Background: Adjustment of any premature occlusal contact of any zirconia restoration requires its polishing or glazing in order to restore the smoothness of the restoration. The objective of this in vitro study was to evaluate the effects of different polishing systems and glazing on the surface roughness of full-contour zirconia. Material and methods: Forty disks (diameter: 8 mm, thickness: 6.4 mm) were prepared from pre-sintered full-contoured zirconia block; they were colored and sintered in a high-temperature furnace at 1500˚C for 8 hours. The specimens were then leveled and finished using grinding and polishing machine and adjusted using diamond disk. The specimens were then randomly divided into four groups (n=10), group I involves samples that were polished using (karat diamond polishing set, Vita zahnfabrik, Germany), group II involves samples that were polished with (zirconia polishing kit, SMEdent, Shanghai, China), group III involves samples that were polished with (OptraFine® diamond polishing system, Ivoclar Vivadent, Germany), while group IV involves samples that were glazed using glazing medium (VITA Akzent Glaze AKZ 25, Vita zahnfabrik, Germany). Surface roughness values (Ra) (in µm) of all the specimens were recorded at each stage of surface treatment of zirconia disks (leveling and finishing, adjustment of the samples and polishing / glazing) using surface roughness tester. Statistical analysis was carried out using one-way ANOVA and LSD tests. Results: The results showed that the glazing group recorded the lowest surface roughness mean value, followed by (OptraFine® polishing system), then (zirconia polishing kit) and finally (karat polishing set) which showed the highest mean of surface roughness. For all groups, there was a statistically very high significant difference of (Ra) value before and after adjustment of the samples. Moreover, there was a statistically very high significant difference in (Ra) value when comparing the adjusted samples with the polished and glazed ones. Karat polishing set group showed a statistically highly significant difference with zirconia polishing kit group (P<0.01). Both, karat polishing set and zirconia polishing kit groups showed a statistically very highly significant difference (P<0.001) with (OptraFine® polishing system) and glazing groups. On the other hand, no statistically significant difference was found between glazing and (OptraFine® polishing system) groups (P>0.05). Conclusions: Adjusting full-contour zirconia with diamond bur or disk resulted in a significant increase in (Ra) that necessitates its polishing or glazing to restore the surface smoothness. Furthermore, both glazing and OptraFine® polishing system provided the best surface smoothness, so glazing can be substituted with chairside polishing using OptraFine® polishing system.
Objective: to assess the awareness and knowledge of our medical students regarding dose levels of imaging procedures and radiation safety issues, and to conclude how the curriculum of clinical radiology in the college medical program impacts such knowledge.
Subjects and methods: this is a cross-sectional study conducted among 150 medical students in Alkindy College of Medicine between January 2021 to July 2021, regardless of their age or gender. The study included six grades according to the year 2020-2021. A questionnaire consisting of 12 multiple-choice questions was conducted via an online survey using Google Forms. The questions were divided into two parts
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One of the most common public liver diseases over the world is fatty liver which contain alcoholic and non-alcoholic fatty liver. One-fourth among general population are impact Non-Alcoholic Fatty Liver Disease (NAFLD) in the worldwide.Retinol binding protein 4 (RBP4) is known as an adipokine, mainly synthesized and secreted from the liver and form adipose tissues. RBP4 acts as a transporter and specifically bound to retinol from liver to others tissues. Visfatin is an adipocytokine and mainly produced from visceral fat tissue, skeletal muscles as well as liver. Vitamin A absorbed, transported as retinyl esters to the liver then hydrolyzed to the retinol form and storage in hepatic stellate cells (HSCs) after reesterified with rigly
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The current study introduces a novel technique to handle electrochemical localized corrosion in certain limited regions rather than applying comprehensive cathodic protection (CP) treatment. An impressed current cathodic protection cell (ICCPC) was fabricated and firmly installed on the middle of a steel structure surface to deter localized corrosion in fixed or mobile steel structures. The designed ICCPC comprises three essential parts: an anode, a cathode, and an artificial electrolyte. The latter was developed to mimic the function of the natural electrolyte in CP. A proportional-integrated-derivative (PID) controller was designed to stabilize this potential below the ICCPC at a cathodic potential of −850 mV, which is crucial for prote
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Left bundle branch block (LBBB) is a common finding in electrocardiography, there are many causes of LBBB.
The aim of this study is to discuss the true prevalence of coronary artery disease (CAD) in patients with LBBB and associated risk factors in the form of hypertension and diabetes mellitus.
Patients with LBBB were admitted to the Iraqi heart center for cardiac disea
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Dapagliflozin is a novel sodium-glucose cotransporter type 2 inhibitor. This work aims to develop a new
validated sensitive RP-HPLC coupled with a mass detector method for the determination of dapagliflozin, its
alpha isomer, and starting material in the presence of dapagliflozin major degradation products and an internal
standard (empagliflozin). The separation was achieved on BDS Hypersil column (length of 250mm, internal
diameter of 4.6 mm and 5-μm particle size) at a temperature of 35℃. Water and acetonitrile were used as
mobile phase A and B by gradient mode at a flow rate of 1 mL/min. A wavelength of 224nm was selected to
perform detection using a photo diode array detector. The method met the
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BACKGROUND: Hepatocyte growth factor (HGF) is a proangiogenic factor that exerts different effects over stem cell survival growth, apoptosis, and adhesion. Its impact on leukemogenesis has been established by many studies. AIM: This study aimed to determine the effect of plasma HGF activity on acute myeloid leukemia (AML) patients at presentation and after remission. PATIENTS AND METHODS: This was a cross-sectional prospective study of 30 newly-diagnosed, adult, and AML patients. All patients received the 7+3 treatment protocol. Patients’ clinical data were taken at presentation, and patients were followed up for 6 months to evaluate the clinical status. Plasma HGF levels were estimated by ELISA based methods in the pa
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The H-Point Standard Addition Method (H-PSAM) has been applied for spectrophotometric simultaneous determination of Cimetidine and Erythromycin ethylsuccinate using Bromothymol Blue (BTB) as a chromogenic complexing agent in a buffer solution at pH 5.5.
Background: There are many congenital anomalies associated with cleft lip and/or palate. This research is to study the prevalence of congenitally missing teeth and supernumerary teeth in this population group. Materials and Method: One hundred eight cleft lip and/or palate Iraqi patients had participated in this study (57 male, 51 female), 3-12 years of age. 26 of them had orthopantomogram were within (6-12) years of age were inspected for congenitally missing teeth and supernumerary teeth. Patients whom age range 3-5 years were checked for the congenitally missing teeth by clinical examination with strongly insisting the teeth were not missed due to caries or trauma. Results: There were 19(73.076%) patients with 41 congenitally missing tee
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