Journal of Dental Research, Vol 72, 56-61, Copyright © 1993 by International & American Associations for Dental Research Online Journals
Influence of shearing action of food on contact stress and subsequent wear of stress-bearing composites
P. Pallav, A. J. de Gee, A. Werner and C. L. Davidson
ACTA (Academic Centre for Dentistry Amsterdam), Department of Dental Materials Science, The Netherlands.
The influence of sliding action of the antagonist on occlusal three-body
wear of composites and an amalgam was investigated in vitro by gradual
change in the distance between the opposing substrates. When the distance
was decreased from 10 microns to approximately 3 microns, wear increased
significantly by a factor of two to three and was exclusively of erosive
nature. At a slurry-film thickness of approximately 1 micron, direct
contacts between the antagonist and protruding composite filler particles
started to occur. This consequently slowed the erosive wear. Ultimately,
direct contact phenomena predominated, decreasing the wear rate of the
various materials to different degrees. Loss of material due to subsurface
fatigue could not be demonstrated with a contact pressure of 45 MPa at
which the experiments were performed. From this study, it can be concluded
that minor alterations of the food-film thickness at the contact areas
result in considerable changes in wear rates and wear-rate ranking of
composite materials, which may partly explain inconsistencies among
clinical trials.
