Brittle fracture of dental amalgam.

The brittleness of dental amalgam limits its use to sites in which tensile stresses can be kept at a minimum. If the cause for the brittleness could be ascertained, then an approach to correct this problem could be devised. Physical properties of metals are ultimately manifested in, and can be explained by, their microstructure. Through the work of several researchers,1-3 means of identifying the phases present in the microstructure have been developed. In this study, the etching solutions developed by Schmitt1 and Wing2 were employed. The phases present in amalgam, as shown by these chemical etches, are identified as 'y, yri, and 72. The