The group mutans streptococci, more predominantly isolated of salivary samples, have been the S. mutans and S. mutans/S. sobrinus. The detection of these microorganisms in students of different socio-economic levels and their relationship with the cariogenic activity of these populations was studied, correlating them with the clinical parameters DMFT, DMFS, dmf and dmfs. Two hundred (200) students belonging to five socio-economic levels were distributed in sub-groups, according to the species of microorganisms identified in their salivaries samples. Of all children analysed, 103 (51.0%) presented only S. mutans in the saliva, 33 (17.0%) the association S. mutans/S. sobrinus, and 64 (32.0%), other group mutans species (individually or in association). The statistic evaluation of the available data related to the number of children with dental caries showed, at first, values of 79.0% (81) e 76.0% (25), respectively, to the sub-groups S. mutans and S. mutans/S. sobrinus, showing a high cariogenic index. For the individuals colonized by S. mutans/S. sobrinus and only S. mutans, means 9.40 and 6.70, were seen respectively, to the dmfs index, suggesting that the association S. mutans/S. sobrinus is potentially more cariogenic than the colonization only by S. mutans.
Streptococcus mutans; Streptococcus sobrinus; Dental caries; Social class
