Effect of metal conditioners on porcelain-alloy bond strength

The effect of three metal conditioners on the apparent bond strength of a single porcelain to four alloys was evaluated. On the basis of the bond strength data the following conclusions can be drawn. The use of metal conditioners provided no improvement in the apparent porcelain-alloy bond strength of Biocast and Biobond alloy. The use of Unibond alloy with its recommended conditioner Uniseal gave lower bond strength values than Unibond without the conditioner. With Rexillium III alloy the use of Uniseal gave the highest bond strength values, but these were statistically equal to those obtained with the recommended coating agent (Jeneric bonding agent). With the exception of Rexillium III alloy, it appears that coating agents may have a function other than bond strength improvement. In light of the continued marketing of new alloys, bonding agents, and porcelains, further research is needed to determine the mechanism of action of bonding agents as well as the porcelain-bonding agent-alloy interaction of various commercial products. Studies designed to address these topics are in progress.