Background: The present study was conducted to evaluate the effects of different bleaching methods on the shear bond strength of orthodontic Sapphire brackets bonded to human premolars teeth using light cured composite resin and to determine the predominant site of bond failure. Materials and Methods: Thirty freshly extracted human premolars were selected and randomly divided into three groups (10 per group). These groups are: control (unbleached) group, hydrogen peroxide group (HP) 37.5% ; which is the in- office bleaching method group, carbamide peroxide group (CP) 16%; which is the at- home bleaching method group. After bleaching process was performed, all the teeth stored in distilled water in a sealed container at room temperature for 24 hours before bonding was initiated, then orthodontic brackets were bonded with a light cure composite resin, stored in distilled water at room temperature for another 24 hours before debonding then the brackets de-bonded and tested for shear bond strength using an Instron universal testing machine. For adhesive remnant index (ARI) the enamel surface and bracket base of each tooth were inspected under magnifying lens (20X) of a stereomicroscope. Results and Conclusions: Non-statistically significant differences of shear bond strengths were found between the control group and the bleached groups, the dental bleaching in both methods did not affect the SBS of Sapphire brackets. The mode of failure was mostly between the adhesive and the enamel and the bond failure between the bracket base and the adhesive were also observed. Keywords: Shear bond strength, tooth bleaching agents, orthodontic brackets, dental bonding.
This study is concerned with the recent changes that occurred in the last three years (2017-2019) in the marshes region in southern Iraq as a result of the changes in the global climate, the study included all the water bodies in the five governorates that are located in the southern regions of Iraq (Wasit, Maysan, Dhi-Qar, Qadisiyah and Basrah), which represent the marshes lands in Iraq. Scenes of the Landsat 8 satellite are used to create a mosaic to cover the five governorates within a time window with the slightest difference between the date of the scene capture, not to exceed 8 days. The results of calculating the changes in water areas were obtained using the classifier support vector machine, where high accuracy ratios were recorded
... Show MoreThe linguistic meaning of the verse in the Arabic dictionaries applies very much to the reality of rent and its effect. This is true of economic growth as a continuous increase in real per capita income in addition to the same thing. Therefore, development does not necessarily achieve a comprehensive and structural increase of the various economic sectors. As the rent came in the sense of a terrible land open Maim any fertilized. And the camel is a ma'aya and a ra'i: that is, it goes in the pasture and returns itself. This is similar to the extraction of oil after it is ready for investment and earn its revenue as soon as it exists or is extracted by external parties. If the rent is first linked to agriculture, especially the fertile lan
... Show MoreThe research in the variables of the political process and government stability tried to show the impact of the political process on political stability first, and then on government stability second, given that the political process that was established in 2005 was aimed at achieving legitimacy, and its most prominent tools are elections, leading to achieving political stability, including government stability. The issue of governmental stability is one of the important issues in Iraq, but it has not been achieved, as a result of several factors, including problems in political action, as the political process has not succeeded in leading Iraq to stability.
Following the political development in Iraq Since 7112 exposed kind of political traditions about how to manage the conflicts that have different Iraqi powers .That what was clear since the formation of permanent government since in 7112 .
The case of conflict between political powers in administrating Iraq state and the withdrawal of American Forcesintroduces questions:
0-Is it possible that that the beginning of Iraq state building shall ease this conflict and peacemaking in the post-conflict period?
7- To what extent the Iraqi powerswas to manage their disputes in non-military like elections which was held in 7112?
2- What is the range of the extent of the political operation after the American withdrawal?
The important
In vitro antifungal susceptibility test of itraconazole was carried out against 38 isolates from nails, skin, oral cavity, vagina and wounds, This study was done in Ramadi Teaching Hospital in period from January to August 2010. According to the National Committee for Clinical Laboratory Standard (NCCLS ) M 27- A by using the broth dilution method. Inoculum size was 1-5X103 CFU/ ml, while final concentrations of itraconazole ranged from 0.025 – 6.4 μg / ml by using RPMI – 1640 broth media and the fungus was incubated at 35 oC. No resistant stain was recorded. MIC ranged from 0.05 – 6.4 μg / ml and the Mean ± SEM was 0.89 ± 0.28. MIC for nail isolates was 0.05 –
... Show MoreThe compound chalcon originally is extracted form some plant and herbs, the studies of the antiviral activity of this compound were done in two cell line cultures the L2OB and RD, the compound relatively non toxic to both cell lines of the concentration of 32?g/ml or less ,the compound have significantly anti poliovirus activity in both L2OB cell line and RD cell line, we find that the concentration of 0.03 ?g/ml or more inhibit the 100TCDID50 of the poliovirus .The therapeutic index(TI)used in this study to evaluate the drug activity ,( TI is the ratio of dose of drug which is just toxic to the cells to the does which is just inhibit the viral multiplication, if this index more than one the margin of safety of drug is according great ) .In
... Show MoreBackground:
Background: The aim of this study was to measure the radiopacity (RO) of modified microhybrid composite resins by adding 2 types of nanofillers (Zinc Oxide and Calcium Carbonate) in two concentrations 3% and 5% and comparing them to unmodified microhybrid composite resins and to nanofilled composite resin. Materials and Methods: Two types of composite resin were used (Microhybrid composite MH Quadrent anterior shine and Nanofilled composite resin Filtek Z350 XT), for each tested group five disk-shaped specimens (1-mm-thick and 15 mm diameter) were fabricated. The material samples were radiographed together with the aluminum step wedge. The density of the specimens was determined with a transmission densitometer and was expressed in term of
... Show MoreNeural stem cells (NSCs) are progenitor cells which have the ability to self‑renewal and potential for differentiating into neurons, oligodendrocytes, and astrocytes. The in vitro isolation, culturing, identification, cryopreservation were investigated to produce neural stem cells in culture as successful sources for further studies before using it for clinical trials. In this study, mouse bone marrow was the source of neural stem cells. The results of morphological study and immunocytochemistry of isolated cells showed that NSCs can be produced successfully and maintaining their self‑renewal and successfully forming neurosphere for multiple passages. The spheres preserved their morphology in culture and cryopreserved t
... Show MoreThe aim of this project was to study the in vitro effect of antineoplastic drugs (vincristine and vinblastine) on mice spermatozoa. Eighteen adult (age 8-9 weeks) male mice were divided into three groups equally. The animals in each group were slain by cervical dislocation, the testes were removed and two tails of epididymides isolated. Spermatozoa were obtained from the two tails of epididymides by mincing in 500 µl TCM-199.The first group non-treated (unadded) as a control group, second group added 10 µg/ml of vincristine to TCM-199 and the third group added 10 µg/ml of vinblastine to TCM-199. After 10 minutes from added of vincristine and vinblastin measured the following test: spermatozoa activity, percentage dead spermatozoa and mor
... Show More