Papers by Keyword: Carbonate Apatite

Abstract: In this study, carbonate apatite [Ca_10-x(PO₄)_6-y(CO₃)_z(OH)_2-x-y-z, CHAp], a bone substitute material, was coated on roughened titanium through a sol-gel hydrothermal method. The sol-gel process was used to prepare calcium tartaric complexes, which were then subsequently hydrothermally treated on titanium in the presence of sodium hydroxide, and sodium hydrogen phosphate. The results showed that carbonate apatite, composed of nanosized fibers, was evenly deposited across the titanium surface. This coating resulted in a lower surface roughness (Ra) value of 1.31 μm compared to 3.98 μm for uncoated titanium. Additionally, the carbonate apatite coating decreased the contact angles of the titanium surface, thereby significantly enhancing cell attachment and migration compared to the uncoated surface. These results could be valuable for further evaluation of this coating in biomedical applications.

Abstract: Bioceramics play a key role in endodontics, mostly in surgical endodontics and difficult cases of root canal treatment. Carbonate apatite (CO₃Ap) is the natural composition of dental and bone. The endodontic sealer is used in the obturation phase of endodontic treatment, which requires sealing ability and bioactivity to promote osseous repair of teeth and alveolar bone. CO₃Ap crystal formation is essential for endodontics sealer as a bioceramic sealer. This study aims to investigate the crystal characterization of CO₃Ap through X-Ray diffraction (XRD) and scanning electron microscope (SEM). The bioceramics endodontic sealer comprises dicalcium phosphate anhydrous (DCPA), vaterite, and Ca(OH)₂. The powder cement ratio divided into 60% DCPA : 30% vaterite: 10% Ca(OH)₂. Powder cement was mixed with 0.2 mol/L Na₂HPO₄ added by 1% sodium carboxymethylcellulose and 32μg thymoquinone as an aqueous solution at the liquid to powder ratio of 0.6 and set at 37°C and 100% of relative humidity for 72h. XRD result showed that all precursor materials transformed into CO₃Ap after 72h treatment. SEM image showed coral-like CO₃Ap morphology that is characteristic of CO₃Ap. The initial results of novel CO₃Ap endodontic sealers show that crystal formation occurs and has potential to be used as an endodontic sealer.

Abstract: The development of magnesium-based materials, applied for a biodegradable implant, attracted the attention of many researchers. In this research, the initial development of the Mg/carbonate apatite (CA) miniplate was carried out. The miniplate Mg/5CA is fabricated through powder metallurgy and is followed by a sintering process. Pure magnesium is also fabricated with the same process and is used as a reference. The visual form, microstructure (OM), bending test and corrosion test of miniplate were investigated. The results showed that the visual form of the Mg/5CA miniplate is still not perfect. Flexural stress, flexural strain, and elasticity modulus were obtained at 34.02 MPa, 0.9%, and 3.53 GPa, respectively. The corrosion rate is obtained at 12.64 mm/year. The compaction process of Mg/5CA powder followed by sintering is considered to be less appropriate. The addition of the extrusion process and/or the ECAP process in fabrication can be an option to improve its properties.

Abstract: Abstract. Various bioactive calcium phosphates such as hydroxyapatite (HA) and carbonate apatite (CO₃Ap) have been widely studied due to their biocompatibility and osteoconductivity when implanted into bone defects. CO₃Ap has the ability to adapt bone structure and induce bone regeneration; so that it can be categorized as resorbable bioactive materials. CO₃Ap induced much stronger response such as cell adhesion and actin ring formation to osteoclast-like cells rather than HA. The aim of this study is to evaluate the bioactivity on zirconia (Y-TZP) coated with CO₃Ap using simulated body fluid (SBF). Twenty Y-TZP ZrO₂ disks with a 12-mm diameter and 1-mm thickness were employed as the samples. The disks were divided into two groups which the control group without CO₃Ap coating and tested group with CO₃Ap coating. Disks samples are dipped into CO₃Ap suspension for one minute and stored in 37°C incubator for 24 hours. The disks were soaked in SBF for 1, 4, and 7 day(s) at 36.5°C. The obtained apatite crystals were characterized by scanning electron microscopy (SEM). It was found that the apatite formation on the tested group was greater than the control group. The EDS pattern showed the presence of Ca and P on the control and tested group after SBF soaking, which indicate the apatite deposition on the disks’ surface. However, the Ca and P on the tested group was higher compared to the control group. The formation of apatite layer on the disks’ surface is bioactivity indicator of CO₃Ap.

Abstract: Bone defect is a common problem in the field of dentistry. The defect can be solved bytissue engineering. One component of tissue engineering is scaffold. Carbonate apatite is the main material used because it has an organic components similar to human bones. The carbonate apatite combined with gelatin and chitosan can be used as a scaffold for tissue engineering. The aim of thisstudy is to know the exact ratio of the carbonate apatite, chitosan-gelatine (CA:Ch-GEL) scaffold on the compressive strength and porosity size as biomaterial candidates in tissue engineering. Scaffold was synthesized from CA:Ch-GEL with different ratios of 50:50, 60:40, 70:30 and 80:20 withfreeze drying method. Fourier Transform Infared Spectroscopy (FTIR) was used CA:Ch-GEL scaffold functional group identification. Scaffold mechanical test was performed using an Autograph while a porosity test was performed using Scanning Electron Microscope. All data wereanalyzed by ANOVA followed by Tukey HSD test. Scaffold has a compressive strength ranges 4.02 - 11.35 MPa, with porous ranges 19,18 mm – 52,59 mm at 50:50, 60:40, 70:30 and 80:20 ratios. CA:Ch-GEL scaffold at all ratios can be used as biomaterials in tissue engineering

