JP2002138008A - Dental curable composition - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To achieve very good restoration of color tone compatibility with natural teeth, excellent operability, small polymerization shrinkage,
Provided is a dental curable composition which has a high flexural strength of a cured body, and is excellent in surface lubricity and abrasion resistance. SOLUTION: The polymerizable monomer composition has an average particle diameter of 1
A dental curable composition obtained by mixing an organic-inorganic composite filler having a particle size of ２０20 μm, wherein the cured product has the following formula D = {(I ₂₀ / cos ₂₀゜) + (I ₇₀ / cos ₇₀゜)} / (2)
× I ₀ ) (where I _o , I ₂₀ , and I ₇₀ represent a plate-like sample having a thickness of 0.3 mm obtained by curing the dental curable composition, with respect to the surface of the sample. In the case where light is irradiated vertically, it means the light intensity transmitted in the directions of 0 °, 20 ° and 70 ° with respect to the incident direction of light, respectively.) A curable dental composition as described above.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a dental curable composition which can be suitably used as a dental restoration material. More specifically, it has excellent operability, small polymerization shrinkage during polymerization, and furthermore, the strength, surface lubrication, and abrasion resistance of the cured product,
And a dental curable composition having excellent color tone compatibility with natural teeth.

[0002]

2. Description of the Related Art Dental composite restorative materials have rapidly spread as materials for restoring treated teeth because they can impart a color tone close to natural tooth color and are easy to operate. Most of the treatment is performed not only by composite restoration materials but also by restoration of posterior teeth and the like under high occlusal pressure.

[0003] Dental composite restorative materials are generally mainly composed of a polymerizable monomer (monomer), a filler, and a polymerization catalyst. However, the operability of the paste before curing, and the aesthetic and mechanical properties of the cured product. And the like greatly depend on the type, shape, particle size, filling amount and the like of the filler used.

For example, conventionally, a dental composite restoration material containing a relatively large inorganic filler having a particle size of more than several μm has been known. However, the dental composite restoration material has a mechanical strength of a hardened body. Although it has high characteristics, it has poor abrasion and abrasion resistance, and has a problem that a glossy finished surface similar to natural teeth cannot be obtained clinically.

In order to solve this problem, it has been proposed to use inorganic particles having an average particle diameter of 1 μm or less, in particular, inorganic particles having a rounded shape and / or an aggregate thereof, and using an inorganic filler. Lubricity has been greatly improved. However, in a dental composite restoration material using such a fine filler, since the specific surface area of the fine filler is very large, the consistency of the paste before curing becomes high, and the dentist determines the consistency of the paste. In order to adjust to a level that can be used in the oral cavity, the amount of the monomer must be increased, leading to a decrease in operability, an increase in shrinkage due to polymerization, and a decrease in mechanical strength. There was such a problem.

As a method for solving these problems, for example, a method using an organic-inorganic composite filler as disclosed in JP-A-54-107187 has been proposed.
This organic-inorganic composite filler is obtained by previously mixing and polymerizing and curing a fine inorganic powder and a polymerizable monomer, and then pulverizing to a particle size of about several tens to several hundreds μm, By using the organic-inorganic composite filler, while realizing excellent surface lubricity and abrasion resistance, which are characteristics when using a fine filler, the problems of operability and polymerization shrinkage as described above are to some extent. It is possible to solve.

[0007]

However, in the case of the dental composite restoration material using the above-mentioned organic-inorganic composite filler, the color tone after restoration does not always match the color tone of natural teeth, and the aesthetics I was not satisfied with the point.

[0008] That is, in the conventional materials, even if the color and the transparency of the patient's tooth are selected, the tooth color and the texture cannot be accurately expressed after the actual restoration treatment is performed. In some cases, the boundary between the filler and the natural teeth is clearly defined, and there are cases where the user has a strong sense of discomfort. Also,
Dental composite restoration materials using the above-mentioned organic-inorganic composite fillers were not always sufficient in terms of operability and mechanical strength.

Therefore, the present invention has excellent operability, small polymerization shrinkage, high bending strength, excellent surface lubricity and abrasion resistance, and very good color compatibility with natural teeth after restoration. It is an object of the present invention to provide a dental polymerization-curable composition that can be a dental composite restorative that is excellent in the above.

[0010]

Generally, it is said that one of the optical characteristics of a dental composite restoration material that has a great influence on the aesthetics is light diffusion. This light diffusing property is a property that when light is incident on a translucent material such as a dental composite restoration material, the light is refracted and reflected by the filler inside the material, and the light is diffused in various directions, The observed diffuse reflection light has a color tone that reflects the color tone of the translucent material and its background color, so the higher the light diffusion property, the more the effect of blurring the background color of the restoration and the contour between the restoration and the natural tooth It is considered that the color compatibility with natural teeth is high. As an index of the light diffusivity, a diffusivity (D) described later has been proposed, and it can be said that the higher the diffusivity, the higher the light diffusivity.

In order to solve the above-mentioned problems, the present inventors have conducted various studies on the curable composition containing an organic-inorganic composite filler with respect to the effect of the components on the degree of diffusion. As a result, the particle size of the organic-inorganic composite filler, and the difference in the refractive index between the organic-inorganic composite filler and the portion that becomes the matrix of the filler after curing has a large effect on the diffusivity, and by controlling these, the diffusion of the cured product The knowledge that the degree can be adjusted was obtained. Further, as a result of further study based on the findings, the average particle diameter of the organic-inorganic composite filler is set to a specific range, and when the refractive index difference is set to a specific value or more, a high diffusivity is further improved. The present inventors have found that the above objects, such as operability and mechanical strength, can be achieved, and have completed the present invention.

That is, the present invention relates to a dental curable composition comprising an organic-inorganic composite filler having an average particle size of 1 to 20 μm and a polymerizable monomer. The following equation of the body: D = {(I ₂₀ / cos ₂₀゜) + (I ₇₀ / cos ₇₀゜)} / (2
× I ₀ ) (where I _o , I ₂₀ , and I ₇₀ represent a plate-like sample having a thickness of 0.3 mm obtained by curing the dental curable composition, with respect to the surface of the sample. When the light is irradiated vertically, the light intensity transmitted in the directions of 0 °, 20 °, and 70 ° with respect to the incident direction of the light, respectively.) It is a dental curable composition characterized by being at least 01.

