Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Breath odour
RCT 4-armed trial	99 people	Mean odour score change from baseline (assessed on a scale from 0 [no halitosis] to 5 [offensive halitosis]) at 4 weeks –0.41 with mouthwash containing cetylpyridinium chloride (used twice-daily) +0.06 with chlorine dioxide plus zinc mouthwash (used twice-daily) 0 with essential oil mouthwash	P value (among the 3 treatment groups) reported as not significant 4 people were excluded or withdrew after randomisation Analysis not by intention-to-treat		Not significant
RCT 3-armed trial	48 people	Organoleptic breath scores 4 weeks with regular-use mouthwash containing zinc chloride plus sodium chlorite with regular-use mouthwash containing zinc chloride only Absolute results reported graphically	Reported as significant for zinc chloride plus sodium chlorite mouthwash v zinc chloride alone mouthwash P value not reported	Effect size not calculated	regular-use mouthwash containing zinc chloride plus sodium chlorite
RCT 4-armed trial	174 people	Mean odour score change from baseline day 21 with amine fluoride/stannous fluoride, zinc lactate, oral malodour counteractives mouthwash with chlorhexidine, cetylpyridinium chloride, and zinc lactate mouthwash with chlorhexidine mouthwash Absolute results reported graphically	Reported as not significant		Not significant
RCT	22 people	Proportion of individuals with organoleptic scores 1 or less 1 week 64% with chlorine dioxide mouthwash plus tongue scraping 81% with chlorhexidine gluconate mouthwash plus tongue scraping Absolute numbers not reported	Reported as not significant		Not significant