Effectiveness of polyhexamethylene biguanide, chlorhexidine, and calcium hydroxide intracanal medicament against intraradicular mature polymicrobial biofilm: A microbiological study

AIM: To compare the effectiveness of different intracanal medicaments against polymicrobial biofilm formed by Enterococcus faecalis, Staphylococcus aureus, and Candida albicans. MATERIALS AND METHODS: Eighty mature human roots with intraradicular polymicrobial biofilm were randomly assigned into four groups (n = 20). Intracanal medicaments 0.2% polyhexamethylene biguanide (PHMB), 2% chlorhexidine (CHX), and calcium hydroxide (CH) were applied into the root canals. Collected dentine samples were tested at 7(th), 15(th), and 30(th) day for microbial growth, and the colony-forming units per ml (CFU/ml) were determined. RESULTS: The CFU/ml data were analyzed using unpaired t-test and one-way ANOVA-F comparison test. All medicaments resulted in a significant reduction (P < 0.05) in microbial growth at all time intervals compared to the control group. CHX and PHMB showed a similar reduction in CFU/ml at 7(th) and 15(th) day but significantly more than CH at all time intervals. At 30(th) day, PHMB caused a significantly more reduction in CFU/ml than CHX. CONCLUSIONS: All the three tested intracanal medicaments such as CH, CHX, and PHMB Gel were effective in reducing the microbial count. CH has a limited antimicrobial effect against the polymicrobial biofilm found inside the root canal. 2% CHX gel has a time-dependent antimicrobial effect. PHMB has a superior antimicrobial effect in comparison with CHX and CH.