U. Ripamonti et al., INDUCTION OF CEMENTOGENESIS BY RECOMBINANT HUMAN OSTEOGENIC PROTEIN-1(HOP-1 BMP-7) IN THE BABOON (PAPIO-URSINUS)/, Archives of oral biology, 41(1), 1996, pp. 121-126
Recombinant human osteogenic protein-1 (hOP-1), a member of the bone m
orphogenetic protein family, was examined for its efficacy in periodon
tal regeneration. Twelve furcation defects, surgically prepared in the
first and second mandibular molars, were treated with bovine insolubl
e collagenous matrix in conjunction with 0.0 (control), 100 and 500 mu
g of recombinant hOP-1 per g of matrix. After 60 days of healing, his
tological and histometric analyses on serial, undemineralized sections
cut at 7 mu m showed substantial cementogenesis on the exposed dentin
e of furcations treated with both doses of hOP-1 (p < 0.01 vs control)
. Foci of nascent mineralization were seen within the newly deposited
cementoid along the coronal areas of hOP-1-treated defects. Within the
furcations, there were substantial amounts of residual collagenous ca
rrier, interspersed with a mineralized matrix having histological feat
ures of cementum. This mineralized cementum-like material was predomin
antly deposited around the carrier, and blended into newly formed ceme
ntum along the root surfaces. In the apical area, the cementum-like ma
terial and the remaining alveolar bony housing were not connected; ind
eed the two components were separated by a fibrovascular tissue that h
ad numerous features of the periodontal ligament space. Formation and
insertion of Sharpey's fibres into newly formed root cementum were als
o observed. It is likely that the expression of specific cell phenotyp
es by hOP-1 is regulated, in part, by the extracellular matrix microen
vironment, including dentine. Thus, exposed dentine, in the presence o
f exogenous hOP-1 at the doses tested, may preferentially modulate the
expression of the cementogenic phenotype. These findings in a non-hum
an primate show that hOP-1, at the doses tested, induced cementogenesi
s on surgically denuded root surfaces, indicating a specific function
during repair and regeneration of periodontal tissues.