Abstract: A resin block suitable for dental cutting work may include a resin matrix (A) and spherical filler (B) whose average particle size ranges from 230 to 1000 nm. When 10 mm thick and measured with a colorimeter, the lightness (V) is less than 5.0 and the saturation (C) is less than 2.0 in a Munsell color system of colored light on a black background and a white background. When 1 mm thick, the lightness (V) is less than 5.0 and the saturation (C) is 0.05 or more on a black background, but on a white background, the lightness (V) is 6.0 or more and the saturation (C) is less than 2.0 for Munsell colored light. Resin blocks can be used for dental restoration such that dental prostheses produced from the block not using a pigment/dye are compatible with natural teeth color tone, and the color tone compatibility endures.

Abstract: To prevent gelling even during storage for a long time period under high temperature or room temperature, and to achieve rapid curing under a room-temperature condition at the time of photoirradiation, provided are a photocationically curable composition containing a cationically polymerizable monomer and photoacid generators, and being substantially free of a hydrogen ion scavenger, wherein the photoacid generators include: at least one kind of photoacid generator selected from a photoacid generator formed of an ion pair whose anion is a noncoordinating anion, and a photoacid generator formed of a zwitterionic compound whose anionic moiety is a noncoordinating anionic moiety; and at least one kind of photoacid generator selected from a photoacid generator formed of an ion pair whose anion is not a noncoordinating anion and a photoacid generator formed of a zwitterionic compound whose anionic moiety is not a noncoordinating anionic moiety, and a dental curable composition using the same.

Abstract: Provided is a dental curable composition containing: (A) a porous organic-inorganic composite filler which comprises an organic resin component obtained by polymerizing a polymerizable monomer component (a) including at least 50 mass % of a polymerizable monomer having a hydrogen-bonding functional group, and an inorganic component composed of a plurality of inorganic particles; (B) a polymerizable monomer component including at least 10 mass % of a polymerizable monomer having a hydrogen-bonding functional group; and (C) a polymerization initiator, wherein (C) the polymerization initiator comprises, as photopolymerization initiators, (c1) a photosensitizer compound, (c2) a reducing agent, and (c3) a photoacid generator composed of an aryliodonium salt compound, and the content of the aryliodonium salt compound is 0.1-5 parts by mass with respect to 100 parts by mass of the total mass of (B) the polymerizable monomer component.

Abstract: Provided is a curable composition that is for dentistry and that contains: a polymerizable monomer (A); an inorganic filler (B) having an average particle size of 0.1-1 ?m; an organic-inorganic composite filler (C) having an aggregate structure in which inorganic primary particles having an average particle size of 10-1000 nm are bonded together through a resin layer covering the surface of the particles, to form a void having a specific pore volume; and a polymerization initiator (D). In the organic-inorganic composite filler (C), a curved surface-shaped organic-inorganic composite filler (C1) formed of organic-inorganic composite aggregate particles having a curved surface shape, and an amorphous organic-inorganic composite filler (C2) formed of amorphous organic-inorganic composite aggregate particles having an edge portion, are mixed such that C1/(C1+C2) equals 0.2-0.8 in terms of the number of particles having a particle size of 5 ?m or more.

Abstract: Provided is a dental filling and repairing material kit that is for repairing a tooth having a cavity and that includes a first polymerization curable composition (A) for forming a surface exposed layer exposed to a surface after repairing and a second polymerization curable composition (B) for forming a foundation layer to serve as a foundation of the surface exposed layer. The first polymerization curable composition (A) is formed into a cured body that expresses a structure color by dispersion of inorganic spherical particles in a specific dispersion state in a matrix. Regarding the second polymerization curable composition (B), the brightness (V) of colored light when a sample of said composition with a thickness of 1 mm is measured by using a color difference meter under a black background, is not less than 5 in terms of a color measurement value in the Munsell color system.

Abstract: Provided is a composite material which comprises a resin matrix and inorganic particles dispersed therein, wherein the inorganic particles comprise: one or more groups (G-PID) of spherical particles uniform in particle diameter which comprise aggregates of inorganic spherical particles having a specific average primary-particle diameter, have a narrow particle-size-distribution width, and have a lower refractive index than the resin matrix; and a group (G-SFP) of ultrafine particles. The inorganic spherical particles which constitute all the groups of spherical particles uniform in particle diameter contained in the resin matrix have an arrangement structure which is a short-range order structure satisfying a specific requirement. Also provided are a curable composition giving the composite material and a method for producing the curable composition.

