Abstract: Antimicrobial hydroxyapatite powders containing hydroxyapatite powder and metal ions selected from silver, copper and zinc ions or one or more antimicrobial agents selected from hinokitiol, tannin, lysozyme, protamine and sorbic acid.

Abstract: A fine filling method for dental purposes is characterized in that a powder, a granulate, a solution (suspension) or paste containing hydroxy-apatite with or without an adjuvant is rubbed on the surface of teeth. A fine filler for use in this method is characterized in that a calcification-promoting protein is incorporated in hydroxy-apatite or tetracalcium phosphate.

Abstract: A tooth-decay preventing composition containing hydroxy-apatite and a fluoride, wherein at least one of the hydroxy-apatite and/or fluoride is microencapsulated or coated.

Abstract: A toothbrush includes a bristle portion having implanted bristles and molded from an ion eluting-type ceramic, a conductor extending into the interior of the bristle portion, and a battery to which the conductor is connected. An electric current flows from the user's hand toward the surface of the teeth through the user's body as the teeth are brushed, thereby causing calcium of fluorine ion, which elutes from the ceramic constituting the bristle portion, to be deposited onto and to penetrate the teeth and dental pulpa while tartar is removed from the surface of the teeth by electronic decomposition.