The dental curable composition of the present invention can be produced by the following production method of the present invention.

That is, in producing a dental curable composition by mixing a polymerizable monomer composition and an organic-inorganic composite filler having an average particle size of 1 to 20 μm, the refractive index of the organic-inorganic composite filler is It can be manufactured by adjusting the absolute value of the difference between the refractive index of the cured product obtained by curing the monomer composition and the cured product to be 0.01 or more.

Therefore, the dental curable composition of the present invention is a dental curable composition containing an organic-inorganic composite filler and a polymerizable monomer from the viewpoint of the constituent components. It can be said that the organic-inorganic composite filler is a dental curable composition characterized by satisfying the following conditions (1) and (2).

(1) The average particle size is 1 to 20 μm.

(2) Let the refractive index be n_FAnd the dentist
Organic compound in the cured product obtained by curing the curable composition for
Refractive index of matrix part where inorganic composite filler is dispersed
To n _MThen, n_F-N_MAbsolute value of 0.01 or less
Being above.

Although the present invention is not limited by theory, in the present invention, the use of the organic-inorganic composite filler reduces the polymerization shrinkage during the polymerization as in the case of the conventional dental curable composition. In addition to the improved surface lubricity and abrasion resistance of the cured product, the average particle size of the composite filler is larger than the wavelength of visible light (0.4 to 0.7 μm), so that the refractive index of light is refracted and reflected. Effectively occurs, and furthermore, because the difference in the refractive index between the composite filler and the matrix is large, light incident on the cured product is less likely to undergo refraction and reflection at the interface between the composite filler and the matrix, and the diffusivity is reduced. It is thought that the color tone compatibility with natural teeth is improved.

In the dental curable composition of the present invention, the organic-inorganic composite filler comprises a polymerizable monomer and spherical or substantially spherical inorganic particles having an average particle diameter of 0.001 to 1 μm and / or the inorganic or inorganic particles. An organic-inorganic-composite filler obtained by pulverizing a cured product of a polymerizable curable composition containing an aggregate of particles is particularly preferred since it has particularly high surface lubricity and abrasion resistance. Further, the inorganic particles and / or the aggregate of the inorganic particles may be a hydrolyzable organosilicon compound, and the periodic table I, II, III, and IV capable of binding to the hydrolyzable organosilicon compound. The inorganic powder containing an inorganic oxide as a main component obtained by reacting an organic compound of at least one metal selected from the group consisting of metals belonging to the group III is used for obtaining a desired degree of diffusion. It is characterized in that the rate can be easily adjusted and that X-ray contrast can be easily imparted.

In addition, those containing a spherical or substantially spherical inorganic particle having an average particle diameter of 1 μm or less and / or an inorganic filler composed of an aggregate of the inorganic particle are more excellent in the curability paste filling operability. There is a feature that the strength of the cured body is even higher.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION The dental curable composition of the present invention comprises:
It contains an organic-inorganic composite filler (hereinafter, also simply referred to as a composite filler) and a polymerizable monomer. By using an organic-inorganic composite filler as a filler, polymerization shrinkage can be reduced, and the surface lubricity and abrasion resistance of the cured product can be improved. Here, the composite filler means a composite filler of a polymer and inorganic particles, for example, crushing a cured product obtained by curing a polymerizable composition containing a polymerizable monomer and an inorganic powder. Can be manufactured.

The composite filler used in the dental curable composition of the present invention is not particularly limited, but in order to achieve the object of the present invention, the composite filler has an average particle size of 1 to 20 μm and a refractive index of (n). _F) is the refractive index of the matrix portion cured product composite filler obtained by the dental curable composition is cured to the dispersion of the present invention when the n _M, the absolute value of n _F -n _M is 0. It is preferably at least 01.
The method for producing such a composite filler will be described in detail in the following description of a preferred method for producing the dental curable composition of the present invention.

The content of the composite filler in the dental curable composition of the present invention is not particularly limited. However, from the viewpoints of color compatibility and strength of the cured product with natural teeth, the weight basis of the entire dental curable composition is preferred. And 30 to 90% by mass, especially 40 to 7% by mass.
It is preferably in the range of 0% by weight.

As the polymerizable monomer used in the dental curable composition of the present invention, a known polymerizable monomer usable as a dental composite material can be used without any limitation. Examples of suitable polymerizable monomers include polymerizable monomers having a (meth) acryloyl group. Specific examples of such a polymerizable monomer include the following A:
To D are exemplified.

A Monofunctional vinyl monomer Methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, hydroxyethyl methacrylate, tetrahydrofurfuryl methacrylate, glycidyl methacrylate and other methacrylates, and acrylates corresponding to these methacrylates; or acrylic acid, methacrylic acid, p -Methacryloyloxybenzoic acid, N-2-hydroxy-3-methacryloyloxypropyl-N-phenylglycine, 4-methacryloyloxyethyl trimellitic acid, and anhydrides thereof, 6-methacryloyloxyhexamethylenemalonic acid, 10-methacryloyloxy Decamethylenemalonic acid, 2-methacryloyloxyethyl dihydrogen phosphate, 10-methacryloyloxy Kamechi range hydrogen phosphate, 2-hydroxyethyl hydrogen phenyl phosphonate or the like.

