Surface Modification of Multilayer Coatings Ti-Al-Cr and Hydroxyapatite on Calcium Phosphate Cement with Sol-Gel Method

Dental implants based on metal still has weakness. New development is currently developed with the surface multilayer coatings Ti-Al-Cr and hydroxyapatite on calcium phosphate cement for dental implant application. Objective: to analyze the thickness of multilayer coating alloy Ti-Al-Cr and hydroxyapatite on CPC synthesis by sol-gel method. Methods: Scanning electron microscopy (SEM) was conducted to analyze the thickness and morphology of microstructure layer formed on CPC. Result: SEM showed that coating Ti-Al-Cr sucessfully formed 1 µm of thickness and 10 µm of hydroxyapatite. Conclusion: The innovation of modification surface multilayer coatings Ti-Al-Cr and hydroxyapatite on CPC was successfully done by sol-gel method with a variety thickness

The effect of light source distance on diametral tensile strength of nano particle composite

The use of nano particle composite in posterior region is somehow difficult due to the limited space to place the light source as close as possible to the restorative material. The distance between the light source and restorative material surface leads to decreased light intensity that causing inadequate polymerization. The inadequate polymerization affects the composite diametral tensile strength. Two types of nano particle composite, i.e. FiltekTM Z-350 and Ceram-XTM were tested for their diametral tensile strength, which is affected by the distance of the light source from the composite material surface. Some cylindrical specimens were exposed to light with various distances from the light source, i.e. 0, 1, 2, 3, 4, and 5 mm from the specimen surface. From the six distance variations tested the diametral tensile strength of Filtek Z-350 is 64.09-58.20 MPa with the significant result in 2, 3, 4 and 5 mm distances; and the diametral strenght of Ceram-X is 47.52-42.20 MPa with the significant result in 2, 3, 4 and 5 mm distances. The results of this study show that the increased distance of the light source from the nano particle composite restorative material leads to decreased diametral strength of the two nano particle composites tested

The effect of ZrCl4, Al(NO3)3 and Na2SiO3 precursors concentration on particle size as dental composites filler through spray pyrolysis method

ABSTRACT Introduction: one of the important components in dental composites is a filler which can be made through various methods, including spray pyrolysis. In the spray pyrolysis method, some factors determine the size and morphology of the resulting filler particles, one of which is the concentration of precursors. This study aimed to analyze the effect of precursor concentration on the particle size produced using the spray pyrolysis method. Methods: in this experimental laboratory study, zirconia-alumina-silica particles were synthesized using the spray pyrolysis method. The precursor solution consisted of ZrCl4, Al (NO3)3, and Na2SiO3 with a concentration variation of (0.1; 0.2; and 0.3) M. The furnace temperature was set at 750°C, and the electric precipitator temperature was 100°C with a feed rate of 3L/min. Then, the tests performed were using PSA (Particle Size Analyzer), and XRF (X-Ray Fluorescence). Results: The results showed that the best zirconia alumina silica filler particle with the smallest size is the result with a concentration of 0.1 M and its size was 618.6 nm. The particle size for 0.2 M was 911.9 nm and 1799.4 nm for 0.3 M.  According to XRF test results the zirconia alumina silica filler system contains all the precursor elements. Conclusions: The effect of precursor concentration on the particle size produced using the spray pyrolysis method showed that the smaller the precursor concentration used, the smaller the particle size produced. The best results from synthesizing a filler system with a concentration of 0.1 M precursor solution. All the results are in submicron and micron size, and could be used as the component of dental composites. Keywords: precursors concentration, particle size, spray pyrolysis, dental composites fille

Analisis Mikrostruktur Partikel Zirkoniakalsia-silika (ZrO 2 -CaO-SiO ) Dari Pasir Zirkon Alam Indonesia Menggunakan Metode Spray Pyrolysis

