Journal of Dental Research, Vol 72, 72-77, Copyright © 1993 by International & American Associations for Dental Research Online Journals
The determination of ionic bonding interactions of N-phenyl glycine and N-(2-hydroxy-3-methacryloxypropyl)-N-phenyl glycine as measured by carbon-13 NMR analysis
L. E. Wolinsky, R. W. Armstrong and R. R. Seghi
School of Dentistry, University of California, Section of Oral Biology, Los Angeles 90024-1668.
The purpose of the present investigation was to determine whether
high-resolution carbon-13 nuclear magnetic resonance could be utilized for
detection of ionic bonding interactions of NPG and NPG-GMA with selected
inorganic cations. The C1-carbonyl carbon of NPG and NPG-GMA were labeled
with 13C to help magnify the spectral response signal. The labeled monomers
were allowed to react with Ca(OH)2 and LiOH. The C-13 carbonyl resonance
was observed by solution- and solid-state NMR. The interaction of the
cations in solution and on a powered glass support resulted in a downfield
chemical shift of about 2-5 ppm, indicating the presence of a chemical
interaction between the monomer and the cations. The reaction of the
monomers with the solid substrates of hydroxyapatite, and bovine dentin did
not result in a significant downfield shift in the carbonyl resonance. The
results provide evidence that high-resolution nuclear magnetic resonance
can be used for evaluation of chemical bonding interactions of dental
adhesives with inorganic ions.
