Effect of selective infiltration etching on the bond strength between zirconia and resin luting agents.

OBJECTIVE: To evaluate the shear bond strength of resin cements to zirconia treated with the selective infiltration etching technique (SIE).

MATERIALS AND METHODS: Forty-seven zirconia specimens were prepared with a sequence of silicon carbide abrasives, cleaned in an ultrasonic bath. Three samples were separated for atomic force microscope (AFM) analyses (one nontreated for control, one sandblasted, and one selective infiltration etched) and the remaining were randomly distributed in four groups, according to the combination of surface treatment and resin cement: group 1a (sandblasting + Variolink II), group 1b (sandblasting + Panavia SA Plus), group 2a (SIE + Variolink II), group 2b (SIE + Panavia SA Plus). A composite resin cylinder (3 mm × 3 mm) was cemented to the zirconia surface, as per each group's specific protocol. After storing 24 hours in distilled water at 37°C, the specimens were tested for shear bond strength and the results were subjected to statistical analysis.

RESULTS: At 24 hours, the highest SBS values were observed in group 2b, where the SIE technique was used in conjunction with Panavia SA Plus. Lowest values were found in group 1a. Increased surface roughness was observed with SIE.

CONCLUSIONS: SIE significantly enhanced the resin bond strength to zirconia. However, cement selection was also an important factor, for both surface treatments tested.

CLINICAL SIGNIFICANCE: Use of SIE method combined with MDP monomer containing resin cement can provide clinically acceptable bond strength between zirconia and resin cement.