Influence of cleaning methods on bond strength to saliva contaminated zirconia

Objective To evaluate the influence of saliva contamination and cleaning procedures on shear bond strength (SBS) of a self‐adhesive resin cement (SAC) to zirconia surfaces. Materials and Methods A total of 160 sandblasted zirconia blocks were randomly divided into eight groups as follows: No saliva contamination, no cleansing (NC‐NC); contamination with saliva, no cleansing (SC‐NC); no saliva contamination, cleansing with a zirconia primer (ZP; Z‐Bond, Danville Materials, Inc., S. Ramon, California) (NC‐ZP); contamination with saliva, cleansing with ZP (SC‐ZP); no saliva contamination, cleansing with hydrofluoric acid (HF; Ultradent Porcelain Etch; Ultradent Products, South Jordan, Utah) followed by cleansing with ZP (NC‐HF‐ZP); contamination with saliva, cleansing with HF followed by cleansing with ZP (SC‐HF‐ZP); cleansing with ZP, contamination with saliva, cleansing with ZP (ZP‐SC‐ZP); application of ZP, contamination with saliva, cleansing with HF followed by cleansing with ZP (ZP‐SC‐HF‐ZP). Cylindrical resin composite blocks were luted to the zirconia surfaces with SAC (Clearfil SA Cement Automix, Kuraray, Inc., Tokyo, Japan). Specimens were subjected to shear forces at a cross‐head speed of 0.5 mm/min. Data were analyzed with Analysis of Variance and Tukey tests (α = 0.05). Results The bond strength values to zirconia were significantly influenced by saliva contamination (P