Effect of rinsing with an essential oil-containing mouthrinse on subgingival periodontopathogens

Background: Studies have shown that the nature and amount of supragingival plaque can influence the composition of the contiguous subgingival flora. The purpose of this study was to investigate the effect of rinsing with an essential oil antimicrobial mouthrinse on levels of representative subgingival bacteria in subjects with mild to moderate periodontitis. Methods: This controlled study used a randomized, double-masked, 2 × 2 crossover design. After baseline subgingival sampling, 37 qualifying subjects rinsed with the essential oil mouthrinse or a negative control twice daily for 14 days, with a post-treatment sample obtained on day 15. Following a washout period, the procedure was repeated with the alternative rinse. Target organisms enumerated were Porphyromonas gingivalis, Fusobacterium nucleatum, Veillonella sp., and total anaerobes. Intergroup comparisons of post-treatment log-transformed colony forming unit counts were made using analysis of covariance. Results: After 14 days of twice-daily rinsing, the level of each of the target subgingival organisms was significantly lower in the essential oil group than in the control group (P<0.001), with percent reductions ranging from 66.3% to 79.2%. Conclusions: Rinsing with the essential oil antiplaque/antigingivitis mouthrinse can have significant antimicrobial activity against subgingival periodontopathogens. Most likely, the antimicrobial effect was mediated primarily by disruption of the contiguous supragingival plaque by the mouthrinse. Because studies have shown that control of supragingival plaque can influence the onset and/or progression of periodontitis, additional studies on non-prescription antimicrobial oral care products may lead to new regimens for decreasing the burden of periodontal diseases in the population.