Influence of nitrogen ion implantation on wear studied by a new laboratory wear test

Energy Technology Data Exchange (ETDEWEB)

Szilagyi, E.; Paszti, F.; Vertessy, Z. (Central Research Inst. for Physics, Hungarian Academy of Sciences, Budapest (Hungary))

1991-05-01

A new laboratory wear test is developed in which the wear trace is measured by Rutherford backscattering spectrometry. The advantage of the new test is that the wear rate is directly determinable. The new test setup has been used to study the effects of nitrogen implantation on the wear processes on 115CrV3 steel. The wear rate decreases by a factor of 2 at 4x10{sup 17} N{sup +}/cm{sup 2} implanted dose. (orig.).

77 FR 22625 - Intermediary Lending Pilot (ILP) Program

Science.gov (United States)

2012-04-16

... years. SBA collects no fees on the loans and requires no collateral. An ILP Intermediary must use the... receive direct loans of up to $1,000,000 each. ILP Intermediaries must use the ILP Loan funds to make loans of up to $200,000 to startup, newly established, or growing small business concerns. ILP...

Organising Water: The Hidden Role of Intermediary Work

Directory of Open Access Journals (Sweden)

Timothy Moss

2009-02-01

Full Text Available The increasingly complex challenges of making water management more sustainable require a critical and detailed understanding of the social organisation of water. This paper examines the hitherto neglected role that 'intermediary' organisations play in reshaping the relations between the provision and use of water and sanitation services. In response to new regulatory, environmental, social, and commercial pressures the relationships between water utilities, consumers, and regulators are changing, creating openings for both new and existing organisations to take on intermediary functions. Drawing on recent EU-funded research we provide the first systematic analysis of intermediary organisations in the European water sector, examining the contexts of their emergence, the ways they work, the functions they perform, and the impacts they can have. With a combination of conceptual and empirical analysis we substantiate and elaborate the case for appreciating the often hidden work of intermediaries. We caution, however, against over-simplistic conclusions on harnessing this potential, highlighting instead the need to reframe perspectives on how water is organised to contemplate actor constellations and interactions beyond the common triad of provider, consumer, and regulator.

Financial Intermediaries and Economic Growth: The Nigerian Evidence

Directory of Open Access Journals (Sweden)

Oba Efayena

2014-06-01

Full Text Available This study seeks to examine the role of financial intermediaries and to find out whether financial intermediaries impact on economic growth in Nigeria. The study adopts the Harrod-Domar growth model which states that economic growth will proceed at the rate which society can mobilize domestic savings resources coupled with the productivity of the investment. The study employed the use of secondary data for the period 1981 to 2011 which were sourced from the CBN statistical bulletin. Nigerian banks being the dominant financial intermediaries, loans credits and advances from banks were used as proxy for the independent variable. Gross domestic product (GDP was used as proxy for economic growth. Using the technique of correlation analysis in determining the association between loan credits and advances, and the GDP, the study reveals a relatively high positive correlation between financial intermediaries and economic growth in the Nigerian economy. The study recommends that Nigerian banks should lend higher proportion of their loanable funds to small and medium enterprises (SMEs and should invest in information technology and human capital.

Doing things by halves: on intermediary global institutional proposals

Directory of Open Access Journals (Sweden)

Luke Ulaş

2016-06-01

Full Text Available Various cosmopolitan theorists offer global institutional prescriptions intended to be understood as residing conceptually between a system of separate domestic states and a federal world state. In this article I assess such ‘intermediary’ models, and claim that they are an unprofitable mix of idealism and misplaced pragmatism: they are ostensibly illustrations of future-oriented institutional ideals, and yet they are infused with concessions to present-day reality. In some cases, the concession is merely rhetorical: we are offered world state visions in intermediary clothing. In other cases, the concession is substantive, with the ironic result that intermediary models are in fact less feasible than the idea of a world state which intermediary theorists quickly reject. The overall aim of the argument is not to fully defend the idea of a world state, but rather only to demonstrate that there are reasons, from a cosmopolitan perspective, to consider a world state superior to intermediary models.

Develop A Framework for Selection of Intermediary in Marketing Channel

Directory of Open Access Journals (Sweden)

Hamid Reza Irani

2011-03-01

Full Text Available This study seeks to examine how a company can select the best intermediary for itsMarketing channels with minimum of criteria and time. A theoretical framework is proposed basedon the most important tasks of intermediary and the criteria to measure them. There are four basictasks and thirty criteria in three independent levels. Subsequently, an exploratory case study inIranian Food industry is described to illustrate the value of the framework. It is possible to apply thetheoretical framework to select the intermediary for any industry or country. However, there mightbe possible location-specific or industry-specific limitations. Moreover, the framework has provedto be useful in improving the selection of the intermediary in marketing channel. This is a notableand promising side-effect of the exploratory study, at least from a managerial point of view.

Intermediaries as Innovating Actors in the Transition to a Sustainable Energy System

Directory of Open Access Journals (Sweden)

Julia Backhaus

2010-07-01

Full Text Available In transitions of large sociotechnical systems, intermediary organisations can emerge as mediators in between several actor groups and facilitate communication and collaboration towards common goals. They can support the establishment of new actor networks and the articulation and alignment of interests to bring about desired changes. In this article, current efforts towards a more sustainable energy system serve as an exemplary context of intermediary work. The field under scrutiny, demand side management, aims to decrease energy consumption. Unfortunately, the role and work of intermediaries as implementers of demand side management projects often remains underappreciated.
Research into the reasons of successes and failures of intermediary work and a theoretical corroboration for their practical work can help intermediaries to improve their programme designs and implementation strategies. The EC FP7-funded Changing Behaviour project aims to support intermediaries with strategic activities to improve demand side management programmes and bring about lasting behavioural changes. Paying more attention to context, stakeholders, monitoring, evaluation and learning enables the development of tailor-made, widely supported projects with higher chances of success.
In addition to practical support for their work, intermediaries can benefit from stronger policy support. Understanding and appreciation of their work as contribution to policy implementation, e.g. towards energy saving targets, could motivate such support. A stable policy and financial environment with long-term implementation plans and funding schemes provides a fertile ground for intermediary activities. Active participation of policy actors in demand side management programmes can create networks sustaining longer-lasting change.

The World Intermediary Liability Map: Charting the Online Intermediary Liability Conundrum

OpenAIRE

Frosio, Giancarlo

2016-01-01

Whether and when access providers and communications platforms like Google, Twitter and Facebook are liable for their users’ online activities is a key factor that effects innovation and free speech. There are emerging legal, policy and ethical issues facing online intermediaries. Unfortunately, with globalized online service providers operating across the world in an interdependent digital environment, inconsistencies across different regimes generate legal uncertainties that undermine both ...

Use of intermediaries in DWI deterrence. Volume 1, Phase 2 report : development of intermediary programs

Science.gov (United States)

1983-04-01

One potential approach to DWI deterrence and prevention involves encouraging people present in potential drunk driving situations to intervene in order to prevent a trip by an impaired driver. Potential "intermediaries" include service personnel in c...

Intermediaries in sustainable urban transitions

DEFF Research Database (Denmark)

Hoffmann, Birgitte; Agger, Annika

´s, or semi public institutions. Our claim is that interme-diary actors have the potential to reach a broader scope of citizens due to their particular role in between public au-thorities and civil society. The key question of the paper is how the intermediary actors facilitate citizens' participatory...... processes in sustainable urban management and the paper explores the development of communities of practise as a way to develop learning processes and new practises? The aim is to analyse approaches of involving citizens and how they contribute to the development of new actor configurations in urban social...... the development of new practises plays a part in multi level transitions. Empirically, the article is based on case studies from Denmark of local environmental centres, green guides etc. that have performed innovative forms of involving citizens in sustainable urban development. The empirical material...

