Keywords : Cyclic fatigue
Effect of Irrigating Solutions on Cyclic Fatigue Resistance of Conventional and Heat-Treated Nickel Titanium Pediatric Rotary Instruments: An In-Vitro Study
European Journal of Molecular & Clinical Medicine,
2023, Volume 10, Issue 1, Pages 1206-1218
Background: Introduction of Nickel-titanium (NiTi) alloy files in pediatric endodontics has eased the chemo mechanical preparation. The cyclic fatigue resistance of Niti files is one of the major concerns, which is influenced by various factors including irrigating solutions. So this study aimed to evaluate the effect of irrigating solutions on cyclic fatigue resistance of conventional and heat-treated nickel titanium pediatric rotary instruments.
Methods: 24 Niti rotary files of each: ProTaper Gold; Kedo SG blue and Pro AF Baby Gold were subdivided into (n=12) and immersed in : 1) 3 % NaOCl; 2) 3% NaOCl with 17% EDTA for 10 minutes at 35°C. Cyclic fatigue resistance was assessed by determining number of cycles to fracture (NCF) in a simulated canal and surface changes using scanning electron microscope. Unpaired t-test was applied to compare each treated file with control group, and one-way ANOVA was used for comparison among main groups and Bonferroni post-hoc test for intergroup comparison.
Results: Significant difference in NCF was seen except those between the Pro tapper gold and Pro AF (P>0.05). When 17% NaOCl was used, Kedo SG blue files showed highest fracture resistance (1878.05±66.26). ProTaper Gold (3.94±0.11) showed a significant difference in fractured fragment length.
Conclusion: Exposure of NiTi files to 3% NaOCl and 17 % EDTA affects the cyclic fatigue resistance adversely. Kedo SG Blue files exhibited the best performance among the tested groups.