INTRODUCTION
Gallium, like mercury, has a low melting point and at room temperature reacts with other metals to form workable materials that harden over time. The application of gallium alloys as a filling material and alternative to amalgam has received increased attention. Two gallium alloyshave approved on the market, the Japanese government has approved one of them for clinical use [Hero, et al, 1997].
Gallium restorative alloy consists of several phases such as (Ag0.72 Ga0.28, CuGa2, Cu9 Ga4 and Cu3 Ga). The behavior of a restorative alloy depends on its phases. Properties of Gallium restorative alloys, such as corrosion resistance, mechanical strength, creep resistance and dimensional change have been studied [Hero, et al, 1997, Horasawa, et al, 1999, Shaini, et al, 2001, Dunne, et al, 2000]. The strength properties of gallium alloys have been reported to be comparable to those of amalgam. The dimensional change property measurement reveals that gallium alloys have excessive post placement expansion and it is capable of cracking dental structures [Ballester, et al, 2001]. Corrosion resistance of gallium alloys has been studied in vitro and in vivo and great corrosion was found compared with dental amalgam.
The purpose of the present work is to study the properties (electrochemical and mechanical) of gallium restorative alloy phases in vitro.