Non-thermal Plasma Improves the Y-TZP/Veneering Ceramic Interface Bond Strength

Objectives: This study evaluated the effect of non-thermal plasma treatment (NTP) on the (i) physical and chemical properties of Yttria-stabilized Tetragonal Zirconia Polycrystal (Y-TZP) and (ii) shear bond strength between Y-TZP and veneering ceramic. Y-TZP samples (13mm x 5,4mm x 5mm) were divided in 6 groups: no treatment (C - control), sandblasting with aluminum oxide particles of 30µm (Al₃₀), 110µm (Al₁₁₀), 250µm (Al₂₅₀), liner (L) and NTP.
Methods: Surfaces were characterized using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), atomic force microscopy (AFM), perfilometry and surface energy. Shear bond strength testing was performed at the Y-TZP/vennering ceramic interface in a universal testing machine at a crosshead speed of 1 mm/min. Data were analyzed using 1-way ANOVA and Tukey HSD test (α=.05).
Results: NTP and Al₃₀ exhibited the lowest surface roughness values (P<.05) that were similar to control (P>.05). All surface treatments improve the surface energy of Y-TZP (P<.05), except Al₃₀. SEM-EDS showed the presence of silicon thin film for the NTP group and aluminum oxide film for the Al₃₀ group. NTP showed the highest bond strength value (P<.0001 vs control) whereas other groups did not differ from control (P>.05).
Conclusions: NTP is an effective treatment option for improving the shear bond strength between Y-TZP and veneering ceramic.