JP2003095836A - Restorative dental material composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a restorative dental material composition excellent in surface lubricative properties and having little shrinkage by polymerization and high strength used for restoring loss of a tooth or teeth caused by dental caries, an external injury and the like. SOLUTION: This restorative dental material composition comprises an organic inorganic composite filler the surface of which is treated with (a) a (meth)acrylate monomer having at least one unsaturated double bond and (b) a mono (meth)acrylate having a cyclic ether structure in the molecule, (c) an inorganic filler of fine particles having 5-50 nm average particle size and (d) a polymerization initiator. The composition preferably consists of 20-65 wt.% ingredient (a), 15-75 wt.% ingredient (b), 1-20 wt.% ingredient (c) and 0.01-8 pts.wt. ingredient (d) based on 100 pts.wt. ingredient (a).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dental restorative material composition which is used for repairing a tooth defect caused by caries, trauma or the like, has excellent surface lubricity, small polymerization shrinkage and high strength.

[0002]

2. Description of the Related Art Conventionally, materials such as metal and amalgam have been used for repairing tooth defects due to caries, trauma, etc.
In recent years, dental restorative material compositions such as composite resins and hard resins, which are capable of obtaining a color tone closer to that of natural teeth as compared with metals, have become widespread. The restoration is performed by applying a dental adhesive to the cavity formed on the tooth and then directly filling the resin material and polymerizing and curing in the cavity by chemical polymerization or photopolymerization, or the oral cavity of the cavity formed on the tooth. Dental restorative material made by taking an internal impression and molding the dental restorative material composition on an intraoral gypsum model produced based on the impression and then polymerizing and curing by heat polymerization, photopolymerization, chemical polymerization It is carried out by an indirect repair method in which it is fixed to the cavity with an adhesive for use.

A dental restorative composition is basically composed of a polymerizable monomer, a filler and a polymerization initiator, but various improvements have been made in pursuit of strength and aesthetics. Conventionally, as a filler used in a dental restorative composition, an inorganic filler such as glass powder having a maximum particle size of 10 to 50 μm has been used. However, the dental restorative material composition using such an inorganic filler having a relatively large particle diameter has a roughened surface of the restorative material and a smooth finished surface similar to that of natural teeth can be obtained in clinical use. There wasn't. Therefore, in order to compensate for this defect and improve surface lubricity, a dental restorative composition using an inorganic filler such as glass powder having a maximum particle size of about 2 μm has been developed. Although the surface smoothness of this dental restorative composition is sufficient, it is difficult to polish and requires skill to obtain a smooth surface, and the proportion of the inorganic filler in the entire composition is high. Although the strength was high, it was brittle and had problems such as fracture clinically.

Further, in order to further improve the surface lubricity, a dental restorative material composition using a fine particle inorganic filler having an average particle diameter of 5 to 50 nm has been developed. However, since these fine particle inorganic fillers have a very large specific surface area, the proportion of the filler in the dental restorative composition is 30 to 6%.
The amount was as small as 0% by weight, and therefore the polymerization shrinkage was large and the physical properties were inferior. As a means for compensating the polymerization shrinkage of this dental restorative material composition, a dental restorative material composition using an organic-inorganic composite filler obtained by mixing and curing a fine particle inorganic filler having an average particle diameter of 5 to 50 nm with a polymerizable monomer and pulverizing the mixture. The thing was developed. Since this organic-inorganic composite filler has a small specific surface area and can be mixed in a large amount, it has small polymerization shrinkage and excellent surface lubricity. However, there is a problem that the bond between the organic-inorganic composite filler and the matrix is weak and the strength is low. Therefore, a surface treatment using an organosilicon compound is also performed to strengthen the bond between the organic-inorganic composite filler and the matrix, but since the proportion of the organic component on the surface of the organic-inorganic composite filler is high, it only acts on the inorganic substance. The surface treatment with a non-organic silicon compound has a low effect, and there has been a problem that the end portion of the dental restorative material is chipped.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a dental restorative material composition having a high mechanical strength, in a dental restorative material composition using an organic-inorganic composite filler having excellent surface lubricity and small polymerization shrinkage. The challenge is to provide.

