Assessment of the Antibacterial Activity of Calcium Hydroxide Combined with Chlorhexidine Paste and Other Intracanal Medications against Bacterial Pathogens

OBJECTIVES: The purpose of this study was to assess the in vitro antibacterial activity of four formulations of calcium hydroxide [Ca(OH)(2)] pastes against Enterococcus faecalis, Staphylococcus aureus, Pseudomonas aeruginosa and Streptococcus mutans. METHODS: A broth dilution test was performed, and the lengths of time for different pastes to kill the microbial cells were recorded and statistically analyzed. The following medications were assessed: Group I – Ca(OH)(2) + 2.0% chlorhexidine (CHX) gel; Group II – Ca(OH)(2) + camphorated paramonochlorophenol (CMCP) and propylene glycol; Group III – Ca(OH)(2) + propylene glycol; Group IV – Ca(OH)(2) + saline. RESULTS: The results showed that E. faecalis was the most resistant microorganism. Groups II and III eliminated all the microbial cells in 15 seconds. Group I took 45 seconds to eliminate E. faecalis. CONCLUSIONS: Under the conditions of this study, it was concluded that all the intracanal medications tested showed antibacterial activity. However, the association of Ca(OH)(2) and PMCC or Ca(OH)(2) and propylene glycol showed a better performance, since Groups II and III took a shorter length of time than the other groups to eliminate S. aureus and E. faecalis.