"Avaliação histológica da reparação óssea induzida por osso bovino desmineralizado, em defeitos bicorticais na mandíbulas de ratos, com ou sem membranas de colágeno cálcicas" / Histological evaluation of bone healing induced by demineralized bovine bone, in bicortical defects of rat mandibles, with or without calcic collagen membranes




The use of demineralized bone (DB), in special from bovine source, has been evaluated extensively in experimental models; however, doubts exist if there is sufficient quantity of bone morphogenetic proteins (BMP) to induce the bone repairing. The combination of membranes avoids the encapsulating of DB particles and also it could prevent the early dissolution of the few BMPs present in the DB. The aim of this study was to carry out a histological evaluation of the bone repairing induced by DB on defects created in the rat mandibles, and the effect of using resorbable collagen membranes impregnated with calcium salts. The study involves 25 Wistar rats, in which DB discs were employed to fill bicortical defects in the region of mandibular angle; at the left side, membranes recovered the lingual and buccal side. The animals were divided into groups of five individuals each one and then killed after three, 10, 20, 30 and 60 postoperative days. Within first 20 days, the histological analysis revealed intense bone proliferation in the two bone ends, buccal as much lingual, and it is also probable the proliferation has occurred all around of the circular margin defect. However, from 30 days, there was an inversion in the histological findings: the inflammatory reaction until then moderate became na intense inflammatory infiltrate that was involving the DB, with total absence of the membrane, and then reducing the intensity at 60-days group, which presented remnants of foreign body reaction enveloping the DB, without new bone filling of the defect. From these results, it can conclude by the presence of BMPs, responsible by the great initial bone proliferation; the physical form of DB in sheets, of which discs were prepared, seemed to have prevented resorption of the remnant bone matrix and raised foreign body reaction. Finally, the calcium-collagen membrane had little effect in the bone proliferation, raising moderate inflammatory infiltrate around it.


ratos mandíbula bone transplantation rats curativos biológicos regeneração óssea biological dressings mandible transplante ósseo bone regeneration

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