Bond strengths of three types of fibre-reinforced post systems in various regions of root canals.

AIM: To evaluate the bond strengths of three adhesive/resin cement/fibre post systems to coronal, middle and apical thirds of post space dentine. METHODOLOGY: Three types of glass-fibre post systems were selected for the study. Saremco Post Non-stop Fibre (Saremco), FRC Postec Plus (Ivoclar Vivadent) and Anatomical Post (Dentalica) were luted in prepared root canals using adhesive system and resin cement provided by the respective manufacturer. The luting agent was placed into the root canal using a specific syringe with needle. A push-out test was performed on sections from the apical, middle and coronal parts of each specimen to measure bond strength. All fractured specimens were observed using a stereomicroscope to identify the modes of failure. RESULTS: Bond strength values were significantly affected both by the post-adhesive-cement system used and by root region (P < 0.05). Additionally, there was no significant interaction between the post system and region of canal factors (P > 0.05). The highest bond strength values were found in the coronal third for all experimental groups. The middle and apical thirds exhibited similar bond strengths with no statistically significant differences amongst them. Saremco and Precision post systems had the highest retentive strengths, whilst the Ivoclar post system had the lowest values. Microscopic analysis of the specimens revealed a prevalence of post-cement and mixed failures. CONCLUSIONS: Type of post-adhesive-cement system and root position had a significant effect on fibre post retention. The coronal region of the canals was characterized by significantly higher bond strengths.