Effect of an essential oil-containing antiseptic mouthrinse on induction of platelet aggregation by oral bacteria in vitro

Background: With an increasing body of data suggesting an association betwe en periodontitis and cardiovascular disease, studies have been conducted to elucidate potential mechanisms by which oral bacteria might exert systemic effects. 2 oral bacteria, Streptococcus sanguis and Porphyromonas gingival is, have been shown to induce platelet aggregation in vitro. This study was conducted to determine the effect of treatment with an essential oil mouth rinse (Listerine(R) Antiseptic) on the platelet-aggregating activity of the se organisms. Method: Bacteria were grown under standard culture conditions. S. sanguis A TCC strain 10556 was exposed for 3 min to the essential oil mouthrinse at e ither full strength or a 1:1 dilution, while P. gingivalis FDC strain 381 w as exposed to the essential oil mouthrinse at a 1:10 dilution. Positive con trol cells were treated with Hanks balanced salt solution (HBSS). Aggregati on was measured using a recording platelet aggregometer. The assay of each organism in its respective mouthrinse dilution(s) or HBSS was repeated 5 ti mes, Results: In all cases, the HBSS-treated organisms induced platelet aggregat ion, with mean(+/-S.E.) lag times of 12.30 (+/-1.36) min and 11.36 (+/-0.58 ) min for P. gingivalis and S. sanguis, respectively. In contrast, treatmen t with the essential oil mouthrinse completely inhibited the platelet aggre gating activity of P. gingivalis and of S. sanguis exposed to the 1:1 mouth rinse dilution in all assays. the aggregating activity of S. sanguis treate d with full-strength mouthrinse was completely inhibited in 4 of 5 assays, and inhibited by 75% in the 5th, for a mean inhibition of 95+/-1.5%. Conclusion: This study provides additional evidence that the essential oil mouth-rinse can interfere with bacterial cell surface-associated activities which may have clinical relevance.