Caries prevalence in the deciduous dentition of a Tanzanian urban and rural child population in relation to levels of fluoride in drinking water in 1984, 1986 and 1988.

A mixed-longitudinal study to determine the prevalence of caries in the deciduous dentition of a Tanzanian child population was carried out in Morogoro Region between 1984 and 1988. Since 1978 shallow wells have been constructed in the study areas which contained water in the range of the assumed optimal fluoride level in tropical countries (0.5-1.0 ppm). Three areas were distinguished, urban, rural and villages in rural areas with an average fluoride concentration of 0.5 ppm or more in all drinking water sources present. There were no fluoridated toothpaste for sale nor were organised oral health programmes implemented in the study areas. The following background parameters were studied; age, locality, socioeconomic status and sex. School children aged 7- to 9-year (= 694), 7- to 11-year (n = 652) adn 7- to 13-year (n = 555) were examined in 1984, 1986 and 1988 respectively. For all three years of investigation, children living in villages with naturally fluoridated water were found to have significantly lower mean number of dentinal lesions than those living in urban and/or rural areas. There were no restorations found. Over the three years of investigation the mean dft*-scores were low and varied between 1.67 (urban area in 1984) and 0.79 (naturally fluoridated rural areas in 1984). No SES and sex effect on the dft-condition were found. It is recommended that water samples be collected from all drinking water sources in all regions of Tanzania and to map the results of the fluoride analyses for use in prioritization setting in planning oral health services at national and regional level.