Abstract: Provided are a blank for dental cutting having a part to be cut made from a resin material, wherein the resin material includes a composite material in which inorganic particles are dispersed in a resin matrix, the inorganic particles are made from aggregates of inorganic spherical particles having a specific average primary particle diameter, have a narrow particle size distribution, and include one or a plurality of spherical particle groups of the same particle diameter (G-PID) having a refractive index smaller than that of the resin matrix and an ultrafine particle group (G-SFP), and the arrangement structure of all of the inorganic spherical particles constituting the spherical particle groups of the same particle diameter in the resin matrix has a short-range ordered structure that fulfills specific conditions, and a method for producing the same.

Abstract: Provided is a photocurable composition that contains a polymerizable monomer (A), a spherical filler (B) having an average particle size within the range of 230-1000 nm, and a polymerization initiator (C), the photocurable composition being such that: 90% or more of the individual particles that constitute the spherical filler (B) are within a range of ±5% of the average particle size; the polymerizable monomer (A) and the spherical filler (B) satisfy condition (X1) represented by formula (1): nP<nF (where nP represents the refractive index at 25° C. of a polymer obtained by polymerizing the polymerizable monomer (A), and nF represents the refractive index at 25° C. of the spherical filler (B)); and the polymerization initiator (C) includes a photosensitizing compound (C1), a tertiary amine compound (C2), and a photoacid generator (C3).

Abstract: Provided is a composite material which comprises a resin matrix and inorganic particles dispersed therein, wherein the inorganic particles comprise: one or more groups (G-PID) of spherical particles uniform in particle diameter which comprise aggregates of inorganic spherical particles having a specific average primary-particle diameter, have a narrow particle-size-distribution width, and have a lower refractive index than the resin matrix; and a group (G-SFP) of ultrafine particles. The inorganic spherical particles which constitute all the groups of spherical particles uniform in particle diameter contained in the resin matrix have an arrangement structure which is a short-range order structure satisfying a specific requirement. Also provided are a curable composition giving the composite material and a method for producing the curable composition.

Abstract: A photopolymerization initiator including (a) a photosensitizer, (b) a tertiary amine compound and (c) an aryliodonium salt wherein, as the aryliodonium salt (c), there is selected the one that generates an acid having a dissociation constant of not less than ?3.0 in water of 25° C.

Abstract: Provided is a curable composition containing a polymerizable monomer (A), an organic-inorganic composite filler (B), and a polymerization initiator (C), wherein the organic-inorganic composite filler (B) includes an organic resin matrix (b1) and a spherical inorganic filler (b2) having an average primary particle size of 230-1000 nm, 90% or more of the number of individual particles constituting the spherical inorganic filler (b2) are present in a range of 5% greater or less than the average primary particle size, and the curable composition satisfies the following formulas (1) and (2): nP<nFb2??(formula 1) and nMb1<nFb2??(formula 2) In the formulas, nP represents the refractive index of the polymer of the polymerizable monomer (A) at 25° C., nFb2 represents the refractive index of the spherical inorganic filler (b2) at 25° C., and nMb1 represents the refractive index of the organic resin matrix (b1) at 25° C.

Abstract: Provided is a curable composition comprising a polymerizable monomer (A); spherical particles (B) having an average primary-particle diameter in a range of 230 nm to 1,000 nm; and a polymerization initiator (C), in which 90% or more of individual particles constituting the spherical particles (B) lies in a range of ±5% based on the average primary-particle diameter, and the refractive index of the spherical particles (B) is larger than the refractive index of a polymer of the polymerizable monomer (A). When a 1 mm-thick cured product is formed from the curable composition and the Y value (Yb) of the colored light of the cured product on a black background and the Y value (Yw) of the colored light of the cured product on a white background are each measured using a color difference meter, the ratio therebetween, Yb/Yw, being within a range of 0.2 to 0.5.

Abstract: Provided is a method for producing a dental curable composition, the method includes mixing a polymerizable monomer (A); a spherical filler (B) having an average primary particle diameter within a range of 230 nm to 290 nm; a spherical filler (C) having an average primary particle diameter within a range of 100 nm to 500 nm, the spherical filler having an average primary particle diameter different from that of the spherical filler (B); and a polymerization initiator (D), in which 90% or more in number of the individual particles constituting the spherical filler (B) and the spherical filler (C) are present in a range of ±5% from the average primary particle diameter, and the refractive indices of the spherical filler (B) and the spherical filler (C) are larger than the refractive index of a polymer of a polymerizable monomer (A).

