Dental glass composition

Abstract

To provide a glass composition that is superior in both X-ray contrast and aesthetic properties.SOLUTION: A glass composition includes: gadolinium (Gd) and / or cesium (Cs); and silicon (Si). The glass composition has a total content of gadolinium oxide and cesium oxide of 1 mass% or higher and a content of silicon oxide of 30 mass% or higher, in terms of oxide.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a glass composition.

Background Art

[0002] As an X-ray contrast glass, barium glass is known (see, for example, Patent Document 1). X-ray contrast means X-ray impermeability. The higher the X-ray impermeability, that is, the lower the X-ray transmittance, the better the X-ray contrast.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] One aspect of the present invention provides a glass composition excellent in X-ray contrast and aesthetic properties.

Means for Solving the Problems

[0005] According to one aspect of the present invention Dental the glass composition contains at least one of gadolinium (Gd) and cesium (Cs) and silicon (Si). Dental In terms of oxide conversion, the total content of gadolinium oxide and cesium oxide in the glass composition is 1% by mass or more, The gadolinium oxide content is 12% to 30% by mass, and the content of silicon oxide is 30% by mass or more.

Effects of the Invention

[0006] According to one aspect of the present invention, a glass composition excellent in X-ray contrast and aesthetic properties can be provided.

Modes for Carrying Out the Invention

[0007] The following describes embodiments for carrying out the present invention. In this specification, the "~" indicating a numerical range means that the numerical values ​​before and after it are included as the lower and upper limits, respectively.

[0008] The glass composition of this embodiment contains at least one of gadolinium (Gd) and cesium (Cs), and silicon (Si). The glass composition may contain only one of gadolinium or cesium, but it is preferable that it contains both.

[0009] Gadolinium is a rare earth element in which its 4f orbital, which can hold up to 14 electrons, is occupied by only 7 electrons, half the maximum number of electrons that can be occupied, and all of the occupying electrons are unpaired. Because the 4f orbital is occupied by 7 unpaired electrons in this way, gadolinium has the highest magnetic moment among 4f elements.

[0010] Cesium (atomic number 55) has the second largest atomic number after barium (atomic number 56), and therefore exhibits high X-ray contrast properties. Furthermore, since cesium is an alkali metal element, mixing it with other alkali metal elements (e.g., sodium) can produce a mixed alkali ion effect, improving water resistance and chemical resistance.

[0011] By including at least one of gadolinium and cesium, the glass composition can reduce the barium (Ba) content while suppressing a decrease in X-ray contrast properties, and it is even possible to substantially eliminate barium. X-ray contrast properties refer to X-ray opacity. The higher the X-ray opacity, that is, the lower the X-ray transmittance, the better the X-ray contrast properties.

[0012] The radiopaqueness of glass compositions is measured according to the radiopaqueness test method for dental materials in accordance with ISO 13116:2014. Specifically, first, the optical density or Gray value of a test specimen (plate-shaped glass composition) with a thickness Ts (unit: mm) is measured. Next, the thickness Ta (unit: mm) of an aluminum plate that exhibits the same optical density or Gray value as the test specimen of thickness Ts is determined. The ratio of Ta to Ts (unit: %) is then used as the value of radiopaqueness.

[0013] The higher the ratio of Ta to Ts, the better the X-ray contrast (X-ray opacity). The ratio of Ta to Ts is preferably 200% or more, more preferably 400% or more, even more preferably 600% or more, and particularly preferably 800% or more. The ratio of Ta to Ts is preferably 1200% or less.

[0014] As described above, the glass composition contains at least one of gadolinium and cesium, which allows for a reduction in barium content while suppressing a decrease in X-ray contrast. This allows the refractive index of the glass composition to be adjusted to 1.45 or higher and less than 1.56. In this specification, refractive index refers to the refractive index in the D line (light ray with a wavelength of 589 nm).

