Objectives: To evaluate Cavit? G, ProRoot? MTA and Tetric® EvoFlow as intraorifice barriers to prevent coronal microleakage in root canal treatment. Study Design: Forty-two human single rooted teeth were divided randomly in three experimental groups of 10 specimens each and two control groups. The experimental groups were prepared with hand instrumentation and cold lateral condensed technique of the gutta-percha. Four millimetres of coronal gutta-percha were removed and replaced by one of the following filling materials: Cavit? G, Tetric® EvoFlow or ProRoot? MTA. In the experimental groups, leakage was measured by the concentration of leaked glucose in the apical reservoir at 1, 7, 30, and 45 days, using the enzymatic glucose oxidase method. Data were analyzed by means of Mann-Whitney U and Kruskal-Wallis tests at ?=0.05. Results: The glucose penetration results of three experimental groups increased gradually over time. No significant differences were found among groups at 24 hours and 1 week. At thirty and forty-five days, Cavit? and Tetric® EvoFlow values were significantly different (p=0.007 and p=0.023, respectively). Conclusions: The sealing ability of the Cavit? G, ProRoot? MTA and Tetric® EvoFlow used as intraorifice materials tends to be similar over time.