropoxyphenyl)propane, 2,2-bis(4-(meth)acryloxyisopropoxyphenyl)propane, and the like.

[0106] 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, butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and 1,10-decanediol di(meth)acrylate. (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, N-(2-(2-methacryloyloxyethoxy)ethyl)acrylamide, and the like.

[0107] Examples of the trifunctional or higher-functional monomer 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-diacryloxy-2,2,6,6-tetra(meth)acryloyloxymethyl-4-oxyheptane.

[0108] The above-mentioned decayed tooth substance restoring agent preferably does not substantially contain organic compounds other than the compound (a) having an acidic group and the hydrophilic solvent (d) including the above-mentioned cross-linkable polymerizable monomer. Specifically, "substantially not containing" here means that in 100 parts by mass of the above-mentioned decayed tooth substance restoring agent, the organic compounds other than the compound (a) having an acidic group and the hydrophilic solvent (d) are 5 parts by mass or less, preferably 3 parts by mass or less.

[0109] As the organic compound other than the compound (a) having an acidic group and the hydrophilic solvent (d) and other than the above-mentioned crosslinkable polymerizable monomer, there can be mentioned:

[0110] 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;

[0111] Polymerization accelerators such as aldehydes, thiol compounds, and aminobenzoate compounds;

[0112] Antimicrobial substances such as cetylpyridinium chloride, benzalkonium chloride, (meth)acryloyloxydodecylpyridinium bromide, (meth)acryloyloxyhexadecylpyridinium chloride, (meth)acryloyloxydecyl ammonium chloride, triclosan, 12-methacryloyloxydodecylpyridinium bromide, etc.

[0113] 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.

[0114] Examples of the (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.

[0115] Examples of the α-diketones used as the photopolymerization initiator include diacetyl, benzyl, camphorquinone, 2,3-pentanedione, 2,3-octanedione, 9,10-phenanthrenequinone, 4,4′-hydroxybenzene, and acenaphthenequinone.

[0116] Specific examples of aldehydes used as the polymerization accelerator include terephthalaldehyde, benzaldehyde derivatives, etc. Examples of benzaldehyde derivatives include dimethylaminobenzaldehyde, p-methoxybenzaldehyde, p-ethoxybenzaldehyde, and p-n-octyloxybenzaldehyde.

[0117] Specific examples of the thiol compound used as the polymerization accelerator include 2-mercaptobenzoxazole, decanethiol, 3-mercaptopropyltrimethoxysilane, and thiobenzoic acid.

[0118] Specific examples of the aminobenzoate compounds used as the above-mentioned 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.

[0119] <Other ingredients>

[0120] The above-mentioned decayed tooth substance restoring agent may further contain one or more other components. Examples of the other components include pH adjusters, polymerization inhibitors, ultraviolet absorbers, thickeners, colorants (dyes, pigments, etc.), fluorescent agents, fragrances, etc. In addition, the above-mentioned decayed tooth substance restoring agent may include, as the above-mentioned other components, fluoride ion releasing substances such as sodium fluoride, potassium fluoride, sodium monofluorophosphate, lithium fluoride, strontium fluoride, ytterbium fluoride, etc. In addition, the above-mentioned decayed tooth substance restoring agent may include, for example, metal compounds such as calcium hydroxide, calcium chloride, silver oxide, aluminum hydroxide, etc.

[0121] The amount of other components added is not particularly limited as long as the necessary effects can be obtained. From the viewpoint of easily ensuring sufficient reinforcement of tooth substance and effectiveness of treatment of early caries, the amount of other components added is preferably 0.01 to 1 part by mass, more preferably 0.05 to 0.5 part by mass, and even more preferably 0.07 to 0.3 part by mass in 100 parts by mass of the carious tooth substance restoring agent.

[0122] However, when the other component is an organic compound, the amount thereof blended is 5 parts by mass or less, more preferably 3 parts by mass or less, based on 100 parts by mass of the carious tooth substance restoring agent.