[0015] If the refractive index of the glass composition is 1.45 or higher and less than 1.56, the refractive index difference between the polymerizable monomer (described later) and the glass composition can be reduced, improving the transparency of the dental polymerizable composition (described later) and enhancing its aesthetics. The refractive index of the polymerizable monomer is approximately 1.50 or higher and 1.52 or lower.

[0016] The refractive index of the glass composition is preferably 1.45 or more and less than 1.56, as described above. More preferably, the refractive index of the glass composition is 1.50 or more, and even more preferably 1.52 or more. Furthermore, the refractive index of the glass composition is more preferably 1.54 or less.

[0017] The glass composition preferably contains 1% by mass or more of gadolinium oxide (Gd2O3) and cesium oxide (Cs2O) in terms of oxides. If the total content of gadolinium oxide and cesium oxide is 1% by mass or more, a glass composition with excellent X-ray contrast properties and aesthetics can be obtained.

[0018] The total content of gadolinium oxide and cesium oxide in the glass composition is more preferably 5% by mass or more, and even more preferably 9% by mass or more. Also, the total content of gadolinium oxide and cesium oxide in the glass composition is preferably 50 mass% or less, and more preferably 40 mass% or less.

[0019] In the glass composition, the content of gadolinium oxide in terms of oxide is preferably 0% by mass to 40% by mass, more preferably 12% by mass to 30% by mass, and even more preferably 15% by mass to 25% by mass. If the content of gadolinium oxide is 40% by mass or less, it is possible to suppress the coloring of the dental polymerizable composition after curing.

[0020] In the glass composition, the content of cesium oxide in terms of oxide is preferably 0% by mass to 20% by mass, more preferably 5% by mass to 17% by mass, and even more preferably 8% by mass to 15% by mass.

[0021] The glass composition may not substantially contain barium, but may contain barium. By containing barium in the glass composition, the contents of gadolinium and cesium can be reduced. In the glass composition, the content of barium oxide (BaO) in terms of oxide is preferably 0% by mass or more and less than 30% by mass. If the content of barium oxide is less than 30% by mass, the refractive index of the glass composition can be adjusted to less than 1.56. The content of barium oxide is more preferably 8% by mass to 25% by mass, and even more preferably 13% by mass to 22% by mass.

[0022] In the glass composition, the content of silicon oxide (SiO2) in terms of oxide is preferably 30% by mass to 80% by mass, more preferably 35% by mass to 70% by mass, and even more preferably 45% by mass to 65% by mass. If the content of silicon oxide is 30% by mass or more, it is easy to adjust the viscosity of the dental polymerizable composition and the mechanical strength can be improved. Also, if the content of silicon oxide is 80% by mass or less, a decrease in X-ray contrast can be suppressed.

[0023] The glass composition may contain elements other than gadolinium, cesium, barium, and silicon. Examples of other elements include, for example, aluminum (Al), boron (B), sodium (Na), and fluorine (F).

[0024] Based on oxides, the glass composition preferably contains 0% to 20% by mass, more preferably 3% to 15% by mass, and still more preferably 5% to 10% by mass of aluminum oxide (Al2O3). If the content of aluminum oxide is 3% by mass or more, the chemical durability and mechanical strength can be improved. Also, if the content of aluminum oxide is 20% by mass or less, devitrification and reduction of acid resistance can be suppressed.

[0025] Based on oxides, the glass composition preferably contains 0% to 14% by mass, more preferably 3% to 12% by mass, and still more preferably 5% to 8% by mass of boron oxide (B2O3). If the content of boron oxide is 3% by mass or more, crystallization of the glass can be suppressed. Also, if the content of boron oxide is 14% by mass or less, reduction of chemical durability and non-uniformity of the refractive index can be suppressed.

[0026] Based on oxides, the glass composition preferably contains 0% to 20% by mass, more preferably 3% to 15% by mass, and still more preferably 5% to 10% by mass of sodium oxide (Na2O). If the content of sodium oxide is 20% by mass or less, reduction of chemical durability and reduction of water resistance can be suppressed.