B Bifunctional vinyl monomer B-1 Aromatic compound type 2,2-bis (methacryloyloxyphenyl) propane, 2,2-bis [4- (3-methacryloyloxy)
-2-hydroxypropoxyphenyl] propane (hereinafter abbreviated as bis-GMA), 2,2-bis (4-
(Methacryloyloxyphenyl) propane, 2,2-bis (4-methacryloyloxypolyethoxyphenyl)
Propane (hereinafter abbreviated as D-2.6E), 2,2-
Bis (4-methacryloyloxydiethoxyphenyl)
Propane), 2,2-bis (4-methacryloyloxytetraethoxyphenyl) propane, 2,2-bis (4
-Methacryloyloxypentaethoxyphenyl) propane, 2,2-bis (4-methacryloyloxydipropoxyphenyl) propane, 2 (4-methacryloyloxydiethoxyphenyl) -2 (4-methacryloyloxydiethoxyphenyl) propane, 2 ( 4-methacryloyloxydiethoxyphenyl) -2 (4-methacryloyloxyditriethoxyphenyl) propane,
(4-methacryloyloxydipropoxyphenyl)-
2- (4-methacryloyloxytriethoxyphenyl) propane, 2,2-bis (4-methacryloyloxypropoxyphenyl) propane, 2,2-bis (4-
Methacryloyloxyisopropoxyphenyl) propane and acrylates corresponding to these methacrylates; methacrylates such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-chloro-2-hydroxypropyl methacrylate, and acrylates corresponding to these methacrylates. And diadducts obtained by addition of a vinyl monomer having a suitable -OH group and a diisocyanate compound having an aromatic group such as diisocyanate methylbenzene and 4,4'-diphenylmethane diisocyanate.

B-2 Aliphatic Compounds Ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate (hereinafter abbreviated as 3G), butylene glycol dimethacrylate, neopentyl glycol dimethacrylate, propylene glycol dimethacrylate , 1,3-butanediol dimethacrylate, 1,4
-Butanediol dimethacrylate, 1,6-hexanediol dimethacrylate and acrylates corresponding to these methacrylates; 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate,
Methacrylates such as 3-chloro-2-hydroxypropyl methacrylate or a vinyl monomer having an -OH group such as an acrylate corresponding to these methacrylates; hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, diisocyanatomethylcyclohexane, isophorone diisocyanate, methylene bis Diadduct obtained from addition with a diisocyanate compound such as (4-cyclohexyl isocyanate); acrylic acid anhydride, methacrylic anhydride;
1,2-bis (3-methacryloyloxy-2-hydroxypropoxy) ethyl, di (2-methacryloyloxypropyl) phosphate and the like.

C trifunctional vinyl monomers: methacrylates such as trimethylolpropane trimethacrylate, trimethylolethanetrimethacrylate, pentaerythritol trimethacrylate, and trimethylolmethane trimethacrylate; and acrylates corresponding to these methacrylates.

D tetrafunctional vinyl monomers pentaerythritol tetramethacrylate, pentaerythritol tetraacrylate and diisocyanatemethylbenzene, diisocyanatemethylcyclohexane, isophorone diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, methylene bis (4-cyclohexyl isocyanate), 4, 4-diphenylmethane diisocyanate,
Diadduct obtained from addition of a diisocyanate compound such as tolylene-2,4-diisocyanate and glycidol dimethacrylate.

These polymerizable monomers may be used alone or as a mixture of different types.

The content of the polymerizable monomer in the dental curable composition of the present invention is not particularly limited, but from the viewpoint of the filling operation of the curable paste and the strength of the cured product, the entire dental curable composition is hardened. 15 to 99% by mass, and especially 20 to 99% by mass, based on the mass of the composite filler excluding the mass of the composite filler.
Preferably it is in the range of 60% by weight.

The dental curable composition of the present invention also comprises
For the purpose of improving the operability of filling the paste and the strength of the cured product, and adjusting the refractive index, etc., the inorganic filler having an average particle diameter of 1 μm or less and / or an inorganic filler composed of an aggregate of the inorganic particles (hereinafter, referred to as “third” It is also preferable to add a component fine filler).

The shape of the third component fine filler is not particularly limited. However, in order to obtain high surface lubrication and abrasion resistance, inorganic particles having a spherical or substantially spherical shape and / or a coagulated inorganic particle are preferred. It is preferable to use an aggregate. Here, the term “substantially spherical” means that a particle of a particle observed in a unit field of view is rounded by taking a photograph of a filler with a scanning electron microscope (hereinafter abbreviated as SEM), and is orthogonal to its maximum diameter. It means that the average uniformity obtained by dividing the particle diameter in the direction by the maximum diameter is 0.6 or more.

In order to obtain high surface lubricity and abrasion resistance and high mechanical strength, the average particle diameter of the third component fine filler is preferably 0.001 to 0.7 μm, particularly 0 μm. It is preferably from 0.05 to 0.7 μm. Also,
The average particle diameter of the third component fine filler as a whole counted as one particle of the aggregate is 0.0001 to 10
It is preferably 0 μm, particularly preferably in the range of 0.05 to 50 μm. In addition, even if the inorganic filler contains an aggregate having a large particle diameter, the aggregate has an average particle diameter of 1 μm.
In the case of the following aggregates of inorganic particles, the lubricity and abrasion resistance after polymerization and curing do not decrease unlike the case where independent particles having a large particle diameter are added.

In the third component fine filler, the inorganic particles (primary particles) have a coefficient of variation in particle diameter of 0.3 from the viewpoint of surface lubricity and abrasion resistance of the cured product after restoration. It is preferable that the inorganic filler itself is excellent in monodispersibility, and furthermore, it is preferable to reduce the silanol groups on the surface by baking at a temperature of 500 to 1000 ° C. and maintain the surface stability of the inorganic filler itself. It is suitable. These inorganic fillers having different particle size distributions and different materials can be used in combination.

The material of the third component fine filler is not particularly limited, and inorganic compounds such as inorganic oxides such as amorphous silica, silica zirconia, silica titania, barium oxide silica titania, quartz, and alumina can be used. As the material of the inorganic filler, a composite oxide having silica and zirconia as main components is particularly preferably used since a cured product having X-ray contrast properties and more excellent wear resistance can be obtained.

The method for producing these inorganic fillers is not particularly limited, but is advantageous in industrially producing fine particles having a spherical or substantially spherical shape and a monodispersed distribution. Since it is easy to adjust the refractive index and to impart X-ray contrast, it is preferable to manufacture by a so-called sol-gel method. That is, a hydrolyzable organic silicon compound or an organic compound of at least one metal selected from the group consisting of metals of Groups I, II, III, and IV of the Periodic Table, which can be further hydrolyzed, is added. The mixed solution is added to an alkaline solvent in which these organic compounds are dissolved but the reaction product is not substantially dissolved, hydrolysis is carried out to precipitate the reaction product, and a method of drying the precipitate is preferably employed. Is done.

