The following study found that chlorhexidine inhibited plaque growth significantly more than the mouthrinse containing chlorine dioxide Chlorine dioxide and chlorhexidine mouthrinses compared in a 3-day plaque accumulation model (J Periodontol. 2008 Aug;79(8):1395-400).

BACKGROUND
The aim of this study was to investigate the inhibiting
effect of a chlorine  dioxide mouthrinse as opposed to a mouthrinse containing chlorhexidine (0.20%) during 3 days of plaque accumulation.
METHODS: At baseline, all participants (N=77) received a professional prophylaxis and were randomly assigned to the test (chlorine dioxide) or (positive) control (chlorhexidine) group.
On the following 3 days, both groups rinsed twice daily for 1 minute with 10 ml test or control solution. At the end of the experimental period, plaque was assessed, and the
panelists filled out a questionnaire.
RESULTS
Chlorhexidine inhibited plaque growth significantly more than the mouthrinse containing chlorine dioxide (plaque index=1.39 versus 1.96, respectively; P<0.001). The results of the questionnaire showed that the panelists
found chlorhexidine easier to use and more effective. However, they preferred the taste of the chlorine dioxide mouthrinse and experienced less taste alterations.
CONCLUSION
Chlorine dioxide mouthrinse seems to be a less potent plaq
ue inhibitor than
chlorhexidine. PMID: 18672988