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.
Marketing studies are important to researchers and policy makers. The study of marketing margins and efficiency is important to understand the marketing problems that face parties of the marketing process. The aim of the research is to measure the efficiency margins and the most important marketing channels for marketing chicken meat in the province of Baghdad and to identify the most important marketing problems facing marketers of the commodity. The absolute marketing margins were (0, 1360, 1570, 1545) for the four channels respectively, while the price paid by the consumer was variable according to the marketing channel (3150, 3790, 3920, 4065) for the four channels respectively. T
Several studies have indicated an unprecedented increase in the number of Arab youth who watch music videos. It is also a custom in Arab countries to broadcast songs at their happy parties such as weddings, engagements and birthdays. We see that guests and party owners interact by dancing and singing with the songs, while the viewership rates of Arab music videos have reached millions on YouTube. The researcher decided to study the image of women through the lyrics of these songs, due to their importance in shaping the image of women in the minds of young people and shaping the (self-image) of young women. Twenty songs were selected from the most watched songs on YouTube for the year 2024, and it was found that the negative qualities of t
... Show MoreOrganizations adopt a number of procedures and instructions in their field of activities in order to aid their resources development and energies to serve their entrepreneurial orientations. This calls for preparing a range of mechanisms to mitigate the strictness and complexity of procedures. The ambiguity and severe complexity of procedures means acknowledging the loss in energy and this in turn impedes the hopes while in the same time weakens the enthusiasm in these organizations and an impedes the possibility to achieve continues innovation, thereby losing opportunities to the level of surrender to the risks and assuming them to be unconquered obstacles.
There
... Show Morethe energy that a radiation source emits as light (photons), electromagnetic waves, or particles is known as radiation. X-ray is one type of ionizing radiation that falls within the electromagnetic wave category of short wavelengths. Because of their short wavelength. X-ray is a type of ionizing radiation that is used in a constantly growing number of diagnostic procedures. X-ray diagnostic imaging has been employed in the medical field for more than a century(Hariyoto et al., 2020). Radiation has advantages for human health, but there is also a risk. the impacts of Radiation on Fertility it is an oligospermia, or a reduction in the number of sperm cells, which is already possible after radiation exposure of 0.15 mGy. It Leads to impede
... Show MoreThe research has tackled about an important transformation within the whole region of middle east, especially there were more challenges which revealed under the huge pivotal interests of global powers that ruled the new world order by United states of America ; being very affected over the international and regional relations than any situations appeared previously within political realities. So that, many of variables inside the international scene which happened during of this period of contradicting strategic policies by the process of reforming and restructuring of difficult equations that imposed by international and regional allies and blocs . This article had concentrated over various strategic and political studies which reflect
... Show MoreObjective: To assess two kinds of extraction (aqueous and methanolic) for Calendula officials using flowers, leaves
and stems and studying their antibacterial activity against five different bacteria.
Methodology: Calendula officials were selected to carry out this study. Flowers, leaves and stems were collected from
local markets in Baghdad then dried in shade for 7 days and grinded to fine powder. Aqueous hot extracts for 2hr. at
(100c˚) and alcoholic extracts for 48 hrs at (80c˚) were performed using flowers, leaves and stems then studied
antibacterial effect against five different bacterial genuses by using well diffusion technique.
Results: This study showed that hot aqueous extracts for 2hr. to all parts of Cale
ABSTRACT
This study aimed to choose top stocks through technical analysis tools specially the indicator called (ratio of William index), and test the ability of technical analysis tools in building a portfolio of shares efficient in comparison with the market portfolio. These one technical tools were used for building one portfolios in 21 companies on specific preview conditions and choose 10 companies for the period from (March 2015) to (June 2017). Applied results of the research showed that Portfolio yield for companies selected according to the ratio of William index indicator (0.0406) that
... Show MoreCastellated columns are structural members that are created by breaking a rolled column along the center-line by flame after that rejoining the equivalent halves by welding such that for better structural strength against axial loading, the total column depth is increased by around 50 percent. The implementation of these institutional members will also contribute to significant economies of material value. The main objectives of this study are to study the enhancement of the load-carrying capacity of castellated columns with encasement of the columns by Reactive Powder Concrete (RPC) and lacing reinforcement, and serviceability of the confined castellated columns. The Castellated columns with RPC and Lacing Reinforcement improve com
... Show MoreLanguages were not found in our life in a way utter coincidence , and it’s not flounce on people’s tongue randomly ‚ but laws are the controlling in languages‚ these laws could be lift to the same level of natural laws‚ phonetics form the main part in producing those languages‚ the Arabic language is one of those languages ‚ it’s largest dialects in Arabian Peninsula according to speakers number ‚ Arabic language link with these dialects through properties and phenomena sound and grammar‚ from this point my topic search is came Similar and different between Arabic and Arabian peninsula Accents balance linguistic–study voice of the Seine typically ) . and Similar and different of the ph
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