Comparison of the Bond Strength of Circular and Oval-Shaped Fiber-Reinforced Composite Posts in Oval Shaped Canals

Abstract

Background: Fiber reinforced composite resin (FRC) posts are used to restore endodontically treated teeth. Many factors affect the bond strength of posts; however, there is a concern regarding the mismatch between the posts and oval root canals and its effect on posts retention. Aim: To compare the bond strength of circular and oval-shaped fiber-reinforced composite posts in oval shaped canals. Materials and Methods: Forty Five extracted single rooted human premolars with single oval-shaped root canals were decorated, endodontically treated and prepared to receive quartz reinforced composite resin posts, then they were randomly assigned to three groups, the posts in the first group (control) (n=15) were parallel with circular cross section (Match post, RTD, France), the posts in the second group (n=15) were taper with circular cross section (DtLight Illusion post, RTD, France), The posts in the third group were oval shaped (Macro lock oval post, RTD, France). The posts in the three groups were cemented with dual cure resin cement (Permflo DC Composite Luting, Ultra dent, USA). All samples were then stored in 100% relative humidityat at room temperature for 24 hours then pull-out test was performed and data were analyzed using one-way analysis of variance (ANOVA) followed by Bonferonni's post hoc test (a = 0.05). Results: Oval shaped posts showed higher bond strength values than circular posts, whether the circular posts were conical(taper)or parallel (control) (p<0.05).Conclusions: The bond strength of fiber reinforced composite resin posts in oval root canals increased when the posts were oval-shaped.