Effect of an essential oil-containing mouth rinse on VSC-producing bacteria on the tongue.

The objective of the present study was to investigate the inhibitory effect of a commercially available essential oil-containing mouth rinse 12 hours after a single rinse and two weeks of twice daily rinsing, on volatile sulphur compounds (VSC) producing bacteria on the tongue. The study was a randomized, double-blind, controlled crossover design. Thirty-six healthy subjects, aged 20-48 years, volunteered to participate in the study. Subjects were randomly assigned to rinse twice daily with either an essential oil-containing mouth rinse (Cool Mint Listerine Antiseptic) or a negative control rinse. Bacteria samples were taken from the dorsum of the tongue at baseline, after the first rinse and two weeks later. They were plated on OOPS medium to enumerate the VSC-producing bacteria. Intergroup comparisons of log10 transformed colony-forming units of the samples were made using analysis of covariance. Each comparison was performed at a 5% significance level. The mean VSC-producing bacteria in subjects using the essential oil mouth rinse were significantly lower than those using the control rinse twice daily. In healthy subjects, rinsing with an essential oil-containing mouth rinse can have a significant effect on VSC-producing bacteria on the tongue and may be useful for controlling intrinsic oral malodor over prolonged periods.