Journal of Dental Research, Vol 72, 558-565, Copyright © 1993 by International & American Associations for Dental Research Online Journals
Solubility parameters, fractional polarities, and bond strengths of some intermediary resins used in dentin bonding
E. Asmussen and S. Uno
Department of Dental Materials, School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Denmark.
An effective bonding of resin composites to dentin is generally preceded by
a conditioning of the surface of the dentin. Previous studies have
indicated that the intermediary or adhesive resin should have specific
wetting characteristics matching those of the conditioned dentin, in order
that optimum bonding can be ensured. The wetting characteristics may be
expressed in terms of solubility parameter (delta) and polarity (p) of the
resin. The aims of the present study were to determine these variables for
a number of compounds used in adhesive resins and to investigate the
effects of delta and p on the shear bond strength to dentin. Solubility
parameters were obtained according to the method of Small. Fractional
polarities were calculated on the basis of measurements of refractive index
and dielectric constant of the resins. In the measurements of bond
strength, Scotchprep, EDTA + Gluma, or Al2Ox3/glycine were used as dentin
conditioners in combination with intermediary resins having various delta
and p. For each conditioner, the shear bond strength (BS) could be
"explained" by an exponential expression of the form BS = e(a + bx), where
x = (delta + cp + d)2, and where a-d are constants depending on the
conditioned dentin. It may be concluded that solubility parameter and
polarity of the intermediary resins are important variables in the process
of bonding to dentin.
