In March 2017 researchers from the UK and Ireland published their review of the medical scientific literature to assess the effect of chlorhexidine mouthwash on gingivitis and plaque. A total of 51 studies involving 5,345 children and adults with gingivitis who had used chlorhexidine mouthwash in addition to toothbrushing, with or without the use of dental floss or interdental cleaning, for at least 4 weeks were included in the review. Results of the analysis showed high quality evidence that chlorhexidine mouthwash reduced mild gingival inflammation when compared to placebo, or no mouthwash after 4-6 weeks of use and at 6 months, However, this was not thought to be clinically significant. Unfortunately, there was insufficient evidence to determine the reduction in gingivitis associated with chlorhexidine mouthwash use in individuals with moderate or severe levels of gingival inflammation. There was, however, high-quality evidence that chlorhexidine mouthwash produced a large reduction in dental plaque when used in addition to toothbrushing, with or without the use of dental floss or interdental cleaning, at 4-6 weeks and 6 months. There was no evidence that one concentration of chlorhexidine was more effective than another or that the frequency of rinsing also had any effect. Rinsing with chlorhexidine mouthwash for 4 weeks or longer appeared to cause tooth staining. In addition, some individuals experienced calculus build up, transient taste disturbance and effects on the oral mucosa with chlorhexidine use.
James P et al. Chlorhexidine mouthrinse as an adjunctive treatment for gingival health. Cochrane Database Syst Rev. 2017 Mar 31;3:CD008676.