This in vitro study evaluated the marginal microleakage of amalgam restorations associated with the cavity varnish Copalite - Cooley & Cooley (GI-CP), dentin adhesive OptiBond Solo - Kerr (GII-OS) and the glass ionomer cement Vitremer - 3M (GIII-VT). Forty-five premolars were employed, which were submitted to independent class II preparations at the mesial and distal aspects comprising the marginal ridges and were restored with Dispersalloy - Dentsply. Afterwards, the teeth were thermocycled and stored in 0.5% basic fuchsine for 24 hours. The evaluations were conducted on a light microscope with 150x magnification and on the Sigma Scan software with employment of a single line and segmented lines. Data analysis allowed to establish that none of the materials was able to eliminate the marginal microleakage, having the GI - CP presented greater and statistically significant values in relation to the other groups in all evaluation methods (p<0.05). The lowest values were displayed by the GIII-VT, yet with no statistically significant difference when compared to GII-OS, except for the evaluation at the Sigma Scan in single line. The three evaluation methods showed a strong positive relationship to each other.
Dental materials; Marginal microleakage