Patent Description:
The present invention relates to a dental polymerizable composition.

Patent Document <NUM> discloses a polymerizable composition containing, for example, a first component including a (meth)acrylate and an organic peroxide, and a second component including a (meth)acrylate, a vanadium compound, and a thiourea derivative, wherein the polymerizable composition can be used under wet conditions such as in an oral cavity in a dental treatment.

<CIT> discloses a dental polymerizable composition comprising: a first component containing a (meth)acrylate free of an acid group, a (meth)acrylate having a carboxyl group, a basic filler, and an organic peroxide; and a second component containing a (meth)acrylate free of an acid group, a polymerization accelerator, and a thiourea derivative.

The curability of the polymerizable composition described above may be improved by mixing a (meth)acylate having a phosphate group.

However, there is a problem that, for example, when basic fillers such as barium glass powders, which is capable of improving the X-ray contrast of a cured product, is added, the basic filler adsorbs the (meth)acrylate having a phosphate group, thereby reducing the storage stability of the polymerizable composition.

One aspect of the invention is to provide a dental polymerizable composition that exhibits improved curability and storage stability even if a dental polymerizable composition includes a basic filler.

One aspect of the invention is a dental polymerizable composition according to the appended claims.

Next, an embodiment for carrying out the present invention will be described.

A dental polymerizable composition of the present invention contains a first component including a (meth)acrylate free of an acid group, a (meth)acrylate having a carboxyl group, a basic filler, and an organic peroxide; and a second component including a (meth)acrylate having free of an acid group, a vanadium compound, and a thiourea derivative.

In the present specification and claims, a (meth)acrylate refers to a compound (e.g., monomer, oligomer, prepolymer) having one or more methacryloyloxy groups and/or acryloyloxy groups (hereinafter referred to as (meth)acryloyloxy groups).

The second component may further include a basic filler. In this case, the basic filler included in the second component may be the same as or different from the basic filler included in the first component.

Examples of forms of the first component and the second component include a paste and the like.

The mass ratio of the first component and the second component of the dental polymerizable composition of the present embodiment is typically within the range of from <NUM>:<NUM> to <NUM>:<NUM>.

The dental polymerizable composition of the present embodiment is typically used by kneading the first and second components.

The dental polymerizable composition of the present embodiment can be applied to dental cements and the like.

Hereinafter, components constituting a dental polymerizable composition of the present embodiment will be described.

The (meth)acrylate free of an acid group preferably has two or more (meth)acryloyloxy groups.

Examples of the (meth)acrylates free of 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, <NUM>-hydroxyethyl (meth)acrylate, <NUM>-hydroxypropyl (meth)acrylate, <NUM>-hydroxypropyl (meth)acrylate, <NUM>-methoxyethyl (meth)acrylate, <NUM>-ethoxyethyl (meth)acrylate, <NUM>-methylhexyl (meth)acrylate, <NUM>-ethylhexyl (meth)acrylate, benzyl (meth)acrylate, <NUM>-hydroxy-<NUM>,<NUM>-di(meth)acryloyloxypropane, ethyleneglycol di(meth)acrylate, diethyleneglycol di(meth)acrylate, triethyleneglycol di(meth)acrylate, butyleneglycol di(meth)acrylate, neopentylglycol di(meth)acrylate, <NUM>,<NUM>-butanediol di(meth)acrylate, <NUM>,<NUM>-butanediol di(meth)acrylate, <NUM>,<NUM>-hexanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolmethane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, polybutyleneglycol di(meth)acrylate, bisphenol-A diglycidyl (meth)acrylate, ethoxylated bisphenol-A di(meth)acrylate, di-<NUM>-(meth)acryloyloxyethyl-<NUM>,<NUM>,<NUM>-trimethylhexamethylene dicarbamate, <NUM>,<NUM>,<NUM>-tris[<NUM>,<NUM>-bis{(meth)acryloyloxy}-<NUM>-propoxycarbonylaminohexane]-<NUM>,<NUM>,<NUM>-(<NUM>,<NUM>,<NUM>)triazine-<NUM>,<NUM>,<NUM>-trione, <NUM>,<NUM>-bis[<NUM>-(<NUM>-(meth) acryloyloxy-<NUM>-hydroxypropyl) phenyl] propane, N,N'-(<NUM>,<NUM>,<NUM>-trimethylhexamethylene)bis[<NUM>-(aminocarboxy)propane-<NUM>,<NUM>-diol]tetramethacrylate, and the like. Two or more kinds of (meth)acrylates free of an acid group may be used in combination. Among these, di-<NUM>-(meth)acryloyloxyethyl-<NUM>,<NUM>,<NUM>-trimethylhexamethylene dicarbamate, ethoxylated bisphenol-A di(meth)acrylate, neopentyl glycol di(meth)acrylate, and <NUM>-hydroxy-<NUM>,<NUM>-di(meth)acryloyloxypropane are preferably used in terms of the mechanical strength of the cured product of the dental polymerizable composition of the present embodiment.

