Materials and Methods: Forty-eight zirconia disks were divided into three groups according to the method of surface
treatment: polished surface, air abraded, or ground using a special silicon carbide bur (SiC Grinding Bur). All
specimens were primed using a primer containing MDP (Cimara Zircon, Voco) and then bonded to composite in
Plexiglas tubes using dual-curing adhesive resin (Bifix QM, Voco). Each of the three groups was further divided into
two subgroups (n = 8) stored either in water at 37ºC for 3 days without thermocycling or stored in water at 37ºC for
150 days with an additional 37,500 thermocycles between 5ºC and 55ºC. After storage, tensile bond strength
(TBS) was measured in a universal testing machine.
Results: After 3 days of storage, silicon carbide bur and air-abraded groups showed high TBS that ranged from
32.7 to 41.0 MPa (p ≤ 0.05). After 150 days of storage with thermocycling, the air-abraded group showed the most
durable TBS (34.8 MPa), while the silicon carbide bur group showed a significant reduction in TBS (21.2 MPa); in
the polished control group, specimens all debonded spontaneously during storage (p ≤ 0.05).
Conclusion: Repair of zirconia ceramic after chipping of its veneers showed durable TBS when surface conditioning
with air abrasion or roughening of the zirconia surface with a silicon carbide bur was provided.