[0027] The glass composition preferably contains 0% to 5% by mass, more preferably 0% to 3% by mass, and still more preferably 0% to 1% by mass of fluorine (F). If the content of fluorine is 5% by mass or less, it is easy to adjust the viscosity of the dental polymerizable composition.

[0028] The glass composition is in powder or plate form. A powdered glass composition is glass powder, and a plate-like glass composition is a glass plate. When the glass composition is used as part of a dental polymerizable composition, it is preferable that the glass composition be in powder form. The method for grinding the glass plate into glass powder can be a general method, and may be dry or wet. Planetary mills, vibratory mills, ball mills, or bead mills can be used.

[0029] When the glass composition is in powder form, its average particle size is preferably 80 nm to 1000 nm, more preferably 100 nm to 900 nm, and even more preferably 150 nm to 800 nm. In this specification, the average particle size refers to the volume-based median diameter D50, measured by dynamic light scattering.

[0030] The glass composition can also be used as radiation shielding glass. In this case, the glass composition may be used in sheet form or in powder form mixed with acrylic. In either case, by using the glass composition of this embodiment instead of lead glass, the amount of lead used can be reduced.

[0031] Next, the details of the dental polymerizable composition will be described. The dental polymerizable composition contains the glass composition described above. The content of the glass composition in the dental polymerizable composition is preferably 40% by mass or more and 90% by mass or less, more preferably 50% by mass or more and 80% by mass or less, and even more preferably 60% by mass or more and 70% by mass or less.

[0032] When the glass composition content in a dental polymerizable composition is 40% by mass or more, the dental polymerizable composition can be given high radiopaqueness and improved mechanical strength. Furthermore, when the glass composition content in a dental polymerizable composition is 90% by mass or less, the viscosity of the dental polymerizable composition is low, improving the operability of the dental polymerizable composition.

[0033] The dental polymerizable composition contains a (meth)acrylate compound in addition to the glass composition described above. In this specification, a polymerizable composition refers to a composition that has the function of polymerization. A (meth)acrylate compound refers to a monomer, oligomer, or prepolymer having one or more (meth)acryloyloxy groups of (meth)acrylate. In this specification, (meth)acrylate refers to either or both acrylate and methacrylate.

[0034] The (meth)acrylate is not particularly limited and may be, for example, a (meth)acrylate having an acid group, a (meth)acrylate without an acid group, or both. The (meth)acrylate having an acid group may have multiple acid groups. Alternatively, acid chlorides, alkali metal salts, and amine salts of (meth)acrylate having an acid group may be used.

[0035] Examples of (meth)acrylates having an acidic group include (meth)acrylates having a phosphoric acid group, (meth)acrylates having a pyrophosphate group, (meth)acrylates having a thiophosphate group, (meth)acrylates having a carboxyl group, (meth)acrylates having a sulfonic acid group, and (meth)acrylates having a phosphonic acid group.

[0036] Examples of (meth)acrylates having a phosphate group include 2-(meth)acryloyloxyethyl dihydrogen phosphate, bis[2-(meth)acryloyloxyethyl]hydrogen phosphate, 2-(meth)acryloyloxyethyl phenylhydrogen phosphate, 6-(meth)acryloyloxyhexyl dihydrogen phosphate, 6-(meth)acryloyloxyhexyl phenylhydrogen phosphate, 10-(meth)acryloyloxydecyl dihydrogen phosphate, 1,3-di(meth)acryloylpropane-2-dihydrogen phosphate, 1,3-di(meth)acryloylpropane-2-phenylhydrogen phosphate, and bis[5-{2-(meth)acryloyloxyethoxycarbonyl}heptyl]hydrogen phosphate. Among these, 10-methacryloyloxydecyldihydrogen phosphate is preferred for improving the adhesion of dental polymerizable compositions.

