Journal of Dental Research, Vol 60, 1966-1971, Copyright © 1981 by International & American Associations for Dental Research Online Journals
Marginal adaptation of BIS-GMA-based composites containing various diluents
G. M. Brauer, D. M. Dulik, H. N. Hughes, K. Dermann and N. W. Rupp
The aim of this study was to determine how otherwise acceptable diluent
monomers affect the marginal adaptation of BIS-GMA-based composites. Based
on the results of the investigation, the following conclusions can be
drawn: 1. Addition to dimethacrylate diluents containing (CH2) recurring
units generally yields composites having better marginal adaptation than do
those containing (CH2 CH2 O) groups. Best marginal adaptation for a single
diluent is obtained for compositions using 1, 4 and 1, 10-polymethylene
glycol dimethacrylate as diluent. 2. Marginal adaptation is improved on
lowering the diluent concentration. Optimum adaptation will be obtained for
a formulation containing a minimum percentage of diluent with clinically
acceptable working properties. 3. Volume changes on temperature cycling
resulting from differences in thermal expansion coefficients of composites
do not effect the marginal integrity as much as does curing shrinkage.
