Dental caries and caries-associated microorganisms in the saliva and plaque of 3- and 4-year-old Afro-caribbean and Caucasian children in South London

Three and four-year-old Caucasian and Afro-Caribbean children (n = 641) attending childcare facilities in the London boroughs of Lambeth, Lewisham and Southwark were studied in order to determine the prevalence of caries and caries-associated micro-organisms and the interactions between these for each of the racial groups; dmft (decayed, missing or filled teeth) scores were recorded using British Association for the Study of Community Dentistry criteria. Saliva and plaque samples were taken from each child and the numbers of mutans streptococci, lactobacilli and yeasts per sample were determined. The mean dmft scores of the 3- and 4-year-old Afro-Caribbean children were 0.36 ± 0.10 and 0.51 ± 0.13, respectively, compared to 0.80 ± 0.17 and 1.48 ± 0.24 for the equivalent Caucasian children (p < 0.001). Mutans streptococci and lactobacilli were recovered less frequently from the Afro-Caribbean children than from the Caucasian, but in both groups there were significant correlations between the plaque and salivary levels of mutans streptococci and caries experience. In both groups, children from whom both mutans streptococci and lactobacilli were isolated had the greatest mean dmft scores and these were not significantly different. Multiple regression analyses demonstrated that, after controlling for age and dmft, there were still significant associations between race and salivary levels of mutans streptococci and lactobacilli, p = 0.0013 and p = 0.0167, respectively. These data indicate that Afro-Caribbean children had lower levels of dental caries than Caucasian children living in the same London boroughs and attending the same preschool care facilities and, after controlling for age and caries experience, they also had lower salivary levels of mutans streptococci and lactobacilli.