Shear bond strength of Zirconia to different adhesive resin cements.

Abstract

Objectives: This in-vitro study investigated the shear bond strengths(SBS) and failure modes of 2 resin cements bonded to zirconia core ceramic. Materials and methods: Forty square-shaped (8 mm x 8 mm x 2 mm) and cylinder-shaped (5 mm diameter and 3 mm height) zirconia blocks were prepared and randomly assigned into two groups (n=20). In Group 1, the square-shaped zirconia specimens were bonded to the cylindrical zirconia using RelyXTM Ultimate in combination with ScotchbondTM Universal adhesive. In Group 2, the bonding of zirconia specimens was made using PanaviaTM F2.0. Punched adhesive tape with 5 mm diameter hole was placed on the square- shaped zirconia blocks to restrict the bonding surface area. Before bonding, the surfaces of the square and cylinder-shaped blocks were sandblasted with 50 μm Al2O3 at 2-bar pressure. After bonding, specimens were stored in distilled water at 37 ˚C for 24 hrs and then shear bond test was performed using a universal testing machine. The bond strength data were analyzed using an independent t-test at α = 0.05. Results: There was no significant difference between shear bond strength of either RelyXTM Ultimate (17.2 ± 6.0 MPa) or PanaviaTM F 2.0 (15.8 ± 4.4 MPa) bonded to zirconia. The failure in all specimens originated at the interface between resin cement and zirconia. Conclusion: The shear bond strength of RelyXTM Ultimate was comparable to the group bonded to PanaviaTM F 2.0 bonded to zirconia. The failure mode of all specimens was interfacial failure.