β-TCP Powder Research Articles

The effect of acidic treatment of carbon fiber on denture mechanical properties

The purpose of this research is to increase the mechanical properties (impact and flexural strength) of acrylic polymethyl methacrylate (PMMA) denture base resin by incorporated treated and coated woven carbon fiber (WCF). To increase the roughness of fibers, WCF treated with para-aminobenzoic acid (PABA), (C7H7NO2) at 3 different concentration treatments (0.10, 0.15, and 0.20 M). In order to make the samples appears with good aesthetic and bonding, WCF was coated with β-Tricalcium phosphate (β-TCP) powder with (0.08, 0.10, and 0.12) weight fraction (wi) in addition of using polyvinyl alcohol (PVA) at 0.01 wi, respectively. After 10 days of water storage at room temperature, the specimens have been tested via using the Charpy effect measuring system and three-point bending tests. The mechanism of interfacial interaction between β-TCP and woven carbon fibers was investigated by field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR). Based on the obtained results, when specimens contained treated and uncoated woven carbon fiber with a high concentration of (PABA), the impact and flexural strength were higher than pure sample but have a bad aesthetic. Further, (PMMA) reinforced with coated and treated woven carbon fiber as hybrid composites recorded very high raises in the mechanical properties when the concentration of (PABA) and (β-TCP) was increased, with a good aesthetic.

Synthesis and Characterization of Mesoporous β-Tricalcium Phosphate

Reconstruction of bone defect due to a disease or a trauma can use autograft, allograft, xenograft or synthetic bonegraft as the bone substitute material. However, in particular cases, it is required a material that has a specific resorption characteristic, beside owning excellent bioactive properties, such as β-tricalcium phosphate (β-TCP). In this study, we report the synthesis of β-TCP particles with mesopores structure by using chitosan and aloe vera as templates. A solution of (NH4)2HPO4 was added dropwise into solution of Ca(NO3)2·4H2O and the template at 85°C for 2 hours, and subsequently aged for 3 hours. Then, the formed precipitate was washed and centrifuged repeatedly prior to drying at 80°C for 24 hours. Finally, the dried precipitate was calcined at 900°C for 1 hour to obtain β-TCP powder. Phase identification and mesopores structure were analyzed using X-ray diffraction (XRD), while the existence of functional groups was identified by Fourier-transform infrared (FTIR) spectroscopy. Microstructure and particle size distribution were characterized by scanning electron microscopy (SEM) and particle size analyzer (PSA), respectively. XRD analysis shows that β-TCP is dominant with the presence of small amount of impurities. Furthermore, low angle peak in XRD analysis indicates the formation of mesopores structure. From the SEM and PSA analysis, the morphology of both TCP-K and TCP-KA particles showed more large agglomerates and more heterogeneous particle size distribution due to the addition of the biopolymers in the synthesis of β-TCP.

Biomechanical Evaluation of an Injectable Alginate / Dicalcium Phosphate Cement Composites for Bone Tissue Engineering

Biocompatible dicalcium phosphate (DCP) cements are widely used as bone repair materials. In this study, we aimed to investigate the impact of different amounts of sodium alginate (SA) on the microstructural, mechanical, and biological properties of DCP cements. Beta-tricalcium phosphate (β-TCP) was prepared using a microwave-assisted wet precipitation system. Lattice parameters of the obtained particles determined from X-ray diffraction (XRD), were in good match with a standard phase of β-TCP. Scanning electron microscopy (SEM) examination revealed that the particles were in globular shape. Furthermore, all functional groups of β-TCP were also detected using Fourier-transform infrared spectroscopy (FTIR) spectra. DCP cement (pure phase) was synthesized using monocalcium phosphate monohydrate (MCPM)/β-TCP powder mixture blended with 1.0 mL of water. SA/DCP cement composites were synthesized by dissolving different amounts of SA into water (1.0 mL) to obtain different final concentrations (0.5%, 1%, 2% and 3%). The prepared cements were characterized with XRD, SEM, FTIR and Thermogravimetric analysis (TGA). XRD results showed that pure DCP and SA/DCP cements were in a good match with Monetite phase. SEM results confirmed that addition of SA inhibited the growth of DCP particles. Setting time and injectability behaviour were significantly improved upon increasing the SA amount into DCP cements. In vitro biodegradation was evaluated using Simulated body fluid (SBF) over 21 days at 37 °C. The highest cumulative weight loss (%) in SBF was observed for 2.0% SA/DCP (about 26.52%) after 21 days of incubation. Amount of Ca2+ ions released in SBF increased with the addition of SA. DCP and SA/DCP cements showed the highest mechanical strength after 3 days of incubation in SBF and declined with prolonged immersion periods. In vitro cell culture experiments were conducted using Dental pulp stem cells (DPSCs). Viability and morphology of cells incubated in extract media of DCP and SA/DCP discs after 24 h incubation was studied with MTT assay and fluorescence microscopy imaging, respectively. All cements were cytocompatible and viability of cells incubated in extracts of cements was higher than observed in the control group. Based on the outcomes, SA/DCP bone cements have a promising future to be utilized as bone filler.

