Effect of Different Durations of Nonthermal Plasma Treatment on Zirconia-Resin Bond Strength

To study the surface characterization and bonding strength of zirconia ceramics following nonthermal argon plasma (NTAP) treatment of different durations.

Zirconia ceramics were cut into two sizes of specimens-50 specimens of Type I (10 × 10 × 2 mm) and 50 specimens of Type II (3 × 3 × 2 mm)-which were randomly divided into five groups (n = 10): blank (group A), sandblasting (group B), and NTAP treatment for 60, 90, and 120 seconds groups (groups C, D, and E, respectively). The changes in surface morphology, roughness, carbon (C) and oxygen (O) elements, and contact angle of sample surfaces were tested with Type I specimens. Type II specimens received the uniform surface treatments and were cemented to isolated teeth using RelyX U200 cement, and the samples were submitted to a shear bond strength (SBS) test.

Scanning electron microscopy (SEM) and atomic force microscopy (AFM) showed that NTAP treatment did not alter the surface morphology and roughness of zirconia ceramics. The amount of C decreased and the amount of O increased, and the contact angle became smaller after NTAP treatment. Among the five groups, group D showed the most extensive changes, and the result of SBS was as follows for NTAP treatment time: 0 < 60 < 90 = 120 seconds (among 60- and 90-second groups, P < .05).

NTAP treatment can improve the bond strength of zirconia ceramic by increasing its surface energy and wettability, and the NTAP treatment for 90 seconds may be a suitable surface treatment method for zirconia ceramics.