Dental composition

Abstract

To provide a dental composition that achieves both of an X-ray contrast property and storage stability.SOLUTION: A dental composition comprises an acidic component, and at least one lanthanoid fluoride powder selected from the group consisting of fluoride powders of lanthanoid with an atomic number of 66 or smaller.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] When a dental material made of a dental composition is used to perform a prosthesis in the oral cavity, the dental composition is required to have radiographic contrast (opacity) so that the position of the material can be confirmed.

[0003] Known substances that exhibit X-ray contrast properties include, for example, ytterbium trifluoride (see, for example, Patent Document 1) and barium glass (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 7-76164 [Patent Document 2] Japanese Patent Application Laid-Open No. 2000-102548 Summary of the Invention [Problem to be solved by the invention]

[0005] However, some dental compositions contain acidic components, and when the acidic components and ytterbium trifluoride or barium glass are present in the same composition, a reaction occurs during storage, making it impossible to use the composition properly, posing a storage stability problem.

[0006] An object of the present invention is to provide a dental composition that is both radiopaque and stable in storage. [Means for solving the problem]

[0007] A dental composition according to one embodiment of the present invention contains an acidic component and at least one lanthanoid fluoride powder selected from the group consisting of lanthanoid fluoride powders having an atomic number of 66 or less.The acidic component contains a polycarboxylic acid. . [Effects of the Invention]

[0008] According to one aspect of the present invention, a dental composition that is both radiopaque and stable in storage can be provided. DETAILED DESCRIPTION OF THE INVENTION

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

[0010] The dental composition according to this embodiment contains an acidic component and a lanthanoid fluoride powder.

[0011] In this specification, the dental composition refers to a composition used as a dental material.

[0012] The acidic component contained in the dental composition of this embodiment is a component that has an acid group and becomes acidic (pH less than 7.0) when dissolved in water. The acidic component is not particularly limited, and inorganic acids and organic acids can be used.

[0013] Examples of inorganic acids include phosphoric acid, sulfuric acid, hydrochloric acid, nitric acid, etc. Among these, phosphoric acid is preferred from the viewpoint of safety for the human body.

[0014] Examples of organic acids include monocarboxylic acids such as formic acid, acetic acid, and benzoic acid, and derivatives of these acids; dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, tartaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, sorbic acid, phthalic acid, and terephthalic acid, and derivatives of these acids; tricarboxylic acids such as hemimelanic acid, trimellitic acid, trimesic acid, agric acid, citric acid, and 1,2,3-propanetricarboxylic acid, and derivatives of these acids; multicarboxylic acids such as pyromellitic acid and mellitic acid, and derivatives of these acids; and polycarboxylic acids such as poly(meth)acrylic acid, and derivatives of these acids, as well as mixtures thereof.

[0015] Among these, polycarboxylic acids are preferred from the viewpoint of high polymerizability and improving the filling property or adhesiveness of the dental composition. Furthermore, it is preferred to contain tartaric acid as an acidic component from the viewpoint of mitigating the oxidation reaction of the lanthanoid fluoride powder in the dental composition.

[0016] The polycarboxylic acid is not particularly limited, but examples thereof include homopolymers and copolymers of α-β unsaturated monocarboxylic acids or α-β unsaturated dicarboxylic acids.

[0017] Examples of the α-β unsaturated monocarboxylic acid or α-β unsaturated dicarboxylic acid that constitutes the homopolymer or copolymer include acrylic acid, methacrylic acid, 2-chloroacrylic acid, 3-chloroacrylic acid, aconitic acid, mesaconic acid, maleic acid, itaconic acid, fumaric acid, glutaconic acid, and citraconic acid.

[0018] These polycarboxylic acids may be used alone or in combination of two or more. Among these polycarboxylic acids, polyacrylic acid and polymethacrylic acid are preferred, and polyacrylic acid is more preferred, from the viewpoint of further improving the filling property or adhesiveness of the dental composition.

[0019] The weight average molecular weight of the polycarboxylic acid is not particularly limited, but is preferably from 5000 to 40000. The polycarboxylic acid is usually blended into the liquid component, but may also be blended into the powder component.

[0020] The content of the acidic component is not particularly limited. The content of the acidic component in the dental composition is, for example, 1% by mass or more and 50% by mass or less, preferably 7% by mass or more and 40% by mass or less, and more preferably 10% by mass or more and 35% by mass or less. When the content of the acidic component in the dental composition is 1% by mass or more and 50% by mass or less, the dental composition can be made into a paste, which makes it easy to handle as a dental composition.

[0021] The lanthanoid fluoride powder contained in the dental composition of this embodiment is at least one lanthanoid fluoride powder selected from the group consisting of lanthanoid fluoride powders having atomic numbers of 66 or less.

