Evaluation of the effect of intermediate agents on the shear bond strength of repaired aged silorane resin composite


Background: The aim of this study was to evaluate the bonding effect of different intermediate agents on the bondstrength of silorane resin composite (Filtek™ P90,3M ESPE) that repaired by either silorane (Filtek™ P90) ormethacrylate based resin composite (Filtek™ Z250,3M ESPE)Materials and Methods: Eighty specimens of resin composite prepared by filling silorane (Filtek™ P90) into a retentivecavity (6mm in diameter and 2mm in depth) of acrylic mold. The composite were polymerized, water stored at 37°Cfor one week. Their surface were finished with medium (violet) super-snap disks then rinsed in ultrasonic cleaner.Repair was performed with either silorane (Filtek™ P90) or methacrylate based composite (Filtek™ Z250) by usingseveral intermediate agents which include (P90 System Adhesive, Adper Scotchbond Multipurpose and Clearfilrepair kit).The shear bond strength (crosshead speed 0.5 mm/min) was measured after an additional water storageof 24 hour.Results: Statistical analysis of data revealed that intermediate agents enhanced the bond strength significantly(p<0.001).The highest shear bond strength were determined for Clearfil repair kit and P90 System Adhesive whichwere significantly higher than the control (p<0.001). Adper Scotchbond Multipurpose enhanced the bond strengthsignificantly than the control but it was significantly lower than the other adhesive systems (p<0.001).Conclusions: The Clearfil™ Repair kit and P90 System Adhesive were the most effective intermediate agents for repairof silorane restoration with both silorane and methacrylate repair materials.Use of Adper Scotchbond Multipurposeresulted in bond strength which is considered clinically inadequate