This study compared bacterial leakage in root canals filled with Resilon/Epiphany when the post-space was prepared immediately versus delayed by 5 days. All samples showed bacterial leakage within 14 days with no significant difference between immediate and delayed post-space preparation. The null hypothesis that the timing of post-space preparation would not affect the apical seal was not rejected. The study concluded that a true monoblock seal was not achieved with Resilon/Epiphany regardless of when post-space preparation occurred.