[0022] In this specification, the term "lanthanoid fluoride powder" refers to a lanthanoid fluoride in the form of a powder (or powder). When the lanthanoid fluoride in the dental composition is in the form of a powder, the lanthanoid fluoride can be easily incorporated into the dental composition.

[0023] The particle size of the lanthanide fluoride powder is 500 μm or less, preferably 0.01 μm to 150 μm, more preferably 0.05 μm to 100 μm, and even more preferably 0.1 μm to 25 μm. Here, particle size refers to the average particle size defined by the median diameter (d50).

[0024] When the particle size of the lanthanide fluoride powder is 500 μm or less, the decrease in strength of the hardened dental composition is suppressed, and when it is 150 μm or less, precipitation and liquid separation can be prevented. Furthermore, when the particle size of the lanthanide fluoride powder is 100 μm or less, the filling property and handling property of the dental composition can be improved, and when it is 25 μm or less, when it is incorporated into a cementing material, lifting of the prosthesis due to an excessively thick coating can be prevented.

[0025] Lanthanides with atomic numbers below 66 are lanthanides with atomic numbers between 57 and 66. Specifically, they are La (lanthanum), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pr), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), and dysprosium (Dy).

[0026] These fluoride powders of lanthanoids having atomic numbers of 66 or less may be used alone or in combination of two or more.

[0027] Among these, fluoride powder of at least one lanthanoid selected from lanthanum, cerium, praseodymium, and neodymium (lanthanum fluoride, cerium fluoride, praseodymium fluoride, and neodymium fluoride) is preferred from the viewpoint of high acid resistance and high X-ray contrast in the dental composition. Furthermore, lanthanum fluoride, cerium fluoride, and neodymium fluoride are more preferred from the viewpoint of the production cost of the dental composition.

[0028] The content of the lanthanoid fluoride powder is not particularly limited and may be, for example, 1% by mass to 90% by mass, preferably 5% by mass to 75% by mass, and more preferably 10% by mass to 45% by mass in the dental composition.

[0029] When the content of the lanthanoid fluoride powder in the dental composition is 1% by mass or more, the effect of the lanthanoid fluoride powder as an X-ray contrast agent is enhanced. Also, when the content of the lanthanoid fluoride powder in the dental composition is 90% by mass or less, the blending amounts of other components in the dental composition can be ensured, and the physical properties of the dental composition as a whole can be improved.

[0030] The mass ratio of the lanthanide fluoride powder to the acidic component is not particularly limited, but is, for example, 1 mass % to 400 mass %, preferably 1 mass % to 300 mass %, and more preferably 10 to 200 mass %.

[0031] When the mass ratio of the lanthanoid fluoride powder to the acidic component is 1% by mass or more, the effect of the lanthanoid fluoride powder as an X-ray contrast agent is enhanced, and when the mass ratio of the lanthanoid fluoride powder to the acidic component is 400% by mass or less, the amount of other components, including the acidic component, can be ensured, improving the physical properties of the dental composition.

[0032] When barium glass, which provides X-ray contrast, or a lanthanide fluoride with an atomic number greater than 66 (e.g., ytterbium fluoride) is used in a dental composition containing an acidic component, it reacts with the acidic component and hardens after a certain period of storage, rendering it unusable. Furthermore, even when glass containing lanthanum, cerium, praseodymium, or neodymium is used under the same conditions, the glass reacts with the acidic component, rendering it unusable after storage.

[0033] In contrast, the dental composition of this embodiment can improve storage stability in an acidic environment by using an acidic component and at least one lanthanoid fluoride powder selected from the group consisting of fluoride powders of lanthanoids having an atomic number of 66 or less. Furthermore, the dental composition of this embodiment can maintain its storage stability in an acidic environment, thereby maintaining the function of the lanthanoid fluoride powder as an X-ray contrast agent and high X-ray contrast properties.

[0034] The dental composition of this embodiment may further contain a filler other than the lanthanide fluoride powder. Such a filler is not particularly limited, but is preferably an aluminosilicate glass, more preferably a fluoroaluminosilicate glass. Here, the fluoroaluminosilicate glass is an oxyfluoride glass of aluminum and silicon, and is glass that can be imparted with fluorine sustained-release properties.

[0035] The composition of the fluoroaluminosilicate glass is not particularly limited, and for example, in terms of ion mass ratio, silicon is 10% by mass to 33% by mass, aluminum is 4% by mass to 30% by mass, alkaline earth metal is 5% by mass to 36% by mass, alkali metal is 0% by mass to 10% by mass, phosphorus is 0.2% by mass to 16% by mass, fluorine is 2% by mass to 40% by mass, and the balance is oxygen.

