Background: An accurate adaptation of the crown to the finish line is essential to minimize cement dissolution and to preserve periodontium in fixed partial denture cases. An accurate adaptation of crown is possible only when preparation details are captured adequately in the impression and transferred to cast. For these reasons, gingival displacement is necessary to capture subgingival preparation details.The aim of the present study is to measure in vivo the horizontal displacement of the gingival sulcus obtained by using three new cordless retraction materials (Magic Foam Cord®, Racegel and Astringent Retraction Paste) in comparison to medicated retraction cord. Materials and method: Thirty-two patients requiring porcelain fused to metal fixed partial denture for replacement of a missing maxillary posterior tooth (either one of thepremolars or the first molar). The patients are randomly divided into four groups of eight patients each according to the type of gingival retraction material used as follows: Group I: Medicated retraction cord (racemic epinephrine hydrochloride 0.3 ± 0.2 mg per inch of cord, #00), Group II: Magic Foam Cord® (expanding polyvinyl siloxane), Group III: Racegel (25% aluminum chloride gel) and Group IV: Astringent Retraction Paste (15% aluminum chloride paste). Three depth orientation grooves were prepared in the buccal and palatal surfaces of a maxillary premolar parallel with the long axis of the tooth, extending from the middle third to the gingival third with the level of the free gingiva using a flat-ended diamond fissure bur. Impression of the gingival sulcus was then made using monophase polyether impression material (Impregum™ Penta™ Soft, 3M ESPE, Germany), before and after gingival retraction with either of the aforementioned gingival retraction materials. The sulcus width, before and after gingival retraction was measured on the master cast (in µm), after its sectioning longitudinally bucco-palatally at the middle of the prepared grooves using a rotary diamond disc. The measurement carried out by using digital microscope (Dino-Lite)at a magnification of 230X. The horizontal gingival displacement (the distance from the end of each prepared groove to the crest of the gingiva) measured by subtracting the gingival sulcus width after retraction from that before retraction. Results: The findings of the present study showed that the highest mean of horizontal gingival displacement is recorded by Group IV (Astringent Retraction Paste) (250.7900 µm), whereas the lowest mean of horizontal gingival displacement is recorded by Group III (Racegel) (78.0988 µm). One-way ANOVA test showed statistically highly significant differences among groups (p< 0.01). Least Significant Difference test (LSD test) was also used to make multiple comparisons among groups and revealed a statistically highly significant difference between each two groups (p< 0.01). Conclusion: The two new gingival retraction pastes (Astringent Retraction Paste and Magic Foam Cord®) could be used for gingival retraction as alternatives to medicated retraction cord. They offer advantages of simplified placement technique and shorter application time with greater gingival retraction. Meanwhile, the use of Racegel alone is not recommended for gingival retraction since it provides the least gingival displacement.
In this paper, we introduce a DCT based steganographic method for gray scale images. The embedding approach is designed to reach efficient tradeoff among the three conflicting goals; maximizing the amount of hidden message, minimizing distortion between the cover image and stego-image,and maximizing the robustness of embedding. The main idea of the method is to create a safe embedding area in the middle and high frequency region of the DCT domain using a magnitude modulation technique. The magnitude modulation is applied using uniform quantization with magnitude Adder/Subtractor modules. The conducted test results indicated that the proposed method satisfy high capacity, high preservation of perceptual and statistical properties of the steg
... Show MoreThe Internet makes the world like a small village. It has the ability to make groups of the same ideas, thoughts, and identity close to each other by gathering them in one place. It is a way to communicate and share information and opinion; shaping and sharing of comprising individuals with common interests and the participation of individuals in a fruitful dialogue results in achieving a set of goals promote ideas and mobilizing people about issues and events of common interests.
