Oral malodor reduction from a zinc-containing toothpaste

To evaluate the anti-malodor efficacy of toothpaste containing 0.2% zinc sulphate after a single brushing and following extended use.

Two clinical studies of common design but different malodor assessment were carried out. In the first study, volatile sulphur compounds (VSC) were measured with a Halimeter; in the second, breath freshness was assessed by odor judges (organoleptic score). At the start of the study, suitable subjects were assigned at random to either the test toothpaste (containing 0.2% zinc sulphate) or the placebo toothpaste (no zinc), and oral breath assessments were made before and two hours after brushing. The same assessments were repeated after allocated toothpastes had been used twice daily for four weeks. Prior to the before-brushing breath assessment, subjects were asked to refrain from eating/drinking and oral hygiene for 12 hours.

The results at the start and end of the study showed a significant reduction in mean Halimeter scores and a significant improvement in organoleptic scores two hours after brushing for subjects using the test toothpaste with zinc sulphate. In addition, at the end of the study, subjects using the test toothpaste with zinc sulphate had reduced Halimeter scores and improved organoleptic scores 12 hours after the last brushing compared to the placebo group. The differences between the test and placebo values ranged from 16% to 46% and were all statistically significant (p < 0.0001).

Both clinical studies independently support the efficacy of the test toothpaste with 0.2% zinc sulphate in reducing oral malodor after a single brushing, and after four weeks for 12 hours after brushing compared to a toothpaste without zinc ions.