ABSTRACT

Objective: This study evaluated the push out bond strength of a bioceramic sealer modified by nano
magnesium hydroxide with different concentrations (NMH).

Methods: NMH was characterized using
transmission electron microscope and X-ray diffraction analysis. Then, added to Ceramoseal HBC by
0.025%, 0.05% and 0.1% in weight. For push out bond strength test; 40 extracted upper central
incisors were collected and prepared for endodontic treatment. The teeth were decronated, their root
canals were mechanically cleaned and shaped then, grouped randomly into four groups according to
the percentages of added nanoparticles. Group Ⅰ: Bioceramic sealer without added nanoparticles.
Group Ⅱ: Bioceramic sealer + 0.025% NMH. Group Ⅲ: Bioceramic sealer + 0.05% NMH. Group Ⅳ:
Bioceramic sealer + 0.1% NMH. Obturation was performed using gutta percha and the tested
materials. Specimens were placed in 100% relative humidity for 7 days for sealer setting. After that,
2mm coronal slices were cut from each root to be tested for push out bond strength by applying a
deponding force through a computer controlled testing machine till bond failure and bond strength
was calculated in MPa. The data were statistically analyzed using One way ANOVA test and Student
t-test.

Results: The results showed that highest mean bond strength value was recorded for group Ⅳ
(9.72 ± 1.66), while the lowest value was recorded for group I (5.97 ± 1.28). Conclusion: Addition of
NMH to bioceramic sealers enhanced their bond strength.