Effect of Zinc Chloride Containing Mouthwash on Volatile Sulfur Compounds

Objective: To study the effect of zinc chloride containing mouthwash on hydrogen sulfide and methyl mercaptan in the mouth breath. Methods: Double-blind randomized controlled crossover design was used. Twenty six subjects (6 male, 20 female, mean age: 37.2, range: 21-60 y) who met selection criteria and had baseline of oral hydrogen disulfide and methyl mercaptan 120-800 ppb were recruited. All oral hygiene activities were prohibited 24 h before testing. In the morning of the test day, the subjects refrained from eating and drinking, the baselines of both gases were analyzed with Oral Chroma simplified gas chromatography. Subjects were randomly assigned to have either a zinc chloride containing mouthwash (Bright and Clean Listerine) or a control (water) with one week washout period. The subjects rinsed 15 ml mouthwash solution for 30 seconds, and the oral gases were measured at 15, 30, 60 and 120 min after rinsing. The percentage reduction of gas from baseline was analyzed by student t-test. Results: The test mouthwash significantly reduced (p < 0.05) both hydrogen disulfide and methyl mercaptan at all tested time points. At 15, 30, 60 and 120 min, the reductions of hydrogen disulfide and methyl mercaptan were 2.42, 2.10; 23.48, 0.48; 2.02, 0.17 and 0.45, 0.06 folds of control, respectively. Conclusion: Zinc chloride containing mouthwash can be used in the reduction of oral malodor.