[0037] Examples of (meth)acrylates having a pyrophosphate group include bis[2-(meth)acryloyloxyethyl] pyrophosphate, bis[4-(meth)acryloyloxybutyl] pyrophosphate, bis[6-(meth)acryloyloxyhexyl] pyrophosphate, bis[8-(meth)acryloyloxyoctyl] pyrophosphate, and bis[10-(meth)acryloyloxydecyl] pyrophosphate.

[0038] Examples of (meth)acrylates having a thiophosphate group include 2-(meth)acryloyloxyethyl dihydrogenthiophosphate, 3-(meth)acryloyloxypropyl dihydrogenthiophosphate, 4-(meth)acryloyloxybutyl dihydrogenthiophosphate, 5-(meth)acryloyloxypentyl dihydrogenthiophosphate, 6-(meth)acryloyloxyhexyl dihydrogenthiophosphate, 7-(meth)acryloyloxyheptyl dihydrogenthiophosphate, 8-(meth)acryloyloxyoctyl dihydrogenthiophosphate, 9-(meth)acryloyloxynonyl dihydrogenthiophosphate, 10-(meth)acryloyloxydecyl dihydrogenthiophosphate, and 11-(meth)acryloyloxyundicyl Examples include 12-(meth)acryloyloxide decyl dihydrogenthiophosphate, 13-(meth)acryloyloxytridecyl dihydrogenthiophosphate, 14-(meth)acryloyloxytetradecyl dihydrogenthiophosphate, 15-(meth)acryloyloxypentadecyl dihydrogenthiophosphate, 16-(meth)acryloyloxyhexadecyl dihydrogenthiophosphate, 17-(meth)acryloyloxyheptadecyl dihydrogenthiophosphate, 18-(meth)acryloyloxyoctadecyl dihydrogenthiophosphate, 19-(meth)acryloyloxynonadecyl dihydrogenthiophosphate, and 20-(meth)acryloyloxyicosyl dihydrogenthiophosphate.

[0039] Examples of (meth)acrylates having a carboxyl group include 2-methacryloyloxyethyl succinic acid, 4-(meth)acryloyloxyethyl trimellitic acid, 4-(meth)acryloyloxyethyl trimellitic anhydride, 4-(meth)acryloyloxydecyl trimellitic acid, 4-(meth)acryloyloxydecyl trimellitic anhydride, 11-(meth)acryloyloxy-1,1-undecanedicarboxylic acid, 1,4-di(meth)acryloyloxypyromellitic acid, 2-(meth)acryloyloxyethyl maleic acid, 2-(meth)acryloyloxyethyl phthalic acid, and 2-(meth)acryloyloxyethyl hexahydrophthalic acid. Among these, 2-methacryloyloxyethyl succinic acid is preferred in terms of improving the adhesion of the dental polymerizable composition.

[0040] Examples of (meth)acrylates having a sulfonic acid group include 2-(meth)acrylamide-2-methylpropanesulfonic acid, styrenesulfonic acid, and 2-sulfoethyl (meth)acrylate.

[0041] Examples of (meth)acrylates having a phosphonic acid group include 2-(meth)acryloyloxyethylphenylphosphonate, 5-(meth)acryloyloxypentyl-3-phosphonopropionate, 6-(meth)acryloyloxyhexyl-3-phosphonopropionate, 10-(meth)acryloyloxydecyl-3-phosphonopropionate, 6-(meth)acryloyloxyhexyl-3-phosphonoacetate, and 10-(meth)acryloyloxydecyl-3-phosphonoacetate.

[0042] These (meth)acrylates having acidic groups may be used individually or in combination of two or more.

[0043] Among the (meth)acrylates having acidic groups, those having phosphate groups or carboxyl groups are preferred in terms of the solubility of the smear layer on the tooth surface of the dental polymerizable composition, demineralization of tooth structure, and especially adhesion to enamel.

