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Hasil Pencarian

Ditemukan 3 dokumen yang sesuai dengan query
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Parenteral monofluorophosphate (MFP) is a more potent inducer of enamel fluorotic defects in neonatal hamster molars than sodium fluoride
"Supra-optimal intake of sodium fluoride (NaF) during early childhood results in formation of irreversible enamel deffects. Monofluorophosphate (MFP) and NaF was considered as less toxic than NaF but equally cariostatic. We compared the potency of MFP and NaF to induce preeruptive sub-ameloblastic cysts and post-eruptive white spots and pits in developing hamster enamel. Hamster pups were injected subcutaneously with either NaF or MFP in equimolar doses of either 9 mg or 18 mg F/kg body weight. At 9 mg F/kg, MFP induced more but smaller sub-ameloblastic cyts with a collective cyst volume twice as large as that induced by NaF. Eight days after F injection, all F-injection groups had formed 4-6 white spots per molar, with an additional 2 pits per molar in the low MFP group. Twenty-eight days after injection, most white spots had turned into pits (5-6 per molar) and only the high MFP group still contained 2 white spots per molar. We conclude that parenterally applied MFP is more potent in inducing enamel defects than NaF. Most white spots formed turn into pits by functional use of the dentition. The higher potency of parerental MFP may be associated with sustained elevated F levels in the enamel organ by enzymatic hydrolysis of MFP by alkaline phosphatase activity."
Lengkap +
ODO 102:2 (2014)
Artikel Jurnal  Universitas Indonesia Library
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Dwi Putra Ramadhan
Perbandingan Peningkatan Kekerasan Email Setelah Pengaplikasian Bahan Remineralisasi Propolis Fluorida dan Natrium Fluorida = Comparison of The Increase In Enamel Hardness After The Application of Propolis Flouride and Sodium Fluoride Remineralization Materials
"ABSTRAK
Latar belakang: Karies gigi merupakan penyakit multifaktor yang disebabkan oleh interaksi komplek biofilm dengan sumber karbohidrat yang menempel di permukaan gigi. Salah satu proses yang terjadi pada email gigi untuk terbentuknya karies adalah proses demineralisasi gigi yang terjadi secara dominan dibandingkan dengan proses remineralisasi. Upaya yang dapat dilakukan untuk mencegah karies adalah dengan pengaplikasian bahan remineralisasi seperti propolis fluorida dan natrium fluorida. Penggunaan bahan remineralisasi ini dapat meningkatkan kekerasan email. Tujuan: Membandingkan peningkatan kekerasan email setelah pengaplikasian bahan remineralisasi propolis fluorida dan natrium fluorida. Metode: 32 sampel gigi premolar dibagi menjadi kelompok propolis fluorida dan natrium fluorida. Seluruh spesimen ditanam di dalam pipa paralon dan dilakukan penghalusan dan pemolesan. Seluruh spesimen dilakukan tes kekerasan awal. Kemudian dilakukan demineralisasi dengan menggunakan Buavita® (pH 3,85). Setelah itu spesimen diukur kekerasannya, kemudian diaplikasikan propolis fluorida dan natrium fluorida dan direndam dalam saliva buatan selama 3 hari. Setelah itu dilakukan pengukuran kekerasan akhir dan dibandingkan secara statistik. Hasil: Natrium Fluorida lebih efektif dalam meningkatkan kekerasan email dibandingkan dengan Propolis Fluorida, dan juga terdapat perbedaan bermakna kekerasan gigi yang telah didemineralisasi dan kekerasan email gigi setelah diaplikasi bahan remineralisasi. Kesimpulan: Terdapat perbedaan bermakna antara peningkatan kekerasan email pada pengaplikasian propolis fluorida dan natrium fluorida.
ABSTRACT
Background: Dental caries is a multifactorial disease caused by the interaction of the biofilm complex with carbohydrate sources attached to the surface of the teeth. One process that occurs in tooth enamel for caries formation is the process of tooth demineralization that occurs predominantly compared to the remineralization process. Efforts that can be made to prevent caries are by applying remineralization materials such as propolis fluoride and sodium fluoride. The use of remineralization materials can increase the hardness of email. Objective: Compares increased enamel hardness after application of propolis fluoride and sodium fluoride remineralization materials. Methods: 32 premolar tooth samples were divided into propolis fluoride and sodium fluoride groups. All specimens were planted in paralon pipes and finalized and polished. All specimens were subjected to initial hardness tests. Then demineralization was done using Buavita® (pH 3.85). After that the specimens were measured hardness, then propolis fluoride and sodium fluoride were applied and soaked in artificial saliva for 3 days. After that, the final violence measurement and compared statistically. Results: Sodium Fluoride is more effective in increasing the hardness compared with Propolis Fluoride, and there were also significant differences in demineralized tooth enamel and tooth enamel hardness after remineralization.. Conclusion: There is a significant difference between increasing enamel hardness when applying propolis fluoride and sodium fluoride."
Lengkap +
Jakarta: Fakultas Kedokteran Gigi Universitas Indonesia, 2020
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UI - Skripsi Membership  Universitas Indonesia Library
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Naila Hanandhira
Efek rasio natrium nitrat-natrium fluorida sebagai degasser pada pengecoran aluminium tipe AC4B = Effect of sodium nitrate sodium fluoride ratio as degasser in aluminum AC4B casting product
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Pengaruh dari rasio natrrum nitrat—natrium fluorida sebagai degasser pada pengecoran aluminium tipe AC4B telah diteliti. Degasser merupakan salah satu metode yang digunakan dalam proses pengecoran untuk membantu menghilangkan gas-gas yang terdapat dilelehan logam, seperti gas hidrogen. Metode degassing yang umum untuk digunakan adalah degassing dengan memasukkan gas inert ke dalam lelehan logam, yaitu gas argon. Pada penelitian ini, digunakan metode degassing konvensional dalam bentuk tablet degasser berbasis natrium nitrat—natrium fluorida, dengan memvariasikan rasio perbandingan natrium nitrat—natrium fluorida. Variabel rasio yang digunakan adalah 0:0, 3:5, 1:3, 1:1, dan 3:1 untuk natrium nitrat berbanding dengan natrium fluorida. Material yang digunakan adalah aluminium tipe AC4B dengan tambahan scrap. Material tersebut dilebur pada suhu 720°C, kemudian tablet degasser dimasukkan ke dalam dapur peleburan dan ditahan selama 3 menit untuk memastikan seluruh tablet tersebut telah larut. Temperatur tinggi digunakan dalam peleburan material dikarenakan kelarutan gas hydrogen pada aluminium diatas 660°C sangatlah tinggi. Lelehan logam kemudian dituang ke dalam cetakan, denagn temperatur penuangan 690°C. Produk hasil pengecoran kemudian dilakukan pengujian mekanik seperti, pengujian Tarik, pengujian impak, pengujian keras, pengamatan mikrostruktur, dan perhitungan %porositas. Hasil pengujian menyatakan bahwa pada rasio 3:5 (degasser standar), diperoleh nilai porositas yang kecil (0,07%) dengan kekuatan mekanik yang lebih tinggi, yaitu kekuatan tarik 156,58 MPa, kekerasan 97 BHN, dan harga impak 0,20 J/mm2.

