ABSTRACT
Fluoride occurs naturally in all water supplies at varying concentrations. Water fluoridation may be defined as the adjustment of naturally occurring levels to an optimum within this range for the purposes of prevention of dental decay (dental caries). The level required depends on climate; in temperate countries the required level is most often 1 part per million. The discovery of relatively less dental disease in children living in areas of naturally occurring optimal levels led to the introduction of schemes of artificial fluoridation in 1945.1 The exact mode of action of fluoride in preventing caries is not fully understood but may include the direct effects of fluoride present in the mouth (topical), and, to a lesser extent, of that absorbed through the body (systemic).