[0044] The content of (meth)acrylate having an acid group in the dental polymerizable composition is not particularly limited and can be, for example, 0.1% by mass or more and 20% by mass or less, preferably 0.1% by mass or more and 15% by mass or less, and more preferably 0.1% by mass or more and 10% by mass or less. When the content of (meth)acrylate having an acid group in the dental polymerizable composition is 0.1% by mass or more, the adhesion of the dental polymerizable composition to tooth structure is further improved, and when it is 20% by mass or less, the curability of the dental polymerizable composition is improved.

[0045] Examples of (meth)acrylates that do not have an acid group include methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, hydroxypropyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, glycidyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 2-methoxyethyl (meth)acrylate. (T) Acrylate, 2-Ethoxyethyl (meth)acrylate, 2-Methylhexyl (meth)acrylate, 2-Ethylhexyl (meth)acrylate, Benzyl (meth)acrylate, 2-Hydroxy-1,3-Di(meth)acryloyloxypropane, Ethylene glycol di(meth)acrylate, Diethylene glycol di(meth)acrylate, Triethylene glycol di(meth)acrylate, Butylene glycol di(meth)acrylate, Neopentyl glycol di(meth)acrylate, 1,3-Butanediol di( Meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolmethane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, polybutylene glycol di(meth)acrylate, bisphenol A diglycidyl(meth)acrylate, di-2-(meth)acryloyl Examples include oxyethyl-2,2,4-trimethylhexamethylenedicarbamate, 1,3,5-tris[1,3-bis{(meth)acryloyloxy}-2-propoxycarbonylaminohexane]-1,3,5-(1H,3H,5H)triazine-2,4,6-trione, 2,2-bis[4-(3-(meth)acryloyloxy-2-hydroxypropyl)phenyl]propane, and N,N'-(2,2,4-trimethylhexamethylene)bis[2-(aminocarboxy)propane-1,3-diol]tetramethacrylate.

[0046] These (meth)acrylates that do not have acid groups may be used individually or in combination of two or more.

[0047] Among the (meth)acrylates that do not have acid groups, di-2-(meth)acryloyloxyethyl-2,2,4-trimethylhexamethylenedicarbamate and 2-hydroxy-1,3-di(meth)acryloyloxypropane are preferred in terms of improving the mechanical strength of the cured product of the dental polymerizable composition.

[0048] The content of (meth)acrylate without acid groups in the dental polymerizable composition can be 10% by mass or more and 95% by mass or less, preferably 13% by mass or more and 90% by mass or less, and more preferably 15% by mass or more and 80% by mass or less.

[0049] If the content of (meth)acrylate without acid groups in the dental polymerizable composition is 10% by mass or more, the handling properties of the dental polymerizable composition can be improved. Furthermore, if the content of (meth)acrylate without acid groups in the dental polymerizable composition is 95% by mass or less, the mechanical strength of the crude dental polymerizable product can be improved.

[0050] The polymerizable dental composition preferably contains an inorganic filler in addition to the glass composition described above. The components of the inorganic filler are not particularly limited, but examples include colloidal silica, fine silica particles with a hydrophobic surface treatment, aluminum oxide, fluoroaluminosilicate glass, and barium glass. These inorganic fillers may be used individually or in combination of two or more. In the following description, "inorganic filler" refers to an inorganic component other than the glass composition described above.

[0051] The amount of inorganic filler in the dental polymerizable composition is preferably, for example, 0.01% by mass or more and 30% by mass or less, more preferably 0.05% by mass or more and 20% by mass or less, and even more preferably 0.1% by mass or more and 10% by mass or less. When the amount of inorganic filler in the dental polymerizable composition is 0.01% by mass or more, the viscosity of the dental polymerizable composition increases, improving the operability of the dental polymerizable composition. Furthermore, when the amount of inorganic filler in the dental polymerizable composition is 30% by mass or less, the viscosity of the dental polymerizable composition does not become too high, and the high operability of the dental polymerizable composition can be maintained.