Fabrication, Characterization and In Vitro Cytotoxicity of Mesoporous β-Tricalcium Phosphate Using the Spray Drying Method

Mesoporous beta tricalcium phosphate (β-TCP) has recently attracted significant interest as an artificial bone tissue in orthopedics. However, a scalable process is required to meet future demands. Spray drying is one of the potential synthesis methods owing to its low cost and scalable production. In this study, various mesoporous β-TCP powders were calcined in the range of 800 to 1100 °C, with particle sizes ranging from ~0.3 to ~1.8 μm, specific surface areas from ~16 to ~64 m2/g, and average pore sizes of 3 nm. Except for the 800 °C calcined powder, the other β-TCP powders (calcination temperatures of 900, 1000, and 1100 °C) exhibited no cytotoxicity. These results indicate that spray-dried mesoporous β-TCP powders were obtained. Finally, the corresponding formation mechanisms are discussed.

Calcium Release from Different Toothpastes after the Incorporation of Tricalcium Phosphate and Amorphous Calcium Phosphate

This study aimed to investigate the free calcium released from different brands of toothpaste after incorporation with a beta-tricalcium phosphate (β-TCP)/amorphous calcium phosphate (ACP) mixed powder and with β-TCP powder alone. Four brands of toothpaste were used for the experiment: Nano-Bio Activation Toothpaste, Colgate Total Advanced Whitening Toothpaste, BORONIA Herbal Whitening, and BioMin F. The investigated β-TCP and ACP powders were prepared by a two-step sintering method using raw coral material. Analytical results found that the mean calcium concentration of the β-TCP/ACP (2:1) powder in deionized water was 3.4% when the pH was between 5 and 9. Moreover, statistical results revealed that the toothpaste containing β-TCP powder had significantly higher calcium concentrations than the normal toothpaste. The toothpaste containing mixed β-TCP/ACP powder had a higher calcium concentration than the toothpaste containing only β-TCP powder. Twice as much free calcium could be released from β-TCP/ACP toothpaste than from β-TCP-only toothpaste. Thus, toothpaste containing β-TCP/ACP mixed powder offers greater benefits to facilitate the remineralization of enamel than toothpaste containing only β-TCP.

Chemically pure β-tricalcium phosphate powders: Evidence of two crystal structures

The question whether β‐tricalcium phosphate (β‐TCP) can form a solid solution with β-calcium pyrophosphate (β-CPP) and/or hydroxyapatite (HA) has still not been solved. For this reason, wet-chemically synthesized β-TCP powders with only 20 ppm Sr (among 43 tested elements) and with different HA and β-CPP contents, or in other words Ca/P molar ratios, were used. The graphical relationship between these various Ca/P molar ratios determined by X-ray diffraction and by inductively-coupled plasma mass spectrometry showed no discontinuity, indicating the absence of a solid solution between β‐TCP and β-CPP or HA. Analysis of the β‐TCP lattice parameters as a function of the Ca/P molar ratio revealed a discontinuity at a Ca/P molar ratio of 1.500 and a maximum microstrain. These results indicated that at least two β‐TCP structures co-existed, with variable mixing ratios depending on the Ca/P molar ratio, and with a distinct jump at a Ca/P molar ratio of 1.500.

