Influence of caries-preventive measures in mothers on cariogenic bacteria and caries experience in their children.

Preventive measures, which reduced the salivary level of mutans streptococci in mothers, delayed colonization by these organisms in their children. The preventive programme was discontinued when the children were 3 years old. These children, at the age of 7 years, and their mothers were now examined to determine the effect of the earlier caries-preventive approach. The control mothers had significantly higher levels of salivary mutans streptococci and lactobacilli than the test mothers (p < 0.05). The median level of salivary mutans streptococci was 0.6 x 10(6) c.f.u. (colony-forming units) per ml in the test mothers and 1.3 x 10(6) c.f.u. in the control mothers. The median level of salivary lactobacilli was 10 times higher in control than test mothers (80 x 10(3) and 7 x 10(3) c.f.u. per ml, respectively). Significantly more children of control than test mothers carried mutans streptococci (95 versus 46%) (z-test; p < 0.01). Children of test mothers had lower salivary levels of mutants streptococci and lactobacilli (p < 0.05). Twenty three % of the test children were caries-free, compared with 9% of the control children (z-test; p < 0.01). The mean caries experience of the test children was also significantly lower than that of the control children (defstot 5.2 and 8.6, respectively; p < 0.05). The results show that reduction of the mutans streptococci in the mother during the emergence of the primary teeth in her child has a long-term influence on colonization by these bacteria and the caries experience in the child.