JP7422996B2 - Dental curable composition - Google Patents

Description

The present invention relates to a dental curable composition that can control the external color tone using structural color and has little fading or discoloration, and in particular can be used as a dental filling restoration material for large-scale direct dental restorations. The present invention relates to a curable composition for use.

Conventionally, curable compositions containing inorganic or organic fillers and polymerizable monomers have been used in various fields such as building materials, recording materials, dental materials, and the like. In particular, dental filling and restorative materials have rapidly become popular as materials for restoring teeth damaged by caries, fractures, etc. because they can impart a color tone similar to that of natural teeth and are easy to operate. ing.

Two types of dental filling and restorative materials are widely known: a paste type with a high filler content and high viscosity, and a flowable type with a low filler content and fluidity. Conventionally, paste-type materials have generally been used for tooth restoration because of their ease of polishing and mechanical strength. In recent years, flowable dental filling and restorative materials with excellent abrasiveness and mechanical strength have been developed by making fillers finer and increasing the strength of resins, which can not only be used to repair anterior teeth but also apply high occlusal pressure. It is also used for molars.

The flowable type has the advantage that the surgical procedure is easy because it is possible to directly fill the repaired area using a syringe or the like. In addition, due to its high fluidity, it is easy to fill cavities with complex shapes or deep cavities.

In deep cavity restorations, such as direct molar restorations, it is common to fill and harden the material in multiple stages. This is because polymerization shrinkage occurs as the dental filling and restorative material hardens, and there is a risk that the material will detach from the tooth. On the other hand, in recent years, dental filling and restorative materials with reduced polymerization shrinkage called bulk fill type have also been developed. The bulk fill type allows bulk filling and curing even for large-scale cases such as direct restoration of carious areas of molars.

In recent years, there has been an increasing demand for aesthetic restoration even in direct restoration of molars. Therefore, in order to reproduce the color tone of natural teeth in the bulk-fill type materials mentioned above, we prepare multiple types of materials with different color tones, and from among these, choose the one that best matches the color tone of the actual tooth and adjacent teeth. It is important to select and use the following.

The bulk fill type has limitations in aesthetic restoration because it is used to fill and harden deep cavities all at once. This is because natural teeth consist of highly transparent enamel and opaque, highly saturated dentin, and the color tone varies depending on the area, but with bulk-fill type, both dentin and enamel are exposed within the cavity. This is because it is necessary to repair such deep cavities.

On the other hand, Patent Document 1 discloses a coloring material that develops color using structural color, a photocurable composition using the same, and a dental restoration filling material, which is highly stable against light as weak as ambient light. In order to complete the polymerization in an extremely short time by irradiating active light with a light irradiator, a polymerization catalyst system has been proposed in which a photoacid generator is included in the polymerization catalyst system to speed up the progress of the polymerization reaction. The composition develops a color (structural color) that depends on the particle size of the filler, and a composition that shows red coloring for teeth of A lineage and a composition that shows yellow coloring for teeth of B lineage. has been found to exhibit good tonal compatibility.

International Publication No. 2018/164074

However, according to the studies of the present inventors, depending on the composition, the composition described in Patent Document 1 has good color tone compatibility immediately after curing when filled into a deep cavity, but has good color compatibility after 24 hours. It has been found that there are cases in which it is difficult to obtain color tone compatibility. Although the presence of a photoacid generator in the polymerization catalyst system speeds up the progress of the polymerization reaction, the polymerization does not immediately complete upon irradiation with active light from a light irradiator. Immediately after irradiation with actinic light, the polymerization reaction progresses by about 65% and is almost cured, but after that, the polymerization reaction proceeds slowly over an additional 24 hours and curing is completed (hereinafter referred to as "slow curing after curing immediately after irradiation with actinic light"). The polymerization reaction that progresses is also called post-curing). It is thought that this post-curing increases the transparency of the cured product compared to immediately after curing, making it impossible to obtain good color tone compatibility. That is, the conventional composition described in Patent Document 1 has a large change in transparency due to post-curing, and there is a possibility that the color tone compatibility may become insufficient either immediately after filling or after post-curing.

Therefore, an object of the present invention is to enable restorations that match the color of natural teeth with a single filling restorative material, and even when filled into deep cavities, to match the color of natural teeth both immediately after hardening and after post-hardening. An object of the present invention is to provide a dental curable composition that has good color matching, and a dental filling and restorative material using the composition.

In order to solve the above problems, the present inventors have continued their intensive research. As a result, in a curable composition containing a spherical inorganic filler having a specific particle size and a polymerization catalyst including a photoacid generator, by using fumed silica, the contrast ratio before and after post-curing of the curable composition It has been discovered that the change (ΔYb/Yw) can be controlled and the above problems can be solved, and the present invention has been completed.

That is, the present invention comprises a polymerizable monomer component (A), an inorganic spherical filler (B) having an average particle diameter within the range of 230 to 1000 nm, a polymerization initiator (C), and a fumed product having an average particle diameter of less than 100 nm. Contains silica (D),
The refractive index at 25° C. of the polymer obtained by polymerizing the polymerizable monomer (A): nP is 1.40 to 1.57,
The inorganic spherical filler (B) is a silica/titanium group element oxide composite oxide particle that has a refractive index nF of 1.45 to 1.58 at 25° C. and satisfies the relationship of the formula: nP<nF. and 90% or more of the individual particles constituting the inorganic spherical filler (B) exist within 5% of the average particle diameter,
The blending amount of the inorganic spherical filler (B) with respect to 100 parts by mass of the polymerizable monomer (A) is 50 parts by mass or more and 600 parts by mass or less,
The polymerization initiator (C) is a dental curable composition consisting of a photosensitizing compound (C1), a tertiary amine compound (C2), and a photoacid generator (C3),
This dental curable composition is characterized in that the change in contrast ratio of a 1 mm thick cured product immediately after curing and after being immersed in water at 37° C. for 24 hours is within 0.08. Hereinafter, the period after being immersed in water at 37° C. for 24 hours is also referred to as the period after post-curing.

The photoacid generator (C3) is preferably an aryliodonium salt or an s-triazine compound having a halomethyl group as a substituent.

Preferably, fumed silica (D) is contained in 2 to 40 parts by weight based on 100 parts by weight of the polymerizable monomer component (A).
Further, it is preferable that the loop internal area of the shear rate vs. shear stress curve measured with a rotational viscometer is 10 Pa/s or more and 5000 Pa/s or less.

The dental curable composition of the present invention develops a color that corresponds to the color tone of natural teeth, which varies depending on individual differences and the restoration site, so there is no need to prepare multiple types of dental curable compositions with different colors, Since the contrast ratio changes are small immediately and after post-curing, it is possible to achieve restorations that continue to blend in with natural teeth even in large-scale restoration treatments such as deep cavities. Due to the above effects, the dental curable composition of the present invention can be used particularly as a dental filling and restorative material, and particularly preferably as a dental curable composition for large-scale direct dental restoration. .

The dental curable composition of the present invention comprises a polymerizable monomer component (A), an inorganic spherical filler (B) with an average primary particle size of 230 to 1000 nm, a polymerization initiator (C), and an average primary particle size of It comprises fumed silica (D) that is less than 100 nm.

In the present invention, the refractive index of the polymerizable monomer component (A) and the inorganic spherical filler (B) satisfy the condition of the following formula (1).

nP<nF (1)
In the above formula (1), nP represents the refractive index at 25°C of the polymer of the polymerizable monomer component (A), and nF represents the refractive index at 25°C of the spherical filler (B).

As a result, the composition emits colored light according to the particle size of the spherical filler due to the light interference phenomenon, making it possible to perform a restoration with good color tone compatibility that is close to that of a natural tooth. Here, the relationship between the particle diameter of the spherical filler (B) and the light interference phenomenon is considered to follow Bragg's diffraction conditions.

Natural teeth differ from person to person, and the color tone also varies depending on the area to be restored. However, the curable composition using the light interference phenomenon of the present invention can be applied to various color tones. Specifically, when the chromaticity (hue and saturation) of the underlying tooth is high, external light such as irradiation light is absorbed by the high chromatic background, and dental fillings that utilize light interference phenomena are used. Since light other than colored light (interference light) generated from the repair material is suppressed, colored light can be observed. On the other hand, when the chromaticity of the underlying tooth is low, external light such as irradiation light is scattered and reflected on the background with low chromaticity, and the colored light (interference light), it is canceled out and becomes weak colored light.

Therefore, strong colored light is generated for natural teeth with high chromaticity, and weak colored light is generated for natural teeth with low chromaticity, so it is not possible to show a wide range of color tone compatibility with one type of paste. can. As described above, it is difficult to achieve a technique in which one type of paste matches the color tone of natural teeth regardless of the degree of color, using a paste prepared by blending coloring substances such as pigments.

The dental curable composition of the present invention is characterized by the generation of colored light due to an interference phenomenon, but whether or not the colored light is generated can be determined using a color difference meter under a black background or a white background. This is confirmed by measuring the spectral reflectance characteristics under both conditions. Under a black background, if the above-mentioned conditions are met, a specific reflection spectrum of light in a specific visible spectrum (380-780 nm) can be clearly seen depending on the colored light; This is thought to be because external light (for example, C light source, D65 light source) is absorbed or blocked, and colored light due to interference is emphasized. On the other hand, against a white background, it exhibits a substantially uniform reflectance over substantially the entire range of the visible spectrum, no visible light in the visible spectrum, and is substantially colorless. This is thought to be because, under a white background, the scattered reflected light of external light is strong, making it difficult to observe colored light due to interference.

In order to achieve the effect of excellent color tone compatibility of the present invention, it is important to select the relationship between the refractive indexes so as to satisfy the following formula (1).

nP<nF (1)
As shown in formula (1), in the curable composition of the present invention, the relationship between the refractive index nP of the polymer of the polymerizable monomer component (A) and the refractive index nF of the spherical inorganic filler (B) is nP <nF, and when the refractive index nF of the spherical inorganic filler (B) is high and the refractive index nP of the polymer of the polymerizable monomer component (A) is low, interference light according to the Bragg diffraction conditions will appear. In the opposite case, short wavelength light is more likely to be interfered with, and the resulting colored light has a short wavelength and becomes bluish colored light, which is harmful to the natural tooth cavity formed from the enamel to the dentin. , color compatibility with teeth tends to be poor.

