Efficacy of Atmospheric Pressure Plasma Jet-Induced Surface Treatment on Wettability, Surface Topography, and Shear Bond Strength of Ceramic Surfaces for CAD-On Assembly

This study evaluated the effectiveness of atmospheric pressure plasma jet (APPJ) treatment on the surface characteristics and bond strength of zirconia and lithium disilicate ceramics for CAD-on restorations. A total of 70 cylindrical-shaped specimens of lithium disilicate and 70 disc-shaped specimens of Y-TZP zirconia were machined, thermally processed, surface-treated, and then resin-bonded. The specimens were grouped according to the following surface treatments: no surface treatment, sandblasting, plasma, sandblasting followed by plasma, sandblasting followed by universal adhesive, plasma followed by universal adhesive, and sandblasting and plasma treatment followed by universal adhesive. The treated surfaces were subjected to a wettability assessment via contact angle measurement and a topography assessment using scanning electron microscopy (SEM). The cemented assembly was subjected to shear bond strength testing with a universal testing machine, and the results were imported to SPSS 23.0 for statistical analysis. The results show that APPJ treatment induced a significantly low contact angle for both ceramics with no surface alteration upon scanning. Moreover, APPJ treatment produced a bonded assembly with a shear bond strength comparable to sandblasting. In conclusion, APPJ treatment should be considered an efficient surface treatment with a non-destructive nature that surpasses sandblasting with the provision of a high shear bond strength between CAD-on ceramics.