Validation of Gas Chromatography Method to Assess Oral Malodor

Objectives: The purpose of this in vivo study was to validate a Gas Chromatography (GC) method to detect differences in Volatile Sulfur Compounds (VSCs) by evaluating the effectiveness of a marketed antiseptic mouthwash to reduce oral malodor relative to a distilled water control.
Methods:
This was a randomized, controlled, parallel-group clinical trial to compare the total Volatile Sulfur Compounds (VSCs) as measured by GC after a 30 second treatment with Listerine Cool Mint Antiseptic Mouthwash or a distilled water control. Generally healthy and consented adult volunteers who fulfilled all inclusion/exclusion criteria with a minimum baseline mean hydrogen sulfide (H2S) reading of ≥ 100 parts per billion (ppb) were enrolled (n=13) in the study. Qualified subjects were randomized and supervised with their assigned mouth rinse. Breath samples were collected and injected into the GC at baseline, immediately after treatment and 60 minutes following their assigned rinse treatment. Analysis of Covariance (ANCOVA) and t-tests were utilized to compare the between- and within-treatment average differences at each time point. All statistical tests were two-tailed and employed a 0.05 level of significance.
Results: Thirteen qualified subjects were randomized to treatment and completed the study. The within-treatment t-tests indicated no statistically significant change from baseline for the water control. For the mouthwash, a significant within-treatment difference was indicated at the immediate time point at p<0.05 and at p<0.06 for the 1-hour time point. The between treatment analysis indicated a statistically significant difference between treatments at p<0.05 at the 1-hour time point and at p<0.6 at the immediate time point.
Conclusions: Considering the relatively small sample size, the validation study to confirm gas chromatography methodology to detect VSC reductions from breath samples resulted in good differentiation at sequential time periods between test products.