[0006]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have found that a mono (meta) having a specific molecular structure for strengthening the bond between the organic-inorganic composite filler and the matrix. ) When surface-treating the organic-inorganic composite filler with acrylate, a specific molecular structure acts on the organic component of the organic-inorganic composite filler, while the polymerizable unsaturated double bond of the (meth) acrylate is formed. The present inventors have completed the present invention by clarifying that the bonding at the interface between the organic-inorganic composite filler and the matrix is strengthened by polymerizing and bonding with the matrix monomer of the dental restorative composition.

That is, the present invention comprises (a) a (meth) acrylate monomer having at least one unsaturated double bond,
(b) an organic-inorganic composite filler surface-treated with a mono (meth) acrylate containing a cyclic ether structure in the molecule,
(c) a fine particle inorganic filler having an average particle size of 5 to 50 nm,
A dental restorative composition comprising (d) a polymerization initiator, wherein (a) a monomer of (meth) acrylate having at least one unsaturated double bond: 20 to 65
Wt%, (b) an organic-inorganic composite filler surface-treated with a mono (meth) acrylate having a cyclic ether structure in the molecule: 15 to 75 wt%, and (c) an average particle size of 5 to 5
Fine particle inorganic filler of 0 nm: 1 to 20% by weight, and (d) polymerization initiator: 0.1 to 100 parts by weight of (meth) acrylate monomer having at least one unsaturated double bond.
It is preferable that the content of the (b) organic-inorganic composite filler is surface-treated with 2 to 20% by weight of mono (meth) acrylate having a cyclic ether structure in the molecule based on the whole. It was also determined that it is preferable that the mono (meth) acrylate having a cyclic ether structure in the molecule is a compound represented by a specific chemical formula.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The monomer of the (meth) acrylate having at least one unsaturated double bond, which is the component (a) used in the present invention, is a general monomer which has been conventionally used in dentistry. It is possible to use, specifically, methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-
Hydroxypropyl (meth) acrylate, 2-hydroxy-1,3-di (meth) acryloxypropane, n-
Butyl (meth) acrylate, isobutyl (meth) acrylate, butoxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, glycidyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2 -Ethylhexyl (meth) acrylate, benzyl (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, triethylene glycol tri (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 , Trimethylolmethane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, polyoxytetraethylene glycol di (meth) acrylate, 2,2-bis {(meth) acryloxyphenyl} Propane, 2,2-bis [4- {2-hydroxy-3- (meth) acryloxypropoxy} phenyl] propane, 2,2-bis {4-
(Meth) acryloxydiethoxyphenyl} propane,
2,2-bis {4- (meth) acryloxypolyethoxyphenyl} propane and di-2- (meth) acryloxyethyl-2,2,4-as (meth) acrylate having a urethane bond in the molecule. Examples include trimethylhexamethylene dicarbamate. In addition, those containing many unsaturated double bonds can also be used. These (meth) acrylate monomers having at least one unsaturated double bond can be used alone or in admixture of two or more. In addition, it is used for the dental restorative composition according to the present invention.
The amount of the (meth) acrylate monomer having at least one unsaturated double bond, which is the component (a), is preferably 20 to 65% by weight based on the whole dental restorative composition. When the amount of these monomers is less than 20% by weight, it becomes difficult to uniformly disperse the filler, which will be described later, and as a result, the physical properties of the dental restorative material composition after curing are likely to deteriorate. On the other hand, when it exceeds 65% by weight, the amount of the filler to be described later is relatively reduced, so that the polymerization shrinkage is increased and the mechanical strength of the dental restorative material composition after curing is also lowered.

