Er:YAG laser irradiation versus conventional surface treatments: a pull-out bond strength study on glass fiber posts

This in vitro study aimed to investigate the influence of Er:YAG laser irradiation on the retention of glass fiber posts by comparing its effect on pull-out bond strength with conventional chemical and mechanical surface treatment methods. One hundred extracted human maxillary central incisors were endodontically treated and prepared to receive glass fiber posts. The specimens were randomly allocated into five groups (n = 20) according to the post surface treatment protocol: no treatment (control), aluminum oxide sandblasting, Er:YAG laser irradiation, hydrofluoric acid etching, and silane application. All posts were cemented using a dual-cure resin cement. Pull-out bond strength was measured using a universal testing machine, and the obtained data were statistically analyzed using one-way ANOVA and Tukey post hoc tests (α = 0.05). Pairwise comparisons revealed that both hydrofluoric acid etching and sandblasting resulted in significantly higher bond strength values compared with the control, laser, and silane groups (p < 0.001 for all relevant comparisons). Additionally, the laser group demonstrated significantly lower bond strength values than both the acid and sandblasting groups (p < 0.001), while no significant difference was observed between the laser and silane groups (p > 0.05). Within the limitations of this in vitro study, Er:YAG laser irradiation did not enhance the pull-out bond strength of glass fiber posts. In contrast, hydrofluoric acid etching and aluminum oxide sandblasting demonstrated superior bonding performance and resulted in significantly higher retention values. These findings suggest that, under the tested parameters, Er:YAG laser irradiation did not demonstrate a significant improvement in the pull-out bond strength of glass fiber posts. Conventional chemical and mechanical surface treatment methods, particularly hydrofluoric acid etching and aluminum oxide sandblasting, showed more favorable bonding performance under the tested conditions.