[0123] The carious tooth substance restoring agent according to one embodiment of the present invention may contain calcium ions as the other component as long as the effect of the present invention is exhibited, but preferably contains substantially no calcium ions from the viewpoint of more easily exhibiting the effect of the present invention.

[0124] It can be inferred that by making the above-mentioned carious tooth substance restoring agent substantially free of calcium ions, in the process of forming the deposit caused by the above-mentioned carious tooth substance restoring agent, the interference of calcium ions can be reduced for at least one of the action of precipitation through complexation of the compound (a) having an acidic group, zinc ions (b1) and the inorganic components of the decalcified tooth, and the action of deposition on the tooth surface, so that the above-mentioned deposit can be formed more effectively.

[0125] The calcium ions are derived from a calcium compound. The calcium compound is dissolved by the compound (a) having an acidic group, thereby containing calcium ions in the carious tooth substance restoring agent.

[0126] The calcium ions are derived from, for example, at least one calcium compound selected from the group consisting of CaO and a compound represented by the following formula (VI).

[0127] (Ca 2+ ) e ·(Y p- ) f Formula (VI)

[0128] [In the above general formula (VI), Y n- represents an anion that serves as a counter ion for calcium ions. p represents an integer of 1, 2 or 3. e and f represent integers of 1, 2 or 3, respectively. e, f and p are in a relationship that satisfies the formula 2e=pf.]

[0129] As a more specific calcium compound, at least one calcium compound selected from CaO, CaCl 2 , Ca(OH) 2 and CaF 2 can be exemplified.

[0130] Here, specifically, "substantially free of" calcium ions means that the content of calcium ions in 100% by mass of the above-mentioned carious tooth substance restoring agent is 5% by mass or less, preferably 3% by mass or less, more preferably 1% by mass or less, further preferably 0.1% by mass or less, and further preferably 0.05% by mass or less. In other words, in this specification, "substantially free of calcium ions" means that the content of calcium ions in 100% by mass of the carious tooth substance restoring agent is 0 to 5% by mass, preferably 0 to 3% by mass, more preferably 0 to 1% by mass, further preferably 0 to 0.1% by mass, and further preferably 0 to 0.05% by mass.

[0131] In the present specification, the content of calcium ions in the carious tooth substance restoring agent can be calculated from the amount of the calcium compound that generates calcium ions, or can be determined by measurement using an ICP emission spectrometer.

[0132] [Method for producing a carious tooth substance restoring agent]

[0133] In the method for producing a carious tooth restoration agent according to an embodiment of the present invention, the compound (a) having an acidic group, the zinc compound (b), water (c) and the hydrophilic solvent (d) may be added in any order, and the carious tooth restoration agent may be obtained by finally preparing a liquid mixed composition containing the compound (a) having an acidic group, water (c) and the hydrophilic solvent (d) in which the zinc compound (b) as a solid component is dissolved.

[0134] [Use of carious tooth restoration agent]

[0135] The above-mentioned carious tooth substance restoring agent can be supplied in the form of a one-component liquid, and can be applied to the tooth substance using a cotton ball, a small sponge piece, a small pen, an application brush, etc. After application, if necessary, air is blown using a three-way syringe, etc. to dry the evaporated components, thereby completing the treatment. Since it is a simple surgical procedure, even when treating multiple teeth, the pressure on the operator and the patient is slight.

[0136] The tooth strengthening effect brought about by the decayed tooth substance restoring agent according to the embodiment of the present invention is particularly remarkable on dentin, and therefore, the decayed tooth substance restoring agent can be preferably used as a "dentin strengthening agent".

[0137] In addition, the carious tooth substance restoring agent according to the embodiment of the present invention can be suitably used for preventing the onset of caries, inhibiting the progression of initial caries, inhibiting secondary caries, and inhibiting dentin hyperesthesia.

[0138] [Dental bonding material kit]

[0139] When the carious tooth restoration agent is the carious tooth restoration agent [A], the dental adhesive kit according to the embodiment of the present invention includes the carious tooth restoration agent [A] and the dental adhesive [B].