Legitimacy challenges of intermediary gatekeeping in the Chinese internet regulatory system

NARCIS (Netherlands)

Wei, Lulu

2018-01-01

Legitimacy Challenges of Intermediary Gatekeeping in the Chinese Internet Regulatory System In the Chinese legal and political framework, in order for the government to maintain control over information posted on social media platforms, commercial internet intermediaries are assigned the role of

The wisdom of the intermediary

DEFF Research Database (Denmark)

Frølund, Lars; Ziethen, Morten

2016-01-01

that the wisdom of the intermediary involves mastering the different roles (first-order wisdom) and deciding between them in each individual situation of intermediation (second-order wisdom). As a result, we advance Hargadon and Sutton’s initial insight into the human factor in intermediation, thereby further...

Intermediaries in the Management Process of Innovation

DEFF Research Database (Denmark)

Gretzinger, Susanne; Hinz, Holger; Matiaske, Wenzel

2012-01-01

Information is a critical resource in innovation processes. SMEs are therefore advised to draw on consulting in innovation processes, as they cannot ensure the necessary information flow internally due to lesser resources. From the strategic point of view, the involvement of intermediaries is acc...... is accompanied by the risk of losing specific knowledge to the business environment. But the other way around: To neglect the integration of consultancies could mean a deficit in the process of information management.......Information is a critical resource in innovation processes. SMEs are therefore advised to draw on consulting in innovation processes, as they cannot ensure the necessary information flow internally due to lesser resources. From the strategic point of view, the involvement of intermediaries...

Should Governments engage health insurance intermediaries? A comparison of benefits with and without insurance intermediary in a large tax funded community health insurance scheme in the Indian state of Andhra Pradesh.

Science.gov (United States)

Nagulapalli, Srikant; Rokkam, Sudarsana Rao

2015-09-10

A peculiar phenomenon of engaging insurance intermediaries for government funded health insurance schemes for the poor, not usually found globally, is gaining ground in India. Rajiv Aarogyasri Scheme launched in the Indian state of Andhra Pradesh, is first largest tax funded community health insurance scheme in the country covering more than 20 million poor families. Aarogyasri Health Care Trust (trust), the scheme administrator, transfers funds to hospitals through two routes one, directly and the other through an insurance intermediary. The objective of this paper is to find out if engaging an insurance intermediary has any effect on cost efficiency of the insurance scheme. We used payment data of RAS for the period 2007-12, to find out the influence of insurance intermediary on the two variables, benefit cost ratio defined as benefit payment divided by premium payment, and claim denial ratio defined as benefit payment divided by treatment cost. Relationship between scheme expenditure and number of beds empanelled under the scheme is examined. OLS regression is used to perform all analyses. We found that adding an additional layer of insurance intermediary between the trust and hospitals reduced the benefit cost ratio under the scheme by 12.2% (p-value = 0.06). Every addition of 100 beds under the scheme increases the scheme payments by US$ 0.75 million (p-value insurance and trust modes narrowed down from 2.84% in government hospitals to 0.41% in private hospitals (p-value insurance intermediary has the twin effects of reduction in benefit payments to beneficiaries, and chocking fund flow to government hospitals. The idea of engaging insurance intermediary should be abandoned.

The role of financial intermediaries in the legalization of proceeds from crime

Directory of Open Access Journals (Sweden)

Gobrusenko K. I.

2017-12-01

Full Text Available the article is about the problem of the participation of professional financial intermediaries in the legalization (laundering of proceeds from crime, and considers legislative measures of regulating the activity of such intermediaries and methods for identifying organizations that laundering money on a professional basis.

Strategic Planning of an International Trade Intermediary : Case Woodbe Oy

OpenAIRE

Matyushevskiy, Artem

2016-01-01

The intermediary company is a very important actor of supply chain because it facilitates trade between manufacturers and customers who cannot connect with each other because of physical, cultural or other obstacles. The facilitation of such kind gets even more important on international arena where cross-border obstacles can be tough. The current thesis is dedicated to strategic planning of a newly established intermediary business dealing with timber products being sold from Russia to Fi...

Supply risk management functions of sourcing intermediaries – an investigation of the clothing industry

DEFF Research Database (Denmark)

Vedel, Mette; Ellegaard, Chris

2013-01-01

Purpose: The purpose of this research is to uncover how buying companies use sourcing intermediaries to manage supply risks in global sourcing. Design/methodology/approach: We carry out an explorative qualitative study of the clothing industry, interviewing key respondents that occupy different...... intermediary types, characterised by the set of functions they handle. Research limitations/implications: By analysing a limited set of in-depth interviews in one industry we have traded off broader analytical generalization for in-depth exploration and theory building. Therefore, future research should test...... by identifying the supply risk management functions that sourcing intermediaries carry out for buying companies. We also contribute by uncovering different types of sourcing intermediaries, determined by the collection of functions handled....

Towards a Sociology of Intermediary Institutions

DEFF Research Database (Denmark)

Kjær, Poul F.

2014-01-01

be considered to be particular dense forms of the structures characterizing society as such just as changes in the setup of intermediary institutions might reflect particular clear illustrations of the transformations which society in its entirety has undergone. Developing a new understanding of the role...

Biochemist-Tree: Using Modular Origami to Understand the Integration of Intermediary Metabolism

Science.gov (United States)

Sharp, Duncan

2013-01-01

Intermediary metabolism can be a complex area to study due to the inherent modularity of the catabolic biochemical processes. This article outlines a novel, cost-effective, and universally applicable teaching activity to enhance students understanding of the inter-relationship between the key processes of intermediary metabolism. A simple origami…

Analysis Of The Logistics Intermediaries Choice Methods In The Supply Chains

Directory of Open Access Journals (Sweden)

Lukinskiy Valery

2015-12-01

Full Text Available The increase of the supply chains efficiency requires optimization of all types of logistic operations and functions. One of such functions is the choice of intermediaries (carriers, freight forwarders, suppliers, service enterprises etc. and, according to some specialists, it is a major strategic decision in management supply chains. The methods of choosing the logistic intermediaries are considered in many works, however, some questions remain debatable. The article discusses the analytical and expert approaches which serve as a basis to choose the intermediaries; along with it, in the article a comparative evaluation of choice expert methods is done: point-rating assessment, analytic hierarchy process and the general algorithm for selecting; the conclusions have been drawn about the applicability of each method.

The Brazilian approach to internet intermediary liability: blueprint for a global regime?

Directory of Open Access Journals (Sweden)

Nicolo Zingales

2015-12-01

Full Text Available While intermediary liability is becoming an issue of increasing importance in internet governance discussions, little is being made at the institutional level to minimise conflicts across jurisdictions and ensure the compliance of intermediary liability laws with fundamental rights and the freedom to innovate. The experience leading to the adoption of the Brazilian “Marco Civil da Internet” offers concrete insights for the definition of a baseline framework at the international level. This article also suggests the creation of a global forum of discussion on intermediary liability, allowing the interests of a variety of stakeholders to be taken into account in the definition and implementation of those baseline principles.

