Push-Out Bond Strength of Fiber Post Cemented to Root Canal Dentin Obturated with Calcium Silicate-Based Sealer

Abstract Background: The objective of this study was to evaluate the effect of etching modes of ScotchbondTM Universal Plus adhesive (SUP) and post cementation time on the push-out bond strength (POBS) of a fiber post cemented in root canals obturated with calcium silicate-based sealer (CSS). Methods: Fifty-four teeth were randomly allocated to 6 groups (n=9) based on etching modes: self-etch (SE) or etch-and-rinse (ER); post space preparation (PSP) and cementation time: immediate (Im) or 7-day delayed (De): G1:SE/Im-Im, G2:ER/Im-Im, G3:SE/Im-De, G4:ER/Im-De, G5:SE/De-De, and G6:ER/De-De. The root canals were obturated with CSS and the PSP was performed. The fiber post was cemented using RelyXTM Universal resin cement and SUP according to each group’s design. For the POBS test, 1-mm slices of the coronal, middle, and apical regions were tested using a universal testing machine. The failure mode analysis was determined using a stereomicroscope. The data was analyzed with three-way analysis of variance. Results: No negative effects of etching modes, PSP or cementation time on POBS were detected (p>0.05). Additionally, the root canal region also did not significantly affect the bond strength (p>0.05). Conclusion: No significant differences were observed between the etching modes, post space preparation and cementation time and among root canal regions. However, the highest bond strength was demonstrated in the Im-De groups. Clinical relevance: The different etching modes of adhesive and post cementation time did not affect the bond strength of fiber post in calcium silicate filled-root canal.