ASSOCIATIONS BETWEEN EXPOSURE TO FLUORIDATED DRINKING-WATER AND DENTAL-CARIES EXPERIENCE AMONG CHILDREN IN 2 AUSTRALIAN STATES

Objectives: This study assessed associations between exposure to fluor ide in water and dental caries experience among children in two Austra lian states. Methods: Cross-sectional data were obtained from 9,690 So uth Australian children aged 5-15 years and 10,195 Queensland children aged 5-12 years. School dental service practitioners recorded DMFS an d dmfs data. A questionnaire to parents gained information about resid ential history that was used to calculate children's percent of lifeti me exposed to fluoridated water. Results: Greater exposure to fluoride in water was associated with lower dmfs and DMFS in both states (P<.0 1), although in South Australia the effect for DMFS was statistically significant only after controlling for extent of unknown fluoridation exposure and for fluoride supplements Caries-fluoridation associations were stronger for dmfs compared with DMFS and for Queensland (5% of p opulation fluoridated) compared with South Australia (70% of populatio n fluoridated). Effects for DMFS persisted after controlling for socio economic factors. Conclusions: Fluoridation was associated with lower caries experience. The weaker association with DMFS in South Australia may be due to less caries and more fissure sealants in that state, an d is consistent with a ''diffusion'' effect, whereby a high proportion of the population exposed to fluoridation diminishes differences amon g exposure groups.