The inorganic oxide obtained by such a method is dried to maintain the surface stability.
It may be fired at a temperature of ° C. At the time of firing, a part of the inorganic oxide may agglomerate. Therefore, it is preferable to use a jet mill, a vibrating ball mill, or the like after loosening the aggregated particles and adjusting the particle size.
Even if such an operation is performed, it is difficult to completely bring the aggregated particles into a state before the aggregation, and when the heat treatment as described above is performed, the inorganic particles having an average particle diameter of 1 μm or less and the aggregates thereof are formed. Is obtained.

The third component fine filler is preferably used after its surface is subjected to a hydrophobic treatment in order to improve the dispersibility in the polymerizable monomer. Such a hydrophobizing treatment is not particularly limited, and a known method is adopted without any limitation. As an example of a typical hydrophobic treatment method, a silane coupling agent as an inorganic filler and a hydrophobizing agent, for example, γ
-Methacryloyloxyalkyltrimethoxysilane,
An organic silicon compound such as hexamethyldisilazane is dispersed and mixed in a suitable solvent using a ball mill or the like, and dried by an evaporator or spray dry.
, A method of heating and distilling the inorganic filler and the hydrophobizing agent in a solvent such as alcohol for several hours, a method of using a titanate coupling agent, and graft polymerization of the polymerizable monomer on the particle surface. And the like. The amount of the hydrophobizing agent used at this time is not particularly limited, and the optimum value may be determined after confirming the mechanical properties and the like of the obtained composite restoration material in advance by experiments, but a preferred range is exemplified. For example, it is in the range of 1 to 30 parts by weight of the above hydrophobizing agent with respect to 100 parts by weight of the inorganic filler.

The addition amount of the third component fine filler is not particularly limited, but from the viewpoint of the above purpose, it is 1 to 1 based on the mass of the entire dental curable composition excluding the mass of the composite filler. 85% by weight, especially 40-80% by weight
Is preferably within the range.

The dental curable composition of the present invention is cured by polymerizing the polymerizable monomer as a component thereof using a polymerization initiator (polymerization catalyst). Therefore, the dental curable composition of the present invention preferably contains a polymerization initiator.

As the polymerization initiator, known polymerization initiators are used without any particular limitation. Generally, different types of polymerization initiators are used depending on the means of polymerizing the polymerizable monomer. The polymerization means, such as ultraviolet light, those by light energy such as visible light, those by the reaction of the peroxide and the accelerator, those by heating, etc., depending on the polymerization means to be employed, various polymerization initiators shown below depending on the polymerization means employed A suitable polymerization initiator may be appropriately selected from among them.

For example, a reaction by light energy (hereinafter referred to as a reaction)
Examples of the polymerization initiator used for photopolymerization) include benzoin alkyl ethers such as benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether; benzyl ketals such as benzyl dimethyl ketal and benzyl diethyl ketal; benzophenone; Benzophenones such as dimethylbenzophenone and 4-methacryloxybenzophenone; α-diketones such as diacetyl, 2,3-pentadionebenzyl, camphorquinone, 9,10-phenanthraquinone and 9,10-anthraquinone; Thioxanthone compounds such as -diethoxythioxanthone, 2-chlorothioxanthone and methylthioxanthone; bis- (2,6
-Dichlorobenzoyl) phenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -2,5-
Dimethylphenylphosphine oxide, bis- (2,
6-dichlorobenzoyl) -4-propylphenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -1-naphthylphosphine oxide, bis (2
Bisacylphosphine oxides such as (4,6-trimethylbenzoyl) -phenylphosphine oxide can be used.

Incidentally, a reducing agent is often added to the photopolymerization initiator. Examples of such a reducing agent include 2- (dimethylamino) ethyl methacrylate, ethyl 4-dimethylaminobenzoate and N-methyldiethanolamine. Examples include aldehydes such as tertiary amines, lauraldehyde, dimethylaminobenzaldehyde, and terephthalaldehyde, and sulfur-containing compounds such as 2-mercaptobenzoxazole, 1-decanethiol, thiosalicylic acid, and thiobenzoic acid.

Examples of the polymerization initiator that can be used for thermal polymerization include benzoyl peroxide, p-chlorobenzoyl peroxide, tert-butylperoxy-2-ethylhexanoate, tert-butylperoxydicarbonate, Peroxides such as diisopropyl peroxydicarbonate, azo compounds such as azobisisobutyronitrile, tributylborane, tributylborane partial oxide, sodium tetraphenylborate, sodium tetrakis (p-fluorophenyl) borate, tetra Boron compounds such as phenylborate triethanolamine salt, 5-butyl barbituric acid, 1-benzyl-5
-Barbituric acids such as phenyl barbituric acid, and sulfinic salts such as sodium benzenesulfinate and sodium p-toluenesulfinate.

In general, in a dental curable composition, photopolymerization is often used as a curing (polymerization) means because of the simplicity of operation at the time of use, and the dental curable composition of the present invention is often used. It is preferable to use a photopolymerization initiator as a polymerization initiator also in the product. Specific examples of particularly preferred photopolymerization initiators among the photopolymerization initiators described above include:
Examples include camphorquinone, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, and bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylphenylphosphine oxide. These polymerization initiators may be used alone or in combination of two or more. The addition amount of the polymerization initiator may be selected according to the purpose, but is usually 0.01 to 30 parts by weight, more preferably 0.1 to 5 parts by weight, per 100 parts by weight of the polymerizable monomer. Used in parts proportions.

In the dental composition of the present invention, known additives can be blended as long as the effect is not significantly impaired. Examples of such additives include a polymerization inhibitor, a pigment, and an ultraviolet absorber. Further, in the dental curable composition of the present invention, for the purpose of further improving the strength of the cured body, an inorganic filler having an average particle diameter larger than 1 μm as long as the surface lubricity and abrasion resistance are not reduced. May be added.

