Charles CH et al. (2000)

IN VIVO ANTIMICROBIAL ACTIVITY OF AN ESSENTIAL OIL-CONTAINING MOUTHRINSE ON INTERPROXIMAL PLAQUE BACTERIA¹

Objective

To determine the in vivo interproximal bactericidal efficacy of LISTERINE^® Antiseptic following toothbrushing.

Methods

This was a randomized, controlled, crossover study involving 34 generally healthy adults aged 23-64 years. Subjects rinsed for 30 seconds with 20 ml of either LISTERINE^® Antiseptic or a sterile water control rinse. Five minutes later, interproximal plaque was collected using paper points, and bacterial counts were quantified using high end point dilution and spectrophotometric methods. After a 48-hour washout period, subjects repeated the procedure with the alternate rinse.

Results

LISTERINE^® Antiseptic significantly reduced total plaque bacteria. There was a 43.8% reduction in recoverable plaque bacteria from interproximal spaces following rinsing with LISTERINE^® Antiseptic compared to control (p< 0.001). This study confirms and expands upon the study by Fine et al (2000), which documented reductions in S. mutans and total streptococci specifically.

Conclusions

These results suggest an antimicrobial mechanism for this mouthrinse in support of the clinically observed reductions in interproximal gingivitis demonstrated in several 6-month clinical trials.

This study suggests that the clinical effectiveness of the essential oil mouthrinse against plaque and gingivitis may be attributable to the rapid kill and plaque permeabilizing properties of the formulation.