[Resistance to traction forces in different brands of amalgam]

In a previous study the initial tensile strength of several dental amalgams after 15 minutes has been investigated. The present study scrutinized a large number of dental amalgams for the tensile strength after 15 minutes up to 60 minutes. All the dental amalgam specimens used in this study were prepared according to A.D.A. specification no. 1. The results obtained from this study show that out of the twenty three dental amalgams only approximately the half conformed to the minimum value of 2.0 MN/m2 as required for the tensile strength after 15 minutes by A.D.A. specification no. 1. Contrary to the results obtained by other investigators, the dental amalgam obtained from the spherical type of alloys does not acquire a superior initial strength in comparison with those from the conventional types of amalgam alloys. In this study the new dental amalgam alloy Indiloy (n.z.) (Shofu Corporation, Japan) demonstrated a superior tensile strength for all the testing times. If the tensile strength after 15 minutes is taken as a selection criterion, the five best alloys in this investigation are Indiloy (n.z.), Optalloy II, Micro II, Revalloy and Cavex SF. If the previous study is considered likewise. Dispersalloy (fast setting form) should be taken into account as well.