Avaliação da hidroxiapatita HAP-91® e vidro bioativo no reparo de defeitos ósseos críticos em calvárias de ratos

Abstract

Synthetic materials, such as bioceramics based on phosphate and calcium, have a composition similar to bone tissue, and are increasingly used in the repair of bone defects in the craniomaxillofacial region. Understanding the behavior of these materials is extremely important for their correct indication and clinical success. Thus the objective of this study was to evaluate HAP-91® Hydroxyapatite and Bioactive Glass as bone substitutes in critical-sized defects in rat calvaria. For this, sixty rats were divided into three groups according to the following local treatments: Control Group (C) - accomplishment of a bone defect in calvaria of the animals that was filled only with blood clot; Hydroxyapatite Group (HA) - defect filled with Hydroxyapatite (HAP-91®) and Bioactive Glass Group (VB) - defect filled with Bioactive Glass. The animals were euthanized at 30 and 60 postoperative days for histomorphometric and immunohistochemical analysis. In the intergroup analysis, the results showed that Group C presented a greater area of bone neoformation (ANO) compared to Group HA and VB. In addition, the HA Group presented a higher ANO compared to Group VB at 30 and 60 days post- (P <0.05). In our immunohistochemical results, Group C showed no expression of Osteocalcin (OC) at 30 days, while HA and BV Groups presented high and moderate expressions of OC respectively. The HA group presented a higher number of TRAP positive cells compared to Group C and Group VB at 30 and 60 postoperative days (p <0.05). Within the limits of this study we can conclude that both Hydroxyapatite (HAP-91®) and Bioactive Glass guided the formation of a new bone tissue, serving as a scaffold for the spatial maintenance of critical-sized bone defects in the calvaria of rats