JP2020011917A - Dental curable composition - Google Patents

Abstract

To provide a dental curable composition that can suitably be used as a dental composite resin having high color tone compatibility even when used for restoring a class III cavity or a class IV cavity, without using a pigment substance or a dye substance.SOLUTION: The dental curable composition comprises: a polymerizable monomeric component (A); an inorganic spherical filler (B) having an average primary particle diameter in the range of 100 to 1000 nm and 90% or more of the total number of particles in the number-based particle size distribution in a range of 5% before and after the average primary particle diameter; and a polymerization initiator (D). The inorganic spherical filler (B) provides a curable composition with a hardening body developing a structural color by polymerizing the polymerizable monomeric component (A), the refractive index at 25°C of the inorganic spherical filler being larger than the refractive index at 25°C of the obtained polymer. An amorphous inorganic filler (C) having an average particle diameter of 100 to 1000 nm is further formulated to the curable composition, thereby giving a hardening body having appropriate opacity while maintaining the visibility of the structural color.SELECTED DRAWING: None

Description

  The present invention relates to a dental curable composition. Specifically, the present invention relates to a dental curable composition suitable for use as a dental filling and restorative material which is easy to use and excellent in aesthetics.

  Dental composite resin (hereinafter, also simply referred to as “CR”) is a type of material for restoring teeth damaged by caries or fractures, and is composed of polymerizable monomers, inorganic and inorganic materials. And / or a curable composition containing an organic filler. Restoration using dental composite resin (CR) (CR restoration) is rapidly spreading because it can reduce the amount of cutting of tooth material, can provide a color tone equivalent to natural tooth color, and is easy to operate. . In recent years, it has been used not only for restoration of anterior teeth, but also for posterior teeth to which high occlusal pressure is applied due to improvement in mechanical strength and improvement in adhesion to teeth.

  As described above, one of the outstanding features of CR restoration is that restoration with high aesthetics is possible, but natural teeth are composed of dentin and enamel, and the color tone (hue, saturation, In order to perform restoration with high aesthetics, it is necessary to take detailed measures according to the state of the tooth to be restored (tooth to be restored). For example, even when the restoration tooth is lightly damaged and the cavity is shallow, a plurality of CRs having different colors are prepared, and an actual restoration tooth and its adjacent teeth (hereinafter, also referred to as “around the restoration tooth”). ) And the one with the best color tone are generally selected and used (see Non-Patent Document 1). In addition, when the cavity is deep, the color tone of the tooth is not only the color of the tooth surface (enamel part), but also the color tone of the deep part (dentin part) that can be seen through, and it is viewed in a rich gradation. Therefore, the color tone of the curable paste to be filled is changed at a certain depth, and the subtle color tone is reproduced by laminating and filling (see Non-Patent Documents 1 and 2).

  In order to meet such demands, many CRs whose color tone has been prepared by adding a pigment substance or a dye substance while changing the kind or blending amount thereof have been provided. However, the CR in which the color tone is adjusted using a pigment substance or a dye substance is discolored or discolored due to aging of these substances in the CR cured product. May not be compatible with natural teeth.

  On the other hand, as a technique for coloring without using a pigment substance or a dye substance, coloring is performed by colored light (hereinafter, also simply referred to as "interference light") utilizing reflection, interference, scattering, transmission, and the like of light by fine particles in a medium. There is a technology that produces such a color (hereinafter, the color developed by such a principle is also referred to as “structural color”), and by applying these technologies, a composite material in which inorganic particles are dispersed in a medium such as a resin is used to obtain a desired color. There is also known a technique for developing a color (see Patent Document 1).

That is, Patent Document 1 includes, for example, “Polymerizable monomer component (A), inorganic spherical filler (B) having an average particle diameter in a range of 230 nm to 1000 nm, and polymerization initiator (C). more than 90% of the individual particles constituting the spherical filler (B) is present in the range of 5% before and after the average particle diameter, refractive index n _F in the 25 ° C. of inorganic spherical filler (B) is a polymer consists sex monomer component curable composition which satisfies the condition that is greater than the refractive index n _P at 25 ° C. of the polymer obtained by polymerizing (a) ", to form a cured body of the" thickness 1mm In this state, the lightness (V) of the colorimetric value of the colored light under the black background in the Munsell color system, measured using a color difference meter, is less than 5, and the chroma (C) is 0.05 or more. Yes, due to the Munsell color system of colored light under a white background Colorimetric values of lightness (V) is at least 6, a curable composition chroma (C) is less than 2 "is disclosed. Patent Document 1 discloses that CR composed of the above curable composition has the following problems: (1) the problem of discoloration with time is unlikely to occur because no dye substance or pigment substance is used; It can be colored yellow to red, which is the same color as the ivory color (depending on the particle size), and (3) the cured body is easily harmonized with the color of the tooth to be repaired, and complicated shade-taking and composite resin It is described that one type of composite resin has an excellent feature that a tooth to be repaired in a wide range of colors can be restored to an appearance close to that of a natural tooth without performing shade selection. Note that the curable composition disclosed in Patent Document 1 is designed to develop yellow-red colored light mainly for the purpose of repairing the cavity where the dentin is located in the deep part. As the inorganic spherical filler (B), those having an average particle diameter of 230 nm or more are used, but if the color tone is not particular, including the blue type, the structural color itself may have an average particle diameter of 100 nm or more. it can.

Patent No. 6250245 Hideo Matsumura, supervised sequentially by Taue, "Adhesion YEARBOOK 2006", 1st edition, Quintessence Publishing Co., Ltd., August 2006, p. 129-137 Shinji Miyazaki, "Science and Techniques for Restoring Composite Resins", 1st Edition, Quintessence Publishing Co., Ltd., January 2010, p. 48-49

  The curable composition disclosed in Patent Document 1 exhibits the above-mentioned excellent characteristics when used as CR. However, as described above, the curable composition is designed mainly for the purpose of restoring a cavity in which dentin is located in a deep part, and is intended to be a class III cavity (anterior tooth) in which dentin does not exist in a deep part. The suitability of color tone when used for repairing adjacent cavities with no incisal corners and in Class IV cavities (cavities with incisal corners in front of adjacent teeth) has not been studied.

  Then, the present inventors examined the color compatibility of the curable composition disclosed in Patent Document 1 in restoring anterior teeth (class III cavities and class IV cavities). Although it appears, the cause is probably that the transparency of the cured product is too high, making it difficult for reflected light and scattered light to reach the observer, but the repaired part looks black (the developed structural color is visually observed). Can not be recognized). Such a phenomenon is caused by introducing a layer structure into the restoration part, disposing a hardened material of low transparency CR on the base part (a part corresponding to the vicinity of the back side of the restoration tooth), and arranging the surface layer part (the front side of the restoration tooth). It is thought that this problem can be solved by disposing a CR made of the above-mentioned curable composition, but the operation is inevitably complicated.

  The present invention solves the above-described problem peculiar to CR for performing color tone adjustment based on a structural color, which has not been recognized so far, and uses a class III cavity without using a pigment substance or a dye substance. It is an object of the present invention to provide a dental curable composition that can be used as a CR that can obtain high color tone compatibility even when used for restoring an IV or IV class cavity.

