Effect of topical applications of a novel chlorhexidine-thymol varnish formula on mutans streptococci and caries development in occlusal fissures of permanent molars.

OBJECTIVE

To evaluate the effect of a new formula of a chlorhexidine-thymol varnish on mutans streptococci (MS) colonization and fissure caries development.

METHODS

The study group consisted of 58 healthy adolescents (12-17 years old) undergoing orthodontic treatment with fixed appliances. A double-blind split-mouth design was applied, and 116 pairs of molar teeth were randomly assigned to topical varnish applications with either the new Cervitec Plus or its predecessor Cervitec. Both varnishes contained 1% CHX and 1% thymol (CHX/T) as active ingredients, but differed with respect to adhesive properties. The varnishes were applied in the fissures at baseline, and then every sixth week throughout the 48-week study period. Endpoints were MS colonization (CRT test) and occlusal laser fluorescence (LF, DIAGNOdent) recordings carried out regularly during follow-up.

RESULTS

A significant reduction in the levels of MS in the fissures after the initial treatment was displayed with both varnishes (p < 0.05), and the levels remained consistently suppressed throughout the follow-up period. A non-significant but clear tendency was noted in favor of the new formula after six and 12 weeks, with fewer teeth harboring high counts (> or = 10(5) CFU) of MS (6w:12% vs. 24%, 12w:16% vs. 26%). No new lesions were registered in any subject, and the mean LF recordings did not change significantly over time in the groups.

CONCLUSION

There were no statistically significant differences between the CHX/T varnishes in terms of bacterial growth and caries prevention. For MS suppression, a tendency towards an initially superior effect was displayed with the new formula.