Effects of a mouthwash with chlorine dioxide on oral malodor and salivary bacteria: a randomized placebo-controlled 7-day trial.
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 only in short duration trials, moreover, no clinical studies have investigated its microbiological efficacies on periodontal and malodorous bacteria. Thus, the aim of this study was to assess the inhibitory effects of a mouthwash containing ClO2 used for 7 days on morning oral malodor and on salivary periodontal and malodorous bacteria.


METHODS
A randomized, double blind, crossover, placebo-controlled trial was conducted among 15 healthy male volunteers, who were divided into 2 groups. Subjects were instructed to rinse with the experimental mouthwash containing ClO2 or the placebo mouthwash, without ClO2, twice per day for 7 days. After a one week washout period, each group then used the opposite mouthwash for 7 days. At baseline and after 7 days, oral malodor was evaluated with Organoleptic measurement (OM), and analyzed the concentrations of hydrogen sulfide (H2S), methyl mercaptan (CH3SH) and dimethyl sulfide ((CH3)2S), the main VSCs of human oral malodor, were assessed by gas chromatography (GC). Clinical outcome variables included plaque and gingival indices, and tongue coating index. The samples of saliva were microbiologically investigated. Quantitative and qualitative analyses were performed using the polymerase chain reaction-Invader method.


CONCLUSIONS
The baseline oral condition in healthy subjects in the 2 groups did not differ significantly. After rinsing with the mouthwash containing ClO2 for 7 days, morning bad breath decreased as measured by the OM and reduced the concentrations of H2S, CH3SH and (CH3)2S measured by GC, were found. Moreover ClO2 mouthwash used over a 7-day period appeared effective in reducing plaque, tongue coating accumulation and the counts of Fusobacterium nucleatum in saliva. Future research is needed to examine long-term effects, as well as effects on periodontal diseases and plaque accumulation in a well-defined sample of halitosis patients and broader population samples.


BACKGROUND
ClinicalTrials.gov NCT00748943.
Department of Oral Health Promotion, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Japan. shinada.ohp@tmd.ac.jp
Kayoko
K
Shinada
Masayuki
M
Ueno
Chisato
C
Konishi
Sachiko
S
Takehara
Sayaka
S
Yokoyama
Takashi
T
Zaitsu
Mari
M
Ohnuki
Fredrick Allan Clive
FA
Wright
Yoko
Y
Kawaguchi
D000328:Adult; D000891:Anti-Infective Agents, Local / Q000008:administration & dosage*; D017606:Chlorine Compounds / Q000008:administration & dosage*; D002849:Chromatography, Gas; D018592:Cross-Over Studies; D004311:Double-Blind Method; D016967:Fusobacterium nucleatum / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D006209:Halitosis / Q000188:drug therapy* / Q000382:microbiology; D006801:Humans; D006862:Hydrogen Sulfide / Q000378:metabolism; D008297:Male; D009067:Mouthwashes / Q000008:administration & dosage*; D009910:Oral Hygiene; D010087:Oxides / Q000008:administration & dosage*; D017060:Patient Satisfaction; D012463:Saliva / Q000382:microbiology*; D013438:Sulfhydryl Compounds / Q000378:metabolism; D013440:Sulfides / Q000378:metabolism; D013997:Time Factors; D014059:Tongue / Q000187:drug effects / Q000382:microbiology; D016896:Treatment Outcome; D055815:Young Adult
D000891:Anti-Infective Agents, Local; D017606:Chlorine Compounds; D009067:Mouthwashes; D010087:Oxides; D013438:Sulfhydryl Compounds; D013440:Sulfides; C005231:methylmercaptan; C025109:chlorine dioxide; C004784:dimethyl sulfide; D006862:Hydrogen Sulfide