[0052] The dental polymerizable composition may also contain at least one other component selected from, for example, chemical polymerization initiators, photopolymerization initiators, and polymerization inhibitors.

[0053] The chemical polymerization initiator is not particularly limited, and for example, thiourea derivatives, vanadium compounds, tertiary amines, or organic peroxides can be used. Thiourea derivatives, vanadium compounds, and tertiary amines function as reducing agents among chemical polymerization initiators. Organic peroxides function as oxidizing agents among chemical polymerization initiators.

[0054] The thiourea derivatives are not particularly limited and include, for example, ethylenethiourea, N-methylthiourea, N-ethylthiourea, N-propylthiourea, N-butylthiourea, N-laurylthiourea, N-phenylthiourea, N-cyclohexylthiourea, N,N-dimethylthiourea, N,N-diethylthiourea, N,N-dipropylthiourea, N,N-dibutylthiourea, N,N-dilaurylthiourea, N,N-diphenylthiourea, N,N-dicyclohexylthiourea, trimethylthiourea, tetramethylthiourea, N-acetylthiourea, N-benzoylthiourea, 1-allyl-3-(2-hydroxyethyl)-2-thiourea, 1-(2-tetrahydrofurfuryl)-2-thiourea, N-tert-butyl-N'-isopropylthiourea, 2-pyridylthiourea, and the like. These thiourea derivatives may be used individually or in combination of two or more. Among these, N-benzoylthiourea is preferred in terms of improving the curability of the dental polymerizable composition.

[0055] The content of the thiourea derivative in the dental polymerizable composition is not particularly limited, but is preferably 0.1% by mass or more and 5% by mass or less, more preferably 0.1% by mass or more and 3% by mass or less, and even more preferably 0.1% by mass or more and 1% by mass or less. When the content of the thiourea derivative in the dental polymerizable composition is 0.1% by mass or more, the curability of the dental polymerizable composition is further improved, and when it is 5% by mass or less, the solubility of the thiourea derivative in the dental polymerizable composition with (meth)acrylate is improved.

[0056] The vanadium compound is not particularly limited and includes, for example, oxovanadium oxalate, vanadylacetylacetonate, vanadium acetylacetonate, vanadyl stearate, vanadium naphthenate, vanadium benzoylacetonate, and two or more may be used in combination. Among these, vanadylacetylacetonate is preferred in terms of the curability of the dental polymerizable composition.

[0057] The vanadium compound content in the dental polymerizable composition is not particularly limited, but is preferably 0.001% by mass or more and 5% by mass or less, more preferably 0.0015% by mass or more and 1% by mass or less, and even more preferably 0.002% by mass or more and 0.1% by mass or less. When the vanadium compound content in the dental polymerizable composition is 0.001% by mass or more, the curability of the dental polymerizable composition is further improved, and when it is 5% by mass or less, the storage stability of the dental polymerizable composition is further improved.

[0058] Tertiary amines are not particularly limited and include, for example, tertiary aliphatic amines and tertiary aromatic amines. Examples of tertiary aliphatic amines include N,N-dimethylaminoethyl methacrylate and triethanolamine. Examples of tertiary aromatic amines include p-dialkylaminobenzoate alkyl, 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.

[0059] Among these, tertiary amines are preferably tertiary aromatic amines, and more preferably alkyl p-dialkylaminobenzoates. 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.

[0060] These tertiary amines may be used individually or in combination of two or more.

[0061] 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 pinan hydroperoxide. These organic peroxides may be used individually or in combination of two or more. Among these, cumene hydroperoxide is preferred in terms of the curability of the dental polymerizable composition.

[0062] The content of organic peroxides in the dental polymerizable 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 organic peroxides in the dental polymerizable composition is 0.01% by mass or more, the curability of the dental polymerizable composition is further improved, and when it is 10% by mass or less, the working time of the dental polymerizable composition is extended.