Second meeting of the Scientific Societies for the feasibility study of implantation of a synchrotron radiation national laboratory

International Nuclear Information System (INIS)

1984-01-01

Feasibility study for the implantation of a national laboratory of synchrotron radiation in Brazil is discussed by several Brazilian Scientific Societies. Problems related with cost, personnel training and machine uses are presented. (L.C.) [pt

Stock Price Manipulation: The Role of Intermediaries

Directory of Open Access Journals (Sweden)

Hammad Siddiqi

2017-10-01

Full Text Available We model a scenario in which there are three types of investors: fundamentalists, speculators, and trend-followers and an intermediary who cares about his reputation. Fundamentalists are rational investors with long horizons who are interested in the dividend stream. Speculators are rational investors who have short horizons and are interested in profiting from short-term price movements or capital gains. Trend-followers are behavioral investors who extrapolate price trends, and, consequently, are late entrants in the market. We show that an informed intermediary (broker can manipulate demand (consequently stock price without losing his reputation when there is information asymmetry. We also show that there is a trade-off between broker level competition for reputation and market liquidity. Broker level competition checks manipulation, but it adversely affects market liquidity.

Intermediaries for youth: a vital target audience.

Science.gov (United States)

1997-01-01

Worldwide, youth are recognized as a key target audience for HIV/STD awareness and prevention campaigns. Rural young people, who often have less access to information and prevention tools than urban youth, may be particularly vulnerable to HIV/STD infection. Many initiatives have been organized by nongovernmental organizations, governments, churches, and other organizations to help youth. However, parents, relatives, guardians, teachers, church and youth leaders, social workers, and other adults in a position to influence youth must also be helped to undertake the role of an intermediary between youth and HIV/STD interventions and other youth-oriented programs. In training adults to openly address sexual and reproductive health issues with adolescents, adults must first be encouraged to feel comfortable about discussing such issues among themselves. Intermediaries and how to target them are discussed.

The Modern Cult of Efficiency: Intermediary Organizations and the New Scientific Management

Science.gov (United States)

Trujillo, Tina

2014-01-01

This article analyzes one intermediary organization. It draws on critical policy studies to frame the agency's behaviors amid a discourse of managerialism in the public sector, and critical studies of education markets to explain the relationships between its reforms and education policy. Findings illustrate how the intermediary enacted…

Community socioeconomic context and its influence on intermediary determinants of child health : evidence from Colombia

OpenAIRE

Osorio Mejía, Ana María; Bolancé, Catalina; Madise, Nyovani

2014-01-01

Intermediary determinants are the most immediate mechanisms through which socioeconomic position shapes health inequities. This study examines the effect of community socioeconomic context on different indicators representing intermediary determinants of child health. In the context of Colombia, a developing country with a clear economic expansion, but one of the most unequal countries in the world, two categories of intermediary determinants, namely behavioural and psychoso...

Do intermediary institutions promote inclusiveness in PES programs? The case of Costa Rica

DEFF Research Database (Denmark)

Bosselmann, Aske Skovmand; Lund, Jens Friis

2013-01-01

Payments for environmental services (PES) are often promoted on the basis of a purported win–win scenario in terms of accomplishing dual environmental and social policy objectives. Yet, it has been observed that PES programs tend to exclude small land-owners due to relatively high and largely scale......-independent transaction costs. This study seeks to shed light on the role of local intermediaries in PES programs and how they may bring the reality of PES closer to the win–win scenario. This is done through an investigation of three intermediaries in the Costa Rican PES program; an NGO, a producer cooperative...... with landowners, as well as the land development history of the local area. Finally, the role of intermediaries is highly influenced by the framing of their working conditions by the PES program. This study thus shows the importance of considering the factors that condition the role of intermediaries in securing...

An intermediary enhances out-group trust and in-group profit expectation of Chinese but not Australians.

Science.gov (United States)

Ye, Jiawen; Ng, Sik Hung

2017-06-01

In this research, we made a theoretical distinction between direct and intermediary-mediated trust situations, and conducted a cross-cultural (Chinese vs. Australians) investment trust game to test the overlooked effects of an intermediary on investors' trust decisions, with respect to how much to invest in and expect from trustees. Compared to situations of direct trust, a nominal intermediary increased the number of Chinese investors expecting in-group trustees to repay a profit on their investments (Hypothesis 1) and raised their level of investment in out-group trustees (Hypothesis 2). These results applied to Chinese, but not Australians in support of the proposal that a nominal intermediary would serve as a cue to activate different cultural stereotypes of the functions and meanings of an intermediary with respect to trust and expectation of reciprocity. Coexisting with these culture-specific effects of an intermediary, the minimal categorisation of people into in-group and out-group on trivial grounds leads to a highly significant in-group favouritism in investment levels of both Chinese and Australians (Hypothesis 3). © 2015 International Union of Psychological Science.

Exploring the role of intermediaries in firm-user community collaborations: resolving or multiplying conflicts?

DEFF Research Database (Denmark)

Dragsdahl Lauritzen, Ghita

2015-01-01

in which they originate. Nevertheless, despite its popularity there is still a paucity of studies on intermediaries mediating firm-community collaboration. On the basis of an embedded case study, this article suggests that instead of resolving conflicts, intermediaries create a new membership construct......Research on user innovation shows that innovation can be impeded by the conflicting demands that arise in the context of collaborations between firms and their user communities. Studies argue that intermediary organizations can help to resolve these conflicts, by bridging the opposing logics...... from which new tensions arise. I propose that if intermediary organizations foster a clearer view of this membership construct, the result can be an innovative synthesis of opposing logics. Thus, I suggest a novel approach to the debate about user innovation by arguing that mediating firm...

Note on the preliminar proposal of the feasibility study for the implantation of a national laboratory of synchrotron radiation

International Nuclear Information System (INIS)

Lobo, R.; Muniz, R.P.A.

1983-01-01

Some socio-economic and political aspects on the implantation of a National Laboratory of Synchrotron Radiation in Brazil are discussed. Some applications of such a radiation, including technological ones, are presented. (L.C.) [pt

Addressing barriers to eco-innovation: Exploring the finance mobilisation functions of institutional innovation intermediaries

NARCIS (Netherlands)

Polzin, Friedemann; Flotow, von Paschen; Klerkx, L.W.A.

2016-01-01

This research article explores the role of institutional innovation intermediaries in accelerating the commercialisation of (clean) technologies. Drawing on the finance and innovation intermediaries literatures, we show that financial barriers to eco-innovation can be partly overcome by particular

76 FR 18007 - Intermediary Lending Pilot Program

Science.gov (United States)

2011-04-01

..., which are referenced in the Act's legislative history as bases for the ILP program. Requiring ILP... delinquency by an Eligible Small Business Concern. Finally, ILP Intermediaries will incur some costs of... loan request, lending history, projected lending activity, information regarding current or previous...

Travel intermediaries and responsibility for compliance with EU travel law : A scattered legal picture

NARCIS (Netherlands)

de Vries, Anne

Travel intermediaries, commonly known as travel agencies, are important and well-known actors in the travel sector and online travel agencies such as Expedia, Booking.com and AirBnB are booming. Although intermediaries obviously bring clear benefits for contracting parties, they also complicate the

Can the obstacles to privacy self-management be overcome? Exploring the consent intermediary approach

Directory of Open Access Journals (Sweden)

Tuukka Lehtiniemi

2017-07-01

Full Text Available In privacy self-management, people are expected to perform cost–benefit analysis on the use of their personal data, and only consent when their subjective benefits outweigh the costs. However, the ubiquitous collection of personal data and Big Data analytics present increasing challenges to successful privacy management. A number of services and research initiatives have proposed similar solutions to provide people with more control over their data by consolidating consent decisions under a single interface. We have named this the ‘ consent intermediary ’ approach. In this paper, we first identify the eight obstacles to privacy self-management which make cost–benefit analysis conceptually and practically challenging. We then analyse to which extent consent intermediaries can help overcome the obstacles. We argue that simply bringing consent decisions under one interface offers limited help, but that the potential of this approach lies in leveraging the intermediary position to provide aides for privacy management. We find that with suitable tools, some of the more practical obstacles indeed can become solvable, while others remain fundamentally insuperable within the individuated privacy self-management model. Attention should also be paid to how the consent intermediaries may take advantage of the power vested in the intermediary positions between users and other services.