The content of the (meth)acrylate free of an acid group in the dental polymerizable composition of the present embodiment is preferably <NUM> to <NUM>% by mass and further preferably <NUM> to <NUM>% by mass, improving the workability with the dental polymerizable composition of the present embodiment when the content of the (meth)acrylate in the dental polymerizable composition of the present embodiment is <NUM>% by mass or more and <NUM>% by mass or less.

The (meth)acrylate having a carboxyl group preferably has two or more carboxyl groups.

Alternatively, acid chlorides, alkali metal salts, and amine salts of (meth)acrylates having carboxyl groups may be used instead of (meth)acrylate having a carboxyl group.

Examples of the(meth)acrylates having carboxyl groups include <NUM>-methacryloyloxyethyl succinic acid, (meth)acrylic acid, <NUM>-(meth)acryloyloxyethyl trimellitic acid, <NUM>-(meth)acryloyloxyethyl trimellitic anhydride, <NUM>-(meth)acryloyloxy trimellitic acid, <NUM>-(meth)acryloyloxydecyl trimellitic anhydride, <NUM>-(meth)acryloyloxy-<NUM>,<NUM>-undecanedicarboxylic acid, <NUM>,<NUM>-di(meth)acryloyloxy pyromellitic acid, <NUM>-(meth)acryloyloxyethyl maleic acid, <NUM>-(meth)acryloyloxyethyl phthalic acid, <NUM>-(meth)acryloyloxyethyl hexahydrophthalic acid, and the like. Among these, <NUM>-methacryloyl oxyethylsuccinic acid and (meth)acrylic acid are preferably used in terms of storage stability of the dental polymerizable composition of the present embodiment.

The (meth)acrylate having a carboxyl group may be used alone or in combination with two or more kinds.

The content of the (meth)acrylate having a carboxyl group in the dental polymerizable composition of the present embodiment is <NUM> to <NUM>% by mass and preferably <NUM> to <NUM>% by mass. When the content of (meth)acrylate having a carboxyl group in the dental polymerizable composition of the present embodiment is <NUM> to <NUM>% by mass, improving the curability of the dental polymerizable composition of the present embodiment.

Also, for the same reason as above, the content of the (meth)acrylate having a carboxyl group in the first component is preferably <NUM> to <NUM>% by mass and further preferably <NUM> to <NUM>% by mass.

The dental polymerizable composition of the present embodiment preferably does not contain a (meth)acrylate having acid groups other than carboxyl groups (e.g., phosphate, pyrophosphate, thiophosphate, sulfonate, phosphonate). This improves the storage stability of the dental polymerizable composition of the present embodiment.

A basic filler is glass powders containing barium, strontium or lanthanum.

The glass powders containing barium, strontium, or lanthanum are barium glass powder, strontium glass powder, lanthanum glass powder, barium boroaluminosilicate glass powder, strontium boroaluminosilicate glass powder, lanthanum aluminosilicate glass powder, strontium fluoroaluminosilicate glass powder, barium fluoroaluminosilicate glass powder, and lanthanum fluoroaluminosilicate glass powder. Two or more kinds of the glass powders containing barium, strontium, or lanthanum may be used in combination. Among these, barium glass powder is preferably used in terms of an X-ray contrast of a cured product of the dental polymerizable composition of the present embodiment.

The basic filler may be treated with a surface treatment agent such as a silane coupling agent and the like.

The content of the basic filler in the dental polymerizable composition of the present embodiment is preferably <NUM> to <NUM>% by mass and further preferably <NUM> to <NUM>% by mass. When the content of the basic filler in the dental polymerizable composition of the present embodiment is <NUM>% by mass or more, improving the X-ray contrast of the cured product of the dental polymerizable composition of the present embodiment. When the content of the basic filler in the dental polymerizable composition of the present embodiment is <NUM>% by mass, improving the workability of the dental polymerizable composition of the present embodiment.

