Papers by Keyword: Rabbit Tibia

Abstract: The study aimed the evaluation of the effect of osseous repair in the synthetic hydroxyapatite cylinder (HA) implanted in rabbit’s tibia. Fifteen adult animals, weighing around 2.5 and 3.0 Kg, sourced by the Fluminense Federal University Animal Lab were anesthetized with spinal anesthesia, and two perforations were created in right tibia and filled with cylinders (2 x 6 mm) of HA. The animals were killed after 28 days for evaluating the HA cylinder through attenuated total reflection infrared microscopy (ATR-FTIR). The two fragments of tibia with the cylinder were collected and fixed in alcohol 70° prior to dehydration in successive alcohol solutions and then impregnated and embedded in methyl-methacrylate. Not stained neither pasted to lamina, sections of 200 µm thickness were analyzed in a Shimadzu IRPrestige-21 Automatic Infrared Microscope (AIM-8800) with ATR Objective Mirror (ATR-8800M). Prior to implantation, HA cylinder was characterized by X-Ray diffraction (XRD), Attenuated Total Reflection- Infra Red microscopy (ATR-FTIR) and X-Ray Fluorescence (XRF). After the implantation, the spectrum of the ATR-FTIR at the interface to neoformed bone was acquired. The hydroxyapatite synthesized was crystalline and stoichiometric with Ca/P ratio of 1.66, becoming carbonated after 28 days of implantation. We conclude that attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) is a useful tool for biomaterial evaluation and able to detect the modification of the chemical HA cylinder pattern occurred probably by ions migration in the biological environment.

Abstract: The study was carried out aiming the evaluation of the effect of hydroxyapatite (HA) and zinc-substituted hydroxyapatite (ZnHA) on osseous repair of rabbit’s tibia. For the study, 15 adult animals, weighing around 2.5 and 3.0 Kg, sourced by the Fluminense Federal University Animal Lab were acquired. Two perforations were created in each tibia and filled with cylinders (2x6 mm) of HA (group 1, right) or ZnHA (group 2, left). The animals were killed after 7, 14, and 28 days for evaluating the histological aspects of the interface site and bone repair. No sign of inflammatory reaction surrounding the cylinders area were observed, neither giant cells. Osteogenesis was evidently accelerated in all healing periods for the ZnHA group in regards to the HA group. Randomly dispersed areas of neoformed bone among wide areas of fibrous connective tissue was observed in the HA group. We conclude that both biomaterials are biocompatible, but zinc-containg HA enhanced and accelerated the osteogenesis in relation to HA.

Abstract: To clarify new bone tissues, radiography with a newly developed tunable wavelength and highly parallel Parametric X-ray, PXR, was applied. Methods: PXR was generated by a LINAC at LEBRA, Nihon University (Hayakawa et al., 2005). X-ray wavelength was tuned from 7 KeV, 0.177 nm, to 16 KeV, 0.0775 nm. Coated or grit-blasted Ti-alloy implants modified with coating or blasting were implanted in surgically created defects in rabbit tibia. Undecalcified polished thin sections were prepared from the implant/bone areas 1 and 4 weeks after implantation. Results: PXR radiography showed a distinct difference between the newly formed bone and the compact bone. Color-mapping of the images showed an increase in the total amount of bone formation with time. Conclusion: Application of LEBRA-PXR, a high-powered, highly monochromatized and highly parallel oriented X-ray allowed easy and accurate radiographic analysis of new bone formation around the implant.