Tensile bond strength of a resinous cement to a nickel-chromium alloy modified with five surface treatments

A problem associated with resin-bonded fixed partial dentures is inadvertent dislodgment at the metal/cement interface. It has been suggested that Panavia Ex resinous cement requires only air abrasion of the alloy with 50 mu m aluminum oxide particles to record reliable bond strength values. The purpose of this study was to discuss the consequences of changes in the type of air abrasion and surface oxidation of the alloy. Fifty pairs of disks of a Ni Cr alloy were treated by five methods: (1) air abrasion with 50 mu m aluminum oxide (control), (2) air abrasion with 50 mu m glass beads, (3) air abrasion with a mixture of aluminum oxide and glass beads (ratio 1:1), (4) air abrasion with aluminum oxide and immersion in acid solution of potassium permanganate, and (5) air abrasion with aluminum oxide and immersion in aqueous solution of potassium permanganate. The disks were cemented to each other with Panavia Ex composite resinous cement and tensile tests were conducted at a crosshead speed of 0.5 mml minute. No statistically significant differences were recorded among the treatments for the alloys used in this study except air abrasion with glass beads, which exhibited the lowest bond strength values.