The plaque- and gingivitis-inhibiting capacity of a commercially available essential oil product. A parallel, split-mouth, single blind, randomized, placebo-controlled clinical study.

Background: Studies have reported commercially available essential oils with convincing plaque and gingivitis preventing properties. However, no tests have compared these essential oils, i.e. Listerine(®), against their true vehicle controls.

Objective: To compare the plaque and gingivitis inhibiting effect of a commercially-available essential oil (Listerine(®) Total Care) to a negative (22% hydro-alcohol solution) and a positive (0.2% chlorhexidine (CHX)) control in an experimental gingivitis model.

Materials And Methods: In three groups of 15 healthy volunteers, experimental gingivitis was induced and monitored over 21 days, simultaneously treated with Listerine(®) Total Care (test), 22% hydro-alcohol solution (negative control) and 0.2% chlorhexidine solution (positive control), respectively. The upper right quadrant of each individual received mouthwash only, whereas the upper left quadrant was subject to both rinses and mechanical oral hygiene. Plaque, gingivitis and side-effects were assessed at day 7, 14 and 21.

Results: After 21 days, the chlorhexidine group showed significantly lower average plaque and gingivitis scores than the Listerine(®) and alcohol groups, whereas there was little difference between the two latter.

Conclusion: Listerine(®) Total Care had no statistically significant effect on plaque formation as compared to its vehicle control.