Efficacy of commercially available chlorhexidine mouthrinses against specific oral microflora

This study evaluates the antimicrobial efficacy of commercially available chlorhexidine (CHX) mouthrinses of different concentrations.

To evaluate and compare the antimicrobial efficacy of commercially available CHX mouthrinses of different concentrations (0.2%, 0.12%, and 0.1%) against specific standard strains of oral microflora at full strength (FS) and 1:1 dilution at 24 h.

Ten commercially available 0.2% (Rexidine, Hexidine, Smilehex, Chlorhex, Hexidale, Hex, Everfresh, and Gargwell), 0.12% (Periogard), and 0.1% (Eludril) CHX mouthrinses were selected to evaluate the efficacy against specific oral microflora using agar well diffusion Method.

The standard strains of Streptococcus mutans American Type Culture Collection (ATCC 21293), Streptococcus sanguis Microbial Type Culture Collection (MTCC 442), Actinomyces viscosus (ATCC 3268), Staphylococcus aureus (ATCC 25923), Streptococcus pyogenes (MTCC 442), and Candida albicans (MTCC 183) were selected. The antimicrobial efficacy was calculated by measuring mean inhibitory zones formed on agar media.

Independent t-test, one-way ANOVA, Kruskal-Wallis tests, and Tukey's Post hoc analysis were used.

Among 0.2% of CHX mouthrinses at FS and 1:1 dilution, hexidine was effective against most of the microorganisms except with S. pyogenes and C. albicans, where Hex and Hexidale were effective, respectively. When the concentration of 0.1% and 0.12% CHX was considered, Eludril was more effective at FS against all except with S. aureus and S. pyogenes which were more sensitive to Periogard at both FS and 1:1 dilution.

0.12% and 0.1% of CHX mouthrinses showed comparable efficacy with 0.2% CHX mouthrinses irrespective of their formulations.