Evaluation of direct light processing for the fabrication of bioactive ceramic scaffolds: Effect of pore/strut size on manufacturability and mechanical performance

Bioactive ceramic scaffolds for bone regeneration consisting of a three-dimensional mesh of interpenetrating struts with square section were fabricated via Digital Light Processing (DLP). The ability of the technique to manufacture 3D porous structures from β-tricalcium phosphate (β-TCP) powders with different dimensions of struts and pores was evaluated, identifying the possibilities and limitations of the manufacturing process. Small pore sizes were found to seriously complicate the elimination of excess slurry from the scaffold’s innermost pores. The effect of the strut/pore size on the mechanical performance of the scaffolds under compressive stresses was also evaluated, but no significant influence was found. Under compressive stresses, the structures resulted weaker when tested perpendicularly to the printing plane due to interlayer shear failure. Interlayer superficial grooves are proposed as potential failure-controlling defects, which could also explain the lack of a Weibull size effect on the mechanical strength of the fabricated DLP scaffolds.

Synthesis of Calcium Phosphate Powders in Nonaqueous Media for Stereolithography 3D Printing

Methods were presented to synthesize tricalcium phosphate Ca3(PO4)2 (TCP), calcium pyrophosphate Ca2P2O7 (CPP), and TCP/CPP composites in nonaqueous media in the temperature range 25–300°C. It was shown that solvo- and ionothermal synthesis methods can give phosphates of complex composition. The phase composition, micromorphology, and particle size distribution of the obtained powders and their evolution during synthesis were described. The synthesis at 110°C while slowly adding ammonium hydrophosphate to a solution of calcium ethylene glycolate in ethylene glycol gives a nanocrystalline β-TCP powder with an average size of aggregates of platy crystals of 150 nm and a distribution width of 50 nm. The morphological characteristics and sinterability of the powders synthesized in solutions in ethylene glycol make them suitable for producing macroporous ceramics by stereolithography 3D printing methods.

Synthesis and characterization of antibacterial drug loaded β-tricalcium phosphate powders for bone engineering applications.

Powders of β-tricalcium phosphate [β-TCP, β-Ca3(PO4)2] and composite powders of β-TCP and polyvinyl alcohol (PVA) were synthesized by using wet precipitation methods. First, the conditions for the preparation of single phase β-TCP have been delineated. In the co-precipitation procedure, calcium nitrate and diammonium hydrogen phosphate were used as calcium and phosphorous precursors, respectively. The pH of the system was varied in the range 7-11 by adding designed amounts of ammonia solution. The filtered cakes were desiccated at 80 °C and subsequently calcined at different temperatures in the range between 700-1100 °C. Later on, rifampicin form II was used to produce drug-loaded β-TCP and PVA/β-TCP powders. All the synthesized materials have been characterized from morphological (by scanning electron microscopy) and structural-chemical (by X-ray diffraction and Fourier transform infrared spectroscopy) point of view. The drug loading capacity of the selected pure β-TCP powder has been assessed. The biological performance (cytocompatibility in fibroblast cell culture and antibacterial efficacy against Escherichia coli and Staphylococcus aureus) has been tested with promising results. Application perspectives of the designed drug-bioceramic-polymer blends are advanced and discussed.

Mesoporous Silica-Coated β-TCP Granules Prepared Using Alginate and <i>In vitro</i> Evaluation

