Critical Reviews in Oral Biology & Medicine, Vol 8, 154-163, Copyright © 1997 by International & American Associations for Dental Research
Tissue engineering, morphogenesis, and regeneration of the periodontal tissues by bone morphogenetic proteins
U. Ripamonti and A. H. Reddi
Bone Research Laboratory, MRC/University of the Witwatersrand, Medical School, Johannesburg, South Africa.
Tissue engineering is the emerging field of science developing techniques
for fabrication of new tissues for replacement based on principles of cell
and developmental biology and biomaterials. Morphogenesis is the cascade of
pattern formation and the attainment of form of the various organs and the
organism as a whole. The periodontium consist of the periodontal ligament,
cementum, and alveolar bone. Bone has considerable potential for
regeneration and therefore is a prototypic model for tissue engineering.
The three main ingredients for tissue engineering are regulatory signals,
responding stem cells, and extracellular matrix. Recent advances in
molecular biology of the bone morphogenetic proteins (BMPs) have set the
stage for tissue engineering of bone and related tissues, including the
periodontium. Bone-derived BMPs, with a collagenous matrix as carrier,
induced cementum and alveolar bone regeneration in surgically created
furcation defects in the primate. It is noteworthy that there was
morphogenesis of periodontal ligament and a faithful insertion of Sharpey's
fibers into cementum. In the same furcation model, recombinant human
osteogenic protein-1 (rhOP-1, also known as BMP-7), in conjunction with the
collagenous carrier, induced extensive cementogenesis with insertion of
Sharpey's fibers into the newly formed cementum. The observation that BMPs
induce cementogenesis and periodontal ligament formation indicates that
these proteins may have multiple functions in vivo not limited to cartilage
and bone induction. The rapid advances in the molecular biology of BMPs and
their receptors bode well for novel strategies to engineer the regeneration
of the periodontal tissues.
