Impact of Bioactivity on Push-Out Bond Strength of AH Plus Bioceramic versus BC Bioceramic Root Canal Sealers

Abstract

This study compared the push-out bond strength and adaptation of the recently developed AH Plus bioceramic (AHP-Bio) root canal sealer with Bioceramic Endosequence (BC) and AH Plus (AHP) sealers when exposed to simulated body fluid for inducing bioactivity. Cross-section discs of 1 mm thick slices from obturated root canals were prepared and either kept dry or immersed in serum for 30 days. All discs were evaluated using scanning electron microscopy (SEM) and then subjected to a push-out test. The failure modes were also determined. The data were statistically analyzed using an ANOVA test at p < 0.05. In both environments, the BC sealer recorded the greatest bond strength, while the AHP-Bio sealer recorded the lowest mean values. However, bond strength was significantly improved after immersion in serum (p < 0.001). The chi-square test and Fisher’s exact test revealed a significant difference in failure mode among the tested groups at p < 0.001. The predominant failure mode was cohesive failure in both bioceramic sealers, with the greatest value for AHP-Bio (70%), and adhesive failure for AHP/gutta-percha (60%, 80%) in both environments. SEM revealed good dentin adaptation of the three sealers, with marked decreases in gaps at the bioceramic/dentin interface after immersion in serum. In conclusion, although BC exhibited greater push-out bond strength than AHP-Bio, the latter achieved good displacement resistance that increased when the sealer was exposed to simulated body fluid (serum).