Microtensile bond strengths of short surface-coated intraradicular posts

Actual endodontic and reconstructive concepts require posts. In this trail short posts with a coronal retentive head received tribochemical-surface coating (Tbc). The microtensile-bond-strengths (μTBS) of the new short posts with and without additional coating were compared with the conventional posts concerning post and luting material. Root canals of 120 freshly extracted human anterior-teeth were endodontically treated to ISO size 80/length 6 mm and randomly divided into 3 groups (n = 40): Root canals of each group were prepared using respective drills of the post-system for the conventional posts (I), the new short posts without coating ((II), prototyp) and with coating (III). Posts of two materials (titanium and FRC) were inserted using two composites (RelyX-Unicem (RX), DentinBuild-Evo (DB)). After Thermocycling (5°/55 °C, 5000×) push-out-testing was performed for the coronal (CR), medium (MR) and apical (AR) region-of-the-post. Statistical analysis was performed (ANOVA, Bonferroni correction, α = 0.05). Highest values of μTBS were found for the short, coated posts (III) luted with DB at the (CR) (FRC:11.8 ± 7.5 N/mmÇ, Ti:13.7 ± 7.9N/mmÇ). Yet, conventional posts without coating (I) ranged on the same level at (CR) (FRC/DB:10.8 ± 3.1N/mmÇ, Ti/DB:8.7 ± 5.1N/mmÇ). μTBS decreased not significantly apically within all groups. μTBS of (II) were lower compared to (I) + (III) (p > 0.05). Posts luted with RX showed similar μTBS regardless of the area of the post-type as well as the post-material (p > 0.05). Yet, overall post types as well as post segments turned out to be significant factors (p < 0.05, 4-way ANOVA). Short, coated posts of Ti as well as FRC revealed at least similar μTBS to those of the conventional posts luted with both investigated composites cements.