Association of natural fluoride in community water supplies with dental health of children in remote indigenous communities - implications for policy.

OBJECTIVE To map the geographic distribution of fluoride in water supplies and child dental caries in remote Indigenous communities of the Northern Territory (NT). To examine the association between fluoride levels, household and community factors, access to services and child dental caries in these communities and to model the impact on the caries experience of children of introducing water fluoridation. METHODS Fluoride testing was conducted in 80 locations across the NT in 2001. Measures of mean caries experience for six-year-olds and 12-year-olds and community and housing-related infrastructure were obtained from records of the NT School Dental Service. Associations between community fluoride levels, community level variables and childhood caries experience and potential impact of water fluoridation were assessed using linear regression modeling. RESULTS Mean caries experience for six- and 12-year-olds tended to be higher in northern and eastern areas of the NT, corresponding to the distribution of low levels of natural fluoride. Several-fold more children in remote NT communities are exposed to the risks of inadequate fluoride than are exposed to excessive fluoride. Mean reticulated fluoride level was the only variable significantly associated (p<0.05) with caries experience in both age groups. The potential reduction of caries through introducing water fluoridation is expected to be about 28% for children living in communities with the lowest levels of fluoride (<0.3 mg/L). CONCLUSIONS AND IMPLICATIONS Introduction of fluoridation of water supplies into communities with inadequate natural fluoride is a vital measure for improving the dental health of children living in remote NT communities.