The organic-inorganic composite filler surface-treated with a mono (meth) acrylate having a cyclic ether structure in the molecule, which is the component (b) used in the present invention, has been conventionally used in a dental restorative composition. The organic-inorganic composite filler described above is surface-treated with a mono (meth) acrylate containing a cyclic ether structure in the molecule. In this organic-inorganic composite filler, for example, an inorganic filler such as a fine particle inorganic filler is uniformly dispersed and mixed in a monomer of (meth) acrylate having at least one unsaturated double bond as the component (a). It can be obtained by polymerizing and curing and crushing it later. As the fine particle filler, a silane compound produced by spray pyrolysis is preferable, and colloidal silica is particularly preferable. The proportion of the inorganic filler in the organic-inorganic composite filler used in the present invention is not particularly limited as long as the inorganic filler can be uniformly dispersed in the monomer, but preferably 30
Is about 90% by weight. Further, as the inorganic filler in the organic-inorganic composite filler, it is possible to use an inorganic filler which has been treated with an organosilicon compound to reduce silanol groups on the surface. The blending amount of the organic-inorganic composite filler surface-treated with the mono (meth) acrylate having a cyclic ether structure in the molecule, which is the component (b) used in the dental restorative composition according to the present invention, is the same. 15-75% by weight with respect to the total composition
Is preferred. If it is less than 15% by weight, it is difficult to obtain effects such as reduction of polymerization shrinkage and improvement of strength, and if it is more than 75% by weight, it becomes difficult to uniformly disperse the organic-inorganic composite filler in the dental restorative composition.

The mono (meth) acrylate used for the surface treatment of the organic-inorganic composite filler surface-treated with the mono (meth) acrylate having a cyclic ether structure in the molecule which is the component (b) used in the present invention is It is a compound having a cyclic ether structure such as epoxy and one (meth) acryloyl group in the molecule. Among them, compounds represented by the following chemical formulas are preferable, and among mono (meth) acrylates containing a cyclic ether structure in the molecule represented by the following chemical formula, tetrahydrofurfuryl (meth) acrylate, glycidyl (meth) having a small molecular weight (n = 0) ) Acrylate is most preferred.

[0011]

[Chemical 2]

The method of surface-treating the organic-inorganic composite filler surface-treated with the mono (meth) acrylate having a cyclic ether structure in the molecule which is the component (b) used in the present invention is a cyclic ether structure in the molecule. Is not particularly limited as long as it is a method in which the mono (meth) acrylate containing the compound uniformly acts on the entire organic-inorganic composite filler, and for example, while stirring the organic-inorganic composite filler with a stirrer, a cyclic ether in the molecule which is the surface treatment agent A method of adding a structure-containing mono (meth) acrylate by dropping or spraying, after dispersing the organic-inorganic composite filler and the mono (meth) acrylate containing a cyclic ether structure in the molecule which is the surface treatment agent in a suitable solvent, There is a method of removing the solvent.

The mono (meth) acrylate having a cyclic ether structure in the molecule, which is the surface treatment agent, is surface-treated at a concentration of 2 to 20% by weight based on the whole organic-inorganic composite filler after the surface treatment. Is preferably performed. If it is less than 2% by weight, it becomes difficult to treat the whole organic-inorganic composite filler, and if it exceeds 20% by weight, the surface of the organic-inorganic composite filler is a mono (meta-meta) containing a cyclic ether structure in the surplus molecule. This is because an acrylate layer is easily formed, and in that case, the crosslink density after polymerization is low.

The fine particle inorganic filler having an average particle size of 5 to 50 nm, which is the component (c) used in the present invention, is preferably a silane compound produced by spray pyrolysis, and particularly preferably colloidal silica. In the present invention, a fine particle inorganic filler having an average particle size of 5 to 50 nm, which is the component (c), is added to prevent liquid separation. The content thereof is preferably 1 to 20% by weight based on the whole dental restorative composition. This is because if it is less than 1% by weight, it is difficult to obtain the effect of preventing liquid separation, and if it exceeds 20% by weight, polymerization shrinkage becomes large. Further, as the fine particle inorganic filler having an average particle diameter of 5 to 50 nm, it is possible to use one which has been subjected to a treatment for reducing the silanol groups on the surface with an organic silicon compound.

The polymerization initiator which is the component (d) used in the present invention is a polymerized form of the (meth) acrylate monomer having at least one unsaturated double bond which is the component (a),
It is appropriately selected and added depending on whether it is a heat polymerization type, a chemical polymerization type or a photopolymerization type, and the addition amount is at least one unsaturated double bond which is the component (a) in the dental restorative composition. It is preferably 0.01 to 8 parts by weight with respect to 100 parts by weight of the (meth) acrylate monomer having This is because if the amount is less than 0.01 parts by weight, it is difficult to obtain the effect as a polymerization initiator, and if the amount exceeds 8 parts by weight, the curing tends not to change.

