Aim: The aim of this study was to evaluate the cutting efficiency of rotary nickel-titanium (NiTi) instruments K3, NiTi Tee, Profile, and Quantec with taper size 04/25.
Materials and methods: The number of samples was 10 for each group (n = 10). The cutting efficiency was measured by the mass loss from each acrylic resin block after instrumentation of a simulated canal using the Crown-down technique.
Results: The analysis of variance (ANOVA) showed that there was a statistically significant difference among the studied groups. The Tukey's test showed that the acrylic resin blocks prepared with instruments K3 (0.00369 ± 0.00022), NiTi Tee (0.00368 ± 0.00023), and Profile (0.00351 ± 0.00026) presented the greatest mass loss, showing no statistically significant difference among them (P < 0.05). The lowest mass loss was found in the blocks prepared with Quantec instruments (0.00311 ± 0.0003) (P < 0.05).
Conclusions: It could be concluded that the K3, NiTi Tee, and Profile instruments presented a greater cutting efficiency than the Quantec instruments.
Keywords: Cross-section; cutting angle; cutting efficiency; rake angle; rotary instruments NiTi.