Standardized Study of Carbonate Apatite as Bone Substitute in Rabbit’s Tibia

Abstract

The objective of this study was to investigate the bone repair of carbonate apatite (cHA) in comparison to hydroxyapatite (HA, control group) on osseous repair of rabbit’s tibia. Spheres (400-500 µm) of both materials were synthesized under 37°C (cHA) and 90°C (HA) and were not sinterized. Ethics Commission on Teaching and Research in Animals approved this project (CEPA/NAL 208/10). Six White New Zealand rabbits were submitted to general anesthesia and one perforation (2mm) was made in each tibia for implantation of cHA (left tibia) and HA spheres (right tibia). After 4 weeks all animals were killed and one fragment of each tibia with the biomaterial was collected with a total of 6 bone blocks for each group. Five bone blocks of each group were demineralized and 5-µm thick semi-serial sections were stain with Hematoxillin and Eosin and Trichromic of Masson for histological analysis and two fragments were collected and embedded in a methacrylate-based resin and cut into slices with ~30 µm and were analyzed by light microscopy (bright field and polarized microscopy). Both groups didn’t show the spheres after 4 weeks, new-formed bone was observed from the periphery toward to the center of the surgical defect, which was even filled with connective tissue. Both materials are biocompatible, promote osteoconduction and showed to be resorbable.