Abstract: Carbonate apatite is one of the most widely studied bioceramic material for its use as bone cement. On the previous study, it has already stated that CO₃Ap cement has good osteoconductivity which makes this cement could be replaced by bone. However, the mechanical strength of CO₃Ap cement is still low. This low mechanical strength is estimated due to the high porosity and absence of organic components. The aim of this study is to improve the mechanical strength of the CO₃Ap cement reinforced by gelatin as an organic component with genipin as a cross-linking agent (Gelapin). The powder phase of vaterite and DCPA at weight ratio 40:60 were mixed with 0.2 mol/L Na₂HPO₄, 5% (w/v) gelatin, and 20% (v/v) genipin using 0.5 liquid to powder (L/P) ratio. The liquid phase ratios of Na₂HPO₄ and Gelapin were 50:50, 70:30, and 90:10. For control group, Gelapin were didn’t mixed in the liquid. Diametral tensile strength was improving and statistically significant (p<0.05) on set cement with 50:50 liquid ratio, the average value was 6.02 ± 0.14 MPa whereas the average value of the control group was only 3.10 ± 0.15 MPa. For this instance, gelatin serves a polymer matrix so the carbonate apatite crystallites could be well distributed within it which then gives more flexibility and resistance for the cement. On the other hand, genipin was also successfully cross-linked the gelatin. This study showed that by reinforcing CO₃Ap cement using genipin cross-linked gelatin might be a good candidate for a bone substitute material.

Abstract: Calcium phosphate biocomposites are candidate materials for bone tissue engineering due to their conductivity and biocompatibility. Calcium phosphate could be grown on collagen by precipitation method in long reaction time. Microwave irradiation is rapid method to assist precipitation by reducing reaction time. In order to study carbonated calcium phosphate precipitation on collagen and investigate the influence of microwave irradiation time, the carbonated calcium phosphate has been grown on collagen by microwave assisted precipitation method. The collagen sheets were soaked in carbonated calcium phosphate suspension prepared by using Ca(NO₃)₂.4H₂O, (NH₄)₂HPO₄, and NaHCO₃ as starting materials, then microwave irradiated at 270 Watt for 2 minutes, 8 minutes, and 16 minutes. X-ray powder diffraction (XRD) pattern shows the transformation of dicalcium phosphate dyhydrate to apatite crystal structure. Increase in irradiation time had increased crystallinity of carbonate apatite phase. FTIR spectrum had confirmed presence of collagen, phosphate, and carbonate functional group. Scanning electron micrograph showed the presence of collagen with pore, and the carbonated calcium phosphate could attach and be deposited onto collagen.

Abstract: Brushite cement has advantages such as fast setting, high reactivity and good injectability over apatitic cements. To induce the bioactivity of brushite cements, the goal was to convert it into a bone-like low crystalline carbonate apatite. To achieve this induced transformation, potassium and magnesium were used as dopants which were claimed to be effective in the literature. The cements were immersed for 2 periods of time: 1 day and 6 weeks in Tas-Simulated-Body-Fluid (Tas-SBF) due to its excellent biomimetic properties with its adjusted HCO3- and Cl- ionic rates according to human-blood-plasma. 5% of potassium (to calcium sites) seemed to be more effective over magnesium modification. The aim of this study is to define an optimal composition in terms of transforming brushite into apatite.

Abstract: The carbonate apatite (CO₃Ap) cement as an endodontic sealer play an essential role for endodontics treatment due to its potential to obturate root canal system as one of the most important part in endodontic treatment. Moreover, the CO₃Ap has probability of similarities with composition of root dentin. Recently, the setting time of commercial endodontic sealer has 4 hours to 1 day. Therefore, the aim of this present study is to evaluate setting time and to determine the functional group of the new material composition for endodontic sealer. CO₃Ap cement sealer was prepared by mixing dicalcium phosphate anhydrous (DCPA), vaterite and calcium hydroxide [Ca (OH)₂] with 0.2 mol/L Na₂HPO₄ containing 1% sodium carboxymethylcellulose (NaCMC) and 32 μg thymoquinone, with liquid to powder ratio of 0.6. The setting time was evaluated by Vicat needle method as describe on modification ISO 1566 for zinc phosphate cement. Five compositions of powder ratio were prepared in this study. The set CO₃Ap cement sample was evaluated by Fourier Transform Infrared Spectroscopy (FTIR) to define the functional group of the sample. Setting time evaluation indicated that the average setting time of CO₃Ap cement was 21 minutes of five compositions. The FTIR analyses revealed that the CO₃^2- groups were detected, so the results could determine as B-type CO₃Ap.The CO₃Ap cement was considered fast setting as an endodontic sealer compared to sealers made from other base and proven to have similarities with the components of root dentin.

Abstract: Appropriate biomaterial and controlled size particle are the important component to achieve effective delivery system. Reducing size of the particle is recommended because it can overcome the barriers during cellular uptake. Biomimetic carbonate apatite (CHA) is now considered as candidate for protein delivery because it has high affinity to protein, high biocompatibility and biodegradibility, and increases protein stability. In this study, nano-CHA was prepared and ovalbumin (OVA) protein was incorporated into the CHA particles.