Sealers play an important role in the success of root canal treatment. The efficacy of root canal sealer is enhanced by its tubular penetration and adaptation properties.The aim of this study is to evaluate the interfacial adaptation and penetration depth of Bioroot RCS and MTA Plus sealers to root dentin.A total of 60 single-rooted mandibular premolar teeth were prepared using Pro Taper rotary Ni-Ti files and were randomly divided into three groups (n = 20 each) according to the type of sealer used for obturation. After obturation with lateral condensation, half of the samples in each group (n = 10 each) were sectioned transversely for measuring tubular depth penetration under confocal laser scanning microscopy. Longitudinal sections were obtained for remaining half samples to evaluate the adaptation of sealer using scanning electron microscope. Data were analyzed using two-way ANOVA and Tukey post hoc tests.Data were analyzed using two-way ANOVA and Tukey post hoc tests.AH Plus sealer has shown significantly higher depth of penetration and minimum gaps than bioceramic sealers (P < 0.05) MTA Plus sealer exhibited significantly more interfacial gaps and less penetration depth than Bioroot RCS (P < 0.05).At all root regions, AH plus sealer exhibited minimum gaps and more tubular penetration whereas MTA Plus sealer exhibited more gaps and less penetration.