Aim. To evaluate the effect of natural antioxidants as final irrigants on the push-out bond strength of epoxy resin-based sealer to the hypochlorite treated dentin.

Methods. Eighty single-rooted human mandibular incisors were prepared using ProTaper Gold (Dentsply, TN, USA) and an irrigation protocol including 3% NaOCl, followed by ethylenediaminetetraacetic acid (EDTA), and 3% NaOCl. The groups (n =20) were divided according to the final irrigant used: Group 1: None (Control); Group 2: 5% sodium ascorbate, Group 3: 5% grape seed extract (GSE); and Group 4: 5% pine bark extract. The obturation of root canals was performed using gutta‑percha and AH Plus (Dentsply DeTrey, Germany). Bond strength was evaluated using the push‑out test under the universal testing machine at a crosshead speed of 0.5 mm/min, and statistical analyses were performed using one-way ANOVA. The p-value significance was evaluated by Tukey’s post hoc test (p<0.01).

Results. Mean push-out bond strength values were compared in all the groups, and there was a statistically significant improvement in the experimental final irrigating groups. 5% pine bark extract had improved bond strength than the other groups, and the least bond strength was observed in the control group.

Conclusion. The irrigation protocols and naturally derived antioxidants affected the resin‑based sealer’s bond strength to root dentin. It was observed that the use of antioxidants effectively reversed the compromised bond strength of resin‑based sealers to root dentin. 5% pine bark extract application showed better bond strength.


antioxidant, epoxy resin-based sealers, grape seed extract, pine bark extract, sodium ascorbate