Aim: The study aimed to investigate the bond strength of epoxy resin-based sealer following five different calcium hydroxide paste removal methods in oval-shaped root canals.
Materials and methods: Sixty single-rooted human mandibular premolars having an oval-shaped root canal as evidenced by radiographs were decoronated and instrumented to size 40/0.04, medicated with calcium hydroxide paste for 7 days, before being randomly assigned to the conventional needle irrigation (CNI), manual dynamic agitation (MDA), sonic irrigation (SI), passive ultrasonic irrigation (PUI), and XP-endo Finisher (XP) groups to be irrigated using different irrigation systems. All specimens were then obturated using an epoxy resin-based root canal sealer and warm vertical compaction obturation technique. After 7 days, each specimen was sectioned into 1 mm root slices at the coronal, middle, and apical third of the root canal and tested for the push-out bond strength using a universal testing machine.
Results: The XP group was the only group that had comparable bond strength to the control group at every level of the root canal following removal of calcium hydroxide medicament (p >0.05). The control group had higher bond strength than the CNI group at every level of the root canal (p < 0.05).
Conclusion: Calcium hydroxide interfered with the bonding of epoxy resin-based sealer to root canal walls. Irrigation with the XP increased the bonding sealer at every level of the root canal.
Clinical significance: The XP was efficacious as a final rinse agitation technique to promote the bonding of the epoxy resin-based sealer at every level of the root canal following calcium hydroxide medication.
Keywords: AH plus; Calcium hydroxide; Irrigation Push-out bond strength..