The Effect of the Type of Post Space Irrigation on the Push-Out Bond Strength of Glass Fiber Post (An in vitro Study)
Aim: The study aims to evaluate the effect of different irrigant and ultrasonic activation on the push-out bond strength of glass fiber post to the root dentine.
Materials and Methods: Palatal roots of sixty-four maxillary first molar teeth were sectioned at 14 mm and instrumented with ProTaper Next rotary system up to X4 and obturated with AH Plus sealer and gutta-percha size X4. After post space preparation, the samples were divided into eight groups (n=8) according to the post space irrigation as follow; normal saline (control group), normal saline with ultrasonic activation, 5.25% NaOCl, 5.25% NaOCl with ultrasonic activation, 2% chlorhexidine, 2% chlorhexidine with ultrasonic activation, 17% EDTA and 17% EDTA with ultrasonic activation. RelyX fiber posts were cemented with RelyX U200 cement, the samples were sectioned horizontally, and two slices were obtained from each sample. A push-out test was performed using the Universal testing machine at a speed of 0.5mm/min. The statistical analysis involved One-way ANOVA with post hoc Bonferroni test and Student’s t-test. Results: irrigation protocol significantly affected the bond strength (p < 0.001), EDTA showed the highest bond strength and NaOCl showed the lowest bond strength. Ultrasonic activation did not significantly improve the bond strength (P>0.05). The apical regions have significantly higher bond strength than coronal regions (p < 0.001).
Conclusion: post space irrigation with 17% EDTA significantly improved the bond strength of fiber post to root dentine using self-adhesive cement, while the ultrasonic activation of the irrigant solutions had no effect on the bond strength.