An oral antiplaque composition for treatment of teeth wherein the essential antiplaque agent is a substantially water insoluble noncationic antibacterial phenol containing, relative to the hydroxyl group, an alkyl or cycloalkyl group, preferably tert.-butyl (t-butyl), in the 2-position, and substituents in one or both of the 4- and 5-positions, one or both of which may be alkyl or cycloalkyl, one being preferably t-butyl.