Fracture load and shear stress of prefabricated glass fiber posts

ABSTRACT

Aim: This study evaluated the fracture load and pattern failure of different prefabricated glass fiber posts (GFPs) of the same diameter. Methods: Seventy-eight (n=13 for six groups) GFPs of 1.6 mm coronal diameter of different brands were evaluated­ Exacto (Angelus), Power Post (BM4), White Post DC (FGM), HiRem (Overfibers), MAQ (Maquira), and SD (Supordont). The posts were subjected to fracture load testing (45° of inclination and 1 mm/min until fracture). Each factor (load (N) and shear stress (MPa)) was analyzed separately using one-way ANOVA followed by the Tukey test (α=0.05). Results: The type of failure was evaluated on a stereomicroscope (×10). The Power Post samples presented higher values of fracture load (p<0.001) followed by Maquira fiber post, White Post , HiRem, Superpost, and the Exacto posts. The failure pattern observed was intralaminar mode II in-plane shear, such as a failure occur parallel to fibers. Conclusion: Despite the same diameter of GFPs, the fracture load and shear resistance were brand-dependent