  The present inventors have found that the curable composition disclosed in Patent Document 1 can solve the above-mentioned problem if the transparency of the obtained cured product can be reduced while maintaining its structural color developing function. We thought that we could do it, and we worked diligently. As a result, (1) the transparency of the cured product can be lowered by blending the amorphous inorganic filler having an average primary particle diameter in the range of 100 nm or more and 1000 nm or less, and (2) the transparency at that time is as follows. It can be adjusted by the average primary particle diameter of the amorphous inorganic filler and the compounding amount thereof. (3) When the transparency is reduced by adding the amorphous filler, as the degree of the reduction increases, (4) When the opacity is appropriately adjusted based on the knowledge of the above (2), it is possible to maintain the visibility of the appearing structural color, thereby solving the above-mentioned problem. The inventors have found that the present invention can be performed, and have completed the present invention.

That is, in the first invention, the polymerizable monomer component (A) has an average primary particle diameter in the range of 100 nm or more and 1000 nm or less, and 90% or more of the total number of particles in the number-based particle size distribution is the average primary particle diameter. An inorganic spherical filler (B) existing in a range of 5% before and after the particle diameter, an amorphous inorganic filler (C) having an average particle diameter in a range of 100 nm or more and 1000 nm or less, and a polymerization initiator (D). The refractive index at 25 ° C. of the inorganic spherical filler (B): n _FB is larger than the refractive index at 25 ° C. of a polymer obtained by polymerizing the polymerizable monomer component (A): n _P. It is a dental curable composition characterized by the following.

In the above-mentioned dental curable composition of the present invention, a cured product having a thickness of 1 mm obtained by curing the dental curable composition of the present invention from the viewpoint that effective visibility of the developed structural color can be maintained. was measured using a color difference meter for, in the spectral reflectance curve under black background, the maximum value of the spectral reflectance in the 600nm or 750nm or less in the wavelength region (yellow to red region): the SR _1, 400 nm or more 500nm or less wavelength range maximum value of the spectral reflectance in (blue region) in: SR ₂ with a value obtained by dividing the spectral reflectance ratio is defined _as: SR 1 / SR ₂ 0.8 to 2.0, especially in the range 0 It is preferable that the thickness be in the range of 0.9 to 1.5. In addition, from the viewpoint of exhibiting a yellow to red structural color with high intensity, the inorganic spherical filler (B) preferably has an average primary particle diameter of 230 nm or more and 350 nm or less, particularly preferably 245 nm or more and 300 nm or less. The total blending amount of the inorganic spherical filler (B) and the amorphous inorganic filler (C) is 100 parts by mass or more and 1500 parts by mass or less based on 100 parts by mass of the polymerizable monomer (A). It is preferable that the proportion of the compounding amount of the amorphous inorganic filler (C) occupying is 5% or more and 50% or less. Further, from the viewpoint that the color compatibility of the repaired part when the class III cavity or the class IV cavity is repaired by the cured body of the dental curable composition of the present invention becomes higher, the cured body having a thickness of 1 mm is the ratio of both when the Y stimulus value determined by tristimulus values measured by the color difference meter was black and white background and each Y _{b (black} background), and Y _{w (white} background) with Y b _/ Y _w It is preferable to provide a cured product having a defined contrast ratio of 0.30 to 0.70, particularly 0.4 to 0.6.

  A second present invention is a dental filling and restorative material for class III and / or IV class cavity restoration comprising the dental curable composition of the present invention, and a third present invention is a dental filling / restoring material of the present invention. It is a dental material for class III cavity and / or class IV cavity restoration composed of a cured product of a dental curable composition.

  The patent discloses that the dental curable composition of the present invention can achieve a color tone that is harmonized with the surroundings by only one type without using a dye substance or a pigment substance that causes a problem of fading. In addition to providing the same effect as the curable composition disclosed in Document 1, it has a moderate opacity, so that it can be used as a base material for repairing an anterior tooth defect, especially for a class III cavity or a class IV cavity. Without using CR, one type of restoration can be performed with high color tone compatibility with natural teeth.

The greatest feature of the present invention is that in a curable composition that exhibits a structural color as disclosed in Patent Document 1, an amorphous inorganic filler (C) having an average particle diameter in a range of 100 nm or more and 1000 nm or less is used. The point is that by adding the compound, an appropriate opacity is imparted to the obtained cured product so that the visibility of the developed structural color can be maintained. Thereby, an appropriate opacity imparted to the cured product, for example the cured material having a thickness of 1 mm, is determined by the tristimulus values measured by the color difference meter was the background with black and white Y stimulus value respectively Y _b ( black background), and _{Y w} (ratio of the two when a white _{background): Y} b / Y 0.3~0.7 the contrast ratio defined by _w, more preferably from 0.4 to 0.6 It can be. Moreover, since the opacity at this time is such that the effect of the interference light as described above can be maintained, an aesthetic restoration exhibiting a natural color tone can be achieved even for restoration of a class III cavity or a class IV cavity. .

As described above, the present invention is based on a curable composition that develops a structural color, and expresses the basic composition (each component and the amount thereof) and the structural color of the base curable composition. The conditions and the like to be satisfied are basically the same as those of the curable composition disclosed in Patent Document 1. That is, the dental curable composition of the present invention has a polymerizable monomer component (A) having an average primary particle diameter in the range of 100 nm or more and 1000 nm or less, and 90% or more of the total number of particles in the number-based particle size distribution. Contains an inorganic spherical filler (B) and a polymerization initiator (D) present in a range of 5% before and after the average primary particle diameter, and further has a refractive index at 25 ° C. of the inorganic spherical filler (B): n _FB is larger than n _P at 25 ° C. of a polymer obtained by polymerizing the polymerizable monomer component (A). By satisfying such conditions, the interference light without using a dye substance or a pigment substance, and thus the structural color based on the interference light can be clearly confirmed, and regardless of the depth of the cavity, it is close to a natural tooth. A dental curable composition that enables restoration with good color tone compatibility, particularly a curable composition for a dental filling and restoration material.

Here, it is considered that the relationship between the particle diameter of the inorganic spherical filler (B) and the light interference phenomenon is in accordance with the Bragg diffraction condition, and interference light having a color tone corresponding to the average primary particle diameter of the inorganic spherical filler (B) is generated. (The structural color is developed). The occurrence of interference light (the appearance of structural color) can be confirmed by measuring the spectral reflectance using a color difference meter. However, when the measurement is performed under a white background, it is necessary to perform the measurement under a black background because colored light due to interference is hardly observed due to strong scattered reflected light of external light (for example, C light source and D65 light source). . When measured under a black background, the reflection spectrum corresponding to the wavelength of the interference light generated when external light is absorbed or blocked can be clearly confirmed. In the case where the structural color of a specific color does not appear due to reasons such as not satisfying the condition of the refractive index, or adding only the amorphous filler and not adding the inorganic spherical filler (B), a black background is used. Doing spectral reflectance measurement, there is a tendency that the reflection of the relatively blue is strongly observed (spectral reflectance ratio of Comparative example 4-9: see SR 1 _/ SR _2), blue looking at the reflection spectrum Usually, the intensity in the wavelength region of the system is significantly higher than the intensity in the wavelength region of the yellow to red system. On the other hand, the curable composition disclosed in Patent Document 1 has a maximum in a wavelength range from yellow to red. In the present invention, although the expression of the structural color decreases due to the decrease in transparency (increase in opacity), the opacity is appropriately controlled, so that the intensity in the yellow to red wavelength region is reduced to the blue wavelength region. The level is equal to or higher than the strength, and high color tone compatibility can be obtained.

