Determinants of first and second molar caries in South Africa

Objectives: In order to inform locally relevant caries prevention strategies in South Africa, this study examines determinants of dental caries prevalence in the first and second molars. Methods: Six- (n=5538), 12- (n=5764) and 15-year-old (n=5342) children examined during the National Children's Oral Health Survey (1999-2002) were analysed in an observational cohort study. First and second molar caries were analysed in terms of socio-demographic factors, area-based water fluoride levels and household expenditure on discretionary sugars. Bivariate analysis included chi-square statistics and T-tests. Multiple logistic regression models were constructed to illustrate the independent association between caries in the first and second molars, and socio-demographic factors, sugar consumption, water fluoride levels and prior caries in the three cohorts. Results: Controlling for confounders, caries prevalence in the primary dentition was a risk indicator for first molar caries in the 6- and 12-year-olds, while low water fluoride levels and coloureds (mixed race) contributed towards an increased likelihood of first molar caries in the 12- and 15-year-olds. Sugar consumption increased the likelihood of first molar caries in the 15-year-olds. High water fluoride levels (≥0.6ppm) and coloureds were associated with reduced caries prevalence in the second molars. However, including first molar caries as covariate in the regression model for 12-year-olds, this association with the coloureds lost significance, while caries in the first molars increased the likelihood of caries in the second molars. Conclusion: This study indicates that prior caries experience has a strong association with caries in the molar teeth and should be used as a selection criterion in a fissure sealant placement protocol. Sugar consumption in adolescents, and cultural practices among coloured South Africans, that potentially increase the risk for caries should be targeted through public health programs. Water fluoridation at 0.6ppm may be effective to prevent caries in the first and second molars.