Socio-economic inequities in dental caries experience of 12-year-old South Africans: policy implications for prevention.

OBJECTIVES: To examine the socioeconomic inequities in dental caries experience of 12-year-olds, in order to inform policy actions for caries prevention in South Africa. METHODS: Secondary analysis of the 1999-2002 national survey data of 12-year-olds (N=5411), available from 37 regions in 7 of the 9 provinces, was carried out. Logistic regression was used to determine risks for caries experience among 12-year-olds in each province, using parental occupation and racial group as independent variables. Regression curve-estimation was used to examine the spatial relationship between mean DMFT and caries prevalence. RESULTS: The mean DMFT (+/-SD) for the study population was 1.19 (+/-2.13), significant caries index was 3.35 and caries prevalence was 40.1%. The highest mean DMFT was among the Coloured population (2.14+/-2.50). Compared to children in the highest occupational class, the risk for children of the unemployed to experience caries was lower in the North West province (Odds ratio [OR]=0.47; p<0.01), but significantly higher in the coastal provinces-- KwaZulu-Natal and Northern Cape, with OR of 1.32 and 1.52 respectively. The regression curve derived demonstrated that a unit increase in caries experience in low-level caries populations would generate more cases than similar increase in high-level caries populations. CONCLUSIONS: DMFT alone provided an incomplete picture of the impact of caries in South Africa, thus the need to monitor inequities as part of policy impact. The distribution of caries suggests that 'high-risk' approach to prevention in the presence of existing social gaps may inadvertently reinforce inequities in caries-burden and supports the concurrent implementation of population-approach, such as water fluoridation.