[0036] In addition, the alkaline earth metals in the fluoroaluminosilicate glass are preferably calcium, magnesium, strontium, or barium. Furthermore, the alkali metals are preferably sodium, lithium, or potassium, with sodium being more preferred. Furthermore, if necessary, a portion of the aluminum may be replaced with titanium, yttrium, zirconium, hafnium, tantalum, lanthanum, or the like.

[0037] Such fluoroaluminosilicate glass can be produced by, for example, mixing silica, alumina, fluorite, cryolite, aluminum fluoride or other metal compounds, sintering the mixture at 1100 to 1300°C, and then pulverizing it, or by a sol-gel method, etc. The inorganic filler can also be surface-treated using a surface treatment agent such as a silane coupling agent by a known method before use.

[0038] Suitable silane coupling agents include methyltrimethoxysilane, methyltriethoxysilane, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, vinyltrichlorosilane, vinylethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, and hexamethyldisilazane.

[0039] Furthermore, the fluoroaluminosilicate glass may be coated with a polymer compound or the like for the purpose of improving compatibility with other components.

[0040] The content of the aluminosilicate glass is not particularly limited, and the content of the fluoroaluminosilicate glass in the dental composition is, for example, 1% by mass to 40% by mass, preferably 5% by mass to 35% by mass, and more preferably 10% by mass to 30% by mass.

[0041] When the content of fluoroaluminosilicate glass in the dental composition is 1% by mass or more, the dental composition can be endowed with fluoride sustained-release properties. When the content of fluoroaluminosilicate glass in the dental composition is 40% by mass or less, the amounts of other components in the dental composition can be ensured, and the physical properties of the dental composition can be improved.

[0042] The dental composition of the present embodiment may contain other components as long as the purpose of the present invention is not impaired. Examples of other components contained in the dental composition include polymerizable monomers, polymerization initiators, polymerization inhibitors, Viscosity modifier , solvents.

[0043] The polymerizable monomer is not particularly limited, but for example, the polymerizable monomer is preferably a radical polymerizable monomer, and more preferably a (meth)acrylate.

[0044] In this specification, (meth)acrylate refers to an acrylate and / or methacrylate, having one or more (meth)acryloyloxy groups. In addition, the (meth)acryloyloxy group means a methacryloyloxy group and / or an acryloyloxy group.

[0045] Examples of the radical polymerizable monomer include α-cyanoacrylic acid esters, (meth)acrylic acid esters, α-haloacrylic acid esters, crotonates, cinnamates, sorbates, maleates, itaconates, (meth)acrylamides, (meth)acrylamide derivatives, vinyl esters, vinyl ethers, mono-N-vinyl derivatives, styrene derivatives, etc., and two or more of these may be used in combination. Among these, (meth)acrylic acid esters and (meth)acrylamide derivatives are preferred, and (meth)acrylic acid esters are more preferred.

[0046] Examples of the monofunctional radically polymerizable monomer include methyl (meth)acrylate, isobutyl (meth)acrylate, benzyl (meth)acrylate, lauryl (meth)acrylate, 2,3-dibromopropyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, propylene glycol mono(meth)acrylate, glycerin mono(meth)acrylate, erythritol mono(meth)acrylate, N-methylol (meth)acrylamide, N-hydroxyethyl (meth)acrylamide, N-dihydroxyethyl (meth)acrylamide, (meth)acryloyloxydodecylpyridinium bromide, (meth)acryloyloxydodecylpyridinium chloride, (meth)acryloyloxyhexadecylpyridinium chloride, and (meth)acryloyloxydecylammonium chloride.

[0047] Examples of the bifunctional radical polymerizable monomer include ethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 2,2-bis[4-[3-(meth)acryloyloxy-2-hydroxypropoxy]phenyl]propanol ... [2,2,4-trimethylhexamethylenebis(2-carbamoyloxyethyl)]di(meth)acrylate, 2,2-bis[4-(2-(meth)acryloyloxyethoxy)phenyl]propane, 2,2-bis[4-(meth)acryloyloxypolyethoxyphenyl]propane, 1,2-bis[3-(meth)acryloyloxy-2-hydroxypropoxy]ethane, pentaerythritol di(meth)acrylate, and [2,2,4-trimethylhexamethylenebis(2-carbamoyloxyethyl)]di(meth)acrylate.

[0048] Examples of the trifunctional or higher radical polymerizable monomer include trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, N,N ' -(2,2,4-trimethylhexamethylene)bis[2-(aminocarboxy)propane-1,3-diol]tetramethacrylate, 1,7-diacryloyloxy-2,2,6,6-tetraacryloyloxymethyl-4-oxyheptane, and the like.

[0049] These polymerizable monomers body One type may be used alone, or two or more types may be used in combination.

