Efficacy of chlorine dioxide mouthwash in reducing oral malodor: A 2-week randomized, double-blind, crossover study

The aim of this clinical trial was to assess the inhibitory effects of a mouthwash containing 0.1% ClO₂ used for 2 weeks on oral malodor, periodontal and salivary parameters, tongue coating, and Gram-negative and Gram-positive bacteria in saliva. Thirty-nine subjects with oral malodor were randomly assigned into two groups. In the first stage, one group was instructed to rinse with the experimental mouthwash (containing 0.1% ClO₂), whereas the other group was instructed to rinse with the control mouthwash (sodium chloride 0.9%) for 2 weeks. After 4 weeks of washing out, in the second stage, each group then used the other mouthwash for 2 weeks. Oral malodor, periodontal status, tongue coating, salivary pH and flow rate, and the amounts of the salivary bacteria Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Porphyromonas gingivalis, Solobacterium moorei, Streptococcus salivarius, Treponema denticola, and Tannerella forsythia were evaluated at baseline and after 2 weeks of mouthwash use. After 12 hr and after 2 weeks, organoleptic scores and the levels of H₂S and CH₃SH were significantly lower in the experimental group compared with those in the control group. After 2 weeks, the experimental mouthwash appeared significantly effective in reducing plaque index, tongue-coating score, and the amounts of F. nucleatum, S. moorei, T. denticola, and T. forsythia in the whole saliva, compared with those at baseline. Mouthwash containing 0.1% ClO₂ is effective in reducing oral malodor, dental plaque, tongue-coating accumulation, and the amounts of F. nucleatum, S. moorei, T. denticola, and T. forsythia in saliva.