Effect of time interval between core preparation and post cementation on pushout bond strength of glass fiber-reinforced posts.

Introduction: The aim of this study was to investigate the effect of timing of coronal preparation on the pushout bond strength of fiber postluted with resin cement in the root canal.

Materials And Methods: In this experimental study, 48 mandibular human premolars were selected in a 3-week range. After root canal treatment and postspace preparation, a post #2(Angelus, Brazil) was cemented into the canal by a resin-based cement (Bifix SE, VOCO, Germany). Cylindrical resin composite cores were built on the posts. Then, the specimens were divided into 4 groups of 12 specimens each: one control group without core preparation and 3 experimental groups with core preparation that was done 15 min, 1 h, and 24 h after postcementation. One day after postcementation, each root was sectioned into 3 segments. Each slice was connected to universal testing machine. The load was applied at the speed of 0.5 mm/min till failure happened. The collected data were analyzed (SPSS/PC 20.0; SPSS Inc., Chicago, IL, USA) using two-way ANOVA and Tukey test at < 0.05 level of significance.

Results: Mean shear bond strength differences among interventional groups were not statistically significant ( > 0.05). Nevertheless, there were significant differences among root regions ( < 0.001).

Conclusion: It was concluded that core preparation and its timing does not affect adversely retention of fiber post and bond strength is higher in the cervical segment.