Antimicrobial effect of a dental varnish, in vitro

The effects of a polymer based antimicrobial releasing varnish Cervitec were investigated against different gram-positive and gram-negative bacterial strains as well as a yeast using the agar diffusion inhibitory test (ADT-test in vitro). As positive controls a 1% chlorhexidine gel and 1% aqueous solution of thymol and a placebo polymer varnish without active agents were employed. The test experimental varnish containing 1% chlorhexidine and 1% thymol showed antimicrobial activity against all gram-positive and gram-negative microorganisms tested including one Candida strain. The positive controls were similar in effect compared to the test varnish. No antimicrobial effect was observed with the placebo varnish without active ingredients. Toothpicks and dental floss treated with the test varnish showed an antimicrobial effect against S. mutans even after storing in room temperature up to 12 months. The results from this study support earlier laboratory studies that chlorhexidine and thymol diffuse out of the experimental varnish and that the varnish is active against various of oral pathogens. The possibility to use toothpicks or dental floss impregnated with the varnish with the aim to become chemotherapeutically active against periodontal diseases as well as against dental caries, is promising and should be tested in vivo.