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 inflammatory response is a crucial aspect of the tissues’ responses to deleterious inflammogens. This complex response involves leukocytes cells such as macrophages, neutrophils, and lymphocytes, also known as inflammatory cells. In response to the inflammatory process, these cells release specialized substances which include vasoactive amines and peptides, eicosanoids, proinflammatory cytokines, and acute-phase proteins, which mediate the inflammatory process by preventing further tissue damage and ultimately resulting in healing and restoration of tissue function. This review discusses the role of the inflammatory cells as well as their by-products in the mediation of inflammatory process. A brief insight into the role of natural an
... Show MoreThe doctrine of naturalism appeared in the sixties of the nineteenth century as a continuation of the realism tendency and an expression of feeling in historical and social conditions in the language known to societies in Western Europe. Naturalism is a literary doctrine with an artistic style derived from realism, but it carries with it a philosophical character. Thus, we can understand that naturalism is those external and social forces that impede human freedom, as opposed to the subconscious internal genetic forces that determine moral responsibility and human rationality, far from displaying aesthetic images, as it is closer to reality than imagination. Naturalism looks at several axes, the most important of which are mental and psycho
... Show MoreIn this work, thermodynamic efficiency of individual cell and stack of cells (two cells) has been computed by studying the variation of voltage produced during an operation time of 30 min as a result of the affected parameters:- stoichiometric feed ratio, flow field design on single cell and feed distribution on stack of cells. The experiments were carried out by using two cells, one with serpentine flow field and the other with spiral flow field. These cells were fed with hydrogen and oxygen at low volumetric flow rates from 1 to 2 ml/sec and stoichiometric ratios of fuel (H2) to oxidant (O2) as 1:2, 1:1 and 2:1 respectively. The results showed that
... Show MoreWith the growing number of Internet users, public and private arts activities have become increasingly popular. Adolescents have begun to establish aesthetic taste and new cultural values. This category is the most affected one by the published images and ideas especially in the social networking space and specifically the Facebook. It is the most important problem in their cultural composition. This research aims to detect the problems of social networking sites in nurturing the aesthetic taste of adolescents. The researcher used the analytical descriptive approach to obtain accurate information describing the current situation or depicting the social reality of adolescents. The research concluded that the public discourse in social med
... Show MoreThe aim of this study was spot light to the possibility of confection between hepatitis C&G viruses in Iraqi patients. The groups was studied included two groups as follow: 1- first group: its (Infected group) the patients of this group have Anti-HCV abs in their serum by using Indirect ELISA technique. 2- second group: its (Control group) the persons of this group have no Anti-HCV abs in their serum by using indirect ELISA technique. The result of this study was observed there was two patients from the first group have Anti-HGVabs in their serum with infection percent 2.70%, also the same result was found in the second group wich mean there was two persons have Anti-HGVabs in their serum with infection percent 8.33% .So when we comparin
... Show MoreBackground : Shoulder pain is a common problem that can pose difficult diagnostic and therapeutic challenges for the family physician It is the third most common musculoskeletal complaint in the general population, and account for 5% of all general practitioners musculoskeletal consults Objective: To determine the diagnostic performance of ultrasonography compared with the physical examination for detection of rotator cuff tears in painful shoulder syndrome. Method: Prospective study was done on seventy patients (48 male, 22 female), age ranged between 30-70 years (mean age 50 years), From February 2007 to July 2011, were subjected to comparative study in Al-Kindy teaching hospital with rotator cuff tears, including physical and ultrasonogr
... Show MorePraise be to God, who started his book with the praise of himself and prayers and peace be upon those who do not have a prophet after him and his family and companions and those who followed them with charity until the Day of Judgment. Either:
The research examines the meanings of the formulas of the increased verbs that were mentioned in Surat Al-Baqara, at the imam of the imams of the Islamic nation, namely, Al-Fakhri Al-Razi (d. 606 AH), may God Almighty have mercy on him. With the imams of Quranic scholars.
Objective(s): This study aims to evaluate the hardness of two commercially available cold cured acrylic resin material
(Vertex and PAN) when polymerized at different temperature in comparison to those polymerized by conventional
methods in air at 23C ± 5C.
Methodology: Eighty specimens, forty from cold cured acrylic (Vertex Type) and forty from cold cured acrylic (PAN
type) were prepared, flasking and packing procedure were done according to manufacturer direction and divided
according to processing as follow: 20 specimens (10 from Vertex type and 10 from PAN type) were processed in air for
two hours at 23C ± 5C under press (bench curing) as a control, and 60 specimens (30 from Vertex type and 30 from
PAN type) wer