Evaluation of disinfection of gutta-percha cones and their surface changes using different chemical solutions

Context: Disinfection of obturating materials is mandatory for the successful root canal therapy. In literature, various disinfectants have been used to sterilize gutta-percha including sodium hypochlorite (NaOCl). Effectiveness of peracetic acid over NaOCl is documented in literature, but no study to date has shown the effect of peracetic acid disinfection on gutta-percha surface. Aim: This study aims to evaluate and compare the efficacy of 3% NaOCl, 1% peracetic acid, 0.5% octenisept in disinfecting gutta-percha cones and to analyze surface alterations of gutta-percha cones after chemical disinfection. Materials and Methods: One hundred and twenty gutta-percha cones were immersed in bacterial suspensions of Staphylococcus aureus and Escherichia coli for 5 min. Cones were then immersed in 3% NaOCl, 1% peracetic acid, 0.5% octenisept for 1 and 5 min. After disinfection, cones were incubated in Mueller Hinton Broth at 37°C for 7 days. Samples were observed at 24 h interval and those showing turbidity were subcultured. For morphologic evaluation, cones were immersed in disinfecting solutions for 1 and 5 min, dried on a paper pad for 10 min and analyzed under scanning electron microscope. Data was analyzed using Pearson Chi-square test. Results: One percent of peracetic acid was found to be most effective disinfectant. Surface alterations were found in all the groups. Conclusion: The outcome of this study confirmed the efficacy of 1% peracetic acid in the disinfection of gutta-percha cones. Topographic changes caused by peracetic acid should be evaluated further to determine its effect on gutta-percha properties and obturation seal.