Analisi attraverso scansione AFM degli effetti superficiali degli irriganti canalari (NaOCl e EDTA) sui Protaper

Objective. The aim of this study was to investigate, by using atomic force microscopy (AFM), the effects of sodium hypochlorite (NaOCl) and EDTA on the surface characteristics of ProTaper rotary nickel titanium instruments. Study design. A total of 20 ProTaper nickel-titanium files ( S1,S2,F1,F2), were divided in 5 groups: no immersion, immersion in 5.25% NaOCl for 5 or 10 minutes and immersion in 17% EDTA gel for 5 or 10 minutes. Twenty areas of the surface along 3-mm section at the tip of the files (perfect squares of 1μm x 1 μm) were analyzed by atomic force microscopy (AFM Perception, Assing, Italy) operating in contact mode under ambient condition. Three-dimensional images (400 × 400 lines) were processed by Gwiddion software and the roughness average (Ra) and the rootmean- square value (Rms) of the scanned surface profiles were recorded. The data were analyzed using Student t Test. Results. Mean Rms and Ra values for NaClO and EDTA measurements were statistically higher than the measurements on new files ( P < 0.05). Conclusion. The AFM results show that NaOCl and EDTA significantly increased the surface roughness of Protaper files.