PENGARUH PENGGUNAAN BAHAN PEMUTIH GIGI CARBAMIDE PEROXIDE 10% DAN CARBAMIDE PEROXIDE 15% TERHADAP KEKERASAN PERMUKAAN EMAIL

ABSTRAKNama: Elviyona YunindiaProgram Studi: Kedokteran Gigi Universitas Syiah KualaJudul: Pengaruh Penggunaan Bahan Pemutih Gigi Carbamide Peroxide 10% Dan Carbamide Peroxide 15% Terhadap Kekerasan Permukaan Email. Latar belakang. Produk bahan pemutih gigi saat ini sudah banyak digunakan di kedokteran gigi. Salah satu bahan pemutih gigi yang dapat digunakan di rumah dan dijual bebas dipasaran adalah carbamide peroxide 10% dan carbamide peroxide 15%. Carbamide peroxide merupakan bahan yang bersifat tidak stabil dan mudah terurai menjadi hidrogen peroksida dan urea. Kandungan dari hidrogen peroksida dapat menyebabkan perubahan struktur permukaan email. Salah satunya ditandai dengan penurunan kekerasan pada permukaan email. Tujuan. Tujuan penelitian ini adalah untuk mengetahui perbedaan antara aplikasi bahan pemutih carbamide peroxide 10% dengan carbamide peroxide 15% terhadap kekerasan email. Metode. Spesimen sebanyak 20 dibagi 2 kelompok aplikasi yaitu aplikasi dengan carbamide peroxide 10% dan aplikasi dengan carbamide peroxide 15% selama 6 jam dalam inkubator pada suhu 370C. Lalu masing-masing kelompok disimpan dalam larutan saliva buatan selama 24 jam dalam inkubator pada suhu 370C. Setiap spesimen dari masing-masing kelompok dilakukan uji kekerasan permukaan email sebelum dan sesudah aplikasi carbamide peroxide. Pengukuran kekerasan permukaan email dilakukan dengan menggunakan micro vicker hardness tester dengan berat beban 50 gr selama 15 detik. Hasil. Nilai pengukuran kekerasan email sebelum aplikasi carbamide peroxide 10% dan 15 % adalah 329,50 VHN dan 326,90 VHN, sedangkan nilai sesudah aplikasi carbamide peroxide 10% dan 15 % adalah 320,10 VHN dan 315,80 VHN. Kesimpulan. Uji Independent sample t-test tidak menunjukkan penurunan kekerasan yang bermakna antara carbamide peroxide 10% dan 15%. Kata kunci : Carbamide peroxide, waktu aplikasi, kekerasan email, micro vicker hardness teste

Evaluating the Whitening and Microstructural Effects of a Novel Whitening Strip on Porcelain and Composite Dental Materials.

AimsThe aim of this project was to evaluate the effects of 2 different whitening strips on color, microstructure and roughness of tea stained porcelain and composite surfaces.Methods54 porcelain and 72 composite chips served as samples for timed application of over-the-counter (OTC) test or control dental whitening strips. Chips were divided randomly into three groups of 18 porcelain and 24 composite chips each. Of these groups, 1 porcelain and 1 composite set served as controls. The remaining 2 groups were randomized to treatment with either Oral Essentials® Whitening Strips or Crest® 3D White Whitestrips™. Sample surface structure was examined by light microscopy, profilometry and Scanning Electron Microscopy (SEM). Additionally, a reflectance spectrophotometer was used to assess color changes in the porcelain and composite samples over 24 hours of whitening. Data points were analyzed at each time point using ANOVA.ResultsIn the light microscopy and SEM images, no discrete physical defects were observed in any of the samples at any time points. However, high-resolution SEM images showed an appearance of increased surface roughness in all composite samples. Using profilometry, significantly increased post-whitening roughness was documented in the composite samples exposed to the control bleaching strips. Composite samples underwent a significant and equivalent shift in color following exposure to Crest® 3D White Whitestrips™ and Oral Essentials® Whitening Strips.ConclusionsA novel commercial tooth whitening strip demonstrated a comparable beaching effect to a widely used OTC whitening strip. Neither whitening strip caused physical defects in the sample surfaces. However, the control strip caused roughening of the composite samples whereas the test strip did not

Marked increase in PROP taste responsiveness following oral supplementation with selected salivary proteins or their related free amino acids

The genetic predisposition to taste 6-n-propylthiouracil (PROP) varies among individuals and is associated with salivary levels of Ps-1 and II-2 peptides, belonging to the basic proline-rich protein family (bPRP). We evaluated the role of these proteins and free amino acids that selectively interact with the PROP molecule, in modulating bitter taste responsiveness. Subjects were classified by their PROP taster status based on ratings of perceived taste intensity for PROP and NaCl solutions. Quantitative and qualitative determinations of Ps-1 and II-2 proteins in unstimulated saliva were performed by HPLC-ESI-MS analysis. Subjects rated PROP bitterness after supplementation with Ps-1 and II-2, and two amino acids (L-Arg and L-Lys) whose interaction with PROP was demonstrated by (1)H-NMR spectroscopy. ANOVA showed that salivary levels of II-2 and Ps-1 proteins were higher in unstimulated saliva of PROP super-tasters and medium tasters than in non-tasters. Supplementation of Ps-1 protein in individuals lacking it in saliva enhanced their PROP bitter taste responsiveness, and this effect was specific to the non-taster group.(1)H-NMR results showed that the interaction between PROP and L-Arg is stronger than that involving L-Lys, and taste experiments confirmed that oral supplementation with these two amino acids increased PROP bitterness intensity, more for L-Arg than for L-Lys. These data suggest that Ps-1 protein facilitates PROP bitter taste perception and identifies a role for free L-Arg and L-Lys in PROP tasting

