Journal of Dental Research, Vol 67, 1386-1391, Copyright © 1988 by International & American Associations for Dental Research Online Journals
The effects of partial demineralization and fibronectin on migration and growth of gingival epithelial cells on cementum in vitro
S. Pitaru, M. Hekmati, S. Geiger and N. Savion
Department of Oral Biology, Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Israel.
The capacity of mineralized cementum to support epithelial cell migration
and growth and the effect that fibronectin and partial demineralization of
cementum have on these processes were assessed in vitro. Dog gingival
explants, 1 X 2 mm, were cultured on the cementum surfaces of pig root
pieces in a defined medium consisting of DMEM and F12 (1V/1V), transferrin,
insulin, epidermal growth factor, cortisone, selenium, and high-density
lipoprotein. Sixty root pieces were divided into four equal groups
according to the treatment: (1) untreated mineralized cementum; (2) treated
with 5 micrograms of fibronectin; (3) partially demineralized in 18% EDTA
for 30 min; and (4) both partially demineralized and fibronectin-treated as
above. Epithelial cell migration and growth on each of the four differently
treated cementum surfaces were assessed histomorphometrically by means of
scanning electron microscopy. The defined culture medium supported the
selective migration and growth of epithelial cells from the gingival
explants onto the mineralized cementum. This was confirmed by the positive
immunostaining of these cells with antikeratin antibodies. Partial
demineralization of cementum inhibited epithelial migration and growth by
83% and 91%, respectively. Fibronectin treatment did not affect epithelial
cell migration and growth on mineralized cementum, but it decreased the
degree of epithelial cell migration and growth inhibition on partially
demineralized cementum to 57% and 43%, respectively. The results indicate
that: (i) mineralized cementum may consist of components that are
recognized by gingival epithelial cells and support their migration and
growth in vitro; (ii) these components can be removed by demineralization;
and (iii) fibronectin partially restores epithelial cell migration and
growth on partial demineralized cementum in vitro.
