Discuss the rationale and scientific basis for the continued use of water fluoridation in communities where caries risk has declined due to the ‘halo effect’ of other fluoride sources.

Artificial fluoridation of communal water supplies has been implemented for over half a century. Since the pioneer fluoridation program in Grand Rapids, Michigan, there has been an increasing assemblage of epidemiological evidence demonstrating and supporting the benefits imparted by water fluoridation.