In this study, the influence of different irrigant solutions applied before cementation on the bond strength (BS) of glass fiber posts to root dentin was evaluated. Thirty endodontically treated maxillary canines of similar length were selected and divided into 3 groups (n = 10) according to the irrigant solution used before post cementation: 1% sodium hypochlorite (NaOCl; control), 2% chlorhexidine (CHX), or a 6.5% grape seed extract (GSE) cross-linking agent. After cementation of the posts, the roots were transversely sectioned to create 2 discs (2 mm) for each of the root thirds: coronal, middle, and apical. These discs were submitted to push-out tests (0.5 mm/min) to evaluate the BS between the glass fiber posts and the root dentin. Statistical analysis was performed by a 2-way analysis of variance and a Tukey test (P < 0.05). The failure mode was evaluated in all specimens. Both the CHX and GSE groups presented significantly higher BS values than the control group in all root thirds (P < 0.05). The values of the GSE group were significantly higher than those of the CHX group in all thirds except the apical third (P < 0.05). In the control group, the BS value was highest in the cervical third. There was no significant difference in the BS values between the cervical and middle thirds when CHX was used (P > 0.05); however, the BS value diminished significantly in the apical third (P < 0.05). The highest BS value in the GSE group was found in the middle third. The results showed that the use of either GSE or CHX before adhesive cementation improved the BS of glass fiber posts to root dentin.
Keywords: chlorhexidine; fiber post; proanthocyanidins; push-out bond strength.