Quantificação do potencial osteogênico in vivo do osso autógeno + células osteoblásticas carreadas por uma biocerâmica composta de hidroxiapatita e fosfato tricálcio-β: Estudo qualitativo e quantitativo em microscopia de luz e eletrônica de varredura
A Abs bstra ract t MACEDO, R.M. Quantification of the osteogenic potential in vivo of autogenous bone + osteoblastic cells carried by a bioceramic consisting of hydroxyapatite and β-tricalcium phosphate: A qualitative and quantitative study by light and scanning electron microscopy. Ribeirão Preto, 2013. 233 p. Thesis (PhD) -Ribeirão Preto School of Dentistry, University of São Paulo. Abstract During and after the process of alveolar repair post-extraction, bone remodeling occurs with certain
... curs with certain dimensional reductions of this tissue that can compromise the therapy in implantology. In order to preserve/reconstruct such tissue, various methods are proposed using different types of biomaterials and techniques which demonstrate the capacity to form bone. The autogenous bone is still regarded as the gold standard bone graft, due to their osteogenic, osteoinductive and osteoconductive potential, but morbidity is known about it. Therefore some bioceramics have been used, as they are synthetic, biocompatible and with good properties of bone fill, but with low osteogenic potential. The bone tissue engineering consists of mesenchymal stem cells differentiated into osteoblasts is a strategy for providing additional cell in the bone defect reconstruction. The aim of this study was to qualify and quantify bone healing after grafting of an association of autogenous bone and osteoblastic cells carried by a bioceramic in bone defects produced by tooth extraction. The animals were divided according to the implanted material in dental socket after extraction: Control (c), autogenous bone (ab), osteoblastic cells (oc), bioceramic (bc), autogenous bone + osteoblastic cells (ab+oc), autogenous bone + bioceramic (ab+bc), bioceramic + osteoblastic cells (bc+oc), and bioceramic + autogenous bone + osteoblastic cells (bc+oc+ab). The animals were sacrificed at 7, 21 and 42 days post-surgery and tissue samples were processed for light microscopy and scanning electron microscopy. Through an image analysis system the quality of implanted biomaterials and the volume of bone, bioceramic, conjunctive tissue and blood clot was evaluated inside the bone defect. Qualitative results revealed that the grafted bioceramic was biocompatible and intimately bonded with the bone. The use of osteoblastic cells, autogenous bone or bioceramic didn't trigger immunogenic reactions, foreign body or tumor formation. Histometrically, the osteoblast cells carried by bioceramic showed a bone filling 19.0% higher than when not carried. The bioceramic/osteoblastic cells + autogenous bone association promoted, at 7 days, a bone deposition 56.52% more effective around the biomaterial than the grafting of bioceramic alone (1%). It was concluded that the bioceramic in question may be a viable carrier to osteoblastic cells to be grafted on sites of bone reconstruction, and this hybrid compound receives a synergistic effect when associated to autogenous bone, thus being able to accelerate the bone formation especially in the early periods of alveolar repair.