An organic peroxide functions as an oxidizer for a chemical polymerization initiator.

Examples of the organic peroxides include benzoyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, t-amyl hydroperoxide, <NUM>,<NUM>,<NUM>,<NUM>-tetramethylbutyl hydroperoxide, <NUM>,<NUM>-dimethyl-<NUM>,<NUM>-di(hydroperoxy)hexane, p-diisopropylbenzene monohydroperoxide, p-methane hydroperoxide, pinane hydroperoxide, and the like. Two or more kinds of the organic peroxides may be used in combination. Among these, cumene hydroperoxide is preferably used in terms of curability of the dental polymerizable composition of the present embodiment.

The content of the organic peroxide in the dental polymerizable composition of the present embodiment is preferably <NUM> to <NUM>% by mass and further preferably <NUM> to <NUM>% by mass. When the content of the organic peroxide in the dental polymerizable composition of the present embodiment is <NUM>% by mass or more and <NUM>% by weight or less, improving the curability of the dental polymerizable composition of the present embodiment.

For the same reason as above, the content of the organic peroxide in a first component is preferably <NUM> to <NUM>% by mass and further preferably <NUM> to <NUM>% by mass.

A vanadium compound functions as a polymerization accelerator.

Examples of the vanadium compounds include oxovanadium oxalate, vanadyl, acetylacetonate, vanadium acetylacetonate, vanadyl stearate, vanadium naphthenate, vanadium benzoyl acetonate, and the like. Two or more kinds of the vanadium compounds may be used in combination. Among these, vanadyl acetylacetonate is preferably used in terms of curability of the dental polymerizable composition of the present embodiment.

The content of the vanadium compound in the dental polymerizable composition of the present embodiment is preferably from <NUM> to <NUM>% by mass and further preferably from <NUM> to <NUM>% by mass. When the content of the vanadium compound in the dental polymerizable composition of the present embodiment is <NUM>% by mass or more, improving the curability of the dental polymerizable composition of the present embodiment. When the content of the vanadium compound in the dental polymerizable composition of the present embodiment is <NUM>% by mass or less, improving the storage stability of the dental polymerizable composition of the present embodiment.

Also, for the same reasons as above, the content of the vanadium compound in a second component is preferably <NUM> to <NUM>% by mass and further preferably <NUM> to <NUM>% by mass.

A thiourea derivative functions as a reducing agent of a chemical polymerization initiator.

The thiourea derivatives are ethylene thiourea, N-methylthiourea, N-ethylthiourea, N-propylthiourea, N-butylthiourea, N-lauryl thiourea, N-phenylthiourea, N-cyclohexylthiourea, N,N-dimethyl thiourea, N,N-diethylthiourea, N,N-dipropylthiourea, N,N-dibutylthiourea, N,N-dilauryl thiourea, N,N-diphenylthiourea, N,N-dicyclohexylthiourea, trimethylthiourea, tetramethyl thiourea, N-acetylthiourea, N-benzoyl thiourea, <NUM>-allyl-<NUM>-(<NUM>-hydroxyethyl)-<NUM>-thiourea, <NUM>-(<NUM>-tetrahydrofurfuryl)-<NUM>-thiourea, N-tert-butyl-N'-isopropylthiourea, and <NUM>-pyridylthiourea. Two or more kinds of the thiourea derivatives may be used in combination. Among these, N-benzoyl thiourea is preferably used in terms of curability of the dental polymerizable composition of the present embodiment.

The content of the thiourea derivative in the dental polymerizable composition of the present embodiment is preferably <NUM> to <NUM>% by mass and further preferably <NUM> to <NUM>% by mass. When the content of the thiourea derivative in the dental polymerizable composition of the present embodiment is <NUM>% by mass or more, improving the curability of the dental polymerizable composition of the present embodiment. When the content of the thiourea derivative in the dental polymerizable composition of the present embodiment is <NUM>% by mass or less, improving the solubility of the thiourea derivative in the dental polymerizable composition of the present embodiment with respect to (meth)acrylate.

Also, for the same reason as above, the content of the thiourea derivative in the second component is preferably <NUM> to <NUM>% by mass and further preferably <NUM> to <NUM>% by mass.

The second component may further contain a tertiary amine.

The tertiary amine functions as a reducing agent in a chemical polymerization initiator.

The tertiary amine may be either a tertiary aliphatic amine or a tertiary aromatic amine, but is preferably a tertiary aromatic amine, particularly alkyl p-dialkylaminobenzoate.

