Papers by Keyword: Bioceramic

Abstract: Dolomite is a raw carbonate mineral rich in contents with calcium, magnesium and oxide compounds also including other minor impurities from other compounds. It could be easily found in sedimentary rock which is most likely known as dolostone associated with limestone and chalk carbonates. This mineral has been used in a variety of industries including agricultural, metallurgy, constructions, biomass and others. Currently, there are abundant sources of local dolomite minerals but have very limited applications when compared to other types of carbonate minerals. This was contributed by the lack of basic technical information on dolomite properties and no extensive research has been done to evaluate the new potential of this mineral. Therefore, this paper made a brief review on the important characteristics, properties and thermal behavior of dolomite and based on these findings discussed the dolomite's suitability and potential to be used as bioceramics and in biomedical applications.

Abstract: Carbonated hydroxyapatite (CHA), with a chemical composition close to the mineral found in human bone, represented higher solubility than stoichiometric hydroxyapatite (HA). Therefore, the B-type CHA is commonly used for bone tissue engineering. This study fabricated B-type CHA using Indonesian eggshells from chicken, organic chicken, and duck because of the high calcium carbonate (CaCO₃) content (94%). A co-precipitation method was used for synthesizing CHA. The physicochemical properties of the CHA were characterized using Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy (SEM-EDS), X-Ray Diffractometer (XRD), and Fourier Transform Infrared Spectroscopy (FTIR). Based on FTIR results for CHA, the stretching functional groups of B-type CO₃ were detected at 1452-1453 cm^-1, 1417-1418 cm^-1, and 873-874 cm^-1, which indicated the formation of B-type CHA. Meanwhile, CHA from organic chicken eggshells had low crystalline properties and the best morphology due to a more homogeneous and uniform agglomeration. More specifically, CHA based on organic chicken eggshells has a Ca/P molar ratio following natural human bone, which is 1.71. Therefore, all B-type CHA samples are candidates in bioceramic materials for bone tissue engineering applications.

Abstract: In this work, bioceramic hydroxyapatite (HAp) was synthesized based on sand lobster shells (Panulirs homarus) as a source of calcium using the precipitation method. Sand lobster shell powder was calcinated with temperature variations of 600, 800, and 1000 °C for 6 hours. The effect of calcination temperature on sand lobster shell powder was characterized to determine the optimal temperature for the synthesis of HAp. Based on the XRF (X-Ray Fluorescence) characterization, the highest calcium content (Ca) was 93% at a calcination temperature of 1000 ^oC. This result was supported by FTIR (Fourier Transform Infrared) spectrum that increasing the calcination temperature will reduce the intensity of carbonate ion (CO₃^2-). These results showed that 1000 °C was the best calcination temperature on sand lobster shells to synthesize HAp. The characterization result of HAp using EDX (Energy Dispersive X-Ray) revealed that the molar ratio of Ca/P was 1.73. The FTIR and XRD (X-Ray Diffractometer) spectral pattern indicate that HAp had been successfully synthesized with minor-TCP, which is also a calcium phosphate with high biocompatibility.

Abstract: B-type carbonated hydroxyapatite (C_BHA) is potentially an excellent biodegradable bioceramic for bone repair. However, conventional sintering results in formation of undesired phases. Therefore, microwave sintering of C_BHA was investigated to assess the possibility to reduce formation of unwanted phases. Pellets with 0.8 mol% of B-type carbonate were sintered in a multimode instrumented cavity under static air with short thermal cycles. They were prepared from a C_BHA powder alone and from a mixture of C_BHA and carbon powder to generate a local in-situ CO₂ atmosphere. XRD, FT-IR, SEM and BET analyses indicated that C_BHA densification with increase temperature lead to decomposition into apatite. The addition of carbon powder to the C_BHA that generate a CO₂-rich atmosphere around the samples did not prevent the decomposition. Efficient control of temperature and atmosphere composition is required to improve microwave sintering of C_BHA bioceramics.

Abstract: This paper highlights the study on effect of sintering temperature on the morphologies and compressive strength of zirconia ceramics doped with calcium oxide (CaO) as stabiliser to enhance the zirconia structure undergo sudden phase transformation. CaO reportedly has good stability in cubic phase at all temperature, which open up a new possibility for new material to evolve for zirconia ceramic dental application. CaO synthesis from calcium nitrate tetrahydrate (Ca(NO₃)₂.4H₂O) is used as metal precursor to produce Calcia-Sabilized Zirconia (Ca-SZ). 8 wt. % of Ca(NO₃)₂.4H₂O and 92 wt. % of zirconium oxide (ZrO₂) mixed and stirred together with ethanol as solvent and sintered at temperatures 1200, 1300 and 1400°C. Surface morphologies are investigated by Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX) element analysis, X-ray Diffraction (XRD) for composition studies, as well as compressive strength to figure out the mechanical properties of Ca-SZ sample. Increment in sintering temperature enhance the surface morphologies, the phase of Ca-SZ become intensified and transformed from monoclinic to tetragonal ZrO₂ also flexural strength increases as well. The compressive strength recorded the highest value of 4537 MPa for Ca-SZ at temperature of 1400°C. The optimal temperature of Ca-SZ suitable for dental application was 1400°C due to the good morphologies and mechanical properties suitable for teeth restoration. The development of Ca-SZ can establish a pathway as an alternative material for dental applications.

