Effect of an antibacterial varnish on mutans streptococci in plaque from enamel adjacent to orthodontic appliances.

The effect of an antibacterial varnish (Cervitec) on the levels of mutans streptococci in plaque adjacent to bonded orthodontic brackets was evaluated in 18 children using a split-mouth technique with a placebo varnish control. The test varnish contained 1% chlorhexidine and 1% thymol as active ingredients. Both varnishes were applied on four occasions during a 3-month period, and plaque was subsequently collected between 1 week and 6 months after the onset of treatment. All teeth involved in the study were carefully examined and clinically assessed for enamel demineralization prior to onset of the fixed appliances and immediately after debonding. The results showed a more frequent growth of mutans streptococci in the dental plaque collected from placebo-treated quadrants as compared with the test quadrants on all sampling occasions. The proportion of mutans streptococci within the plaque microflora was significantly (p < 0.05-0.01) lower on the test sides than on the opposite sides at the 1-week and 1-month examinations. The incidence of incipient enamel lesions around the brackets and along the gingival margin was generally low, and no differences were found between the test and placebo varnish treated quandrants at the time of debonding. The results suggest that mutans streptococci in plaque from orthodontic patients can be suppressed effectively by topical applications of an antibacterial varnish.