Papers by Keyword: Xenograft

Abstract: Bovine bone xenograft was selected bioactive material currently widespread acceptable for using as human bone void filler. In this paper we described a new porous bioceramic block fabricated from bovine bone powders mixed with calcium phosphate glass. The characterized methods were atomic absorption spectrometer, x-ray diffraction, scanning electron microscope, energy dispersion x-ray spectroscopy, diffusion test, bending test, compressive test and Archimedes’ principle. The final products showed interconnecting pores size range 100 to 500 mm, apparent porosity about 52% and mole ratio of Ca:P as 1.65. The toxic elements such as arsenic, cadmium, mercury, and lead were lower standard limits of ASTM I (American Society for Testing and Materials International). The samples had a compressive strength more than 400 kg/cm². So, this object can be useful as an alternative choice for human bone substitute in the vertical compression load bearing area.

Abstract: This clinical study evaluated the tissue repair process using different bone grafts. Nine dental patients with indication for posterior implantodontic treatment were submitted to maxillary sinus lifting procedures associated to grafting. After 6 months, bone biopsies (6 sites with allogenous bone grafting and 13 sites with bovine xenogenous bone grafting/Osseus^TM) were removed and processed for histopathological and histomorphometric analyses (ANOVA and Tukey's test). Both groups had tissue biocompatibility without significant inflammatory response, only punctual presence of multinucleated giant cells in xenograft group. Osteoconductive potential was evidenced by new bone tissue surrounding and in direct contact with the granules of both grafts. Volume density of connective tissue was similar between groups, although there were significant differences in allograft group in comparison to xenograft as the presence of new bone formation (48.50%±13.93 versus 29.83±9.56, respectively, p<0.05) and remnant biomaterial (1.57±2.39 versus 22.23±12.41, respectively, p<0.001), suggesting a greater osteoconductivity and faster bioresorption in the allograft group. These results demonstrate that allogenous bone and Osseus^TM can be satisfactorily used as grafts in minor oral surgeries for bone augmentation in humans.

Abstract: Dissolving behavior of hydroxyapatite ceramics prepared from bovine teeth (BTHA) was investigated. The bovine teeth were soaked in 0.1 M of NaOH at 80°C for 1 h. After soaking, the teeth were calcined at 800°C for 1 h, and then they were attritor-milled for 24 h. BTHA powder consisted of mainly HA and small amount of MgO. The powders obtained were cold isostatically pressed and sintered at 1200°C with a dwell time of 1 h. Sintered density of BTHA was about 70%. After polishing the surface of sintered specimen, BTHA was immersed in buffered water at 37°C for 3 and 7 days. After immersion period, there is no evidence of dissolution for BTHA at the end of the immersion time. In addition, there is no change of peak intensity in XRD after immersion time. It was found that hydroxyapatite from bovine teeth was more stable than commercial HA in liquid environment.

Abstract: The aim of this study was verify the biological efficacy of the use of a xenograft for bone loss therapy. Blood clot, particulate autogenous bone or anorganic bovine xenograft filled critical size defects (CSD) in rat calvaria (8mm diameter). After 0, 7, 30 and 90 days the animals were killed and macroscopic, radiographic and histopathological analysis were conducted. Although no treatment promoted the total closure of bone defect, autogenous bone group had better bone repair after 90 days, followed by xenograft group that exhibited direct bone neoformation onto, and around, the particles confirming its osteoconductivity. In conclusion, the xenograft tested in vivo showed biocompatibility, biodegradability and osteoconductive properties in rat calvaria CSD.

Abstract: Calcium phosphate bioceramics and bovine bone xenograft with or without sintering are more or less used in orthopaedics or in maxillofacial surgery. In this study we compare in a rat femoral epiphysis model after 3 weeks of implantation the bone in growth at the expense of granules of same size of micro macro porous biphasic calcium phosphate MBCP, sintered bovine bone and unsintered BioOss.

Abstract: Effect of heat-treatment temperature on the osteoconductivity of the apatite derived from bovine trabecular bone was investigated. Three different heat-treatment temperatures (600, 800 and 1000 oC) were adopted in the experiment and their effects on the physical properties of apatite granules, which could affect on the osteoconductivity, were evaluated. The content of carbonate ions in the apatite structure was assessed by FT-IR and its crystallinity was evaluated by X-ray diffractometry. The microstructure was assessed by field emission electron microscopy. Apatite granules heat-treated at 600 oC and 1000 oC were implanted into the calvaria of New Zealand White rabbit for 4 weeks, respectively, and the undecalcified ground histologic specimens stained with multiple staining method was observed. As increasing the heat-treatment temperature, the crystal size and crystallinity of the apatite increased while the content of carbonate ions decreased. The apatite granules heat-treated at 600 oC showed much better osteoconductivity comparing to that heat-treated at 1000 oC. The results were explained in terms of the physical properties of apatite which could affect to the osteoconductivity.