Between international donors and local faith communities: Intermediaries in humanitarian assistance to Syrian refugees in Jordan and Lebanon.

Science.gov (United States)

Kraft, Kathryn; Smith, Jonathan D

2018-06-12

This paper explores the crucial part that faith-based organisations (FBOs) play in acting as intermediaries between international donors and local faith communities (LFCs) implementing humanitarian relief projects for Syrian refugees. Humanitarian responses to the mounting Syrian refugee crisis have coincided with greater collaboration between international donors and LFCs. This cooperation often is facilitated by a complex web of non-state intermediaries at the international, national, and local level. This study probes the breadth of roles of these intermediaries, drawing on primary data from case studies of two Christian intermediaries supporting Christian LFCs as they deliver aid primarily to Muslim Syrian refugees in Jordan and Lebanon. The results of the study are connected to the wider literature on LFCs in humanitarian response, revealing how intermediaries address issues of accountability, capacity-building, impartiality, neutrality, and professionalism. The paper concludes by offering suggestions for further research on intermediaries as key actors in the localisation of humanitarian assistance. © 2018 The Author(s). Disasters © Overseas Development Institute, 2018.

Small and Medium Enterprises using Software as a Service: Exploring the different roles of intermediaries

Directory of Open Access Journals (Sweden)

Nagarajan Venkatachalam

2014-11-01

Full Text Available Software as a Service (SaaS can provide significant benefits to small and medium enterprises (SMEs due to advantages like ease of access, 7*24 availability, and utility pricing. However, underlying the SaaS delivery model is often the assumption that SMEs will directly interact with the SaaS vendor and use a self-service approach. In practice, we see the rise of SaaS intermediaries who can support SMEs with sourcing and leveraging SaaS. This paper reports on the roles of intermediaries and how they support SMEs with using SaaS. We conducted an empirical study of two SaaS intermediaries and analysed their business models, in particular their value propositions. We identified orientation (technology or customer and alignment (operational or strategic as themes for understanding their roles. The contributions of this paper include: (1 the identification and description of SaaS intermediaries for SMEs based on an empirical study and (2 understanding the different roles of SaaS intermediaries, in particular a more basic role based on technology orientation and operational alignment and a more value adding role based on customer orientation and strategic alignment. We propose that SaaS intermediaries can address SaaS adoption and implementation challenges of SMEs by playing a basic role and can also aim to support SMEs in creating business value with SaaS based solutions by playing an added value role.

On the origin of intermediary e-government services

NARCIS (Netherlands)

Arendsen, R.; ter Hedde, M.J.; Wimmer, Maria A.; Scholl, Hans J.; Janssen, Marijn; Traunmüller, Roland

2009-01-01

The majority of SME’s tends to outsource administrative tasks, including their direct relationships with the (electronic) government. Commercial intermediary service providers therefore have to be part of governmental multi channel e-service delivery strategies. This research paper explores the

Distributed Problem Solving: Adaptive Networks with a Computer Intermediary Resource. Intelligent Executive Computer Communication

Science.gov (United States)

1991-06-01

Proceedings of The National Conference on Artificial Intelligence , pages 181-184, The American Association for Aritificial Intelligence , Pittsburgh...Intermediary Resource: Intelligent Executive Computer Communication John Lyman and Carla J. Conaway University of California at Los Angeles for Contracting...Include Security Classification) Interim Report: Distributed Problem Solving: Adaptive Networks With a Computer Intermediary Resource: Intelligent

75 FR 17743 - Ocean Transportation Intermediary License Applicants

Science.gov (United States)

2010-04-07

... Manager (Qualifying Individual) MiHwa K. Yu, Shareholder. EJ Trade Logistics LLC, 6304 NW. 97th Avenue..., DC 20573. Non-Vessel-Operating Common Carrier--Ocean Transportation Intermediary: HPK Logistics (USA... (Qualifying Individual) Jian Sun, President. Cargo Logistics International, LLC, 8761 Dorchester Road, Suite...

In situ ion irradiation/implantation studies in the HVEM-Tandem Facility at Argonne National Laboratory

International Nuclear Information System (INIS)

Allen, C.W.; Funk, L.L.; Ryan, E.A.; Taylor, A.

1988-09-01

The HVEM-Tandem User Facility at Argonne National Laboratory interfaces two ion accelerators, a 2 MV tandem accelerator and a 650 kV ion implanter, to a 1.2 MV high voltage electron microscope. This combination allows experiments involving simultaneous ion irradiation/ion implantation, electron irradiation and electron microscopy/electron diffraction to be performed. In addition the availability of a variety of microscope sample holders permits these as well as other types of in situ experiments to be performed at temperatures ranging from 10-1300 K, with the sample in a stressed state or with simultaneous determination of electrical resistivity of the specimen. This paper summarizes the details of the Facility which are relevant to simultaneous ion beam material modification and electron microscopy, presents several current applications and briefly describes the straightforward mechanism for potential users to access this US Department of Energy supported facility. 7 refs., 1 fig., 1 tab

Fiscal and monetary policy interactions in an endogenous growth model with financial intermediaries

OpenAIRE

Espinosa, Marco A.; Yip, Chong K.

1995-01-01

We review some inflationary and growth claims surrounding fiscal and monetary policy interactions. While financial intermediation has long been acknowledged as a key mechanism in the transmission of these interactions, only recently have economists incorporated the explicit modeling of such intermediaries in their analyses. Here we model financial intermediaries explicitly. We find that the relation between growth and inflation depends crucially on the agents' degree of relative risk aversion...

Designing for acceptance : Exchange design for electronic intermediaries

NARCIS (Netherlands)

Fielt, E.J.

2006-01-01

Electronic business has brought many success stories as well as failures. Intermediaries are a particularly interesting application domain: on the one hand, they are given opportunities by electronic business to reinvent their value logic, while on the other they are threatened by opportunities for

The function of intermediaries in collaborative innovation processes

DEFF Research Database (Denmark)

Hermann, Roberto Rivas; Mosgaard, Mette; Kerndrup, Søren

2016-01-01

projects related to cleaner technologies and small vessels are an understudied subject. The case study of a Danish small island ferry retrofit shows that intermediaries are important to stage the collaboration between actors. They can provide functions to the incipient network as foresight, brokering...

Supporting child witnesses during identification lineups: Exploring the effectiveness of registered intermediaries.

Science.gov (United States)

Wilcock, Rachel; Crane, Laura; Hobson, Zoe; Nash, Gilly; Kirke-Smith, Mimi; Henry, Lucy A

2018-01-01

Performance at identification lineup was assessed in eighty-five 6- to 11-year-old typically developing children. Children viewed a live staged event involving 2 male actors, and were asked to identify the perpetrators from 2 separate lineups (one perpetrator-present lineup and one perpetrator-absent lineup). Half the children took part in lineups adapted by a registered intermediary (an impartial, trained professional who facilitates understanding and communication between vulnerable witnesses and members of the justice system), and half took part in "best-practice" lineups, according to the current guidance for eyewitness identification in England and Wales. Children receiving assistance from a registered intermediary (relative to children who received best-practice lineups) were more accurate in their identifications for perpetrator-present lineups, and there was some evidence that they were also more accurate for perpetrator-absent lineups. This provides the first empirical evidence for the effectiveness of registered intermediary support during identification lineups.

