Abstract: The present invention provides dental fillers having the optical and/or mechanical characteristics required to dental materials, a method of producing the same, and a dental composite material prepared with use of the dental filler. More specifically, the present invention provides a dental filler containing a zirconium silicate compound, especially a zirconium trisilicate compound with a wadeite type crystalline structure and having an average particle diameter in the range from 2 to 50,000 nm, a method of producing the same, a dental composite material containing the dental filler and a hardenable resin selected from an acrylic resin, a methacrylic resin, an epoxy resin, a vinyl resin, a urethane resin and the like.

Abstract: A dental filler having the optical and/or mechanical properties satisfying the requirements to a dental material, a method for producing the dental filler, and a dental composite material containing the dental filler. The dental filler comprises microparticles of amorphous inorganic oxide constituted by at least silica-based fine particles covered with a composite oxide comprising zirconium, silicon and oxygen. The dental composite material contains the dental filler and a hardenable resin selected from an acrylic resin, a methacrylic resin, an epoxy resin, a vinyl resin and a urethane resin.

Abstract: The hard coat layer-forming composition of this invention includes (A) composite oxide fine particles with a mean particle diameter of 1 to 200 nm, containing titanium, tin and optionally silicon, and with a rutile-type crystal structure, (B) an organosilicon compound represented by the formula R1aR2bSi(OR3)4?(a+b) and/or a hydrolyzate thereof, and (C) a cyanamide derivative compound. A hard coat layer formed from the composition not only is excellent in transparency, scratch resistance, adhesion property, weathering resistance, impact resistance, etc. but also can enjoy no coloration or little coloration, particularly in bluing or yellowing, upon exposure to or irradiation with ultraviolet rays, even if an antireflection film is provided.