Antibacterial Effect of Commercial Mouthwashes on Streptococcus mutans: An in vitro study

Abstract

The aim of this study was to compare the antibacterial effect of eight different commercial (MWs) on two Streptococcus mutans (SM) strains by using the agar well diffusion method. Eight commercial MWs were selected, all of them combined several ingredients in different concentrations, the main active ingredients were: Chlorhexidine gluconate, cetylpyridinium chloride, sodium fluoride, zinc lactate, vitamin B5 and super-oxidized water. The SM strains were extracted from Cultiloops® and incubated for 24 hours at 37 °C. The antimicrobial activity was evaluated using the agar well diffusion method. The inhibition zones were measured using an electronic digital caliper. The R© software was used to perform the statistical analysis using Kruskall-Wallis test and Dunn’s multiple comparisons test. Seven commercial formulas demonstrated inhibitory effect over both SM strains. Only the MW containing super-oxidized water did not exhibit antibacterial activity. Higher inhibitory effect was observed in the chlorhexidine gluconate formula (27.38 ± 0.98 mm and 31.52 ± 0.64 mm). No statistically significant differences were observed when comparing formulas containing chlorhexidine gluconate in combination with other active ingredients. Seven MWs showed antibacterial activity except super-oxidized water formula. MWs containing chlorhexidine gluconate demonstrated the best effect against SM. However, no statistically significant differences were found when comparing formulas using exclusively chlorhexidine gluconate or combined with other antiseptics. Future research must be performed, focused on developing new MWs with similar antibacterial effects to chlorhexidine, but free of side effects, particularly in long-term treatments.

The aim of this study was to compare the antibacterial effect of eight different commercial (MWs) on two Streptococcus mutans (SM) strains by using the agar well diffusion method. Eight commercial MWs were selected, all of them combined several ingredients in different concentrations, the main active ingredients were: Chlorhexidine gluconate, cetylpyridinium chloride, sodium fluoride, zinc lactate, vitamin B5 and super-oxidized water. The SM strains were extracted from Cultiloops® and incubated for 24 hours at 37 °C. The antimicrobial activity was evaluated using the agar well diffusion method. The inhibition zones were measured using an electronic digital caliper. The R© software was used to perform the statistical analysis using Kruskall-Wallis test and Dunn’s multiple comparisons test. Seven commercial formulas demonstrated inhibitory effect over both SM strains. Only the MW containing super-oxidized water did not exhibit antibacterial activity. Higher inhibitory effect was observed in the chlorhexidine gluconate formula (27.38 ± 0.98 mm and 31.52 ± 0.64 mm). No statistically significant differences were observed when comparing formulas containing chlorhexidine gluconate in combination with other active ingredients. Seven MWs showed antibacterial activity except super-oxidized water formula. MWs containing chlorhexidine gluconate demonstrated the best effect against SM. However, no statistically significant differences were found when comparing formulas using exclusively chlorhexidine gluconate or combined with other antiseptics. Future research must be performed, focused on developing new MWs with similar antibacterial effects to chlorhexidine, but free of side effects, particularly in long-term treatments.