Dental Materials

2019 ◽  
Author(s):  
Nicholas Longridge ◽  
Pete Clarke ◽  
Raheel Aftab ◽  
Tariq Ali
Keyword(s):  
Pure Sciences ◽  
Material Selection ◽  
Dental Materials ◽  
Restorative Dentistry ◽  
Hardening Material ◽  
Material Resources ◽  
Adhesive Dentistry ◽  
Concrete Production ◽  
Material Sciences

Dental material science can be a daunting subject for most dentists, given its origins in the pure sciences of physics and chemistry. Combining this with human biology, and trying to see through the fog of material manu­facturers’ commercial claims, can make it seem like a truly mystifying subject. It is important that any student of material sciences maintains a critical eye and an evidence- based approach when it comes to material selection and use. Today we are lucky enough to work with the most advanced dental materials we have ever had. But simply having such materials at your dis­posal does not ensure success. Clinical procedural techniques are often the prime focus in restorative dentistry; however, to achieve optimal aesthetics, function, and longevity from restorations, a clear under­standing of material sciences is required. Ancient Roman engineers clearly understood this concept when con­structing Rome. They had to work within the limitations imposed by the materials they had at their disposal. However, the longevity and solidity of the impressive infrastructure we see today can be attributed to their expertise in exploiting the unique properties of the material resources they had available. The Romans perfected concrete production (based on volcanic ash and lime reacting with seawater to form tobermorite crystals) to yield a water- hardening material, so durable and resistant to cracks that modern- day concrete (based on Portland cement) is still considered weaker. It can be argued whether operator skill or advancements in dental ma­terials have resulted in improvements in restorative dentistry. However, few would disagree that it is the combination of good operator skill and appropriate use of dental materials that is the key for successful long-term dentistry. Key topics include: ● Adhesive dentistry concepts ● Understanding material physical properties ● Elemental make- up of materials ● Manufacturing processing of materials ● Biocompatibility ● Appreciation of setting reactions and working time ● Appreciation of material aesthetic and optical properties.

The Biomimetic Restorative Approach

Dental Update ◽  
2021 ◽  
Vol 48 (1) ◽  
pp. 13-20
Author(s):  
Deepa N Shah
Keyword(s):  
Minimally Invasive ◽  
Thin Section ◽  
Clinical Relevance ◽  
Materials Science ◽  
Dental Materials ◽  
Clinical Protocols ◽  
Restorative Dentistry ◽  
Tooth Structure ◽  
Adhesive Dentistry ◽  
Novel Concept

Significant changes in prosthodontic considerations, with a movement away from traditional restorations and an emphasis on preservation of tooth structure, have led to the development of the concept of biomimetics in restorative dentistry. The idea of being able to design restorations, which are able to restore accurately the biomechanical, structural and aesthetic integrity of the biomechanically weakened tooth, has been embraced and adopted by clinicians globally. By combining key prosthodontic principles relating to occlusal design and the control of forces on teeth and restorations, together with minimally invasive adhesive dentistry, we are able to predictably restore the function and aesthetics of damaged dentitions without the need for aggressive tooth structure removal. Advances in dental materials science allowing minimal preparations and restorations that are strong and durable in thin section, as well as advances in adhesive dentistry have meant that the biomimetic restoration of teeth is no longer a novel concept, but something that we should all be applying as conservative and restorative dentists. CPD/Clinical Relevance: This paper describes the rationale and clinical protocols involved in the application of biomimetic restorative dentistry.

scholarly journals Smear layer on dentin in restorative dentistry

2004 ◽  
Vol 51 (4) ◽  
pp. 169-176 ◽  
Author(s):  
Slavoljub Zivkovic ◽  
Mila Kolar ◽  
Larisa Blazic ◽  
Mirjana Vucetic ◽  
Goran Tosic
Keyword(s):  
Rapid Evolution ◽  
Adhesive System ◽  
Smear Layer ◽  
Restorative Material ◽  
Structural Elements ◽  
Restorative Dentistry ◽  
Dentin Bonding ◽  
Adhesive Dentistry ◽  
Positive Results

Adhesion to enamel has become a routine technique in restorative dentistry. Adhesion to dentin, however, is still under investigation. Except structural elements of the dentin, smear layer has been one of the reasons that the interaction between the adhesive system and this tissue is difficult. The smear layer tissue created by cutting a tooth. It varies in thickness, roughness, density and degree of attachment andoccludes tubules and reduces the dental permeabilita. Dentin adhesivesystems can react with intertubular and peritubular dentin only when this smear layer is removed or when the adhesive system is capable of diffusion through layer of debris. As part of restorative procedures required by adhesive dentistry, the smear layer must be removed, modified or impregnated by the resin to allow for bonding between the tooth and the restorative material. For remove and dissolve of smear layer acid conditioners on total etch and self-etching primers were used. Self-etching primer systems are undergoing rapid evolution; their results are not yet sufficiently predictable overall, but some systems have achieved positive results in both enamel and dentin bonding. Further studies are necessary to confirm the long-term efficiency of these self-etching primers.

