Dentin resorption and cementum-like tissue formation by bone morphogenetic protein application.
OBJECTIVE
Recent studies have shown that bone morphogenetic protein-2 (BMP-2) stimulates mineralization and osteoclast differentiation. Osteoclastic resorption by BMP-2 application may play an important role in the regulation of new cementum-like tissue formation on the dentin surfaces. Therefore, this study aimed to examine the effect of BMP-2 application on dentin resorption and cementum-like tissue formation at the dentin surfaces.


METHODS
Seventy-two flat dentin blocks were prepared from rat roots and treated with 24% EDTA. Each block was assigned to group 0, group 100, or group 400, and immersed correspondingly in 0, 100, or 400 microg/ml BMP-2. The dentin blocks were then implanted into palatal connective tissue of rats, and specimens were prepared 2, 4 and 8 wk after surgery for histologic and histomorphometric analyses.


RESULTS
BMP-2 caused a dose-dependent increase in dentin resorption by osteoclastic cells. New cementum-like tissue was randomly formed on parts of the nonresorbed and resorbed dentin surfaces in groups 100 and 400. Dentin resorption in groups 100 and 400 was significantly greater than group 0 (p < 0.01). However, at 8 wk, new cementum-like tissue formed in 41.8% of group 100, as compared with 16.2% of group 400 (p < 0.05).


CONCLUSIONS
Dentin resorption was stimulated by a high dose of BMP-2, and cementum-like tissue was induced by a low dose of BMP-2, effectively suggesting that BMP-2 application, at an appropriate dose, to a dentin surface may enhance periodontal regeneration.
Miyaji
H
H
Department of Periodontology and Endodontology, Division of Oral Health Science, Hokkaido University Graduate School of Dental Medicine, Sapporo, Japan. miyaji@den.hokudai.ac.jp
Sugaya
T
T
Kato
K
K
Kawamura
N
N
Tsuji
H
H
Kawanami
M
M
D000818:Animals; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology*; D025021:Cementogenesis / Q000187:drug effects*; D003804:Dentin / Q000187:drug effects* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D007124:Immunoenzyme Techniques; D008297:Male; D010010:Osteoclasts / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D012038:Regeneration / Q000187:drug effects*; D012391:Root Resorption / Q000378:metabolism*; D018709:Statistics, Nonparametric; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
C525720:Bmp2 protein, rat; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D016212:Transforming Growth Factor beta