Water fluoridation is defined as the addition of industrial-grade fluoride chemicals -- typically hydrofluorosilicic acid or and sodium silicofluoride -- to the water supply, with the goal of helping prevent tooth decay. It's estimated that 70% of the water supply in the United States is fluoridated. This contrasts with most developed nations, including all of Japan and most of Western Europe, which do not have fluoridation programs.
