Journal of Dental Research, Vol 68, 1545-1549, Copyright © 1989 by International & American Associations for Dental Research Online Journals
Maximum bond strength of dental luting cement to amalgam alloy
P. Mojon, E. B. Hawbolt, M. I. MacEntee and U. C. Belser
Department of Clinical Dental Sciences, University of British Columbia, Vancouver, Canada.
Although dental amalgam is used frequently under artificial crowns for
restoration of severely damaged teeth, there is little information
available on the bond between luting cements and this alloy. This study was
designed for determination of the strength of the bond between a dental
amalgam alloy and three crown-luting cements. Cylinders of dental amalgam
were joined in pairs, with use of a zinc-phosphate, a glass-ionomer, and an
acrylic-adhesive resin cement. The tensile-fracture stress of 45 samples of
each cement was measured with a universal testing machine, and subjected to
a Weibull analysis. The fractured surfaces were examined under low
magnification with use of a light microscope, and at low and high
magnifications with use of a scanning electron microscope, for evaluation
of the appearance of the fractured joints. The Weibull analysis
demonstrated that the adhesive resin cement provided a stronger and more
predictable bond than either the zinc-phosphate or the glass-ionomer
cement. The appearance of the fractured surfaces gave no indication of the
strength of the joints, a feature that is common to brittle materials. The
results suggest that crowns placed on teeth offering a large amalgam-alloy
surface could be retained more predictably with an adhesive resin cement.