The most characteristic feature of the dental curable composition of the present invention is that the degree of diffusion (D) of the cured product is 0.01 or more. Here, the diffusivity is an index of light diffusivity when the cured body is irradiated with light, and is defined as D in the following formula.

D = {(I ₂₀ / cos ₂₀゜) + (I ₇₀ / cos
70 °)} / (2 × I ₀ ) where I _o , I ₂₀ , and I ₇₀ are the values of a 0.3 mm-thick plate-like sample prepared by curing a dental curable composition. When light is irradiated perpendicularly to the surface of the sample, 0 °, 20 °,
And 70 °. The measurement of the light intensity (luminous intensity) can be easily performed using a goniophotometer. The trigonometric function (cos) means the cosine of the direction in which the luminous intensity was measured, and the unit of the angle is degree (゜).

When the degree of diffusion is 0.01 or more, it is possible to use the dental curable composition of the present invention to perform restoration with high color tone compatibility with natural teeth, that is, restoration with high aesthetics. Becomes In order to obtain higher color compatibility, the degree of diffusion is preferably 0.05 or more,
More preferably, it is 0.08 or more. If the degree of diffusion is too high, it is difficult to have sufficient transparency required as a dental restorative material, so it is preferably 0.5 or less, more preferably 0.3 or less.

The method for producing the dental curable composition of the present invention is not particularly limited. For example, it can be suitably produced by the following method (the production method of the present invention).

That is, a polymerizable monomer composition (also referred to as a matrix raw material composition) and an average particle size of 1 to 20 μm
When producing a dental curable composition by mixing a composite filler, the absolute value of the difference between the refractive index (n _F ) of the composite filler and the refractive index of a cured product obtained by curing the monomer composition. It can be suitably manufactured by adjusting the value to be 0.01 or more.

When a composite filler having an average particle size of less than 1 μm is used, it is difficult to obtain a dental curable composition having a diffusivity of 0.01 or more. Use of a composite filler having an average particle size of more than 20 μm is not preferred because not only is there a problem of operability such as puffiness and stickiness, but also a decrease in mechanical strength occurs. From the viewpoint that the mechanical strength of the cured body is high, the operability of the curable paste is excellent, and a dental restorative material having a higher degree of diffusion can be obtained, an average of 2 to 18 μm, more preferably 5 to 15 μm It is preferable to use a composite filler having a particle diameter.

The composite filler used in the production method of the present invention has an average particle diameter of 1 to 20 μm, and its particle size distribution and production method are not particularly limited as long as the refractive index satisfies the above conditions. Instead, a composite filler manufactured by a known method can be used. However, in order to obtain high surface lubrication and abrasion resistance and high mechanical strength, a polymerizable monomer (hereinafter, referred to as a composite filler raw material) is used. Monomer)) and an average particle diameter of 0.001 to 1 μm, particularly 0.05 to 0.7.
Polymerizable curable composition (also referred to as a composite filler raw material composition) containing spherical or substantially spherical inorganic particles having a particle diameter of μm and / or an inorganic powder (also referred to as a composite filler raw material inorganic filler) composed of an aggregate of the inorganic particles. ) Is preferably obtained by pulverizing the cured product.

At this time, the same inorganic filler as the third component fine filler can be used as the composite filler raw material inorganic filler. That is, they are excellent in monodispersibility such that the coefficient of variation of the primary particle diameter is within 0.3, and the average particle diameter of the inorganic powder as a whole is 0.001 to 20 μm, especially 0.1 to 20 μm.
Inorganic fillers in the range of from 0.5 to 5 μm can be suitably used. In addition, since the above-mentioned inorganic particle has a X-ray contrast property and a hardened body excellent in abrasion resistance is obtained, it is preferable that the inorganic particle is a composite oxide containing silica and zirconia as main components. .

It is to be noted that a plurality of kinds of these inorganic fillers having different particle size distributions and materials can be used as a mixture. Also, regarding the inorganic filler,
It is preferable that the surface is subjected to a hydrophobic treatment by the method described above.

The monomer material of the composite filler is not particularly limited either, and the same polymerizable monomer as described above as the polymerizable monomer which is a component of the curable composition of the present invention may be used alone or in combination of plural kinds. Can be used. The amount ratio of the composite filler raw material inorganic filler and the composite filler raw material monomer in the composite filler raw material composition is not particularly limited, and may be appropriately determined from the viewpoint of the strength and the refractive index of the obtained composite filler. It is preferred that the composite filler raw material inorganic filler is 40 to 95% by mass, particularly 60 to 90% by mass based on the total mass of the composite filler raw material monomer. Further, in order not to significantly reduce the transparency of the cured body of the dental curable composition, the difference between the refractive index of the composite filler raw material inorganic filler and the refractive index of the composite filler raw material monomer is 0.1 or less, more preferably 0 or less. .03
It is preferable to set as follows.

The composite filler raw material composition may contain a polymerization inhibitor, an ultraviolet absorber, a pigment and the like in addition to the composite filler raw material inorganic filler and the composite filler raw material monomer.

After adding a photopolymerization catalyst and / or a chemical polymerization catalyst to the composite filler raw material composition and polymerizing and curing, the obtained cured product is pulverized and classified to obtain a composite filler having a desired average particle diameter. Can be obtained. As a pulverizing method, a ball mill, a vibration mill, a jet mill, or the like can be suitably used, and classification can be performed by a sieve, an air classifier, a water classifier, or the like.

The composite filler thus obtained is
Prior to mixing with the matrix raw material composition, washing, decolorization, and surface treatment may be performed. Decolorization is generally
Disperse the organic-inorganic composite filler in an appropriate solvent, dissolve the peroxide and stir, in some cases by heating,
As the peroxide, a known peroxide can be suitably used.
As the surface treatment method, the above-described procedure for treating the surface of the inorganic filler is similarly applied.

The matrix raw material composition used in the production method of the present invention is obtained by removing the composite filler from the dental curable composition of the present invention, and the cured product of the composition is the dental curable composition of the present invention. In the cured product obtained by curing the conductive composition, the cured product becomes a matrix portion in which the composite filler is dispersed. Therefore, the refractive index of the cured product of the matrix raw material composition is the same as the refractive index (n _M ) of the matrix portion.

