Microleakage of amalgam cavity treatment systems: an in vitro evaluation

to evaluate the effectiveness of four cavity treatment systems for their ability to seal standardized Class V restorations of amalgam.

The Celay copy-milling machine was used to prepare twenty-five standardized Class V cavities on the buccal and palatal surfaces of maxillary premolar teeth extracted for orthodontic purposes. The cavosurface margins lay entirely within enamel. Five cavity treatment test groups were employed prior to amalgam placement: Group 1, Cervitec; Group 2, Gluma One Bond; Group 3, Panavia 21; Group 4, Copaliner Dentin Varnish and Sealant and Group 5, Control. Following restoration placement, the teeth were aged at room temperature (25 +/- 2 degrees C) in tap water for 2 months. The specimens were subsequently thermocycled (500 cycles, 5 -55 +/- 2 degrees C), immersed in a dye solution, sectioned and scored for microleakage. Scanning electron microscopy was employed to examine features of the tooth/restoration interface.

None of the materials tested consistently prevented microleakage. No statistically significant differences were identified between the groups with respect to the microleakage scores (P > 0.05). The gingival walls exhibited significantly more microleakage than the occlusal walls (P = 0.00). No significant differences were identified between the microleakage scores obtained for the buccal and palatal cavities. Scanning electron microscopy examination failed to demonstrate a consistent pattern of interfacial appearance, showing a combination of cohesive and adhesive failure within and between test groups.