Microleakage of selected composite restorative resins

Five selected composite restorative resins were used to restore Class V preparations in extracted human maxillary canine teeth. In addition, a low-viscosity bonding resin was used in conjunction with one of the restorative resins. Microleakage, at both the incisal and cervical margins of the restorations, was assessed by means of a radioisotope after the restored teeth had been subjected to 2500 cyclic temperature changes at 5° and 55°, respectively. Incisal microleakage was not significantly different but severe microleakage was recorded at the cervical margins of the restorations.