[0140] As the dental adhesive material [B], there is no particular limitation, and various known dental adhesive materials can be used as the dental adhesive material. The dental adhesive material [B] is generally an adhesive composition comprising an acidic component and water, and further comprises a polymerizable monomer, a polymerization initiator, a solvent, and other compounding agents as required. As a particularly preferred dental adhesive material [B], the following dental adhesive materials can be listed, which comprise a (meth) acrylic polymerizable monomer containing an acidic group as described in International Publication Gazette No. 2013 / 145621, International Publication Gazette No. 2015 / 190099, etc., a water-soluble polymerizable monomer and a polymerization initiator. The dental adhesive material [B] can be a single-component material that can be used directly, or it can be a two-component material that is used by mixing two materials divided into A material and B material immediately before use.

[0141] Examples of commercially available dental adhesives [B] include dental adhesives "CLEARFIL (registered trademark) Universal Bond QuickER" manufactured by Kuraray Noritake Dental Co., Ltd.

[0142] In the dental adhesive kit, the decayed tooth restoration agent [A] contains the above-mentioned components (a) to (d) and does not substantially contain organic compounds other than components (a) and (d). Therefore, by applying it to the treatment site of the tooth, it can achieve the reinforcement of the tooth and the repair of the initial decalcified tooth. On this basis, by supplying the dental adhesive [B] to the surface of the decayed tooth restoration agent [A], the filling material, covering material, etc. such as composite resin further supplied thereafter can be firmly bonded, thereby making it possible to repair the tooth well. In addition, these operations can be completed by the simple process of at least applying the decayed tooth restoration agent [A], and high aesthetics can also be ensured.

[0143] The present invention includes various combinations of the above-mentioned technical features within the scope of the technical concept of the present invention as long as the effects of the present invention are exhibited.

[0144] Example

[0145] Hereinafter, the carious tooth substance restoring agent and the dental adhesive material kit of the present invention will be specifically described using examples, but the carious tooth substance restoring agent and the dental adhesive material kit of the present invention are not limited to the following examples.

[0146] [Preparation of test samples for dentin tensile test (healthy dentin)]

[0147] The labial surface of the front teeth of the mandibular teeth of the cattle was ground with #80 silicon carbide paper (manufactured by Nippon Kenshi Co., Ltd.) under running water to expose the flat surface of the dentin. Then, the lingual surface was ground in the same way to obtain plate-shaped dentin. The obtained plate-shaped dentin was ground with #1000 silicon carbide paper (manufactured by Nippon Kenshi Co., Ltd.) under running water until the thickness reached 1 mm. Then, the 1 mm thick dentin was cut into 1 mm wide pieces using the automatic precision cutting machine IsoMet (manufactured by BUEHLER) to produce a prismatic healthy dentin sample with a thickness of 1 mm × a width of 1 mm × a length of about 15 mm.

[0148] [Preparation of test piece for dentin tensile test (caries model dentin)]

[0149] A healthy dentin sample molded into a prism shape of 1 mm thick × 1 mm wide × about 15 mm long was immersed in 0.5 M acetate buffer (pH 4.6) at 37°C for 24 hours to prepare a prism-shaped carious tooth model dentin sample of 1 mm thick × 1 mm wide × about 15 mm long.

[0150] [Determination of tensile strength of healthy dentin and caries model dentin]

[0151] Healthy and carious tooth model dentin samples, each shaped into a prismatic shape of 1 mm thick, 1 mm wide, and about 15 mm long, were fixed to a fixture for micro-tensile testing using a cyanoacrylate adhesive. The tensile strength of dentin was measured using a small tabletop universal testing machine (manufactured by Shimadzu Corporation) at a slide speed of 1 mm / min. Five samples were measured for each condition, and the average value was set as the tensile strength.

[0152] The tensile strength of healthy dentin is 109MPa, and the tensile strength of the dentin in the caries model is 44MPa.