  Hereinafter, each component of the dental curable composition of the present invention will be described.

<Polymerizable monomer component (A)>
Known polymerizable monomer components (A) can be used without particular limitation. From the viewpoint of polymerization rate, radically polymerizable or cationically polymerizable monomers are preferred from the viewpoint of dental use. Particularly preferred radically polymerizable monomers include the following (meth) acrylates which are (meth) acrylic compounds, and particularly preferred cationically polymerizable monomers include epoxies and oxetanes. . Generally, (meth) acrylates that are preferably used include, for example, the following (a) to (d) when (meth) acrylates are exemplified.

(A) Monofunctional polymerizable monomer (ii) Those having no acidic group or hydroxyl group Methyl (meth) acrylate, 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, methoxy-triethylene Glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, ethoxyethylene glycol (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, ethoxytriethylene glycol ( TA) acrylate, ethoxy polyethylene 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, and the like.

(I-ii) Having an acidic group (meth) acrylic acid, N- (meth) acryloylglycine, N- (meth) acryloylaspartic acid, N- (meth) acryloyl-5-aminosalicylic acid, 2- (meth) Acryloyloxyethyl hydrogen succinate, 2- (meth) acryloyloxyethyl hydrogen phthalate, 2- (meth) acryloyloxyethyl hydrogen malate, 6- (meth) acryloyloxyethyl naphthalene-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- (meta ) 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 carboxyl groups of these compounds into acid anhydride groups; 11- (meth) acryloyloxyundecane-1,1-dicarboxylic acid; 10- (meth) acryloyloxydecane-1,1-dicarboxylic acid; (Meth) acryloyloxidedecane-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) acryloyloxye Tylnaphthalene-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) acryloyloxyethyl phenyl hydrogen phosphate, 10- (meth) acryloyloxydecyl dihydrogen phosphate Fate, 6- (meth) acryloyloxyhexyl dihydrogen phosphate, 2- (meth) acryloyloxyethyl-2-bromoethyl hydrogen phosphate, 2- (meth) acrylamidoethyl dihydrogen phosphate, 2 (Meth) acrylamide-2-methylpropanesulfonic acid, 10-sulfodecyl (meth) acrylate, 3- (meth) acryloxypropyl-3-phosphonopropionate, 3- (meth) acryloxypropylphosphonoacetate, -(Meth) acryloxybutyl-3-phosphonopropionate, 4- (meth) acryloxybutylphosphonoacetate, 5- (meth) acryloxypentyl-3-phosphonopropionate, 5- (meth) Acryloxypentyl phosphonoacetate, 6- (meth) acryloxyhexyl-3-phosphonopropionate, 6- (meth) acryloxyhexylphosphonoacetate, 10- (meth) acryloxydecyl-3-phosphonopro Pionate, 10- (meth) acryloxydecyl phosphonoacetate, 2- (Meth) acryloxyethyl-phenylphosphonate, 2- (meth) acryloyloxyethylphosphonic acid, 10- (meth) acryloyloxydecylphosphonic acid, N- (meth) acryloyl-ω-aminopropylphosphonic acid, 2- (meth) Acryloyloxyethyl phenylhydrogen phosphate, 2- (meth) acryloyloxyethyl 2′-bromoethyl hydrogen phosphate, 2- (meth) acryloyloxyethyl phenyl phosphonate and the like.

(I-iii) Those having a hydroxyl group 2-hydroxyethyl (meth) acrylate, 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 and the like.

(B) Bifunctional polymerizable monomers (b-i) aromatic compounds 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, (4-methacryloyloxydiethoxyphenyl) -2 ( -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; methacrylates such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and 3-chloro-2-hydroxypropyl methacrylate; Vinyl monomers having an -OH group such as the corresponding acrylate, and diisocyanate methylbenzene and 4,4'-diphenylmethane diisocyanate. Diadduct obtained from the addition of the diisocyanate compound having an aromatic group; di (methacrylate b carboxyethyl) diphenylmethane urethane.

(B-ii) Aliphatic Compounds 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; 2-hydroxyethyl methacrylate, 2-hydroxy, such as 1,6-bis (methacrylethyloxycarbonylamino) trimethylhexane Methacrylates such as propyl methacrylate and 3-chloro-2-hydroxypropyl methacrylate, and acrylates corresponding to these methacrylates. Diadduct obtained from an adduct of a vinyl monomer having an -OH group such as acrylate and a diisocyanate compound such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, diisocyanatomethylcyclohexane, isophorone diisocyanate, and methylene bis (4-cyclohexyl isocyanate) 1,2-bis (3-methacryloyloxy-2-hydroxypropoxy) ethyl and the like.

(C) Trifunctional polymerizable monomers Methacrylates such as trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, pentaerythritol trimethacrylate, trimethylolmethane trimethacrylate, and acrylates corresponding to these methacrylates.

(D) tetrafunctional polymerizable monomer pentaerythritol tetramethacrylate, pentaerythritol tetraacrylate; diisocyanatemethylbenzene, diisocyanatemethylcyclohexane, isophorone diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, methylene bis (4-cyclohexyl isocyanate), Diadducts obtained from adducts of diisocyanate compounds such as 1,4-diphenylmethane diisocyanate and tolylene-2,4-diisocyanate with glycidol dimethacrylate.

  A plurality of these polyfunctional (meth) acrylate-based polymerizable monomers may be used in combination, if necessary. Further, if necessary, methacrylates such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, hydroxyethyl methacrylate, tetrahydrofurfuryl methacrylate, and glycidyl methacrylate, and monofunctional (meth) acrylate based acrylates such as acrylates corresponding to these methacrylates. Polymers or polymerizable monomers other than the above (meth) acrylate monomers may be used.

In the present invention, a plurality of types of polymerizable monomers are generally used as the polymerizable monomer component (A) in order to adjust the physical properties (mechanical properties and adhesion to teeth) of the cured product. At this time, it is desirable to set the type and amount of the polymerizable monomer such that the refractive index of the component (A) at 25 ° C. is in the range of 1.38 to 1.55. That is, by setting the refractive index in the range of 1.38 to 1.55, the refractive index n _P of the polymer obtained from the polymerizable monomer component (A) can be approximately 1.40 to 1.57. The range can be set, and it becomes easy to satisfy the condition of n _P <n _FB . In some cases, a plurality of types of polymerizable monomers may be used as the polymerizable monomer component (A). In this case, the refractive index of the polymerizable monomer component (A) may be a plurality of types of polymerizable monomers. It is sufficient that the refractive index of the mixture obtained by mixing the bodies is within the above range, and the individual polymerizable monomers do not necessarily need to be within the above range. 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.

