Adhesion of glass ionomer cement to a ceramometal alloy

Glass ionomer cements can be used for restoring minor caries lesions, sealing an endodontic access, and repairing defective margins of inlay-onlay restorations. Little information is available on the adhesion between ceramometal alloys and various types of glass ionomer cements.

The aim of this study was to determine whether the adhesion of glass ionomer cement to the surface of a ceramometal alloy could be enhanced with pretreatment of the alloy surface.

Six groups of five specimens were either ground with a diamond bur, sandblasted with aluminum oxide, or ground with a silicon-carbide stone before bonding to either conventional glass ionomer or resin-glass ionomer cements. Resistance to bond failure was tested with a three-point loading test.

The results revealed that the greatest resistance to bond failure was obtained by the resin-glass ionomer cement to the sandblasted alloy surface and the least resistance by the glass ionomer cement to the diamond ground alloy surface (p < 0.001). Both the type of glass ionomer cement (p = 0.002) and the type of mechanical treatment (p = 0.001) affected the resistance to bond failure.

This study suggests that pretreatment of alloy surfaces with a sandblasting device may be recommended when repairing marginal defects of alloy restorations with glass ionomers. Resin-glass ionomer cements seem to give better adhesion than conventional glass ionomer cements do.