Journal of Dental Research, Vol 75, 1971-1978, Copyright © 1996 by International & American Associations for Dental Research Online Journals
An in vitro model of human dental pulp repair
H. Magloire, A. Joffre and F. Bleicher
Laboratoire du Developpement des Tissus Dentaires, Faculte d'Odontologie, Lyon, France.
Pulp tissue responds to dentin injury by laying down reactionary dentin
secreted by existing odontoblasts or reparative dentin elaborated by
odontoblast-like cells that differentiated from precursor cells in the
absence of inner dental epithelium and basement membrane. Furthermore,
growth factors or active dentin matrix components are fundamental signals
involved in odontoblast differentiation. In vitro, dental pulp cells
cultured under various conditions are able to express typical markers of
differentiation, but no culture system can re-create pulp response to
dentin drilling. This paper reports the behavior of thick slices from human
teeth drilled immediately after extraction and cultured from 3 days to 1
month. Results show that the damaged pulp beneath the cavity is able to
develop, in vitro, some typical aspects correlated to tissue healing,
evidenced by cell proliferation (BrdU-positive cells), neovascularization
(positive with antitype-IV collagen antibodies), and the presence of
functional (3H proline-positive) cuboidal cells close to the injured area.
After 30 days of culture, elongated spindle-shaped cells can be seen
aligned along the edges of the relevant dentin walls, whereas sound
functional odontoblasts are well-preserved beneath healthy areas. This
tissue recovery leads us to believe that such a culture model will be a
useful system for testing factors regulating pulp repair.
