Abstract
The bone tissue has a great regenerative potential, with ability to completely restore its structure and original functions. In some situations, though, bone defects cannot be self-repaired, thus requiring the use of grafts for a correct treatment and good prognosis. This work aimed at microscopically analyzing the effect of the particle size of demineralized bovine cancellous bone matrix in micro and macrogranular forms on the repair of bone defects in femurs of rabbits, with blood clot used as control. At 1, 3 and 6 months after implantation of the materials, the animals were killed and the anatomic specimens were removed. A foreign body-type granulomatous reaction containing macrophages and multinucleated giant cells in contact with the implanted particles was observed. These results suggest a failure in demineralization and/or interruption of the antigenic potential during production of the biomaterial. It is concluded that the size of the particles did not influence the evolution of the repair process of bone defects, acting only as bone-filler substances, and that the material implanted should be improved by quality control during production, since it may represent a good alternative for bone graft.
Highlights
The bone tissue, the main component of the skeleton, has the function of protecting and supporting the vital organs because of its stiffness and resistance
The advent of new xenogenic biomaterials, as bovine bone, which behave as repair promoters and carriers of bone induction factors, seems to represent the future of reconstruction of bone defects; there has been a constant concern with the presentation of these biomaterials as to shape and size
In the experimental groups evaluated, at the three study periods, the presence of chronic inflammatory infiltrate was constant, usually discrete, with predominance of macrophages and multinucleated giant cells, characterizing a true foreign body granulomatous reaction, containing scattered lymphocytes, suggesting that the particles of demineralized bovine bone matrix possibly present a low antigenic character in the rabbit, as already observed in other studies[12]. Another finding that reinforces this statement are the studies on guinea pigs’ skulls[11], using particles of demineralized bovine bone matrix, blood clot and covered with lyophilized cortical bovine bone membrane, whose cellular response after a period of three to six months revealed new bone formation and absorption of the membrane by action of mononuclear cells similar to fibroblasts, which invade the interior of the membrane through porosities
Summary
The bone tissue, the main component of the skeleton, has the function of protecting and supporting the vital organs because of its stiffness and resistance. Its capacity to be restored is related to the ability of growing factors in directing the stem cells for condrogenesis and osteogenesis, and to the role played by mechanical forces that stimulate bone remodeling. The advent of new xenogenic biomaterials, as bovine bone, which behave as repair promoters and carriers of bone induction factors, seems to represent the future of reconstruction of bone defects; there has been a constant concern with the presentation of these biomaterials as to shape and size. The role of carriers of bone induction factors can be potentially played by bovine cancellous or cortical bone, either macro or microgranular, deproteinized or demineralized, as already shown in clinical studies. Besides supplying a supportive structure and bone conduction, it can provide a high content of calcium and phosphorus, essential for the new formation of bone tissue[3,8]. The actual role of the size of these bonesubstitute materials in relation to the cellular answer of the host is yet very controversial
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
