Pre- and post-treatment levels of salivary mutans streptococci and lactobacilli in pre-school children

Objectives. To examine the effect of operative and restorative treatment of dental caries on the levels of caries associated microorganisms in saliva and to relate alterations to the type and extent of treatment. Design. Longitudinal. Setting. Paediatric Dentistry Department at a central hospital in Sweden. Subjects and methods. One hundred and eight pre-school children with severe dental caries scheduled for treatment under general anaesthesia. Chair-side tests were used to estimate the levels of salivary mutans streptococci, lactobacilli and buffer capacity before the surgery and at recall appointments 1 and 6 months after treatment. Caries were assessed according to WHO guidelines and the number of extracted teeth and filled surfaces during surgery were recorded. Results. The results demonstrate that the post-treatment levels of mutans streptococci and lactobacilli were significantly reduced (P < 0.001) compared to pretreatment levels. Lactobacilli levels were more dramatically reduced than mutans streptococci. The reduction of mutans streptococci was positively correlated to the number of extracted teeth (P < 0.01), but not to the number of restored or ground surfaces. Lactobacilli reduction was not significantly related to the type of treatment. Conclusion. The findings suggest that extensive operative and restorative dental care effectively reduces the levels of caries associated with microorganisms during a period of at least 6 months.