Influence of fibreglass post design and lengths on the bond strength

Abstract

Post retention in root canal is an important factor on the clinical success of restorations in endodontically treated teeth. AIM: To evaluate the effect of luting agent, fibreglass post design and lengths on the bond strength of posts. MATERIALS AND METHOD: One hundred eighty single-rooted teeth were root filled and prepared to receive either a parallel-sided and serrated fibreglass post or a tapered and smooth fibreglass post (n=90). The posts were cemented with the following resin cements: dual-cured resin cement (RelyX ARC), self-adhesive resin cement (RelyX Unicem) and a self-cured resin cement (RelyX ARC Luting) (n=30). The posts were luting in different depths: 5.0 mm; 7.5 mm; 10.0 mm (n=10). The posts were submitted to a traction test at a speed of 0.5 mm/min and the bond strength values (MPa) were submitted to anova in a split-plot arrangement and Tukey’s test ( ? < 0.05). RESULTS: The analyses of bond strenght values revealed that post length (depths of luting), resin cement and post design was statistically significant ( ? < 0.05). The highest values of retention were observed in the smooth posts.  No difference of retention values was observed in the posts cemented into 5 or 7.5 mm. The highest values were obtained cementation depth of 10 mm. The RelyX ARC and RelyX Unicem showed the highest values of retention. CONCLUSION: Greater depths of cementing provide greater retention. Dual-cured resin cement and self-adhesives had the highest retention values especially when the post format used is smooth and tapered.