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"Latar Belakang: Aplikasi Mineral Trioxide Aggregate (MTA) sebagai material bioaktif yang umum digunakan dalam upaya remineralisasi affected dentin memiliki peranan penting dalam preservasi jaringan gigi pada perawatan terapi pulpa vital, namun diketahui tidak dapat menghasilkan dentin dengan sifat mekanis menyerupai dentin sehat karena hanya menghasilkan remineralisasi ekstrafilbrillar. Carboxymethyl Chitosan (CMC) merupakan biomaterial alami yang dikembangkan sebagai analog protein non-kolagen pada dentin untuk menghambat laju presipitasi kalsium fosfat yang dihasilkan oleh interaksi antara material bioaktif dengan jaringan sehingga dapat memasuki ruang intrafibrillar kolagen. Tujuan: Mengetahui pengaruh penambahan CMC pada semen MTA terhadap perubahan karakteristik kristal hidroksiapatit dan kekerasan mikro dentin terdemineralisasi, yang diobservasi selama 14 hari periode remineralisasi. Metode: Remineralisasi dilakukan melalui aplikasi material MTA, MTA-CMC 5%, dan MTA-CMC 10% pada dasar kavitas sampel dentin terdemineralisasi. Akar gigi direndam selama 14 hari dalam cairan phosphate-buffered saline. Observasi karakteristik kristal hidroksiapatit dilakukan dengan alat uji X-ray Diffractomete dan perubahan kekerasan mikro dianalisis secara kuantitatif melalui uji Vickers Hardness.Hasil: Pembentukan kristal hidroksiapatit ditemukan pada sampel MTA dan MTA-CMC dengan derajat kristalinitas hidroksiapatit paling tinggi pada sampel MTA-CMC 10%. Kekerasan mikro dentin meningkat pada kelompok MTA-CMC 5% dan MTA-CMC 10% dibandingkan pada kelompok MTA. Kesimpulan: Aplikasi modifikasi material Mineral Trioxide Aggregate dengan Carboxymethyl Chitosan selama 14 hari menginisasi terbentuknya fase mineral hidroksiapatit dan meningkatkan derajat kristalinitas hidroksiapatit pada dentin terdemineralisasi serta meningkatkan kekerasan mikro dentin terdemineralisasi.

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Background: Application of Mineral Trioxide Aggregate (MTA) as remineralization agent of affected dentin which holds a vital role in the preservation of tooth structure has been widely used in clinical practice, however it’s only capable of generating extrafibrillar remineralization resulting in the inability to produce dentin with mechanical properties resembling sound dentin. Carboxymethyl Chitosan (CMC) is a natural biomaterial developed as analogue of dentin non-collagenous proteins to inhibit the spontaneous precipitation of calcium-phosphate produced by the interaction of dentin with remineralization agent so that intrafibrillar remineralization can be accomplished.

Objective: To evaluate hydroxyapatite crystals characteristic and assess the microhardness of demineralized dentin after 14 days application of CMC-modified MTA.

Method: Remineralization was performed by the application of MTA, MTA-CMC 5%, and MTA-CMC 10% on demineralized dentin samples. During the remineralization process, root canals of tooth models were immersed in phosphate-buffered saline solution. Hydroxyapatite crystals’ characteristic was observed by X-ray Diffractometer, while dentin microhardness score was assessed by Vickers Hardness test.

Result: Formation of hydroxyapatite crystals was identified in MTA and MTA-CMC samples. Highest degree of crystallinity was found in MTA-CMC10% sample. Microhardness score of demineralized dentins in MTA-CMC 5% group and MTA-CMC 10% group was significantly higher than those in MTA group.

Conclusion: CMC-modified MTA application on demineralized dentin in 14 days was found effective in initiating hydroxyapatite formation with higher degree of crystallinity and increasing the microhardness of demineralized dentin."

