Arief Cahyanto

Fabrication of bone cement that fully transforms to carbonate apatite

The objective of this study was to fabricate a type of bone cement that could fully transform to carbonate apatite (CO3Ap) in physiological conditions. A combination of calcium carbonate (CaCO3) and dicalcium phosphate anhydrous was chosen as the powder phase and mixed with one of three kinds of sodium phosphate solutions: NaH2PO4, Na2HPO4, or Na3PO4. The cement that fully transformed to CO3Ap was fabricated using vaterite, instead of calcite, as a CaCO3 source. Their stability in aqueous solutions was different, regardless of the type of sodium phosphate solution. Rate of transformation to CO3Ap in descending order was Na3PO4>Na2HPO4>NaH2PO4. Transformation rate could be affected by the pH of solution. Results of this study showed that it was advantageous to use vaterite to fabricate CO3Ap-forming cement.

Basic Properties of PMMA Reinforced Using Ceramics Particles of ZrO2-Al2O3-SiO2 Coated with Two Types of Coupling Agents

In this study, novel composites materials composed of polymethyl methacrylate (PMMA) reinforced ZrO2-Al2O3-SiO2 filler system were developed. Zirconia-alumina-silica filler system were synthesized through sol-gel technique. Chitosan and trimethoxypropilsilane (TMPS) were used to modify the composites system. The resulting composites material were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD) and hardness test. SEM images displayed the composites particles in nanometer size with minor agglomeration. The XRD results revealed the presence of cubic and tetragonal phase of zirconia and also monoclinic silica phases in the composites system. These crystallographic characteristic could affect the mechanical properties of the composites. The hardness value for un-modified composites was 15.27 ± 0.25 VHN and for TMPS 19.43 ± 1.89 VHN and chitosan modification 18.75 ± 2.05 VHN, respectively. Therefore, these novel composites materials composed of PMMA reinforced filler system of zirconia-alumina-silica would provide the potential to apply in dental technology.

Basic Properties of Carbonate Apatite Cement Consisting of Vaterite and Dicalcium Phosphate Anhydrous

The aim of the present study is to fabricate bone cement that could transform to carbonate apatite (CO3Ap) completely at body temperature. The powder phase of vaterite and dicalcium phosphate anhydrous (DCPA) was mixed with 0.8 mol/L of NaH2PO4, Na2HPO4, and Na3PO4 aqueous solution, respectively, with liquid to powder ratio (L/P ratio) of 0.45, 0.55, and 0.65. The paste was packed into split stainless steel mold, covered with the glass slide and kept at 37°C and 100% relative humidity for up to 96 hours (h). XRD analysis revealed that the cement became pure CO3Ap within 24 h for Na3PO4, 72 h for Na2HPO4, and 96 h for NaH2PO4, respectively. FT-IR results showed that all of the obtained specimens could be assigned to B-type CO3Ap. CHN analysis showed the carbonate content of the specimen were 10.4 ± 0.3% for NaH2PO4, 11.3 ± 0.7% for Na2HPO4, and 11.8 ± 0.4% for Na3PO4, respectively. Diametral tensile strength of the set CO3Ap cement was 1.95 ± 0.42 MPa for NaH2PO4, 2.53 ± 0.53 MPa for Na2HPO4, and 3.45 ± 1.53 MPa for Na3PO4, respectively. The set CO3Ap cement had low crystallinity similar to bone apatite since it was synthesized at body temperature. We concluded, therefore, that CO3Ap cement prepared from the present method has higher possibility to be used as an ideal bone replacement.

Hardness Evaluation of Dental Composite with Ceramic Fillers

In this study, new dental composites materials were developed. The two composites systems composed of zirconia (ZrO2), alumina (Al2O3) and silica (SiO2) (composites A) and zirconia (ZrO2), calcium (CaO), and silica (SiO2) (composites B) were synthesized through sol-gel method. These two systems were combined with urethane dimethacrylate and tetraethylene glycol dimethacrylate with 1% chitosan as coupling agent to build up the dental composites material. The resulting composites were subject to evaluation by microvickers hardness test and X-ray diffraction. The microvickers hardness test revealed that the hardness value for composites A and B were 24.48 and 21.9 VHN, respectively. Furthermore, the data were submitted to t-test (α=0,01) and it showed t count of both samples was 0,871 which means between the -t1-½α< t <t1-½α thus showing statistically the same average hardness value of both samples. Eventually, the new dental composites could be anticipated to apply in dental composites filler. The hardness results support the XRD result revealed that tetragonal crystal phase will help the transformation toughening mechanism and cubical crystal phase of zirconium dioxide. Both of the crystal phases were formed to stabilize the zirconia.