In order to exhibit the effects of the present invention, it is important that the change in contrast ratio (ΔYb/Yw) from immediately after curing to after post-curing is within 0.08. Here, the contrast ratio refers to the contrast ratio of the tristimulus values (X, Y, Z) of light in the CIELAB color space when measuring the color of the cured product of the composition using a color difference meter. It refers to the ratio of Y values, that is, Yb/Yw. Here, Yb refers to the value of Y when colorimetrically measured on a black background, and Yw refers to the value of Y when colorimetrically measured on a white background. The contrast ratio is a measure of the transparency of the cured product, and the larger the value of the contrast ratio, the more opaque it is. The contrast ratio change ΔYb/Yw is the difference between the contrast ratio of the cured product immediately after curing and the contrast ratio of the cured product after post-curing.

If the contrast ratio change (ΔYb/Yw) from immediately after curing to after post-curing is larger than 0.08, the brightness of the filling site after post-curing becomes low when filling a deep cavity, which is an effect of the present invention. It is believed that good color compatibility both immediately after curing and after post-curing is not achieved.

In addition, since the contrast ratio (Yb/Yw) of natural tooth enamel is 0.4 to 0.5, the closer the contrast ratio of the cured product to the contrast ratio of the natural tooth enamel to be restored, the better the aesthetic restoration. becomes possible. Therefore, considering the harmony of the contrast ratio between the restoration part and the natural tooth, the contrast ratio (Yb/Yw) after post-curing is preferably 0.1 to 0.5, more preferably 0.2 to 0.48, and 0. .3 to 0.45 is more preferred.

Each component of the dental curable composition of the present invention will be explained below.

<Polymerizable monomer component (A)>
As the polymerizable monomer component, known ones can be used without particular limitation. From the viewpoint of polymerization rate, radically polymerizable or cationically polymerizable monomers are preferred. Particularly preferred radically polymerizable monomers include (meth)acrylic compounds such as (meth)acrylates shown below, and particularly preferred cationic polymerizable monomers include epoxies and oxetanes. It will be done.

Generally, examples of (meth)acrylates that are preferably used as (meth)acrylic compounds include those shown in (a) to (d) below.

(a) Monofunctional polymerizable monomer (a-i) Methyl (meth)acrylate that does not have acidic groups or hydroxyl groups,
ethyl (meth)acrylate,
n-butyl (meth)acrylate,
2-ethylhexyl (meth)acrylate,
n-lauryl (meth)acrylate,
n-stearyl (meth)acrylate,
Tetrafurfuryl (meth)acrylate,
glycidyl (meth)acrylate,
methoxyethylene glycol (meth)acrylate,
methoxydiethylene glycol (meth)acrylate,
methoxytriethylene glycol (meth)acrylate,
Methoxypolyethylene glycol (meth)acrylate,
ethoxyethylene glycol (meth)acrylate,
ethoxydiethylene glycol (meth)acrylate,
ethoxytriethylene glycol (meth)acrylate,
ethoxypolyethylene glycol (meth)acrylate,
phenoxyethylene glycol (meth)acrylate,
phenoxydiethylene glycol (meth)acrylate,
phenoxytriethylene glycol (meth)acrylate,
phenoxypolyethylene glycol (meth)acrylate,
cyclohexyl (meth)acrylate,
benzyl (meth)acrylate,
isobornyl (meth)acrylate,
Trifluoroethyl (meth)acrylate, etc.

(I-ii) Those having an acidic group (meth)acrylic acid, N-(meth)acryloylglycine,
N-(meth)acryloyl aspartic acid,
N-(meth)acryloyl-5-aminosalicylic acid,
2-(meth)acryloyloxyethyl hydrogen succinate,
2-(meth)acryloyloxyethyl hydrogen phthalate,
2-(meth)acryloyloxyethyl hydrogen malate,
6-(meth)acryloyloxyethylnaphthalene-1,2,6-tricarboxylic acid,
O-(meth)acryloyltyrosine,
N-(meth)acryloyltyrosine,
N-(meth)acryloylphenylalanine,
N-(meth)acryloyl-p-aminobenzoic acid,
N-(meth)acryloyl-o-aminobenzoic acid,
p-vinylbenzoic acid,
2-(meth)acryloyloxybenzoic acid,
3-(meth)acryloyloxybenzoic acid,
4-(meth)acryloyloxybenzoic acid,
N-(meth)acryloyl-5-aminosalicylic acid,
N-(meth)acryloyl-4-aminosalicylic acid, etc. and compounds obtained by converting the carboxyl group of these compounds into an acid anhydride group,
11-(meth)acryloyloxyundecane-1,1-dicarboxylic acid,
10-(meth)acryloyloxydecane-1,1-dicarboxylic acid,
12-(meth)acryloyloxydodecane-1,1-dicarboxylic acid,
6-(meth)acryloyloxyhexane-1,1-dicarboxylic acid,
2-(meth)acryloyloxyethyl-3'-methacryloyloxy-2'-(3,4-dicarboxybenzoyloxy)propyl succinate,
4-(2-(meth)acryloyloxyethyl) trimellitate anhydride,
4-(2-(meth)acryloyloxyethyl) trimellitate,
4-(meth)acryloyloxyethyl trimellitate,
4-(meth)acryloyloxybutyl trimellitate,
4-(meth)acryloyloxyhexyl trimellitate,
4-(meth)acryloyloxydecyl trimellitate,
4-(meth)acryloyloxybutyl trimellitate,
6-(meth)acryloyloxyethylnaphthalene-1,2,6-tricarboxylic anhydride,
6-(meth)acryloyloxyethylnaphthalene-2,3,6-tricarboxylic anhydride,
4-(meth)acryloyloxyethylcarbonylpropionoyl-1,8-naphthalic anhydride,
4-(meth)acryloyloxyethylnaphthalene-1,8-tricarboxylic anhydride,
9-(meth)acryloyloxynonane-1,1-dicarboxylic acid,
13-(meth)acryloyloxytridecane-1,1-dicarboxylic acid,
11-(meth)acrylamidoundecane-1,1-dicarboxylic acid,
2-(meth)acryloyloxyethyl dihydrogen phosphate,
2-(meth)acryloyloxyethylphenyl hydrogen phosphate,
10-(meth)acryloyloxydecyl dihydrogen phosphate,
6-(meth)acryloyloxyhexyl dihydrogen phosphate,
2-(meth)acryloyloxyethyl-2-bromoethyl hydrogen phosphate,
2-(meth)acrylamidoethyl dihydrogen phosphate,
2-(meth)acrylamido-2-methylpropanesulfonic acid,
10-sulfodecyl (meth)acrylate,
3-(meth)acryloxypropyl-3-phosphonopropionate,
3-(meth)acryloxypropylphosphonoacetate,
4-(meth)acryloxybutyl-3-phosphonopropionate,
4-(meth)acryloxybutylphosphonoacetate,
5-(meth)acryloxypentyl-3-phosphonopropionate,
5-(meth)acryloxypentylphosphonoacetate,
6-(meth)acryloxyhexyl-3-phosphonopropionate,
6-(meth)acryloxyhexylphosphonoacetate,
10-(meth)acryloxydecyl-3-phosphonopropionate,
10-(meth)acryloxydecylphosphonoacetate,
2-(meth)acryloxyethyl-phenylphosphonate,
2-(meth)acryloyloxyethylphosphonic acid,
10-(meth)acryloyloxydecylphosphonic acid,
N-(meth)acryloyl-ω-aminopropylphosphonic acid,
2-(meth)acryloyloxyethylphenyl hydrogen phosphate,
2-(meth)acryloyloxyethyl 2'-bromoethyl hydrogen phosphate,
2-(meth)acryloyloxyethylphenylphosphonate, etc.

(I-iii) 2-hydroxyethyl (meth)acrylate having a hydroxyl group,
3-hydroxypropyl (meth)acrylate,
4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate,
10-hydroxydecyl (meth)acrylate,
propylene glycol mono(meth)acrylate,
glycerol mono(meth)acrylate,
Erythritol mono(meth)acrylate,
N-methylol (meth)acrylamide,
N-hydroxyethyl (meth)acrylamide,
N,N-(dihydroxyethyl)(meth)acrylamide, etc.

(b) Bifunctional polymerizable monomer (b-i) Aromatic compound-based 2,2-bis(methacryloyloxyphenyl)propane,
2,2-bis[(3-methacryloyloxy-2-hydroxypropyloxy)phenyl]propane,
2,2-bis(4-methacryloyloxyphenyl)propane,
2,2-bis(4-methacryloyloxypolyethoxyphenyl)propane,
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-methacryloyloxytriethoxyphenyl)propane,
2(4-methacryloyloxydipropoxyphenyl)-2-(4-methacryloyloxytriethoxyphenyl)propane,
2,2-bis(4-methacryloyloxypropoxyphenyl)propane,
2,2-bis(4-methacryloyloxyisopropoxyphenyl)propane and acrylates corresponding to these methacrylates;
-OH group-containing vinyl monomers such as methacrylates such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and 3-chloro-2-hydroxypropyl methacrylate, or acrylates corresponding to these methacrylates, and diisocyanate methylbenzene, 4,4 diaducts obtained from addition with diisocyanate compounds having aromatic groups, such as '-diphenylmethane diisocyanate;
Di(methacryloxyethyl)diphenylmethane diurethane, etc.

(Ro-ii) Aliphatic compound-based ethylene glycol dimethacrylate,
diethylene glycol dimethacrylate,
triethylene glycol dimethacrylate,
Tetraethylene glycol dimethacrylate,
Neopentyl glycol dimethacrylate,
1,3-butanediol dimethacrylate,
1,4-butanediol dimethacrylate,
1,6-hexanediol dimethacrylate,
and acrylates corresponding to these methacrylates;
Methacrylates such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-chloro-2-hydroxypropyl methacrylate, etc., such as 1,6-bis(methacrylethyloxycarbonylamino)trimethylhexane, or acrylates corresponding to these methacrylates. Diaduct obtained from the adduct of a vinyl monomer having an -OH group such as, and a diisocyanate compound such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, diisocyanate methylcyclohexane, isophorone diisocyanate, methylene bis(4-cyclohexyl isocyanate);
1,2-bis(3-methacryloyloxy-2-hydroxypropoxy)ethyl and the like.

