Microprobe Analysis of a High Cu Amalgam Alloy

Microprobe and X-ray diffraction analysis of a high Cu spherical alloy showed a minute dis-persion of Cu,Sn, y(Ag3Sn), and 13(Ag-Sn). The Sn-Hg (ys) phase was not detected in amalgams made from this alloy. The reaction phases were found to be y, (Ag-Hg) and y(Cu6Sn-).-American Dental Association's Specification no. 1. § The specimens were stored for one week at 37 C and then mounted and polished for microprobe analysis. # The alloy alone was also evaluated in the as-received and annealed (425 C, one week) conditions using both microprobe and X-ray diffraction analysis. Recently, Asgar ' described a new amalgam alloy that contains 60 % Ag, 27 % Sn, and 13% Cu. * This alloy was described as consisting of spherical particles having a "single composi-tion. " Using microprobe analysis, it was found that after a short period of time, amalgam made from this alloy did not contain any Sn-Hg (72) phase and that a Cu-Sn reaction product was present. ' Because of the inno-vative nature of this alloy, it was considered desirable to conduct further microprobe analy-ses to clarify certain questions raised concern-ing this alloy and its amalgam. Materials and Methods The alloyt for this study was supplied by Dr. Asgar. Amalgam specimens measuring 4 mm in diameter by 8 mm long were made using the recommended conditions of 42 % Hg, nine seconds trituration without a pestle in a mechanical amalgamator,t and the mechani-cal method of condensation described in th