Indonesian Natural Sand, Zircon, is an Indonesia’s natural resource that contains zirconia, silica, titania and alumina. In Dentistry, zirconia as one of the content in natural zircon sand, have the potential to be the material for filler composites. The purpose of this research was to analyze the Zirconia-Calcium-Silicate Particle (ZrO2CaO-SiO2) synthesized from Indonesia natural sand, zircon, in microstructural way. Methods: By synthesizing ZirconiaCalcium-Silicate particle (ZrO2-CaO-SiO2) from Indonesia natural zircon sand, using spray pyrolysis method. A precursor solution that is used consists of zirconil nitrate (Zr (NO3) 2), sodium silicate (Na2SiO3), and calcium hydroxide (Ca (OH) 2). Variations in the temperature of the reactor that are used were 4000C, 4500C, and 5000C with a feed rate of 6 L / min and a piezoelectric frequency of 1.7 MHz. Result showed  that the better content in zirconia-calcium-silicate is the one  that was synthesized at a temperature of 4500C, based on the results of EDS, SEM and XRD. The composition that is obtained in the zirconia-calcium-silicate particle has a ratio of 1: 14: 4 with the size of 500-1000nm, and has a tetragonal crystal zirconium silicate structure and dicalcium monoclinic silicate. From this research it can be concluded that the result that was synthesized at a temperature of 4500C is adequate to use as a filler based on the characterization result of SEM and XRD

<strong>Effect of 3-methacryloxypropyltrimethoxysilane on diametral tensile strength of rice husk silica-based dental composite </strong>

ABSTRACT Introduction: Rice husk silica has been studied as a filler in dental composite, however, the mechanical properties of the resulting composites are below the commercial due to the poor surface modification between silica and resin matrix. 3-methacryloxyprpyltrimethoxysilane (MPTS) is one of the coupling agents that are effective to modify the silica surface. The purpose of this study to analyze the effect of MPTS on the diametral tensile strength (DTS) of the self-made composite using rice husk silica.  Methods: The research type of this study was an experimental research laboratory. The samples (26 samples) were divided into two groups, namely the test group (using MPTS-modified silica) and the control group (using non-modified silica). The samples were cylindrical in shape with a diameter of 6.0 ± 0.1 mm and a height of 3.0 ± 0.1 mm according to ANSI/ADAS No. 27, 1993 and ISO 4049, 1988. The Fourier Transform Infrared (FTIR), HORIBA, was used to characterize the MPTS grafting on the silica surface. The DTS value is measured by Universal Testing Machine (UTM), Lloyd LRX Plus. Results: FTIR presents the additional peak of carboxyl and methacryloyl group at 1716, 1555, and 1410 cm-1 wavenumber, respectively in MPTS-modified silica. The DTS value of the test group was 43.40 ± 4.43 MPa and the control group was 25.80 ± 2.63 MPa. The test group was significantly higher than the control group (p-value = 0.001). Conclusion: The MPTS is effective to enhance the DTS value of rice husk silica-based composite. Keywords: Rice husk silica; dental composite; diametral tensile strength; 3-methacryloxypropyltrimethoxysilane

Preparation of micro-calcite powder using fine-bubble assisted carbonation as toothpaste material

ABSTRACT Introduction: Calcite (CaCO3) is typically used in commercial toothpaste with particle size ranges from 1-12 μm. In the latest study, calcite was synthesized by using Ca(OH)2 precursor from natural resources However, the resulting particle size does not match the size of the toothpaste filler. This study aims to prepare micro-calcite via fine-bubble assisted carbonation as toothpaste material. Methods: The calcite powder was prepared from Ca(OH)2 analytical grade powder utilizing the fine-bubble carbonation process with the Ca(OH)2 concentration and initial pH variation. The study was started by making a Ca(OH)2 suspension with a concentration of 0.25, 0.5, 0.75, 1 and 1.25 M using 2.000 ml methanol as a solvent. 0.5 M NaH2PO4 solutions were utilized to adjust the initial pH of 0.5 M Ca(OH)2 suspension into 8, 9, and 10. The suspensions were aerated using CO2 fine-bubble for two hours to produce CaCO3 samples. All precipitated CaCO3 particles were characterized by PSA, Zeta-Potential, and FTIR measurements. Results: The calcite phase was identified from the FTIR transmittance. Aragonite or vaterite phase was not observed in the samples. PSA result shows the size of CaCO3 particles from samples 0.25 M to 1.25 M are as follows 3.03, 3.23, 2.79, 3.70, 0.99 μm respectively. Meanwhile, the particle sizes of CaCO3 in samples with a pH of 8, 9 and 10 are 3.00, 2.03 and 2.50 μm respectively. The zeta potential shows the value ranges from -23.2 mV to -11.9 mV, indicating fair dispersion ability. Conclusion: The fine bubble assisted carbonation method in this study helps in producing calcite in micron size that could be used as alternative fillers for toothpaste. Keywords: calcite, fine-bubble, carbonation, particle size, toothpast