Background: Reduction in bond strength when bonding was done immediately after intracoronal bleaching procedure has been recognized. The purpose of this study is to assess the effect of antioxidants (10% sodium ascorbate (SA), 0.1M thiourea and7% sodium bicarbonate (SB)) on reversing bonding strength of composite resin to bleached dentin. Materials and method: Sixty upper 1st premolar teeth, were selected, the crowns of the teeth were embedded in acrylic resin blocks exposing a flat dentin from the buccal surface, then divided into 6 groups (10 samples each). Bleaching for the experimental groups was performed using 35% hydrogen peroxide bleaching gel (pola–office).Group A (Negative control group; dentin samples immediately bonded with composite without bleaching)Group B (Positive control group; dentin samples bleached and immediately bonded with composite). Group C (Dentin samples bleached and stored for 14 days in DDW then bonded with composite). Group D (Dentin samples bleached and treated with 10% (SA) then immediately bonded with composite). Group E (Dentin samples bleached and treated with 0.1M thiourea then immediately bonded with composite). Group F (Dentin samples bleached and treated with 7% SB then immediately bonded with composite).The shear bond strength was determine using instron testing machine. Results: Bleaching the dentin with 35 % hydrogen peroxide gel for 24 minutes resulted in reduction in bond strength of the bleached teeth when bonding was performed immediately after bleaching. Delayed bonding of composite to the bleached dentin for 14 days will result in a highly significant increase in the shear bond strength. Conclusion: Treating the bleached dentin with 10% (SA) in water base showed a highly significant increase in the shear bond strength of the composite to dentin and reversing the bond strength value to the level of the unbleached dentin. Treating the bleached dentin with 0.1M thiourea significantly increased the shear bond strength of the composite to dentin.
After the success of the reforms Keynesian save the capitalist system from collapse and to apply the concepts of state intervention in economic activity in order to revive aggregate demand to achieve the purposes of macro-economic policies which draw their scope of economic (John Keynes) theory of effective demand, which created the new role of the state away from the classical concepts. Valley transmission role of the State of (State Guardian) to the process of state overlapping that increased and social functions have become responsible for raising the standard of living of classes with limited incomes, in particular, and the rest of the classes in general, through the expansion of the delivery of public servic
... Show MoreThe present study aimed to identify the availability of the National Council of Teachers of Mathematics (NCTM) standards in the content of mathematics textbooks at the basic education stage in the Sultanate of Oman. The study used the descriptive-analytical approach, adopting the method of content analysis through using a content analysis tool that included (43) indicators distributed on the four NCTM standards related to the field of geometry, after verifying their validity and reliability. The study population consisted of mathematics textbooks (first and second semesters) for ninth-grade students in the Sultanate of Oman in the academic year 2018/2019, while the sample consisted of Geometry units in the content of those books, which a
... Show MoreAbstract The results of isolation, morphological and microscopic diagnosis, Chromic Agar, Vitik technology and Bact Alert showed that the diagnosis of fungi isolated from blood samples of end-stage renal patients who did not undergo dialysis and those who underwent dialysis was 60 samples for each type. The total number of fungal isolates isolated from people who did not undergo dialysis was 26 pathogenic fungal isolates, with a percentage frequency of 43.33%. In this study, 4 genera of pathogenic fungi were identified: Candida spp, Rhodotorula spp, Cryptococcus spp. and Aspergillus spp. The number of Candida isolates reached 13 isolates, with a frequency of 50%. The results also showed that the diagnosed species from the genus Rhodotorula
... Show MoreThis study was based on the determination of aphid species that infested Chrysanthemum sp. (Asterales, Asteraceae) in the middle of Iraq; five aphid species belong to subfamily Aphidinae were recorded: Aphis fabae Scopoli, 1763, Aphis gossypii Glover, 1877, Coloradoa rufomaculata (Wilson, 1908), Macrosiphoniella sanborni (Gillette, 1908) and Myzus persicae (Sulzer, 1776). A. gossypii was the most dominant species throughout the study period while M. persicae is the lesser species.
A summary of the main taxonomic characters is presented here and a pictorial key which was designed to separate aphi
... Show MoreThe study aimed to investigate the employment of electronic supervision applications in developing the teaching performance of teachers in Oman. Based on the qualitative method and the study population consisted of all the teachers of the first cycle in the Governorate of Muscat. The study sample amounted to 24 female teachers. The interview was used as a tool for data collection. The study reached several results, including: There are difficulties in employing electronic supervision applications, which are weak network, density of curricula, lack of experience in applying technology, and the large number of tasks assigned to the teacher. These difficulties can also be overcome by strengthening the network, training teachers, reducing th
... Show MoreBackground: An injury to both the primary and permanent teeth and the supporting structures is one of the most common dental problems seen in children. Splinting is usually difficult or impossible to perform in the primary dentition (due to diminutive room size and lack of patient cooperation). Healing must, therefore, occur despite mobility at the fracture line, usually resulting in interposition of connective tissue. In some instances, infection will occur in the coronal pulp. The present study reported a case of trauma to the anterior primary teeth and alveolar bone in a four year old child. The trauma has caused fracture to the crowns and roots of the primary anterior teeth. The following case was managed in a procedure that may
... Show MoreTransformations of the actor when acting many characters are the product of joint work between the actor and the director through the instructions and the exercises that facilitate the reach for the desired goal.
The method or way has often been used which is Stanislavsky premises in his work with the actor in the role. The first section consists of two parts under the heading of the actor's work with himself. The two parts are preparing the actor in creative suffering (internal), and in coexistence and embodiment (outside). The second section is the book of the actor's work with the role. The current research aims at identifying the mechanism of the acting performance transformations among many characters of the same actor.
... Show MoreThe book of the summary in the control of the laws of Arabic is one of the most important books of Andalusian grammar, the resonance of which is clearly evident among the mother of the language books in the seventh century AH because of the character of the educational style easy and simplified service for anyone who wants the Nile Arabic grammar, that end through what is pursued in his book (Summary) on according to visual standards, as was Ibn Abi Al-Rabeea of first- type, and illustrated in which he addressed the analogies, and he followed the modalities expressed and its consequences relating to each attachment in which a (illness and reasoning factor) And what he said in the framework of each service for the study material in his ha
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