Papers by Keyword: Biphasic Calcium Phosphate (BCP)

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Authors: Pierre Layrolle, Serge Baroth, Eric Goyenvalle, Eric Aguado, Françoise Moreau, G. Daculsi
Abstract: An hydrated putty was prepared by mixing submicron particles, rounded particles and granules of Biphasic Calcium Phosphate (BCP) ceramics composed of HA and β-TCP phases. The material filled entirely critical sized defects in the femoral epiphysis of NZW rabbits. After 3, 6 and 12 weeks, histology revealed that submicron particles were rapidly degraded by multinucleated TRAP-positive cells. This osteoclastic resorption stimulated bone ingrowth while the large BCP particles served as scaffold supporting bone healing by osteoconduction.
Authors: S.I. Yoon, Yong Keun Lee, Kyoung Nam Kim, S.O. Kim, H.K. Son, J.Y. Kwak, J.Y. Kim, H.J. Choi
Abstract: Previous studies have shown that hydroxyapatite increases the bonding strength of dental luting cement with human teeth by forming bone-like apatite when it is added to cement. However, due to the low solubility of the hydroxyapatite, its ability to form bone-like apatite decreases in protein-free acellular simulated body fluid with ion concentrations nearly equal to those of the human blood plasma. The purpose of this experiment was to increase the formation of bone-like apatite by mixing hydroxyapatite with β-TCP of high solubility. RelyXTM glass ionomer cement(3M/ESPE, USA) was used as dental luting cement. Film thickness, setting time, and compressive strength was measured for each group of 15% hydroxyapatite, 15% β-TCP, and 15% mixed hydroxyapatite and β-TCP (85:15). Every specimen of each group was immersed in the simulated body fluid for four week before measuring bonding strength, and then their sectional surface was observed under SEM. The most noteworthy result was that the group containing β-TCP produced more amount of bone-like apatite compared with the group composed of only hydroxyapatite.
Authors: Claire Jarry, Matthew Shive, Abdellatif Chenite
Abstract: The primary purpose of this study was to characterize the main features of a BCP-loaded chitosan-GP composite. The two-syringe design improves the storage conditions, facilitates the sterilization procedure and provides an easy-to-use injectable biomaterial, ensuring reproducible properties with minimal manipulation. Rheological measurements confirm that the chitosan- GP/BCP composite retains the thermosensitive properties already described for chitosan-GP hydrogels. At 37°C, the system gels within 10 minutes and reaches sufficient consistency after 30 minutes to prevent the mineral granules from migration into the surrounding tissues in vivo. The compressive force needed for the injection of chitosan-GP/BCP before gelation is approximately 6.6 N, only about 6 times that required for water and much lower than the average force that the majority of adults can exert. Morphology was investigated by environmental scanning electron microscopy (ESEM), which revealed 3-D dispersion of BCP granules embedded in chitosan-GP hydrogel. This open, porous structure affords complete access for body fluids and cells to each mineral granule immediately following implantation. The design using disposable syringes equipped with 16G hypodermic needles described here allows easy in vivo delivery of a fully injectable biomaterial containing porous scaffold that naturally enhances the osteogenic activity recognized for both chitosan and BCP.
Authors: Y. Zhang, Yoshiyuki Yokogawa, Tetsuya Kameyama
Abstract: Biphasic calcium phosphate (BCP) ceramics, a mixture of hydroxyapatite (HAp) and beta-tricalcium phosphate (β-TCP), of varying HAp/β-TCP ratios were prepared from fine powders. Porous BCP ceramic materials with HAp/β-TCP weight rations of 20/80, 40/60, and 80/20 were prepared. In this study, the bioactivity is reduced at a larger HAp content rate, which is likely related to the high driving pore for the formation of a new phase, and the reaction rate was proportional to the β-TCP. The porous BCP ceramics having a bigger porosity rate can easily under up dissolution. The powder having a larger β-TCP content rate can easily generate a new phase. The dissolution results confirmed that the biodegradation of calcium phosphate ceramics could be controlled by simply adjusting the amount of HAp or β-TCP in the ceramics and porosity rate.
Authors: Shu Jie Lin, Racquel Z. LeGeros, Ramin Rohanizadeh, Dindo Q. Mijares, John P. LeGeros
Authors: Racquel Z. LeGeros, John P. LeGeros
Authors: A.B. Diggs, J.W. Halloran, S.J. Hollister
Abstract: This paper describes the investigation into the use of cathodoluminescence for distinguishing HA and β-TCP phases within the biphasic calcium phosphate ceramic microstructure. Polished samples were scanned using SEM-CL at an accelerating voltage in the range of 10-15 keV with a beam current of 5-10 nA. The grayscale images produced reveal distinctive patterns for each composition. EDS and EPMA suggest chemical differences among the contrasting regions. Image analysis of voxel values indicate that areas of bright contrast correspond to β-TCP grains with phase amounts confirmed by XRD.
Authors: Wafa I. Abdel-Fattah, Fikry M. Reicha, Tarek A. Elkhooly
Abstract: Two biphasic BCP ceramic samples were synthesized by chemical precipitation and microwave curing of calcium deficient hydroxyapatite CDHA under the same pH value and temperature but varied in their initial Ca/P molar ratio. Precipitates were characterization after thermogravimetric analysis, fourier transform infrared spectroscopy, X-ray diffraction, atomic absorption spectroscopy and TEM. Hydroxyapatite (HA) contents were measured for the two biphasic calcium phosphate (BCP) ceramics by sintering the calcium-deficient apatites (CDHA). The results reveal two condensation mechanisms of HPO42- affecting the Ca/P molar ratio after calcination. The X-ray diffraction patterns of BCP powders show the in situ formation of -TCP in the BCP powder. The amount of -TCP phase increases as the initial Ca/P molar ratio decreases due to more calcium deficiency in CDHA structure. The influence of HPO42- incorporation on increasing -TCP phase content after calcination is evaluated. TEM micrographs proved the effect of microwave curing during the preparation process on reducing of particle size to nanoscale range and the destruction of CDHA to finer HA and -TCP particles upon calcination.
Authors: Cristina C. Teixeira, Racquel Z. LeGeros, Claudia Karkia, Yelena Nemelivsky
Authors: G. Daculsi, H. Pascal-Moussellard
Abstract: The objective of the study was to compare clinical efficiency of the fusion after reconstruction with an anatomically shaped PEEK cage associated with a iliac crest autograft or MBCP in the treatment of cervical disc disease in randomized clinical trial. A multicente randomized, comparative and prospective study on 58 patients, with a 12 months follow up are reported. They underwent anterior cervical decompression and fusion being randomized for autologous graft or MBCP. Patients presenting purely degenerative disc disease were implanted with a PEEK cage filled with iliac crest autograft or MBCP. Pain and functionality as well as patients satisfaction were assessed through VAS, Neck Disability Index (NDI) and Patient Satisfaction index were recorded until 24 month follow-up. Radiological evaluation included plain and dynamic short X-rays at each stage of the follow up. The patients satisfaction rates was of 82% in the autograft group versus 96% in the MBCP group. Pain at the donor site was significantly more important in the autograft group at 3 weeks, 3 months and 1 year follow-up. No implant failures were recorded. Previously goat preclinical study was performed. Micro CT, light microscopy and shistomorphometry were related to the high performance of the MBCP insert for filling cage fusion, completing the clinical assessment of our clinical study. The use of MBCP insert is safe and avoids potential graft site morbidity and pain in comparison with an autologous graft procedure.
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