Patterns of tooth vulnerability to caries in South African high school pupils.

Caries prevalence and distributions were studied in 761 South African high school pupils aged 17 years in four ethnic groups, living in urban (low F) and rural (low and high F) areas. Mean DMFT values were significantly higher among White pupils than all other groups. Comparison of mean DMFT among the Black pupils showed that urban Black dwellers had a significantly higher score than rural pupils when caries-free individuals were included in the analysis, but not when scores for only those with a DMFT of 1 or more were compared. No significant differences were found between the DMFT values of Black rural pupils living in high or low fluoride areas. Among Black rural pupils, dental caries was approximately three times more common in permanent second molars compared with permanent first molars. In urbanized Black, Coloured, Indian and White subjects, the molars were approximately equally affected.