Antimicrobial activity of chlorhexidine and calcium hydroxide gels: an in vitro evaluation

Objective: The aim of this study was to determine in vitro the antimicrobial activity of calcium hydroxide and chlorhexidine gels against various microorganisms. Methods: The diffusion methodon double layer Müller-Hinton agar (MH) was employed and five wells were made at equidistant points. The substances were placed into the wells and the microorganisms Enterococcus faecalis,Candida albicans, Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa were seeded by pour plate. Results: The gels of calcium hydroxide and chlorhexidine presented antimicrobial activity against all m icroorganisms. Association of both substances was more effective against Enterococcus faecalis and Candida albicans, when compared to calcium hydroxide gel alone, although this association produced halos withsmaller diameters when compared to chlorhexidine gel used alone. Conclusions: The tested substances were effective against all microorganisms; larger inhibition halos were observed against Enterococcus faecalis and Candida albicans; the present methodology did not allow observation of a synergistic effect of this association.