ABSTRACT Background The aim of this research was to compare the apical sealing ability of different root-end filling materials (Super EBA®, ProRoot MTA®, thermoplasticized gutta-percha + AHPlus®, thermoplasticized RealSeal®), by means of microbial indicators. Materials and methods Thus, 50 human single-rooted teeth were employed, which were shaped until size 50, retro-prepared with ultrasonic tips and assigned to 4 groups, retro-filled with each material or controls. A platform was employed, which was split in two halves: upper chamber—where the microbial suspension containing the biological indicators was introduced (E. faecalis + S. aureus + P. aeruginosa + B. subtilis + C. albicans); and a lower chamber containing the culture medium brain, heart infusion, where 3 mm of the apical region of teeth were kept immersed. Lectures were made daily for 60 days, using the turbidity of the culture medium as indicative of microbial contamination. Statistical analyses were carried out at 5% level of significance. Results The results showed microbial leakage at least in some specimens in all of the groups. RealSeal® has more microbial leakage, statistically significant, compared to ProRoot® MTA and SuperEBA®. No significant differences were observed when compared ProRoot® MTA and SuperEBA®. The guttapercha + AH Plus results showed no statistically significant differences when compared with the other groups. Conclusions All the tested materials showed microbial leakage. Root-end fillings with Super-EBA or MTA had the lowest bacterial filtration and RealSeal shows highest bacterial filtration. How to cite this article Amezcua O, Gonzalez AC, Borges AH, Bandeca MC, de Araújo Estrela CR, Estrela C. Sealing Ability of Root-end Filling Materials. J Contemp Dent Pract 2015;16(3):210-214.