Endodontology (Jan 2020)
Elastic analysis of Gutta percha cones in 50 μg/ml and 80 μg/ml concentration of silver nanoparticles and 5.25% sodium hypochlorite by atomic force microscope: In vitro study
Abstract
Introduction: Gutta percha (GP) should be sterilized and chemical sterilization is the most reliable method, but the surface topographical alteration is observed on GP; hence in this study, comparison and evaluation of the changes in modulus of elasticity of GP cones after disinfecting it with 5.25% sodium hypochlorite (NaOCl) and 50 μg/ml and 80 μg/ml concentration of silver nanoparticles (AgNPs) for three different durations were performed. Materials and Methods: Ninety GP cones (Dentsply) were taken from the same batch and were randomly selected for the study. GP points were cut 3 mm from their tip and affix to a glass base with a rapid-setting cyanoacrylate glue. Then, the samples were divided into three treatment groups: Group 1, Group 2, and Group 3 comparison between 50 μg/ml and 80 μg/ml AgNPs and 5.25% NaOCl in 1, 5, and 10 min. Untreated GP points were used as control. The samples were positioned in the atomic force microscope (AFM). The AFM analyses were performed on 12 different regions located between 1 and 2 mm from the specimen's tip. One-way ANOVA was used for the statistical analysis. Results: Group 1 – root mean square (RMS) value of 50 μg/ml in 1 min is 8.2, in 80 μg/ml is 8.0, and 5.25% is 6.4; Group II – RMS value of 50 μg/ml in 5 min is 7.94, 80 μg/ml is 7.11, and 5.25% is 5.34; Group III – RMS value of 50 μg/ml in 10 min is 6.38, 80 μg/ml is 6.24, and 5.25% is 4.82; and Group IV – untreated GP cones showed RMS value of 8.3. A statistically significant difference was found among groups. Conclusion: NaOCl despite of being the ideal material for GP sterilization showed some flaws when it comes to surface topographical and physical changes. Changes are, A – NaOCl solution at 5.25% would increase the modulus of elasticity and left a numerous pitting on the surface of GP cones and B –where as AgNPs solution at 50 and 80 μg/ml did not significantly affect mechanical properties and surface texture of GP even after 10 min of disinfection exposure. Therefore, AgNPs can be seen as a safe disinfectant.
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