Estudo imunoistoquimico da incorporação de enxerto alogeno com proteina morfogenetica do osso-2 na mandibula de rato

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

Large bone defects can be managed by autogenous graft; however limitations in this source have induced research for new materials to replace autogenous graft. The incorporation of autoclaved alogenous bone graft associated to recombinant human bone morphogenetic protein 2 (rhBMP-2) was the objective of this study. The study animals were 75 Wistar rats distributted into 3 groups with 25 animals. The rats were submited to a mandibular critical size defect to be treated with autogenous graft from iliac in control group while experimental groups used autoclaved alogenous bone, with or without rhBMP-2. The animals were sacrificed after 1, 7, 14, 21 and 28 days, the mandible radoigraphed, decalcified, stainned for heamatoxilin and eosin and immunohistochemistry for Indian hedgehog (Ihh) and Sonic hedgehog (Shh) and osteopontin (OPN). Radiographic image was submited to optical densitometric avaliation. After 28 days microscopic examination showed almost fully incorporated graft in control group, but in alogenous group without rhBMP-2 there was little incorporation and bone neoformation without bony union between mandible and graft. The use of rhBMP-2 caused an intense osteoinduction bonding mandible and graft after 7 days. After 28 days the incorporation process was similar to that seen in control group. Expression of Shh and Ihh was in the same pattern, with positive chondrocytes-like cells, fibroblast-like cells and osteoblasts near bone neoformation. OPN marker showed positive areas associated to osteocytes, osteoblasts, reversal lines and osteoid matrix. Optical densitometry showed statistically significative results inside rhBMP-2 treated group. This study showed that rhBMP-2 associated to autoclaved alogenous graft is osteoinductive. The Shh and Ihh proteins were expressed during graft incorporation, maybe playing an important role in the bone reparation signalling pathway

ASSUNTO(S)

rato ossos - enxerto mandibula

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