Does curing delay affect the bond strength of fiber post with self-adhesive cements?

Purpose: To evaluate the effect of three different curing protocols based on different ratios between self-curing and light-curing periods on the bond strength and nanoleakage of fiber posts luted with dual-curing self-adhesive cements. Materials and methods: A total of 48 single-root teeth were endodontically treated and obturated, and an 8-mm post space was prepared with dedicated drills. Specimens were randomly divided into two groups according to the self-adhesive cement employed: G1 = PANAVIA SA Plus (Kuraray Noritake); and G2 = Bifix SE (VOCO). The specimens were further divided into three subgroups (n = 8 each) according to the light curing protocol applied: no light curing (SG1); 20 seconds of light-curing 20 seconds after cement injection (SG2); and 20 seconds of light-curing 120 seconds after cement injection (SG3). Slices of 1-mm thickness were prepared to perform the push-out test and nanoleakage analyses of the coronal and apical regions after 24 hours of storage in artificial saliva. Results were statistically analyzed with three-way ANOVA and Tukey post hoc tests. Statistical significance was set for P < .05. Results: Three-way ANOVA analysis showed that the factors cement (P = .02) and curing protocol (P < .001) had a significant influence on bond strength. Tukey post hoc test reported that light curing 120 seconds after injection showed higher bond strength compared to no light curing and photoactivation after 20 seconds. Conclusion: To achieve the highest bond strength with self-adhesive cements, photoactivation with a 120-second delay after mixing is required. Nevertheless, there is no difference if the time elapsed before applying the light is 20 seconds or if there is no light curing at all.