"[ABSTRAKHroksiapatit merupakan jenis biomaterial sintetis yang mempunyai fasa yang paling stabil dibandingkan dengan senyawa kalsiun fosfat lainnya, selain itu hidroksiapatit memiliki tingkat kemiripan yang tinggi dengan tulang, sehingga hidroksiapatik banyak diaplikasikan sebagai bone graft sintetis. Tujuan dari penelitian ini adalah untuk mengetahui pengaruh waktu sintering terhadap kemurnian kristal hidroksiapatit yang dihasilkan. Hidroksiapatit dari prekursor kimia CaCO3 dan (NH4)2HPO4 disintesis dengan menggunakan metode hidrotermal pada temperatur 150oC dan 300oC. Hasil dari sintesis hidroksiapatik dikarakterisasi dengan menggunakan X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), dan Energy Dispersive Analysis X-Ray (EDX). Hasil karakterisasi XRD memperlihatkan intensitas tertinggi rata-rata berada pada sudut 2θ yaitu, 25.898o, 31.789o, 32.216o, 32.922o, 46.729o, dan 49.524o. Hasil dari SEM memperlihatkan morfologi dari sampel bebrbetuk nanoroot dan hasil dari EDX menunjukan rasio Ca/P sebesar 1.8.ABSTRACTHydroxyapatite is the most phase-stable syntetic biomaterial compared to another calcium phospate material. Hydroxyapatite also has high similarity with bone which make it has wide application as syntetic bone graft. Purpose of this research is to study the effect of sintering time towards hydroxyapatite crystal?s purity. Hydroxyapatite made from chemical precursor CaCO3 and (NH4)2HPO4 was synthesized using hydrothermal method on 150oC and 300oC. Synthesized hydroxyapatite was characterized using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive Analysis X-Ray (EDX). The result of characterization showed that highest average intensity on 2θ were: 25.898o, 31.789o, 32.216o, 32.922o, 46.729o, and 49.524o.;Hydroxyapatite is the most phase-stable syntetic biomaterial compared to another calcium phospate material. Hydroxyapatite also has high similarity with bone which make it has wide application as syntetic bone graft. Purpose of this research is to study the effect of sintering time towards hydroxyapatite crystal?s purity. Hydroxyapatite made from chemical precursor CaCO3 and (NH4)2HPO4 was synthesized using hydrothermal method on 150oC and 300oC. Synthesized hydroxyapatite was characterized using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive Analysis X-Ray (EDX). The result of characterization showed that highest average intensity on 2θ were: 25.898o, 31.789o, 32.216o, 32.922o, 46.729o, and 49.524o.;Hydroxyapatite is the most phase-stable syntetic biomaterial compared to another calcium phospate material. Hydroxyapatite also has high similarity with bone which make it has wide application as syntetic bone graft. Purpose of this research is to study the effect of sintering time towards hydroxyapatite crystal?s purity. Hydroxyapatite made from chemical precursor CaCO3 and (NH4)2HPO4 was synthesized using hydrothermal method on 150oC and 300oC. Synthesized hydroxyapatite was characterized using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive Analysis X-Ray (EDX). The result of characterization showed that highest average intensity on 2θ were: 25.898o, 31.789o, 32.216o, 32.922o, 46.729o, and 49.524o., Hydroxyapatite is the most phase-stable syntetic biomaterial compared to another calcium phospate material. Hydroxyapatite also has high similarity with bone which make it has wide application as syntetic bone graft. Purpose of this research is to study the effect of sintering time towards hydroxyapatite crystal’s purity. Hydroxyapatite made from chemical precursor CaCO3 and (NH4)2HPO4 was synthesized using hydrothermal method on 150oC and 300oC. Synthesized hydroxyapatite was characterized using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive Analysis X-Ray (EDX). The result of characterization showed that highest average intensity on 2θ were: 25.898o, 31.789o, 32.216o, 32.922o, 46.729o, and 49.524o.]"