As the polymerizable monomer used in the matrix raw material composition, those described above as the polymerizable monomer used in the dental curable composition of the present invention can be used. The matrix raw material composition may be the same as the composite filler raw material monomer, but the absolute value of the difference between the refractive index of the cured product thereof and the refractive index of the cured product of the composite filler raw material monomer is 0.005 to 0. 0.05, more preferably 0.01 to 0.
03, the degree of diffusion (D)
Is easily adjusted to the above value, and the effect of the present invention is particularly preferably exhibited.

It is preferable to add the third component fine filler to the matrix raw material composition in the amount described above. Further, the matrix raw material composition, as long as the effect of the present invention is not impaired, a polymerization inhibitor,
A pigment, an ultraviolet absorber, an inorganic filler having an average particle diameter of more than 1 μm, or the like may be added.

In the production method of the present invention, in order to obtain a high degree of diffusion of at least 0.01, a polymerizable monomer composition and a composite filler having an average particle size of 1 to 20 μm are mixed. upon manufacturing a curable composition, the difference between the refractive index of the composite filler (n _F) and refractive index of the cured product obtained by curing the monomer composition (i.e., n _M) (n _F -
n _M ) has an absolute value (hereinafter abbreviated as Δn) of 0.01.
As described above, it is important to adjust the value to more preferably 0.01 to 0.04, and still more preferably 0.015 to 0.03. Incidentally, the behavior of the optical properties of the dental composite restorative material containing an organic-inorganic composite filler is significantly different from that of a system using only an inorganic filler, and the value of Δn for obtaining such a high degree of diffusion is: It is a value uniquely determined when the organic-inorganic composite filler is used.

Here, Δn can be adjusted to 0.01 or more by changing the composition of the matrix monomer composition, the filler composite filler raw material composition, or both. In general, the refractive index of the matrix monomer composition cured product (n _M) is to increase the content of high refractive index polymer monomer polymer obtained when homopolymerized the polymerizable monomer, Alternatively, it can be increased by adding a third component fine filler that contains a large amount of a component having a high refractive index (a metal oxide such as zirconium, barium, or aluminum) in the third component fine filler that is added as needed. Conversely, increase the content of the polymer monomer having a low refractive index of the polymer obtained when the polymerizable monomer is homopolymerized, or increase the addition amount of the third component fine filler having a low refractive index. Can be lowered. In addition, the refractive index (n _F ) of the composite filler can be similarly controlled by changing the monomer composition of the composite filler raw material and the amount ratio of the monomer of the composite filler raw material and the inorganic filler of the composite filler raw material. It can also be controlled by changing.

In the production method of the present invention, when adjusting the Δn, in order to make the optical texture of the cured body closer to that of natural tooth and to enable a more aesthetic restoration, the transparency of the cured body is required. (Contrast ratio: C = Yb / Yw), it is preferable to determine the refractive indexes of both.

Here, the contrast ratio is one of tristimulus values when a standard black plate (or dark box) and a standard white plate are placed on the back side of a dental restoration material having a thickness of 1 mm, respectively. It is indicated by the ratio of the values (Yb and Yw) and is also an index of transparency. The contrast ratio is the refractive index of each component,
Because it is greatly affected by the blending amount and the particle size of the filler, it cannot be specified unconditionally, but in the case of a general composite resin, the difference between the cured product of the polymerizable monomer and the refractive index of the filler is large. It is known that the more opaque, the smaller the difference in refractive index, the more transparent. Contrast ratio (C = Yb / Yw) of suitably used dental restorative material
Is 0.35 to 0.70, more preferably 0.5 to 0.
65. In order to realize such a contrast ratio, Δn is 0.01, particularly 0.015 or more, and 0.1 or less, more preferably 0.04 or less, and further 0.03 or less. Is preferred.

Further, in the production method of the present invention, it is preferable to adjust the dental restoration material so that the difference between the transparency before curing and the transparency after curing is reduced. This is to facilitate the color matching between the dental restoration and the natural tooth at the time of filling in clinical practice, and to reduce the change in transparency before and after polymerization hardening. Since the change in transparency before and after curing is greatly affected by the particle size of the filler and the amount of each component, it cannot be specified unconditionally, but in general, the refractive index of the matrix raw material composition itself before curing and the composite The absolute value (Δn ′) of the difference from the refractive index (n _F ) of the filler and Δ
It is preferable to make adjustment so that the absolute value of the difference between n becomes small. In the present invention using the composite filler, the adjustment of the refractive index can be easily achieved as compared with the inorganic filler, so that it is particularly preferable.

A predetermined amount of each of the composite filler and the matrix monomer composition having the adjusted refractive index difference (Δn) is taken and sufficiently kneaded, and the paste is defoamed under reduced pressure to remove bubbles. The dental curable composition of the present invention can be obtained.

The use of the dental curable composition of the present invention is not particularly limited, but specific examples include a composite resin for dental filling. A common method of use is to treat the cavity of the tooth to be restored with an appropriate pretreatment material or adhesive, then directly fill the composite resin for dental filling, form it into a tooth shape, and then use a special light irradiator And a method of polymerizing and curing by irradiating strong light.

[0071]

The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples. The inorganic filler, polymerizable monomer, and polymerization initiator used in Examples and Comparative Examples are as follows.

