The effects of chlorhexidine gluconate (0.12%) on the antimicrobial properties of tooth-colored ProRoot mineral trioxide aggregate.

The purpose of this in vitro study was to determine whether the substitution of 0.12% chlorhexidine gluconate for sterile water as a mixing agent would enhance the antimicrobial activity of tooth-colored ProRoot mineral trioxide aggregate (MTA) against Actinomyces odontolyticus (ATCC17982), Fusobacterium nucleatum (ATCC2586), Streptococcus sanguis (ATCC10556), Enterococcus faecalis (ER3/2S), Escherichia coli (SM10lambdapir), Staphylococcus aureus (ATCC6538), Pseudomonas aeruginosa (UME), and Candida albicans (ATCC10261). Two wells of 5-mm diameter were made in triplicate agar plates inoculated with standardized suspensions of each microorganism. MTA (33 mg) mixed with chlorhexidine (12 microl) or sterile water (12 microl) was placed to fill each well. Plates were incubated at 37 degrees C as required for microbial growth. A blinded, independent observer measured zones of inhibition. All MTA samples inhibited microbial growth regardless of mixing agent. MTA/chlorhexidine showed significantly larger zones of inhibition (p < 0.0002, paired t test). In conclusion, substituting 0.12% chlorhexidine gluconate for water enhanced the antimicrobial activity of tooth-colored ProRoot MTA.