Disclosed is a preparation for oral cavity that is appropriately usable as a prophylactic agent for dental caries, a therapeutic agent for dental caries in early stage, a prophylactic and/or therapeutic agent for dentinal hypersensitivity, a lining material for dentin cavity, etc., which shows an excellent effect of blocking the dentinal tubules, is capable of improving the acid resistance of the teeth and recalcifying the teeth, ensures a short-time treatment with an easy operation, and has a high safety and good esthetic properties. Specifically disclosed is a preparation for oral cavity such as a prophylactic agent for dental caries and/or a therapeutic agent for dental caries in early stage, a prophylactic and/or therapeutic agent for dentinal hypersensitivity, a lining material for dentin cavity, etc., comprising a liquid (A), in which fluoroaminosilicate glass micrograins are dispersed, and an aqueous inorganic phosphoric acid solution (B).
