Journal of Dental Research, Vol 69, 1236-1239, Copyright © 1990 by International & American Associations for Dental Research Online Journals
Amine-induced polymerization of aqueous HEMA/aldehyde during action as a dentin bonding agent
E. C. Munksgaard
Department of Dental Materials & Technology, Royal Dental College, Copenhagen N, Denmark.
Aqueous mixtures of HEMA with glutaraldehyde or propionaldehyde polymerize
by addition of catalytic amounts of amines or amino acids. The maximal
reaction velocity of the transformation of HEMA/glutaraldehyde with glycine
was obtained at pH 0.8. Kinetic data suggested a second-order reaction
between glutaraldehyde and glycine, and solubility data suggested formation
of a cross-linked polymer. A relatively high bond strength between dentin
and resin composite was obtained by pre-treatment of dentin with Gluma (35%
HEMA, 5% glutaraldehyde in water) adjusted to pH 1.0 with hydrochloric
acid. It is proposed that on application of Gluma, amino-group-containing
substances in dentin react with glutaraldehyde and start the formation of a
HEMA polymer. This product may be cross-linked by an alpha,beta-unsaturated
glutaraldehyde aldol condensation product and may bond to dentin by
aldehyde fixation to dentin proteins. Resin composite will bond to this
product by copolymerization.
