Background: With the increased in the demands of adult orthodontics, the challenge of direct bonding to non-enamel surface (zirconium) had been increased. The present study was carried out to compare the shear bond strength of three different brackets (stainless steel, sapphire and composite) bonded to zirconium surface and study the mode of bond failure. Materials and methods: The sample was comprised of 30 models (8mm *6mm*1.5mm) of full contour zirconium veneers. They were divided into three groups according to the brackets type; all samples were treated first by sandblast with aluminum oxide particle 50 µm then coated by z-prime plus primer. A central incisor bracket of each group was bonded to the prepared zirconium surface with light cure adhesive resin (Transbond TM XT, 3M Unitek, USA). Shear bond strength was measured by using Tinius Olsen universal testing machine at crosshead speed of 0.5\min. After debonding, each bracket and zirconium surface were examined using magnifying lens and adhesive remnant index was recorded. The difference in shear bond strength between main groups was analyzed by using ANOVA at p≤0.05. Results: The results revealed high significant difference among all tested groups and the highest value was for sapphire brackets (7.49±1.45 Mpa) of all groups followed by stainless steel brackets (6.46±1.43Mpa) and composite brackets had the least value (4.35±0.72). Non-significant difference in the site of bond failure among all groups of brackets and zirconium-adhesive interface failure (score III) was the predominant. Conclusion: the new zirconium prime plus primer can be successfully used in bonding stainless steel and sapphire brackets to zirconium surface.
The marine collagens are biocompatible and biodegradable materials that are considered as a biomimetic approach for tissue regeneration. This study evaluated the effect of daily consumption of marine collagen supplement drink on enamel white spot lesions (WSLs), comparing the results against Regenerate system and Sylc air abrasion methods. Fifty human enamel slabs were allocated into five groups (n = 10 per group): non-treated (sound); non-treated (WSLs, 8% methylcellulose gel with 0.1 M lactic acid (pH 4.6) at 37 °C for 21 days); and three treated surfaces with marine collagen; Regenerate system; and Sylc air abrasion. The treatment lasted for 28 days followed by four weeks’ storage in artificial saliva (pH = 7.0, 37 °C). Evalu
... Show MoreAspartate aminotransferase was purified from urine and serum of patients with type 2 diabetes in a 2 steps procedure involving dialysis bag and sephadex G-25 gel filtration (column chromatography). The enzyme was purified 346.23 fold with 1467% yield and 3.46 fold with 142.85% yield in urine and serum of patients with type 2 diabetes respectively. The purified enzyme showed single peak. The results of this study revealed that AST activity of type 2 diabetes urine and serum increased significantly (p<0.001) compared with control group.
Under aerobic and anaerobic conditions, two laboratory-scale reactors were operated. Each reactor
was packed with 8.5 kg of shredded synthetic solid waste (less than 5 cm) that was prepared according to an
average composition of domestic solid waste in the city of Kirkuk. Using an air compressor, aerobic
conditions were created in the aerobic reactor. This study shows that the aerobic reactor was more efficient in
COD and BOD5 removal which were 97.88% and 91.25% while in case of anaerobic reactor, they were
66.53%and 19.11%, respectively.
Reconstruction in Iraq requires coherent legitimate frameworks that are able to detail obligations, rights and responsibilities of the parties participating in reconstruction projects, regardless their type or delivery system.
Conditions of Contract can be considered an important component of these frameworks. This paper investigates flexibility and appropriateness of the application of Iraqi conditions of contract in reconstruction projects. These conditions were compared to FIDIC Conditions. The objective wasn't comparing individual clauses, but rather exploring the principles and philosophy laying behind each conditions, and to what extent each conditions care about realizing equity between main contract parties. Validity of applic
Background: White spot lesions are esthetic problems caused by subsurface enamel demineralization that seen as white opacity. Aim of the study: This study aimed to evaluate and to compare the color change after the treatment of the white spot lesions with resin nϔtrton and micro abrasion. Materials and Methods: rtϔ white spot lesions were generated on 48 premolar teeth by the use of a demineralization solution. The teeth were randomly divided using the Diagnodent into three study groups (16 teeth for each group) depending on the depth of the induced lesions: outer enamel, inner enamel and outer dentine. Then each group was fatherly subdivided into two groups (8 teeth for each group) the ϔrst group was treated wit
... Show MoreEvaluation of the Antibacterial Efficacy of Electrolyzed Oxidizing Water as an Irrigant against Enterococcus faecalis (An In vitro Study), Noor A Khait*, Muna Saleem Kalaf
Background: Although mammography is a powerful screening tool in detection of early breast cancer, it is imperfect, particularly for women with dense breast, which have a higher risk to develop cancer and decrease the sensitivity of mammogram, Automated breast ultrasound is a recently introduced ultrasonography technique, developed with the purpose to standardize breast ultrasonography and overcome some limitations of handheld ultrasound, this study aims to evaluate the diagnostic efficacy of Automated breast ultrasound and compare it with handheld ultrasound in the detection and characterization of breast lesions in women with dense breasts. Objectives: To evaluate the diagnostic efficacy of Automated breast ultrasound and compare
... Show MoreBackground: Although mammography is a powerful screening tool in detection of early breast cancer, it is imperfect, particularly for women with dense breast, which have a higher risk to develop cancer and decrease the sensitivity of mammogram, Automated breast ultrasound is a recently introduced ultrasonography technique, developed with the purpose to standardize breast ultrasonography and overcome some limitations of handheld ultrasound, this study aims to evaluate the diagnostic efficacy of Automated breast ultrasound and compare it with handheld ultrasound in the detection and characterization of breast lesions in women with dense breasts.
Objectives:<
... Show MoreABSTRACT Background: This study aimed to study the effect of some acidic drinks (Vinegars and fresh Orange juice) and energy drinks (Red bull) on surface roughness of three types of bulkfill composite materials: Filtek posterior bulkfill (3M), Sonicfill (Kerr) and Filtek p60 (3M). Materials and Methods: Total number of 120 samples are prepared by using a mold of (12mm diameter and 3mm height), which were divided into three groups forty samples for each group: Group A: Filtek bulkfill posterior composite (3M), Group B: Sonicfill composite (Kerr), Group C: Filtek P60 (3 M) which then divided into four sub- groups (n=10) (1) samples were kept in distilled water as a control group (2) samples were immersed in Redbull (3) samples were immersed
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We report a method of converting non-conductive plastic surfaces into conductive by plating either copper electroless or copper electroplating -carbon black containing bending Agent onto Perspex plastics . Various approaches have been studied in order to comparing properties of the plated copper for two methods such as scanning electron microscopy (SEM),thickness, roughness, porosity, tensile Strength and elongation. The results show that the surface of electroplating was uniform, compact, and continuous and it had an obvious metallic sheen, while the surface of plated copper for electroless for it had many pores. Also observed that the coating was composed of small cells. Thes
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