Effects of etching and adhesive applications on the bond strength between composite resin and glass-ionomer cements

Objective: this study determined the effects of various surface treatment modalities on the bond strength of composite resins to glass-ionomer cements. material and methods: conventional (ketac™ molar quick applicap™) or resin-modified (photac™ fil quick aplicap™) glass-ionomer cements were prepared. two-step etch-rinse & bond adhesive (adper™ single bond 2) or single-step self-etching adhesive (adper™ prompt™ l-pop™) was applied to the set cements. in the etch-rinse & bond group,the sample surfaces were pre-treated as follows: (1) no etching,(2) 15 s of etching with 35% phosphoric acid,(3) 30 s of etching,and (4) 60 s of etching. following the placement of the composite resin (filtek™ z250),the bond strength was measured in a universal testing machine and the data obtained were analyzed with the two-way analysis of variance (anova) followed by the tukey's hsd post hoc analysis (p=0.05). then,the fractured surfaces were examined by scanning electron microscopy. results: the bond strength of the composite resin to the conventional glass-ionomer cement was significantly lower than that to the resin-modified glass-ionomer cement (p<0.001). no significant differences were determined between the self-etching and etch-rinse & bond adhesives at any etching time (p>0.05). however,a greater bond strength was obtained with 30 s of phosphoric acid application. conclusions: the resin-modified glass-ionomer cement improved the bond strength of the composite resin to the glass-ionomer cement. both etch-rinse & bond and self-etching adhesives may be used effectively in the lamination of glass-ionomer cements. however,an etching time of at least 30 s appears to be optimal.