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.
The aquatic crude extract of Silybum marianum dry grains prepared by melting them in distil water by the method of soak and shake. The effect of Silybum marianum crude extract studied in vitro on three tumor cell line the Hep-2, AMN-3 and RD for 24, 48 and 72 hours of exposure, and one cell line of normal cells REF for 72 hr exposure. The results showed that the prescence of toxic effect of the aquatic crude extract on the cell lines of Hep-2, AMN-3 and RD at 10 and 100 µg/ ml upto the higher concentrations when they exposed to the extract for 48 hr. as compared with the control treatment, and when the exposure period increased to 72 hr. the toxic effect started at low concentrations (5 and 10 µg/ ml) as compared with the control g
... Show MoreIn this study Isolated Pathogenic bacteria which causes Tonsillitis in Children with ages between 3-17 years. They are admitted to Central Children Hospital (Al-Karch) and Ebn-Albalady Hospital (Al-Rusafa). 200 cases were collected which include 120 Male and 80 Female. The result of the recent study shows that the isolation percentage was 40% from Male and 35% from Female. In this study Fifty six isolated were Identified, 20 were ?-hemolytic Streptococcus which was Streptococcus pyogenes, formed (36%) from all isolated.6 Pathogenic bacteria were ?- hemolytic Streptococcus which was Streptococcus pneumoniae formed (11%). The number of Moraxella catarrhalis bacteria was 12 formed (21%), the number of Haemophilus influenzae was 1
... Show MoreObjectives. This study was carried out to quantitatively evaluate and compare the sealing ability of Endoflas by using differentobturation techniques. Materials and Methods. After 42 extracted primary maxillary incisors and canines were decoronated, theircanals were instrumented with K files of size ranging from #15 to #50. In accordance with the obturation technique, the sampleswere divided into three experimental groups, namely, group I: endodontic pressure syringe, group II: modified disposable syringe,and group III: reamer technique, and two control groups. Dye extraction method was used for leakage evaluation. Data wereanalyzed using one-way ANOVA and Dunnett’s T3 post hoc tests. The level of significance was set at p<0:05. Results.
... Show MoreResearch aimed to explore the Application Effect of the Conflict Management Strategies by the managements to solve conflict between and inside the conflicted parties within (IGEC) to increase the productivity of the workers. To collect data, 110 questioners had been distributed among managers and heads of departments of all managerial levels, 102 answered questioners regained, 5 of them were disqualify for statistical analytic, only 97 were taking in consideration for statistical analysis presenting 93% of the retained number.
SPSS Program supported with a group of statistical tools, had been used for analysis purposes such as Kronbach Alpha test to assure the validity & stability of the t
... Show MoreThis research aims to identify the role and impact of illustrations in contemporary fashion design inspired by historical costumes. Historical fashion aesthetics are adapted to design drawings. The experimental method was followed and a sample of 31 students in the department of fashion and textile design, third level were selected. Each student carried out two original historical and contemporary design. The models were executed two times: one with the usage of the program and the other without program help. The tools that were used are the program, the scale, the pre-skill test, and the post-skill test. One of the most relevant results of the research is the possibility of using historical costumes to highlight creativity and innovatio
... Show MoreThis study aimed to investigate the effect of total suspended solids (TSS) on the performance of a continuously operated dual-chamber microbial fuel cell (MFC) proceeded by primary clarifier to treat actual potato chips processing wastewater. The system was also tested in the absence of the primary clarifier and the results demonstrated a significant effect of TSS on the polarization curve of the MFC which was obtained by operating the graphite anodic electrode against Ag/AgCl reference electrode. The maximum observed power and current densities were decreased form 102.42 mW/m2 and 447.26 mA/m2 to 80.16 mW/m2 and 299.10 mA/m2, respectively due to the adverse effect of TSS. Also
... Show MorePablo Neruda's artistic distinctiveness can be considered in two ideas or attitudes of romanticism. First, the imagination, which is the result of conduct and spirituality, and second, the individualism, which is a collection of mysterious mysteries from the texts of individuality based on philosophical sonnets. His collection of poems points out the ethereality and indescribability of life, employing the reality of life at the level of human perception in a symbolic language. In other words, Pablo Neruda recreates the meanings in poetry through the three ideas of reduction, interpretation, and analysis. "What is the essential connection between individualism and the symbolic language of Pablo Neruda's imagination and What are the reason
... Show MoreWalkability as one of the Planning Treatments to Face Epidemics in Cities
This work has been accomplished through a dense field work on the Sawa Lake. The aim of this work is to highlight on characteristics that are consistent with outstanding universal values to be a new Iraqi site belongs to the World Natural Heritage. This study sorted many unique characteristics might ensure that Sawa Lake as a world natural heritage sites. This study shows that the lake had met four natural criteria of the outstanding universal values: (1) the seventh criterion which states to contain superlative natural phenomena or areas of exceptional natural beauty and aesthetic importance. (2) The eighth criterion which stated to be outstanding example representing major stages of earth's history, including the rec
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