Comparative Analysis of Push-Out Bond Strength Between Prefabricated Solid Glass Fiber Post and Bundled Glass Fiber-Reinforced Resin Post

Background: The objective of this study was to conduct a comparative analysis of the push-out bond strength between a prefabricated solid glass fiber post and a bundled glass fiber-reinforced resin post at the coronal, middle, and apical thirds.

Material and Methods: The crowns of twenty extracted human mandibular premolars were removed to obtain the root length of 17 mm. After canal extension and fillings were completed, two groups were prepared from roots randomly: bundled fiber (Rebilda Post GT-RB) and solid fiber (Reforpost-RF). The canal preparation was made for the Reforpost with its own drill. Posts were cemented into root canals with dual-cure resin cement. The roots were embedded in cylindrical acrylic blocks. Six sections were obtained from a root. A push-out test was applied to the post surface by a universal test machine. The debonding value between the post and dentin surface was recorded in Newton and converted to MPa using the formula.

Results: The push-out bond strength values displayed no significant variance among the post systems across all root thirds (p>0.05). Nonetheless, a notable distinction was noted between the root regions of RF (p=0.032), with the middle third demonstrating higher bond strength values compared to the coronal third. Conversely, for RP, no significant variance was observed between root regions (p>0.05).

Conclusions: Rebilda Post GT showed similar results to those of Reforpost in terms of push-out bond strength between post and root canal dentin. It has not been found to have an advantage over solid fiber posts.