Effects of post surface treatments on the bond strength of self-adhesive cements

Purpose: To evaluate whether fiber post surface conditioning techniques would influence the ultimate retentive strength of self-adhesive resin cements into the root canal. Methods: 50 single-rooted premolars with one root canal were endodontically treated and prepared to receive a fiber post. Five groups were formed (n=10) according to the post surface pre-treatment performed: (1) Silane application (Monobond S) for 60 seconds; (2) 10% hydrogen peroxide application for 20 minutes; (3) Rocatec Pre; (4) Silicate/silane coating (DT Light SL Post); (5) No treatment (DT Light Post). Two self-adhesive resin cements (RelyX Unicem and MaxCem) were used as luting agents. The bonded specimens were stored up to 1 month (37 degrees C and 100% humidity). The force required to dislodge the post (MPa) via an apical-coronal direction was measured with the push-out bond strength test (cross-head speed: 0.5 mm/minute until failure). Failure patterns were evaluated under SEM. Data was statistically analyzed with one-way ANOVA and Tukey tests (P< 0.05). Results: No increase in the push-out bond strength values were observed for RelyX Unicem, independently from the post surface treatment performed. MaxCem attained higher bond strengths when luted to silanated posts.