Biocerâmica de hidroxiapatita e trifosfatos de cálcio de absorções rápida e lenta no reparo de defeitos ósseos em ratas Wistar com ou sem osteopenia induzida

Abstract

The aim of this study was to evaluate the effect of the fast and slow absorptions of / HA bone substitute on bone repair of rats with or without induced osteopenia. The project was developed in two stages: induction of osteopenia (Chapter I) and implantation of the biomaterial (Chapter II). In the osteopenia induction phase, 18 Wistar (Rattus norvegicus) albino rats with a mean body mass of 300 grams and 6 months of age were used. Osteopenia was induced by ovariosalpingohisterectomy associated with a hypocalcemic diet and was evaluated by radiographic bone density and measurement of biochemical markers alkaline phosphatase and osteocalcin. In all rats there was an increase in serum levels of FA and OC and reduction of bone radiographic density, characterizing the osteopenic condition. In the second phase of the project, 36 Wistar rats (Rattus norvegicus) with average body mass of 300 grams and six months of age were used. The rats were divided into two groups: animals submitted to ovariohysterectomy and hypocalcemic diet (OSH Group) and uncastrated animals with commercial diet (Control Group). After confirming the osteopenic induction by means of bone radiographic density in the OSH group, a bone defect was created in the proximal third of the right and left tibias in all the animals. These were subdivided into two groups: treated with defect filling with fast and slow absorption / HA / TCP and negative control group in which the defect remained empty. Radiographic evaluations were performed on days 0, 15 and 30 after implantation and histological evaluations at 15 and 30 days. Formation of vascular networks, osteoid tissue and bone matrix were observed in all groups treated with fast and slow HA / TCP, favoring the repair process; in the negative control groups, fine and discontinuous cortical formation was observed from the preexisting bone. The rapid and slow absorption of / HA is an ideal biomaterial in the treatment of bone failure promoting regeneration. Fast-absorbing -HA / TCP proved to be a promising material for repairing bone defects with a more organized neoformation.