(c) trifunctional polymerizable monomer trimethylolpropane trimethacrylate,
trimethylolethane trimethacrylate,
pentaerythritol trimethacrylate,
Methacrylates such as trimethylolmethane trimethacrylate and acrylates corresponding to these methacrylates.

(d) Tetrafunctional polymerizable monomer pentaerythritol tetramethacrylate,
Pentaerythritol tetraacrylate;
Diisocyanate compounds such as diisocyanate methylbenzene, diisocyanate methylcyclohexane, isophorone diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, methylene bis(4-cyclohexyl isocyanate), 4,4-diphenylmethane diisocyanate, tolylene-2,4-diisocyanate, and glycidol diisocyanate. Diaduct etc. obtained from adduct with methacrylate.

A plurality of types of these (meth)acrylate polymerizable monomers may be used in combination as necessary.

Furthermore, if necessary, polymerizable monomers other than the above-mentioned (meth)acrylate monomers may be used.

In the present invention, as the polymerizable monomer component (A), in order to adjust the physical properties (mechanical properties and adhesiveness to tooth substance) of the cured product of the dental curable composition, a plurality of types of polymerizable monomers are generally used. In this case, the type and amount of the polymerizable monomer is adjusted so that the refractive index of the polymerizable monomer component (A) at 25°C is in the range of 1.38 to 1.55. It is desirable to set the following from the viewpoint of the refractive index difference with the spherical inorganic filler (B). That is, in the curable composition of the present invention, the spherical inorganic filler (B) is a silica/titanium group element oxide complex oxide whose refractive index can be easily adjusted, and the refractive index nF is determined by the silica content. Using the formula 1.45 to 1.58, and making sure that the refractive index nP of the polymer obtained from the polymerizable monomer component (A) is in the range of 1.40 to 1.57, (1) should be satisfied , but by setting the refractive index of the polymerizable monomer component (A) in the range of 1.38 to 1.55, it is easy to make nP within the above range. Ru. In addition, there are cases where multiple types of polymerizable monomers are used as the polymerizable monomer component (A), and in this case, the refractive index of the polymerizable monomer component (A) It is sufficient that the refractive index of the mixture of the polymerizable monomers falls within the above range, and the individual polymerizable monomers do not necessarily need to fall within the above range.

Note that the refractive index of the polymerizable monomer or the cured product of the polymerizable monomer can be determined at 25° C. using an Abbe refractometer.

<Spheroidal inorganic filler (B)>
Dental filling and restorative materials contain various fillers such as inorganic powders and organic powders, but the curable composition of the present invention contains an average primary A spherical inorganic filler (B) having a particle size of 230 to 1000 nm is blended. The dental curable composition of the present invention is characterized in that the constituent filler is spherical and has a narrow particle size distribution. Colored light due to interference is produced when the constituent particles are regularly aggregated. Therefore, since the spherical inorganic filler (B) constituting the present invention has a uniform spherical shape and a narrow particle size distribution, colored light is generated due to interference. On the other hand, in the case of amorphous particles produced by pulverization or the like, the shape is non-uniform and the particle size distribution is wide, so they are not regularly accumulated and colored light due to interference is not generated.

As mentioned above, the spherical inorganic filler (B) has an average primary particle diameter of 230 to 1000 nm, and more than 90% (number) of the individual particles constituting the spherical inorganic filler (B) are average primary particles. It is important that it exists within a range of 5% before and after the diameter. In other words, the spherical inorganic filler (B) is composed of a plurality of primary particles, and more than 90% of the total number of primary particles are in a range of 5% before and after the average particle diameter of the plurality of primary particles. This means that there are several primary particles. The appearance of colored light due to interference is due to the fact that diffraction interference occurs in accordance with the Bragg condition and light of a specific wavelength is emphasized.When particles of the above particle size are blended, the curable composition The cured product begins to emit yellow to red colored light. From the viewpoint of further enhancing the effect of producing colored light due to interference, the average primary particle diameter of the spherical inorganic filler (B) is preferably 230 to 800 nm, more preferably 240 to 500 nm, and particularly preferably 260 to 350 nm. be. When a spherical inorganic filler with a particle size in the range of 150 nm to less than 230 nm is used, the colored light obtained is blue, and it is difficult to see the cavity of a natural tooth formed from the enamel to the dentin. The color tone compatibility tends to be poor, and furthermore, when a spherical inorganic filler smaller than 100 nm is used, visible light interference phenomenon is difficult to occur. On the other hand, when a spherical inorganic filler larger than 1000 nm is used, it is expected that light interference phenomenon will occur, but when the curable composition of the present invention is used as a restorative material for dental fillings, precipitation of the spherical inorganic filler may occur. This is not preferable because it causes a decrease in polishing properties.

The curable composition of the present invention emits various colored lights under a black background depending on the particle size of the spherical inorganic filler (B). Therefore, the average primary particle diameter of the spherical inorganic filler (B) may be determined from a range of 230 to 1000 nm so as to obtain the desired colored light. When a spherical inorganic filler with a particle size in the range of 230 nm to 260 nm is used, the colored light obtained is yellowish, and the color of the tooth is in the B-type (red-yellow) category in the shade guide (“VITA Classic”, manufactured by VITA). It is useful for restoration, especially for the restoration of cavities formed from enamel to dentin. When a spherical inorganic filler with a particle size in the range of 260 nm to 350 nm is used, the colored light obtained is red, and the color of the tooth is in the A-type (reddish brown) category in the shade guide (“VITA Classic”, manufactured by VITA). It is useful for restoration, especially for the restoration of cavities formed from enamel to dentin. Since the hue of dentin is often reddish, the present invention uses a spherical filler with an average primary particle diameter in the range of 260 nm to 350 nm, which is widely applicable to restored teeth of various tones. It is the most preferable because it has better properties. On the other hand, when a spherical inorganic filler with a particle size in the range of 150 nm to less than 230 nm is used, as mentioned above, the colored light obtained is blue in color, and is not effective for cavities formed from enamel to dentin. Although it tends to have poor color compatibility with the tooth structure, it is useful for restoring enamel, and is particularly useful for restoring incisal edges.

The property of having a reddish hue against a black background is that if the environment around the hardened material is reddish, even if the environment changes from reddish-yellow to reddish-brown, the brightness and color will remain the same. Both the intensity and hue are well harmonized. Specifically, when the chromaticity (hue and saturation) of the background (base environment) is high, external light such as irradiation light is absorbed by the background with high chromaticity, and light other than colored light from the cured product is absorbed. Colored light can be observed. On the other hand, if the chromaticity of the tooth in the background (base environment) is low, external light such as irradiation light is scattered by the background with low chromaticity and is stronger than the colored light generated from the hardened material, so it is canceled out, resulting in weak coloring. Becomes light. Therefore, strong colored light is generated for a base environment with high chromaticity, and weak colored light is generated for a base environment with low chromaticity, so it harmonizes with a wide range of red-colored surrounding environments. The effect is demonstrated.

In the present invention, the average primary particle diameter of the spherical inorganic filler (B) and the spherical inorganic filler (B2) described below is determined by taking a photograph of the powder with a scanning electron microscope, and determining the particle size observed within the unit field of view of the photograph. It is the average value obtained by selecting 30 or more particles and determining the primary particle diameter (maximum diameter) of each.

Further, in the present invention, the spherical shape may be any substantially spherical shape, and does not necessarily have to be a perfect sphere. Take a photo of particles with a scanning electron microscope, measure the maximum diameter of each particle (30 or more) within the unit field of view, and calculate the average particle diameter in the direction perpendicular to the maximum diameter divided by the maximum diameter. It is sufficient if the degree of symmetry is 0.6 or more, more preferably 0.8 or more.

The spherical inorganic filler (B) may be contained in the dental curable composition of the present invention in any form as long as it satisfies the above-mentioned conditions. For example, the spherical inorganic filler (B) may be used as a powder as it is, or the spherical inorganic filler (B) or an aggregate obtained by agglomerating the spherical inorganic filler (B) may be mixed with a polymerizable monomer and then polymerized and cured. It can be used as an organic-inorganic composite filler prepared by pulverizing. Alternatively, these may be used in combination.

When using the powdered spherical inorganic filler (B) and the organic-inorganic composite filler, the powdered spherical inorganic filler (B) and the spherical inorganic filler (B2) in the organic-inorganic composite filler described below are the same. Alternatively, a different spherical inorganic filler may be used.

The spherical inorganic filler (B) is generally used as a component of dental curable compositions, and examples of such spherical inorganic fillers include amorphous silica, silica/titanium group element oxide-based composite oxides, etc. Examples include particles (silica/zirconia, silica/titania, etc.), quartz, alumina, barium glass, strontium glass, lanthanum glass, fluoroaluminosilicate glass, ytterbium fluoride, zirconia, titania, colloidal silica, and other inorganic powders.

In the present invention, silica/titanium group element oxide composite oxide particles are used as the spherical inorganic filler (B) because it is easy to adjust the refractive index nF of the filler to 1.45 to 1.58 .

In the present invention, silica-titanium group element oxide-based composite oxide particles are composite oxides of silica and titanium group element (group 4 element of the periodic table) oxide, such as silica-titania, silica-zirconia, Examples include silica, titania, and zirconia. Among these, silica-zirconia is preferred because it is possible to adjust the refractive index of the filler and also provide high X-ray opacity. The composite ratio is not particularly limited, but from the viewpoint of imparting sufficient X-ray opacity and setting the refractive index within the preferred range described below, the silica content is 70 to 95 mol%, and the titanium group Preferably, the content of elemental oxides is 5 to 30 mol%. In the case of silica-zirconia, by changing each composite ratio in this way, the refractive index can be changed freely.

