This invention, while optical diffusivity and transparency of the hardened material being superior together, is superior even in mechanical strength and the grinding lubricative property, it is something which offers the hardenability constituent for dentistry where at the same time the handleability of the paste is satisfactory. As for this invention, index of refraction after the polymerization 1.52 - 1.58 the polymerizability monomer which is (A), index of refraction 1.43 - 1.50 the inorganic grain which is (B), and index of refraction 1.52 - 1.58 the inorganic grain which is being the hardenability constituent for dentistry which (C) is included, the aforementioned inorganic grain (B), the average primary particle diameter is the cohesion body of the inorganic particulate 2 - 50nm, the aforementioned inorganic grain (B) the loadings 0.1 - 10 weight % are the hardenability constituent for dentistry which is.本発明は、硬化物の光拡散性と透明性とが共に優れつつ、機械的強度及び研磨滑沢性にも優れ、かつペーストの取り扱い性が良好な歯科用硬化性組成物を提供するものである。本発明は、重合後の屈折率が1.52~1.58である重合性単量体(A)、屈折率が1.43~1.50である無機粒子(B)、及び屈折率が1.52~1.58である無機粒子(C)を含む歯科用硬化性組成物であって、前記無機粒子(B)が、平均一次粒子径が2~50nmの無機微粒子の凝集体であり、前記無機粒子(B)の配合量が0.1~10重量%である歯科用硬化性組成物である。
