Dental composites, also known as "white fillings", are a group of restorative materials composed of a mixture of powdered glass and plastic resin regularly used in modern dentistry to resemble the appearance of the natural tooth. Acrylic resin was first introduced to the dental profession in the mid 1950s. Since their introduction, acrylic based materials have continued to play a pivotal role in restorative and prosthetic dentistry. After the introduction of the bisphenol A glycidyl methacrylate
INTRODUCTION Resin composite restorations are becoming have had a significant increase in popularity over the last few decades, and have become the patient’s preferred choice in filling material, due mainly due to their enhanced esthetics when compared to other restorations, as well as their ever-increasing durability. These factors have led to a large increase in demand from patients.1 As patient demand for this restorative material increases, so too do patient expectations for comfort and longevity
fracture toughness for resin composites Kelly Griffith, Lance Gunter, Joshua Haentges, Erik Hageman, Zohra Hasham, Nellab Hashimi Modulus of elasticity is defined as the comparative stiffness of a material. A stiffer material will have a higher elastic modulus. Fracture toughness is the amount of stress required to propagate a preexisting flaw. It describes resistance of a material with a pre-existing flaw to fail. These two properties will be evaluated for resin composites in our paper through journal
BACKGROUND Composite restoration usage in dentistry is increasing. Because of this interest in the longevity and reliability of composite fillings also is increasing1. One problem that can occur with composite restorations is micro-leakage. This is when microgaps at the tooth-restoration interface allow fluids and bacteria into the restoration2. These gaps are formed when the material is polymerized and shrinks, which causes the material to pull away from the margins of the preporation2. Problems
is a synthetic compound used worldwide in the manufacturing of plastics and epoxy resins. Derivatives of BPA are present in resin-based sealants and composites used in dentistry.1 Some of these compounds include bis-DMA (BPA dimethacrylate), bis-GMA (BPA glycidyl methacrylate) and BADGE (BPA diglycidylether).1 Although pure BPA is not utilized in dental resins, it has been demonstrated that bis-DMA has the ability to be hydrolyzed into BPA by salivary esterases.1 This is a potential cause for concern
affected tooth, if any margins between the composite restoration and tooth of concern are open, micro-leakage can occur1. Micro-leakage is a phenomenon in dentistry resulting from imperfect bonding that allows the movement of bacteria and fluids between the restoration and tooth of interest2. When a composite restoration is placed and undergoes polymerization through curing, shrinkage occurs. Research has shown that the percent of gaps between composite restorations can be variable; between 14%
Dental materials are used for a variety of reasons. The basic reason for using dental materials is to restore the tooth back to its original anatomy. Some materials are used more than others but it depends on their characteristics. Composite resin is a type of dental material. Some dental materials do not have the esthetic characteristic that composite resin has. That is why sometimes, it is more favorable than other dental materials. It is one of the most common dental materials that are used to
Dental Amalgam Amalgam dental restorations which are also known as silver fillings are the number one choice for restoring teeth. These silver fillings have been used for over a hundred years to fill in cavities where there has been decay. The question many have is “what is dental amalgam?” Dental amalgam is a mixture of materials containing powdered alloy, metals and mercury. There have been some concerns, however about the safety of this mercury containing filling material. According to the Food
Imagination and Realism in Hamlet Shakespeare’s tragic drama Hamlet is a composite of poetic and realistic elements. Which predominates? This paper analyzes the presence of both realism and imagination. Richard A. Lanham in “Superposed Plays” discusses the poetic or imaginative side of Hamlet: The real doubt comes when we ask, “What poetic do we bring to the Hamlet play?” As several of its students have pointed out, it is a wordy play. Eloquence haunts it. Horatio starts the wordiness
experience that all knowledge is therefore generated. Knowledge for Aristotle is a knowledge of universals, that is, a knowledge of Essences. Thought is thus the faculty by which we come to comprehend universals. And since material objects are a composite unity of essence and existence, it naturally follows that we grasp the universal through our encounter with the particular. What follows is a series of events which leads to knowledge. The passive intellect receives the image from the sense data
