Evaluation of the resin cement thicknesses and push-out bond strengths of circular and oval fiber posts in oval-shapes canals

Abstract

Purpose: The aim of this study was to evaluate whether the push-out bond strength varies between oval and circular fiber posts, and to examine the effect on the resin cement thicknesses around the posts.

Materials and methods: Eighteen mandibular premolar roots were separated into two groups for oval and circular fiber posts systems. Post spaces were prepared and fiber posts were luted to the post spaces. Roots were cut horizontally to produce 1-mm-thick specimens. Resin cement thicknesses were determined with a metallographic optical microscope and push-out tests were done.

Results: No significant differences were observed in terms of push-out bond strength between the oval and circular fiber posts (P>.05) The resin cement thicknesses of the oval posts were greater than those of the circular posts group in the coronal, middle and apical specimens (P<.05).

Conclusion: In the light of these results, it can be stated that resin cement thickness does not affect the push-out bond strength.

Keywords: Circular fiber post; Oval fiber post; Push-out; Resin cement thickness.

Fig. 1. (A) Cervical aspect of circular fiber-post slice (R represents the radius of the circular post). (B) Apical aspect of circular fiber-post slice (r represents the radius of the circular post). (C) Cervical aspect of oval fiber-post slice (A, B, C, D, E, F points were used to determine the distance of AB, OH, HD, radius of ovality [r₁]; and, ML, L, DL, D, DB, B, MB, M points were used to measure the resin cement thicknesses). (D) Apical aspect of oval fiber-post slice (A', B', C', D', E', F'points were used to determine the distance of A'B', O'H', H'D', radius of ovality [r₂].