Avaliação do potencial osteogênico de matrizes tridimensionais colagênicas aniônicas, reticuladas ou não, em glutaraldeído, na regeneração de defeitos críticos, em calvária de rato

The aim of this study was to make a histomorphometric evaluation by common light microscopy, of the osteogenic potential of anionic collagen matrices, either reticulated in glutaraldehyde or not, implanted in critical bone defects in rat calvarias. In this study 86 rats were used, randomly divided into four groups: Gl - anionic collagenous matrix with 24h of hydrolysis and 5 min of reticulation in GA 0.05% (MCAHGA); Gll - anionic collagenous matrix with 24h of hydrolysis (MCA); Gill - neutral collagenous matrix, positive control (MCN) and GIV - empty bone defect, without biomaterial implantation, filled with blood coagulum, negative control. The animals were evaluated at the biological points of 15, 45, 90 and 120 days. The results evidenced that the biomateriais implanted in groups I and II were biocompatible, although they had set of chronic, discrete and regressive granulomatous inflammation. These matrices presented a speed of biodegradation compatible with bone neoformation, which was shown to be associated with angiogenesis inside the matrices at all the biological points. In G III, fragmentation and biodegradation were shown to be accentuated by the absence of chemical treatment of the collagen. The neomineralization evidenced in Groups I and II presented statistically significant increase throughout the times. The percentage of mineralization of Gll (87%) differed statistically from that found in Gl (66%). When these percentages were compared with the mineralization observed in GIV, very significant differences were noted. In the latter, as in Gill, bone neoformation was limited to the edges of the defect with fibrosis in the sectional area of the defect. It was concluded that the anionic collagen matrices presented more evident osteogenic potential in the matrices without reticulation in glutaraldehyde. These matrices presented a great potential for clinical application in bone regenerative therapies.