BackgroundWith the increased demand for aesthetic procedures as well as the development of bonding systems, the applied composites are routinely and widely used for direct restorations (1-3).In recent years, in spite of the considerable advances in resin composite components, marginal failures have occurred due to abrasion, discoloration, secondary decay, polymerization contraction, microleakage, poor anatomical form, pain and tenderness, which limit the composites' lifetime (3-8). In these cases, selected treatments include repair or replacement of the entire restoration. The repair is a conservative process, so that there is no need for removing entire restoration and the minimum cavity preparation is only required (9). Repairing old composite restorations is considered as a challenge due to the reduction of its free radicals after the