Method: Thin vestibular canals of thirty maxillary molars, with angles of curvature between 25 and 35 degrees have been used. The sample was divide in three grups arbitrary of ten canals each, all of them were instrumented with Endo-Mate NSK engine with torque and speed control, using the crown-down technique untills a size of #30 work length. Using a radiographic platform, reproducible preinstrumentation and postinstrumentation radiographs were taken. The radiographs was digitalized, then through a NIH Image J system were performed a total of 12 measures from radiographic vertice canals. Data were analized using statistic test non-parametric Mann-Whitney and kruskal Wallis for independent sample.
Results: ProTaper Universal system produces statistically significant transportation, also presents the greatest percentage of transpotation. RaCe and Hero Shaper does not present significal statistically transportation.
Conclusions: The results suggest that ProTaper Universal system produces transportation in the middle third and apical of canal, however RaCe and Hero Shaper system proved to be recommended, in mechanical terms, in the middle third and apical of curved canals.