The effect of air abrasion with two new bonding agents on composite repair.

This study evaluated the shear bond strength of repairs made with a composite (Herculite/Kerr) when two different surface treatment methods and two new generation bond materials were used. The bonding surfaces were prepared by sanding with 500-grit aluminum oxide sandpaper or air abrading with 25-micron aluminum oxide. Treated resin surfaces were acid etched, washed for one minute and air dried. Before adding the composite Herculite, either Optibond Solo (Kerr), Solobond M (Voco) bonding agent or no bonding agent (control group) was applied. The specimens were evaluated for shear bond strength after thermocycling. Fracture surfaces of some samples were also evaluated with SEM. Light microscope and SEM examination of fractured repair surfaces indicated mostly cohesive failure within the air-abraded group. The results showed that surface treatment with air abrasion plus Optibond Solo application had the highest shear bond strength.