Biomedical Engineering Reference
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from rabbit DDM, and Bessho, et al [9] secured new bone formation
in situ
by BMP from human
DDM. Furthermore, Ike and Urist [10] used dentin root matrix as a carrier of recombinant
human bone morphogenetic protein (rhBMP). Starting in 1993, we developed bone graft
materials using human teeth with which we conducted experimental studies [11-22]. In 2008,
we developed an autogenous tooth bone graft material (AutoBT; Korea Tooth Bank Co., Seoul,
Korea) from extracted teeth prepared as powder and grafted it to the donor patient himself.
The mineral components of autogenous tooth bone graft materials have 4 stages (types) of
calcium phosphate (HA, TCP, OCP, and ACP). Under scanning electron microscopic exami‐
nation, HA crystalline structures and collagen fibers around the dentinal tubules were
detected. Short-term clinical studies reported that, even when wounds became dehiscent, the
bone graft materials were not infected, and good secondary healing was achieved [3,23].
2. Osteoinduction of AutoBT
Many researchers have examined tooth dentin as a potential carrier for human proteins and
as grafting material because its biological composition is very similar to that of alveolar bone
[9, 24-28]. Both tooth and alveolar bone are derived from neural crest cells and are made up of
the same Type I collagen. Furthermore, dentin contains BMPs, which induce bone formation
and noncollagenous proteins such as osteocalcin, osteonectin, and dentin phosphoprotein [29,
30]. Since its investigation by Urist in 1965, BMP has been widely studied and used in clinical
applications [31]. As a result, Yeoman and Urist, et al (1967) and Bang and Urist, et al (1967)
showed the osteoinductivity of rabbit DDM by BMP [32, 33]. Bessho, et al extracted BMP from
bone matrix, dentin matrix, and wound tissue after extracting teeth from rabbits. Each BMP
was confirmed to have induced the formation of new bone when xenogenic implantation was
performed [9]. Bessho, et al extracted human dentin matrix containing 4mol/L guanidine HC1
and refined it into liquid chromatography and found out based on SDS-PAGE and IEF that
purified BMP is homogenous, inducing the formation of new bone within 3 weeks of implan‐
tation in muscle pouches in Wistar rats. Dentin matrix-derived BMP is not exactly same as
bone matrix-derived BMP, but they are very similar. In other words, two types of BMP exhibit
the same action in the body [34]. The organic component accounts for about 20% of dentin
weight and mostly consists of type I collagen. Moreover, it was proven to have BMP promoting
cartilage and bone formation, and differentiating undifferentiated mesenchymal stem cells
into chondrocytes and osteogenic cells [30, 35-37]. Noncollagenous proteins of dentin such as
osteocalcin, osteonectin, phosphoprotein, and sialoprotein are known to be involved in bone
calcification [38,39].
Patterns of matrix protein in teeth must have osteoinductive potential even though it does not
perfectly match the protein in alveolar bone. Moreover, the apatite in teeth has long been
known to play the role of protecting proteins [40]. According to Boden, et al, LIM mineraliza‐
tion protein 1 (LMP-1) is an essential positive regulator of osteoblast differentiation and
maturation and bone formation [41]. Wang, et al found that LIM-1 was expressed primarily in
predentin, odontoblasts, and endothelial cells of the blood vessels of teeth [42].
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