[Inorganic filler] Spherical silica-zirconia; refractive index 1.520, average particle size: 0.2 μm, surface-treated γ-methacryloyloxypropyltrimethoxysilane (hereinafter abbreviated as F-1) spherical silica-zirconia A refractive index of 1.545, an average particle diameter of 0.2 μm, and a surface-treated γ-methacryloyloxypropyltrimethoxysilane (hereinafter abbreviated as F-2) spherical silica-titania; a refractive index of 1.510, an average particle diameter;
0.2 μm, γ-methacryloyloxypropyltrimethoxysilane surface treated product (hereinafter abbreviated as F-3) Spherical silica-barium oxide; refractive index 1.550, average particle size: 0.2 μm, γ-methacryloyloxypropyl tri Methoxysilane surface-treated product (hereinafter abbreviated as F-4) amorphous silica-zirconia; refractive index 1.530, average particle size: 3.0 μm, γ-methacryloyloxypropyltrimethoxysilane surface-treated product (hereinafter F-5) [Polymerizable monomer] 2,2-bis [(3-methacryloyloxy-2-hydroxypropyloxy) phenyl] propane (hereinafter bis)
-Abbreviated as GMA. ) / Triethylene glycol dimethacrylate (hereinafter abbreviated as 3G) (weight ratio 60/40);
Refractive index of cured product 1.546 (hereinafter abbreviated as M-1) 1,6-bis (methacrylethyloxycarbonylamino) trimethyloxane (hereinafter abbreviated as UDMA) / 3
G (weight ratio 70/30); refractive index of cured product 1.510
(Hereinafter abbreviated as M-2) 2,2-bis (4-methacryloyloxypolyethoxyphenyl) propane (hereinafter abbreviated as D-2.6E) / 3
G (weight ratio 70/30); refractive index of cured product 1.550
(Hereinafter abbreviated as M-3).

Bis-GMA / 3G (weight ratio 40/6)
0); refractive index of cured product 1.534 (hereinafter abbreviated as M-4) [Polymerization initiator] azobisisobutyronitrile (hereinafter abbreviated as AIBN) camphorquinone (hereinafter abbreviated as CQ) N, N -Dimethyl-p-toluidine (hereinafter abbreviated as DMPT) In addition, the refractive index, the degree of diffusion of the cured product, the measurement of the bending strength of the cured product, and the surface lubricity of the cured product shown in the following Examples and Comparative Examples The operability of the curable paste was evaluated according to the following method.

(1) Refractive index A refractive index n _D ²⁵ at 25 ° C. was measured using an Abbe refractometer (manufactured by Atago). The refractive index of each inorganic filler was measured by a liquid immersion method. That is, the inorganic filler is dispersed in ethanol, 1-bromonaphthalene is gradually dropped into the slurry, and the refractive index of the dispersion where the boundary between the inorganic filler and the liquid can no longer be visually confirmed is determined by the refractive index of the inorganic filler. Rate. The refractive index of the composite filler was calculated from the refractive index of the cured product of the inorganic filler and the polymerizable monomer, assuming that additivity was satisfied.

(2) Diffusivity A mold having a diameter of 30 mm and a thickness of 0.3 mm is filled with a curable paste, sufficiently photopolymerized and cured, and then taken out of the mold and immersed in water at 37 ° C. for 24 hours. did. The luminous intensity distribution of the transmitted light of this sample piece was measured using a goniophotometer (Murakami Color Research Laboratory, GP-2000). The diffusivity D was calculated according to the following equation.

D = ｛(I ₂₀ / cos ₂₀ °) + (I ₇₀ / co70
°)｝ / (2 × I ₀ ) where I represents the luminous intensity of the light transmitted through the sample, and I _o , I ₂₀ ,
I ₇₀ is 0 degree, 20 degrees,
Indicates the intensity of light in the direction of 70 degrees. The trigonometric function indicates the cosine of the direction in which the luminous intensity was measured, and the unit of the angle is degree.

(3) Surface Lubricity A curable paste was filled in a prismatic form having a width of 2 × 4 × height × 20 mm in length, sufficiently cured by photopolymerization, and then taken out of the form. It was immersed in water at 37 ° C. for 24 hours. After polishing the surface of this sample piece with water-resistant abrasive paper No. 1500, Sof-lex
Finish polishing was performed for one minute with Superfine (manufactured by 3M), and the glossiness of the surface was visually determined. A sample having excellent lubricity was evaluated as ○, a sample having excellent lubricity was evaluated as ◎, and a sample having poor lubricity was evaluated as ×. (4) The curable paste was filled in a prismatic mold having a bending strength of 2 × 2 × 25 mm, sufficiently cured by photopolymerization, and then taken out of the mold and immersed in water at 37 ° C. for 24 hours. The test piece was mounted on a tester (Autograph 5000D, manufactured by Shimadzu Corporation), the distance between supporting points was 20 mm, and the crosshead speed was 0.5 mm.
/ Minute measured the three-point bending strength.

(5) Operability The properties of the curable paste were evaluated based on the following criteria from the viewpoint of ease of filling operation. That is, those with little stickiness and coarseness and easy filling operation were evaluated as ○, particularly those with excellent filling operability were evaluated as 、, and those with strong stickiness and coarseness and difficult to perform the filling operation were evaluated as ×.

Example 1 In a mortar, 100 parts by weight of a polymerizable monomer M-1 in which AIBN was previously dissolved as a polymerization initiator by 0.5% by weight was added to 300 parts by weight of the inorganic filler F-1. And mixed to form a paste. This was heated and polymerized at 95 ° C. under a nitrogen atmosphere for 1 hour. The cured polymer was pulverized using a vibration ball mill, and further subjected to a surface treatment by distilling it with 0.02% by weight of γ-methacryloyloxypropyltrimethoxysilane in ethanol at 90 ° C. for 5 hours. This is defined as a composite filler (refractive index: 1.527, average particle size: 12 μm).

To the polymerizable monomer M-1, 0.5% by weight of a polymerization initiator CQ and 1.5% of DMPT are added and mixed to prepare a uniform polymerizable monomer composition. This was used as a matrix. Next, the above-mentioned organic-inorganic composite filler was placed in an agate mortar as a filler, and the above-mentioned polymerizable monomer composition was gradually added thereto. The mixture was sufficiently kneaded in a dark place to obtain a uniform curable paste. Further, the paste was defoamed under reduced pressure to remove air bubbles, and each physical property was evaluated based on the above methods. The composition is shown in Table 1.

[0081]

[Table 1]

The results are shown in Table 2.

[0083]

[Table 2]

Examples 2 to 6 Organic composite fillers and curable pastes were prepared in the same manner as in Example 1 in accordance with the compositions shown in Table 1, and their physical properties were evaluated.