To address the relationship of the internet via interactive communication and its ability to achieve social capital and discuss issues and various social events, the study sees that the problem of the study could be formulated as follows:
Consid
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The current study investigates the impact of virtual reality technology on industrial product design. The focus of this study is on the development of industrial products that utilize virtual reality technology, specifically examining the effects of this technology on the visual and design aspects of these products. The aim is to continuously improve the functionality of industrial products and enhance the user experience through virtual reality integration.
The first chapter of the study addresses the research problem, which centers around exploring the technological influence of virtual reality used in industrial products and understanding the functionalities it brings to the design process. Virtual reality technology facilitates th
This research included the study of different factors that may effect on gatifloxacin stability (anew quinolone synthetic antibacterial agent) in its aqueous solution in order to develop and optimize the best delivary of the drug to the eye (as eye drop) with maximum local concentration and minimum systemic absorption and toxicity.Different formulas of gatifloxacin solution for ophthalmic use (0.3%)w/v were prepared in citrate, acetate,citrate/phosphate and phosphate buffers,their tonicity adjusted with suitable quantity of sodium chloride.The effect of different factors that might affectthe stability of gatifloxacin in its prepared ophthalmic solution was studied and determined spectrophotometrically at 287 nm. The results showed t
... Show MoreAbstract : This research is a field study of international cities that hosted various events of which (Sports, Exhibitions, Scientific, Cultural) and other events, these positive impacts on the city driven by such hosts were identified. The research goal was to support hosting events to improve the hostess city and to draw future plans for further developments and to invest event’s hosting to strengthen the city’s value according to a strategic vision that looks for the future the most important conclusions are Entering events hosting is a part of urban development strategies and The most important recommendations are coordination between hosting event activities and its facilities with the infrastructure structure of the host city, its
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In this communication, introduce the split Mersenne and Mersenne-Lucas hybrid quaternions, also obtaining generating functions and Binet formulas for these hybrid quaternions and investigating some properties among them.
الخلاصة Bahraini Parliamentary Elections and their Impact on the Popular Uprising) Bahrain has a distinguished constitutional and parliamentary experience, which distinct it from the other Gulf Cooperation Council (GCC) countries. Its experience in this area is the second after the experience of Kuwait to establish a system of government based on modern constitutional principles. As the government presented the Constitution to the Constituent Assembly elected by people and approved in 09/06/1973. After that, it witnessed the birth of the first parliament elected by the people in 1973, but the experiment did not last long and the parliament dissolved by Prince, and didn’t determine the period of the return of the working with the
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This research test the relationship and the effect of an explanatory variable transparency in the organizational reputation responder variable by senior management in the departments of the Ministry of Housing and Construction centrally funded, As well as come out among other recommendations contribute to the achievement of organizational reputation of the organizations surveyed. Given the importance of the research topic for the public sector and the community and the environment in which they operate researcher designed questionnaire containing (30) items, and collected data from (92) respondents, representing the research community (eight establishments) exclusively and comprehensively, relying descriptive analytic
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The present study aims to identify the role of behavioral disorders (anxiety disorder, behavior disorder "behavior", confrontation and challenge disorder, aggressive behavior) in predicting bullying patterns (verbal, physical, electronic, school) in a sample of adolescents with autism spectrum disorder. For this purpose, the researcher developed scales to measure the behavioral disorders and the bullying patterns among adolescents with autism spectrum disorder. The researcher adopted the descriptive survey approach. The study sample consists of (80) adolescents with autism spectrum disorder with ages range from (15-19 years) and (45-53 years old) in association with israr association for people with special needs in the northern borders
... Show MoreThe environmental problems that have emerged recently as a result of pressure on the environment due to the increase in population size, especially in urban cities, where this increase was accompanied by the need for housing as well as the need for services and activities. This led to the establishment of many vertical residential buildings represented by residential complexes within the urban fabric of the city of Baghdad. As part of following the methodology of urban dictation policies in empty areas, and to accommodate the largest number of residents as a result of the multiplicity of floors and housing, these buildings must be subject to the standards and requirements of sustainability at the level of their spatial location and their
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