In addition, in these silica/titanium group element oxide-based composite oxide particles, a composite of metal oxides other than silica and titanium group element oxides is also allowed as long as the amount is small. Specifically, an alkali metal oxide such as sodium oxide or lithium oxide may be contained within 10 mol%.

The method for producing such silica/titanium group element oxide composite oxide particles is not particularly limited, but in order to obtain the specific spherical filler of the present invention, for example, a hydrolyzable organosilicon compound and a hydrolyzable organic A so-called sol-gel method is preferably employed, in which a mixed solution containing a titanium group metal compound is added to an alkaline solvent and hydrolyzed to precipitate a reaction product.

These silica/titanium group element oxide-based composite oxide particles may be surface-treated with a silane coupling agent. By surface treatment with a silane coupling agent, the organic-inorganic composite filler has excellent interfacial strength with the organic resin matrix (B1) described later. Typical silane coupling agents include organosilicon compounds such as γ-methacryloyloxyalkyltrimethoxysilane and hexamethyldisilazane. There is no particular limit to the amount of surface treatment with these silane coupling agents, and the optimum value may be determined after confirming the mechanical properties of the cured product of the resulting curable composition in advance through experiments. For example, the amount is in the range of 0.1 to 15 parts by mass based on 100 parts by mass of the spherical inorganic filler (B).

As mentioned above, colored light due to interference, scattering, etc., which exhibits good color tone compatibility with natural teeth, can be expressed by the following formula (1):
nP<nF (1)
(In the above formula, nP represents the refractive index at 25°C of the polymer obtained by polymerizing the polymerizable monomer component (A), and nF represents the refractive index at 25°C of the spherical inorganic filler (B).) Obtained if the following is satisfied.

That is, the refractive index of the spherical inorganic filler (B) is higher than the refractive index of the polymer obtained by polymerizing the polymerizable monomer component (A). The difference between the refractive index nF (25°C) of the spherical inorganic filler (B) and the refractive index nP (25°C) of the polymer of the polymerizable monomer component (A) is preferably 0.001 or more. , more preferably 0.002 or more, most preferably 0.005 or more.

Furthermore, when the contrast ratio (Yb/Yw) of the cured product of the curable composition of the present invention is in the range of 0.10 to 0.50 described above, colored light due to interference is clearly expressed and color tone is matched. The refractive index difference between the refractive index nF of the spherical inorganic filler (B) and the refractive index nP of the polymer of the polymerizable monomer component (A) is 0.1 or less, more preferably 0. It is preferable to set it to 05 or less so as not to impair transparency as much as possible.

The amount of the spherical inorganic filler (B) in the present invention is 50 parts by mass to 600 parts by mass based on 100 parts by mass of the polymerizable monomer component (A). By blending 50 parts by mass or more of silica/titanium group oxide composite oxide particles, colored light due to interference, scattering, etc. can be produced satisfactorily. In addition, when using composite oxide particles having a refractive index difference of more than 0.1 with respect to the polymer of the polymerizable monomer component (A), the transparency of the cured product decreases, causing colored light to emit light. There is a possibility that the effect of expression may not be sufficiently expressed. Taking these into consideration, the blending amount of the spherical inorganic filler (B) is preferably 100 parts by mass to 600 parts by mass, and 200 parts by mass to 600 parts by mass, based on 100 parts by mass of the polymerizable monomer component (A). is particularly suitable.

Among the spherical inorganic fillers (B), the refractive index of the silica/titanium group element oxide complex oxide whose refractive index can be easily adjusted is in the range of about 1.45 to 1.58 depending on the silica content. becomes. That is, when using a silica-titanium group element oxide-based composite oxide as the spherical inorganic filler (B), the refractive index of the polymerizable monomer component (A) is within the above range (range of 1.38 to 1.55). ), the refractive index nP of the polymer obtained from the polymerizable monomer component (A) can be set within the range of approximately 1.40 to 1.57. The spherical inorganic filler (B) can be easily selected so as to satisfy 1)). That is, a silica/titanium group element oxide complex oxide containing an appropriate amount of silica (for example, silica/titania or silica/zirconia) may be used.

<Organic-inorganic composite filler>
When the spherical inorganic filler (B) is used in the form of an organic-inorganic composite filler, the organic resin matrix contained in the organic-inorganic composite filler is referred to as the organic resin matrix (B1), and the spherical inorganic filler (B) is referred to as the spherical inorganic filler (B2). That's what it means.

When the spherical inorganic filler (B) is used in the form of an organic-inorganic composite filler, the refractive index difference between the spherical inorganic filler (B2) and the organic resin matrix (B1), which constitute the organic-inorganic composite filler, and the spherical inorganic filler (B2) The organic-inorganic composite filler is added to the curable composition by adjusting the refractive index difference between the polymer and the polymerizable monomer component (A) to satisfy formulas (2) and (3) described below. Even in cases where light diffraction interference occurs according to Bragg's diffraction conditions, and the average primary particle diameter of the spherical inorganic filler (B2) is the same as that of the spherical inorganic filler (B), the spherical inorganic filler (B) alone Colored light with the same wavelength as used in

The spherical inorganic filler (B2) constituting the organic-inorganic composite filler may be the same as or different from the spherical inorganic filler (B) used in powder, but like the spherical inorganic filler (B) used in powder, it is spherical. , the average primary particle diameter is within the range of 230 nm to 1000 nm, and 90% or more of the number of individual particles constituting the spherical inorganic filler (B2) are present in a range of 5% before and after the average primary particle diameter. However, the refractive index nF _B2 of the spherical inorganic filler (B2) is the sum of the refractive index nM _B1 of the organic resin matrix (B1) and the refractive index nF B2 of the spherical inorganic filler (B2), which is expressed by the following formula ( ₂ ). It is important to satisfy the relationship and the relationship between the refractive index nP of the polymer of the polymerizable monomer component (A) and the refractive index nF _B2 of the spherical inorganic filler (B2) shown in the following formula (3). .

nM _B1 <nF _B2 (2)
(In formula (2), nM _B1 represents the refractive index at 25°C of the organic resin matrix (B1) constituting the organic-inorganic composite filler, and nF _B2 represents the refractive index at 25°C of the spherical inorganic filler (B2). .)

nP<nF _B2 (3)
(In formula (3), nP represents the refractive index at 25°C of the polymer of the polymerizable monomer component (A), and nF _B2 represents the refractive index of the spherical inorganic filler (B2) constituting the organic-inorganic composite filler. Represents the refractive index at °C.)

As a result, even when the spherical inorganic filler (B) is used in the form of an organic-inorganic composite filler, colored light due to light interference can be clearly produced without using a dental curable composition, especially without using a dye substance or a pigment substance. It is possible to obtain a curable composition that can be used as a dental filling and restorative material that can be used as a dental filling and restorative material that can be used as a dental filling and restorative material that can be used as a dental filling and restorative material that can be used as a dental filling and restorative material that can be confirmed and has good color compatibility and can be used for restorations that are similar to natural teeth.

As described above, colored light due to interference exhibits good color tone compatibility with natural teeth when the following formulas (2) and (3) are satisfied.

nM _B1 <nF _B2 (2)
(In formula (2), nM _B1 represents the refractive index at 25°C of the organic resin matrix (B1) constituting the organic-inorganic composite filler, and nF _B2 represents the refractive index at 25°C of the spherical inorganic filler (B2). .)

nP<nF _B2 (3)
(In formula (3), nP represents the refractive index at 25°C of the polymer of the polymerizable monomer component (A), and nF _B2 represents the refractive index of the spherical inorganic filler (B2) constituting the organic-inorganic composite filler. Represents the refractive index at °C.)

That is, the refractive index nF of the spherical inorganic filler ( _B2 ) is the refractive index nP of the polymer of the polymerizable monomer component (A) and the refractive index nM of the organic resin matrix (B1) constituting the organic-inorganic composite filler. It is important to be in a state higher than _B1 . The refractive index nF of the spherical inorganic filler (B2) The refractive index difference between _B2 and the refractive index nP of the polymer of the polymerizable monomer component (A) and the refractive index nF of the spherical inorganic filler (B2) _B2 and the organic resin matrix ( The difference between B1) and the refractive index nM _B1 is preferably 0.001 or more, more preferably 0.002 or more, and most preferably 0.005 or more.

Furthermore, when the contrast ratio (Yb/Yw) of the cured product of the curable composition of the present invention is in the range of 0.10 to 0.50 described above, colored light due to interference is clearly expressed and color tone is matched. The refractive index difference between the refractive index nF of the spherical inorganic filler ( _B2 ) and the refractive index nP of the polymer of the polymerizable monomer component (A) and the refractive index of the spherical inorganic filler (B2) The refractive index difference between nF _B2 and the refractive index nM _B1 of the organic resin matrix (B1) is preferably 0.1 or less, more preferably 0.05 or less, so as not to impair transparency as much as possible.

The content of the spherical inorganic filler (B2) in the organic-inorganic composite filler is preferably 30% by mass or more and 95% by mass or less. When the content in the organic-inorganic composite filler is 30% by mass or more, the cured product of the curable composition will exhibit good colored light, and the mechanical strength can also be sufficiently increased. Further, it is operationally difficult to incorporate the spherical inorganic filler (B2) in an amount exceeding 95% by mass in the organic-inorganic composite filler, and it becomes difficult to obtain a homogeneous filler. A more suitable content of the spherical inorganic filler (B2) in the organic-inorganic composite filler is 40 to 90% by mass.

Similar to the spherical inorganic filler (B) used in powder form, the refractive index of the silica/titanium group element oxide complex oxide, whose refractive index can be easily adjusted, depends on the silica content. It will range from about 1.45 to 1.58 accordingly. That is, when using a silica/titanium group element oxide-based composite oxide as the spherical inorganic filler (B2), the refractive index of the polymerizable monomer component (A) is within the above range (range of 1.38 to 1.55). ), the refractive index nP of the polymer obtained from the polymerizable monomer component (A) can be set within the range of approximately 1.40 to 1.57. The spherical inorganic filler (B2) can be easily selected so as to satisfy 3)). That is, a silica/titanium group element oxide complex oxide containing an appropriate amount of silica (for example, silica/titania or silica/zirconia) may be used.