[0050] The content of the polymerizable monomer in the dental composition is not particularly limited, and can be, for example, 0.1% by mass or more and 50% by mass or less, preferably 0.5% by mass or more and 35% by mass or less, and more preferably 1% by mass or more and 25% by mass or less. When the content of the polymerizable monomer in the dental composition is 0.1% by mass or more, the adhesiveness of the dental composition to tooth structure is further improved, and when it is 50% by mass or less, the blending amounts of other components in the dental composition can be secured, and the physical properties of the dental composition are improved.

[0051] Examples of the polymerization initiator include a chemical polymerization initiator and a photopolymerization initiator.

[0052] The chemical polymerization initiator is not particularly limited, and for example, a thiourea derivative, a vanadium compound, a tertiary amine, or an organic peroxide can be used.

[0053] Thiourea derivatives function as reducing agents among chemical polymerization initiators.

[0054] The thiourea derivative is not particularly limited, and examples thereof include ethylene thiourea, N-methyl thiourea, N-ethyl thiourea, N-propyl thiourea, N-butyl thiourea, N-lauryl thiourea, N-phenyl thiourea, N-cyclohexyl thiourea, N,N-dimethyl thiourea, N,N-diethyl thiourea, N,N-dipropyl thiourea, N,N-dibutyl thiourea, N,N-dilauryl thiourea, N,N-diphenyl thiourea, N,N-dicyclohexyl thiourea, trimethyl thiourea, tetramethyl thiourea, N-acetyl thiourea, N-benzoyl thiourea, 1-allyl-3-(2-hydroxyethyl)-2-thiourea, 1-(2-tetrahydrofurfuryl)-2-thiourea, N-tert-butyl-N′-isopropyl thiourea, and 2-pyridyl thiourea.

[0055] These thiourea derivatives teeth One type may be used alone, or two or more types may be used in combination. Among these, N-benzoylthiourea is preferred in terms of improving the hardening properties of the dental composition.

[0056] The content of the thiourea derivative in the dental composition is not particularly limited, but is preferably 0.1% by mass to 10% by mass, more preferably 0.1% by mass to 5% by mass, and even more preferably 0.1% by mass to 2% by mass. When the content of the thiourea derivative in the dental composition is 0.1% by mass or more, the hardening property of the dental composition is further improved, and when it is 10% by mass or less, the solubility of the thiourea derivative in (meth)acrylate in the dental composition is improved.

[0057] The vanadium compound functions as a reducing agent among chemical polymerization initiators.

[0058] The vanadium compound is not particularly limited and examples thereof include oxovanadium oxalate, vanadyl acetylacetonate, vanadyl acetylacetonate, vanadyl stearate, vanadium naphthenate, vanadium benzoylacetonate, etc., and two or more of these may be used in combination. Among these, vanadyl acetylacetonate is preferred in terms of the hardening properties of the dental composition.

[0059] The content of the vanadium compound in the dental composition is not particularly limited, but is preferably 0.001% by mass or more and 10% by mass or less, more preferably 0.0015% by mass or more and 5% by mass or less, and even more preferably 0.002% by mass or more and 3% by mass or less. When the content of the vanadium compound in the dental composition is 0.001% by mass or more, the hardenability of the dental composition is further improved, and when it is 10% by mass or less, the storage stability of the dental composition is further improved.

[0060] Tertiary amines function as reducing agents among chemical polymerization initiators.

[0061] The tertiary amine is not particularly limited, and examples thereof include tertiary aliphatic amines and tertiary aromatic amines.

[0062] Examples of tertiary aliphatic amines include N,N-dimethylaminoethyl methacrylate and triethanolamine.

[0063] Examples of tertiary aromatic amines include alkyl p-dialkylaminobenzoates, 7-dimethylamino-4-methylcoumarin, N,N-dimethylaniline, N,N-dibenzylaniline, N,N-dimethyl-p-toluidine, N,N-diethyl-p-toluidine, N,N-bis(2-hydroxyethyl)-p-toluidine, N,N,2,4,6-pentamethylaniline, N,N,2,4-tetramethylaniline, and N,N-diethyl-2,4,6-trimethylaniline.

[0064] Of these, the tertiary amine is preferably a tertiary aromatic amine, more preferably an alkyl p-dialkylaminobenzoate.

[0065] Examples of alkyl p-dialkylaminobenzoates include methyl p-dimethylaminobenzoate, ethyl p-dimethylaminobenzoate, propyl p-dimethylaminobenzoate, amyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, ethyl p-diethylaminobenzoate, and propyl p-diethylaminobenzoate.

[0066] These tertiary amines may be used alone or in combination of two or more.

[0067] Among chemical polymerization initiators, organic peroxides function as oxidizing agents.

