Van Swaaij BWM, et al. - Via searching MEDLINE-PubMed and Cochrane-Central up to October 2018, researchers ascertained if chlorhexidine mouthwash (CHX-MW), with an anti-discoloration system (ADS), is effective in preventing extrinsic tooth surface discoloration, as well as assessed if CHX combined with an ADS maintains its effectiveness with respect to decreasing plaque and gingivitis scores. Descriptive analysis showed that the majority revealed no differences in bleeding, gingivitis and plaque scores. According to this systematic review and meta-analysis, non-brushing studies show moderate-quality evidence that adding ADS to CHX-MW reduces the discoloration of the tooth surface and does not appear to affect its properties with respect to gingival inflammation and plaque scores. There is also moderate evidence of quality in brushing studies that ADS does not affect CHX's anti-plaque and anti-gingivitis effectiveness. Most comparisons, including meta-analysis, show no important impact of ADS on tooth staining in cases where mouthwash is used in addition to toothbrushing.