Objectives: The aim of present study was to evaluate the clinical preventive procedures effect on salivary levels of mutans streptococci in 18 children between 4-9 years, with high caries risk/activity based on clinical/anamnesical informations. Methods: Procedures consisted of buccal hygiene instructions, dietetics orientation, application of antimicrobial agent, fluoride therapy, gross caries removal and temporary filling of carious lesions and avulsion of residual roots. Non-stimulated saliva samples were collected before procedures and after 7,14 and 21 days. Pure aliquotes and, after seriated decimal dilution in PBS were seeded in SB20 modified medium and incubated on aerophilia during 72 hours at 37ºC. After counting of cfu number of mutans group by mL of saliva, characteristics colonies were submitted to biotiping (chemical proves). The results were submitted a statistical analisis with Friedman and Dunn tests. Results: We could observe a significant statistical reduction on salivary counting of mutans streptococci after 7 (p<0,01), 14 (p<0,01) and 21 (p<0,05) days after oral cavity adequacy, no having statistical difference between the periods of 7, 14 and 21 days. It was observed a media reduction, after 21 days, of 64% of reduction for S.mutans and 49% for S.sobrinus. Conclusions: It could be concluded that clinical preventive procedures favoring the reversion of bacteriological caries risk.