Sealing performance of Scotchbond Multi-Purpose-Z100 in Class II restorations

To evaluate the sealing ability of Class II Scotchbond Multi-Purpose/Z100 composite restorations placed under in vivo and in vitro conditions.

For the in vivo part, Class II preparations were cut in posterior teeth which were scheduled for extraction for periodontal reasons. The cervical margins ended in dentin-cementum, 1 mm below the CEJ. The teeth were extracted after 2-3 months of clinical service. The in vitro part was performed in extracted posterior teeth, free from restorations and caries, following the same in vivo protocol. The in vivo and in vitro samples were processed and evaluated for marginal leakage.

Leakage by dye penetration was observed at the cervical margins in 70% of the in vivo and in 50% of the in vitro specimens. All in vivo samples with no leakage at the cervical margin were restored where the adjacent interproximal tooth was missing. In more than 40% of the restorations placed in vivo, leakage was also found at the occlusal margins. Statistically significant differences were found at the cervical margins between in vivo and in vitro groups (P < 0.05). The in vitro samples can be of only limited value in predicting clinical performances of an enamel-dentin bonding system in Class II restorations.