[0063] The photopolymerization initiator is not particularly limited and includes, for example, camphorquinone, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, benzyl ketal, diacetyl ketal, benzyldimethyl ketal, benzyldiethyl ketal, benzylbis(2-methoxyethyl) ketal, 4,4'-dimethyl(benzyldimethyl ketal), anthraquinone, 1-chloroanthraquinone, 2-chloroanthraquinone, 1,2-benzanthraquinone, 1-hydroxyanthraquinone, 1-methylanthraquinone, 2-ethylanthraquinone, 1-bromore Examples include tetraquinone, 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. These photopolymerization initiators may be used individually 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 polymerizable composition.

[0064] The content of the photopolymerization initiator in the dental polymerizable composition is not particularly limited, but is preferably 0.001% by mass or more and 1% by mass or less, more preferably 0.005% by mass or more and 0.5% by mass or less, and even more preferably 0.01% by mass or more and 0.3% by mass or less. When the content of the photopolymerization initiator in the dental polymerizable composition is 0.001% by mass or more, the curability of the dental polymerizable composition is further improved, and when it is 0.3% by mass or less, the storage stability of the dental polymerizable composition is further improved.

[0065] Examples of polymerization inhibitors include dibutylhydroxytoluene (2,6-di-tert-butyl-p-cresol) and 6-tert-butyl-2,4-xylenol. These polymerization inhibitors may be used individually or in combination of two or more. Among these, dibutylhydroxytoluene is preferred in terms of improving the curability of the dental polymerizable composition.

[0066] The content of polymerization inhibitors in the dental polymerizable composition is not particularly limited, but is preferably 0.001% by mass or more and 5% by mass or less, more preferably 0.005% by mass or more and 1% by mass or less, and even more preferably 0.01% by mass or more and 0.1% by mass or less. When the content of photopolymerization initiators in the dental polymerizable composition is 0.001% by mass or more and 5% by mass or less, the storage stability of the dental polymerizable composition is improved.

[0067] The dosage form of the dental polymerizable composition is not particularly limited and may be, for example, a two-part form containing a first component and a second component, or a single-part form containing only the first component. In the case of a two-part form, the first component and the second component can be mixed together before use. The mass ratio of the first component to the second component is preferably 10:1 to 1:10, and more preferably 1:5 to 5:1.

[0068] In the case of a two-component system, it is preferable that both the first and second components contain the above-mentioned glass composition. This can improve X-ray contrast properties. It is preferable that both the first and second components contain the above-mentioned glass composition and the above-mentioned (meth)acrylate compound, and more preferably that they contain the above-mentioned inorganic filler. Both the first and second components may further contain other components such as the above-mentioned chemical polymerization initiator.

[0069] In the case of a single-component formulation, the first agent naturally contains the above-mentioned glass composition. This allows for high X-ray contrast properties. Preferably, the first agent contains the above-mentioned glass composition and the above-mentioned (meth)acrylate compound, and also contains the above-mentioned inorganic filler. The first agent may further contain other components such as the above-mentioned chemical polymerization initiator.

[0070] The uses of the dental polymerizable composition are not particularly limited, but for example, it can be used in various dental materials. Examples of dental materials include dental cement, dental adhesive, dental temporary filling material, dental primer, dental coating material, dental composite resin, dental hard resin, dental cutting resin material, dental temporary restorative material, dental filling material, and toothpaste. Among these, it is preferably used in dental cement. [Examples]

[0071] The experimental data is described below. In Examples 1-7 and Comparative Example 1, glass plates with the chemical compositions shown in Table 5 were prepared, and the X-ray contrast properties of the glass plates and the refractive index of the glass powder were measured. The chemical composition of the glass plates was measured by X-ray fluorescence analysis. The X-ray contrast properties of the glass plates were measured as described above. The thickness Ts of the glass plates used as test specimens was 1 mm.