"Fluor-hidroksiapatit (FHA) dapat digunakan sebagai biomaterial karena memiliki sifat biokompantibel. Ketika sebagian gugus hidroksil (OH-) dari hidroksiapatit digantikan oleh fluor (F-) maka akan terbentuk fluor-hidroksiapatit. Penelitian ini bertujuan untuk melihat pengaruh perubahan derajat keasaman (pH) dalam proses sintesis FHA menggunakan metode iradiasi gelombang mikro. Serbuk FHA disintesis dengan titrasi antara larutan kalsium hidroksida dengan ammonium fluorida dan diamonium hidrogen fosfat pada tingkat fluoridasi (x) 0,7 dan 1,3. Selama proses titrasi, penambahan larutan HCl 1 M dan NaOH 1 M dilakukan untuk membuat variasi nilai pH. Karakterisasi serbuk hasil sintesis dilakukan menggunakan analisis difraksi sinar-X (XRD), spektroskopi inframerah transformasi fourier (FTIR), mikroskop pemindai elektron (SEM), dan spektroskopi sinar-X energi dispersif (EDX). Hasil XRD dan FTIR menunjukkan bahwa serbuk dengan pH dibawah kondisi kontrol memiliki beberapa fase tambahan yang terbentuk seperti kloroapatit dan karbonat. Nilai kristalinitas memiliki perbedaan dari tiap serbuk di masing-masing pH, namun hanya pH kontrol yang memiliki kristalinitas seperti enamel gigi. Ukuran kristal rata-rata ditemukan sekitar 21-80 nm. Hasil SEM dan EDX menunjukkan perubahan morfologi dan rasio Ca/P yang terbentuk adalah 1,34. Hasil tersebut menunjukkan bahwa penambahan asam justru mengakibatkan terbentuknya fase baru yang mendominansi dan merubah beberapa parameter kristal, sehingga sintesis dalam keadaan pH yang dirubah tidak direkomendasikan.

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Fluoride-substituted hydroxyapatite (FHA) can be used for biomaterial application because it have biocompatible properties. FHA is formed by replacing the flour ion (F-) to the hydroxyl ion (OH-) from the hydroxyapatite. This work aims to see the influence of changes in the form of acidity (pH) at FHA synthesis process using microwave irradiation method. FHA nano-powder were synthesized using titration of calcium hydroxide solution with diamonium hydrogen phosphate and ammonium fluoride, which will vary the level of fluoride at FHA by 0,9 and 1,3. Subsequently HCl 1 M or NaOH 1 M to give variation of pH value. X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) spectroscopy analysis techniques were utilized in order to evaluate the characteristic of synthesized FHA nano-powder. The XRD dan FTIR result show that powder with pH under control conditions has several additional phases formed such as chloroapatite and carbonate. The value of crystallinity has the distinction of each powder in each pH, but only at pH control that has crystallinity values such as tooth enamel. Using a Scherrer formula, the average crystallite size was found around 21-80 nm. SEM and EDX characterization results show the Ca/P ratio formed is 1.34. The results showed that the addition of acid resulted in the formation of a new phase that dominates and revamp some crystal parameters, so the synthesis in these conditions is not recommended."

"Microstructure , crystal structure, and grain size observations on the Mg2 Al3 growth by mechanical alloying. Microstructure , crystal structure, and grain size observations on the growth of Mg2 Al3 phase by mechanical alloying have been performed. The Mg2 Al3 compound is prepared by milling process at various milling time of 10,20 and 30 h..."