'derivatively', which derive their name from some other name, but differ from it in termination. Thus the grammarian derives his name from the word 'grammar', and the courageous man from the word 'courage'. 2 Forms of speech are either simple or composite. Examples of the latter are such expressions as 'the man runs', 'the man wins'; of the former 'man', 'ox', 'runs', 'wins'. Of things themselves some are predicable of a subject, and are never present in a subject. Thus 'man' is predicable of the
What we as humans feel is right or wrong is somehow dictated by something beyond merely the individual. The underlying question, therefore, becomes what that outside influence is: nature, our inherent human qualities themselves, or some man-made composite of other people and experiences? In more specific terms, the question is whether or not our morality and our adherence to a moral code is something fixed and constant throughout humanity itself. Francis Bacon stated that nature must first be obeyed
What attracts one person to another? The question is crucial as we consider the values of our society, the emphasis we put on physical beauty and beauty products, the new resurgence of weight loss wonder drugs and popular fad diets, not to mention a new reality TV show devoted to placing a new person under the knife for plastic surgery every week. All of these carry the same message: beauty is nearly synonymous with happiness. So then is the nature of "beauty" a philosophical conundrum, a biological
computer graphics. Congress recognized a loophole in the child pornography law, in that technological improvements have made it possible for child pornographers to use computers to "morph" or alter innocent images of actual children to create a composite image showing them in sexually explicit poses. With this in mind Congress intended to (1) ban computer-generated images that are "virtually indistinguishable" from those of real children, (2) to protect the privacy of actual children whose innocuous
the economy, society, etc. For example, we see the Jews now being able to represent themselves in court because of the new technicality which allows the oath to be taken. It is now allowed because the Christian taking the oath is swearing on a ?composite? God and more technically, a piece of paper which the Jews do not recognize as true authority (The Gospels). This shows how the social realities had changed and how the Jews had adapted to the situations by not getting rid of the text, but by instead
Mumbo Jumbo by Ishmael Reed Mumbo Jumbo is a novel about writing itself ? not only in the figurative sense of the postmodern, elf-reflexive text but also in a literal sense? [It] is both a book about texts and a book of texts, a composite narrative of subtexts, pretexts, posttexts, and narratives within narratives. It is both a definition of afro American culture and its deflation. Henry Louis Gates, Jr. Author of The Signifying Monkey Mumbo Jumbo is Ishmael Reed?s third novel and by
standard career route for today's workers. Today, many workers are pursuing varied career paths that reflect sequential career changes. This set of ongoing changes in career plans, direction, and employers portrays the lifetime progression of work as a composite of experiences. This Digest explores how changing technologies and global competitiveness have led to redefinition of interests, abilities, and work options that influence career development. Influences on Career Mobility Job mobility no longer
roman beliefs and assumptions. The assumptions of Cicero can be noticed when one inspects his view of the ideal governing body, which he expresses through Scipio (in the commonwealth). Although Cicero presents very convincing arguments for a Composite government, clearly his view is possibly only due towards his belief in the roman structure of government.1 Cicero was limited to roman borders of experience, and this point was best illustrated by his disagreement with Aristotle's writings
the undervaluation for work traditionally or historically done by women. Pay equity (also referred to as “comparable worth”) programs require a gender-neutral analysis of comparative work. A variety of very different jobs are compared based on a composite of the skill, effort and responsibility of a job and the conditions under which the job is generally done. The comparison determines the relative worth of those jobs to the achievement of a firm’s objectives, under the proposition that equal contribution
Berhad (“TM”)- Profile TM is a government-linked corporation, through its substantial shareholder Khazanah Malaysia (Khazanah), the Malaysian Government’s main investment vehicle. It is a major component of the Kuala Lumpur Stock Exchange Berhad Composite Index. In 2004, a new Group Chief Executive Officer, Dato Abdul Wahid bin Omar was appointed by Khazanah under a general revamp exercise of the GLCs. TM is the main nationwide provider of telecommunication services. It has x no of subsidiaries and