The tertiary aliphatic amines include, for example, N,N-dimethylaminoethylmethacrylate, triethanolamine, and the like.

Examples of the alkyl p-dialkylaminobenzoates include methyl p-dimethylaminobenzoate, ethyl p-dimethylaminobenzoate, propyl p-dimethylaminobenzoate, amyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, ethyl p-diethylaminobenzoate, propyl p-diethylaminobenzoate, and the like.

Examples of tertiary aromatic amines other than the alkyl p-dialkylaminobenzoate include <NUM>-dimethylamino-<NUM>-methylcoumarin, N,N-dimethylaniline, N,N-dibenzylaniline, N,N-dimethyl-p-toluidine, N,N-diethyl-p-toluidine, N,N-bis(<NUM>-hydroxyethyl)-p-toluidine, N,N,<NUM>,<NUM>,<NUM>-pentamethylaniline, N,N,<NUM>,<NUM>-tetramethylaniline, N,N-diethyl-<NUM>,<NUM>,<NUM>-trimethylaniline, and the like.

The tertiary amine may be used alone or in combination with two or more kinds.

The first and/or second components may further contain a polymerization inhibitor, a photopolymerization initiator, a filler other than a basic filler, and the like.

Examples of the polymerization inhibitors include dibutyl hydroxytoluene (<NUM>,<NUM>-di-tert-butyl-p-cresol), <NUM>-tert-butyl-<NUM>,<NUM>-xylenol, and the like. Two or more kinds of polymerization inhibitors may be used in combination.

Examples of the photopolymerization initiators include camphorquinone, phenylbis (<NUM>,<NUM>,<NUM>-trimethylbenzoyl) phosphineoxide, <NUM>,<NUM>,<NUM>-trimethylbenzoyl diphenylphosphine, benzyl ketal, diacetyl ketal, benzyl dimethyl ketal, benzyl diethyl ketal, benzyl bis(<NUM>-methoxyethyl) ketal, <NUM>,<NUM>'-dimethyl (benzyl dimethyl ketal), anthraquinone, <NUM>-chloroanthraquinone, <NUM>-chloroanthraquinone, <NUM>,<NUM>-benzanthraquinone, <NUM>-hydroxyanthraquinone, <NUM>-methylanthraquinone, <NUM>-ethylanthraquinone, <NUM>-bromoanthraquinone, thioxanthone, <NUM>-isopropylthioxanthone, <NUM>-nitrothioxanthone, <NUM>-methylthioxanthone, <NUM>,<NUM>-dimethylthioxanthone, <NUM>,<NUM>-diethylthioxanthone, <NUM>,<NUM>-diisopropylthioxanthone, <NUM>-chloro-<NUM>-trifluoromethylthioxanthone, thioxanthone-<NUM>,<NUM>-dioxide, thioxanthone-<NUM>-oxide, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzophenone, bis(<NUM>-dimethylaminophenyl)ketone, <NUM>,<NUM>'-bis(diethylamino)benzophenone, and the like. Two or more kinds of photopolymerization initiators may be used in combination.

Examples of fillers other than the basic filler include anhydrous silicic acid powder, fumed silica, alumina powder, glass powder (for example, barium glass powder, fluoroaluminosilicate glass powder), and the like. Two or more kinds of fillers may be used in combination.

The filler other than the basic filler may be treated with a surface treatment agent such as a silane coupling agent and the like.

Hereinafter, examples of the present invention will be described, but the present invention is not limited to the examples.

Paste <NUM> was prepared by mixing a methacrylate free of an acid group, a methacrylate having an acid group, an organic peroxide, a filler, and a polymerization inhibitor according to the amounts [% by mass] indicated in Table <NUM>.

The abbreviations indicated in Table <NUM> are as follows.

Paste <NUM> was prepared by mixing UDMA (<NUM>% by mass), EBDMA (<NUM>% by mass), and NPG (<NUM>% by mass) as a methacrylate free of an acid group; vanadyl acetylacetonate (<NUM>% by mass) as a vanadium compound; N-benzoyl thiourea (<NUM>% by mass) as a thiourea derivative; filler <NUM> (<NUM>% by mass) and filler <NUM> (<NUM>% by mass); ethyl p-dimethylaminobenzoate (<NUM>% by mass) as a tertiary amine; camphorquinone (<NUM>% by mass) and <NUM>,<NUM>,<NUM>-trimethylbenzoyl diphenylphosphine oxide (<NUM>% by mass) as a photopolymerization initiator; and dibutyl hydroxytoluene (<NUM>% by mass) as a polymerization inhibitor.

