Effect of Glass–Ceramic Spray Deposition on Bond Strength to Zirconia

Objective To evaluate the effect of glass–ceramic spray deposition and artificial aging on the shear bond strength (SBS) of a resin cement to zirconia. Materials and Methods One hundred Y‐TZP zirconia specimens were assigned to five groups ( n = 20): airborne‐particle abrasion (APC, control), lithium disilicate spray coating (LC), glaze paste (GP), and two glaze spray systems (ES and NS). APC specimens were air‐abraded, whereas coated groups were etched with 5% hydrofluoric acid. All specimens received a silane/MDP ceramic primer application and were bonded with dual‐cure resin cement. Half of the specimens were tested after 24 h and half after thermocycling (10,000 cycles). Data were analyzed using a two‐way ANOVA and Tukey's test ( α = 0.05). Results Surface treatment and aging significantly affected SBS ( p < 0.001). Thermocycling reduced SBS in all groups. APC showed the highest SBS under both conditions, followed by LC. No differences were observed among glaze groups after thermocycling. Conclusions APC showed the highest short‐ and long‐term bond strength among all groups, followed by LC, which demonstrated better bonding performance than glaze‐based systems. After thermocycling, SBS decreased in all groups, and LC revealed about half the SBS recorded for APC.