[0068] Examples of organic peroxides include benzoyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, t-amyl hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, 2,5-dimethyl-2,5-di(hydroperoxy)hexane, p-diisopropylbenzene monohydroperoxide, p-methane hydroperoxide, and pinane hydroperoxide.

[0069] These organic peroxides may be used alone or in combination of two or more. Among these, cumene hydroperoxide is preferred in terms of the hardening properties of the dental composition.

[0070] The content of the organic peroxide in the dental composition is not particularly limited, but is preferably 0.01% by mass or more and 10% by mass or less, more preferably 0.05% by mass or more and 5% by mass or less, and even more preferably 0.1% by mass or more and 3% by mass or less. When the content of the organic peroxide in the dental composition is 0.01% by mass or more, the hardening property of the dental composition is further improved, and when it is 10% by mass or less, the working time of the dental composition is extended.

[0071] The photopolymerization initiator is not particularly limited, and examples thereof include camphorquinone, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, benzil ketal, diacetyl ketal, benzil dimethyl ketal, benzil diethyl ketal, benzil bis(2-methoxyethyl) ketal, 4,4'-dimethyl(benzyl dimethyl ketal), anthraquinone, 1-chloroanthraquinone, 2-chloroanthraquinone, 1,2-benzanthraquinone, 1-hydroxyanthraquinone, 1-methylanthraquinone, 2-ethylanthraquinone, 1-bromoanthraquinone, 1-methylanthraquinone, 2-ethylanthraquinone, and 1-bromoanthraquinone. Examples of suitable thioxanthone include trichloroquinone, thioxanthone, 2-isopropylthioxanthone, 2-nitrothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, 2-chloro-7-trifluoromethylthioxanthone, thioxanthone-10,10-dioxide, thioxanthone-10-oxide, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzophenone, bis(4-dimethylaminophenyl)ketone, and 4,4'-bis(diethylamino)benzophenone.

[0072] These photopolymerization initiators may be used alone or in combination of two or more. Among these, camphorquinone and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide are preferred in terms of improving the curability of the dental composition.

[0073] The content of the photopolymerization initiator in the dental composition is not particularly limited, but is preferably 0.001% by mass or more and 10% by mass or less, more preferably 0.005% by mass or more and 5% by mass or less, and even more preferably 0.01% by mass or more and 33% by mass or less. When the content of the photopolymerization initiator in the dental composition is 0.001% by mass or more, the hardening property of the dental composition is further improved, and when it is 10% by mass or less, the storage stability of the dental composition is further improved.

[0074] Examples of the polymerization inhibitor include dibutylhydroxytoluene (2,6-di-tert-butyl-p-cresol) and 6-tert-butyl-2,4-xylenol.

[0075] These polymerization inhibitors may be used alone or in combination of two or more. Among these, dibutylhydroxytoluene is preferred in terms of improving the hardening properties of the dental composition.

[0076] The content of the polymerization inhibitor in the dental composition is not particularly limited, but when it is contained, it is sufficient that it is 0.001% by mass or more and 5% by mass or less, preferably 0.005% by mass or more and 1% by mass or less, and more preferably 0.01% by mass or more and 0.1% by mass or less. When the content of the polymerization inhibitor in the dental composition is 0.001% by mass or more and 5% by mass or less, the storage stability of the dental composition is improved.

[0077] The viscosity modifier is not particularly limited, and for example, a fine filler having a particle size of 0.07 μm or less, preferably 0.5 μm to 0.05 μm, is used. Examples of such fine fillers include silica fine powder, alumina fine powder, and carboxymethylcellulose sodium salt (CMC-Na). These viscosity modifiers may be used alone or in combination of two or more.

[0078] Viscosity modifier Contains The amount is not particularly limited, and is, for example, 0.01% by mass or more and 25% by mass or less, preferably 0.1% by mass or more and 20% by mass or less, and more preferably 1% by mass or more and 15% by mass or less in the dental composition. 25 When the content is 100% by mass or less, the mechanical strength of the cured product of the dental composition is improved and a decrease in surface smoothness is suppressed.

[0079] The solvent is not particularly limited, but examples thereof include water and organic solvents.

[0080] Examples of the organic solvent include ethanol, acetone, propanol, and glycerin.

[0081] These solvents may be used alone or in combination of two or more. Among these, a solvent obtained by mixing glycerin with water is preferred from the viewpoint of not reacting with the oxide powder and improving the wettability of the dental composition to tooth tissue.

[0082] The solvent content is not particularly limited, but is, for example, 5% by mass or more and 50% by mass or less, preferably 10% by mass or more and 40% by mass or less, and more preferably 20% by mass or more and 35% by mass or less in the dental composition.

[0083] The dental composition of this embodiment may be configured as a dental composition containing a first agent and a second agent.