Abstract: The aim of this study was to upscale the production of calcium oxide (CaO) derived from cockle shells using an improved protocol and determine its purity, as well as to study the hardness of the new, improved calcia stabilized zirconia (Ca-SZ). A mixture of diluted cockle shells powder with hydrochloric acid solutions (HCl) was stirred to obtain calcium chloride (CaCl₂). The homogenous CaCO₃ solutions were obtained by mixing CaCl₂ solution with potassium carbonate (KCO₃) using upscaled mechanochemical synthesis process. Then, CaCO₃ powder underwent calcination process at a temperature in range of 300°C – 550°C to obtain CaO powders. CaO showed the result under FESEM analysis as a spherical shape with crystal-like structure as well dispersed with no visible agglomeration. The yield production of CaO obtained was approximately about 5.0g which was upgraded from a previous study. The morphologies of Ca-SZ were observed at three different sintering temperatures at 1200°C, 1300°C and 1400°C were selected in order to understand the morphological and mechanical properties of Ca-SZ after incorporating 8wt% of CaO powders derived from cockle shells. The Ca-SZ pellets were then characterized using Field Emission Scanning Electron Microscopy (FESEM) and Vickers Hardness Test to ensure the effectiveness of CaO powder in fabricating Calcia-Stabilized Zirconia (Ca-SZ). As a result, sintered Ca-SZ at 1400°C showed the most promising performance for nano-CaO act as a stabilizer as it has the highest hardness at 590.03MPa with significantly difference (p<0.05) among all sintered Ca-SZ specimens. Therefore, these findings revealed that by adjusting the previous protocol, upscaling of a pure CaO may be synthesized using natural Ca source from cockle shells. The fabricated Ca-SZ showed a significantly lower hardness when sintered at 1400°C, which may be easier for machining.

Abstract: Polymer matrix composites are suitable materials for medical applications, such as denture base resin polymethyl methacrylate (PMMA). This includes light weight and high strength. This paper describes the effect of selected weight fractions (1, 2, 3, 4 & 5) % wt of nano(Alumina AL2O3, Zirconia ZrO2, Hydroxyapatite HA and Halloysite nanoClay) reinforcements on the biopolymer matrix (PMMA). Some tribology tests were used to evaluate the prepared system (impact strength, hardness surface, and wear rate) tests. The samples were fabricated by (Hand Lay-Up) with different particle reinforcement percentages. All tests were accomplished at room temperature, and samples were developed according to the ASTM standard. The weight fraction of (4% for AL₂O₃, 4% for ZrO₂, 3% for HA and 5% for Clay) nanoparticles are the best results that appeared in the work.

Abstract: Bioactive apatite, which is hydroxyapatite (HAP) with the chemical formula of Ca₁₀(PO₄)₆(OH)₂ have been extensively investigated for biomedical applications in bone and teeth implants due to its biocompatibility characteristics has similar physical-chemical characteristics with human bone. The issues to be highlighted here is to explore the potential of using food waste from goat bone to produce useful natural HAP. This study is to extract natural HAP powder from goat bone waste. The extraction process involved cleaning and boiling process, drying process, crushing, grinding and milling to obtain micron size powder of goat bone and joint. The sample then underwent a calcination process with 900°C, 1000°C, and 1100°C for goat bone and 900°C for goat joint with 3 hours holding time. The characteristic of produced HAP powder was characterised with Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectroscopy (EDS), X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). The in vitro testing of HAP completed by using Simulated Body Fluid (SBF) and SEM to observe the microstructure of apatite formation. The XRD and EDS results show the HAP crystallinity and Ca/P ratio increase with the increasing of calcination temperature for bone. The bone-like apatite formation appeared in the goat bone and joint sample with calcination temperature 900°C, 1000°C, and 1100°C. The optimum hydroxyapatite is from goat bone sample with calcination temperature 1100°C due to the apatite growth fully cover the surface of the sample with a needle shape structure of the cauliflower structure.

Abstract: The aim of this study is to investigate the behavior of osteoclast cells response on dicalcium phosphate dihydrate (DCPD) layer-coated β-TCP granules. β-TCP granules with 300-600 μm were exposed to acidic calcium phosphate solution for 30 mins in order to get 10 mol% DCPD layer-coated β-TCP granular. DCPD free-coated β-TCP granular had used as control specimen. Both specimens were implant in 9 mm of rat calvarial bone defect for 4 weeks. After 4 weeks, the block section of rat calvarial containing specimen were removed for Tatrate-Resistance Acid Phosphatase (TRAP) analysis. Results of TRAP staining reveal that the number of osteoclast cells attached on 10 mol% layer-coated β-TCP granular is higher than DCPD free-coated β-TCP granular. Since remodeling of new bone formation involved simultaneous osteoclast and osteoblast cells response, therefore, the results obtained in this study indicated that the presence of DCPD layer-coated on β-TCP granular helps to improve osteoclast cells response that contribute in stimulating new bone formation.

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.