The effect of sodium hypochlorite and sterilization on cyclic fatigue resistance of HEAT treated rotary file systems

The aim of this study is to evaluate the effect of sterilization and sodium hypochlorite on cyclic fatigue resistance of differently heat-treated EndoArt Touch Blue and Fanta AFtm Blue Rotary instrument systems in curvature canals. In this study, the effects of 5.25% sodium hypochlorite and sterilization at room temperature (21±1) on the cyclic fatigue resistance of two separate Ni-Ti rotary file systems produced with different heat treatment were compared. A total of 80 files, forty EndoArt Touch Blue(25.06) and forty Fanta Aftm Blue Rotary(25.06) files, were used. All files were used in a dynamic cyclic fatigue test device, in stainless steel artificial canals with a curvature angle of 60° and a radius of 5 mm, until they fractured at room temperature. The length of each fractured piece was measured in mm using a digital caliper, and the number of turns it made until it fractured was calculated. In the normality analysis, according to the Kolmogrov Smirnov test results, it was determined that the distribution was normal in the measurements of fracture seconds, KTS and length of the fractured piece (p>0.05) and it was decided to apply parametric tests. Significant results were analyzed with the Bonferroni post hoc test, and the differences between the groups were examined in detail. In the whole study, statistical significance was accepted as p<0.05. According to the results of this study, the resistance to cyclic fatigue of the EndoArt Touch Blue-Solution group was found to be statistically significantly lower among the EndoArt Touch Blue file groups. EndoArt Touch Blue file system produced with Blue heat treatment has statistically higher cyclic fatigue resistance than Fanta AFtm Blue Rotary file produced with R-Wire heat treatment. When evaluated in general, according to the results of this study, the metallurgy of the alloy, the heat treatment difference applied, the irrigation solution used and the sterilization process affect the cyclic fatigue resistance of the files. Keywords: EndoArt Touch Blue, Fanta AFtm Blue Rotary, Cyclic fatigue, Sodium hypochlorite, Sterilization, Nickel-Titanium.