 

Effect of Sodium Nitrate—Sodium Fluoride ratio as degasser in Aluminum AC4B casting product has been investigated. Degassing is one of the methods used in the casting process to remove gases, such as hydrogen gases, in the molten metal. The most commonly used degassing method is by injecting an inert gas such as argon. In this experiment, a conventional degassing method with degasser-based sodium nitrate-sodium fluoride was used with changes in sodium nitrate to sodium fluoride ratio variables are 0:0, 3:5, 1:3, 1:1, and 3:1. The type of material used is AC4B material with additional scrap. The material melted first at 720°C, then the degasser was added into the furnace and held for 3 minutes. The high temperature was used to melt the material due to the solubility of hydrogen gases in liquid metal at above 660°C is high. The molten metal then poured into the mould at approximately 690°C. The casting process results are then prepared for mechanical testing, such as tensile test, impact test, and hardness test, microstructure, and %porosity testing. The results show that at the ratio of 3:5 (standard degasser), the porosity was lower (0,07%) and the mechanical strength was higher, such as tensile strength 156,58 MPa, hardness 97 BHN, and impact value 0,20 J/mm2.

 

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Lengkap +
Depok: Fakultas Teknik Universitas Indonesia, 2019
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UI - Skripsi Membership  Universitas Indonesia Library