Objective: The aim of our study is to compare the ability of two nickel-titanium systems that use different rotation motions to create preparations that could promote a complete filling of the apical third of root canals.
Methods: We used 36 freshly extracted teeth, randomly divided in two groups, as follows: in Group A we used ProTaper Next, a system characterized by a continuous rotary motion and in Group B the teeth were instrumented with Wave-One, in which the files have a reciprocating motion. All teeth were root filled based on the same protocol, using gutta-percha and AH Plus. The teeth were further prepared for microleakage evaluation based on dye penetration technique, as follows: immersion in 2% methylene blue, longitudinally sectioned and examination of the apical thirds with an operating microscope. The distance of dye penetration along dentin walls was measured using the ImageJ program.
Results: The comparison between rotational and reciprocating systems showed that reciprocating files significantly promoted a reduced apical microleakage, as demonstrated by unpaired t test, Welch corrected (p=0.0346).
Conclusion: The use of Wave-One Reciprocating system was considered more effective in the shaping of root canals, as they demonstrating better conditions for the hermetic, tridimensional sealing of apical third of the roots canals.