A comparison of the effects of different concentrations of fluoride in the drinking water in different parts of Port Elizabeth and Despatch: a first report.

Since April 1993 a part of Port Elizabeth and the surrounding areas have been receiving water from the Orange river, containing on average 0.62 ppm fluoride, while the rest is still receiving water which contains < 0.1 ppm. During August 1994 a survey was done to determine whether the increased levels of fluoride in the Orange river water influenced the caries experience of school children using it. Schools in high, middle and low socio-economic areas in both areas were randomly identified and a random sample of 6-, 12- and 15-year-old children from these schools were examined for caries experience, using the 1987 WHO methodology and criteria for the diagnosis. Results of the survey show that the caries experience in the permanent dentition of 12- and 15-year-old children respectively are 14.0 per cent and 7.8 per cent less in the areas receiving Orange river water, while in the primary dentition at age 6 it is 17.2 per cent higher. This study shows that after only 16 months the use of fluoride containing water may have benefitted the permanent dentition of 12- and 15-year-old children. However the primary dentition of 6-year-old children showed a negative effect.