WHO pathfinder caries survey in Beijing extended with data for prevalence of mutans streptococci.

A pathfinder caries survey was carried out in Beijing, People's Republic of China, using WHO standard methodologies, in order to estimate the trend by comparing the results with the 1981 caries survey, performed in the same area. Simultaneously, the levels of mutans streptococci in the group were estimated in order to define the proportion of children with high and low mutans levels. Twelve-year-old children were randomly selected from schools in five districts within the city limits. Examinations for caries were performed according to 'WHO Oral Health Surveys' by two calibrated examiners. A total of 178 children were examined for caries and 156 of them were randomly selected for saliva sampling of mutans streptococci, using the 'Strip mutans' method. The number of colonies adhering to the strips were compared with a chart, supplied by the manufacturer, and given a score between 0 and 3, indicating low to very high saliva mutans counts, respectively. The results showed a mean DMFT of 1.87 (1.61-0.06-0.20, for decayed, missing and filled teeth respectively); 66.3 per cent of the children were affected. Fourteen per cent had mutans class 0, 28 per cent class 1, 35 per cent class 2 and 23 per cent class 3. The mean DFT, for each mutans class was 0.82, 1.48, 2.09 and 2.69, respectively. The differences were statistically significant (P = 0.0015). In the lowest mutans class, 50 per cent had caries and the mean number of teeth requiring conservative care was 0.68. For the high mutans group, the corresponding values were 72 per cent and 2.11 teeth.(ABSTRACT TRUNCATED AT 250 WORDS)