Journal of Dental Research, Vol 71, 1498-1502, Copyright © 1992 by International & American Associations for Dental Research Online Journals
Solubilization of dentin matrix collagen in situ
A. J. Van Strijp, B. Klont and J. M. Ten Cate
Department of Cariology and Endodontology, Academic Centre for Dentistry Amsterdam (ACTA), The Netherlands.
The effects of the oral environment on dentin matrix collagen were studied.
In the partial prostheses of 12 participants, two completely demineralized
dentin specimens were mounted covered by a Dacron gauze. After an
experimental period of seven weeks, the specimens were transferred to a
trypsin-containing buffer for determination of the amount of denatured
collagen. Subsequently, the specimens were incubated with a bacterial
collagenase for assessment of the amount of collagen. After the intra-oral
exposure, there was a collagen loss varying between 1 and 47 wt%. This
variation might be due to differences in proteolytic activity of the
colonizing microflora. After exposure to the oral environment, only about
0.5 wt% of the available collagen was trypsin-degradable. This indicates a
rapid solubilization of the denatured collagen from the specimens into the
oral cavity. A separate group of specimens was examined by light microscopy
and transmission electron microscopy. Various degrees of breakdown could be
discerned. Some experimental specimens showed loss of surface integrity and
tubules heavily infected with different types of micro-organisms. The
lumens of the tubules were enlarged, sometimes creating caverns as a result
of the loss of the intertubular collagenous matrix.