[0153] The abbreviations of various components used in Examples and Comparative Examples are as follows.

[0154] [Compound having an acidic group (a)]

[0155] MHP: 6-methacryloyloxyhexyl dihydrogen phosphate

[0156] MDP: 10-methacryloyloxydecyl dihydrogen phosphate

[0157] M12P: 12-methacryloyloxydodecyl dihydrogen phosphate

[0158] 4-MET: 4-Methacryloyloxyethyl trimellitate

[0159] M4P: 4-methacryloyloxybutyl dihydrogen phosphate

[0160] [Hydrophilic solvent (d)]

[0161] HEMA: 2-Hydroxyethyl Methacrylate

[0162] DEAA: N,N-diethylacrylamide (compound represented by formula (V))

[0163] [Organic compound other than the compound having an acidic group (a) and the hydrophilic solvent (d)]

[0164] CPC: Cetylpyridinium chloride

[0165] Bis-GMA: 2,2-bis[4-(3-methacryloyloxy-2-hydroxypropyloxy)phenyl]propane

[0166] CQ: DL-Camphorquinone

[0167] EDMB: ethyl 4-(N,N-dimethylamino)benzoate

[0168] [Preparation and evaluation of carious dentine restoring agent]

[0169] <Examples 1 to 11 and Comparative Examples 1 to 4>

[0170] The carious tooth substance restoring agents of each example and each comparative example were prepared by mixing the materials according to the ratios described in Table 1. Samples were prepared using each composition according to the following procedures, and the samples were measured according to the following procedures. It should be noted that, regarding Comparative Example 1, since the composition was phase-separated, the tensile strength could not be measured.

[0171] (Tensile strength of healthy dentin after treatment [X])

[0172] Using a smear brush, various compositions were applied to healthy dentin samples formed into a prism shape of 1 mm in thickness, 1 mm in width, and about 15 mm in length, and air blast treatment was performed. Various samples were fixed to a fixture for micro-tensile testing using a cyanoacrylate adhesive. The tensile strength of dentin was measured using a small table-top universal testing machine (manufactured by Shimadzu Corporation) at a slide speed of 1 mm / min. For each condition, five samples were measured, and the arithmetic mean was defined as "tensile strength [X] after treatment of healthy dentin".

[0173] (Tensile strength of healthy dentin treated with artificial caries [Y])

[0174] Various compositions were applied to healthy dentin samples formed into a prism shape of 1 mm in thickness × 1 mm in width × about 15 mm in length using a smear brush, and air blowing treatment was immediately performed. Thereafter, various samples were immersed in 0.5 M acetic acid buffer (pH 4.6) at 37°C for 24 hours to form an artificial caries treatment group. Various samples were fixed to a fixture for a micro tensile test using a cyanoacrylate adhesive. The tensile strength of dentin was measured using a small table-top universal testing machine (manufactured by Shimadzu Corporation) at a slider speed of 1 mm / min. For each condition, five samples were measured, and the arithmetic mean was set as "tensile strength [Y] after healthy dentin was treated and then artificial caries were treated".

[0175] (Tensile strength of treated dentin in caries model [Z])

[0176] Using a smear brush, various compositions were applied to a prismatic caries model dentin sample with a thickness of 1 mm, a width of 1 mm, and a length of about 15 mm, and air blast treatment was immediately performed. Various samples were fixed to a fixture for a micro tensile test using a cyanoacrylate adhesive. The tensile strength of the dentin was measured using a small table-top universal testing machine (manufactured by Shimadzu Corporation) at a slide speed of 1 mm / min. For each condition, five samples were measured, and the arithmetic mean value was set as the "tensile strength [Z] of the caries model dentin after treatment".

