Papers by Keyword: Bone Substitute

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: Modern traumatology is characterised by increasingly severe injuries, with significant soft tissue and bone loss; therefore, restoration of functional anatomy regards bone filling with proper bone integration, and otherwise surgical reconstruction is useless. Therefore, orthopaedic surgeons must have not only surgical skills, but thorough knowledge about the properties and indications of bone substitutes, which can improve surgical results in treating especially comminuted fractures. Integrating the clinical experience from a Level 1 Trauma Centre with didactic principles, and using e-learning as an educational tool, this paper refers to establishing an algorithm of clinical indications of bone substitutes in orthopaedic surgery and to introducing it into the educational process of orthopaedic trainees, as a component of vocational training.

Abstract: Carbonate Apatite (CO₃Ap) cement is considered as an ideal bone substitute due to its biocompatibility and osteoconductivity. Also, CO₃Ap cement has the chemical composition that closes to natural bone. During cement preparation, precursors play an important role that affects the properties of CO₃Ap cement. Cement hardness is one of the important properties that need to be evaluated before the obtained cement can be applied as a bone substitute. Therefore, the purpose of this study is to determine the effect of precursor ratio of CaCO₃ and CaHPO₄ on the hardness level of CO₃Ap cement. In the present study, the CO₃Ap cement was prepared from CaCO₃ and CaHPO₄. Both Commercial and synthesized CaCO₃ were used. The CO₃Ap cement obtained from commercial CaCO₃ was used as a control group. Synthesized CaCO₃ was obtained from Indonesian natural limestone. Three different CaCO₃:CaHPO₄ ratios, 40:60, 30:70 and 20:80 were mixed with 1 mol/L Na₂HPO₄. Samples were kept at 37^°C with 100% relative humidity for 24 hours then tested using micro Vickers hardness testing machine. The micro Vickers hardness of the control group with CaCO₃:CaHPO₄ ratio of 40:60, 30:70 and 20:80 were 5.09 VHN, 6.34 VHN, and 6.73 VHN, respectively. Meanwhile, the micro Vickers hardness of the CO₃Ap cement obtained from synthesized CaCO₃ were 6.22 VHN, 7.50 VHN, and 10.37 VHN for the CaCO₃:CaHPO₄ ratio of 40:60, 30:70 and 20:80, respectively. The micro Vickers hardness level of CO₃Ap cement precursor ratio from the lowest to the highest was 40:60 < 30:70 < 20:80. In conclusion, the precursor ratio significantly affects the hardness level of the CO₃Ap cement. The hardness level of CO₃Ap cement obtained from synthesized CaCO₃ was higher compared with that obtained from commercial CaCO₃.

Abstract: The bone remodeling process plays an essential part of the calcium homeostatic system and provides a crucial mechanism for adaptation to physical stress, the repair of damaged bone and the removal of old bone. We reported previously that sustainable release of simvastatin (SIM) from poly (lactic-co-glycolic acid) (PLGA) formulations could induce bone formation. The aim of this study was to develop a simvastatin-releasing PLGA/β-TCP composite microspheres (β-SPMs) sintered scaffolds (β-SPMSS) as a synthetic bone substitute, and investigate the influence of the dissolution medium on the drug release capabilities of these device based on a physicochemical model for bone remodeling. X-ray diffraction analysis (XRD) results showed β-TCP and SIM could be encapsulated into the PLGA microspheres. The β-SPMs and the β-SPMSS were able to produce sustained release of SIM for 1 month in simulated body fluid (SBF), whereas these composites released SIM for 10 days in acetate buffer (AB). The release rate of SIM from β-SPMSS in AB was faster than in SBF, indicating that the β-SPMSS could control drug release with bone cells activity response, and could be used as a scaffold in bone remodeling area. These results suggested that the β-SPMSS could release SIM sustainably, with bone cells activity response, and could be used as a scaffold in bone remodeling area.

Abstract: The aim of present study was to fabricate porous a-tricalcium phosphate (a-TCP) with adequate mechanical strength and pore interconnectivity. First step, a-TCP spheres were exposed to acidic calcium phosphate solution to allow growth and interlocking of dicalcium phosphate dihydrate (DCPD) crystals precipitated on the surface of the a-TCP spheres. Then, the DCPD-coated a-TCP spheres were sintered at 1,500°C for 6h, which resulted in the fusion of spheres to form the interconnected porous block. XRD analysis showed single phase a-TCP was obtained. Mechanical strength of porous a-TCP was 6.9 ± 1.6 MPa and porosity was 53 ± 5%. The obtained porous a-TCP could be employed as potential bone substitute or precursor for other bioceramics like carbonate apatite and hydroxyapatite.

