Effect of Dynamic Immersion in Sodium Hypochlorite and EDTA Solutions on Cyclic Fatigue Resistance of WaveOne and WaveOne Gold Reciprocating Nickel-titanium Files

Abstract

Introduction: The purpose of this study was to evaluate the effect of sodium hypochlorite (NaOCl) and EDTA solutions on the cyclic fatigue resistance of WaveOne (WO) and WaveOne Gold (WOG) nickel-titanium reciprocating files. Methods: A hundred WO (25/.08), and 100 WOG (25/.07) were randomly divided into 5 groups: group 1, no immersion; group 2, immersion in 5.25% NaOCI at 37 degrees C +/- 1 degrees C for 5 minutes; group 3, immersion in 5.25% NaOCI at 37 degrees C +/- 1 degrees C for 10 minutes; group 4, immersion in 17% EDTA at 37 degrees C +/- 1 degrees C for 5 minutes; and group 5, immersion in 17 % EDTA at 37 degrees C +/- 1 degrees C for 10 minutes. Then, the instruments were reciprocated in an artificial canal until fracture occurred, and the time to fracture was recorded. The data were statistically analyzed using 1-way analysis of variance and the Student t test via SPSS 21.0 software (IBM Corp, Armonk, NY) with the significance level set at P < .05. Results: The cyclic fatigue resistance of the WOG was statistically higher than the WO in all the conditions tested (P < .05). There was no statistically significant difference among the different conditions tested in terms of cyclic fatigue resistance for both WO and WOG files (P > .05). Among the groups, there was no significant difference in the fracture lengths (P > .05). Conclusions: Within the limitations of the present study, it was determined that NaOCl and EDTA solutions did not have any effect on the cyclic fatigue resistance of WO and WOG files.