Universities as Intermediaries: Impact Investing and Social Entrepreneurship

Science.gov (United States)

Tekula, Rebecca; Shah, Archana; Jhamb, Jordan

2015-01-01

Metropolitan universities are well poised in communities to be intermediaries among various actors involved in social innovation. Pace University established one of the first institutes on social entrepreneurship. Its unique position at the university level allows programming to transcend certain institutional challenges. The emerging field of…

75 FR 63476 - Ocean Transportation Intermediary License; Applicants

Science.gov (United States)

2010-10-15

.... David A. Knott dba DAK Logistics Services (NVO), 1010 Bluejay Drive, Suisun City, CA 94585. Officer... Office of Transportation Intermediaries, Federal Maritime Commission, Washington, DC 20573. ACS Logistics.... Application Type: QI Change. Archer Logistics USA LLC (NVO), 6051 Kennedy Boulevard East, PhB, West New York...

Health and safety in small enterprises in Denmark and the role of intermediaries

DEFF Research Database (Denmark)

Hasle, Peter

An analysis of the working environment for small enterprises in Denmark. Focussing especially on the working environment regulation and the role of intermediaries such as the occupational health service, the social partners and the labour inspectorate.......An analysis of the working environment for small enterprises in Denmark. Focussing especially on the working environment regulation and the role of intermediaries such as the occupational health service, the social partners and the labour inspectorate....

75 FR 42446 - Ocean Transportation Intermediary License Applicants

Science.gov (United States)

2010-07-21

... Transportation Intermediary (OTI) pursuant to section 19 of the Shipping Act of 1984 as amended (46 U.S.C... Shipping Limited (NVO), 1000 Corporate Center Drive, Suite 320, Monterey Park, CA 91754. Officers: Joey Tam, President/CEO (Qualifying Individual), Yu C. Lee, Secretary/Treasurer. Application Type: Name Change. Ever...

An ontology roadmap for crowdsourcing innovation intermediaries

OpenAIRE

Silva, Cândida; Ramos, Isabel

2014-01-01

Ontologies have proliferated in the last years, essentially justified by the need of achieving a consensus in the multiple representations of reality inside computers, and therefore the accomplishment of interoperability between machines and systems. Ontologies provide an explicit conceptualization that describes the semantics of the data. Crowdsourcing innovation intermediaries are organizations that mediate the communication and relationship between companies that aspire to solv...

Social Sustainability in Apparel Supply Chains—The Role of the Sourcing Intermediary in a Developing Country

Directory of Open Access Journals (Sweden)

Deniz Köksal

2018-03-01

Full Text Available After considering significant literature on sustainable supply chain management (SSCM, it is evident that research has neglected the social dimension and still lacks in highlighting the role of sourcing intermediaries in supply chains. The apparel supply chain has increased enormously in length and complexity, driving apparel retailers to employ sourcing intermediaries who manage their sourcing activities with suppliers from developing countries overseas. Thus, the purpose of this study is to enrich existing findings on SSCM by exploring the management of social sustainability when sourcing intermediaries are in between the focal company and the respective developing country factories. More specifically, this study aims to understand the role of apparel sourcing intermediaries for the implementation of social management strategies based on the perception of multiple supply chain actors. Qualitative data was collected through semi-structured interviews conducted in Vietnam and Europe. Ultimately ten propositions are presented, all explicitly concentrating on the apparel intermediary’s role as a significant enabler for social sustainability in apparel supply chains. The roles are social sustainability, supplier developer and coordinator, gatekeeper and safeguard, cultural broker, and social risk manager. The social sustainability roles assumed by the apparel sourcing intermediary offer great opportunities to both apparel retailers and developing country factories.

Effects of intermediary reservoir in a two-stage impedance pump

Directory of Open Access Journals (Sweden)

Lee V. C.-C.

2017-01-01

Full Text Available Impedance pump is a simple valve-less pumping mechanism, which transport fluid through the mismatch of impedance in the system. A typical open-loop impedance pump consists of an elastic tube, connected to rigid tubing, where the rigid section is connected to a reservoir. Mismatch in impedance occurs when an asymmetrical periodic excitation is exerted on the elastic tube. Studies showed that sequential excitations on the elastic tube infers higher volumetric efficiency than a single excitation. This work studies the effects of an intermediary reservoir between two excitation points on an elastic tube. This study aims to shed some light on the steady state response and fluid motion within the intermediary reservoir; in which increased volumetric efficiency is demonstrated.

Financial resources for the environment: the unsuccessful attempt to create a private financing intermediary for brownfield redevelopment projects

OpenAIRE

Keith Welkes

2005-01-01

This paper analyzes an unsuccessful attempt to establish a financing intermediary for the development of environmentally contaminated property (commonly known as brownfields) in Pennsylvania. The proposed intermediary was entitled Financial Resources for the Environment.

Widening the scope? How intermediary actors can shape energy consumption

DEFF Research Database (Denmark)

Maneschi, Davide

2013-01-01

This paper deals with energy consumption in the residential sector and with the implementation of measures to reduce it. While most research dealing with energy consumption has targeted factors and drivers at the individual user level, more recent works have highlighted collective aspects...... of (energy) consumption, both to explain the resilience of consumption patterns and to identify leverage points for the reduction of energy use. One understudied aspect of this discussion is the way “intermediary” actors – those actors who are neither policy makers, nor users, nor energy providers...... – influence energy consumption. This paper presents a review of the literature on intermediaries, providing an overview of their roles and contextualizing their functions in energy efficiency improvements. The review shows how the concept of intermediaries has been used in research dealing with innovation...

Sequential provisional implant prosthodontics therapy.

Science.gov (United States)

Zinner, Ira D; Markovits, Stanley; Jansen, Curtis E; Reid, Patrick E; Schnader, Yale E; Shapiro, Herbert J

2012-01-01

The fabrication and long-term use of first- and second-stage provisional implant prostheses is critical to create a favorable prognosis for function and esthetics of a fixed-implant supported prosthesis. The fixed metal and acrylic resin cemented first-stage prosthesis, as reviewed in Part I, is needed for prevention of adjacent and opposing tooth movement, pressure on the implant site as well as protection to avoid micromovement of the freshly placed implant body. The second-stage prosthesis, reviewed in Part II, should be used following implant uncovering and abutment installation. The patient wears this provisional prosthesis until maturation of the bone and healing of soft tissues. The second-stage provisional prosthesis is also a fail-safe mechanism for possible early implant failures and also can be used with late failures and/or for the necessity to repair the definitive prosthesis. In addition, the screw-retained provisional prosthesis is used if and when an implant requires removal or other implants are to be placed as in a sequential approach. The creation and use of both first- and second-stage provisional prostheses involve a restorative dentist, dental technician, surgeon, and patient to work as a team. If the dentist alone cannot do diagnosis and treatment planning, surgery, and laboratory techniques, he or she needs help by employing the expertise of a surgeon and a laboratory technician. This team approach is essential for optimum results.

Perspectives for Web Service Intermediaries: How Influence on Quality Makes the Difference

Science.gov (United States)

Scholten, Ulrich; Fischer, Robin; Zirpins, Christian

In the service-oriented computing paradigm and the Web service architecture, the broker role is a key facilitator to leverage technical capabilities of loose coupling to achieve organizational capabilities of dynamic customer-provider-relationships. In practice, this role has quickly evolved into a variety of intermediary concepts that refine and extend the basic functionality of service brokerage with respect to various forms of added value like platform or market mechanisms. While this has initially led to a rich variety of Web service intermediaries, many of these are now going through a phase of stagnation or even decline in customer acceptance. In this paper we present a comparative study on insufficient service quality that is arguably one of the key reasons for this phenomenon. In search of a differentiation with respect to quality monitoring and management patterns, we categorize intermediaries into Infomediaries, e-Hubs, e-Markets and Integrators. A mapping of quality factors and control mechanisms to these categories depicts their respective strengths and weaknesses. The results show that Integrators have the highest overall performance, followed by e-Markets, e-Hubs and lastly Infomediaries. A comparative market survey confirms the conceptual findings.

