The effects of thermal and occlusal stresses on the microleakage of the Scotchbond 2 dentinal bonding system.

The microleakage of the Scotchbond 2 Dentinal Bonding System was evaluated under various experimental conditions. In this in vitro study, Class V restorations involving both enamel and cementum were placed on the buccal surfaces of 54 extracted human permanent canines and on the buccal and lingual surfaces of eight extracted human permanent mandibular molars. The canines were divided into three groups, each undergoing different conditions of thermocycling in 0.5% basic fuchsin or distilled water and storage time in the dye. The molars were subjected to an occlusal load of 8 MPa for 66,000 times prior to being thermocycled. There were no significant differences in microleakage of the restorations placed in the canine teeth; however, microleakage in the group of molars subjected to occlusal stresses was significantly increased. This may have been due to the increased length of the restorations placed in the molar teeth.