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.
Summary The objective of the research is to learn the design of a learning educational learning according to the theory of Ausubel in the acquisition of geographical concepts among the students of the fourth primary in the field of geography and the development of their habits of mind. To achieve this, the researcher relied on the two hypotheses the researcher used the design of equal groups the first experimental group was studied according to the design educational educational learning according to the theory and the other is an officer according to the traditional method. The research community consists of fourth grade pupils in primary school day for girls in the Directorate of Education Baghdad, Al-Rusafa, the third academic year 20
... Show MoreCataract, which is the opacity inside clear ocular lens of eye, result in the scattering of visible light as it passes via the lens and consequently deterioration in optical image. The aim of the present study was to investigate whether safranal, an active constituent of Crocus sativus L. stigmas, has a protective effect on the cataract in the rat's pups. The animals were randomly divided into five groups, each of which consisted of 7 rat pups. Group I served as normal control (vehicle administration). For testing cataract induction, animals of Groups II, III, and IV were administered a single subcutaneous injection of sodium selenite on postpartum day 12. After sodium selenite intoxicatio
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Westernization is a term not familiar to our scholars at the beginning of the emergence of translation from Western literature, sciences and arts in its detailed form now.
Westernization was not an issue that those Greeks, Persians, Romans, Indians and others worked on translating those sciences and cultures. Rather, it was a process of transferring a new philosophy and logic that had not been previously seen by the Arabs, so they were affected by it in a strange way, to the point of fascination by some of them. For this reason, this research came to clarify these issues and address them within the scientific methodology.
A total of 60 species of aquatic oligochaetes were identified in different sites within Tigris-Euphrates basin / Iraq, including River Tigris, River Euphrates, Southern marshes ( Al-Haweiza , Al-Hammar and Al-Chebaiesh ) , Shutt Al-Germa, and Shatt Al-Arab. In River Euphrates 39 species were identified, 40 species from River Tigris and 32 species from Shatt-Al-Arab and southern marshes.The identified species were classified as four species of Family Aeolosomatidae, 54 species of Naididae ( 31 Naidinae , 8 Pristininae and 15 Tubificid worms), one species of each of Lumbriculidae ( Lumbriculus variegates ) and Lumbricidae ( Eiseiella tetraedra). Among Aeolosomatidae , Aelosoma aquaternarium, A. Liedyi, A. variegatum and A. hemprichi
... Show MoreThe present study was conducted to evaluate the effect of different inhibitors on the corrosion rate of aluminum in 50% (v/v) ethylene glycol solution at 80°C and pH 8.0 in which the electrochemical technique of linear sweep voltammetry was employed to characterize each inhibitor function and to calculate the corrosion rate from Tafel plots generated by a computer assisted potentiostat.
It is found that both sodium dichromate and borax reduces the corrosion rate by polarizing the anodic polarization curve while sodium phosphate, potassium phosphate, and sodium benzoate reduces the corrosion rate by polarizing both the anodic and cathodic polarization curve.
When inhibitor concentration increases from I g/l up
... Show MoreThis study has sought to explore the Yemeni online news websites’ treatment of the tropical storm “Luban” which hit the coasts of al-Mahra governorate, and other parts of the Yemeni Eastern and Southern governorates in October 2018. The study also examined how the Yemeni news websites covered the disaster on the basis of the problematic situation model. The study’s findings revealed a form of logical balance in distributing the coverage of the disaster in its different phases. The coverage was a bit more focused on the disaster phase than the pre- and post-disaster phases. Additionally, the websites paid more attention to precautionary measures and the disaster’s humanitarian and material losses. The findings reveal that the ne
... Show MoreThis work was conducted to study the recovery of catalyst and desirable components from tar formed in phenol production unit and more particularly relates to such a method whereby better recovery of copper salts, phenol, benzoic acid and benzoate salts from tar by aqueous acid solution was accomplished.
The effect of solvent type, solvent concentration (5, 10, 15, 20, 25 and 30 wt%), agitation speed (100, 200, 300 and 400 rpm), agitation time (5, 10, 15, 20 and 25 min), temperature (90, 100, 110, 120, 130 and 140 oC) , phase ratio (1/1, 2/1, 3/1, 4/1 and 5/1) and number of extraction (1, 2, 3, 4, and 5) were examined in order to increase the catalyst and desirable components extraction.
Four types of solvent were used; hydrochloric
The study of this topic is not to underestimate the previous studies but to the great importance of the Sunnis of the report. The reasoning of the Hadiths of the report is a kind of invisibility in that the significance is not a phenomenon such as the emergence of reasoning in the words of words and deeds. With the introduction of all types of Sunnah and protest, there is no difference between them, and that the Sunnis argument like other Sunnah. What we will see in the research.
Glorify and Praise be to God, and prayers and peace be upon the Messenger of God, his family, companions, and those who are loyal to him.
The subject derives its significance from two important sources , the first one lies in the Sunnah of the Prophet, while the other is the family source , which enrich this subject with great importance.
As for the objective of the topic, it shows to the reader the prophetic bases that mitigate and ease the burden of the husband in a way that secures the marital happiness, so that the Muslim woman takes it as a path for her in life and a slogan that illuminates the darkness of the path and makes her to overcom
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