[0072] The refractive index of the glass powder was measured using the following procedure. First, glass powder with an average particle size of 1000 nm was prepared by crushing a glass plate. Next, the prepared glass powder was mixed with a liquid having a specific refractive index in a 1:1 (mass ratio) ratio and packed into a transparent tube. Then, the transparent tube was held up to a white LED, and the color of the transmitted light through the transparent tube was observed visually. The refractive index of the liquid that produced green transmitted light through the transparent tube was adopted as the refractive index of the glass powder. Note that if the refractive index of the liquid is lower than that of the glass powder, the color of the transmitted light through the transparent tube will be blue. Also, if the refractive index of the liquid is higher than that of the glass powder, the color of the transmitted light through the transparent tube will be red or yellow.

[0073] When the refractive index of the glass powder was between 1.4600 and 1.5400, the liquid used was either Liquid 1, Liquid 2, or a mixture thereof, as described in Table 1. Both Liquid 1 and Liquid 2 are commonly used as dental materials.

[0074] [Table 1] The mixing ratio (mass ratio) of liquid 1 and liquid 2 was adjusted in 0.5% increments.

[0075] When the refractive index of the glass powder was between 1.5400 and 1.6600, the liquid used was either Liquid 2, Liquid 3, or a mixture thereof, as described in Table 2. Both Liquid 2 and Liquid 3 are commonly used as dental materials.

[0076] [Table 2] The mixing ratio (mass ratio) of liquid 2 and liquid 3 was adjusted in 0.5% increments.

[0077] In Examples 1-7 and Comparative Example 1, the refractive index of the glass powder was 1.4600-1.6600. However, if the refractive index of the glass powder is 1.4500-1.4600, then liquids 1, 4, or mixtures thereof, as described in Table 3, may be used. Both liquids 1 and 4 are commonly used as dental materials.

[0078] [Table 3] The mixing ratio (mass ratio) of liquid 1 and liquid 4 should be adjusted in 5.0% increments.

[0079] Furthermore, if the refractive index of the glass powder is between 1.3300 and 1.4500, then liquids 4, 5, or mixtures thereof, as listed in Table 4, may be used. Both liquids 4 and 5 are commonly used as dental materials.

[0080] [Table 4] The mixing ratio (mass ratio) of liquid 4 and liquid 5 should be adjusted in 0.5% increments.

[0081] While the refractive index of glass powder is measured as described above, the refractive index of glass plates can be measured using the V-block method.

[0082] Table 5 shows the physical properties of the glass plates prepared in Examples 1-7 and Comparative Example 1.

[0083] [Table 5] As shown in Table 5, in Examples 1 to 7, unlike Comparative Example 1, the total content of gadolinium oxide and cesium oxide was 1% by mass or more. Therefore, while suppressing the decrease in X-ray contrast, the barium oxide content could be reduced to less than 30% by mass, and the refractive index could be adjusted to 1.45 or more and less than 1.56.

[0084] Although the glass composition according to the present invention has been described above, the present invention is not limited to the embodiments described above. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope described in the claims. These also naturally fall within the technical scope of the present invention.

Claims

1. It contains at least one of gadolinium (Gd) and cesium (Cs), and silicon (Si), In terms of oxides, the total content of gadolinium oxide and cesium oxide is 1% by mass or more, the gadolinium oxide content is 12% to 30% by mass, and the silicon oxide content is 30% by mass or more. Dental glass composition.

2. The refractive index is 1.50 or more and less than 1.56, The dental glass composition according to claim 1.

3. It is in powder form. The dental glass composition according to claim 1 or 2.

4. In terms of oxides, the cesium oxide content is 8% to 15% by mass. A dental glass composition according to any one of claims 1 to 3.

5. A barium-free, A dental glass composition according to any one of claims 1 to 4.

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