[0177] The results of "tensile strength [X] after treatment of healthy dentin", "tensile strength [Y] after treatment of healthy dentin and then artificial caries treatment", and "tensile strength [Z] after treatment of caries model dentin" are summarized in Table 1. In addition, the ratio of [X] to "tensile strength of healthy dentin (109 MPa)" and the ratio of [Y] to "tensile strength of healthy dentin (109 MPa)" are summarized in Table 1. The ratio of [Z] to "tensile strength of caries model dentin (44 MPa)" is also summarized in Table 1.

[0178] [Table 1]

[0179]

[0180] According to the results in Table 1, it can be seen that the treatment with the carious tooth restoration agent containing the above-mentioned components (a) to (d) and substantially containing no organic compounds other than components (a) and (d) has the function of improving the tensile strength of healthy dentin. In addition, it can be seen that the healthy dentin treated with the carious tooth restoration agent containing the above-mentioned components (a) to (d) and substantially containing no organic compounds other than components (a) and (d) maintains its strength even when artificial caries treatment is applied, and obtains caries resistance. It can also be seen that the carious tooth restoration agent containing the above-mentioned components (a) to (d) and substantially containing no organic compounds other than components (a) and (d) is used to treat the carious tooth model dentin whose tensile strength is reduced by artificial caries treatment, thereby restoring the tensile strength.

[0181] In addition, compared with the carious tooth restoration agents of Examples 9 and 11 obtained by using the compound (a) that does not conform to the above formula (III), and the carious tooth restoration agent of Example 10 in which the compound represented by the above formula (III) is used as the compound (a) but contains an organic compound other than the compound (a) and the hydrophilic solvent (d), the carious tooth restoration agents of Examples 1 to 8 in which the compound represented by the above formula (III) is used as the compound (a) have larger values ​​of "the ratio of the tensile strength after the healthy dentin is treated to the tensile strength of the untreated healthy dentin", "the ratio of the tensile strength of the healthy dentin treated and then subjected to artificial caries treatment to the tensile strength of the untreated healthy dentin", and "the tensile strength of the carious model dentin after the carious model dentin is treated to the tensile strength of the carious model dentin".

[0182] On the other hand, according to the results of Comparative Example 2 prepared according to the compositions used in Non-Patent Documents 1 and 2, in which 33 parts by mass of an organic compound other than the compound having an acidic group (a) and the hydrophilic solvent (d) were contained in 100 parts by mass of the composition, and Comparative Example 3 prepared by adding 10 parts by mass of an organic compound other than the compound having an acidic group (a) and the hydrophilic solvent (d) to 90 parts by mass of the composition of Example 2, it was found that the function of improving the tensile strength of healthy dentin was not observed when the composition containing the organic compound other than the compound having an acidic group (a) and the hydrophilic solvent (d) in an amount exceeding 5 parts by mass in 100 parts by mass of the composition was treated. It was also found that the carious tooth restoration agents of Comparative Examples 2 and 3 did not obtain resistance to artificial caries treatment, and the tensile strength of the carious model dentin whose tensile strength was reduced by artificial caries treatment was not restored.

[0183] In addition, the results of Comparative Example 4 show that the function of improving the tensile strength of healthy dentin was not observed when the composition using the zinc compound (b) as the other metal compound was used for treatment. In addition, it was found that the carious dentin restoration agent of Comparative Example 4 did not obtain resistance to artificial caries treatment, and did not restore the tensile strength of carious model dentin whose tensile strength was reduced by artificial caries treatment.

[0184] [Combined use of carious tooth restoration agent and dental adhesive]

[0185] <Example 12>

[0186] It is assumed that the above-mentioned carious tooth substance restoring agent is applied to the treatment of the tooth surface in the filling and repair of the carious cavity, and a bonding test is carried out on the artificial carious tooth dentine. That is, first, the labial surface of the bovine mandibular front tooth is ground with #80 silicon carbide paper (manufactured by Nippon Kenshi Co., Ltd.) under running water to obtain a sample in which the flat surface of the dentine is exposed. The obtained sample is further ground with #1000 silicon carbide paper (manufactured by Nippon Kenshi Co., Ltd.) under running water. After grinding, the surface water is blown off to dry.