<Inorganic spherical filler (B)>
The dental curable composition contains various fillers such as inorganic powders and organic powders, but the dental curable composition of the present invention has the purpose of expressing colored light due to interference. And an inorganic spherical filler (B) having an average primary particle diameter in a range of 100 nm or more and 1000 nm or less. The inorganic spherical filler (B) is spherical, and is narrow such that 90% or more of the number of individual particles constituting the inorganic spherical filler (B) exists in a range of 5% before and after the average primary particle diameter. By having a particle size distribution, the particles are dispersed so as to have a short-range regularity, and it becomes possible to generate interference light having a specific wavelength according to the average primary particle size. Here, the average primary particle diameter of the inorganic spherical filler (B) is determined by taking a photograph of a powder with a scanning electron microscope and selecting 30 or more particles observed in a unit field of view of the photograph. It refers to the average value of the primary particle diameter (maximum diameter). The spherical shape may be a substantially spherical shape, and need not necessarily be a perfect sphere. Take a photograph of the particles with a scanning electron microscope, measure the maximum diameter of each particle (30 or more) within the unit field of view, and divide the particle diameter in the direction perpendicular to the maximum diameter by the maximum diameter The degree of uniformity may be 0.6 or more, more preferably 0.8 or more.

  The number-based particle size distribution of the inorganic spherical filler (B) is not particularly limited as long as the ratio of the number of particles existing in the range of 5% before and after the average primary particle diameter to the total number of particles is 90% or more. The ratio is preferably at least 91%, more preferably at least 93%.

  The manifestation of colored light due to light diffraction and interference is due to diffraction and interference occurring in accordance with Bragg conditions, and light of a specific wavelength is emphasized. Colored light (interference light) is generated in the cured body of the conductive composition, and a structural color corresponding to the particle diameter is developed.

  The average primary particle diameter of the inorganic spherical filler (B) may be in the range of 100 nm or more and 1000 nm or less. When spherical particles having an average primary particle diameter of less than 100 nm are used, a visible light interference phenomenon hardly occurs. On the other hand, when an inorganic spherical filler having an average primary particle diameter of more than 1000 nm is used, the occurrence of light interference phenomenon can be expected, but when used as a restoration material for dental filling, sedimentation and polishing of the inorganic spherical filler can be expected. A drop occurs.

  According to the study of the present inventors, the color tone of the structural color developed when the inorganic spherical filler (B) is used is in the range of 100 nm to 1000 nm depending on the average primary particle diameter of the inorganic spherical filler used. It has been found that the intensity changes in the repetition cycle of blue, yellow, and red as the size increases, and the strength tends to decrease in the cycle with a large average primary particle size. Therefore, the average primary particle diameter is preferably 100 nm or more and 500 nm or less from the viewpoint of exhibiting a strong structural color. Further, from the viewpoint of strongly exhibiting yellow to red structural colors, the average primary particle diameter is preferably 230 nm or more and 350 nm or less, particularly preferably 245 nm or more and 300 nm or less.

  For example, when spherical particles having an average primary particle diameter in the range of 230 nm to 260 nm are used, the obtained colored light is yellowish, and falls in the category of B-type (red-yellow) in a shade guide (“VITAClassical”, manufactured by VITA). It is useful for the restoration of certain teeth, especially for the restoration of cavities formed from enamel to dentin. When spherical particles having an average primary particle diameter in the range of 260 nm to 350 nm are used, the resulting colored light is reddish, and the teeth are in the category A (reddish-brown) in a shade guide (“VITAClassical”, manufactured by VITA). It is especially useful for repairing cavities formed from enamel to dentin. Since the color of the dentin is often reddish, the use of the inorganic spherical filler (B) having an average primary particle diameter in the above-mentioned preferred range allows a wide compatibility with restoring teeth of various colors. Can be better.

  As the inorganic spherical filler (B), those used as components of a usual dental curable composition can be used without limitation. Specifically, amorphous silica, silica / titanium group element oxide-based composite oxide particles (silica / zirconia, silica / titania, etc.), quartz, alumina, barium glass, strontium glass, lanthanum glass, fluoroaluminosilicate glass And inorganic powders such as ytterbium fluoride, zirconia, titania, and colloidal silica. Of these, silica-titanium group element oxide-based composite oxide particles are preferable because the refractive index of the filler is easily adjusted.

  Here, the silica / titanium group element oxide-based composite oxide particles are composite oxides of silica and a titanium group element (group 4 element of the periodic table), and include silica / titania, silica / zirconia, Silica, titania, zirconia and the like can be mentioned. Among them, silica / zirconia is preferable because the refractive index of the filler can be adjusted and high X-ray opacity can be imparted. The composite ratio is not particularly limited, but from the viewpoint of imparting sufficient X-ray opacity and adjusting the refractive index to a preferable range described below, the content of silica is 70 to 95 mol%, and the titanium group is used. Those having an element oxide content of 5 to 30 mol% are preferred. In the case of silica / zirconia, the refractive index can be freely changed by changing each composite ratio in this way.

  In addition, these silica / titanium group element oxide-based composite oxide particles can also be used in a small amount in combination with a metal oxide other than silica and titanium group element oxide. Specifically, an alkali metal oxide such as sodium oxide and lithium oxide may be contained within 10 mol%.

  The method for producing such silica / titanium group element oxide-based composite oxide particles is not particularly limited. For example, a mixed solution containing a hydrolyzable organosilicon compound and a hydrolyzable organic titanium group metal compound is treated with an alkaline solution. A so-called sol-gel method, in which a reaction product is precipitated by adding the compound to a solvent and performing hydrolysis to cause hydrolysis, is suitably employed.

  These silica / titanium group oxide-based composite oxide particles may be surface-treated with a silane coupling agent. By the surface treatment with the silane coupling agent, the interface strength between the polymerizable monomer (A) and the cured body becomes excellent. Representative silane coupling agents include organic silicon compounds such as γ-methacryloyloxyalkyltrimethoxysilane and hexamethyldisilazane. The amount of surface treatment of these silane coupling agents is not particularly limited, and the optimal values may be determined after confirming the mechanical properties and the like of the obtained dental curable composition in advance by experiments, but a preferred range is exemplified. If so, it is in the range of 0.1 to 15 parts by mass with respect to 100 parts by mass of the particles.

In the dental curable composition of the present invention, in order to generate interference light or develop a structural color, the refractive index of the inorganic spherical filler (B) at 25 ° C .: n _FB is the polymerizable monomer. refractive index at 25 ° C. of the polymer obtained by polymerizing the component (a): there is a need greater than n _P. That is, it is necessary to satisfy the relationship of n _P <n _FB . Difference between n _FB and n _P : n _FB −n _P is preferably 0.001 or more, more preferably 0.002 or more, and most preferably 0.005 or more.

  In the dental curable composition of the present invention, the inorganic spherical filler (B) may be blended as it is, but may be obtained by previously mixing and polymerizing with the polymerizable monomer (A) or the like. May be compounded in the form of an organic-inorganic composite filler comprising the composite obtained.

