BACKGROUND: It is important to evaluate concurrently the benefit for dental caries and the risk for dental fluorosis from early exposure to fluoride among children.
AIM: To evaluate associations of different levels of exposure to fluoride in early childhood with dental caries and dental fluorosis experience in school children.
METHODS: A Child Dental Health Survey (CDHS) was conducted among school children in the Australian state of New South Wales (NSW) in 2007. Trained and calibrated examination teams conducted oral epidemiologic examinations to assess caries experience as decayed, missing or filled tooth surfaces of the primary and permanent dentitions (dmfs/DMFS) and fluorosis using the Thylstrup & Fejerskov (TF) index on the maxillary central incisors only. A parental questionnaire collected information on residential histories and tap water usage to enable calculation of percentage of 3-year lifetime exposure to fluoride in water. Use of dietary fluoride supplements was also collected. Dental caries and fluorosis experience were compared among groups by levels of exposure to fluoride from water and fluoride supplements in bivariate and multivariable analysis, controlling for socioeconomic factors.
RESULTS: Exposure to different fluoride sources varied in the group of 2611 children aged 8-12 years. Lower household income was significantly associated in both bivariate and multivariable analyses with the greater prevalence and severity of primary tooth caries among 8-10-year-old children and permanent tooth caries among 8-12 year old. Exposure to fluoride in water during the first 3 years of life was associated with both caries and fluorosis experience observed at age 8-12 years. Having higher percentage of 3-year lifetime exposure to fluoride in water was associated with higher prevalence of mostly mild fluorosis, but significantly lower prevalence and severity of caries in the primary and permanent dentitions.
CONCLUSION: There were significant associations of dental caries and fluorosis experience with sources of early childhood fluoride exposure among children aged 8-12 years in New South Wales. Exposure to fluoridated water during the first 3 years of life was associated with better oral health of school-age children.