PROBLEM TO BE SOLVED: To provide a filler and a method of preparing the same having an excellent abrasive property and optical characteristics such as surface lubricative property or the like required for a dental composition and capable of concurrently imparting an excellent abrasion resistance, durability, mechanical strength or the like.SOLUTION: This inorganic filler is obtained by coating polyorganosiloxane to the surface of fine inorganic particles having average particle size of 0.01-5 &mum. The method of preparing the inorganic filler includes (1) a wet grinding process fine grinding raw material inorganic particles into fine inorganic particles having average particle size of 0.01-5 &mum or a wet dispersing process cracking agglomerates of inorganic particles comprising primary particles having average particle size of 0.01-5 &mum into the primary particles and (2) a process forming a film of polyorganosiloxane on the surface of the obtained inorganic fine particles. The invention includes a dental composition including the inorganic filler.COPYRIGHT: (C)2002,JPO【課題】 歯科用組成物に要求される優れた研磨性および表面滑沢性等の光学的特性を有し、且つ優れた耐摩耗性、耐久性および機械的強度等を共に付与することのできる充填材およびその製造方法を提供する。【解決手段】 平均粒子径が0.01~5μmの無機微粒子の表面がポリオルガノシロキサンで被覆された無機フィラー。(1)原料無機粒子を平均粒子径0.01~5μmの無機微粒子に微粉砕する湿式粉砕工程、または1次粒子が平均粒子径0.01~5μmであり、かつ凝集した無機微粒子凝集体を1次粒子に解砕させる湿式分散工程および(2)得られた無機微粒子の表面にポリオルガノシロキサン皮膜を形成する工程、を含む上記無機フィラーの製造方法。上記無機フィラーを含む歯科用組成物。