[0084] The first agent contains an agent containing an acidic component and the above-mentioned lanthanoid fluoride powder.

[0085] The acidic component in the first agent is not particularly limited, but for example, the above-mentioned acidic component is used. Specifically, the acidic component in the first agent is the above-mentioned polycarboxylic acid, and preferably the above-mentioned polyacrylic acid.

[0086] The content of the acidic component in the first agent is not particularly limited, but is, for example, 1% by mass to 50% by mass, preferably 7% by mass to 40% by mass, and more preferably 10% by mass to 35% by mass. When the content of the acidic component in the first agent is 1% by mass to 50% by mass, the blending amounts of other components can be ensured, and the physical properties of the dental composition are improved.

[0087] The lanthanoid fluoride powder in the first agent is not particularly limited, but the above-mentioned lanthanoid fluoride powder is used. Specifically, the lanthanoid fluoride powder in the first agent is at least one lanthanoid fluoride powder selected from the group consisting of lanthanoid fluoride powders having an atomic number of 66 or less, and is preferably ... above-mentioned lanthanum, cerium, praseodymium, and neodymium.

[0088] The content of the lanthanoid fluoride powder in the first agent is not particularly limited, and may be, for example, 1% by mass or more and 90% by mass or less, preferably 5% by mass or more and 75% by mass or less, and more preferably 10% by mass or more and 45% by mass or less.

[0089] By setting the content of the lanthanoid fluoride powder in the first agent to 1% by mass or more, the effect of the lanthanoid fluoride powder as an X-ray contrast agent is enhanced, and by setting the content of the lanthanoid fluoride powder in the first agent to 90% by mass or less, the amounts of other components in the first agent can be ensured, improving the physical properties of the dental composition.

[0090] The first agent may also contain the above-mentioned polymerization initiator, viscosity modifier, and solvent as other components.

[0091] As such a first agent, for example, the agent constituting the dental composition described above can be used.

[0092] The first agent can be made into a paste by containing a polycarboxylic acid, which makes the first agent easier to handle as an agent constituting the dental composition.

[0093] The second agent contains an aluminosilicate glass and a (meth)acrylate.

[0094] The aluminosilicate glass in the second agent is not particularly limited, but for example, the above-mentioned aluminosilicate glass is used. Specifically, the aluminosilicate glass in the second agent is the above-mentioned aluminosilicate glass, and is preferably fluoroaluminosilicate glass.

[0095] The content of the aluminosilicate glass in the second agent is not particularly limited. The content of the fluoroaluminosilicate glass in the second agent is, for example, 10% by mass or more and 85% by mass or less, preferably 15% by mass or more and 80% by mass or less, and more preferably 20% by mass or more and 75% by mass or less.

[0096] When the content of fluoroaluminosilicate glass in the second part is 10% by mass or more, the dental composition containing the second part can be imparted with sufficient sustained fluoride release properties. When the content of fluoroaluminosilicate glass in the second part is 85% by mass or less, the amounts of other components in the dental composition can be ensured, improving the physical properties of the dental composition.

[0097] The (meth)acrylate in the second agent is not particularly limited, but for example, a polymerizable monomer contained in the other components described above is used. Specifically, the (meth)acrylate in the second agent is a polymerizable monomer that is the other component described above, and is preferably the (meth)acrylate described above.

[0098] The content of (meth)acrylate in the second agent is not particularly limited, and can be, for example, 0.1% by mass to 50% by mass, preferably 0.5% by mass to 40% by mass, and more preferably 1% by mass to 30% by mass. When the content of the polymerizable monomer in the second agent is 0.1% by mass or more, the adhesiveness of the dental composition containing the second agent to tooth structure is further improved, and when it is 50% by mass or less, the blending amounts of other components in the dental composition can be secured, and the physical properties of the dental composition are improved.

[0099] The second agent also contains the above-mentioned polymer as another component. ProhibitedThe composition may contain a viscosity modifier, a solvent, or the like.

[0100] The second agent can be made into a paste by containing a (meth)acrylate, which makes the second agent easier to handle as the other agents that make up the dental composition.

[0101] The mass ratio of the first part to the second part of the dental composition of this embodiment is usually 10:1 to 1:10, preferably 1:5 to 5:1, and more preferably 1:3 to 3:1. When the mass ratio of the first part to the second part is 10:1 to 1:10, the ratio of the reactive components in the composition becomes appropriate, which contributes to improving the physical properties.

[0102] In the dental composition of this embodiment, the first and second parts can be kneaded together before use.

[0103] In this embodiment, as described above, even when the dental composition contains a first agent and a second agent, the storage stability in an acidic environment can be improved by using in the first agent at least one lanthanoid fluoride powder selected from the group consisting of an acidic component and a lanthanoid fluoride powder having an atomic number of 66 or less.

