Journal of Dental Research, Vol 73, 1657-1662, Copyright © 1994 by International & American Associations for Dental Research Online Journals
Quantity of remaining double bonds of propanal-containing resins
A. Peutzfeldt
Department of Dental Materials, School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Denmark.
Improved mechanical properties of resin composites have been reported to be
a consequence of the addition of aldehyde to the resins. The objective of
the present study was to examine whether this improvement could be
attributed to an increased degree of conversion of double bonds. For this
purpose, propanal was added to monomer mixtures, which were then made
light-curing. The monomer mixtures were varied with respect to monomer
composition and content of propanal. The quantity of remaining double bonds
was determined by means of transmission infrared spectra of the resins
recorded before and after wet or dry storage for one week. The addition of
propanal resulted in a decrease in the quantity of remaining double bonds
by as much as 89% as compared with the mixtures without propanal. Negative
correlations of statistical significance were found between the content of
propanal and quantity of remaining double bonds in BISGMA:TEGDMA-based as
well as in UEDMA:HEMA-based resins for both modes of storage. Significant
negative correlations were found between the quantity of remaining double
bonds and the previously determined mechanical properties.
