Inhibitory effect of benzethonium and zinc chloride mouthrinses on human dental plaque and gingivitis.

In a double-blind study the plaque- and gingivitis-inhibiting capacities of three aqueous mouthrinse solutions of benzethonium chloride, zinc chloride, and benzethonium chloride combined with zinc chloride were compared to those of a placebo mouthrinse. Forth-three adults with clean teeth and healthy gingiva were randomly assigned to the treatment and control groups. All participants received an initial prophylaxis. Assessments of plaque and gingivitis were made before and after a 10-day test period. During this time the subjects suspended oral hygiene procedures and rinsed daily with 20 ml of their respective rinse solutions. According to the measurements made before and after the test period, the mouthrinse containing benzethonium chloride produced 42 to 42.9% less plaque than any of the other three formulations. The differences were statistically significant ( P smaller than 0.05). Gingivitis scores of the four groups did not differ significantly. These findings indicate that benzethonium chloride is a moderately effective antiplaque agent.