[0104] The dental composition of the present embodiment may be used for, but is not limited to, various dental materials. Examples of dental materials include dental cement, dental adhesive, dental temporary sealing material, dental primer, dental coating material, dental composite resin, dental hard resin, dental cutting resin material, dental temporary restorative material, dental filler, and dentifrice. Among these, the dental composition is preferably used for dental cement. [Example]

[0105] The present invention will be further described below using examples. In the following, numerical values ​​without units or "%" are by mass (% by mass) unless otherwise specified.

[0106] <Preparation of the first agent> [Examples 1 to 6, Comparative Examples 1 and 2] An X-ray contrast medium, an acidic component, a polymerization initiator, a viscosity modifier, and a solvent (water) were mixed in the composition (mass %) shown in Table 1 to obtain a paste of the first agent (hereinafter referred to as the first paste).

[0107] <Preparation of second agent> [Formulation examples 1 and 2] Fluoroaluminosilicate glass, polymerizable monomer, polymerization inhibitor, viscosity modifier, and solvent (water) were mixed according to the composition (mass %) shown in Table 2 to obtain a paste of the second part (hereinafter referred to as second paste) 2.

[0108] [Table 1]

[0109] [Table 2]

[0110] The storage stability of the first paste was confirmed as follows.

[0111] <Storage stability> Place approximately 2 g of the first paste on a mixing paper and use a plastic spatula to widely mix and loosen the paste for approximately 15 seconds. Measure the loosened paste into a glass tube (10 mm inner diameter, marked at the 0.5 mL position) for measuring consistency and gently extrude it onto a plastic sheet.

[0112] Place a plastic sheet, a glass plate (weighing approximately 20 g), and a weight (weighing approximately 100 g) on ​​top of this so that the total weight is 120 ± 0.5 g. After 2 minutes have passed since the load was applied, remove the weight and glass plate and take the average of the long and short diameters of the spread sample to determine the initial consistency.

[0113] The prepared first paste was evaluated according to the following criteria. If the evaluation is A, it is judged that the preservability is good; if the evaluation is B, it is judged that the preservability is poor. The results of the storage stability are shown in Table 1.

[0114] 〔Evaluation Criteria〕 A: The consistency immediately after preparation is 25 mm or more, and the consistency after standing at 23 °C for 2 weeks from the preparation is re-measured and is 80% or more of the initial value. B: The consistency immediately after preparation is less than 25 mm, or when the consistency after standing at 23 °C for 2 weeks from the preparation is re-measured, it is less than 80% of the initial value.

[0115] The first paste and the second paste were mixed and kneaded at a mass ratio of 1:1 to obtain a cured body. For the obtained cured body, the X-ray contrastability was confirmed as follows. In addition, the X-ray contrastability of Examples 1 to 5 and Comparative Examples 1 and 2 shows the X-ray contrastability of the mixture of Examples 1 to 5 as the first paste and Formulation Example 1 as the second paste. Also, the X-ray contrastability of Example 6 is the mixture of Example 6 as the first paste and Formulation Example 2 as the second paste of shows X-ray contrastability.

[0116] <X-ray Contrastability> Using a digital X-ray unit or a single-phase dental X-ray unit as a diagnostic integrated X-ray generator defined in JIS Z 4711 or operable at a tube voltage of 65 ± 5 kV and having the ability to completely transmit an aluminum plate with a thickness of 1.5 mm.

[0117] Calibrate according to the size of the film for X-ray sensor occlusal imaging because a digital X-ray unit is used (for example, use one calibrated for use with a charge-coupled device (CCD), a photostimulable phosphor plate (image plate), and a single-phase dental X-ray unit with appropriate software). Furthermore, as software capable of tone analysis, use software suitable for tone analysis.

[0118] The aluminum step wedge used is made of aluminum with a mass fraction of 98% or more purity (mass fraction of copper less than 0.1%, mass fraction of iron less than 1.0%), with overall dimensions of 50 mm length x 20 mm width, and a thickness ranging from 0.5 to 5.0 mm, with equally spaced steps every 0.50 ± 0.01 mm. All stepped surfaces of the wedge are parallel to the X-ray film and perpendicular to the X-ray.

[0119] Use a mold capable of producing test pieces 15±1 mm in diameter and 1.0±0.1 mm or 1.00±0.01 mm in thickness. Use a transparent film 50±30 μm thick (e.g., polyester, non-sticky to the sample, and non-grainy). Use glass slides or plates made of glass, stainless steel, or other smooth, hard materials.

[0120] Use a thermo-hygrostat capable of maintaining a temperature of 37±1°C and a humidity of 50% or more. Use a micrometer or equivalent specified in JIS B 7502 with a reading of 0.01 mm or more. Use a clip or equivalent clamp (e.g., one that can hold the mold while the cement hardens).

