Comparative antimicrobial activity of an essential oil and an amine fluoride stannous fluoride mouthrinse in vitro

Although laboratory studies are not necessarily predictive of clinical activity, they can help to elucidate mechanisms underlying clinical activity when the latter has been established. In a recent clinical study, an essential oil mouthrinse (Listerine(R) Antiseptic) was shown to be significantly more effective than an amine fluoride/stannous fluoride mouthrinse (Meridol(R)) in inhibiting supragingival plaque formation. This paper reports the results of laboratory studies comparing the antimicrobial effectiveness of these 2 mouthrinses using a kill kinetics assay and a plaque biofilm kill assay In both assays, the essential oil mouthrinse was considerably more effective than the amine fluoride/stannous fluoride mouthrinse. These findings are consistent with the results of the clinical trial and may help to explain the observed differences in clinical activity.