Objective. Glass-ionomer and resin-modified glass-ionomer cements are versatile materials with the ability to form a direct bond with tooth tissues. The aim of this study was to formulate a novel class of dental bio-interactive restorative material (pRMGIC) based on resin-modified glass-ionomer cements via the inclusion of an organophosphorus monomer, ethylene glycol methacrylate phosphate, with a potential to improve the mechanical properties and also function as a reparative restorative material. Methods. pRMGIC was formulated with modification of the resin phase by forming mixes of ethylene glycol methacrylate phosphate (EGMP; 0–40%wt) and 2-hydroxyethyl methacrylate monomer into the liquid phase of a RMGIC (Fuji II LC, GC Corp.). The physical properties of the cements were determined including setting characteristics, compressive strength and modulus (CS &CM), microhardness (MH) and biaxialflexural strength (BFS). Fluid uptake and fluoride release were assessed up to 60 days storage. Adhesion to sound dentine was measured using micro-tensile bond strength and surface integrity was analysed using SEM coupled with EDX. Statistical analysis was performed using ANOVA and Bonferroni post-hoc tests. Results. The pRMGIC cements exhibited an increase in working time with increasing EGMP concentration however were within the limits of standard clinical requirements. Although the compressive strength of pRMGIC cements were comparable to control cements in the early stages of maturation, the higher EGMP-containing cements (EGMP30 and 40) exhibited significantly greater values (p < 0.05) after 4 weeks storage (141.0 ± 9 and 140.4 ± 8 MPa, respectively), in comparison to EGMP0 (128.8 ± 7 MPa). A dramatic two fold increase in biaxial flexural strength (p < 0.001) was observed for the pRMGIC’s. Furthermore, the ability to decalcify tooth apatite resulted in enhanced interfacial adhesion due to chelation with calcium ions of tooth apatite. The inclusion of EGMP encouraged formation of reinforcing complexes within the RMGIC, thus improving physical properties, decreasing solubility and lower fluoride release. A dense microstructure was observed with increasing EGMP content. Significance. A novel universal bio-interactive adhesive repair material will enable clinicians to offer more effective repair of the tooth-restoration complex, thus future treatments will benefit both patient and a severely constrained healthcare budget.
Background: Propolis has received great interest because of its wide range antimicrobial activity. Propolis also called (bee glue) due to its collection by (Apismellifera) honeybees from various plants resinous substance. The aim of this study was to determine the antibacterial effect of propolis extracts (aqueous and alcoholic) on anaerobic periodontal pathogen namely Aggregatibacteractinomycetemcomitans. Materials and Methods: Strains of Aggregatibacter actinomycetemcomitans wasisolated from pockets of systemically healthy patients aged between 35-55 years old suffering from chronic periodontitis with pocket depths of 5-6 mm, the bacteria cultured on special blood Agar plates solid media. Propolis was extracted by using water and alcohol.
... Show MorePurpose: We report a series of 29 pediatric patients who sustained head injuries due to metallic ceiling fans. They all were admitted to the Emergency Department of Neurosurgery Teaching Hospital in Baghdad, Iraq, during January 2015 to January 2017. Results: Pediatric ceiling fan head injuries are characterized by four traits which distinguish them from other types of head injuries; 1- Most of them were because of climbing on or jumping from furniture between the ages of two and five. 2- Most of them sustained compound depressed skull fracture which associated with intracranial lesions and pneumocephalus. 3- The most common indication for surgical intervention was because of dirty wound which mixed with hairs. 4- These variables were stati
... Show MoreABSTRACT Background: Improving the properties of heat- cured and self-cured acrylic resin have been studied by many researchers. However, little studies concerned with visible light cured resin (VLCR) improved through addition of nanofiller are available. The purpose of this study was to evaluate some properties of (VLCR) after addition of SiO2 nanofiller. Materials and Methods: SiO2 nanofiller were added to (VLCR) tray material after being dissolved in tetrahydrofuran (THF) solvent. According to the pilot study 2% SiO2 nanofiller addition exhibited better properties than the other percentages (1%, 3%). The main study conducted involved (100) specimens divided into 5 groups according to the test included. (20) Specimens were selecte
... Show MoreThe purpose of the research is to investigate the response of stock prices of companies that issued debt instruments (bonds) listed on the Abu Dhabi Securities Exchange for information content from the Moody's first credit rating announcements for the period 1 January 2005 - 30 May 2017. The study methodology was used to verify the existence of this response by the market and the Market efficiency of the Semi-strong shape. The research focused on testing the impact of the initial announcement.The research showed that there is an influential information content to announce credit ratings in stock prices, with different responses between negative and positive. It was also found that the industrial sectors sample research separately d
... Show MoreVirtual reality, VR, offers many benefits to technical education, including the delivery of information through multiple active channels, the addressing of different learning styles, and experiential-based learning. This paper presents work performed by the authors to apply VR to engineering education, in three broad project areas: virtual robotic learning, virtual mechatronics laboratory, and a virtual manufacturing platform. The first area provides guided exploration of domains otherwise inaccessible, such as the robotic cell components, robotic kinematics and work envelope. The second promotes mechatronics learning and guidance for new mechatronics engineers when dealing with robots in a safe and interactive manner. And the thir
... Show MoreThis paper deals with one of the most important issues in a foreign language teaching and learning, i.e. speaking test assessment. After giving a survey of literature written on the meaning and definition of a speaking test assessment, two sections have been devoted to tackle the most important issues in this topic. Section one, which is the theoretical part of this paper, sheds light on the basic definitions of the term ‘speaking assessment’ which are, according to the researcher’s point of view, sufficient to cover the area of the study. This section based on applied linguistic theories and researches in order to enhance our understanding of the what is meant by «a speaking test assessment«In addition,it explains the most importan
... Show MoreE-learning is a lifeline for the educational process, which contributed to the sustainability of working educational organizations and prevented them from stopping, so the study came to measure the compatibility between E-learning quality dimensions (information technology, educational curricula, teaching methods, and intellectual capital of educational institution) as an independent variable, and educational services quality dimensions represented by (safety, tangibility, reliability and Confidence) as a dependent variable. The sample was 150 teachers was drawn from the College of Administration and Economics community of 293 teachers through the use of several statistical methods to measure the degree of correlation and impact between the
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