Comparative evaluation of silver nanoparticles and 5.25% sodium hypochlorite for rapid chairside decontamination of artificially infected gutta-percha with Escherichia coli: An In vitro Study

Introduction: The aim of this in vitro study was to evaluate the efficacy of 50 ug/ml silver nanoparticle (AgNPs), 70 ug/ml AgNPs and 5.25% sodium hypochlorite (NaOCl) as a final irrigant for rapid chair-side decontamination of artificially infected gutta-percha (GP) with Escherichia coli. Materials and Methods: A series 120 GP cones size 40 were taken from new batch. The GP cones were divided into six experimental group: Group I - Evaluation of the contamination of GP cones in manufacturer's Box-(20 GP cones), Group II - Evaluation of GP artificially contaminated with E. coli (100 GP cones), Group III - Evaluation of the effectiveness of 50 ug/ml of AgNPs for decontamination of the cones contaminated with E. coli ( n = 20 GP infected cones from Group II), Group IV - Evaluation of the effectiveness of 70 ug/ml of AgNPs for decontamination of the cones contaminated with E. coli ( n = 20 GP infected cones from Group II), Group V - Evaluation of the effectiveness of 5.25% NaOCl for decontamination of the cones contaminated with E. coli ( n = 20 GP cones infected from Group II). Aliquots from the experimental GP cones were plated on brain heart infusion agar (HiMedia Lab, Mumbai, India), and the colony-forming units were evaluated under colonimeter. Results: 70 ug/ml of AgNPs, 5.25% NaOCl exhibited similar antimicrobial effect ( P = 1). Highly significant difference were found when 50 ug/ml compared with 70 ug/ml and 5.25% NaOCl ( P Conclusion: 70 ug/ml of AgNPs (0.007%) proved to be highly effective against E. coli and showed similar antimicrobial efficacy as 5.25% NaOCl at 750 times lesser concentration.