Short term effect of mechanical plaque control on salivary concentration of S. mutans and lactobacilli

All visible plaque was professionally removed from teeth of 40 children who were highly infected with S. mutans and lactobacilli. Shortly before and after the removal of plaque the concentrations of those bacteria were assessed in saliva stimulated by chewing. S. mutans and lactobacilli correlated well at baseline but not after plaque elimination, e.g. more than 80% of children who were heavily infected with S. mutans could be identified by a lactobacillus test at baseline. After the elimination of plaque, the mean concentration of S. mutans dropped by 64% but lactobacilli remained unchanged. The results indicate that oral hygiene measures taken by the patient prior to sampling of saliva may mask the true concentration of salivary S. mutans and complicate the identification of high caries risk patients.