[0187] Next, the tooth surface except the central part (4 mm × 4 mm) of the exposed surface of the target dentin was coated with nail polish, and then immersed in 0.5M acetic acid buffer (pH 4.6) at 37°C for 24 hours to form a caries model dentin on the exposed surface of the dentin. The caries model dentin prepared as above was washed under running water and dried by blowing off the surface water. An adhesive tape with a circular hole of 3 mm in diameter and a thickness of about 150 μm was pasted on the smooth surface (the part where the caries model dentin was formed) after drying to limit the bonding area.

[0188] Using an applicator, the carious tooth substance restoration agent prepared in the above-mentioned Example 1 was applied to the above-mentioned circular hole, and then the surface was immediately blown to dry. Next, a dental adhesive (manufactured by Kuraray Noritake Dental Co., Ltd., trade name "CLEARFIL (registered trademark) Universal Bond QuickER") was applied to the above-mentioned circular hole using a smear brush, and after wiping for 10 seconds, the surface was blown to dry until the fluidity of the applied dental adhesive disappeared. Next, a dental LED light irradiator (manufactured by MORITA, trade name "PenCure 2000") was used to irradiate light for 3 seconds, thereby curing the applied dental adhesive.

[0189] The surface of the cured product of the obtained dental adhesive material was filled with a dental filling composite resin (manufactured by Kuraray Noritake Dental Co., Ltd., trade name "CLEARFIL (registered trademark) AP-X") and covered with a release film (polyester). Next, a carrier sheet was placed on the release film and pressed, thereby smoothing the coated surface of the dental filling composite resin. Next, the dental filling composite resin was irradiated with light for 20 seconds using a dental LED light irradiator (manufactured by MORITA, trade name "PenCure 2000") through the release film to cure the dental filling composite resin.

[0190] Using a commercially available dental resin cement (manufactured by Kuraray Noritake Dental Co., Ltd., trade name "PANAVIA (registered trademark) 21"), one end face (circular cross section) of a stainless steel cylindrical rod (diameter 7 mm, length 2.5 cm) was bonded to the surface of the cured product of the composite resin for dental filling obtained. After bonding, the sample was allowed to stand at room temperature for 30 minutes and then immersed in distilled water to obtain a bonding test sample. Five bonding test samples were prepared and allowed to stand in a thermostat maintained at 37°C for 24 hours while immersed in distilled water.

[0191] The tensile bond strength was measured by using a universal testing machine (manufactured by Shimadzu Corporation) with the slide speed set to 2 mm / min. The arithmetic mean of the obtained values ​​was set as the tensile bond strength. The tensile bond strength was 19 MPa. The results are shown in Table 2.

[0192] <Comparative Example 5>

[0193] The tensile bonding strength of the dental adhesive material to the dentin of the carious tooth model was measured by performing the same operation as in Example 12 except that the operation of "applying the carious tooth substance restoration agent prepared in Example 1 to the circular hole using a smear brush and then immediately blowing air to the surface to dry" was omitted. The tensile bonding strength was 9 MPa. The results are shown in Table 2.

[0194] [Table 2]

[0195] Table 2

[0196]

[0197] According to the results of Example 12 and Comparative Example 5 shown in Table 2, it can be seen that the dental adhesive material has a greater advantage in tensile bonding strength to the caries model dentin treated with the caries tooth restoration agent containing the above-mentioned components (a) to (d) and substantially containing no organic compounds other than components (a) and (d), compared with the tensile bonding strength to the untreated caries model dentin.

[0198] [Influence on tooth color tone]

[0199] <Example 13>

[0200] The composition of Example 1 was applied to the root of the bovine mandibular front teeth using a coating brush and air was blown. After being immersed in distilled water and stored at 37° C. for 24 hours, the applied area was visually observed, and no change in color tone was observed. The results are shown in Table 3.

