Molecular characterisation of odontoblast during primary, secondary ...

Introduction
superficial cells move to the centre of the injury regenerating and repairing the
tissue and allowing its reorganisation.
Odontoblasts are differentiated post-mitotic cells and are unable to divide to
produce new secretory cells. When these cells are lost, cellular replacement occurs
which involves stem or progenitor cells resident in the pulp (Fitzgerald 1979;
Fitzgerald, Chiego et al. 1990) (Figure 11). Following pulp exposure, and after
placement of an appropriate material, a dentine bridge is formed in a few weeks
(Figure 12) by new odontoblast-like cells. The origin of these odontoblast-like cells in
the dentine pulp healing process is not clearly established. Several authors believe
that these processes are likely to be the same as those involved in tooth development
(Smith and Lesot 2001; Mitsiadis and Rahiotis 2004), however, the derivation of these
cells is still unclear with an origin from outside the tooth via the vasculature cannot
be excluded.
Figure 11 : Dentine bridge formation five weeks after pulp capping with MTA® in a
mouse first molar (frontal semi-thin section, x50 magnification, methylene blue –
Blue Azur II) Scale bar=200µm.
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