Repair and regeneration in endodontics
L. M. Lin & P. A. Rosenberg
Department of Endodontics, New York University College of Dentistry, New York, NY, USA
The ideal objective of treatment of established diseases,
including irreversible pulpitis and apical periodontitis,
is to achieve wound healing. Wound healing can result
in repair or regeneration. The ultimate goal of wound
healing is to restore the original architecture and
biological function of the injured tissue or organ.
Although humans are equipped with powerful innate
and adaptive immune defence mechanisms, many
intrinsic and extrinsic factors can affect wound healing.
Complete regeneration following injury in humans can
occur only in the pre-natal foetus within 24 weeks of
gestation. Post-natal wounds including irreversible
pulpitis or apical periodontitis always heal by repair
or by a combination of repair and regeneration.
Somatic cells, such as fibroblasts, macrophages,
cementoblasts and osteoblasts, in the pulp and periapi-
cal tissues have limited potential for regeneration
following injury and lack of telomerase. Wound healing although pulpal and periapical disease can be caused
by traumatic injury, physical insult, chemical irrita-
tion or periodontal disease, microbial infection is the
primary aetiology (Kakehashi et al. 1965, Nair 1997,
2004). The ideal objective of the treatment of estab-
lished diseases, including irreversible pulpitis and
apical periodontitis, is to achieve wound healing of irreversible pulpitis and apical periodontitis requires
recruitment and differentiation of progenitor/stem cells
into tissue-committed somatic cells. Stem cell differen-
tiation is regulated by intrinsic factors and extrinsic
micro-environmental cues. Functionality of stem cells
appears to show an age-related decline because of the
change in intrinsic properties and diminished signals
within the extrinsic local and systemic environment
that modulate the function of stem cells or their
progeny. Infection induces an immuno-inflammatory
response and tissue destruction, which hinders the
potential of tissue regeneration. Therefore, prevention,
early detection and treatment of inflammation/infec-
tion of pulpal and periapical disease can enhance
regeneration and minimize the repair of pulpal and
periapical tissues after endodontic therapy.
Keywords: nonvital pulp therapy, post-natal wound
healing, pre-natal wound healing, progenitor/stem
cells, vital pulp therapy.
