MARGINAL INTEGRITY OF BONDED AMALGAM RESTORATIONS

Purpose: To evaluate the marginal integrity of amalgam restorations in association with four different bonding agents in an in vitro stressi ng system. Materials and Methods: Cylindrical cavities were prepared i n extracted human molars. The enamel-dentin interface of each cavity w as 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 al loy Tytin (TY). Using a load of 75 Newtons (N), a total of 100.000 cyc les were applied to each restoration surface. Marginal integrity of ea ch tooth restoration interface was replicated with epoxy and evaluated for gap width with a profilometer and SEM. Results: There were no sig nificant differences in gap width between the loaded and unloaded grou ps. The non-bonded group (before loading) was statistically different than AB, AP, and SD. In addition, there were no significant difference s among the 4-META bonded groups, regardless of the type of bond syste m, whether loaded or unloaded. The four different bonding agents were significantly different after loading than the non-bonded group. Our S EM and profilometry data demonstrate that the marginal integrity of am algam alloy restorations is significantly improved by use of bonding s ystems.