In all of the compositions of Examples 1 to 6, high diffusivity and high surface lubricity were achieved.

Example 7 The same polymerizable monomer composition as in Example 1 was used except that the filler composition was (A) an organic-inorganic composite filler (60 parts by weight) and (B) an inorganic filler F-2 (40 parts by weight). A curable paste was prepared in place of the mixture, and each physical property was evaluated in the same manner as in Example 1. The composition is shown in Table 1. Table 2 shows the results.

Examples 7 to 16 In the same manner as in Example 5, the organic composite filler and the curable paste were adjusted in accordance with the compositions shown in Table 1, and each physical property was evaluated.

In Examples 7 to 16, an organic-inorganic composite filler having an average particle size of 1 to 20 μm, which is essential for the present invention, and an average particle size of 1 μm
In the examples in which the following inorganic fillers were combined, high diffusivity and high surface lubricity were achieved in all compositions, and the bending strength and paste operability were further improved.

Comparative Example 1 A curable paste was prepared by removing the organic-inorganic composite filler from the composition of Example 5, and the physical properties were evaluated in the same manner as in Example 1. The composition is shown in Table 1. Table 2 shows the results.

In Comparative Example 1, the organic composite filler, which is an essential component, was not blended, and the diffusivity was much lower than that of Example. In addition, the filler filling rate and the bending strength were low, and the operability of the curable paste became large and sticky.

Comparative Examples 2 and 3 With the same composition and the same manufacturing method as the organic-inorganic composite filler shown in Example 1, the organic-inorganic composite filler having a smaller average particle diameter (refractive index 1. 527, average particle size: 0.8 μm), and an organic-inorganic composite filler having a larger average particle size (refractive index: 1.5
24, average particle size: 45 μm). A curable paste was prepared with the same matrix composition as in Example 5 except that the organic-inorganic composite filler was changed to the above-mentioned one, and each physical property was evaluated in the same manner as in Example 1. The composition is shown in Table 1. Table 2 shows the results.

The average particle size of the organic-inorganic composite filler used in Comparative Example 2 was smaller than the range of the present invention, and the diffusivity was significantly reduced as compared with the Example. Furthermore,
The filler filling rate and the bending strength were low, and the operability of the curable paste was also large.

The average particle size of the organic-inorganic composite filler used in Comparative Example 3 was larger than the range of the present invention.
The bending strength was low, and the operability of the curable paste was also large with stickiness and stickiness.

Comparative Example 4 Inorganic filler F-1 which is a raw material of an organic-inorganic composite filler
Was changed to F-2, and otherwise, the organic-inorganic composite filler (refractive index: 1.545, average particle size: 12 μm) was adjusted by the same manufacturing method and composition as in Example 1. A curable paste was prepared with the same matrix composition as in Example 1 except that the organic-inorganic composite filler was changed to the above, and each physical property was evaluated in the same manner as in Example 1. The composition is shown in Table 1. Table 2 shows the results.
It was shown to.

Comparative Example 4 is an example in which the difference in the refractive index between the organic-inorganic composite filler used and the matrix after curing was as small as 0.01 or less, and the diffusivity was significantly reduced as compared with the examples.

Comparative Example 5 A curable paste was prepared in the same manner as in Example 1 except that the organic-inorganic composite filler was changed to the inorganic filler F-5, and each physical property was evaluated in the same manner as in Example 1. The composition is shown in Table 1. Table 2 shows the results.

In Comparative Example 5, the surface lubricating property was significantly inferior to that of Example because the filler used was a particle composed of only inorganic particles.

Claims (6)

[Claims] 1. A dental curable composition comprising an organic-inorganic composite filler having an average particle size of 1 to 20 μm and a polymerizable monomer, wherein the cured product of the dental curable composition is The following formula D = {(I ₂₀ / cos ₂₀゜) + (I ₇₀ / cos ₇₀゜)} / (2
× I ₀ ) (where I _o , I ₂₀ , and I ₇₀ represent a plate-like sample having a thickness of 0.3 mm obtained by curing the dental curable composition, with respect to the surface of the sample. In the case where light is irradiated perpendicularly, it means the light intensity transmitted in directions of 0 °, 20 ° and 70 ° with respect to the incident direction of light, respectively.) A curable dental composition, which is at least 01. 2. A polymerizable monomer composition having an average particle size of 1
When manufacturing a dental curable composition by mixing an organic-inorganic composite filler in the range of ~ 20 μm, the refractive index of the organic-inorganic composite filler and the refractive index of the cured product obtained by curing the monomer composition and The method for producing a dental curable composition according to claim 1, wherein the absolute value of the difference is adjusted to be 0.01 or more. 3. Organic-inorganic composite filler and polymerizable monomer
A dental curable composition comprising:
Machine filler meets the conditions shown in (1) and (2) below.
A dental curable composition characterized by being added. (1) The average particle size is 1 to 20 μm. (2) The refractive index is n_FAnd the dental curable composition
The organic-inorganic composite film in the cured product obtained by curing the product
The refractive index of the matrix portion where _MMade
Sometimes n_F-N_MThe absolute value of
When. 4. A polymer-curable composition comprising an organic-inorganic composite filler comprising a polymerizable monomer and spherical or substantially spherical inorganic particles having an average particle diameter of 0.001 to 1 μm and / or an aggregate of the inorganic particles. The dental curable composition according to claim 1 or 3, which is an organic-inorganic composite filler obtained by pulverizing a cured product of the composition. 5. A method according to claim 1, wherein the inorganic particles contained in the organic-inorganic composite filler and / or the aggregates of the inorganic particles are hydrolysable organic silicon compounds, and a compound of the periodic table which can be bonded to the hydrolyzable organic silicon compounds. 5. An inorganic oxide obtained by reacting an organic compound of at least one metal selected from the group consisting of metals of groups I, II, III, and IV, as a main component. The curable dental composition as described in the above. 6. An inorganic filler comprising spherical or substantially spherical inorganic particles having an average particle size of 1 μm or less and / or an aggregate of the inorganic particles.
The dental curable composition according to claim 3, 4 or 5.