Introduction: The present study aims to determine the effect of different post-space final irrigants ethyl-enediaminetetraacetic acid (EDTA), a mixture of Doxycycline citric acid and detergent (MTAD), Riboflavin (RF) and Pineapple peel extract (PPE) on the bond integrity of GFPs bonded to radicular dentin. Materials and methods: Crowns of forty human mandibular premolars teeth were sectioned up to cementoenamel junction CEJ. Root canal treatment was performed. Gates Glidden drills were used to retrieve gutta-percha from the canal. All the specimens were randomly divided into four groups based on the final irrigant used. Group 1 (NaOCl with EDTA), group 2 NaOCl+ MTAD, group 3 NaOCl+RF and group 4 NaOCl+PPE. Cementation of glass fiber posts (GFPs) was performed using self-etch dual-cure resin cement. Sectioning was performed using a slow -speed saw from the coronal, middle, and apical third under constant water irrigation. A universal testing machine was used to assess push-out bond strength (PBS) and failure mode was evaluated using a Stereomicroscope at 40x magnification. One-way analysis of variance (ANOVA) and Tukey multiple comparison tests were used for sta-tistical analysis (p = 0.05). Results: Group 4 (2.5% NaOCl+ PPE) displayed the highest PBS at all three root levels (Cervical: 11.22 +/- 0.74 MPa, Middle: 8.99 +/- 0.97 MPa, and Apical: 6.00 +/- 0.88 MPa). However, Group 1 (2.5% NaOCl+17% EDTA) demonstrated the lowest EBS (Cervical: 9.25 +/- 0.17 MPa, Middle: 7.01 +/- 1.84 MPa, and Apical: 4.41 +/- 0.17 MPa). Inter-group comparison displayed that PBS to be comparable between group 1 and group 3 (2.5% NaOCl+ Riboflavin) (Cervical: 9.74 & PLUSMN; 0.41 MPa, Middle: 7.44 +/- 1.18 MPa, and Apical: 4.21 +/- 0.05 MPa) (p > 0.05). Whereas, group 2 (1.3% NaOCl+ MTAD) (Cervical: 9.32 & PLUSMN; 1.36 MPa, Middle: 7.17 +/- 1.75 MPa, and Apical: 4.85 & PLUSMN; 0.19 MPa) and group 4 demonstrated comparable values of PBS (p > 0.05). Conclusion: Pineapple peel extract and a mixture of Doxycycline citric acid and a detergent when used as a final irrigant demonstrated better bond integrity of GFPs to radicular dentin at all three levels coronal, middle and apical.
