Background: Debonding orthodontic brackets and removal of residual bonding material from the enamel surface include critical steps that may cause enamel damage. The aim of the present study was to evaluate and compare the site of bond failure and enamel surface damage after debonding of three types of esthetic brackets (composite, ceramic, sapphire) bonded with light cure composite and resin-modified glass ionomer adhesive. Materials and methods: Seventy two maxillary premolars teeth were divided into three groups each group consisted of 24 teeth according to the type of brackets. Each group was subdivided into two subgroups (12 teeth for each) according to the bonding material that was used. After 7 days of bonding procedure, the brackets were debonded using specifically designed debonding device in which the brackets were debonded by a debonding pliers to simulate the actual clinical debonding procedure. Instron Universal testing was used to apply the debonding force on the debonding pliers which transferred to the bracket. The teeth and the brackets were examined with a 10X magnifying lens to evaluate the site of failure. After the removal of residual adhesive, stereomicroscope was used to evaluate enamel surface damage. Results: The most common type of bond failure was cohesive failure (Score II) in all esthetic brackets. While enamel cracks (scale I) were found to be the most type of enamel damage. Chi- square showed non-significant differences among different types of esthetic bracket bonded with same type of adhesive and between the same types of brackets (ceramic, sapphire) bonded with the two types of adhesive. On the other hand, there was significant difference between composite brackets subgroups bonded with the two adhesives. Conclusion: The bond failure mostly within the adhesive itself and higher enamel damage was resulted from mechanical debonding of these esthetic brackets.
Villages in most rural areas of the developing world, including Iraq, suffer from a deterioration in the urban structure in its various aspects, both in the lack of internal planning in terms of residential unit design which is not commensurate with the sustainable health life, in addition to the lack of infrastructure and community services networks As well as road networks linking them to neighboring urban centers, which was accompanied by the emergence of other problems, including the desire of the population to migrate to neighboring cities and the deterioration of economic activities due to lack of activation of economic development plans (Rural villages suffer from a lack of interest in urban development within the regional spatial
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Praise be to Allah and prayers and peace be upon our Prophet, Muhammad, his family and all of his companions,
This research addresses the issue of judge's preaching to the litigants and witnesses; it is a very significant issue since the judge cannot know the insides and facts, but it issues judgments based on the hearings. Since people are originally wrong-doing and ignorant, they, therefore, commit injustice, oppression, false adversarial, and false testimony. However, some people can possibly retreat and return to the right, after being inattentive or recalcitrant, by preaching. This fact led scholars to talk about the judge's preaching to litigant and witnesses and this research is conducted
... Show MoreThe aims of study is to detect the inhibitory effect of Saccharomyces boulardii and Lactobacillus acidophilus on Escherichia coli that has been isolated from recurrent urinary tract infection in women. The sensitivity of E.coli isolates to antibiotics had been studied and the most resistant E.coli isolate to antibiotics had been studied .The cup assay was used on nutrient agar and Muller-Hinton agar to detect the inhibitory activity for each S.boulardii yeast grown on YEGP media and L.acidophilus grown on MRS media in which the result showed a high inhibition activity for each of them .Also in this study the adhesion property of E.coli had been evaluated in the presence of S.boulardii at concentration of 1×109 and L.acidophilus at conc
... Show MoreThe recognition of the dynamic organizational capabilities in their actual and influential extent in the work environment achieves a set of positive data that can fall under the addition axes, particularly with regard to the organization's ability to manage human talents in them, so the researchers sought to identify the level of contribution of dynamic organizational capabilities in the management of human talents in terms of Keep them away in the research organization by indicating the level of relationship and impact between them. The presidency of Mosul University was chosen as a field for the current study, and data were collected by adopting the questionnaire form as the main tool for the study. The study used a deliberate
... Show MoreActual and effective organizational dynamic capabilities in the work environment contribute to a number of factors that contribute to the organization's ability to manage its human talents. Thus, the study sought to identify the level of contribution of organizational dynamic capabilities to human talent management based on their dimensions in the investigated organization by determining the level of relationship and impact between these variables. The presidency of Mosul University was chosen as a field for the current study, and data were collected by adopting the questionnaire form as the main tool for the study. The study used a deliberate sample of (42) administrative leaders in the investigated organization and adopte
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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
... Show MoreThe goal of this investigation is to prepare zinc oxide (ZnO) nano-thin films by pulsed laser deposition (PLD) technique through Q-switching double frequency Nd:YAG laser (532 nm) wavelength, pulse frequency 6 Hz, and 300 mJ energy under vacuum conditions (10-3 torr) at room temperature. (ZnO) nano-thin films were deposited on glass substrates with different thickness of 300, 600 and 900 nm. ZnO films, were then annealed in air at a temperature of 500 °C for one hour. The results were compared with the researchers' previous theoretical study. The XRD analysis of ZnO nano-thin films indicated a hexagonal multi-crystalline wurtzite structure with preferential growth lines (100), (002), (101) for ZnO nano-thin films with different thi
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