  The method for producing the organic-inorganic composite filler is not particularly limited. For example, a method of mixing predetermined amounts of the inorganic spherical filler (B), the polymerizable monomer, and each component of the polymerization initiator, and heating, irradiating light, and the like. After polymerization, a general production method of pulverizing can be adopted. Alternatively, the production method described in WO 2011/115007 or WO 2013/039169 can also be adopted. In this production method, the inorganic aggregated particles obtained by agglomeration of the spherical inorganic filler, the polymerizable monomer, a polymerization initiator, and after immersing in a polymerizable monomer solvent containing an organic solvent, the organic solvent is removed, The polymerizable monomer is polymerized and cured by a method such as heating or light irradiation. According to the production method described in WO 2011/115007 or WO 2013/039169, the inorganic primary particles cover the surface of each inorganic primary particle of the aggregated inorganic particles, and each inorganic primary particle is An organic-inorganic composite filler having an organic resin phase bonded to each other and having an aggregation gap formed between the organic resin phases covering the surface of each inorganic primary particle is obtained.

<Amorphous inorganic filler (C)>
The dental curable composition of the present invention is blended with an amorphous inorganic filler (C) having an average particle diameter in the range of 100 nm to 1000 nm for imparting appropriate opacity to the cured product. Here, the amorphous means that the shape of the primary particles observed by SEM or the like has a large number of irregular corners and faces, and the amorphous inorganic filler (C) is usually It means a filler composed of particles obtained by crushing or grinding. The average particle diameter of the amorphous filler (C) was measured by a laser scattering method (for example, LS230 manufactured by Beckman Coulter Co., Ltd. was used as a measuring device, and ethanol was used as a dispersion medium). D50). Specifically, first, 0.01 to 1 g of a measurement sample is added to 5 ml of ethanol as a dispersion medium, and the liquid in which the sample is suspended is subjected to a dispersion treatment for about 1 to 5 minutes by an ultrasonic disperser, and the dispersion of 0.04 The particle size distribution of particles with a size in the range of 〜2000 μm is measured. Then, a cumulative distribution is drawn from the smaller diameter side for each of the particle size ranges divided based on the obtained particle size distribution, and the particle size at which the cumulative value is 50% is defined as the average particle size (D50).

  In order to exhibit the effects of the present invention, the average particle diameter of the amorphous inorganic filler (C) needs to be in the range of 100 nm to 1000 nm. When the average particle diameter of the amorphous inorganic filler is less than 100 nm, it is not possible to impart appropriate opacity to the cured product. On the other hand, if the thickness exceeds 1000 nm, the opacity of the cured product becomes too high, and if interference light is not generated, the structural color caused by the interference light cannot be visually recognized. The average particle diameter of the amorphous inorganic filler (C) is preferably from 100 to 1,000 nm, and more preferably from 200 to 900 nm from the viewpoint that appropriate opacity can be imparted to the cured product while ensuring the visibility of the structural color. More preferably, it is 300 nm or more and 700 nm or less.

Here, as an index of “opacity” given to the cured body of the dental curable composition of the present invention, a contrast ratio (Y _b / Y _w ) measured in a state of a cured body having a thickness of 1 mm. Can be used. Here Y _b, for curing of thick 1 mm, mean Y stimulus value determined by tristimulus values measured by the color difference meter was the background with black, Y _w is when measured in the same manner the background as white Means Y stimulus value. Contrast ratio (Y b _{/ Y w)} is in the case of less than 0.3, for example lightness of the cured body at the repair site (filling sites) in the case of using the repair of Class III cavity and IV class cavity (shades of colors) , The transmitted light at the site is strong, and the colored light from the cured body is weak, so that it is difficult to obtain good color tone compatibility. When the contrast ratio exceeds 0.7, the brightness of the cured product increases, the reflected light on the surface of the repaired portion (filled portion) becomes strong, and the colored light from the cured product becomes weak. It becomes difficult to obtain color compatibility. Therefore, it can be said that when the contrast ratio _(Y b / Y _w) is in the range of 0.30 to 0.70 is "suitable opacity" as described above. In class III cavity and IV class cavity restoration, in order to have a good color tone compatibility, the contrast ratio _(Y b / Y _w) is preferably in the range of 0.35 to 0.65, 0 More preferably, it is in the range of from .40 to 0.60.

  Further, in the cured product of the dental curable composition of the present invention, the opacity is increased by adding the amorphous inorganic filler (C), but the visibility of the structural color is maintained. That is, the interference light generated in the cured body or the structural color developed in the cured body can be confirmed by a spectral reflectance curve on a black background measured with a color difference meter for the cured body having a thickness of 1 mm. it can. As described above, as the structural color, a color tone according to the size of the average primary particle diameter of the inorganic spherical filler (B) (usually, from a wide range of color tones such as blue to yellow to red) depending on the purpose. Structural color of the selected preferred color tone) is developed, and reflection in a wavelength region corresponding to the color tone is significantly higher in reflection reflectance measurement using a color difference meter under a black background.

When the dental curable composition of the present invention is used for repairing, for example, a class III cavity or a class IV cavity, the cured product can be confirmed to have a suitable opacity as described above and can be confirmed to be yellow to red. It is preferable to develop a (visible) structural color for performing aesthetic restoration with high color tone compatibility. From such a viewpoint, the dental curable composition of the present invention preferably gives a cured product having a spectral reflectance ratio: SR ₁ / SR _{2 in} the range of 0.8 or more and 2.0 or less. Here, the above SR ₁ and SR ₂ are the spectral reflectances under a black background, measured using a color difference meter on a cured product having a thickness of 1 mm obtained by curing the dental curable composition of the present invention. In the curves, the maximum value of the spectral reflectance (SR ₁ ) in the wavelength region of 600 nm or more and 750 nm or less (yellow-red region) and the maximum value of the spectral reflectance (SR in the wavelength region of 400 nm or more and 500 nm or less (blue region)) ₂ ) means When the spectral reflectance ratio is less than 0.8, yellow to red colored light is weak, and it tends to be difficult to obtain color tone compatibility with yellow or reddish natural teeth. When the spectral reflectance ratio exceeds 2.0, the yellow to red colored light is too intense, so that it is difficult to obtain good color tone compatibility. In order to have excellent color tone compatibility when used for repairing a class III cavity or a class IV cavity, the spectral reflectance ratio is more preferably in the range of 0.9 or more and 1.5 or less.

  The material of the amorphous inorganic filler (C) is not particularly limited, and known materials can be used. Specifically, borosilicate glass, soda glass, glass containing heavy metals (for example, barium, strontium, zirconium), aluminosilicate glass, fluoroaluminosilicate glass, glass ceramics, metal fluorides such as ytterbium fluoride, yttrium fluoride, Preferred are silica and composite inorganic oxides such as silica-zirconia, silica-titania, and silica-alumina. A particularly preferred example is a composite oxide containing silica and zirconia as main components, since a cured product having X-ray imaging properties and more excellent abrasion resistance can be obtained.

  The amorphous inorganic filler (C) is preferably used after its surface is treated with an appropriate surface treating agent for the purpose of improving dispersibility in a polymerizable monomer as a matrix. The method for the treatment can be used without any limitation as in the method described above for the surface treatment of the substantially spherical inorganic filler.