In the organic-inorganic composite filler, the organic resin matrix (B1) is a homopolymer obtained using the same polymerizable monomer as described above as the polymerizable monomer component (A) or a copolymer of multiple types. Merger can be adopted without any restrictions. As mentioned above, when using a silica/titanium group element oxide complex oxide whose refractive index can be easily adjusted as the spherical inorganic filler (B2), the refractive index is 1.45 depending on the silica content. Therefore, by setting the refractive index nM _B1 of the organic resin matrix (B1) in the range of approximately 1.40 to 1.57, the above-mentioned condition (formula (2)) can be satisfied. can be satisfied.

The organic resin matrix (B1) may be the same as or different from the polymer obtained from the polymerizable monomer component (A), but the refractive index nM of the organic resin matrix (B1) _B1 and the polymerizable monomer component The difference in refractive index from the refractive index nP of the polymer (A) is preferably 0.005 or less from the viewpoint of transparency of the resulting curable composition. When the refractive index difference is greater than 0.005, the material becomes opaque and colored light due to interference becomes weak. Furthermore, the refractive index difference is more preferably in the range of 0.001 to 0.005 from the viewpoint that the refractive index difference can impart light diffusivity and improve the color compatibility between the curable composition and the tooth.

In the present invention, the organic-inorganic composite filler is prepared by mixing predetermined amounts of each component of the spherical inorganic filler (B2), a polymerizable monomer, and a polymerization initiator, and polymerizing the mixture by heating or light irradiation. Inorganic agglomerated particles formed by agglomerating spherical inorganic filler (B2) as described in the general manufacturing method of organic-inorganic composite filler and the pamphlets of International Publication No. 2011/115007 and International Publication No. 2013/039169, which are pulverized, After immersing in a polymerizable monomer solvent containing a polymerizable monomer, a polymerization initiator, and an organic solvent, the organic solvent is removed, and the polymerizable monomer is polymerized and cured by heating or light irradiation. Inorganic aggregated particles in which primary particles are aggregated have an organic resin phase that covers the surface of each inorganic primary particle and binds each inorganic primary particle to each other, and aggregates between the organic resin phases that cover the surface of each inorganic primary particle. It may be manufactured according to a method for manufacturing an organic-inorganic composite filler in which gaps are formed. As the polymerization initiator, any known polymerization initiator can be used without any particular restriction, but it is preferable to use a thermal polymerization initiator because it can obtain a cured product with a lower degree of yellowness. It is more preferable to use a compound having no group ring.

In the present invention, the average particle diameter of the organic-inorganic composite filler is not particularly limited, but it improves the mechanical strength of the cured product of the dental curable composition and the operability of the uncured paste of the composition. From this point of view, the thickness is preferably 2 to 100 μm, more preferably 4 to 50 μm, and particularly preferably 5 to 30 μm. The shape is not particularly limited, and the spherical inorganic filler (B2), polymerizable monomer, and polymerization initiator are mixed in predetermined amounts and polymerized by heating or light irradiation. Examples include amorphous ones obtained by crushing and pulverizing, and spherical or approximately spherical ones manufactured according to the method described in International Publication No. 2011/115007 pamphlet and International Publication No. 2013/039169 pamphlet. .

The organic-inorganic composite filler may contain known additives within a range that does not impede its effects. Specific examples of additives include pigments, polymerization inhibitors, fluorescent brighteners, and the like. Each of these additives can be used in an amount of usually 0.0001 to 5 parts by weight per 100 parts by weight of the organic-inorganic composite filler.

Further, the organic-inorganic composite filler may be washed or surface-treated with a silane coupling agent or the like.

The blending amount of the organic-inorganic composite filler in the present invention is 50 to 1000 parts by mass based on 100 parts by mass of the polymerizable monomer component (A) when the organic-inorganic composite filler is only used in the dental curable composition. In order to improve the operability of the product paste and the mechanical strength of the cured product, the organic-inorganic composite filler may be blended in an amount of 70 to 600 parts by mass, more preferably 100 to 400 parts by mass. Further, as described above, the blending amount of the spherical inorganic filler (B2) in the organic-inorganic composite filler is preferably 30% by mass or more and 95% by mass or less, and more preferably 40 to 90% by mass. Therefore, the amount of the spherical inorganic filler that affects the development of colored light due to interference is 10% by mass ((50/150) x 30%) or more and 86.4% by mass ((1000/1100%) in the curable composition. )×95%) or less. When using together the spherical inorganic filler (B) used in powder form and the organic-inorganic composite filler, coloring due to interference can be avoided by blending the inorganic filler component in an amount of 10% to 86% by mass in the curable composition. Light will appear better. The blending amount of the inorganic filler component is more preferably 15% by mass to 86% by mass, still more preferably 20% by mass to 86% by mass. Furthermore, in order to improve the operability of the paste of the curable composition and the mechanical strength of the cured product, the blending ratio (mass ratio) of the spherical inorganic filler (B) and the organic-inorganic composite filler should be adjusted from 90:10 to 10:1. The ratio is preferably 90, more preferably 80:20 to 20:80, particularly preferably 70:30 to 30:70.

<Polymerization initiator (C)>
The polymerization initiator (C) comprises three components: a photosensitizing compound (C1), a tertiary amine compound (C2), and a photoacid generator (C3). These components will be explained below.

(Photosensitizing compound (C1))
The photosensitizing compound (C1) in the present invention is a compound that has a maximum absorption wavelength in the range of 350 nm to 700 nm and has a function of generating active species effective for polymerization. Activated species typically result from energy or electron transfer between the light-absorbing and excited photosensitizing compound and the polymerizable monomer or other compound.

As the photosensitizing compound (C1), any known photosensitizing compound can be used without any restriction. Photosensitizing compounds particularly preferably used in the present invention 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; , 4'-dimethylbenzophenone, benzophenones such as 4-methacryloxybenzophenone, α-diketones such as diacetyl, 2,3-pentadionebenzyl, camphorquinone, 9,10-phenanthraquinone, 9,10-anthraquinone, etc. , thioxanthone compounds such as 2,4-diethoxythioxanthone, 2-chlorothioxanthone, 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(2,4-dichlorobenzoyl)-1-naphthylphosphine oxide, , 6-trimethylbenzoyl)-phenylphosphine oxide and the like.

Among the above, α-diketone compounds such as camphorquinone, 9,10-phenanthrenequinone, benzyl, diacetyl, acetylbenzoyl, 2,3-pentadione, 2,3-octadione, 4,4'-dimethoxybenzyl, acenaphthenequinone, etc. is more preferable.

The amount of the photosensitizing compound (C1) used is not particularly limited, but is usually 0.01 to 10 parts by weight, and 0.03 parts by weight based on 100 parts by weight of the polymerizable monomer (A). It is preferably from 0.05 to 5 parts by weight, and more preferably from 0.05 to 2 parts by weight.

(Tertiary amine compound (C2))
As the tertiary amine compound (C2), any known tertiary amine compound can be used without any restriction. Aromatic tertiary amine compounds are preferred from the viewpoint of odor and the like. Aromatic tertiary amine compounds preferably used in the present invention include N,N-dimethylaniline, N,N-dibenzylaniline, N,N-dimethyl-p-toluidine, N,N-diethyl-p -toluidine, methyl p-(N,N-dimethyl)aminobenzoate, ethyl p-(N,N-dimethyl)aminobenzoate, amyl p-(N,N-dimethyl)aminobenzoate, and the like.

Further, as the tertiary amine compound (C2), an aliphatic tertiary amine compound may be used. Specific examples include triethanolamine, N-methyldiethanolamine, triethylamine, tributylamine, N,N-dimethylaminoethyl methacrylate, and N,N-diethylaminoethyl methacrylate.

The amount of the tertiary amine compound (C2) used is not particularly limited, but is usually 10 parts by mass to 1000 parts by mass, and 50 parts by mass to 500 parts by mass, based on 100 parts by mass of the photosensitizing compound (C1). parts by weight, preferably from 75 parts by weight to 300 parts by weight.

(Photoacid generator (C3))
As the photoacid generator (C3), any known photoacid generator can be used without any restriction. Examples of the photoacid generator suitably used in the present invention include aryliodonium salt compounds, sulfonium salt compounds, sulfonic acid ester compounds, s-triazine compounds having a halomethyl group as a substituent, and pyridinium salt compounds. Among them, aryliodonium salt compounds or s-triazine compounds having a halomethyl group as a substituent are particularly preferred.

For example, aryliodonium salt-based compounds include diphenyliodonium, bis(p-chlorophenyl)iodonium, ditolyliodonium, bis(p-methoxyphenyl)iodonium, bis(p-tert-butylphenyl)iodonium, p-isopropylphenyl-p - Cations such as methylphenyliodonium, bis(m-nitrophenyl)iodonium, p-tert-butylphenylphenyliodonium, p-methoxyphenylphenyliodonium, p-octyloxyphenylphenyliodonium, p-phenoxyphenylphenyliodonium, and nitrates. , acetate, chloroacetate, carboxylate, phenolate, and other anions.

Further, as the s-triazine compound having a halomethyl group as a substituent, any known compound can be used without any restriction as long as it is an s-triazine compound having at least one trichloromethyl group or tribromomethyl group. For example, it is represented by the following general formula (1).

In general formula (1), R ³ and R ⁴ are an organic group, an alkyl group, or an alkoxy group having an unsaturated bond that can be conjugated with a triazine ring, and X is a halogen atom. In the general formula (1), the halogen atom represented by X may be chlorine, bromine, or iodine, but chlorine is generally used. Therefore, the substituent (CX ₃ ) bonded to the triazine ring is generally a trichloromethyl group.

R ³ and R ⁴ may be any of an organic group, an alkyl group, and an alkoxy group having an unsaturated bond that can be conjugated with a triazine ring, but it is preferable that at least one of R ³ and R ⁴ is a halogen-substituted alkyl group. It is easier to obtain better polymerization activity, and the polymerization activity is particularly good when both are halogen-substituted alkyl groups.

