Laboratory evaluation of surface treatments for composite repair

This laboratory study evaluated the strength of composite repairs using various surface treatment procedures. Roughening a previously cured composite surface, with either a diamond instrument or aluminum oxide air abrasion, yielded composite to composite repair strengths that were not significantly different (P > 0.05) than bonding composite to the air-inhibited layer of a cured composite. The bond strengths of composite repairs were slightly higher when using an unfilled bonding agent but not significantly different (P > 0.05) than the same repair techniques without the bonding agent.