The PLC Research in the Program Control System of Thermal Power Coal Handling

2012 ◽  
Vol 548 ◽  
pp. 812-816
Author(s):  
Xiao Min Chen ◽  
Xi Yan Liu
Keyword(s):  
Power Plants ◽  
Rapid Development ◽  
Thermal Power ◽  
Chinese Economy ◽  
Power Requirement ◽  
Handling System ◽  
Human Power ◽  
Material Resources ◽  
Electricity System

With the rapid development of Chinese economy, the thermal power requirement is increasing not only in industry but also for the civil use in recent years. In China, the main fuel of thermal power is coal. Coal handling system places the consequence in the whole generate electricity system and has significant meaning to the power plant operation. The coal handling system of the thermal power plants has many types of equipment. The environment is vile with complicated control. If we control this system through manual mode, there will appear the imponderable questions. This article through the research of the coal handling system by the management of PLC can determine the long-term safe operation and reduce a mass of human power and material resources. It has the fundamental practical meaning and research value.

scholarly journals ABOUT CAPITAL TURNOVER AND THE METHODOLOGY OF ITS ANALYSIS

2019 ◽  
Vol 32 (1) ◽  
pp. 61-67
Author(s):  
Rositsa Ivanova
Keyword(s):  
Financial Risk ◽  
Material Resources ◽  
Industrial Enterprises ◽  
Second Stage ◽  
Economic Practice ◽  
Tangible Assets ◽  
Third Stage ◽  
The Subject ◽  
Commodity Form

Capital turnover is constantly repeating process of capital transformation from one to another form and turning it in its initial form. This process comprises capital advance for acquisition of production means and manpower, the use of the resources in the production of finished goods, sale of finished goods, and the return of capital in its original form.We will study the capital turnover with view of the stages of its movement. During the first stage, the capital is transformed from monetary into product form, as production means (long-term tangible assets and material resources) and manpower that are required for the enterprise’s business. The second stage – the stage of the production process, capital is transformed from one commodity form (production resources) in another commodity form (finished goods). During the third stage, the capital is transformed from commodity to monetary form, i.e. it recovers its original form.The issue of capital turnover is topical at all phases and stages of enterprise’s development. The acceleration of capital turnover results in release of capital embodied in different resources that can be advanced in appropriate activities, thus to increase the enterprise’s gains, and therefore – the capital return. The deceleration of capital turnover results in shortage of means required for the normal course of the enterprise’s business, and in its turn the enterprise is thus forced to raise additional funds in order to operate. This increases the share of borrowings and the level of financial risk the enterprise is exposed to.The interest to capital turnover is due to the insufficient understanding of the importance of this issue both for the successful and efficient development of enterprises’ business, as well as for the prosperity of economy as a whole. This is one of the most important issues – driver of business and economy, which is topical, irrespective of the type of ownership of the production means, the organization of the economy and the specific public and political environment. As a result of the insufficient understanding of the importance and significance of capital turnover, some thoughts exist that these are obsolete, archaic and all but unnecessary methodologies for analysis of capital turnover in the conditions of market competition.Capital turnover may be analyzed and assessed from different points of view. For example: according to the sources of its formation (equity and borrowings); according to the duration of capital involvement in the enterprise’s turnover (fixed capital and short-term borrowings); according to the resources in which the equity is embodied (share equity and working equity), etc.The object studied in this publication is the capital turnover of enterprises with industrial principal business, and the subject matter of the study covers the methodology for analysis of equity turnover with view of the resources it is embodied in.The aim of this publication is to reach a methodology for analysis and assessment of equity turnover, which is feasible for the economic practice and useful for the industrial enterprises’ management to make proper and reasonable decisions for the business development in operational and strategic aspect.

scholarly journals Sustainable Construction by Means of Improved Material Selection Process