The organic group bonded to the triazine ring via an unsaturated bond capable of conjugation may be any known organic group, but is preferably an organic group having 2 to 30 carbon atoms, more preferably 2 to 14 carbon atoms. Specific examples of such organic groups include phenyl group, methoxyphenyl group, p-methylthiophenyl group, p-chlorophenyl group, 4-biphenylyl group, naphthyl group, 4-methoxy-1-naphthyl group, etc. Examples thereof include an aryl group having 6 to 14 carbon atoms; an alkenyl group having 2 to 14 carbon atoms such as a vinyl group, a 2-phenylethenyl group, and a 2-(substituted phenyl)ethenyl group; and the like. The substituents of the above-mentioned substituted phenyl group include alkyl groups having 1 to 6 carbon atoms such as methyl, ethyl, and propyl groups; alkoxy groups having 1 to 6 carbon atoms such as methoxy, ethoxy, and propoxy groups; ; C1-C6 alkylthio groups such as methylthio group, ethylthio group, propylthio group; phenyl group; halogen atom; and the like. Furthermore, in R ³ and R ⁴ , the alkyl group and the alkoxy group may have a substituent, and such an alkyl group preferably has 1 to 10 carbon atoms, such as a methyl group or an ethyl group. , n-propyl group, i-propyl group, n-butyl group, n-hexyl group, etc.; unsubstituted alkyl groups such as trichloromethyl group, tribromomethyl group, α, α, β-trichloroethyl group, etc. Examples include alkyl groups. Further, the alkoxy group preferably has 1 to 10 carbon atoms, such as unsubstituted alkoxy groups such as methoxy group, ethoxy group, butoxy group; 2-{N,N-bis(2-hydroxyethyl)amino} Amino such as ethoxy group, 2-{N-hydroxyethyl-N-ethylamino}ethoxy group, 2-{N-hydroxyethyl-N-methylamino}ethoxy group, 2-{N,N-diallylamino}ethoxy group Examples include an alkoxy group substituted with a group; and the like.

Specific examples of the trihalomethyl group-substituted s-triazine compound represented by the above general formula (3) include 2,4,6-tris(trichloromethyl)-s-triazine, 2,4,6- Tris(tribromomethyl)-s-triazine, 2-methyl-4,6-bis(trichloromethyl)-s-triazine, 2-methyl-4,6-bis(tribromomethyl)-s-triazine, 2- Phenyl-4,6-bis(trichloromethyl)-s-triazine, 2-(p-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(p-methylthiophenyl)-4, 6-bis(trichloromethyl)-s-triazine, 2-(p-chlorophenyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(2,4-dichlorophenyl)-4,6-bis( trichloromethyl)-s-triazine, 2-(p-bromophenyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(p-tolyl)-4,6-bis(trichloromethyl)-s -triazine, 2-n-propyl-4,6-bis(trichloromethyl)-s-triazine, 2-(α,α,β-trichloroethyl)-4,6-bis(trichloromethyl)-s-triazine, 2-styryl-4,6-bis(trichloromethyl)-s-triazine, 2-[2-(p-methoxyphenyl)ethenyl]-4,6-bis(trichloromethyl)-s-triazine, 2-[2 -(o-methoxyphenyl)ethenyl]-4,6-bis(trichloromethyl)-s-triazine, 2-[2-(p-butoxyphenyl)ethenyl]-4,6-bis(trichloromethyl)-s- Triazine, 2-[2-(3,4-dimethoxyphenyl)ethenyl]-4,6-bis(trichloromethyl)-s-triazine, 2-[2-(3,4,5-trimethoxyphenyl)ethenyl] -4,6-bis(trichloromethyl)-s-triazine, 2-(1-naphthyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-biphenylyl)-4,6-bis (Trichloromethyl)-s-triazine, 2-[2-{N,N-bis(2-hydroxyethyl)amino}ethoxy]-4,6-bis(trichloromethyl)-s-triazine, 2-[2- {N-hydroxyethyl-N-ethylamino}ethoxy]-4,6-bis(trichloromethyl)-s-triazine, 2-[2-{N-hydroxyethyl-N-methylamino}ethoxy]-4,6 -bis(trichloromethyl)-s-triazine, 2-[2-{N,N-diallylamino}ethoxy]-4,6-bis(trichloromethyl)-s-triazine, and the like.

The amount of the photoacid generator (C3) used is not particularly limited, but it is usually 10 parts by mass to 2000 parts by mass, and 20 parts by mass to 1000 parts by mass, based on 100 parts by mass of the photosensitizing compound (C1). The amount is preferably from 50 parts by mass to 800 parts by mass.

<Fumed silica (D)>
The dental curable composition of the present invention contains fumed silica (D). Since it contains fumed silica (D), the change in contrast ratio is small immediately after curing and after curing, and the dental curable composition of the present invention can be used in large-scale restoration treatments such as deep cavities. It becomes possible to perform restorations that continue to harmonize with the teeth.

In the present invention, it is important that the fumed silica (D) has an average primary particle diameter of less than 100 nm. When the average primary particle diameter of fumed silica is 100 nm or more, it is not preferable because the regular structure of the spherical inorganic filler (B) is disturbed and the interference light is attenuated. Therefore, from the viewpoint of controlling contrast ratio changes without affecting interference light, fumed silica with an average primary particle diameter of less than 100 nm is preferable, more preferably 3 nm or more and 50 nm or less, and still more preferably fumed silica with an average primary particle size of 5 nm or more and 30 nm or less. .

In the present invention, the fumed silica (D) may be surface-treated with a known silane coupling agent. By surface treatment, the fumed silica (D) has excellent dispersibility in the polymerizable monomer component (A). Typical silane coupling agents include organosilicon compounds such as γ-methacryloyloxyalkyltrimethoxysilane and hexamethyldisilazane. There is no particular limit to the amount of these silane coupling agents used to treat the surface, but a preferred range is from 5 to 400 parts by mass per 100 parts by mass of fumed silica (D).

The amount of fumed silica (D) to be blended is not particularly limited, but the preferred range is 2 to 40 parts by weight based on 100 parts by weight of the polymerizable monomer component (A). By dispersing 2 parts by weight or more of fumed silica (D) in the polymerizable monomer component (A), it becomes possible to further reduce the change in contrast ratio between immediately after curing and after post-curing of the composition. . Further, when the amount is 40 parts by weight or less, a dental curable composition with excellent operability can be obtained. Considering the above, the amount of fumed silica (D) to be blended is more preferably 4 to 30 parts by weight, and even more preferably 6 to 20 parts by weight.

<Other additives>
In addition to the above-mentioned components (A) to (D), other known additives may be added to the curable composition of the present invention as long as the effects thereof are not impaired. Specific examples include polymerization inhibitors and ultraviolet absorbers.

As described above, in the present invention, a single paste (curable composition) can perform a restoration with good color compatibility with natural teeth without using a coloring substance such as a pigment. Therefore, it is preferable that pigments that may change color over time are not added. However, in the present invention, the blending of pigments itself is not denied, and pigments may be blended to the extent that they do not interfere with colored light due to interference from the spherical filler. Specifically, the pigment may be blended in an amount of about 0.0005 to 0.5 parts by mass, preferably about 0.001 to 0.3 parts by mass, per 100 parts by mass of the polymerizable monomer. .

The dental curable composition of the present invention can be used as a flowable type composite resin. In order to provide suitable operability as a flowable type composite resin and a bulk fill type composite resin, when measuring the shear rate versus shear stress of the composition using a rotational viscometer, it is necessary to It is preferable that the loop internal area is 10 Pa/s or more and 5000 Pa/s or less. The loop curve (X) is obtained by scanning the shear rate in the range of 0.01 revolutions per second to 5 revolutions per second.

When the loop internal area of the loop curve (X) of the dental curable composition of the present invention is 10 Pa/s or more and 5000 Pa/s or less, the paste becomes easy to fill into a deep cavity and easy to build up. preferable.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.

The methods for measuring various physical properties in the present invention are as follows.

(1) Average primary particle diameter of spherical particles (B) and spherical inorganic filler (B2) A photograph of the powder was taken with a scanning electron microscope (manufactured by Philips, "XL-30S") at a magnification of 5000 to 100000 times, Using image analysis software ("IP-1000PC", product name; manufactured by Asahi Kasei Engineering Co., Ltd.), the photographed images are processed and the number of particles (30 or more) observed within the unit field of view of the photograph and the primary The particle diameter (maximum diameter) was measured, and the number average primary particle diameter was calculated using the following formula based on the measured value.

(2) Existence ratio of average particle diameter particles of spherical particles (B) and spherical inorganic filler (B2) In the present invention, the ratio of particles existing in a range of 5% before and after the average primary particle diameter of spherical particles (B) (%) indicates particles having a primary particle diameter (maximum diameter) outside the particle diameter range of 5% before and after the average primary particle diameter determined above among all particles (30 or more) within the unit field of view of the above photograph. The number of particles is measured and subtracted from the number of all particles to determine the number of particles within a particle size range of 5% before and after the average primary particle size within the unit field of view of the above photograph, and the following formula:
Percentage (%) of particles within a range of 5% before and after the average primary particle diameter of the spherical filler (B) = [(Within a particle size range of 5% before and after the average primary particle diameter within the unit field of view of the scanning electron micrograph (number of particles) / (total number of particles within a unit field of view of a scanning electron micrograph)] x 100
Calculated according to

(3) Average uniformity of spherical particles (B) and spherical inorganic filler (B2) A photograph of the powder is taken with a scanning electron microscope, and the number of particles observed within the unit field of view of the photograph (n: 30 (above), the maximum diameter of the particle was determined as the major axis (Li), and the diameter in the direction perpendicular to the major axis was determined as the minor axis (Bi), and the calculation was performed using the following formula.

(4) Average particle diameter (particle size) of organic-inorganic composite filler
0.1 g of organic-inorganic composite filler was dispersed in 10 ml of ethanol, and ultrasonic waves were irradiated for 20 minutes. Using a particle size distribution analyzer using a laser diffraction-scattering method ("LS230", manufactured by Beckman Coulter), the optical model "Fraunhofer" was applied to determine the median diameter of volume statistics.

