Long‐term phase changes in dental amalgam after setting

The integrated peak intensities of certain reflections of the γ, γ1 and γ2 phase of six dental amalgams at a mercury content of 45 wt% were selected and their dependence on the annealing time (1 < t < 140 days) at 37°C was determined. Also the overall changes in phase composition were studied qualitatively by means of the peak heights of all phases found in the X‐ray patterns of these amalgams at different annealing times. The γ2 phase content did not seem to depend on the annealing time. It was established also that the γ and γ1 phase contents of these dental amalgams decrease with increasing annealing time at 37°C whereas the quantity of another phase, probably the ternary β phase increases with increasing annealing time.