Next, the curability of pastes <NUM> and <NUM> (dental polymerizable compositions), storage stability and X-ray contrast of the cured products were evaluated.

The curability of the dental polymerizable composition was evaluated in accordance with ISO <NUM>:<NUM>.

Specifically, paste <NUM> and paste <NUM> were kneaded in a mass ratio of <NUM>:<NUM>, and then the kneaded paste was filled into a polyethylene tube having an inner diameter of <NUM> and a height of <NUM> to prepare a test piece. A thermocouple was then used to record the temperature change of the test piece and determine an initial setting time.

The criteria for curability of dental polymerizable compositions are as follows.

Accelerated testing was performed to evaluate the storage stability of dental polymerizable compositions.

Specifically, the pastes <NUM> and <NUM> were stored at <NUM> for <NUM> days, and then a setting time was determined in the same manner as the initial setting time.

The criteria for storage stability of dental polymerizable compositions are as follows.

A X-ray contrast of the dental polymerizable composition was evaluated in accordance with ISO <NUM>:<NUM> as follows.

Paste <NUM> and Paste <NUM> were kneaded in a mass ratio of <NUM>:<NUM>. A polyester sheet was then placed at the bottom of a fluoropolymer ring having an inner diameter of <NUM> and a thickness of <NUM>. The kneaded dental polymerizable composition was filled in the ring. Next, a polyester sheet was placed on top of the ring, and then the kneaded dental polymerizable composition was photocured in press-welded contact with a glass plate to obtain a test piece.

A digital X-ray apparatus was used to take simultaneous photographs of the test piece and an aluminum step plate, and the digital image files were transferred to a gray scale value analysis software to measure the average gray scale value of the test piece. Next, the gray scale value was measured in each step of the aluminum step plate. The gray scale value and thickness of each step of the aluminum step plate were then plotted to determine the relationship between the gray scale value and the aluminum thickness. The aluminum thickness corresponding to the gray scale value of the test piece was then determined.

The criteria for X-ray contrast of the cured product of the dental polymerizable composition are as follows.

Table <NUM> indicates the evaluation results of curability, storage stability, and X-ray contrast of the dental polymerizable compositions.

From Table <NUM>, it is apparent that the dental polymerizable compositions of Examples <NUM> to <NUM> have high curability and storage stability, and have high X-ray contrast of the cured products.

In contrast, the dental polymerizable composition of Comparative Example <NUM> has paste <NUM> that does not contain a (meth)acrylate having an acid group. Accordingly, the dental polymerizable composition of Comparative Example <NUM> has low curability.

Claim 1:
A dental polymerizable composition comprising:
a first component containing a (meth)acrylate free of an acid group, a (meth)acrylate having a carboxyl group, a basic filler, and an organic peroxide; and
a second component containing a (meth)acrylate free of an acid group, a vanadium compound, and a thiourea derivative,
wherein a content of the (meth)acrylate having the carboxyl group in the dental polymerizable composition is <NUM> to <NUM>% by mass,
wherein the basic filler is one or more selected from barium glass powder, strontium glass powder, lanthanum glass powder, barium boroaluminosilicate glass powder, strontium boroaluminosilicate glass powder, lanthanum aluminosilicate glass powder, strontium fluoroaluminosilicate glass powder, barium fluoroaluminosilicate glass powder, and lanthanum fluoroaluminosilicate glass powder, and
wherein the thiourea derivative is one or more selected from ethylene thiourea, N-methylthiourea, N-ethylthiourea, N-propylthiourea, N-butylthiourea, N-lauryl thiourea, N-phenylthiourea, N-cyclohexylthiourea, N,N-dimethyl thiourea, N,N-diethylthiourea, N,N-dipropylthiourea, N,N-dibutylthiourea, N,N-dilauryl thiourea, N,N-diphenylthiourea, N,N-dicyclohexylthiourea, trimethylthiourea, tetramethyl thiourea, N-acetylthiourea, N-benzoyl thiourea, <NUM>-allyl-<NUM>-(<NUM>-hydroxyethyl)-<NUM>-thiourea, <NUM>-(<NUM>-tetrahydrofurfuryl)-<NUM>-thiourea, N-tert-butyl-N'-isopropylthiourea, and <NUM>-pyridylthiourea.