"Latar Belakang: Osteoporosis adalah penyakit yang ditandai oleh BMD yang rendah dan mikroarsitektur jaringan tulang yang memburuk akibat kerapuhan tulang yang meningkat dan kerentanan terhadap patah tulang. Beberapa faktor lingkungan dan genetik dianggap dapat berkontribusi terhadap terjadinya penyakit osteoporosis. Salah satu gen yang dapat mempengaruhi proses resorpsi tulang adalah gen LRP5 Gen LRP5 telah terbukti memainkan peran penting dalam biologi tulang. LRP5 adalah protein transmembran dan berfungsi sebagai co-receptor untuk protein Wnt. LRP5 diekspresikan dalam osteoblast dan mempengaruhi pembentukan tulang dengan mengubah Wnt signaling.Tujuan: Penelitian ini bertujuan untuk melihat ada atau tidaknya polimorfisme dan perbedaan polimorfisme gen LRP5 Q89R pada wanita pascamenopause dengan osteoporosis.Metode: 100 bahan biologis tersimpan (50 sampel wanita pascamenopause dengan osteoporosis dan 50 sampel individu sehat) dianalisa menggunakan teknik PCR-RFLP dengan enzim retriksi AvaII, selanjutnya data diuji secara statistik menggunakan uji Chi-square.Hasil: Ditemukan banyak genotip QQ baik pada kelompok osteoporosis dan non-osteoporosis. Pada kelompok osteoporosis terdapat 93% genotip QQ dan 3% genotip QR dan tidak ditemukan genotip RR. Pada kelompok non-osteoporosis, terdapat 100% genotip QQ dan tidak ditemukan genotip QR dan RR.Kesimpulan: Tidak terdapat perbedaan bermakna pada distribusi polimorfisme gen LRP5 Q89R antara penderita osteoporosis dengan kelompok non-osteoporosis (p = 0.105).

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Background: Osteoporosis is a disease characterized by low bone mineral density (BMD) and deteriorating bone tissue microarchitecture due to increased bone fragility and susceptibility to fractures. Some environmental and genetic factors are considered to contribute to the occurrence of osteoporosis. One of the genes that can affect the bone resorption process is the LRP5 gene. The LRP5 gene has been shown to play an important role in bone biology. LRP5 is a transmembran protein and functions as a co-receptor for Wnt protein. LRP5 is expressed in osteoblasts and affects bone formation by changing Wnt signaling.Objective: This research aims to look for genetic polymorphism and differentiate the distribution LRP5 Q89R gene polymorphism in postmenopausal woman with osteoporosis.Methods: 100 stored biological samples (50 samples of postmenopausal woman with osteoporosis and 50 healthy control samples) were analyzed with PCR-RFLP technique using AvaII restriction enzyme, and subsequently assessed with statistical analysis using Chi-square test.Result: QQ genotype was found with the highest amount in both samples. The postmenopausal group has 94% of GG genotype, 6% of QR genotype, and no RR genotype was found. The healthy control group has 100% of GG genotype and no QR and RR genotype was found. Based on Fisher-Extract test, there is no significant association between LRP5 Q89R and postmenopausal osteoporosis (p value = 0.105).Conclusion: The genetic polymorphism of LRP5 Q89R in postmenopausal woman was found, but the polymorphism didnt have any association with osteoporosis in Indonesia populations."

"Telah diimplementasikan sistem elektronika berupa rangkaian osilator tipe colpitts untuk melihat karakteristik resonator kristal serta pengaruh perubahan nilai setiap komponen penyusun rangkaian osilator tipe colpitts pada perubahan frekuensi osilasi. data eksperimen yang didapatkan adalah pengaruh variasi tiap komponen osilator terhadap perubahan frekuensi dan tegangannya, serta pengaruh perubahan temperatur pada kristal terhadap frekuensi keluaran. Hasil dari karakteristik kristal yang dicoba dalam sistem ini bermanfaat sebagai sensor temperatur dengan jangkauan 10 - 50°C.

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An Electronic system has been implemented in the form of colpitts oscillator to see the characteristics of the crystal resonator and the effect of changes value of each component in colpitts oscillator circuit changed the frequency of oscillation. experimental data show the effect of variation of each component of the oscillator to change frequency and voltage, and also the effect of temperature changes on the crystal frequency output. the characteristics of the tested crystals obtained this system as a temperature sensor in the range of 10-50°C."