The effect of nano chitosan and calcium hydroxide intracanal medications on sealer penetration & bond strength in radicular dentin

BACKGROUND: A three-dimensional obturation that provides a fluid tight seal of the root canal system is essential for long-term treatment success. Intracanal medicaments may hinder sealer penetration and/or affect its ability to bond with dentin. This study aimed to evaluate the sealer penetration and push-out bond strength after using Calcium hydroxide and a 2% nano-chitosan gel (CSNPs). METHODOLOGY: , and Group B, 2% CSNPs. After medication placement for 1 week, all canals were sealed with gutta-percha and AH Plus sealer, mixed with 0.1% fluorescent Rhodamine B isothiocyanate. Sealer penetration was evaluated with confocal laser microscopy and then push-out bond strength was measured for both groups. RESULTS: For both groups, push-out bond strength varied significantly across root thirds (p < 0.001), with higher bond strength in the coronal third. The penetration radius values were significantly greater in the CSNPs group at all root levels (p ≤ 0.001). At the same time, no significant differences were found between groups or among root thirds in terms of penetration area ( p > 0.05). CONCLUSIONS: and CSNPs showed comparable push-out bond strength along the root sections, with deeper, more uniform sealer penetration with CSNPs. CLINICAL RELEVANCE: and CSNPs should be guided by treatment objectives as both medicaments give comparable bond strength, while CSNPs offer advantages for deeper and more uniform tubular penetration.