Moraes, Sergio Herrero [UNESP]Gonçalves, Marcelo [UNESP]Tanomaru Filho, Mário [UNESP]Bonetti Filho, Idomeo [UNESP]2015-08-062015-08-062012RSBO. Revista Sul-Brasileira de Odontologia, v. 9, n. 2, p. 177-182, 2012.1806-7727http://hdl.handle.net/11449/125626Nickel-titanium rotatory systems should remove dentin during the root canal preparation to promote the enlargement and tapered shape with continuously narrowing towards the apex. Objective: The aim of this study was to analyze the cutting ability of three NiTi rotatory systems (n = 12): ProTaper (group 1), Mtwo (group 2), and K3 (group 3). Material and methods: Thirty six maxillary molar teeth were weighted on an analytical balance before and after the rotatory preparation of the mesio-buccal root canal. Data was statistically analyzed by ANOVA and Tukey s test with a significance level of 5%. Results: The results revealed the following mass differences (g) before and after the root canal preparation: ProTaper (group 1 – 0.0159 ± 0.004), Mtwo (group 2 – 0.0125 ± 0.002), and K3 (group 3 – 0.007 ± 0.003). Conclusion: ProTaper showed the highest cutting ability among the three tested nickel-titanium rotatory systems followed by Mtwo and K3.177-182engEndodonticsInstrumentsRoot canal preparationArtigoAcesso aberto106743715986152726652112985847515309258790184438