ABSTRACT
INTRODUCTION: The aim of this study was to evaluate the push-out bond strengths of a new polyfiber post system and a fiber post that were adhesively luted with a dual-cure resin cement. METHODS: Forty single-rooted human maxillary teeth were sectioned below the cementoenamel junction, and the roots were endodontically treated. The roots were randomly divided into 2 groups of 20 specimens each according to the post type used: SpiraPost (group A; DMG, Englewood, NJ) and DT Light-Post Illusion X-RO (group B; Bisco Inc, Schaumburg, IL). All posts were cemented with dual-cure resin cement. Bonded specimens were cut into 1-mm-thick sections, and push-out tests were performed using a universal testing machine. All specimens were loaded until fracture, and the failure modes were evaluated with a stereomicroscope at 50× magnification. Representative specimens were analyzed by scanning electron microscopy. RESULTS: Push-out bond strength was significantly affected by the type of post (P < .05). In all root sections, the SpiraPost push-out bond strength values were significantly higher than that those of DT Light-Post Illusion X-RO (P < .05). Cohesive failure within the post was the most frequent type of failure for the SpiraPost system. CONCLUSIONS: In all root segments, the SpiraPost system provided significantly increased post retention compared with the fiber post.
