Shear Bond Strength of Cemented Ceramic Crown Materials to Zirconia

Objective: The purpose of this study was to evaluate the shear bond strength of three adhesive cements for the purpose of bonding three types of ceramic crown materials to zirconia abutments.

Methods: Milled zirconia plates were mounted in acrylic (n=90). The zirconia specimens were divided into 3 separate groups: (G1) Multilink Automix (Ivoclar Vivadent, Inc.); (G2) Relyx Unicem (3M Espe); (G3) Panavia F 2.0 (Kuraray Medical, Inc.). Leucite reinforced ceramic rods (a), lithium disilicate rods (b) and zirconia rods (c) were treated according to the manufacturer's instructions and cemented to the zirconia plates. All specimens were light cured using a halogen light, set on high power, for 40 seconds. Each group was stored in water at 37°C for 24 hours before testing. Specimens were tested in a universal testing machine (Instron Corporation) at a crosshead speed of 1 mm/min. Mean shear bond strengths were calculated and subjected to statistical analysis (ANOVA, p<0.05).

Results: Shear bond strength values (MPa): G1a: 15.0 (±2.9); G1b: 17.0 (±5.2); G1c: 19.9 (±7.8); G2a 9.8 (±4.8); G2b: 14.5 (±6.5); G2c: 14.2 (±7.3); G3a: 12.6 (±6.8); G3b: 14.8 (±8.7); G3c: 19.2 (±7.8). No statistical difference was seen between the different ceramic crown materials for each group. All the shear bond strengths measured showed acceptable bonding to zirconia as a potential way to bond ceramic crowns to zirconia abutments.

Conclusion: All three tested cements exibited values between 10 and 20 MPa for bonding glass based ceramics to zirconia.