Comparative evaluation of cutting efficiency, cyclic fatigue, corrosion resistance, and autoclave cycle effects of three different file systems: An in-vitro micro-CT and metallurgy analysis

Aim: To compare the cutting efficiency, cyclic fatigue, corrosion resistance, and autoclave cycle effects of ProTaper Gold, TruNatomy, and WaveOne Gold file systems. Materials and Methods: Thirty mesiobuccal roots of extracted maxillary first molars were randomly divided into three groups (10 specimens each) for testing cutting efficiency: Groups A, B, and C: ProTaper Gold, TruNatomy-Prime, and WaveOne Gold-Primary, respectively. Root canal instrumentation was carried out in each root accordingly. Specimens' weights were measured and micro-computed tomography was used to scan the samples before and after root canal preparation. For cyclic-fatigue, corrosion-resistance, and autoclave-cycle-effects testing, 30 files were allocated into three groups at random, Groups A, B, and C: ProTaper Gold-F2, TruNatomy-Prime, and WaveOne Gold-Primary (10 specimens each). For cyclic-fatigue testing, the instruments were firmly held in a stainless steel block with an artificial canal without pressure. The time (s) was calculated until fracture. For the corrosion-resistance test, SEM surface-topographical analysis was carried out in response to 5.25% NaOCl, 2% CHX, and 17% EDTA. For evaluation of autoclave cycle effects, SEM surface-topographical analysis was carried out for 1, 5, and 10 autoclave cycles. Data were analyzed statistically using one-way analysis of variance followed by multiple comparisons with Bonferroni's test at P