Antimicrobial evaluation of root canal irrigants of natural sources with and without gamma radiation activation - An in vitro study

ABSTRACT Aim: The present study aimed to evaluate the antibacterial effectiveness of newly formulated root canal irrigants derived from natural sources. In particular, this study investigated how these irrigants’ antimicrobial properties were affected by gamma radiation activation. Methods: Fifty-three single-rooted extracted human teeth with straight canals were selected, fully prepared, and sterilized. The roots were then infected with Escherichia coli , Enterococcus faecalis , and Candida albicans for 21 days at 37°C. Based on the irrigating solution utilized, the roots were divided into seven groups: Group I: chitosan irrigant, Group II: chitosan irrigant gamma irradiated, Group III: curcumin irrigant, Group IV: curcumin irrigant gamma irradiated, Group V: sodium hypochlorite (NaOCl) 5% irrigant, Group VI: positive control (infected roots without treatment), and Group VII: negative control (uncontaminated roots). After cleaning and shaping, microbiological sampling was performed. The samples were then transferred to sterile centrifuge tubes containing 1 mL of saline to determine the microbial growth. Colony-forming unit counts were employed for assessing the antimicrobial action. Statistical analysis was conducted to compare the percentage reduction in the microbial count from the initial count. Results: Group V and Group IV showed significantly higher values in microbial reduction than Group III and Group I. In addition, the results showed that Group II and Group III have significantly higher values than Group I. Conclusion: Natural irrigating solutions exposed to gamma radiation exhibited promising antimicrobial activity that is comparable to that of NaOCl and may be used as effective antimicrobial agents in endodontic treatment.