  The total compounding amount of the inorganic spherical filler (B) and the amorphous inorganic filler (C) in the invention is 100 parts by mass or more and 1500 parts by mass or less, particularly 100 parts by mass, based on 100 parts by mass of the polymerizable monomer (A). It is preferable that the amount is not less than 1000 parts by mass and not more than 1000 parts by mass. It is preferable that the compounding amount of the inorganic spherical filler (B) is larger than the compounding amount of the amorphous inorganic filler (C) from the viewpoint that the structural color is well expressed. In addition, the inorganic filler (B) and the amorphous inorganic filler (C) are combined with each other because they exhibit a natural color tone for the restoration of the class III cavity and the class IV cavity, thereby enabling more aesthetic restoration. It is preferable that the amorphous inorganic filler (C) is blended so that the proportion of the blended amount of the amorphous inorganic filler (C) is 5% or more and 50% or less, particularly 10% or more and 40% or less.

<Polymerization initiator (D)>
The polymerization initiator (D) is not particularly limited as long as it has a function of polymerizing the polymerizable monomer (A), but the light used for direct filling and restorative use in dentistry is often cured in the oral cavity. It is preferable to use a polymerization initiator or a chemical polymerization initiator, and it is more preferable to use a photopolymerization initiator (composition) from the viewpoint that there is no need for a mixing operation and that it is simple.

  Examples of the polymerization initiator used for photopolymerization include benzoin alkyl ethers such as benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether; benzyl ketals such as benzyl dimethyl ketal and benzyl diethyl ketal; benzophenone; and 4,4′-dimethylbenzophenone. Α-diketones such as dibenzo, 2,3-pentadionebenzyl, camphorquinone, 9,10-phenanthraquinone, and 9,10-anthraquinone; Thioxanthone compounds such as ethoxythioxanthone, 2-chlorothioxanthone and methylthioxanthone; bis- (2,6-dichlorobenzoyl) phenylphosphine oxide; Zoyl) -2,5-dimethylphenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -4-propylphenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -1-naphthylphosphine oxide, bis (2 Bisacylphosphine oxides such as (4,4-trimethylbenzoyl) -phenylphosphine oxide.

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

  Further, there are often cases where a photoacid generator is used in addition to the photopolymerization initiator and the reducing compound. Examples of such a photoacid generator include a diaryliodonium salt-based compound, a sulfonium salt-based compound, a sulfonic acid ester compound, a halomethyl-substituted-S-triazine derivative, and a pyridinium salt-based compound.

  These polymerization initiators may be used alone or in combination of two or more. The amount of the polymerization initiator may be selected in an effective amount according to the purpose, but is usually 0.01 to 10 parts by mass relative to 100 parts by mass of the polymerizable monomer, and more preferably 0.1 to 10 parts by mass. It is used in a proportion of up to 5 parts by mass.

<Other additives>
The dental composite restorative material of the present invention may contain other known additives in addition to the components (A) to (D) as long as the effect is not impaired. Specific examples include a polymerization inhibitor and an ultraviolet absorber. Further, for the purpose of adjusting the viscosity or the like, a filler having a particle diameter sufficiently smaller than the wavelength of light and hardly affecting the color tone and transparency can be blended.

  According to the present invention, as described above, a single paste (a hardenable dental composition) can be used for restoration with good color tone compatibility with natural teeth without using a coloring substance such as a pigment. Therefore, an embodiment in which a pigment which may change color with time is not blended is preferred. However, in the present invention, the blending of the pigment itself is not denied, and a pigment that does not hinder the colored light due to interference of the inorganic spherical filler may be blended. Specifically, about 0.0005 to 0.5 part by mass, preferably about 0.001 to 0.3 part by mass, per 100 parts by mass of the polymerizable monomer, the pigment may be blended. .

  The dental curable composition of the present invention can be prepared by weighing and mixing a predetermined amount of the components (A) to (D). At this time, it is preferable that the inorganic spherical filler (B) and the amorphous inorganic filler (C) are mixed under the condition of being dispersed in the polymerizable monomer (A). In addition, from the viewpoint that good color tone compatibility, which is the effect of the present invention, is easily obtained without lowering the visibility of the developed structural color, the dental curable composition of the present invention is defoamed under reduced pressure. In this case, it is preferable to prepare such that bubbles of 1000 nm or more are not substantially contained.

  The dental curable composition of the present invention is particularly preferably used as a dental filling and restorative material represented by the photocurable composite resin as described above, but is not limited thereto, and may be used for other purposes. It can be suitably used. Examples of its use include dental cement, restorative materials for abutment construction, and the like.

  Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited to these Examples.

First, methods for measuring various physical properties in Examples and Comparative Examples will be described.
(1) Average Particle Diameter of Inorganic Spherical Filler A photograph of the powder was taken with a scanning electron microscope (manufactured by Philips, "XL-30S"), and the number of particles (30 or more) observed in a unit field of view of the photograph ) And the primary particle diameter (maximum diameter) were measured, and the average particle diameter was calculated by the following formula based on the measured values.

(2) Proportion of particles existing in the range of 5% before and after the average primary particle diameter in the inorganic spherical filler (B) First, individual particles (30 or more) observed in the unit field of view of the photograph described above. The primary particle diameter is measured, and the number of particles whose primary particle diameter is less than 95% of the average primary particle diameter determined in the above (1), and the primary particle diameter exceeds 105% of the average primary particle diameter The number of particles was measured, and the total number was determined. Next, by subtracting the total number from the total number of particles (30 or more) observed in the unit visual field of the photograph, the number of particles existing in a range of 5% before and after the average primary particle diameter in the number-based particle size distribution is calculated. Finally, the ratio (%) of the number of particles to the total number of particles was determined, and the ratio (%) of particles existing in a range of 5% before and after the average primary particle diameter was determined.

(3) Uniformity A photograph of the powder was taken with a scanning electron microscope (manufactured by Philips, "XL-30S"), and for each particle (30 or more) within the unit field of view of the photograph, the maximum diameter was determined. The average of the values obtained by dividing the particle diameter in the orthogonal direction by the maximum diameter was defined as the uniformity.

(4) Measurement of refractive index <Refractive index of polymerizable monomer component (A)>
The refractive index of the used polymerizable monomer (or a mixture of the polymerizable monomers) was measured in a constant temperature chamber at 25 ° C. using an Abbe refractometer (manufactured by Atago).
<Refractive index n _P of polymer of polymerizable monomer component (A)>
A polymer sample obtained by polymerizing the polymerizable monomer component (polymerizable monomer or mixture of polymerizable monomers) used under the same polymerization conditions as those in the cavity was used for the Abbe refractometer. It was determined measured by refractive index n _P in a constant temperature chamber of 25 ° C. using (Atago Co., Ltd.).
That is, a uniform composition obtained by mixing the polymerizable monomer component (A) with 0.3% by mass of CQ, 1.0% by mass of DMBE, and 0.15% by mass of HQME based on the mass of the component is obtained. And a mold having a hole of φ7 mm × 0.5 mm, and a polyester film was pressed against both sides. Thereafter, the film was irradiated with light for 30 seconds using a halogen-type dental light irradiator (Demetron LC, manufactured by Cybron) having a light amount of 500 mW / cm ² , cured, and then removed from the mold to prepare a polymer sample. In setting the refractive index, when the sample was set in the apparatus, bromonaphthalene (a solvent that did not dissolve and had a higher refractive index than the sample) was dropped on the sample in order to adhere the polymer to the measurement surface. .
<The refractive index of the inorganic spherical filler is _nFB and the refractive index of the amorphous inorganic filler>
The refractive index of the used inorganic spherical filler and amorphous inorganic filler was measured by a liquid immersion method using an Abbe refractometer (manufactured by Atago).
That is, in a 25 ° C. constant temperature room, 1 g of the inorganic spherical filler or its surface-treated product is dispersed in 50 ml of anhydrous toluene in a 100 ml sample bottle. While stirring the dispersion with a stirrer, 1-bromotoluene was added dropwise little by little, and the refractive index of the dispersion at the time when the dispersion became most transparent was measured. The obtained value was determined as the inorganic spherical filler and the amorphous inorganic filler. The refractive index of the filler was used.

