Background: An efficient apical seal is a fundamental aim to achieve endodontic success, also by using simplified shaping and filling techniques. This in vitro study analyzes the microleakage using a non destructive method after 7 and 30 days in extracted teeth, treated following 4 different instrumentation and obturation protocols. Methods and Materials: Forty single-rooted teeth were sectioned at 16 mm from the apex, NaClO disinfected (5,25%) and then divided into 4 groups (n°=10), which were treated as follows: G1, M- Two/GT Obturator (GTO); G2, M-Two/System B (SB); G3, GTX/GTO; G4, GTX/SB. The specimens were stored at 37°C in saline solution. The filtration values (μL/min) were registered by using the fluid filtration technique after 7 and 30 days. The Friedman and Wilcoxon, Kruskal-Wallis and Mann-Whitney tests were used to analyze the collected data (p<0,05). Results: The mean values (±SD) of microinfiltration (μL/min) at the 7th day were: G1=0,14 (±0,05); G2=0,13 (±0,07); G3=0,15 (±0,07); G4=0,14 (±0,05); at the 30th day they were: G1=0,22 (±0,06); G2=0,17 (±0,14); G3=0,16 (±0,06); G4=0,16 (±0,10). Group 1 only showed significant higher filtration values after 30 days. Conclusions: All examined techniques presented limited microleakage values at the 7th day, which did not increase at the 30th day, except in the M-Two/GTO group.
