Effect of F18 Bioactive Glass-Treated Gutta-Percha on Interaction with Endodontic Sealers

This study evaluated the effect of F18 bioactive glass applied to gutta-percha by dip-coating or incorporation on surface bioactivity and bond strength to Bio-C Sealer (BCS) and AH Plus (AHP). Gutta-percha discs (n = 3 per group) were dip-coated with F18 bioactive glass at 2.5%, 5%, and 10% by weight and analyzed by SEM and EDS before and after 28 days of immersion in PBS. Uncoated gutta-percha served as the control for analyses. For the tensile bond strength test, twelve specimens per group (n = 12) were prepared using unmodified gutta-percha, 5% F18 dip-coated gutta-percha, or 2% F18-incorporated gutta-percha, each tested with BCS and AHP. Unmodified gutta-percha with each sealer served as the control. Bond strength was measured using a universal testing machine and analyzed by two-way ANOVA and Tukey's test (α = 0.05). After PBS immersion, the 5% and 10% dip-coated groups exhibited more pronounced F18 deposition and the formation of continuous bioactive surface layers, whereas the control group showed no such features. Regarding bond strength, the 5% F18 dip-coated gutta-percha showed higher values with BCS compared to the control (p < 0.05), and the 2% F18-incorporated gutta-percha also increased bond strength to BCS versus the control (p < 0.05). For AHP, 5% dip-coating reduced bond strength compared with the control (p < 0.05), whereas 2% incorporation did not differ (p > 0.05). F18 bioactive glass promoted surface mineralization of gutta-percha and improved its bond strength to Bio-C Sealer, whether applied by dip-coating or incorporation.