Effect Of Primer Thermal-Treatment On Resin Cement/Y-TZP Bond Strength

Objectives: To evaluate the effect of different temperatures (thermal treatment) of the Metal/Zirconia primer (Ivoclar Vivadent Ltda.) on the shear bond strength of a MDP-based resin cement to a Y-TZP ceramic. Methods: Specimens with (4.5x3.5x4.5)mm³ were produced from InCeram 2000 YZ cubes (Vita Zanhfabrik) and embedded in PMMA. After the finishing, the specimens were cleaned in sonic device under water and randomly divided in 5 experimental groups (n=12) according to the thermal treatment at an oven of the Metal/zirconia primer: GC (Control) – without primer; G20 – primer application at ambient temperature (20°C); G45 – primer application + thermal treatment at 45°C; G79 – primer application + thermal treatment at 79°C; G100 – primer application + thermal treatment at 100°C. A cylinder of MDP-based resin cement (2.5mm in diameter) was built on the ceramic surface of 10 specimens of each experimental group and stored for 24 hours at 37°C. The specimens were submitted to a shear bond strength test (n=10). Analysis in FT-Raman and Thermal Gravimetric Analysis (n=2) were performed. The obtained data were statistically analysed by ANOVA and Tukey's test (a-0.05). Results: The experimental group G79 (5.2 ± 2.2 MPa) presented a significant higher mean than the others experimental groups (GC: 2.3 ±1.3; G20: 2.2 ±0.7; G100: 2.8 ±1.2), not differing only from G45 (G45: 3.7 ±1.8). Conclusion: It seems that the thermal treatment of Metal/zirconia primer at 79° C is effective to improve the bond strength of a MDP-based resin cement to a Y-TZP ceramic.