2019 ◽  
Vol 3 (1) ◽  
pp. 85 ◽  
Author(s):  
Koorosh Gharehbaghi ◽  
Maged Georgy
Keyword(s):  
Energy Savings ◽  
Material Selection ◽  
Selection Process ◽  
Sustainable Construction ◽  
Construction Operation ◽  
Selection Factors ◽  
Strength And Durability ◽  
Operation Cost ◽  
Selection Of

Whilst sustainable construction relates to both a building’s structure and the use of proper life cycle processes, the selection of the most appropriate material/s is deemed a considerable undertaking. Throughout a building’s lifecycle that extends from design, construction, operation, maintenance, renovation, until demolition, the selection of sustainable material/s is a particularly crucial task for the development and establishment of such structures. Traditionally, there are three main materials for general construction: (1) Steel, (2) Concrete and (3) Timber. These materials not only influence the function within the structure, but also affect the operation cost and energy usage. Operation cost reduction and energy savings are typically elements of the sustainable construction sphere. However, in developing countries, there is a variety of highly critical factors, which can impact material selection as well as the long-term sustainability of the structure, including: Fire Performance, Environmental Impact, Structural Performance (strength and durability), and Functioning Capabilities. Accordingly, this paper will first compare the sustainability of these three key materials and then converse with appropriate processes for material selection. Attention will be given to the sustainable construction recompense associated with the different material selection factors. Doing so ensures a more sustainable built environment by means of an improved material selection process.

scholarly journals Characterizing the Reactivity of Metallic Iron for Water Treatment: H2 Evolution in H2SO4 and Uranium Removal Efficiency

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1523 ◽  
Author(s):  
Arnaud Igor Ndé-Tchoupé ◽  
Rui Hu ◽  
Willis Gwenzi ◽  
Achille Nassi ◽  
Chicgoua Noubactep
Keyword(s):  
Metallic Iron ◽  
Environmental Remediation ◽  
Material Selection ◽  
H2 Production ◽  
H2 Evolution ◽  
Solution Ph ◽  
Neutral Ph ◽  
Uranium Removal ◽  
Initial Reactivity

Metallic iron (Fe0) has been demonstrated as an excellent material for decentralized safe drinking water provision, wastewater treatment and environmental remediation. An open issue for all these applications is the rational material selection or quality assurance. Several methods for assessing Fe0 quality have been presented, but all of them are limited to characterizing its initial reactivity. The present study investigates H2 evolution in an acidic solution (pH 2.0) as an alternative method, while comparing achieved results to those of uranium removal in quiescent batch experiments at neutral pH values. The unique feature of the H2 evolution experiment is that quantitative H2 production ceased when the pH reached a value of 3.1. A total of twelve Fe0 specimens were tested. The volume of molecular H2 produced by 2.0 g of each Fe0 specimen in 560 mL H2SO4 (0.01 M) was monitored for 24 h. Additionally, the extent of U(VI) (0.084 mM) removal from an aqueous solution (20.0 mL) by 0.1 g of Fe0 was characterized. All U removal experiments were performed at room temperature (22 ± 2 °C) for 14 days. Results demonstrated the difficulty of comparing Fe0 specimens from different sources and confirmed that the elemental composition of Fe0 is not a stand-alone determining factor for reactivity. The time-dependent changes of H2 evolution in H2SO4 confirmed that tests in the neutral pH range just address the initial reactivity of Fe0 materials. In particular, materials initially reacting very fast would experience a decrease in reactivity in the long-term, and this aspect must be incorporated in designing novel materials and sustainable remediation systems. An idea is proposed that could enable the manufacturing of intrinsically long-term efficient Fe0 materials for targeted operations as a function of the geochemistry.

Research on Tubing and Casing Corrosion in Sour Gas Reservoirs and Corrosion-Resistant Material Selection

2013 ◽  
Vol 690-693 ◽  
pp. 1516-1519
Author(s):  
Ling Feng Li
Keyword(s):  
Material Selection ◽  
Gas Production ◽  
Resistant Material ◽  
Gas Reservoirs ◽  
Gas Well ◽  
Corrosion Resistant ◽  
System Life ◽  
Sour Gas ◽  
Selection Of

For natural gas well in sour gas reservoirs, very serious corrosion in the gas well string is an important factor of gas production system life. In order to ensure the long-term development of gas wells, this paper mainly introduces the tubing and casing corrosion in sour gas reservoirs, corrosion-resistant material selection of tubing and casing in sour gas reservoirs and proposes the optimization idea and technique of tubing material selection.. By taking W 63 well as an example, this paper optimizes the material selection of production casing for W 63 well. For application, the optimal materials of gas well string in W 63 well have good performance of corrosion resistance.

