A preliminary comparison of the effect of 0.3% versus 0.2% chlorhexidine mouth rinse on de novo plaque formation: a monocentre randomized double-blind crossover trial

Objective: Chlorhexidine (CHX) is considered the gold standard against gram-negative microorganisms. Little has been written about the simultaneous influence that both time and concentration could have on antiplaque formation effectiveness of CHX. The aim of this study is to compare the clinical and microbiological effectiveness of two different CHX concentrations and time applications in a 4-day plaque regrowth study model. Material and methods: Twenty volunteers were enrolled in a randomized double-blind crossover study comparing the effectiveness of CHX 0.3% and CHX 0.2% mouth rinses applied for 15 and 30 s, respectively. Plaque index (PII), total bacterial counts and the detection of specific periopathogens were measured at the 5th day of each mouth rinse application. Taste acceptance was evaluated using a questionnaire. Results: Chlorhexidine 0.3% resulted in a statistically greater reductions (10%) in PIl and periopathogens compared to CHX 0.2%. Furthermore, patients reported comparable taste acceptance in both groups. Conclusion: Chlorhexidine is an effective oral antiseptic. The CHX 0.3% mouth rinse formulation used for 15 s resulted in superior clinical and microbiological outcomes compared to the CHX 0.2% formulation, used for 30 s.