The physical properties of a gallium alloy restorative material

Objectives. This study was conducted to compare the physical properties of a gallium alloy restorative material and a widely used mercury-containing dental amalgam. Methods. Although the specimens were not prepared according to ISO specifications, specimens of both materials were subjected to ISO standard (ISO 1559; 1986) tests. The results were analyzed by ANOVA, Mann-Whitney U test and Studentʹs t-test. Results. The gallium alloy showed setting expansion which was greater than that for the other amalgam and greater than the upper limit set by the ISO standard. For other properties, gallium alloy performed as well as, and in the case of creep, was superior to that of the amalgam. Significance. The gallium alloy proved difficult to manipulate even when using the PTFE coated instruments recommended by the manufacturer. It is suggested that while the material may prove to be a viable alternative to conventional dental amalgam, a considerable improvement in its handling characteristics would be required before it would gain widespread acceptance for clinical use.