The polymerization initiator as the component (d) is mainly used when the polymerization form of the (meth) acrylate monomer having at least one unsaturated double bond as the component (a) is a heat polymerization type. Organic peroxides, azo compounds and the like are used. As the organic peroxide, diacyl peroxides having an aromatic ring and peroxyesters regarded as esters of perbenzoic acid are preferable, and examples thereof include benzoyl peroxide, 2,4-dichlorobenzoyl peroxide and m. -Tolyl peroxide, t-butyl peroxybenzoate, di-t-butyl peroxyisophthalate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, 2,5-dimethyl-2,5- Di {(o
-Benzoyl) benzoylperoxy} hexane etc.,
As the azo compound, azobisisobutyronitrile and the like are effective, and in addition, organometallic compounds such as tributylboron and the like are also used.

When the (meth) acrylate monomer having at least one unsaturated double bond as the component (a) is chemically polymerized, the polymerization initiator as the component (d) is an organic peroxide. A combination of an oxide and an aromatic tertiary amine may be mentioned. These are used by dividing a dental restorative material composition into two components and blending one composition with an organic peroxide and the other composition with an aromatic tertiary amine. As the organic peroxide, the same substance as the above-mentioned organic polymer used in the heat polymerization type can be used. As a tertiary amine,
A tertiary amine in which a nitrogen atom is directly substituted on the aromatic ring is preferable, and N, N-dimethyl-p-toluidine, N, N-dimethylaniline, N-methyl-N-β-hydroxyaniline, N, N-di ( β-hydroxyethyl) -aniline,
N, N-di (β-hydroxyethyl) -p-toluidine, N, N-di (β-hydroxypropyl) -aniline,
N, N-di (β-hydroxypropyl) -p-toluidine, N, N-dimethylaminobenzoic acid ethyl ester, N, N-
Isoamyl dimethylaminobenzoate and the like are effective.

As the polymerization initiator as the component (d) when the polymerization form of the (meth) acrylate monomer having at least one unsaturated double bond as the component (a) is a photopolymerization type, a sensitizing agent is used. A combination of agents and reducing agents is commonly used.
As the sensitizer, camphorquinone, benzyl, diacetyl, benzyldimethyl ketal, benzyl diethyl ketal, benzyl di (2-methoxyethyl) ketal,
4,4′-dimethylbenzyl-dimethyl ketal, anthraquinone, 1-chloroanthraquinone, 2-chloroanthraquinone, 1,2-benzanthraquinone, 1-hydroxyanthraquinone, 1-methylanthraquinone,
2-ethylanthraquinone, 1-bromoanthraquinone, 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, isopropyl ether, benzoin isobutyl ether, benzophenone,
Bis (4-dimethylaminophenyl) ketone, 4,4 '
-Bisdiethylaminobenzophenone, derivatives of acylphosphine oxide, compounds containing an azido group, and the like, which can be used alone or in combination of two or more.

As the reducing agent, a tertiary amine is generally used, and N, N-dimethyl-p-toluidine, N, N-
Dimethylaminoethyl methacrylate, triethanolamine, methyl N, N-dimethylaminobenzoate, N,
Ethyl N-dimethylaminobenzoate and isoamyl N, N-dimethylaminobenzoate are preferred. Examples of other reducing agents include benzoyl peroxide, sodium sulfinate derivative, and organometallic compounds. In the case of a photopolymerization type dental restorative composition, the polymerization reaction can be achieved by irradiating with actinic rays such as ultraviolet rays or visible rays.
As the light source, various types of ultrahigh pressure, high pressure, medium pressure or low pressure mercury lamps, chemical lamps, carbon arc lamps, metal halide lamps, fluorescent lamps, tungsten lamps, xenon lamps, argon ion lasers and the like can be used.

