Effect of an antiseptic mouthrinse on salivary microbiota

To evaluate the effect of rinsing with original formulation Listerine Antiseptic (LA) on the level of viable salivary bacteria for periods up to 1 hour.

In this double-blind, controlled, cross-over study, unstimulated saliva was collected from 25 subjects, serially diluted, and cultured on selective and non-selective media under aerobic and anaerobic conditions. Streptococci, Veillonella sp., and total aerobic and anaerobic flora were enumerated just prior to and 2, 15, 30, and 60 minutes after rinsing for 30 seconds with either 20 ml of LA or a 5% hydroalcohol control rinse.

After the control rinse, total flora cultivated on MM10 agar exhibited a non-significant (P > 0.05) 10%-20% decrease relative to baseline. In contrast, rinsing with LA resulted in a significant (P < 0.05) 60%-65% decrease from baseline in all four microbial groups at 2 minutes; except in the case of Veillonella, the significant decreases were sustained up to 60 minutes. Total Listerine group aerobic, anaerobic and streptococcal counts were significantly lower than placebo (P < 0.05). The significant reduction in salivary bacterial levels seen in the Listerine group for up to 60 minutes suggests that this antiseptic mouthrinse may have use clinically as a pre-procedural rinse to decrease the level of viable microorganisms in aerosols generated during dental procedures.