[0121] Use abrasive paper (P2000 or P2500) that conforms to JIS R 6252 or JIS R 6253. Use a lead sheet with a thickness of 2.0 mm or more. In addition, use a light irradiator.

[0122] Place a film on a glass slide or plate and place a mold on top of that. Extrude the cement mixture and fill the mold with a little excess. Place a film on top of the cement, cover it with a glass slide or plate, and extrude the excess cement. Pressurize this with a clamp. Three minutes after the start of mixing, place the integrated product in a thermo-hygrostat maintained at 37±1°C for 30 minutes.

[0123] Remove the test specimen from the mold and measure the thickness near the center of the disk using a micrometer. Only test specimens with a thickness of 1.0 ± 0.1 mm should be used. If the test specimen is too thick, it may be polished with abrasive paper until it reaches the specified thickness. Place the test specimen in distilled or purified water at 23 ± 1°C and test within 7 days. To prevent the test specimen from drying out, test the specimen within 30 minutes of removing it from the water.

[0124] As a measurement procedure, before taking an image, the automatic density correction function is disabled using the digital X-ray equipment software. The thickness (TS) of the test piece is measured with a micrometer to an accuracy of 0.01 m. The X-ray sensor is placed on the lead sheet. The test piece and step wedge are placed in the center of the sensor. Without using the automatic density correction function, the distance between the cathode and X-ray sensor is set to 400 mm, and the test piece and step wedge are irradiated with X-rays.

[0125] The exposure is repeated for different exposure times until a clear image is obtained. The digital image file is transferred to software capable of gray value analysis. Using the measurement tool in the software capable of gray value analysis, a rectangular region is defined in the specimen image and the average gray value within that region is measured. This procedure is then repeated for each step image of the step wedge.

[0126] The gray value for each step of the step wedge is plotted against the thickness of each step to determine the relationship between aluminum thickness and gray value. The aluminum thickness (Ta) is determined for the gray value of a test piece with a thickness of TS. The X-ray contrast (aluminum equivalent) value for a unit thickness (1.0 mm) of the test piece is determined by dividing by Ta and TS. The X-ray contrast results are shown in Table 1.

[0127] As can be seen from Table 1, the dental compositions (first and second agents) (Examples 1 to 5, Example 6) containing an agent containing an acidic component and at least one lanthanoid fluoride powder selected from the group consisting of lanthanoid fluoride powders having an atomic number of 66 or less had good storage stability and X-ray contrast properties.

[0128] In contrast, when at least one lanthanoid fluoride powder selected from the group consisting of lanthanoid fluoride powders with atomic numbers of 66 or less was not contained, and when ytterbium fluoride was contained instead of at least one lanthanoid fluoride powder selected from the group consisting of lanthanoid fluoride powders with atomic numbers of 66 or less, the storage stability was poor (Comparative Examples 1 and 2).

[0129] Although the embodiments of the present invention have been described above, the present invention is not limited to the specific embodiments, and various modifications and changes are possible within the scope of the invention described in the claims.

Claims

1. Acidic components, and At least one lanthanide fluoride powder selected from the group consisting of lanthanide fluoride powders having an atomic number of 66 or less, the acidic component comprises a polycarboxylic acid; Dental compositions.

2. The lanthanoid fluoride powder is lanthanum fluoride powder, cerium fluoride powder, praseodymium fluoride powder, or neodymium fluoride powder. The dental composition of claim 1 .

3. The dental composition is in a paste form. The dental composition according to claim 1 or 2.

4. Further, the glass contains aluminosilicate glass. The dental composition according to any one of claims 1 to 3.

5. A dental composition comprising a first agent and a second agent, The first agent is Acidic components, and At least one lanthanide fluoride powder selected from the group consisting of lanthanide fluoride powders having an atomic number of 66 or less, the acidic component comprises a polycarboxylic acid; Dental compositions.

6. The lanthanoid fluoride powder is lanthanum fluoride powder, cerium fluoride powder, praseodymium fluoride powder, or neodymium fluoride powder, The second agent is Contains aluminosilicate glass and (meth)acrylate. The dental composition of claim 5 .

7. A dental composition containing a first agent and a second agent, The first agent is Acidic components, and At least one lanthanide fluoride powder selected from the group consisting of lanthanide fluoride powders having an atomic number of 66 or less, the lanthanoid fluoride powder is lanthanum fluoride powder, cerium fluoride powder, praseodymium fluoride powder, or neodymium fluoride powder; The first agent further contains polyacrylic acid, The second agent is Contains aluminosilicate glass and (meth)acrylate. Dental compositions.

Images