Abstract: NanoBone^® Block is the alternative to autogenous bone blocks and offers doctors a rapid, simple operating procedure in combination with a low risk of complications. Aim of this work was to develop a bone grafting block with elastic properties for dental and orthopedic surgery which is ready to use. An easy handling has to be connected with quick regeneration. Therefore, NB granules have been combined with an elastic hydrogel carrier based on Polyvinylpyrrolidone (PVP) and silica sol. Mechanical properties were optimized for an enhanced handling by cross linking and simultaneous sterilization of the PVP with gamma radiation. Cross linked PVP has the capability of swelling in water without being solved. To approve biocompatibility of adjusted material an in vivo study was analyzed using a standardized bone defect model in rat tibiae. Defect was filled with elastic bone grafting material. After 21 and 63 days rats were sacrificed and tibias analyzed. Histomorphological analysis showed an increased bone formation but even a decelerated resorption of elastic biomaterial. Quantitative compositional analysis showed a decrease in silicon content of granules as a process of matrix change.

Abstract: The aim of the present study was the in vitro investigation of a synthetic bone graft substitute loaded with individual antibiotics for the treatment of osteomyelitis and infectious bone disease. The elution of gentamicin, an aminoglycoside antibiotic, from the NanoBone^® products NanoBone^® S granules (NBG) and lyophilized NanoBone^® (NBP) putty was tested over a period of one week. An indirect photometrically-based detection system was used to measure the released antibiotic concentration. Both materials showed very different release behaviour. After one day lyophilized NanoBone^® putty delivered 100% of the gentamicin value, whereas NanoBone^® S granules released one-fifth of the used gentamicin level.

Abstract: In an In vivo study the full synthetic bone substitute NanoBone^® S (NBS) was analyzed using a standardized bone defect (6 x 12 x 24mm) model in the ovine tibial metaphysis. The defect on the left side was filled with NBS granules and on the right side, autologous bone, harvested from the hip of the same animal, was inserted. After six, 12 and 26 weeks sheep were sacrificed and the tibiae analyzed. Quantitative histomorphological analysis after six weeks showed a resorption of biomaterial from over 60 to 24 percent. In contrast the bone formation after 6, and 12 weeks revealed an osteoneogenesis of 19%, and 34%, respectively. Hematoxylin and eosin sections demonstrated multinucleated giant cells on the surface of the biomaterial and resorption lacunae, indicating osteoclastic resorptive activity.

Abstract: The present research paper centers on physicochemical characterization of six nanostructured alloplastic bone substitutes developed at Santa Catarina State University (UDESC Brazil). In addition to identifying the main phases, the focus was to measure the morphological and microstructural features, which are believed to be crucial for controlling and guiding biological and molecular events. The studied samples exhibited rounded granules measuring 200μm 10(PO₄)₆(OH)₂] was found as main phase for HAp, BCP and HAp/Al₂O₃ biomaterials. For HAp/TiO2n, HAp/SiO₂n and β-TCP, the major phase was beta tricalcium phosphate [Ca₃(PO₄)₂-β]. The results demonstrate that the presence of a second phase of nanometer order, at a hydroxyapatite bioceramic matrix, may modify the surface diffusion of the grains and the phase transformation kinetics of hydroxyapatite and beta tricalcium phosphate at temperatures up to 1100°C.

Abstract: Modern traumatology is characterized by high energy trauma, simultaneously affecting parts of the body especially in young patients. One of the most severe aspects resulting of high energy trauma is that of multiple skeletal injuries, with bone loss, which require complex treatment; this refers both to methods of filling the bone defects and to interdisciplinary approach whenever soft tissues are injured, as well. This case demonstrate the impact of modern approach in high energy trauma, with multiple aspects: bone substitutes as effective technique of bone filling and prevention of septic complications, as well as team work for concomitant treatment of associated injuries. The outcome of the patient, compared to the initial status, demonstrate the benefit of bone substitutes for a rapid recovery of trauma patients, with major impact on social and professional recovery.