Purpose: To evaluate the marginal integrity of amalgam restorations in association with four different bonding agents in an in vitro stressing system. Materials and Methods: Cylindrical cavities were prepared in extracted human molars. The enamel-dentin interface of each cavity was treated with one of four different bonding agents and a non-bonded group. Following treatment with one of the four systems; Amalgambond (AB), Amalgambond Plus (AP) Superbond D-liner II (SD) and Bond-It (BI). Each cavity was then restored with a high-copper spherical amalgam alloy Tytin (TY). Using a load of 75 Newtons (N), a total of 100.000 cycles were applied to each restoration surface. Marginal integrity of each tooth restoration interface was replicated with epoxy and evaluated for gap width with a profilometer and SEM. Results: There were no significant differences in gap width between the loaded and unloaded groups. The non-bonded group (before loading) was statistically different than AB, AP, and SD. In addition, there were no significant differences among the 4-META bonded groups, regardless of the type of bond system, whether loaded or unloaded. The four different bonding agents were significantly different after loading than the non-bonded group. Our SEM and profilometry data demonstrate that the marginal integrity of amalgam alloy restorations is significantly improved by use of bonding systems.