β-Tricalcium phosphate (β-TCP) is widely used, along with bone-derived growth factor, due to its poor osteogenic ability. Mesoporous silica (MPS)-coated β-tricalcium phosphate (β-TCP) granules were prepared to improve protein loading capability, and in vitro evaluations of this material were carried out. β-TCP powder containing 2 wt% Al2O3 and 6 wt% SiO2 was prepared via mechanochemical synthesis. A sodium alginate solution containing β-TCP powder was transferred into a calcium chloride solution, and the obtained spherical beads were heated at 1100 to 1300°C to produce TCP granules. The X-ray diffraction (XRD) profile of the β-TCP granules containing 2 wt% Al2O3 and 6 wt% SiO2 was identical to that of the single β-TCP phase when heated to 1300°C. The compressive strengths of the TCP granules prepared using alginate were remarkably improved compared with those of TCP granules prepared using a pan-type granulator. A silica interlayer was formed on the β-TCP granules containing 2 wt% Al2O3 and 6 wt% SiO2 via magnetron sputtering prior to the coating of the MPS. MPS coatings on β-TCP granules containing 2 wt% Al2O3 and 6 wt% SiO2 was carried out by a dip-coating method after silica interlayer coatings, and the β-TCP granules containing 2 wt% Al2O3 and 6 wt% SiO2 were covered by the MPS particles. A silica interlayer may offer bonding between the β-TCP granules and MPS coating. The Alamar blue assay of the MPS-coated TCP granules exhibited excellent cell viability as well as a high protein-adsorption capacity.

Strategy to improve the mechanical properties of bioabsorbable materials based on chitosan for orthopedic fixation applications

Bioabsorbable polymeric fixation devices have been used as an alternative to metallic implants in orthopedics, preventing the stress shielding effect and avoiding a second surgery for implant removal. However, several problems are still associated with current bioabsorbable implants, including the limited mechanical stiffness and strength, and the adverse tissue reactions generated. To minimize or even eliminate the problems associated with these implants, strategies have been developed to synthesize new implant materials based on chitosan. To overcome the brittle behavior of most 3D chitosan-based structures, glycerol and sorbitol were blended to chitosan and the effect of these plasticizers in the produced specimens was analyzed by flexural tests, Berkovich tests, scanning electron microscopy (SEM) and micro-CT analyzes. The improvement of the mechanical properties was also tested by adding ceramics, namely hydroxyapatite powder and biphasic mixtures of hydroxyapatite (HA) and beta-tricalcium phosphate (β-TCP). In the plasticizers group, the best combination of the measured properties was obtained for chitosan with 10% glycerol (flexural strength of 53.8 MPa and indentation hardness of 19.4 kgf/mm2), while in the ceramics group the best mechanical behavior was obtained for chitosan with 10% HA+β-TCP powder (flexural strength of 67.5 MPa and indentation hardness 28.2 kgf/mm2). All the tested material compositions were dense and homogeneous, fundamental condition for a good implant performance. These are encouraging results, which support the continued development of chitosan-based materials for orthopedic fixation applications.

Metallic ion doped tri-calcium phosphate ceramics: Effect of dynamic loading on in vivo bone regeneration

The present study was carried out to evaluate the effect of dynamic loading on bone regeneration performance of different doped β-tri-calcium phosphate ceramics. We have developed porous beta tri-calcium phosphate (β-TCP), 5%zinc doped, 5% magnesium doped and 5% titanium doped β-TCP by aqueous solution combustion technique. All the synthesized β-TCP powders showed pore size of 21–146 μm (pure β-TCP), 16–142 μm (Zn-β-TCP), 28–156 μm (Mg- β-TCP) and 14–173 μm (Ti-β-TCP) while their apparent porosity 17.89%, 28.09%, 26.54% and 25.87% respectively. The pure and doped samples were implanted in femoral bone defect model (rabbit) to assess bone regeneration under dynamic loading. Bone regeneration was assessed after 1 and 2 month post-implantation on the basis of clinical radiological, histological, fluorochrome labelling, micro computed tomography (μ-CT) and scanning electron microscopy (SEM). Radiological and fluorochrome labelling study showed reduced size of 5%Ti-β-TCPimplant vis-à-vis more new bone formation as compared to other groups. Micro-CT of the implanted bone sample showed a significant amount of newly formed bony tissue surrounding the Ti-β-TCP implant as compared to other samples. Similar findings of less interfacial gap between the implant and bone were also observed in SEM study. However, all the doped materials are suitable as bone grafting material and have potential for application in bone tissue engineering.

