Micropush-out dentine bond strength of a new gutta-percha and niobium phosphate glass composite

Aim To characterize an experimental gutta‐percha and niobium phosphate glass composite (GNB) applied with a thermoplastic technique to the root canals without sealer in a moist environment and to evaluate its micropush‐out bond strength to root canal wall dentine. Methodology The root canals of sixty human mandibular pre‐molars were prepared using rotary NiTi instruments and irrigation with sodium hypochlorite and EDTA. The teeth were then randomly divided into three groups according to the root filling material used: AH plus sealer and gutta‐percha (AH), EndoSequence BC gutta‐percha without sealer (GBC), and GNB without sealer. The root canals were filled with a single cone using warm vertical condensation. Push‐out bond strengths associated with the filling materials in slices from middle root thirds was determined 30 days after root filling. The failure mode was analyzed with SEM. Analysis using EDX and SEM‐EDS was carried out to verify the composition and distribution of the particles of the tested materials. Data were statistically analyzed by one‐way anova and Tukey's test (P 0.05). The GBC group had the lowest mean bond strength (1.34 ± 0.42 MPa), which was significantly different compared with the other groups (P