Fabrication of hydroxyapatite from fish bones waste using reflux method

The aim of this present study was to investigate the fabrication of hydroxyapatites, which were synthesized from fish bone wastes using reflux method. The fish bone wastes collected from the restaurant were brushed and boiled at 100°C for 10 minutes to remove debris and fat. After drying, the fish bones were crushed, and ball milled into a fine powder. The fish bone wastes were then processed by refluxing using KOH and H3PO4 solutions. The samples were calcined at 900°C and characterized by X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectrometry (FT-IR). The XRD pattern of samples after treatment revealed that the peak of hydroxyapatite was observed and the bands of OH- and PO4 3- were observed by FT-IR. The scanning electron microscope evaluation of sample showed the entangled crystal and porous structure of hydroxyapatite. In conclusion, the hydroxyapatite was successfully synthesized from fish bone wastes using reflux method.

Transformation of Apatite Cement to B-Type Carbonate Apatite Using Different Atmosphere

Apatite cement (AC) is a breakthrough in biomaterials for the reconstruction of the bone defect. However, the replacement of AC to bone up to the present time is still controversial for researchers. Several researchers have reported that AC was replaced by bone while others claimed replacement was limited. The aim of this study is to investigate the transformation mechanism of AC to B-type carbonate apatite (CO3Ap) using different atmosphere. An in vitro study mimicking the body environment was employed in order to examine the effect of setting atmosphere on the composition of set AC. An equimolar of tetracalcium phosphate (TTCP; Ca4(PO4)2O) and dicalcium phosphate anhydrous (DCPA; CaHPO4) mixed with distilled water was enabled to harden at 37°C and 100% of relative humidity under presence of 5% CO2, 100% CO2, and 100% N2 atmospheres. XRD and FT-IR analyses revealed that in the presence of 100% CO2 and 5% CO2, B-type CO3Ap could be determined and only small amounts of TTCP remained unreacted. On the contrary, in the presence of 100% N2, the CO32- bands could not be detected and larger amount of TTCP remained unreacted compared to 5% CO2and 100% CO2 atmospheres. SEM morphology showed that the microstructure of AC was entangled and locked to each other. In addition, the small needle like crystals appeared in the surface of 100% N2, similar to hydroxyapatite. We concluded that the CO32- ions incorporated in AC during setting reaction may be one of the essential factors for CO3Ap formation.

Effect of Particle Size on Carbonate Apatite Cement Properties Consisting of Calcite (or Vaterite) and Dicalcium Phosphate Anhydrous

Calcium carbonate (CaCO3) has been known as one of the components of carbonate apatite (CO3Ap) cement. Calcite is one of the polymorph of CaCO3 with big particle size and excellent stability. In contrast, vaterite has small particle size and a metastable phase. To discover the effect of particle size on the properties of CO3Ap cement, this study investigated the different particle size of vaterite; calcite from vaterite, which has almost similar particle size and shape with vaterite; grounded calcite and ungrounded calcite. The powder phase of calcite or vaterite combined with dicalcium phosphate anhydrous (DCPA) was mixed with 0.8 mol/L of Na2HPO4 solution in 0.45 liquid to powder ratio. The paste was packed into a split stainless steel mold, covered with glass slide and kept at 37°C and 100% relative humidity for a period of time. XRD and FT-IR analysis revealed that CO3Ap cement consisted of vaterite and DCPA transformed to pure B-type CO3Ap in 72 hours while CO3Ap cement that consisted of calcite with different particle size was not completely transformed to CO3Ap even until 240 hours. We concluded that CO3Ap cement consisted of vaterite with small particle size and metastable phase properties is more effective as starting material due to its fast transformation to CO3Ap.

