Objectives: a) To correlate fluoride levels in drinking water sources with caries experience and dental fluorosis in Saudi Arabia, and suggest appropriate fluoride concentration for drinking water in the country.
Methods: Fluoride levels were determined from 3,629 samples obtained from drinking water sources in 11 regions of Saudi Arabia. Based on the fluoride concentrations, a stratified sample of subjects aged 6-7, 12-13, and 15-18 years was obtained from the regions. A total of 12,200 selected subjects were examined for dental caries according to the World Health Organization criteria, and dental fluorosis, using Thylstrup and Fejerskov classification.
Results: There was an inverse relationship between fluoride exposure and caries experience, but the prevalence of dental fluorosis increased with increase in fluoride concentration. There was no significant difference in caries experience or in the prevalence of dental fluorosis when fluoride levels increased from 0.3 ppm to 0.6 ppm. In contrast, caries experience was lower, while severity of fluorosis was significantly higher at fluoride levels above 0.6 ppm.
Conclusions: a) Fluoride levels in drinking water sources in Saudi Arabia correlate significantly with caries experience and prevalence of dental fluorosis. b) Appropriate fluoride concentration for drinking water in Saudi Arabia may be about 0.6 ppm.