Comparative evaluation of push-out bond strength and scanning electron microscopy-based surface morphology of glass fiber posts following various chemical surface treatments: An in vitro study

Abstract

This study aimed to evaluate the influence of different surface treatments on the push-out bond strength (PBS) and surface morphology of glass fiber posts (GFPs) and to assess failure modes. Sixty GFPs were assigned to five groups: Silane; 1.23% acidulated phosphate fluoride (APF) + Silane; 30% hydrogen peroxide (H 2 O 2 ) + Silane; 9.6% hydrofluoric acid (HF) + Silane; and Silane + universal bonding agents. Fifty single-rooted premolars were prepared, obturated, and restored with posts luted using dual-cure resin cement. Three 1-mm sections (coronal, middle, and apical) were obtained for PBS testing. Surface topography and failure modes were evaluated using scanning electron microscopy. Data were analyzed using Analysis of Variance (ANOVA) and Tukey HSD tests. The highest PBS was observed in the 30% H 2 O 2 + silane group, particularly in the cervical region (22.39 ± 0.60 MPa, n = 10), followed by HF + silane (19.63 ± 0.32 MPa) and APF + silane (18.91 ± 0.40 MPa). The silane-only group showed the lowest bond strength (16.61 ± 0.24 MPa). Bond strength decreased significantly from cervical to apical regions across all groups. One-way ANOVA revealed statistically significant differences among all groups ( P < 0.001). Adhesive failure was the predominant mode (68.7%), with no significant difference in failure distribution among groups ( P = 0.673). Thirty percent H 2 O 2 + Silane improved the PBS of GFPs while preserving its surface integrity.