Journal of Dental Research, Vol 64, 147-150, Copyright © 1985 by International & American Associations for Dental Research Online Journals
Time-dependent deformation of composite restorative materials in compression
D. J. Cock and D. C. Watts
The strain of six composite resins, including microfine and conventional
types, has been measured in compression as a function of time. Compressive
loads have been used in separate experiments to produce a wide range of
applied stress in samples of clinically-appropriate size. The magnitude of
visco-elastic response generally decreases with increasing % of filler in
the composite. Additionally, the very substantial linear strain, up to 20%,
observed in some microfine composites suggests the visco-elastic
deformation of both organic filler, as well as resin matrix, at high stress
levels. Caution is therefore indicated with regard to the clinical use of
microfine restorative materials in high-stress-bearing situations.