Preparation of ex-situ Mixed Sintered Biphasic Calcium Phosphate Ceramics from Its Co-Precipitated Precursors and Their Characterization

ABSTRACTBiphasic calcium phosphate (BCP) ceramics was synthetically prepared by ex-situ method using hydroxyapatite (HAp) and beta tricalcium phosphate (β-TCP) powders. Both HAp and β-TCP were prepared by wet chemical co-precipitation and calcination method and were then mixed at two different weight ratios of 60:40 and 70:30. The mixed BCPs were then pressed and sintered at 1200o and 1250oC. Sintered pure HAp and β-TCP were also prepared for comparison purpose. Sintered products were then characterized for various properties. Higher density and strength values were found for the composition with higher HAp content and also the bioactivity on immersion in SBF (simulated body fluid) solution was found to be higher for HAp containing composition.

Synthesis of β-TCP by sol-gel method: variation of Ca/P molar ratio

Beta-TCP has been synthesized by sol-gel method in ethanol media with Ca/P molar ratio of 1.0–1.5. Phosphorous pentoxide solution was slowly added into calcium nitrate tetrahydrate solution with gentle stirring to produce white gel. The white gel was dried at 80°C for 20 hours and continued by calcination process at 800°C for 30 minutes. The results showed that pure β-TCP powders was obtained from Ca/P molar ratio of 1.3. For Ca/P of 1.0-1.2, beside β-TCP, a little amount of β-CPP were found and for Ca/P ratio of 1.4-1.5, hydroxyapatite was formed as secondary product. The crystallite size of β-TCP was in a range of 32.96-47.82 nm. Morphology changed due to Ca/P molar ratio in which the size of irregular shape β-TCP became bigger as Ca/P molar ratio increased from 1.0 to 1.3. The presence of hydroxyapatite in the product has not changed the morphology shape but reduced its grain size.

Processing and Properties of Biphasic Calcium Phosphates Bioceramics Derived from Biowaste Materials

Properties of biphasic calcium phosphates bioceramics derived from biowaste materials were investigated. The hydroxyapatite (HA) powder was synthesized from bovine bone via thermal treatment while β-tricalcium phosphate (β-TCP) powder was synthesized from mussel shells via solid state solution. Pure HA and β-TCP were successful obtained. The HA and β-TCP were mixed together and sintered at 1100 - 1350°C. The effects of the sintering temperature and the ratio of HA/ β-TCP on the properties of the studied samples were investigated. The sintering temperature at 1250°C presented the maximum value of density and hardness. X-ray analysis of BCP ceramics sintered at 1250°C presented multiple phases of calcium phosphate. Average grain sizes of the studied samples decreased as the ratio of HA increased.

Effect of Freezing Temperature on The Pore Formation of Beta Tricalcium Phosphate Scaffold

Beta-tricalcium phosphate (β-TCP) has been widely used for biomedical application due to its excellent mechanical strength, good tissue compatibility and outstanding chemical stability. There are several methods to fabricate porous scaffolds including solvent casting, phase separation, rapid prototyping and electrospinning methods. In the present study, β-TCP scaffolds were fabricated using freeze drying method. β-TCP slurry was frozen and freeze dried for 24 hours followed by sintering process to form β-TCP scaffolds. The porous β-TCP scaffold were fabricated at different percentages of β-TCP powder used (10 wt. %, 20 wt. % and 30 wt. %) and froze at different freezing temperature (-10°C, -20°C, -40°C and -80°C) in order to study the effect of these parameters on the pore formation of the scaffolds. Scanning electron microscopy (SEM) analysis for 30 wt. % β-TCP scaffold frozen at -10°C revealed acceptable pore size distribution with majority pore size within the range of 102.65 µm to 372.90 µm. Furthermore, this scaffold also possessed highest compressive strength of 0.31 MPa.

Microwave assisted solution combustion synthesis of β-tricalcium phosphate nano-powders

A new approach for synthesis of β-tricalcium phosphate (β-TCP) was investigated by microwave-assisted combustion method. Three different fuels, glycine, urea and citric acid were used and their effects on the β-TCP powders formation were investigated. The morphology of powders, chemical and phase constituent were determined by SEM, FTIR and XRD, respectively. The results indicated that β-TCP powders with high purity could be obtained when citric acid is used as fuel; and in case of glycine and urea small amounts of hydroxyapatite (HA), calcium pyrophosphate and calcium hydrogen phosphate were detected by XRD. The morphology of β-TCP particles was found to be depended on fuel type. More uniform particle size with higher β-TCP purity was obtained by citric acid as fuel.

