Development and physical-chemical characterization of a novel PECVD film to improve the bond strength between Y-TZP and veneering ceramic

The obtainment of a durable zirconia/veneer ceramic interface bond is a preoccupation for clinical success of metal-free restorations and did not exist evidence indicates that the technique with the best predictability and durability. Thus, the aim of this study was to develop and to physico-chemically characterize a novel film formed after plasma enhanced chemical vapor deposition (PECVD) on the yttria stabilized tetragonal zirconia (Y-TZP) surface aiming to improve its bond strength to the veneer ceramic. For this, a total of 192 YTZP samples (13×5.4×5 mm) were divided in 6 groups, according the surface treatment: control – no treatment (C), airborne-particle with 27 µm aluminum oxide (Al27), airborneparticle with 110 µm aluminum oxide (Al110), airborne-particle with 250 µm aluminum oxide (Al250), zirconia liner (L) and the film by PECVD (P). The Y-TZP surface was characterized through scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), atomic force microscopy (AFM), surface roughness and surface free energy. The bond strength between Y-TZP and veneer ceramic was tested before and after thermal fatigue (20,000 cycles of 5 and 55ºC). The data were submitted to analysis of variance and Tukey HSD test (α=0.05). The results were that the roughness of Y-TZP surface was not modified in the P group (P>0.05 vs control), while the Al110, Al250 and L groups showed higher roughness values (P<0.05). All the treatments improved the surface free energy of Y-TZP, except for the Al27 group. The P group showed higher shear bond strength (P<0.05), similar only to the Al27 group (P=0.107). The other groups were similar to control (P>0.05). The thermal fatigue did not affect the Y-TZP/veneer ceramic interface. Films produced by the PECVD deposition did not promote structural changes on the Y-TZP and are promising to improve the bond interface Y-TZP/veneer ceramic. (AU)