Effect of mechanical and chemical plaque control measures on oral microflora in schoolchildren.

The incidence of S. sanguis, S. salivarius, S. mutans, total streptococci and lactobacilli was examined in highly caries active 13-14-year-old schoolchildren participating in a prophylactic program. After 1 year of trial, professional toothcleaning once every second week markedly reduced the frequency of gingivitis and the caries increment. Bimonthly topical applications of a 0.5% chlorhexidine gel with or without subsequent rinsing with 2% NFP had no effect on plaque score and gingivitis but tended to reduce the caries activity. No significant changes were found in the groups with regard to the salivary number of total streptococci and S. sanguis. A reduction of the population of S. salivarius, S. mutans and lactobacilli was observed in the chlorhexidine group. In the group where chlorhexidine was combined with MFP, only S. mutans was reduced.