Abstract: Disclosed is an organic/inorganic composite filler that contains: inorganic agglomerated particles comprising agglomerations of inorganic primary particles having a mean diameter between 10 and 1000 nm; an organic resin phase that covers the surface of each inorganic primary particle and binds the inorganic primary particles to each other; and intra-agglomerate voids, formed between the organic resin phase covering the surface of each inorganic primary particle, with a pore volume (here, “pore” refers to holes with diameters between 1 and 500 nm) between 0.01 and 0.30 cm3/g as measured by mercury intrusion porosimetry. Also disclosed is a method for manufacturing the above organic/inorganic composite filler.

Abstract: A resin block suitable for dental cutting work may include a resin matrix (A) and spherical filler (B) whose average particle size ranges from 230 to 1000 nm. When 10 mm thick and measured with a colorimeter, the lightness (V) is less than 5.0 and the saturation (C) is less than 2.0 in a Munsell color system of colored light on a black background and a white background. When 1 mm thick, the lightness (V) is less than 5.0 and the saturation (C) is 0.05 or more on a black background, but on a white background, the lightness (V) is 6.0 or more and the saturation (C) is less than 2.0 for Munsell colored light. Resin blocks can be used for dental restoration such that dental prostheses produced from the block not using a pigment/dye are compatible with natural teeth color tone, and the color tone compatibility endures.

Abstract: A photopolymerization initiator including (a) a photosensitizer, (b) a tertiary amine compound and (c) an aryliodonium salt wherein, as the aryliodonium salt (c), there is selected the one that generates an acid having a dissociation constant of not less than ?3.0 in water of 25° C.

Abstract: A photocurable composition is provided, which is characterized by comprising a polymerizable monomer component (A), an inorganic filler component (B) having an average particle diameter of 0.07 ?m or more, an organic-inorganic composite filler component (C) comprising an inorganic filler component (C1) and an organic polymer component (C2) and having an average particle diameter of 0.5 ?m or more, and a photopolymerization initiator (D), wherein the inorganic filler component (B) and the organic-inorganic composite filler component (C) are contained in a total amount of 100 to 1500 parts by mass relative to 100 parts by mass of the polymerizable monomer component (A), and the polymerizable monomer component (A), 90 parts by mass or more of the inorganic filler component (B) and 90 parts by mass or more of the organic-inorganic composite filler component (C) are selected in such a manner that specific requirements can be satisfied.

Abstract: Provided is a curable composition including a polymerizable monomer component (A), a spherical filler (B) having an average particle size within the range of 230-1000 nm, and a polymerization initiator (C), wherein the curable composition is characterized by having a value (V) of less than 5 and a chroma (C) of 0.05 or higher in colorimetric values according to the Munsell Color System in colored light on a black background, and a value (V) of 6 or higher and a chroma (C) of less than 2 in colorimetric values according to the Munsell Color System in colored light on a white background, each of the values (V) and chroma (C) being measured using a color difference meter in a state in which a 1-mm-thick cured article has been formed.

Abstract: Provided is a method for producing a dental curable composition, the method includes mixing a polymerizable monomer (A); a spherical filler (B) having an average primary particle diameter within a range of 230 nm to 290 nm; a spherical filler (C) having an average primary particle diameter within a range of 100 nm to 500 nm, the spherical filler having an average primary particle diameter different from that of the spherical filler (B); and a polymerization initiator (D), in which 90% or more in number of the individual particles constituting the spherical filler (B) and the spherical filler (C) are present in a range of ±5% from the average primary particle diameter, and the refractive indices of the spherical filler (B) and the spherical filler (C) are larger than the refractive index of a polymer of a polymerizable monomer (A).

Abstract: Provided is a curable composition comprising a polymerizable monomer (A); spherical particles (B) having an average primary-particle diameter in a range of 230 nm to 1,000 nm; and a polymerization initiator (C), in which 90% or more of individual particles constituting the spherical particles (B) lies in a range of ±5% based on the average primary-particle diameter, and the refractive index of the spherical particles (B) is larger than the refractive index of a polymer of the polymerizable monomer (A). When a 1 mm-thick cured product is formed from the curable composition and the Y value (Yb) of the colored light of the cured product on a black background and the Y value (Yw) of the colored light of the cured product on a white background are each measured using a color difference meter, the ratio therebetween, Yb/Yw, being within a range of 0.2 to 0.5.