In the dental restorative material composition according to the present invention, other known ultraviolet absorbers, colorants, polymerization inhibitors, discoloration inhibitors, antibacterial agents, surfactants and the like are used in trace amounts, if necessary. It

[0021]

Example An organic-inorganic composite filler was prepared by the following method. The compounds used in the examples and comparative examples are described as follows. (a) A compound corresponding to a monomer of (meth) acrylate having at least one unsaturated double bond UDMA: di-2-methacryloxyethyl-2,2,4
-Trimethylhexamethylene dicarbamate NPG: Neopentyl glycol dimethacrylate 3G: Triethylene glycol dimethacrylate TMPT: Triethylene glycol trimethacrylate Bis-GMA: 2,2-bis [4- (2-hydroxy-3-methacryloxypropoxy) Phenyl] propane Bis-MPEPP: 2,2-bis {4-methacryloxypolyethoxyphenyl} propane (b) Surface of organic-inorganic composite filler surface-treated with mono (meth) acrylate containing cyclic ether structure in molecule Compounds corresponding to treating agents and conventional surface treating agents THFMA: tetrahydrofurfuryl methacrylate GMA: glycidyl methacrylate γ-MPS: γ-methacryloxypropyltrimethoxysilane (d) corresponding to a polymerization initiator Compound CQ: camphorquinone DMEMA: N, N- dimethylaminoethyl methacrylate BPO: benzoyl peroxide 2NPT: N, N-dimethyl -p- toluidine AZO: azobisisobutyronitrile

<Organic-Inorganic Composite Filler A> UDMA and NP
A mixture of 99% by weight of G in a weight ratio of 7: 3 and 1% by weight of AZO and a fine particle inorganic filler having an average particle size of 16 nm (trade name: Aerosil R972, manufactured by Nippon Aerosil Co., Ltd.)
Were mixed at a weight ratio of 7: 3, heated and cured at 100 ° C. for 2 hours, and pulverized to have an average particle size of 15 μm. While stirring the obtained powder with a stirrer, THFMA was added dropwise to obtain an organic-inorganic composite filler A. The surface treatment concentrations with THFMA are summarized in Table 1.

<Organic-Inorganic Composite Filler B> UDMA and NP
A mixture of 99% by weight of G in a weight ratio of 7: 3 and 1% by weight of AZO and a fine particle inorganic filler having an average particle diameter of 30 nm (trade name: Aerosil 50, manufactured by Nippon Aerosil Co., Ltd.) are mixed in a weight ratio of 7: 3. Then, the mixture was cured by heating at 100 ° C. for 2 hours and pulverized to have an average particle size of 15 μm. While stirring the obtained powder with a stirrer, THFMA was added dropwise to obtain an organic-inorganic composite filler B. The surface treatment concentrations with THFMA are summarized in Table 1.

<Organic-Inorganic Composite Filler C> Bis-MPE
A mixture of PP and 3G in a weight ratio of 5: 5 99% by weight, AZ
O 1% by weight of the mixed solution and fine particle inorganic filler having an average particle size of 16 nm (trade name: Aerosil R972, manufactured by Nippon Aerosil Co., Ltd.) were mixed at a weight ratio of 6: 4 and heat-cured at 100 ° C. for 2 hours to obtain an average. It was crushed to a particle size of 8 μm. GMA was added dropwise while stirring the obtained powder with a stirrer to obtain an organic-inorganic composite filler C. The surface treatment concentrations by GMA are summarized in Table 1.

<Organic-Inorganic Composite Filler D> TMPT 99
Wt%, AZO 1 wt% mixed solution and average particle size 16 nm
100 parts by mixing the fine particle inorganic filler (trade name: Aerosil R972, manufactured by Nippon Aerosil Co., Ltd.) in a weight ratio of 7: 3.
The mixture was heat-cured at 2 ° C. for 2 hours and pulverized to an average particle size of 15 μm. GMA was added dropwise while stirring the obtained powder with a stirrer to obtain an organic-inorganic composite filler D. The surface treatment concentrations by GMA are summarized in Table 1.

Example 1 (a) UDMA as a monomer of (meth) acrylate having at least one unsaturated double bond in an amount of 20% by weight and 3% by weight.
10% by weight of G (polymerization initiator is 10
(Prepared by dissolving 0.5 parts by weight of CQ which is a photosensitizer and 1 part by weight of DMEMA which is a reducing agent to 0 parts by weight)
And (b) mono (meta) containing a cyclic ether structure in the molecule
60% by weight of the organic-inorganic composite filler A surface-treated with THFMA which is an acrylate, and (c) 1 g of Aerosil R972 having an average particle diameter of 16 nm as a fine particle inorganic filler.
0% by weight was kneaded with a kneader in a dark room to obtain a dental restorative material composition. The following test was performed on the obtained dental restorative composition.

