[Streptococcus mutans: its relation to cariogenic activity].

This research was carried out with the purpose of learning about relationship between degree of infection by Streptococcus mutans in saliva and prevalence of caries and further incidence in a one year term. A total of 931 children aged 2-3 years of Havana City and Sancti Spiritus Province, and 10 different series of school children aged 6-12 years of both provinces, with a total of 848 children, were studied. A direct significant relationship between degree of infection by S. mutans and prevalence of caries (percentage of affected children and co/COPD index) was found in the groups under study. Likewise, in the relationship between previous degree of infection and incidence of caries, differences were significative in children aged 2-3 years and in six of the 10 series of school children, with a correlation (r) of 0.216. It is analyzed that despite that degree of infection by Streptococcus mutans is the parameter with higher correlation with cariogenic activity, its predictive value is not enough by itself, therefore, a joint valuation with other parameters also related to cariogenic activity is required, in order to be able to reach necessary validity in the prognosis.