[0201] <Comparative Example 6>

[0202] According to the usage and dosage described in the manual, the diammine silver fluoride preparation "SAFORIDE Liquid Dental 38%" (BEE BRAND MEDICO DENTAL) was applied to the root of the bovine mandibular front teeth. After being immersed in distilled water and stored at 37°C for 24 hours, the applied part was visually observed, and no obvious change in color to brown was observed. The results are shown in Table 3.

[0203] [Table 3]

[0204] Table 3

[0205]

[0206] From the comparison between Example 13 and Comparative Example 6 shown in Table 3, it is clear that the caries tooth substance restoration agent comprising the above-mentioned components (a) to (d) and substantially containing no organic compound other than components (a) and (d) does not have the color change of the applied part to black or brown that occurs when using the diammine silver fluoride preparation, and can ensure high aesthetics.

[0207] Industrial Applicability

[0208] The carious tooth substance restoring agent of the present invention ensures high aesthetics by simple handling, and realizes strengthening of tooth substance and restoration of initially decalcified tooth substance, and therefore can be particularly suitably used for preventive treatment of root caries and restorative treatment of initial caries.

Claims

1. A carious tooth substance restoring agent comprising a compound (a), a zinc ion (b1), water (c) and a hydrophilic solvent (d), wherein the compound (a) is represented by the following formula (I) and has an acidic group. R 1 -X···Formula (I) In formula (I), R 1 represents an organic group having 40 or less carbon atoms and having or not having at least one (meth)acryloyloxy group; X represents an acidic group, The carious tooth substance restoration agent substantially does not contain a cross-linking polymerizable monomer.

2. The carious tooth substance restoring agent according to claim 1, wherein The compound (a) having an acidic group is represented by the following formula (II): R 1 -((X m- ) a ·(H + ) b ) k Formula (II) In formula (II), R 1 The same meaning as defined in formula (I); X m- represents an m-valent acid anion group; m represents an integer of 1, 2 or 3; a and b represent integers of 1, 2 or 3 in the relationship of am=b; and k represents an integer of 1 or 2.

3. The carious tooth substance restoring agent according to claim 1 or 2, wherein The compound (a) having an acidic group is a compound represented by the following formula (III): R 2 -R 3 -OP(=O)(-OH)2···Formula (III) In formula (III), R 2 represents a (meth)acryloyloxy group or hydrogen; R 3 It represents an alkylene group having 6 to 20 carbon atoms.

4. The carious tooth substance restoring agent according to any one of claims 1 to 3, wherein The content of the compound having an acidic group (a) is 10 to 70% by mass based on 100% by mass of the total mass of the compound having an acidic group (a), water (c) and the hydrophilic solvent (d).

5. The carious tooth substance restoring agent according to any one of claims 1 to 4, wherein The zinc ion (b1) is derived from at least one zinc compound (b) selected from ZnO and a compound represented by the following formula (IV), (Zn 2+ ) c ·(Y n- ) d ··· Formula (IV) In formula (IV), Y n- represents an anion that serves as a counter ion for zinc ion; n represents an integer of 1, 2 or 3; c and d represent integers of 1, 2 or 3, respectively; c, d and n are in a relationship that satisfies the formula 2c=nd.

6. The carious tooth substance restoring agent according to any one of claims 1 to 5, wherein The zinc ions (b1) are derived from at least one zinc compound (b) selected from the group consisting of ZnO, ZnCl2, Zn(OH)2 and ZnF2.

7. The carious tooth substance restoring agent according to any one of claims 1 to 6, wherein The content of the zinc compound (b) is 0.3 to 10% by mass based on 100% by mass of the total mass of the compound having an acidic group (a), water (c) and the hydrophilic solvent (d).

8. The carious tooth substance restoring agent according to any one of claims 1 to 7, wherein In 100 parts by mass of the carious tooth substance restoring agent, the amount of organic compounds other than the compound (a) having an acidic group and the hydrophilic solvent (d) is 5 parts by mass or less. 9 . A dental adhesive kit comprising the carious tooth substance restoring agent [A] according to claim 1 and a dental adhesive [B].

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