The degree of microleakage at 14 days, 6 months and 1 year between Class V amalgam restorations lined with Copalite varnish or with Amalgambond was compared in this in vitro study. The restored teeth were subjected to cyclic occlusal loading, thermocycling procedures and then stored in a dye solution at the appropriate intervals. Dye penetration was assessed at the gingival and occlusal margins of the restorations. The results showed that with Amalgambond, there was significantly better sealing of the dentin tubules than with Copalite or unlined restorations (P < 0.001) at all times tested. Amalgambond showed significantly less microleakage as compared to unlined restorations (P < 0.01) at all time periods, and significantly less short-term (14 days) microleakage compared with the Copalite-lined group (P < 0.01).