(5) a paste of the contrast ratio (Y b _{/ Y w)} Evaluation Examples and curable compositions prepared in Comparative Examples of the curable composition placed in a mold having a through-hole of 7 mm × 1 mm, both sides The polyester film was pressed. After irradiating both sides for 30 seconds with a visible light irradiator (manufactured by Tokuyama, power light) and curing, remove from the mold and use a color difference meter (manufactured by Tokyo Denshoku, “TC-1800MKII”) to cure the above. The body tristimulus Y values (background black and white) were measured. The resulting background color black Y values _{(Y b)} and background fair Y value based on _{(Y w)} was calculated contrast ratio _(Y b / Y _w).

(6) Visual Evaluation of Colored Light (Interference Light) The paste of the dental curable composition prepared in each of Examples and Comparative Examples was placed in a mold having a hole of 7 mmφ × 1 mm, and both sides were pressed with a polyester film. After irradiating both sides for 30 seconds with a visible light irradiator (manufactured by Tokuyama, power light) and curing it, remove it from the mold, place it on an adhesive surface of black tape (carbon tape) of about 10 mm square, and color it visually. The color of light was confirmed.

(7) the spectral reflectance ratio _(SR 1 / _SR 2 in the black background)
The pastes of the curable compositions prepared in Examples and Comparative Examples were placed in a mold having a 7 mmφ × 1 mm through-hole, and a polyester film was pressed against both sides. After irradiating both sides with a visible light irradiator (manufactured by Tokuyama, power light) for 30 seconds and curing, remove from the mold and use a color difference meter (manufactured by Tokyo Denshoku, "TC-1800MKII") to obtain a black background. measuring the spectral reflectance under, the maximum value of the reflectance of the yellow to red range (600-750nm): SR ₁ and the maximum value of the reflectance in the blue range (400-500 nm): seeking SR _2, the SR ₁ It was calculated spectral reflectance ratio by dividing the SR _2.

(8) Evaluation of Colored Light (Interference Light) Based on Spectral Reflectance on White Background Paste of the curable composition prepared in each of Examples and Comparative Examples was put into a mold having a through hole of 7 mmφ × 1 mm, and polyester was coated on both sides. The film was pressed. After irradiating both sides for 30 seconds with a visible light irradiator (manufactured by Tokuyama, power light) and curing, take out from the mold and use a color difference meter (manufactured by Tokyo Denshoku, "TC-1800MKII") on a white background. The spectral reflectance was measured below.

(9) Bending strength The dental curable composition paste was filled in a stainless steel mold using a filler, and pressed with polypropylene, using a visible light irradiator power light (manufactured by Tokuyama Corporation). Light irradiation was performed for 30 seconds × 3 times from one side while changing the place so that the light hit the entire surface and closely contacting the polypropylene. Next, light irradiation was performed for 30 seconds × 3 times in the same manner as described above from the opposite surface while being in close contact with the polypropylene to obtain a cured product. Using a # 1500 water-resistant abrasive paper, the cured product was shaped into a 2 × 2 × 25 mm prism to obtain a sample piece. The obtained test piece was mounted on a testing machine (manufactured by Shimadzu Corporation, Autograph AG5000D), and three-point bending strength was measured at a fulcrum distance of 20 mm and a crosshead speed of 1 mm / min to obtain a load-deflection curve. The bending strength: σ _B (Pa) and the flexural modulus: E _B (Pa) were determined by the following equations. In addition, it evaluated about five test pieces and made the average value the bending strength.

However, the meaning and unit of each symbol in the above formula are as shown below.
P: Load at break of test piece (N)
S: distance between supporting points (m)
W: width of test piece (m)
B: thickness of test piece (m)
F / Y: slope (N / m) of the linear portion of the load-deflection curve.

(10) Evaluation of color tone compatibility Using a model tooth for tooth restoration that reproduced the No. 1 upper right class IV cavity (width 3 mm, height 3 mm), fill a defective part with a hardening paste, harden, grind, and color Suitability was checked visually. The model tooth for tooth restoration is in the category of series A (reddish brown) in the shade guide “VITAPAN Classical”, and has a high hue and high chroma, a high chromaticity model tooth (equivalent to A4), and a low hue and low hue. Saturation low chromaticity model tooth (equivalent to A1) and shade type "VITAPAN Classical" in the category of B type (red yellow), high hue and high saturation high chromaticity model tooth (equivalent to B4) A low hue and low chroma low chromaticity model tooth (equivalent to B1) was used.
◎: The color tone of the restoration matches well with the model tooth for tooth restoration.
○: The color tone of the restoration is similar to that of the model tooth for tooth restoration.
Δ: The color tone of the restoration is similar to that of the model tooth for tooth restoration, but the compatibility is not good.
×: The color tone of the restoration does not match the tooth restoration model tooth.

Next, abbreviations and substance names of polymerizable monomers, polymerization initiators, and the like used in Examples and Comparative Examples are shown below.
[Polymerizable monomer]
UDMA: 1,6-bis (methacrylethyloxycarbonylamino) trimethylhexane 3G: triethylene glycol dimethacrylate bis-GMA: 2,2-bis [(3-methacryloyloxy-2-hydroxypropyloxy) phenyl] Propane [polymerization initiator]
CQ: camphorquinone DMBE: N, N-dimethyl p-ethyl benzoate.
[Polymerization inhibitor]
HQME: hydroquinone monomethyl ether.

  Matrices M1 and M2 were prepared by mixing polymerizable monomers as shown in Table 1.

[Inorganic spherical filler]
The inorganic spherical filler is prepared by the method described in JP-A-58-110414, JP-A-58-156524, etc., with a hydrolyzable organic silicon compound (such as tetraethyl silicate) and a hydrolyzable organic titanium. A mixed solution containing a group III metal compound (such as tetrabutyl zirconate or tetrabutyl titanate) is added to an ammoniacal alcohol (eg, methanol, ethanol, isopropyl alcohol, isobutyl alcohol, etc.) solution into which ammonia water has been introduced, It was prepared by using a so-called sol-gel method in which a reaction product was precipitated by hydrolysis.