Neurocognitive functioning as an intermediary variable between psychopathology and insight in schizophrenia.

Science.gov (United States)

Hwang, Samuel Suk-Hyun; Ahn, Yong Min; Kim, Yong Sik

2015-12-30

Based on the neuropsychological deficit model of insight in schizophrenia, we constructed exploratory prediction models for insight, designating neurocognitive measures as the intermediary variables between psychopathology and insight into patients with schizophrenia. The models included the positive, negative, and autistic preoccupation symptoms as primary predictors, and activation symptoms as an intermediary variable for insight. Fifty-six Korean patients, in the acute stage of schizophrenia, completed the Positive and Negative Syndrome Scale, as well as a comprehensive neurocognitive battery of tests at the baseline, 8-weeks, and 1-year follow-ups. Among the neurocognitive measures, the Korean Wechsler Adult Intelligence Scale (K-WAIS) picture arrangement, Controlled Oral Word Association Test (COWAT) perseverative response, and the Continuous Performance Test (CPT) standard error of reaction time showed significant correlations with the symptoms and the insight. When these measures were fitted into the model as intermediaries between the symptoms and the insight, only the perseverative response was found to have a partial mediating effect - both cross-sectionally, and in the 8-week longitudinal change. Overall, the relationship between insight and neurocognitive functioning measures was found to be selective and weak. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

42 CFR 476.80 - Coordination with Medicare fiscal intermediaries and carriers.

Science.gov (United States)

2010-10-01

... the appropriate Medicare fiscal intermediaries and carriers of— (i) Changes as a result of DRG... prospective payment system for health care services and items; (2) Exchanging data or information; (3...

Universities' Intermediary Role in the "Design for Sustainability" Field

Science.gov (United States)

Küçüksayraç, Elif; Wever, Renee; Brezet, Han

2017-01-01

Purpose: This paper aims to investigate the intermediary role of universities in spreading design for sustainability into industry. Design/methodology/approach: Three case studies were undertaken on Delft University of Technology, Design for Sustainability Program from The Netherlands; a center on sustainable consumption and production; and Prof.…

In vitro synchrotron-based radiography of micro-gap formation at the implant-abutment interface of two-piece dental implants.

Science.gov (United States)

Rack, A; Rack, T; Stiller, M; Riesemeier, H; Zabler, S; Nelson, K

2010-03-01

Micro-gap formation at the implant-abutment interface of two-piece dental implants was investigated in vitro using high-resolution radiography in combination with hard X-ray synchrotron radiation. Images were taken with the specimen under different mechanical loads of up to 100 N. The aim of this investigation was to prove the existence of micro-gaps for implants with conical connections as well as to study the mechanical behavior of the mating zone of conical implants during loading. Synchrotron-based radiography in comparison with classical laboratory radiography yields high spatial resolution in combination with high contrast even when exploiting micro-sized features in highly attenuating objects. The first illustration of a micro-gap which was previously indistinguishable by laboratory methods underlines that the complex micro-mechanical behavior of implants requires further in vitro investigations where synchrotron-based micro-imaging is one of the prerequisites.

Metabolic interrelationships software application: Interactive learning tool for intermediary metabolism

NARCIS (Netherlands)

A.J.M. Verhoeven (Adrie); M. Doets (Mathijs); J.M.J. Lamers (Jos); J.F. Koster (Johan)

2005-01-01

textabstractWe developed and implemented the software application titled Metabolic Interrelationships as a self-learning and -teaching tool for intermediary metabolism. It is used by undergraduate medical students in an integrated organ systems-based and disease-oriented core curriculum, which

Occlusal wear of provisional implant-supported restorations.

Science.gov (United States)

Santing, Hendrik J; Kleverlaan, Cornelis J; Werner, Arie; Feilzer, Albert J; Raghoebar, Gerry M; Meijer, Henny J A

2015-02-01

Implant-supported provisional restorations should be resistant to occlusal wear. The purpose of this laboratory study was to evaluate three-body wear of three indirect laboratory composite resins, five chair side bis-acryl resin-based materials, and two chair side methacrylate-based materials used to fabricate provisional implant-supported restorations. The materials were handled and cured according to the manufacturers' instructions. The three-body wear was measured 1 day, 3 days, 7 days, 4 weeks, and 8 weeks after curing using the ACTA wear device. Wear rate decreased significantly after 8 weeks compared with the first day for all tested materials, except for Estenia C&B. The three-body wear of two indirect laboratory composite resins, that is, Estenia C&B and Solidex, was significantly less compared with all other tested materials used for fabricating provisional implant-supported restorations. Of the chair side materials, the wear rate of Protemp Crown Paste was significantly less compared with the others materials used to fabricate chair side provisional implant-supported restorations. The methacrylate-based materials, Temdent Classic and Trim, showed extreme high wear rates. Based on the results of this laboratory study on long-term wear, the use of indirect composite resin is preferred over chair side methacrylate-based materials when the provisional implant-supported restoration has to be in service for a long period of time. Of the investigated materials, only Estenia C&B and Solidex showed wear rate comparable with posterior resin composites. © 2013 Wiley Periodicals, Inc.

Pneumococcal meningitis post-cochlear implantation: preventative measures.

Science.gov (United States)

Wei, Benjamin P C; Shepherd, Robert K; Robins-Browne, Roy M; Clark, Graeme M; O'Leary, Stephen J

2010-11-01

Both clinical data and laboratory studies demonstrated the risk of pneumococcal meningitis post-cochlear implantation. This review examines strategies to prevent post-implant meningitis. Medline/PubMed database; English articles after 1980. Search terms: cochlear implants, pneumococcus meningitis, streptococcus pneumonia, immunization, prevention. Narrative review. All articles relating to post-implant meningitis without any restriction in study designs were assessed and information extracted. The presence of inner ear trauma as a result of surgical technique or cochlear implant electrode array design was associated with a higher risk of post-implant meningitis. Laboratory data demonstrated the effectiveness of pneumococcal vaccination in preventing meningitis induced via the hematogenous route of infection. Fibrous sealing around the electrode array at the cochleostomy site, and the use of antibiotic-coated electrode array reduced the risk of meningitis induced via an otogenic route. The recent scientific data support the U.S. Food and Drug Administration recommendation of pneumococcal vaccination for the prevention of meningitis in implant recipients. Nontraumatic cochlear implant design, surgical technique, and an adequate fibrous seal around the cochleostomy site further reduce the risk of meningitis. Copyright © 2010 American Academy of Otolaryngology–Head and Neck Surgery Foundation. Published by Mosby, Inc. All rights reserved.

An Exploratory Study On The Reasons Of The Takeaway Customer Using E-intermediary For Food Ordering: Yemeksepeti.com Case Study

OpenAIRE

Tomaş, Melda

2014-01-01

A number of companies have started to head for e-commerce after removing some intermediaries due to the latest advances in information technologies and widespread use of Internet, which ultimately causes some new e-intermediaries to emerge. Online takeaway food ordering systems in food and drink industry are of great samples for those e-intermediaries. The aim of this study is to investigate the reasons why the takeaway service users order via online food ordering systems instead of ordering ...

Advertising and knowledge intermediaries : Managing the ethical challenges of intangibles

NARCIS (Netherlands)

Millar, CCJM; Choi, CJ

2003-01-01

In today's business environment, the knowledge-based society, globalisation, and information and communication technologies (ICT) have increased the role of "intangible" values of assets and resources for all industries. As a result there is an increased role for knowledge intermediaries; one of

Ion Implantation Processing Technologies for Telecommunications Electronics

Energy Technology Data Exchange (ETDEWEB)

Haynes, T E

2000-05-01

The subject CRADA was a collaboration between Oak Ridge National Laboratory and Bell Laboratories, Lucent Technologies (formerly AT and T Bell Laboratories) to explore the development of ion implantation technologies for silicon integrated circuit (IC) manufacturing.

