ABSTRACT Background: Color changes that are detectable to human eye can affect the esthetic appearance of ceramic veneers. The purpose of this study was to evaluate and compare the effect of artificial accelerated aging on the color of ceramic veneers cemented with different resin cements. Materials and Methods: Sixty discs were prepared with 0.5 mm thickness, 30 discs made from IPS e.max press (Ivoclar Vivadent) and 30 discs were made from VITA Enamic (VITA Zahnfabrik). The discs were cemented with three resin cements: Variolink Veneer MV 0 shade (Ivoclar Vivadent), Rely X veneer Translucent shade (3M ESPE) and NX3 Nexus Clear shade (Kerr Corporation) with 0.1 mm thickness. The spectrophotometer Easyshade Advance was used to measure the color parameters (Lightness, axis a* of chroma and axis b*of chroma) immediately after cementation, after 150 and 300 hours of aging. The specimens were subjected to artificial accelerated aging in Accelerated Weathering Tester. Color change greater than 3.3 was considered unacceptable. One-way ANOVA, paired t-tests and Bonferroni adjusted t-test were used for statistical analysis (p <0.05). Results: Artificial aging caused high significant color change in both ceramic types, but there were non-significant difference in color change among the three resin cements used. The color change was between1.997-14.8 after 150 hours and it was between 2.179-15.68 after 300 hours. The color change of e.max discs after aging were within acceptable limit<3.3 whereas Vita Enamic specimens had shown unacceptable color change >3.3 after aging. Conclusions: The majority of color change after aging related to veneering materials while resin cement have only slight effect on color change after aging. IPS e.max had shown an acceptable color change after aging, so it is suitable for fabrication of restorations in esthetic zone while Vita Enamic should not be used in esthetic zone since it has poor color stability according to the results of this study.
The business environment is witnessing great and rapid developments due to the economic and technological development that has caused damage to human beings, which requires the need to reduce this damage and work to protect the environment and participate in supporting the social aspects. This requires economic resources to be realized by the economic units. Economic development in preserving the environment that has caused damage and supporting the social aspects that preserve human rights, enhance their position and satisfy their needs in society. Global professional organizations, the United Nations and stakeholder representatives have been issuing the Global Reporting Initiative (GRI) to find guidelines for the preparation of
... Show MoreBackground: A great dental and biomedical interest had been paid to silver nanoparticles because of their antimicrobial activity. Objective: To evaluate the antimicrobial and cytotoxic activity of a newly developed Nano-silver fluoride that was synthesized from moringa oleifera leaf extract against S. mutants. Material and method: The green synthesis method was used to prepare Nano-silver fluoride from moringa oleifera leaf extract. The minimum inhibitory concentration and the minimum bactericidal concentration were evaluated using brain heart infusion plates, while the cytotoxicity was evaluated by the hemolytic activity. Results: Nano-silver fluoride had a bactericidal and bacteriostatic effect (MIC was 60 ppm a
... Show MoreIntroduction: Cardiovascular diseases are the main cause of death among type 2 diabetic patients. Higher levels of plasminogen activator urokinase receptor have been found to predict morbidity and mortality across acute and chronic diseases in the common populace. This study aims to explore the role of serum plasminogen activator urokinase receptor levels as a cardiometabolic risk factor among type 2 diabetic Iraqi patients. Methods: Seventy type 2 diabetic patients (40 male and 30 female) (mean age: 46.20±7.56 years) participated in this study; 35 patients were with cardiovascular disease and 35 were without cardiovascular disease; their ages range was 40-55 years. In addition, 30 individuals who apparently healthy were selected a
... Show MoreThe present study was performed on 80 female subjects between (30-60) years, who attended the Specialized Center for Endocrinology and Diabetes during the period from April to July; 2011. The subjects were divided into 3 groups : controls , non diabetic autoimmune thyroid patients , and non diabetic autoimmune thyroid patient with renal diseases as complication The results showed a significant increase in serum T 3 T4 levels in hyperthyroidism patients, and significant decrease in serum T3,T4 levels in hypothyroidism patients ,while a significant difference in serum TSH levels in hyperthyroidism and hypothyroidism patients when compared to control group The results show also a significant increase in serum antibodies to thyroid peroxidas
... Show MoreIn this research want to make analysis for some indicators and it's classifications that related with the teaching process and the scientific level for graduate studies in the university by using analysis of variance for ranked data for repeated measurements instead of the ordinary analysis of variance . We reach many conclusions for the
important classifications for each indicator that has affected on the teaching process. &nb
... Show MoreBackground: C-reactive protein (CRP) is an acute phase protein that its plasma levels increase after trauma or surgery so it is used as an indicator for the level of inflammation after surgery. The objective of this study is to investigate pre- and post-operative levels of CRP in three types of oral surgical interventions (Apicoectomy, Impaction, and Impacted teeth exposure). Materials and Methods: A total number of (48) healthy individuals aged (20-60) years who needed oral surgical intervention for either (removal of impacted third molars, exposure of an impacted canine, or Apicoectomy). A 4ml venous blood was obtained from each patient at two occasions (pre-operatively at the day of operation and post-operatively after 48 hours), then ce
... Show MoreThis study investigates the phonotactics of English obstruent clusters in the word-final position from a markedness theory perspective among Iraqi EFL College Students whose native language, Arabic, prefers only two-member word-final obstruent cluster as a maximum. The markedness of clusters is measured depending on Iraqi EFL College Students’ utilization of the simplification strategies. This study tries to answer whether or not word-final obstruent clusters are marked or unmarked for Iraqi EFL College Students, and whether or not the markedness of the obstruent cluster increases as to its length. In order to answer these questions, a test has been distributed among 60 Iraqi EFL Fourth-Year College students, Department of English, Colleg
... Show MoreBy using precipitation polymerization, liquid electrodes of polymers imprinted with Mebeverine hydrochloride and metronidazole benzoate were created whereas the imprinted polymer (MIP) and non imprinted (NIP) polymers were prepared by using Mebeverine hydrochloride and Metronidazole benzoate qua a template. In the polymerization process, 2-Acrylamido-2-methyl-1-propane Sulphonic acid (AMPS) or 1-Vinylimidazole (VIZ) was used qua monomer, pentaerythritol triacrylate (PETRA) or Divinylbanzene (DVB) was used qua a cross-linker while benzoyl peroxide (BPO) was used as an initiator. The MIP membranes and the membranes of NIP were created by using Dibutyl Sebacate (DBS) and Tris(2-ethylhexyl)phosphate(TEHP) qua plasticizers
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