Previous research has shown the oxidizing properties and microbiological efficacies of chlorine dioxide (ClO2). However, no clinical studies have investigated its microbiological efficacies on periodontal and malodorous bacteria. The aim of this study was to assess the inhibitory effects of a mouthwash containing ClO2 on morning oral malodor and on salivary periodontal and malodorous bacteria using for 7 days.

Background: Previous research has shown the oxidizing properties and microbiological efficacies of chlorine dioxide (ClO2). Its clinical efficacies on oral malodor have been evaluated and reported, however, no clinical studies have investigated its microbiological efficacies on periodontal and malodorous bacteria. The aim of this study was to assess the inhibitory effects of a mouthwash containing ClO2 on morning oral malodor and on salivary periodontal and malodorous bacteria using for 7 days.

Methods: A randomized, double blind, crossover, placebo-controlled clinical trial was conducted among 15 healthy male volunteers, who were divided into 2 groups. In the first test phase, the group 1 subjects (N = 8) were instructed to rinse with the experimental mouthwash containing ClO2 twice per day for 7 days, and those in group 2 (N = 7) to rinse with the control (placebo) mouthwash without ClO2. In the second test, phase after a one week washout period, each group had used the opposite mouthwash for 7 days. At baseline and after 7 days, oral malodor was evaluated with OM, and concentrations of hydrogen sulfide (H2S), methyl mercaptan (CH3SH) and dimethyl sulfide ((CH3)2S), the main VSCs of human oral malodor, were evaluated with GC. Clinical outcome variables included plaque and gingival indices, and the Winkel Tongue Coating Index(WTCI). The samples of saliva were microbiologically investigated.

Outcome variables were compared by t-test and Mann-Whitney test.

Inclusion Criteria:

• Clinical diagnosis of oral malodor

Exclusion Criteria:

• Oral malodor caused by foods