Push-out Tests of Fiber Posts Luted with Different Resin Cements

Objectives: The aim of this study was to evaluate the bond strengths of six different resin cements to fiber posts. The posts received different surface treatments to determine the effect on bond strengths. Methods: 180 fiber posts (FRC Postec/Vivadent/Ivoclar) were divided into 3 groups of 60 posts each and received the following surface treatments. Control group: disinfection with alcohol; group 2: silane treatment with Monobond S (Vivadent); group 3: Cojet (Dento-prep) treatment followed by silane coating with ESPE-Sil (3M ESPE). The posts were luted into standardized drill holes of methacrylate barrels performed with drills provided by the manufacturers of the post system. All posts were inserted with the following luting cements according to manufacturers’ recommended procedures: Panavia F (Kuraray), Multilink (Vivadent), Variolink (Vivadent), PermaFlo DC (Ultradent), RelyX Unicem (3M ESPE) and Clearfil (Kuraray). The samples were sectioned transversally with a microtome saw and four slices of 2 mm thickness were obtained. Push-out tests were performed using a universal-testing machine. The maximum failure load was recorded in N and converted into MPa. Results: The observed bond strengths (MPa) of the different resin cements to the fiber posts were significantly affected by the type of cement (p<0.001; One-way Anova). The different surface treatments of the posts had no influence on bond strengths (p=0.666; One-way Anova). Clearfil had significantly higher bond strength values to the posts than all other tested materials (p<0.05, Tukey-B). Bond strengths of Panavia F and RelyX Unicem were significantly higher compared to Variolink, Multilink and PermaFlo (p<0.05, Tukey-B). Conclusion: The bond strengths of the different luting cements to the posts were affected by the type of cement. The tested surface treatments of fiber posts had no influence on bond strengths.