Influence of Y-TZP ceramic treatment and different resin cements on bond strength to dentin

Objectives. Evaluating the bond strength (sigma) of resin cement systems (RXA - RelyX ARC; RXU - RelyX U100; and PF - Panavia F) to dentin and yttria-stabilized zirconia-based ceramic (YZ - In-Ceram YZ) after different surface treatments and aging.Methods. Occlusal dentin of 54 human molars was exposed and conditioned following manufacturers' instructions. Fifty-four YZ blocks were sintered and divided into two groups according to surface treatment: PA - airborne particle abrasion, and SC - tribochemical silica coating. All treated YZ blocks were cemented to dentin using one of the cement systems (RXA, RXU, and PF) following manufacturers' recommendations, which includes specific silane agents. Teeth-cement-ceramic blocks were stored in 37 degrees C distilled water for 24 h before cutting into non-trimming bar-shaped specimens (adhesive area, A = 1 +/- 0.1 mm(2)). Specimens (n >= 12) were assigned to one of the following conditions: N - no storage; W stored in 37 degrees C distilled water for 60 days; and TC - thermal cycling (5-55. C; 10,000 cycles). All specimens were loaded in tension (F) to failure using a universal testing machine. The sigma (F/A) was calculated and data were statistically analyzed using ANOVA and Tukey tests (alpha = 0.05). Fracture surfaces were examined to determine the failure mode.Results. RXA-SC and PF-PA specimens showed the greatest mean sigma values after N (13.9 and 13.0 MPa, respectively) and TC (12.9 and 14.8 MPa, respectively). SC-treated showed greater mean sigma values than PA-treated YZ specimens after W.Significance. Regardless of the cement used, W and TC did not significantly reduce the sigma of SC-treated YZ resin bonded to dentin. (c) 2012 Published by Elsevier Ltd on behalf of Academy of Dental Materials. All rights reserved.