(5) Measurement of refractive index <Refractive index of polymerizable monomer component (A)>
The refractive index of the polymerizable monomer (or mixture of polymerizable monomers) used was measured in a thermostatic chamber at 25° C. using an Abbe refractometer (manufactured by Atago).

<Refractive index (nP) of polymer of polymerizable monomer component (A)>
The refractive index of the polymer of the polymerizable monomer (or mixture of polymerizable monomers) used was determined using an Abbe refractometer (manufactured by Atago). ) in a thermostatic chamber at 25°C.

That is, a homogeneous polymerizable monomer (or a mixture of polymerizable monomers) containing 0.2% by mass of CQ, 0.3% by mass of DMBE, and 0.15% by mass of HQME was placed in a 7 mmφ x 0.5 mm It was placed in a mold having through holes, and polyester films were pressed on both sides. After that, it was cured by irradiating light for 30 seconds using a halogen-type dental light irradiator (Demetron LC, manufactured by Cyblon) with a light intensity of 500 mW/ ^cm2 , and then removed from the mold to form a polymer of polymerizable monomers. Created. When setting the polymer in the Abbe refractometer (manufactured by Atago), in order to bring the polymer into close contact with the measurement surface, add a solvent (bromonaphthalene) that does not dissolve the sample and has a higher refractive index than the sample. The sample was added dropwise and measured.

<Refractive index nM _b1 of organic resin matrix (B1)>
The refractive index of the organic resin matrix was measured using an Abbe refractometer (manufactured by Atago Co., Ltd.) in a thermostatic chamber at 25° C. for a polymer polymerized under substantially the same polymerization conditions as those used for producing the organic-inorganic composite filler.

That is, a homogeneous polymerizable monomer (or mixture of polymerizable monomers) mixed with 0.5% by mass of AIBN was placed in a mold having a through hole of 7 mmφ x 0.5 mm, and a polyester film was placed on both sides. Pressed. Thereafter, after polymerization and curing by heating under nitrogen pressure for one hour, the product was removed from the mold to produce a polymer (organic resin matrix) of the polymerizable monomer. When setting the polymer in the Abbe refractometer (manufactured by Atago), in order to bring the polymer into close contact with the measurement surface, add a solvent (bromonaphthalene) that does not dissolve the sample and has a higher refractive index than the sample. The sample was added dropwise and measured.

<Refractive index of spherical particles (B), spherical inorganic filler (B2), fumed silica (D)>
The refractive index of the spherical particles, spherical inorganic filler, and fumed silica used was measured by an immersion method using an Abbe refractometer (manufactured by Atago).

That is, in a thermostatic chamber at 25° C., 1 g of spherical inorganic filler or inorganic particles or surface-treated material thereof is dispersed in 50 ml of anhydrous toluene in a 100 ml sample bottle. While stirring this dispersion with a stirrer, 1-bromotoluene was added dropwise little by little, and the refractive index of the dispersion was measured when the dispersion became most transparent.The obtained value was taken as the refractive index of the inorganic filler. did.

(6) Measurement of fluidity of composition <Loop internal area>
The dental curable composition pastes prepared in Examples and Comparative Examples were measured using Modular Compact Rheometer MCR302 (manufactured by Anton Paar) according to the following procedure.

After installing the aluminum disposable sample stand in the main body of the apparatus, adjust the temperature of the sample stand to 23°C. After the temperature of the sample stand stabilizes, 0.6 g of the paste of the composition is placed on the sample stand, and the paste is pressed into contact with a parallel plate (φ20 mm) connected to the main body of the apparatus so that the thickness of the paste becomes 1 mm. After standing in this state for 2 minutes, the shear rate was scanned between 0.01 revolutions per second and 5 revolutions per second using the measurement software RheoCompass (manufactured by Anton Paar), and the shear speed and shear stress corresponding to it were recorded. (This is the forward measurement process.) After the measurement process is completed, the shear rate is continuously scanned from 5 rotations per second to 0.01 rotations per second, and the shear rate and shear stress corresponding to the shear rate are recorded (this is the return measurement process). When the shear rate and shear stress obtained in this way are plotted on an XY graph of shear rate versus shear stress, the curve of the forward and return measurement process becomes a hysteresis curve. The area surrounded by this hysteresis curve was defined as the loop internal area (Pa/s), and was evaluated as the fluidity of the composition.

<Extrusion evaluation>
Terumo syringe SS-01ES was filled with 1 mL of the dental curable composition paste prepared in Examples and Comparative Examples, and a Tokuyama dispensing tip (manufactured by Tokuyama Dental Co., Ltd.) was attached, and the paste was extruded. At that time, the evaluation criteria for ease of extrusion are indicated by the numbers below.
1: It is possible to extrude without difficulty. Good discharge properties.
2: It is possible to extrude.
3: This is the lower limit that can be extruded in consideration of practical use.
4: Slight resistance felt. Slightly difficult to push out.
5: Difficult to extrude.

<Flow properties>
0.1 g of the dental curable composition paste prepared in Examples and Comparative Examples is taken into a hemispherical shape with a diameter of 5 mm. This paste is left to stand in a 37° C. incubator for 2 minutes, and the diameter of the spread paste is measured.

(7) Visual evaluation of colored light The pastes of the curable compositions prepared in the Examples and Comparative Examples were put into a mold having a 7 mmφ x 1 mm through hole, and both sides were pressed with polyester films. After curing by irradiating both sides with visible light irradiator (manufactured by Tokuyama, Power Light) for 30 seconds each, remove from the mold, place on the adhesive side of black tape (carbon tape) about 10 mm square, and visually color it. I checked the color of the light.

(8) Wavelength of colored light The pastes of the curable compositions prepared in the Examples and Comparative Examples were put into a mold having a through hole of 7 mmφ×1 mm, and a polyester film was pressed on both sides. After curing by irradiating both sides with light for 30 seconds each using a visible light irradiator (manufactured by Tokuyama, Power Light), the 1 mm thick cured product was removed from the mold, and a color difference meter (manufactured by Tokyo Denshoku, "TC-1800MKII") was used. The spectral reflectance was measured using a black background and a white background, and the maximum point of the reflectance on the black background was taken as the wavelength of the colored light.

(9) Evaluation of contrast ratio (Yb/Yw) and contrast ratio change (ΔYb/Yw) of curable composition A through-hole of 7 mmφ x 1 mm was inserted into the paste of the curable composition prepared in the Examples and Comparative Examples. It was placed in a mold with polyester film pressed onto both sides. After curing by irradiating both sides with light for 30 seconds each using a visible light irradiator (manufactured by Tokuyama, Power Light), the 1 mm thick cured product was removed from the mold, and a color difference meter (manufactured by Tokyo Denshoku, "TC-1800MKII") was used. The tristimulus Y value (background color black and white) of the cured product was measured using the following. The following formula,
The contrast ratio (Yb/Yw) was calculated based on the contrast ratio (Yb/Yw) = Y value when the background color is black/Y value when the background color is white, and this was taken as the contrast ratio of the cured product immediately after curing. .
After measuring the contrast ratio of the cured product immediately after curing by the above operation, the cured product was immersed in 5 mL of distilled water in a brown glass bottle and left standing in a 37° C. incubator for 24 hours. After 24 hours, the cured product was taken out of the water, the water was removed, and the tristimulus Y value (background color black and white) of the cured product was measured in the same manner as above, and the contrast ratio (Yb/Yw ) was calculated. This contrast ratio was taken as the contrast ratio after 24 hours in water at 37°C (after post-curing).

From the obtained contrast ratio immediately after curing and the contrast ratio after 24 hours of immersion in 37°C water, the change in contrast ratio (ΔYb/Yw) of a 1 mm thick cured product after 24 hours of immersion in 37°C water from immediately after curing can be calculated using the following formula. I asked for it.

ΔYb/Yw = Contrast ratio immediately after curing - Contrast ratio after immersion in water at 37°C for 24 hours

(10) Evaluation of color tone compatibility using a colorimeter Using a hard resin tooth that reproduces a class I cavity (diameter 4 mm, depth 4 mm) in the center of the occlusal surface at number 6 on the lower right, a hardenable composition is applied to the defect area. It was filled, hardened, and polished, and the color compatibility was evaluated using a two-dimensional colorimeter (manufactured by Papalabo, "RC-500") (hereinafter referred to as a restorative resin tooth). In addition, the hard resin teeth are in the A series (reddish brown) category in the shade guide (VITA Classical, manufactured by VITA), and include high chroma hard resin teeth (equivalent to A4) and low chroma hard resin teeth. High chroma hard resin teeth (B4 equivalent) and low chroma hard resin teeth in the B series (red-yellow) category of teeth (equivalent to A1) and shade guides (“VITA Classical”, manufactured by VITA). (equivalent to B1) was used.

The hard resin tooth is set in a two-dimensional colorimeter, the hard resin tooth is photographed, and the photographed image is processed using image analysis software ("RC Series Image Viewer", manufactured by Papalabo) to repair the hard resin tooth. The color difference between the colorimetric values (ΔE ^* in CIELab) between the repaired area and the non-repaired area was determined, and the color tone compatibility was evaluated.

ΔE ^* = {(ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² } ^1/2
ΔL ^* = L1 ^* - L2 ^*
Δa ^* = a1 ^* - a2 ^*
Δb ^* = b1 ^* - b2 ^*
In addition, L1 ^* : Lightness index of the restoration part of hard resin tooth, a1 ^* , b1 ^* : Color quality index of the restoration part of hard resin tooth, L2 ^* : Lightness index of the restoration part of hard resin tooth, a2 ^* , b2 ^* : Color quality index of the restoration part of hard resin tooth, ΔE ^* : Amount of color change.

After evaluating the color compatibility of the restored resin tooth immediately after curing by the above operation, the restored resin tooth was stored in ion-exchanged water at 37° C. for 24 hours. The color compatibility of the restored resin teeth after storage was also evaluated in the same manner.

