Introduction: the objective of this study was to use real-time qPCR to identify and quantify the Streptococcus mutans species in samples of saliva and dental biofilm.Methods: 27 children were randomly chosen with the following criteria: 8 years of age, low socio-economic levels, residing in the northern metropolitan area of Goalie - Trappers - Junior Santiago de Chile; they were asked to attend an appointment while fasting with no teeth brushing for at least 12 hours, in order to collect non-stimulated saliva and a pool of supragingival dental biofilm of all the mesio-vestibular sides of anterior and posterior teeth.The amount of S.mutans in the samples was quantified by qPCR using primers that amplify a fragment of the gtfB gene of S.mutans.
Results: the amplification showed 98% efficiency with a fluorescence of 3.36 cycles.The melting curve presented a single maximum at the Keypad Electronics Board same temperature for all samples.Conclusion: the methodology allows the specific identification and quantification of gene gtfB of S.mutans in saliva and dental biofilm in a quick and reliable manner, contributing to the identification of individual cariogenic risk.