Composition and Functional Groups Evaluation of Indonesian Grey Portland Cement as Material for Dental Application

Tricalcium silicates cement known as Mineral Trioxide Aggregate (MTA) was one of the influential materials in endodontics. At recent, MTA in dental application play an essential role in endodontics treatment due to its potential to regenerate tertiary dentine, apexification, and seal perforated root. However, MTA for dental application is still expensive. Portland cement has similarities with the MTA, especially portland cement fabricated in Indonesia. The purpose of this study is to investigate the composition and functional groups of tricalcium silicate from portland cement that fabricated in Indonesia. The Indonesian grey portland cement powder/portland cement type I (SNI-15-7064-2014) was used as a sample and commercialized MTA from Tehnodent (Rootdent) was used as a control for comparison. Powder and control samples were evaluated using X-ray fluorescence spectrometry (XRF) for composition test and Fourier-transform infrared spectroscopy (FTIR) for functional group analyses. The XRF evaluation showed that the composition and concentration of Indonesian grey portland cement powder almost has similarity with commercial MTA. Moreover, the Indonesian grey portland cement powder has higher Calcium and Silicon ions compared to MTA. The FTIR analyses revealed that the calcium silicate groups were detected. In conclusion, the Indonesian grey portland cement powder has high similarity to MTA, therefore, it has a possibility to be used as tricalcium silicate cement for MTA substitution. Further study is awaited based on this initial finding found in this study.

Surface Characterization of Dental Porcelain Made from Sumatera Natural Sand

This research reported hardness and porosity morphology results on five different sintering temperatures as surface characterization of dental porcelain made from Sumateran natural sand mixture composition to prevent excessive wear. Porosity morphology was characterized with JEOL Scanning Electron Microscope (SEM), while the average hardness of each 5 different indented areas was performed with 1000 gr load for 15 seconds using Zwick Roell Vickers Hardness Tester. The result of this study shows that the higher sintering temperature correlates to higher hardness number. SEM analysis indicate less porosity appear in the samples sintered in higher temperature. By modifying the mixture, this study has significantly lowered the hardness number results compared to our previous research samples yielded 936,06 VHN. It can be concluded that positive correlation between higher temperature and hardness emerged from the surface characterization results of the dental porcelain made from Sumatera natural sand. In contrasts the porosity appear to be less developed in higher temperature. However, cracks and pores followed the indentation as in common ceramic products. Further improvement is needed with finding the optimum temperature of desired hardness number and predictable porosity, which resemble tooth enamel.

Compressive Strength Evaluation and Phase Analysis of Pulp Capping Materials Based on Carbonate Apatite-SCPC Using Different Concentration of SCPC and Calcium Hydroxide

The mechanical strength of pulp capping material based on carbonate apatite and silica calcium-phosphate composite (CO3Ap-SCPC) is one of the key factors for the success of the material in protecting the vitality of the pulp during the formation of apatite and dentin reparative. Modifying the material in the powder phase was known to increase the mechanical strength. The purpose of this study was to determine whether the addition of SCPC and calcium hydroxide in pulp capping materials based on CO3Ap-SCPC would affect the compressive strength of this pulp capping material. In this study, three cement groups were used, each group consisted of dicalcium phosphate anhydrous and vaterite which added by SCPC concentration 0%, 5% and 10% and calcium hydroxide concentration 0%, 5% and 10%, respectively. All groups were tested by a compressive strength test and X-Ray diffraction (XRD) for phase analysis. The mean value of compressive strength with addition of 0% SCPC and 10% Ca(OH)2 was 16.54 ± 1.35 MPa, addition of 5% SCPC and 5% Ca(OH)2 of 18.55 ± 2.81 MPa, addition of 10% SCPC and 0% Ca(OH)2 was 9.22 ± 1.21 MPa. The addition of SCPC and Ca(OH)2 show statistically significant difference in compressive strength (p<0.05). The XRD analysis of the highest compressive strength revealed that the apatite crystal was successfully formed. It can be concluded that incorporated specific amount of SCPC and Ca(OH)2 could improve the mechanical strength and the apatite formation of the CO3Ap-SCPC pulp capping material.