(11) Visual evaluation of color tone compatibility Using a hard resin tooth that reproduces a class I cavity (diameter 4 mm, depth 4 mm) in the center of the occlusal surface in the lower right No. 6, the defective part is filled with a curable composition. After hardening and polishing, color tone compatibility was visually confirmed and evaluated on a five-point scale. In addition, the hard resin teeth are in the A series (reddish brown) category in the shade guide (VITA Classical, manufactured by VITA), and include high chroma hard resin teeth (equivalent to A4) and low chroma hard resin teeth. High chroma hard resin teeth (B4 equivalent) and low chroma hard resin teeth (equivalent to B4) are in the B series (red-yellow) category of teeth (equivalent to A1) and shade guides (“VITA Classic”, manufactured by VITA). A tooth (corresponding to B1) was used.
5: The color tone of the restoration is indistinguishable from that of hard resin teeth.
4: The color tone of the restoration matches well with the hard resin tooth.
3: The color tone of the restoration is similar to that of hard resin teeth.
2: The color tone of the restoration is similar to that of the hard resin tooth, but the compatibility is not good.
1: The color tone of the restoration does not match the hard resin tooth.

After evaluating the color compatibility of the restored resin tooth immediately after curing by the above operation, the restored resin tooth was stored in ion-exchanged water at 37° C. for 24 hours. The color compatibility of the restored resin teeth after storage was also visually evaluated.

The polymerizable monomers, polymerization initiators, inorganic particles, etc. used in Examples and Comparative Examples are as follows.

[Polymerizable monomer]
・1,6-bis(methacrylethyloxycarbonylamino)trimethylhexane (hereinafter abbreviated as "UDMA")
・Triethylene glycol dimethacrylate (hereinafter abbreviated as "3G")
・2,2-bis[(3-methacryloyloxy-2-hydroxypropyloxy)phenyl]propane (hereinafter abbreviated as "bis-GMA")
[Polymerization initiator]
- Camphorquinone (hereinafter abbreviated as "CQ").
- Ethyl p-(N,N-dimethyl)aminobenzoate (hereinafter abbreviated as "DMBE").
- Diphenyliodonium-2-carboxylate monohydrate (hereinafter abbreviated as "DPIC").
・Azobisisobutyronitrile (hereinafter abbreviated as "AIBN")
[Polymerization inhibitor]
・Hydroquinone monomethyl ether (hereinafter abbreviated as "HQME")
[Fumed silica]
・Rheolo Seal QS-102 (average primary particle diameter 12 nm, manufactured by Tokuyama Co., Ltd.)
[Manufacture of polymerizable monomer component]
Polymerizable monomers as shown in Table 1 were mixed to prepare matrices M1 and M2.

[Manufacture of spherical particles and spherical inorganic filler]
The spherical particles and the spherical inorganic filler can be prepared by using methods described in JP-A-58-110414, JP-A-58-156524, etc., using hydrolyzable organosilicon compounds (such as tetraethyl silicate). A mixed solution containing organic titanium group metal compounds (tetrabutyl zirconate, tetrabutyl titanate, etc.) is placed in an ammoniacal alcohol (e.g., methanol, ethanol, isopropyl alcohol, isobutyl alcohol, etc.) solution containing ammonia water. It was prepared using a so-called sol-gel method, in which a reaction product is precipitated by adding and hydrolyzing the product, followed by drying, pulverizing if necessary, and baking.

The amorphous inorganic filler can be prepared by dissolving an alkoxysilane compound in an organic solvent and adding water thereto for partial hydrolysis using the method described in JP-A-2-132102, JP-A-3-197311, etc. After that, alkoxides of other metals and alkali metal compounds to be further compounded are added and hydrolyzed to produce a gel-like material, and then the gel-like material is dried, then crushed as necessary, and fired. Prepared using

Table 2 shows the spherical inorganic fillers and amorphous fillers used in the Examples and Comparative Examples.

[Manufacture of amorphous organic-inorganic composite filler]
A thermal polymerization initiator (AIBN) is dissolved in advance in a mass ratio of 0.5% in the matrix shown in Table 1, and predetermined amounts (Table 3) of spherical inorganic fillers and amorphous inorganic fillers shown in Table 2 are added and mixed. It was then made into a paste in a mortar. This was polymerized and cured by heating at 95° C. for one hour under nitrogen pressure. This cured product was ground using a vibrating ball mill, and further surface-treated by refluxing in ethanol at 90°C for 5 hours with 0.02% by mass of γ-methacryloyloxypropyltrimethoxysilane, as shown in Table 3 below. Amorphous organic-inorganic composite fillers CF1 and CF2 shown in the figure were obtained.

Examples 1 to 5
Under red light, 0.3% by weight of CQ, 1.0% by weight of DMBE, 1.0% by weight of DPIC, and 0.15% by weight of HQME were added to matrix M1 and mixed to form a uniform mixture. A polymerizable monomer composition was prepared. Next, each filler shown in Tables 2 and 3 was weighed out in a mortar, and the above polymerizable monomer composition was gradually added under red light, and thoroughly kneaded to form a uniform curable paste. . Furthermore, this paste was degassed under reduced pressure to remove air bubbles to produce a dental curable composition. The physical properties of the obtained dental curable composition were evaluated based on the methods described above. The composition and results are shown in Tables 4, 5, and 6.

Comparative Examples 1 to 3 and Comparative Example 5
Under red light, 0.3% by weight of CQ, 1.0% by weight of DMBE, 1.0% by weight of DPIC, and 0.15% by weight of HQME are added and mixed to matrix M1 or M2, A uniform polymerizable monomer composition was prepared. Next, each filler shown in Tables 2 and 3 was measured into a mortar, and the above polymerizable monomer composition was gradually added under red light, and thoroughly kneaded to form a uniform curable paste. . Furthermore, this paste was degassed under reduced pressure to remove air bubbles to produce a dental curable composition. The physical properties of the obtained dental curable composition were evaluated based on the methods described above. The composition and results are shown in Tables 4, 5, and 6.

Comparative example 4
Under red light, 0.3% by weight of CQ, 1.0% by weight of DMBE, and 0.15% by weight of HQME are added and mixed to matrix M1 or M2 to obtain a uniform polymerizable monomer composition. I prepared something. Next, each filler shown in Tables 2 and 3 was measured into a mortar, and the above polymerizable monomer composition was gradually added under red light, and thoroughly kneaded to form a uniform curable paste. . Furthermore, this paste was degassed under reduced pressure to remove air bubbles to produce a dental curable composition. The physical properties of the obtained dental curable composition were evaluated based on the methods described above. The composition and results are shown in Tables 4, 5, and 6.

As understood from the results of Examples 1 to 5, when the conditions specified in the present invention are satisfied, the cured dental curable composition exhibits colored light according to the filler particle size, and The contrast ratio change is small between immediately after curing and after 24 hours in 37°C water (after post-curing), so even when filling deep cavities, color tone compatibility is maintained both immediately after curing and after 24 hours in 37°C water (after post-curing). It can be seen that the results are good.

As can be understood from the results of Examples 1 and 2 and Comparative Example 1, if the particle size conditions of the spherical inorganic filler specified in the present invention are not met, the cured product of the dental curable composition will be hardened against a black background. It shows blue colored light, indicating that the color tone compatibility is poor.

Furthermore, as can be understood from the results of Examples 1 and 2 and Comparative Example 2, if the conditions for the spherical inorganic filler specified in the present invention are not met, the cured product of the dental curable composition will not appear on a black background. It shows no colored light, indicating poor color tone compatibility.

Furthermore, as understood from the results of Examples 1 and 2 and Comparative Example 3, if the relationship between the refractive index after polymerization of the filler and the polymerizable monomer specified in the present invention is not satisfied, dental hardening will occur. It can be seen that the color composition exhibits blue light against a black background, indicating poor color compatibility.

As can be understood from the results of Example 5 and Comparative Example 4, if the conditions for the polymerization initiator specified in the present invention are not met, the curing reaction will be slow, and the curing reaction will be slow, and both immediately after curing and after 24 hours in 37°C water (afterwards). It can be seen that the contrast ratio change becomes large (after curing), and the color tone compatibility immediately after curing is poor.

As can be understood from the results of Example 3 and Comparative Example 5, if fumed silica is not included, the contrast ratio changes immediately after curing and after 24 hours in 37°C water (after post-curing) are large; It can be seen that the color tone compatibility is poor.

Claims (4)

Contains a polymerizable monomer (A), an inorganic spherical filler (B) with an average particle diameter in the range of 230 to 1000 nm, a polymerization initiator (C), and fumed silica (D) with an average particle diameter of less than 100 nm. It consists of
The refractive index at 25° C. of the polymer obtained by polymerizing the polymerizable monomer (A): nP is 1.40 to 1.57,
The inorganic spherical filler (B) is a silica/titanium group element oxide composite oxide particle that has a refractive index nF of 1.45 to 1.58 at 25° C. and satisfies the relationship of the formula: nP<nF. and 90% or more of the individual particles constituting the inorganic spherical filler (B) exist within 5% of the average particle diameter,
The blending amount of the inorganic spherical filler (B) with respect to 100 parts by mass of the polymerizable monomer (A) is 50 parts by mass or more and 600 parts by mass or less,
The polymerization initiator (C) is a dental curable composition consisting of a photosensitizing compound (C1), a tertiary amine compound (C2), and a photoacid generator (C3),
A dental curable composition characterized in that a contrast ratio change of a 1 mm thick cured product immediately after curing and after being immersed in water at 37° C. for 24 hours is within 0.08. The dental curable composition according to claim 1, wherein the photoacid generator (C3) contains an aryliodonium salt or an s-triazine compound having a halomethyl group as a substituent. The dental curable composition according to claim 1 or 2, comprising 2 to 40 parts by mass of fumed silica (D) based on 100 parts by mass of the polymerizable monomer component (A). The dental curable composition according to any one of claims 1 to 3, wherein the loop internal area of a shear rate versus shear stress curve measured with a rotational viscometer is 10 Pa/s or more and 5000 Pa/s or less.