Background: Marginal adaptation is critical for long – term success of crown and bridge restoration. Computer aided design / computer aided manufacture (CAD/ CAM) system is gaining more importance in the fabrication of dental restoration. Objective: The aim of this study is to evaluate the effect of crystallization firing on the vertical marginal gap of IPS. emax CAD crowns which fabricated with two different CAD/CAM systems .Materials and Methods: Twenty IPS e.max CAD crowns were fabricated. We had two major groups (A, B) (10 crowns for each group) according to the CAD/CAM system being used: Group A: fabricated with Imes - Icore CAD/CAM system; Group B: fabricated with In Lab Sirona CAD/CAM system. Each group was subdivided into two subgroups pre-crystallized (Group A1, B1) and crystallized crowns (Group A2, B2). At four points on each aspect of the crown, marginal gaps were assessed on the master metal die by using digital microscope at a magnification of (110X) and image- J program. The measurement was done twice for each crown; before and after crystallization process.Results: The lowest mean of marginal gap before and after crystallization was (29.387±2.774μm) and (70.108±5.569μm) respectively for Group A (Imes - Icore system) and the highest mean value before and after crystallization was (51.728 ±3.774μm) and (84.071 ±4.567μm) respectively for Group B (Sirona system). Paired sample t-test result showed a statistically highly significant difference in marginal gap between all groups.Conclusions: The crystallization process increases the vertical marginal gap. Imes - Icore system showed the lower marginal gap than Sirona system. The two systems have an acceptable marginal gap
Films of pure polystyrene (ps) and doped by bromothymol blue material with percentages(4%) prepared by using casting technique in room temperature , the absorption and transmission spectra has been recorded in the wavelength rang (200-900)nm and calculated refractive index , reflectivity, real and imaginary parts of dielectric constant and extinction coefficient . this study has been done by recording the absorption and transmission spectra by using spectrophotometer .
This study sought to give a general picture of the organizations and formations of the ground forces of the Abbasid army in its first era, in preparation and armament and continuous development of the mechanisms to help maintain the moral and spiritual morale in the fighting.
Therefore, the caliphs' interest in building the army, organizing it, arming it, choosing competent leaders, and providing them with various weapons in terms of production and storage, as well as taking care of fortifying the cities and gaps in determination and determination, and embarked on construction and restoration, where amazing speed and acted according to the circumstances. During the first Abbasid era, there were significant developments in the military
A modified Leslie-Gower predator-prey model with a Beddington-DeAngelis functional response is proposed and studied. The purpose is to examine the effects of fear and quadratic fixed effort harvesting on the system's dynamic behavior. The model's qualitative properties, such as local equilibria stability, permanence, and global stability, are examined. The analysis of local bifurcation has been studied. It is discovered that the system experiences a saddle-node bifurcation at the survival equilibrium point whereas a transcritical bifurcation occurs at the boundary equilibrium point. Additionally established are the prerequisites for Hopf bifurcation existence. Finally, using MATLAB, a numerical investigation is conducted to verify the va
... Show MoreA modified Leslie-Gower predator-prey model with a Beddington-DeAngelis functional response is proposed and studied. The purpose is to examine the effects of fear and quadratic fixed effort harvesting on the system's dynamic behavior. The model's qualitative properties, such as local equilibria stability, permanence, and global stability, are examined. The analysis of local bifurcation has been studied. It is discovered that the system experiences a saddle-node bifurcation at the survival equilibrium point whereas a transcritical bifurcation occurs at the boundary equilibrium point. Additionally established are the prerequisites for Hopf bifurcation existence. Finally, using MATLAB, a numerical investigation is conducted to verify t
... Show MoreThis study examines the impact of adopting International Financial Reporting Standards (IFRS) on the value of economic units. Given the global push toward standardization of financial reporting to enhance financial statement transparency, comparability, and reliability, this research seeks to understand the implications of these standards for economic valuation within a region characterized by its unique economic and regulatory challenges. A questionnaire was distributed to 86 Iraqi academics specializing in economics, accounting, and finance to collect their views on the impact of adopting international financial reporting standards. Through careful statistical analysis, the study concluded that applying international financial reporting s
... Show MoreComputer systems and networks are being used in almost every aspect of our daily life; as a result the security threats to computers and networks have also increased significantly. Traditionally, password-based user authentication is widely used to authenticate legitimate user in the current system0T but0T this method has many loop holes such as password sharing, shoulder surfing, brute force attack, dictionary attack, guessing, phishing and many more. The aim of this paper is to enhance the password authentication method by presenting a keystroke dynamics with back propagation neural network as a transparent layer of user authentication. Keystroke Dynamics is one of the famous and inexpensive behavioral biometric technologies, which identi
... Show MoreInformation security is a crucial factor when communicating sensitive information between two parties. Steganography is one of the most techniques used for this purpose. This paper aims to enhance the capacity and robustness of hiding information by compressing image data to a small size while maintaining high quality so that the secret information remains invisible and only the sender and recipient can recognize the transmission. Three techniques are employed to conceal color and gray images, the Wavelet Color Process Technique (WCPT), Wavelet Gray Process Technique (WGPT), and Hybrid Gray Process Technique (HGPT). A comparison between the first and second techniques according to quality metrics, Root-Mean-Square Error (RMSE), Compression-
... Show MoreThe research aims to verify that there is an influence between innovative marketing and the organization's reputation by brand mediation.
The research problem is that the Oil Marketing Company (SOMO) needs innovative, unconventional methods in marketing its products and improving its reputation by adopting a solid brand that adds value to the product.
The importance of the research: The importance of the research is highlighted as it deals with essential variables in business organizations that help increase customer loyalty by adopting a distinctive brand.
The research started from four main hypotheses to explore correlations and influence between researc
... Show MoreThe research aimed to determine the role of the agricultural extension in educating farmers about the legislation on the protection of the rural environment from pollution with chemical pesticides working in the Department of Agricultural Extension and Training and the Department of Agricultural Extension in the directorates of agriculture of Najaf and Qadisiyah, and to determine the role of the agricultural extension in the axis of farmers' use of the correct methods to protect the rural environment from pollution with chemical pesticides and the axis of the reasons that lead farmers to pollute the rural environment with chemical pesticides, and to achieve the objectives of this research prepared A questionnaire in the light of rev
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