Scanning electron microscope study of marginal adaptation of amalgam in restoration finishing techniques

Voids and gaps between the surfaces of the amalgam and the cavity preparation were apparent in the carved and the polished samples. These spaces in the burnished specimens were filled with an amorphous bulk of amalgam apparently caused by the burnishing process. Since the margins of burnished amalgam restorations have been shown to leak less than those of carved and polished specimens, it is hypothesized that this is due to the improved marginal adaptation attained through the burnishing process.