Nonthermal Plasma Treatment Can Eliminate Sandblasting Procedure For Zirconia-Resin Cement Bonding

Purpose: To evaluate the effects of nonthermal atmospheric plasma (NTAP) treatment, alone or combined with sandblasting and/or primer application, on the bonding of zirconia ceramics to resin cement. Materials and Methods: A total of 420 discs of Y-TZP (2 x 15 x 12 mm) were prepared and randomly divided into 10 groups according to surface treatment, as follows: Z (control), SB (sandblasting), Pr (primer), SBPr (sandblasting + primer), P (NTAP), SBP (sandblasting + NTAP), PrP (primer + NTAP), SBPrP (sandblasting + primer + NTAP), PPr (NTAP + primer), and SBPPr (sandblasting + NTAP + primer). After surface treatments, the surface roughness values were evaluated using a profilometer, and the contact angle measurements were performed using a goniometer. Surface characterizations of the groups were analyzed using scanning electron microscopy and x-ray photoelectron spectroscopy analyses. Shear bond strength tests were performed after adhesive cementation in 20 specimens per group, with half (n = 10) subjected to thermocycling (5,000 cycles, 5 degrees C to 55 degrees C). The failure mode was recorded by examining each specimen using a stereomicroscope. One-way and two-way ANOVA followed by Student-Newman- Keuls test (a = .05) were used to analyze the data statistically. Results: Untreated zirconia surfaces (without sandblasting) were found to have a higher wettability and oxygen ratio after NTAP treatment. The clinical application order of NTAP is an important factor, and the best combination for bonding quality was NTAP treatment followed by primer application on untreated zirconia (group PPr), rather than on a sandblasted surface. Conclusion: NTAP application may be a promising surface treatment method for adhesive cementation of zirconia ceramics as an alternative to sandblasting. To achieve strong adhesion, NTAP should be applied before primer application