Effect of different chlorhexidine varnish regimens on mutans streptococci levels in interdental plaque and saliva.

The aim of the present study was to evaluate and compare the effects of an intensive and a monthly mode of antibacterial varnish application on the levels of mutans streptococci (MS) in interdental plaque and whole saliva. Eighty-eight healthy schoolchildren (11-13 years) with high scores of salivary MS were selected by a screening procedure and randomised into two groups, MS were enumerated at all mesial interdental sites of the first permanent molars with the aid of a modified chair-side technique, disclosing a total of 161 sites with moderate or high colonisation levels. The subjects were treated with a 1% chlorhexidine-thymol-containing varnish (Cervitec) either in an intensive mode (IM) with 3 applications within a 2-week period or in a monthly mode (MM) during a 3-month period. The varnish was applied with a miniball burnisher after the teeth had been cleaned interdentally with dental floss and dried with air. Follow-up samples of saliva and plaque from the interdental areas were collected after 1, 3 and 6 months. Both groups exhibited a statistically significant (p > 0.05) reduction of interdental MS after 1 month when compared with baseline. An eliminated MS growth appeared more frequently following the IM compared with the MM. After 3 months, a significant reduction compared with baseline was still found in the IM group but not in the MM group. No reduction was found in either group after 6 months. MS levels in saliva were mainly unaffected at the follow-up samplings, with the exception of a slight reduction in the IM group after 1 month. In conclusion, the results suggest that an intensive mode of chlorhexidine-thymol varnish application is more effective against interdental MS than the monthly mode of application. Bacterial growth should be monitored in a site-specific way, since interdental reductions were not adequately reflected in whole saliva samples.

RCT Entities:   Population Interventions Outcomes