Effects of ambient temperature and injection pressure on biodiesel ignition delay

Biodiesels are promoted as alternative fuels due to their potential to reduce dependency on fossil fuels. The main problem in diesel combustion chamber design is to understand the importance of interaction phenomenon between fuel spray and surrounding gas prior to ignition. Rapid compression machine (RCM) is widely used to acquire experimental insights into fuel autoignition at conditions relevant to the current and future combustion technologies. An experimental study of the measurement of ignition delay characteristics of diesel and blended biodiesel fuels in the RCM was carried out. The objective of this study is to investigate the effects of various ambient temperature, Ti and injection pressure, Pinj on ignition delay with different fuels used. This present study used the ignition delay of 5vol%, 10vol%, and 15vol% blending of palm oil methyl ester with a standard diesel as fuels in diesel engines called as B5, B10, and B15. The diesel fuel was blended with the biodiesel fuels at different fuel mixture blends. The injection pressure chosen was from 80 MPa to 140 MPa while an ambient temperature of RCM varied from 750 K to 950 K. The results showed that for all tested fuels, the reduction in ignition delay increased with the increase in ambient temperature and injection pressure. The palm oil biodiesel had higher density, viscosity, and cetane number, facilitated the shortest ignition delay when compared to the diesel fuel under all ambient temperatures and injection pressures. The fuel oxygen content in the biodiesel fuel also played a greater role in decreasing the ignition dela

Research of the process of obtaining carbamide phosphate

В статье рассмотрено получение азотно-фосфорного удобрения (фосфат карбамида) из карбамида и ортофосфорных кислот различной чистоты. Определены особенности растворения карбамида в ортофосфорной кислоте и кристаллизации фосфата карбамида в зависимости от концентрации ортофосфорной кислоты. Представлены рентгенограммы и дериватограммы полученных образцов фосфата карбамида (CO(NH₂)₂∙H₃PO₄). Показана зависимость изменения массы фосфата карбамида от времени взаимодействия и температуры процесса. Установлена оптимальная концентрация ортофосфорной кислоты для получения фосфата карбамида.The purpose of the article is to study the process of obtaining fertilizer in the systems urea-orthophosphoric acid-water. A typical example of such a fertilizer can be carbamide phosphate. In connection with this, it is of interest to obtain urea phosphates depending on the concentration of orthophosphoric acid. The following methods were used in the studies: X-ray phase analysis, visual-polythermal, differential-thermal analysis. As a result of the studies, the characteristics of carbamide dissolution in orthophosphoric acid and the crystallization of carbamide phosphate were determined depending on the concentration of orthophosphoric acid, X-ray diffraction patterns and thermograms of carbamide phosphates were obtained. The general procedure for the preparation of urea phosphate from orthophosphoric acid and urea. As a result, a solid fraction was obtained - crystals of carbamide phosphate. X-ray analysis showed that the composition of carbamide phosphate obtained from orthophosphoric acid (analytically pure) is identical to the composition of carbamide phosphate obtained from orthophosphoric acid (commercially pure). Differential thermal analysis (thermographic studies) showed that the endothermic effect for orthophosphoric acid (analytically pure) and orthophosphoric acid (commercially pure), respectively, at 110 °C and 115.1 °C, characterizes the fusion of carbamide phosphate followed by the formation of ammonium pyro- and metaphosphate. It was established that irrespective of the purity of the phosphoric acid used, the product of the interaction is carbamide phosphate. The optimal concentration of phosphoric acid (CH₃PO₄) for the production of carbamide phosphate is 80 %. Since at this concentration the loss of moisture is faster than with CH3PO4 = 86%, and the yield of the product is almost the same, while at phosphoric acid concentrations of 75 and 60 %, the yield of the product is much lower

Developing porous ceramics on the base of zirconia oxide with thin and permeable pores by crystallization of organic additive method

In this paper porous ceramics on the base of ZrO[2] nanopowders and micropowders has been developed by freeze-casting method. A zirconia/carbamide slurry was frozen in mold and dehydrated in CaCl[2] at room temperature. This simple process enabled the formation of porous ceramics with highly aligned pores as a replica of the carbamide crystals. The samples showed higher porosity of 47.9%. In addition, these materials could be used as membrane for air cleaning

Effect of fertilizer carbamide on proteolytic enzymes of fish Labeo rohita

Specific activities of acid, alkaline and neutral proteases in liver, muscle, brain, and gill of fish exposed to 50 ppm ambient carbamide for 15, 30 and 60 days and in control were estimated. It was observed that carbamide even at low concentration of 50 ppm inhibited proteolysis and favoured protein synthesis

Effect of bleaching agents on enamel surface of bovine teeth: a SEM study

This study aimed to evaluate changes in the enamel surface of bovine teeth after whitening with exogenous bleaching agents: 10% carbamide peroxide (group 1), 16% carbamide peroxide (group 2) and 35% hydrogen peroxide activated by a light-emitting diode (LED) (group 3). The evaluations were performed by scanning electron microscopy (SEM). Ninety bovine teeth were divided into five groups (n = 18). The bleaching agents 10% and 16% carbamide peroxide were applied for eight hours a day for 14 consecutive days. The third agent, LED-activated 35% hydrogen peroxide, was used four times at seven-day intervals. Each of the four time points consisted of three applications of 10 minutes each. A 37% phosphoric acid solution and artificial saliva were used as positive and negative controls, respectively. The evaluations by SEM showed changes in the enamel surfaces of the specimens. Based on the Mann-Whitney statistical test, the data showed significant differences (p0.05) was observed between groups 1 and 3. Based on these results, it can be concluded that bleaching agents can cause changes in the structure of tooth enamel and that these changes are related to the concentration and the duration of contact with the tooth surface