The Effect of Chlorhexidine Mouthwash, With or Without Alcohol, on Plaque and Gingivitis: A Systematic Review and Meta-Analysis.

Abstract

Aim: This study systematically assessed the available literature on the effect of a chlorhexidine mouthwash without alcohol (CHXalc-) compared to a chlorhexidine mouthwash with alcohol (CHXalc+) on plaque and parameters of gingivitis. Side effects and user appreciation were secondary outcomes.

Materials and methods: MEDLINE-PubMed and Cochrane-CENTRAL databases were searched up to January 2025 to identify eligible studies. Studies evaluating the effect of CHXalc- compared to CHXalc+ were included. A descriptive analysis and, when feasible, a meta-analysis were performed. The risk of bias was assessed, and the body of evidence was evaluated using the GRADE approach.

Results: After screening, 17 papers met the inclusion criteria and were included. A descriptive analysis demonstrated that most studies showed no differences in plaque, bleeding, and gingivitis scores between CHXalc- and CHXalc+. In non-brushing studies, the overall meta-analysis of plaque scores showed a significant difference in favour of CHXalc+ on end (SMD = 0.49; 95% CI [0.03; 0.95], p = 0.04) and incremental difference scores (SMD = 0.82; 95% CI [0.40; 1.24], p = 0.0001). For brushing studies, the overall meta-analysis showed no significant differences in plaque scores. Further meta-analyses of bleeding and gingival index scores showed, in majority, no significant differences between CHXalc- and CHXalc+. Tooth surface discoloration scores also did not differ. Taste preference was divided, with half of the comparisons with outcomes in favour of CHXalc- and the other half showing no difference.

Conclusion: When a CHX-mouthwash is used in non-brushing situations, there is weak evidence that CHXalc- provided a reduced effect regarding plaque control than CHXalc+. In brushing situations, there is weak evidence for no difference between CHXalc- and CHXalc+ in terms of plaque control. Regarding parameters of gingival inflammation and side effects, there is weak to moderate evidence indicating no difference between CHXalc- and CHXalc+. Regarding user perception of taste, no clear preference emerged from the eligible papers.