Visual and Instrumental Colorimetric Assessments of Small Color Differences on Translucent Dental Porcelain

1989 ◽  
Vol 68 (12) ◽  
pp. 1760-1764 ◽  
Author(s):  
R.R. Seghi ◽  
E.R. Hewlett ◽  
J. Kim
Keyword(s):  
Material Selection ◽  
Color Difference ◽  
Human Observer ◽  
Clinical Use ◽  
Restorative Dentistry ◽  
Colorimetric System ◽  
Color Differences ◽  
Precise Relationship ◽  
The Relationship ◽  
Further Development

The CIELAB colorimetric system was used for the study of the relationship between measured color difference values and human observer responses. This study verified that a specific, visually meaningful and precise relationship exists between the magnitude and direction of the measurements and the average dental-observer responses. The results support the use of this system in dentistry as a means of evaluating color by differences. The further development of such systems for clinical use would be warranted and could serve as a valuable tool for material selection and restoration design, particularly in the area of aesthetic restorative dentistry.

An interview with Toru Nikaido

2019 ◽  
Vol 16 (2) ◽  
pp. 6-11
Author(s):  
Toru Nikaido ◽  
Marcelo Giannini ◽  
Carlos Rocha Gomes Torres
Keyword(s):  
Dental Materials ◽  
Senior Lecturer ◽  
Adhesive Dentistry ◽  
Asian Pacific ◽  
Tokyo Medical

Dr. Nikaido formou-se como cirurgião-dentista na Universidade de Hokkaido, em 1985. No ano de 1990, finalizou o seu PhD na Tokyo Medical and Dental University (TMDU), sob a supervisão do Professor Dr. Nobuo Nakabayashi. Até o ano passado, foi professor, com cargo de “Senior Lecturer”, na área de Saúde Oral da Escola de Graduação de Ciências Médicas e Odontológicas da TMDU. Neste ano de 2019, transferiu-se para a Faculdade de Odontologia da Universidade de Asahi, cidade de Gifu, Japão, onde trabalha na divisão Oral Functional Science and Rehabilitation do Departamento de Dentística Operatória. Seus tópicos de pesquisa abordam aspectos básicos e clínicos da Odontologia Adesiva, Dentística Operatória e Odontologia Preventiva. Ele faz parte do conselho editorial de revistas científicas como Dental Materials Journal e Journal of Adhesive Dentistry. Atualmente, é o editor associado do Asian Pacific Journal of Dentistry. Foi cientista convidado no National Institute of Standards and Technology, EUA, em 1995. Foi professor visitante da Universidade Estadual de Campinas, Brasil, em 2003, e da Universidade Chulalongkorn, na Tailândia, em 2008. Já publicou mais de 150 artigos de alto nível científico. Marcelo Giannini – coordenador da entrevista

scholarly journals Circular investments as a key to solving the growth dilemma

2021 ◽  
Vol 188 (3-4) ◽  
pp. 58-68
Author(s):  
Ludmila Kormishkina ◽  
◽  
Evgenii Kormishkin ◽  
Vladimir Gorin ◽  
Dmitrii Koloskov ◽  
...  
Keyword(s):  
Raw Materials ◽  
Multiple Linear Regression Model ◽  
Raw Material ◽  
Household Waste ◽  
Negative Effects ◽  
Methodological Foundation ◽  
Material Resources ◽  
Real Gdp ◽  
Scientific Hypothesis

The rationale for this study is based on the extreme importance of finding a solution to a complex growth dilemma arising from the negative effects of human activity and the limited ability of the ecosystem to regenerate and provide resources required by mankind to ensure sustainable development and the long-term prosperity. The research is aimed at proving a scientific hypothesis that states: when the global raw-materials crisis becomes increasingly noticeable in various countries of the world, including Russia, circular investments may become a driver for long-term economic growth and the launch of far-reaching reforms of the economy in the 21st century. Circular investments in this paper are viewed as a special type of real eco-investment that combines advancements in technology and innovations to ensure renewal and industrial-scale reproduction of resources (raw materials and energy) from industrial and household waste, along with the mitigation and/or elimination of negative effects, on the environment. A multiple linear regression model has been developed to confirm a statistically-relevant connection between circular investments and real GDP. As a methodological foundation for the model, we used the classic Cobb-Douglas production function modified to take into account industrially reproduced raw material resources included in the production process. Further, we have defined major limits for circular investments in Russia today and highlighted the primary measures which are to be taken to launch circular investments in order to find a solution to the complex growth dilemma.

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