Outsourcing HR Services: The Role of Human Resource Intermediaries

Science.gov (United States)

Kock, Henrik; Wallo, Andreas; Nilsson, Barbro; Hoglund, Cecilia

2012-01-01

Purpose: In this article, the area of interest is an emerging type of organisation called human resource intermediaries (HRIs), which focus on delivering human resource (HR) services to public sector organisations and private companies. The purpose of this article is, thus, to explore HRIs as deliverers of HR services. More specifically, the…

NETWORKS AND INTERMEDIARIES IN SEASONAL AGRICULTURAL LABOR MARKETS IN TURKEY

Directory of Open Access Journals (Sweden)

Motoi Kusadokoro

2016-04-01

Full Text Available In casual labor markets, intermediaries are used in order to match employers and employees. This function is especially important when the market is imperfect and employers and employees have not formed solid networks. This paper investigates the network effects and the role of intermediaries in the seasonal agricultural labor market in the irrigated area of Adana, Turkey. The network of rural households is divided into one composed mainly of farmers and one composed mainly of seasonal agricultural workers. Our regression analyses show that the seasonal workers who do not have strong networks with farmers have difficulty finding jobs. Middlemen serve to mitigate the seasonal workers’ lack of a network and play a key role in the area’s seasonal agricultural labor market. At the same time, however, blood ties and territorial ties between middlemen and workers may cause middlemen to discriminate among seasonal workers based on their origins.

Correlates of the Intention to Implement a Tailored Physical Activity Intervention: Perceptions of Intermediaries

Directory of Open Access Journals (Sweden)

Denise Peels

2014-02-01

Full Text Available The public health impact of health behaviour interventions is highly dependent on large-scale implementation. Intermediaries—intervention providers—determine to a large extent whether an intervention reaches the target population, and hence its impact on public health. A cross-sectional study was performed to identify the correlates of intermediaries’ intention to implement a computer-tailored physical activity intervention. According to theory, potential correlates are intervention characteristics, organisational characteristics, socio-political characteristics and intermediary characteristics. This study investigated whether intermediary characteristics mediated the association between the intervention, organisational and socio-political characteristics and intention to implement the intervention. Results showed that intervention characteristics (i.e., observability (B = 0.53; p = 0.006; relative advantage (B = 0.79; p = 0.020; complexity (B = 0.80; p < 0.001; compatibility (B = 0.70; p < 0.001, organisational characteristics (i.e., type of organization (B = 0.38; p = 0.002; perceived task responsibility (B = 0.66; p ≤ 0.001; capacity (B = 0.83; p < 0.001, and the social support received by intermediary organisations (B = 0.81; p < 0.001 were associated with intention to implement the intervention. These factors should thus be targeted by an implementation strategy. Since self-efficacy and social norms perceived by the intermediary organisations partially mediated the effects of other variables on intention to implement the intervention (varying between 29% and 84%, these factors should be targeted to optimise the effectiveness of the implementation strategy.

Influence of Intermediaries on the Efficiency of Export of Small and Medium Business Production in Developing Countries

Directory of Open Access Journals (Sweden)

Arzik Miqael Suvaryan

2018-03-01

Full Text Available Small and medium business plays an important role in the national economies of developing countries. From this perspective, to create an effective system for exports is of key importance for these countries. The article provides the basis for the implementation of intermediary export organizations and systems for their interaction with small and medium business entities. On the example of Armenia, the authors proved that the introduction of intermediary organizations to enhance the participation of small and medium business in export operations is expedient. These organizations may be implemented in other developing countries. We used methods of analysis, synthesis, induction, deduction, comparative method, statistical analysis and others. The authors proposed three possible options for establishing intermediary export organizations in developing countries.. Firstly, we considered the intermediary export organizations, established and managed directly by the state. Secondly, intermediary export organizations may be created by uniting of small and medium enterprises (SMEs of a particular industry in association. And the final option is the commercial intermediary organizations for export. By applying a comparative cost analysis of direct and indirect exports, the authors have developed a method for assessing the effectiveness of interaction of intermediary export organizations with small and medium-sized businesses. We defined the following components of the total exports costs: the costs of warehousing, packaging, transportation, information collection, contracts, search for the shadow broker and interaction with him/her, marketing, export documentation, broker services, banking and insurance services, personnel costs, operation of the structure, tax and customs payments. We have analysed possible changes in these costs and defined the value of the cost changes total indicator that shows more effective indirect exports. . The study defines the

Laboratory implantation for well type ionization chambers calibration; Implantacao de um laboratorio para calibracao de camaras de ionizacao tipo poco

Energy Technology Data Exchange (ETDEWEB)

Vianello, E.A.; Dias, D.J.; Almeida, C.E. de [Laboratorio de Ciencias Radiologicas- LCR- DBB (UERJ). R. Sao Francisco Xavier, 524- Pav. HLC, sala 136 terreo- CEP 20.550-013. Rio de Janeiro (Brazil)

1998-12-31

The Radiological Science Laboratory is implanting a service for calibration of well type chambers by IAEA training program. The kerma rate in the air (mu Gy/h) of the linear Cs-137 reference source CDCS-J4 have been determined using a well type chamber Standard Imaging HDR-1000 model, which have been calibrated at Secondary Standard Laboratory Calibration of IAEA, whereas two HDR-1000 Plus chambers were calibrated too, following the same standards. The results were compared with Wisconsin University calibration certification and has demonstrated that well type ionization chamber calibration can be used in brachytherapy for several kinds of radionuclides. (Author)

Emergence of Financial Intermediaries in Electronic Markets: The Case of Online P2P Lending

OpenAIRE

Sven C. Berger; Fabian Gleisner

2009-01-01

We analyze the role of intermediaries in electronic markets using detailed data of more than 14,000 originated loans on an electronic P2P (peer-to-peer) lending platform. In such an electronic credit market, lenders bid to supply a private loan. Screening of potential borrowers and the monitoring of loan repayment can be delegated to designated group leaders. We find that these market participants act as financial intermediaries and significantly improve borrowers' credit conditions by reduci...

Organising the unorganised: Role of platform intermediaries in the Indian real estate market

Directory of Open Access Journals (Sweden)

R. Srinivasan

2017-03-01

Full Text Available A large component of the Indian economy is still in the unorganised (or informal sector. The emergence of new intermediaries leveraging the Internet has contributed significantly to organising the hitherto unorganised sector. We discuss the case of the Indian real estate industry and elucidate how Internet-based intermediaries have mitigated the problems associated with the unorganised nature of the industry. The three primary problems associated with the unorganised nature of the industry are adverse selection, moral hazard, and weak contract enforcement. Leaders representing four leading real estate platforms discuss how organising the real estate business as a platform business model helps mitigate these risks.

Improving Government service delivery with private sector intermediaries

OpenAIRE

Klievink, B.; Janssen, M.

2008-01-01

Government organizations operate a variety of channels to interact with citizens and businesses. Advances in information and communication technology enabled an online presence and more direct interactions. A focus on efficiency makes organizations encourage the use of electronic channels over traditional channels. Also, intermediaries in the service delivery chain are cut out in favor of direct interactions. This strategy of disintermediation finds its rationale in the transaction costs theo...

Evaluating the Role of Intermediaries in the Electronic Value Chain.

Science.gov (United States)

Janssen, Marijn; Sol, Henk G.

