Avaliação radiográfica e histológica da reparação óssea em tíbia de coelhos utilizando implantes de silicato de cálcio.

Abstract

This dissertation is composed of two chapters. The first objective was to carry out a systematic review of clinical studies with the use of bioceramics in the repair of bone tissue in different animal species. For the accomplishment of this review an extensive online search of articles published and indexed in the electronic databases PubMed, Scielo and LILACS was employed. We sought to gather all the available studies, published a maximum of 10 years ago, which used bioceramic implants for bone repair. Inclusion and exclusion criteria were adopted. Thirty-five studies composed the present study. A considerable number of studies were carried out that met the inclusion criteria, evidencing the interest of several researchers in developing formulations of bioceramics that promote bone repair and have characteristics of biocompatibility and applicability, which are determinant properties for the recommendation of a biomaterial. Bioceramics are widely studied, due to their exceptional mechanical and biochemical properties. The use of different associations of bioceramics to create implants with high applicability and varied functions seems to be an increasing trend. In the second chapter, the objective of this study was to evaluate the use of a calcium silicatebased implant in the repair of rabbit tibiae. Twelve rabbits of both genders, of the New Zealand strain, weighing an average of 3 kg were used. The animals were randomly divided into two groups. The animals that composed group 1 underwent euthanasia at 30 days of study. The animals in group 2 were euthanized after 60 days of study. Orifices were made at both the proximal and distal metaphyses of the tibiae of each animal, these holes were filled with a calcium silicate-based implant in the straight limb and received no implants in the left tibia. The animals were submitted to clinical-radiographic evaluations and the samples were submitted to light microscopy and scanning electron microscopy. The calcium silicate implant provided bone growth characterized by the progressive increase of the radiopacity observed during radiographic evaluations. The histological findings showed a gradual degradation of the implants and new bone formation. It was concluded that the calcium silicate graft stimulated the beginning of the process of bone repair in rabbits.