Characterization of β-tricalcium phosphate powders synthesized by sol–gel and mechanosynthesis

β-Tricalcium phosphate (β-TCP) is one of the most investigated calcium phosphates to be used in bone tissue regeneration. Nowadays, β-TCP has been synthetized by different methods that allow obtaining different morphologies with chemical compositions similar to the bone tissue, broadening the possibilities of use. In this work, β-TCP powders were obtained using two different routes: mechanosynthesis and sol–gel. Results shown that both methods had significant effects on morphology and size particle of the obtained powders. The average size particles obtained using mechanosynthesis at 24 and 12h of milling time were 1000 and 170nm, respectively. The average size particles of the powders fabricated using sol–gel was 350nm, and the average powder particle size of the sigma reagent was 1450nm. Besides, sol–gel and sigma reagent powders were observed residual phases, instead mechanosynthesis shown only tricalcium phosphate beta phase. The formation of agglomerates with different sizes was observed in both methods by sol–gel and mechanosynthesis.

In Vivo Evaluation of 3D-Printed Polycaprolactone Scaffold Implantation Combined with β-TCP Powder for Alveolar Bone Augmentation in a Beagle Defect Model

Insufficient bone volume is one of the major challenges encountered by dentists after dental implant placement. This study aimed to evaluate the efficacy of a customized three-dimensional polycaprolactone (3D PCL) scaffold implant fabricated with a 3D bio-printing system to facilitate rapid alveolar bone regeneration. Saddle-type bone defects were surgically created on the healed site after extracting premolars from the mandibles of four beagle dogs. The defects were radiologically examined using computed tomography for designing a customized 3D PCL scaffold block to fit the defect site. After fabricating 3D PCL scaffolds using rapid prototyping, the scaffolds were implanted into the alveolar bone defects along with β-tricalcium phosphate powder. In vivo analysis showed that the PCL blocks maintained the physical space and bone conductivity around the defects. In addition, no inflammatory infiltrates were observed around the scaffolds. However, new bone formation occurred adjacent to the scaffolds, rather than directly in contact with them. More new bone was observed around PCL blocks with 400/1200 lattices than around blocks with 400/400 lattices, but the difference was not significant. These results indicated the potential of 3D-printed porous PCL scaffolds to promote alveolar bone regeneration for defect healing in dentistry.

Preparation and characterization of gelatin-chitosan-nanoβ-TCP based scaffold for orthopaedic application

The primary aim of this study was to fabricate gelatin/chitosan/β-TCP (GCT) composite scaffold to improve its compressive mechanical behaviour and in-vivo biocompatibility with predictable degradation rate. Beta tricalcium phosphate (β-TCP) powder was synthesized in size range between 70–100 nm using aqueous precipitation route at a fixed Ca/P molar ratio of 1.5:1 at pH 10 and after subsequent heat treatment of as precipitated powder at 800 °C for 4 hours. The composite scaffolds were fabricated using solid-liquid phase separation of the slurry containing gelatin, chitosan, β-tricalcium phosphate in varying proportion and subsequent lyophilisation of the phase separated mixture. The prepared scaffolds exhibited high porosity (>80%) with pore sizes ranging between 78–382 μm as determined using Hg-porosimetry. SEM result revealed that incorporation of β-TCP to the extent of 30 wt% resulted in well-shaped and uniformly distributed interconnected pores of average pore size of 120 ± 18.6 μm in it. Compressive strength of the scaffolds was increased from 0.8 MPa to 2.45 MPa on increase in β-TCP content from 10 wt%–30 wt% in the prepared scaffold. Human Umbilical Cord derived mesenchymal stem cells (MSCs) exhibited higher degree of lamellopodia and fillopodia extensions and better spreading behaviour onto GCT30 scaffold. MTT assay and immunocytochemistry studies with cultured MSCs revealed that GCT30 scaffolds were more conducive to MSC's proliferation and differentiation into osteoblast lineage. In vivo implantation of GCT30 scaffold subcutaneously into mice did not indicate any significant inflammatory reaction, but ongoing vascularization.