Bond Strength Of Dental Posts with Zinc Phosphate Luting Cement

Objective: Post retention to root canal dentine is an important parameter that directly affects the restoration success. The objective of this in-vitro study was to examine the push-out bond strength of four commonly used dental posts including titanium alloy, fiber, stainless steel, and new experimental zirconia posts luted with zinc phosphate cement. Methods: Forty extracted single-rooted canine teeth were randomly divided in four groups (N=10) and restored using four selected types of dental posts; titanium and stainless steel posts (Para Post XP, Coltene/Whaledent, USA), fiber posts (Para Post Fiber Lux, Coltene/Whaledent, USA), and the new experiment zirconia posts (BTS Tools Manufacturing Sdn Bhd, MALAYSIA) with conventional zinc phosphate luting cement (Elite 100Ò, GC Corp, Japan). The mixed luting cement paste was inserted into a parallel post spaces, 1.25±0.01 mm (diameter) and 15.00±0.01 mm (length) with a spiral file and applied to the post surface that was seated into the canal. After water storage for 7 days at 37°C, the teeth were sectioned horizontally to obtain three disc-shaped specimens (coronal, middle and apical) with thicknesses of 2mm from each tooth. The specimens were further subjected to push-out tests using a universal testing machine at a cross-head speed of 0.5 mm/min. Statistical analysis was performed using SPSS Statistics 22 and general linear repeated measure with 95% confidence interval. Results: The results showed a significant interaction between the push-out bond strength and the type of dental post. The mean push-out bond strengths in the middle sections of fiber-reinforced post (2.41±2.45 MPa) were significantly higher than titanium (0.98±0.92 MPa), stainless steel (1.44±1.39 MPa), and new-experiment Zirconia (1.11±0.95 MPa) posts. Conclusion: With the limitation of this study, fiber post has the highest bond strength to the root dentin than other type of evaluated posts in push-out tests.