[Amorphous inorganic filler]
The preparation of amorphous silica-zirconia is performed by dissolving an alkoxysilane compound in an organic solvent and adding water thereto to partially hydrolyze according to the method described in JP-A-2-132102, JP-A-3-197311, and the like. After the decomposition, an alkoxide of another metal to be complexed and an alkali metal compound are further added to hydrolyze to form a gel, and then the gel is dried, crushed if necessary, and calcined. Prepared. The amorphous barium glass was prepared by pulverizing and classifying commercially available barium glass (GM8235, manufactured by Schott) as necessary. The amorphous ytterbium fluoride was prepared by pulverizing and classifying commercially available ytterbium trifluoride (manufactured by Tribach) as necessary.
Table 2 shows the inorganic spherical fillers used in Examples and Comparative Examples, and Table 3 shows the amorphous inorganic fillers.

Examples 1 to 17
To 100 g of the polymerizable monomer M1 or M2, 0.3% by mass of CQ, 1.0% by mass of DMBE, and 0.15% by mass of HQME are added and mixed to form a uniform polymerizable monomer. A composition was prepared. Next, the fillers shown in Tables 2 and 3 were weighed into a mortar, and the polymerizable monomer composition was gradually added under red light. A curable paste was used. The paste was further defoamed under reduced pressure to remove air bubbles, thereby producing a dental curable composition. The physical properties of the obtained dental curable composition were evaluated based on the above methods. The compositions and results are shown in Tables 4 and 5. The numerical values in parentheses in Table 4 represent the blending amounts (unit: parts by mass) of each component.

Comparative Examples 1 to 9
To 100 g of the polymerizable monomer M1, 0.3% by mass of CQ, 1.0% by mass of DMBE, and 0.15% by mass of HQME are added and mixed to obtain a uniform polymerizable monomer composition. Was prepared. Next, each filler shown in Table 4 is weighed in a mortar, and the polymerizable monomer composition is gradually added under red light, and is sufficiently kneaded in a dark place to obtain a uniform curable paste. And The paste was further defoamed under reduced pressure to remove air bubbles, thereby producing a dental curable composition. The physical properties of the obtained dental curable composition were evaluated based on the above methods. The compositions and results are shown in Tables 4 and 5.

Comparative Example 10
To 100 g of the polymerizable monomer M2, 0.3% by mass of CQ, 1.0% by mass of DMBE, and 0.15% by mass of HQME were added and mixed to obtain a uniform polymerizable monomer composition. Was prepared. Next, the inorganic spherical filler shown in Table 4 was measured in a mortar, the polymerizable monomer composition was gradually added under red light, and 0.070 g of titanium dioxide (white pigment) was further added. 0.002 g of yellow (yellow pigment), 0.0006 g of pigment red (red pigment), and 0.0002 g of pigment blue (blue pigment) were added and sufficiently kneaded in a dark place to obtain a uniform curable paste. The paste was further defoamed under reduced pressure to remove air bubbles, thereby producing a dental composite restoration material. The color tone (equivalent to A4) conforming to the A system of the high chromaticity model teeth was visually evaluated. Subsequently, each physical property was evaluated based on the above methods. The compositions and results are shown in Tables 4 and 5.

  As can be understood from the results of Examples 1 to 17, when the conditions defined in the present invention are satisfied, the dental curable composition shows yellow to red colored light due to light interference under a black background, It can be seen that the color tone compatibility is good and high bending strength is exhibited.

  As understood from the results of Comparative Examples 1 and 2, when only inorganic spherical fillers having an average particle diameter of 230 or 280 nm were blended as fillers, yellow and red colored light due to light interference under a black background was clear. However, because the contrast ratio of the cured product is low, good color tone compatibility cannot be obtained for class IV cavities.

  As understood from the results of Comparative Example 3, when only the inorganic spherical filler having an average particle diameter of 178 nm was blended as the filler, the colored light due to light interference under a black background was blue, and the contrast of the cured product was high. Due to the low ratio, good color compatibility with class IV cavities cannot be obtained.

  As understood from the results of Comparative Examples 4 to 9, if the conditions specified in the present invention are not satisfied, the dental curable composition does not show colored light under a black background (Comparative Examples 4 to 8 It can be seen that the shape is irregular), the colored light is weak (Comparative Example 9: the average particle size of the irregular inorganic filler does not satisfy 100 nm to 1000 nm), and the color tone compatibility is poor.

  As can be understood from the results of Comparative Example 10, the dental curable composition in which the color tone was adjusted by adding a pigment (the color tone (equivalent to A4) conforming to the system A of the high chromaticity model tooth) was measured using a color difference meter ( (Tokyo Denshoku Co., Ltd., “TC-1800MKII”) was used to measure the spectral reflectance of the background color black and the background color white. An indication was observed. The color tone compatibility with a color tone (equivalent to A4) conforming to the A system of the high chromaticity model teeth was relatively good, but the color tone compatibility with other model teeth was low.

Claims (7)

The polymerizable monomer component (A) has an average primary particle diameter in a range of 100 nm or more and 1000 nm or less, and 90% or more of all particles in a number-based particle size distribution is in a range of 5% before and after the average primary particle diameter. The inorganic spherical filler (B), an amorphous inorganic filler (C) having an average particle diameter in the range of 100 nm or more and 1000 nm or less and a polymerization initiator (D). A curable composition for dental use, wherein the refractive index at 25 ° C .: n _FB is larger than the refractive index at 25 ° C .: n _P of a polymer obtained by polymerizing the polymerizable monomer component (A). object. In a spectral reflectance curve under a black background measured with a color difference meter for a cured body having a thickness of 1 mm, the maximum value of the spectral reflectance in the wavelength region of 600 nm or more and 750 nm or less: SR ₁ is set to 400 nm or more and 500 nm or less. To give a cured product having a spectral reflectance ratio: SR ₁ / SR _{2 in} the range of 0.8 to 2.0, which is defined as a value obtained by dividing the maximum value of the spectral reflectance in the wavelength region of: SR _2. The dental curable composition according to claim 1, characterized in that:   The total blending amount of the inorganic spherical filler (B) and the amorphous inorganic filler (C) is 100 parts by mass or more and 1500 parts by mass or less based on 100 parts by mass of the polymerizable monomer (A). 3. The dental curable composition according to claim 1, wherein a proportion of the compounded amount of the amorphous inorganic filler (C) in the composition is 5% or more and 50% or less. 4. The cured product of thickness 1 mm, both when the husband the Y stimulus value determined by tristimulus values measured by the color difference meter was the background with black and white s Y _{b (black} background), and Y _{w (white} background) ratio: Y b _/ Y contrast ratio defined by _w which is characterized in that a cured body is 0.3 to 0.7, dental curable composition according to any one of claims 1 to 3 .   The dental curable composition according to any one of claims 1 to 4, wherein the inorganic spherical filler (B) has an average primary particle diameter of 230 nm or more and 350 nm or less.   A dental filling and restorative material for repairing a class III cavity and / or a class IV cavity, comprising the dental curable composition according to any one of claims 1 to 5.   A dental material for a class III cavity and / or a class IV cavity restoration, comprising a cured product of the dental curable composition according to any one of claims 1 to 6.