Reparo ósseo utilizando enxerto de matriz orgânica bovina: análise histológica em calvária de coelhos

Abstract

Xenogenic graft of bone origin has been used to favor bone regeneration and to reduce autogenous bone needs. The purpose of this study was to evaluate the bone repair induced by particulate bovine organic bone grafted in rabbit calvaria. Two standardized bone defects were prepared in both parietal of 20 adult rabbits. The defects were filled by clot, autograft, medular organic bovine bone or cortical organic bovine bone. Thirty days following surgery animals were killed; the calvaria were removed, fixed in formol, demineralized in EDTA and embedded in paraffin. Histological sections were stained in HE or Mallory Trichrome and analyzed by light microscope. On group filled with clot only the half of the defect was repaired by new bone tissue, which was formed from lesion border, central area presented cellular connective tissue. In defects filled with autograft almost all defect was repaired by bone tissue. Defects grafted with medular or cortical bovine bone exhibited near ¼ of defect filled by bone tissue, formed from border, with central area occupied by fibrous connective tissue. Almost all xenogenic grafts were reabsorbed, remaining few fragments that were associated to foreign body giant cell reaction and few showing bone neoformation around. Therefore, the graft of organic bovine bone, medular or cortical, used in an isolated way, didn't favor the process of bone repair.