<3-Point Bending Strength and Bending Strain Energy Test> The dental restorative composition was pressed onto a 2 mm × 2 mm × 25 mm mold with a glass plate through cellophane, and in the case of the photopolymerization type, visible light was applied. Both sides are irradiated with light for 3 minutes each with an irradiator (trade name: Labolite LV-II, made by GC), and in the case of the chemical polymerization type, an equal amount of each dental restorative composition is measured and filled in a mold. Then, let it stand in the room for 15 minutes to polymerize, and in the case of the heating polymerization type, high pressure (500 Kg / cm ² ) by the dry heat method.
Polymerization was carried out at 100 ° C. for 30 minutes. 3 samples obtained
After being immersed in water at 7 ° C for 24 hours, a universal tester (trade name: Autograph, manufactured by Shimadzu Corporation) has a span of 20 mm and a crosshead speed of 1 mm / min. The three-point bending test was conducted at the same time, and the bending strain energy was also calculated. The results are summarized in Table 1.

<Surface Roughness Test> The dental restorative composition was pressed against a mold having a diameter of 15 mm and a thickness of 2 mm with a glass plate through cellophane, and the same as the three-point bending strength and bending strain energy test. It was polymerized and cured by the above method. The surface of the obtained sample is 600, 1000, 1500, 2000
No. 1 silicon carbide paper is used for polishing, and finally alumina particles with a particle size of 0.5 μm are used for mirror finish polishing, followed by a surface roughness tester (trade name: Surfcoder S
Ten-point average roughness Rz was measured with E-40H, manufactured by Kosaka Laboratory Ltd.). The results are summarized in Table 1.

Examples 2 to 11 and Comparative Examples 1 to 3 Dental restorative material compositions of Examples 2 to 11 and Comparative Examples 1 to 3 were prepared according to the formulations shown in Table 1 in the same manner as in Example 1. The test was conducted. The results are summarized in Table 1.

[0030]

[Table 1]

[0031]

As is clear from Table 1, the dental restorative composition according to the present invention has a three-point bending strength as compared with Comparative Example 1 using only the conventional fine particle inorganic filler as the filler. Comparative Example 3 which is a conventional dental restorative composition using a surface treating agent which is excellent and has excellent surface roughness as compared with Comparative Example 2 which also uses glass powder. It can be confirmed that the dental restorative composition has higher strength while maintaining high surface smoothness as compared with the above. Further, the dental restorative material composition according to the present invention has a problem that the bending strain energy becomes high due to the strong bond between the organic-inorganic composite filler and the matrix, and the end portion of the dental restorative material is chipped. Was also solved. The value of the dental restorative material composition according to the present invention having such excellent characteristics to contribute to the field of dentistry is extremely great.

Claims (4)

[Claims] 1. An organic-inorganic surface-treated with (a) a monomer of (meth) acrylate having at least one unsaturated double bond and (b) a mono (meth) acrylate containing a cyclic ether structure in the molecule. A dental restorative composition comprising a composite filler, (c) a fine particle inorganic filler having an average particle size of 5 to 50 nm, and (d) a polymerization initiator. 2. A (meth) acrylate monomer having (a) at least one unsaturated double bond: 20 to 65% by weight, and (b) a mono (meth) acrylate containing a cyclic ether structure in the molecule. Surface-treated organic-inorganic composite filler: 15 to 75% by weight, (c) average particle size of 5 to 50 n
Fine particle inorganic filler of m: 1 to 20% by weight, and (d) polymerization initiator: having at least one unsaturated double bond (meta)
0.01 per 100 parts by weight of acrylate monomer
The dental restorative composition according to claim 1, which comprises -8 parts by weight. 3. The organic-inorganic composite filler (b), which is surface-treated with 2 to 20% by weight of mono (meth) acrylate having a cyclic ether structure in the molecule based on the whole. The dental restorative composition according to item 1. 4. The dental restorative composition according to any one of claims 1 to 3, wherein the mono (meth) acrylate having a cyclic ether structure in the molecule is a compound represented by the following chemical formula. [Chemical 1]