Background: 37% phosphoric acid (PA) is the traditional enamel etching technique prior to bracket adhesion, yet it has been implicated in numerous enamel injuries. The purpose of the current study was to create a calcium phosphate (CaP) etching paste in a simplified capsule formula that can underpin clinically adequate bracket bond strength without jeopardizing the integrity of enamel upon the debracketing procedure. Materials and Methods: micro-sized hydroxyapatite (HA) powder was mixed with 40% PA solution to prepare experimental acidic CaP paste. Sixty human premolars were assigned into two groups of 30 each. Enamel conditioning was accomplished using 37% PA-gel for control group and CaP paste for experimental group. Each group was further divided into two subgroups regarding the water storage (WS) period (24 h and 30 days). Shear bond strength (SBS) test conducted with examination of debonded surfaces for adhesive remnants and enamel damage using a digital microscope. Results: CaP paste produced significantly lower SBS values than PA (p < 0.01), yet sufficient for clinical use. PA etching caused often cracked enamel surfaces with excessive retention of adhesive remnants (mainly ARI scores 2 and 3). Contrarily, enamel treated with the experimental CaP paste exhibited smooth, unblemished surfaces mostly clean of adhesives residues (scores 0 and 1). Conclusion: a newly developed CaP paste in a capsule formula fosters clinically adequate bracket adhesion with a sustained bonding performance, allows a harmless bracket removal with minimal or no adhesive residues on debonded surfaces; thus, it can be introduced as a suitable alternative to PA.
Cloud computing (CC) is a fast-growing technology that offers computers, networking, and storage services that can be accessed and used over the internet. Cloud services save users money because they are pay-per-use, and they save time because they are on-demand and elastic, a unique aspect of cloud computing. However, several security issues must be addressed before users store data in the cloud. Because the user will have no direct control over the data that has been outsourced to the cloud, particularly personal and sensitive data (health, finance, military, etc.), and will not know where the data is stored, the user must ensure that the cloud stores and maintains the outsourced data appropriately. The study's primary goals are to mak
... Show MoreFinance is considered as an important and essential element when developing any housing policy which has a basic role creation of channels and effective means of saving money for individuals and institutions involved in the construction of housing units , and in particular that there is a deficit of residential dramatically in Iraq offset by a significant decline in the rates of construction housing and the accumulation of housing need in the coming years , the importance lies of the subject in creating mechanism for financing this sector and the impact of such a mechanism in solving the problem of the deficit number of housing units, through studying the experiences of some countries in the policies of housing finance to take advantage
... Show MoreAsthma is a chronic in?ammatory respiratory disease associated with the changes of asthmatic airway structural that result from interact remodeling and in?ammatory processes lead to obstruction of airway. Guggulsterone (GS) is a bioactive compound and plant steroid present in guggul gum of Commiphora wightii, which has anti-inflammatory and antioxidant activities. This study designed to investigate of anti-inflammatory activity of gugglsterone in improvement of asthma. Forty eight healthy albino male rats divided to six groups, Group I: Control group (distal water), Group II: Positive control group (distal water) with sensitization, Group III: Guggulsterone (25 mg/kg/day) with sens
... Show MoreBACKGROUND: Diffuse astrocytomas constitute the largest group of primary malignant human intracranial tumours. They are classified by the World Health Organization (WHO) into three histological malignancy grades: diffuse astrocytomas (grade II), anaplastic astrocytomas (grade III) and glioblastoma (grade IV) based on histopathological features such as cellular atypia, mitotic activity, necrosis and microvascular proliferation. Epidermal growth factor receptor (EGFR) is a 170-kDa transmembrane tyrosine kinase receptor expressed in a variety of normal and malignant cells regulating critical cellular processes. When activated, epidermal growth factor receptor (EGFR) triggers several signalling cascades leading to increased proliferatio
... Show Moreبعد ثورة تموز عام 1958في العراق, لم يكن يسمح للقطاع الخاص بأن تكون له استثمارات كبيرة في القطاعات الاقتصادية. وذلك بسبب الإيديولوجيات التي كانت تؤطر الفكر السياسي. حيث كان النهج الاشتراكي هو الغالب في إدارة الأنشطة الاقتصادية. إذ قامت الدولة بتأميم معظم الاستثمارات الخاصة الكبيرة ،لاس
... Show MoreDust storms are a common ecological occurrence in many world‘s countries, mainly in dry and semi-dry parts. Dust storms tremendously influence human health, the environment, the climate, and numerous social aspects. In this paper, spatial and temporal analysis, metrological triggers, and trajectory, dust exporting areas of a severe dust storm that occurred in Iraq on May 16, 2022, were investigated. The dust storm's backward trajectory was determined using HYSPLIT model, which is then compared with MODIS and Meteosat satellite images. The weather is then analyzed using the NCEP/NCAR Reanalysis model, and the approximate area of these sources was determined using Landsat 8 satellite image classification method. The results revealed
... Show MoreThe corcosion behoviour of Aluminum bronze in sodium chloride solution has been studied ^tentiostatically at five temperatures in the range 293-313K.The corrosion potential shifted to more negative values with increasing temperature. The corrosion current density increased with increasing temperature. Values of Tal'el slopes and the transfer coefficients indicated hydrogen evolution reaction to occur at the cathode and mainly the dissolution at the anode.Benzotriazole (BTA) had an inhibiting effect ??? the corrosion of the Al-bronze in deaerated NaCl solution at a concentration (1*10'?- IxlO‘1) mol dm'^ over the temperature range 293-313K. Values of the protection efficiency and kinetics parameters were obtained from the corrosion current
... Show MoreThe liver is one of the most prominent glands in the digestive system. It crosses vital organs with multiple functions, including the secretion of enzymes, digestion of fats, and secretion of bile. Through histological studies and those interested in them, the tissue structure of the liver is of interest to researchers, and the four samples of Guinea pig Cavia porcellus were taken in this study to know the histological structure and compare it with rodents in particular. and other animals in general. The results of the liver parenchyma were comparable to those of the studied mammals in periods of hepatocytes, Kupffer cells, and sinusoids surrounding the central vein, blood supply, and bile ducts. He did not record differences, eve
... Show MoreAbstract
Digital repositories are considered one of the integrated collaborative educational environments that help every researcher interested in developing the education and educational process. The learning resources provided by the repositories are suitable for every researcher, so digital information can be stored and exchanged by ensuring the participation and cooperation of researchers, teachers, and those who are interested, as well as curricula experts, teachers, and students, to exchange each other’s experiences in constantly updating that information as a reason for developing their performance in education. This reveals the importance of the role of educational digital institutions by providing and
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