2000-01-01

Presents a business engineering methodology that supports the identification of electronic intermediary roles in the electronic value chain. The goal of this methodology is to give stakeholders insight into their current, and possible alternative, situations by means of visualization, to evaluate the added value of business models using…

What do we need from intermediaries for technology transfer to China?

DEFF Research Database (Denmark)

Li-Ying, Jason

2012-01-01

. To facilitate technology transfer between technology providers and recipients and to compensate for the weakness in the system of innovation, the role of technology intermediaries as bridging organizations has been widely recognized and discussed. This study deepens our understanding of the role...

Cooperation with Market Intermediaries in the Chinese Market

OpenAIRE

Qian, Danjun

2014-01-01

This bachelor’s thesis was commissioned by a Finnish hospitality company. The purpose of this study was to improve the cooperation between the company and its marketing intermediaries in the Chinese outbound travel market. The products of the company are promoted, distributed and sold in the Chinese outbound market mostly through tour operators and travel agencies. Therefore, finding out how to build a better relationship with them is essential for the company. The method used in this study ...

Influence of Intermediaries on the Efficiency of Export of Small and Medium Business Production in Developing Countries

OpenAIRE

Arzik Miqael Suvaryan; Narina Grigorii Mkrtichyan; Hasmik Khachik Manukyan

2018-01-01

Small and medium business plays an important role in the national economies of developing countries. From this perspective, to create an effective system for exports is of key importance for these countries. The article provides the basis for the implementation of intermediary export organizations and systems for their interaction with small and medium business entities. On the example of Armenia, the authors proved that the introduction of intermediary organizations to enhance the p...

Implant-Retained Auricular Prosthesis: A Case Report

OpenAIRE

Ozturk, A. Nilgun; Usumez, Aslihan; Tosun, Zekeriya

2010-01-01

Extraoral implant retained prosthesis have been proven to be a predictable treatment option for maxillofacial rehabilitation. This case report describes the clinical and laboratory procedures for fabricating an auricular prosthesis. In this case report, an auricular prosthesis was fabricated for a patient who lost the left and right external ear in an electrical burn. Extraoral implants and bar-and-clip retention for the proper connection of the auricular prosthesis to implant were used. This...

Promoting Islamic Private Equity Fund As An Ideal Financial Intermediary Institution

Directory of Open Access Journals (Sweden)

Nashr Akbar

2017-12-01

Full Text Available The existence of financial intermediation institution is quite necessary to support the economic activity. It serves both surplus unit and deficit unit to meet their wants whereby the former wants to invest his money in the lack of skill, while the latter wants to develop their businesses but does not have adequate capital. Bank institution is the most common institution serving the people’s need of financial intermediation. However, bank has several weaknesses that may harm and hamper the economic development. This paper aims to explore the weaknesses of banks as financial intermediary institutions and then promote Islamic Private Equity Fund as alternative. The result showed that the weaknesses of banks are: 1 fractional reserve banking, 2 fiat money, 3 debt-based investment, 4 risk averse. Furthermore, the study also found that Islamic Private Equity Fund can serve as an ideal financial intermediary institution due to some strengths: 1 no fractional reserve banking, 2 equity-based investment and 3 risk taker

Steroid implants and markers of bone turnover in steers

African Journals Online (AJOL)

jannes

Steroidal implants are used extensively in beef cattle management to take ... The practice of administering androgenic and estrogenic steroid implants to increase lean .... ELISA in bovine serum, so the assay was validated in our laboratory.

Do Research Intermediaries Reduce Perceived Coercion to Enter Research Trials Among Criminally Involved Substance Abusers?

Science.gov (United States)

Festinger, David S; Dugosh, Karen L; Croft, Jason R; Arabia, Patricia L; Marlowe, Douglas B

2011-01-01

We examined the efficacy of including a research intermediary (RI) during the consent process in reducing participants' perceptions of coercion to enroll in a research study. Eighty-four drug court clients being recruited into an ongoing study were randomized to receive a standard informed consent process alone (standard condition) or with an RI (intermediary condition). Before obtaining consent, RIs met with clients individually to discuss remaining concerns. Findings provided preliminary evidence that RIs reduced client perceptions that their participation might influence how clinical and judicial staff view them. This suggests that using RIs may improve participant autonomy in clinical studies.

7 CFR 4274.338 - Loan agreements between the Agency and the intermediary.

Science.gov (United States)

2010-01-01

...) RURAL BUSINESS-COOPERATIVE SERVICE AND RURAL UTILITIES SERVICE, DEPARTMENT OF AGRICULTURE DIRECT AND.... Upon requesting a disbursement, the intermediary must provide documentation showing that its equity..., aircraft, vehicle, marine, smoke, builder's risk, public liability, property damage, flood or mudslide, or...

Exploring the role of intermediary organizations in firm and user community collaborations: Resolving or multiplying paradoxes?

DEFF Research Database (Denmark)

Dragsdahl Lauritzen, Ghita

2015-01-01

Research on user innovation shows that innovation can be impeded by the conflicting demands that arise in the context of collaborations between firms and their user communities. One stream of research, however, applies a paradox lens to argue that intermediary organizations can help to resolve...... these conflicts, by bridging the opposing logics in which they originate. On the basis of an embedded case study, this article suggests that instead of resolving a paradox of innovation, intermediaries create new paradoxical tensions. Further, I argue that mediating firm-community collaboration is not a matter...

PIXE microbeam analysis of the metallic debris release around endosseous implants

International Nuclear Information System (INIS)

Buso, G.P.; Galassini, S.; Moschini, G.; Passi, P.; Zadro, A.; Uzunov, N.M.; Doyle, B.L.; Rossi, P.; Provencio, P.

2005-01-01

The mechanical friction that occurs during the surgical insertion of endosseous implants, both in dentistry and orthopaedics, may cause the detachment of metal debris which are dislodged into the peri-implant tissues and can lead to adverse clinical effects. This phenomenon more likely happens with coated or roughened implants that are the most widely employed. In the present study were studied dental implants screws made of commercially pure titanium and coated using titanium plasma-spray (TPS) technique. The implants were inserted in the tibia of rabbits, and removed 'en bloc' with the surrounding bone after one month. After proper processing and mounting on plastic holders, samples from bones were analysed by EDXRF setup at of National Laboratories of Legnaro, INFN, Italy, and consequently at 3 MeV proton microbeam setup at Sandia National Laboratories. Elemental maps were drawn, showing some occasional presence of metal particles in the peri-implant bone

Local Intermediary Organizations: Connecting the Dots for Children, Youth, and Families.

Science.gov (United States)

Blank, Martin J.; Brand, Betsy; Deich, Sharon; Kazis, Richard; Politz, Bonnie; Trippe, Steve

Despite the conventional wisdom that comprehensive services are an essential element in the support of children and families, over the past several decades programs and services have continued to be disconnected, separately funded, and provided by these multiple agencies. The need for local intermediaries has emerged through the devolution of…

78 FR 53423 - Notice of Funds Availability Under the Intermediary Relending Program

Science.gov (United States)

2013-08-29

... request the form. You may also write a letter containing all of the information requested in the form... DEPARTMENT OF AGRICULTURE Rural Business-Cooperative Service Notice of Funds Availability Under the Intermediary Relending Program AGENCIES: Rural Business-Cooperative Service, USDA. ACTION: Notice...

Occlusal wear of provisional implant-supported restorations

NARCIS (Netherlands)

Santing, Hendrik J.; Kleverlaan, Cornelis J.; Werner, Arie; Feilzer, Albert J.; Raghoebar, Gerry M.; Meijer, Henny J. A.

BACKGROUND: Implant-supported provisional restorations should be resistant to occlusal wear. PURPOSE: The purpose of this laboratory study was to evaluate three-body wear of three indirect laboratory composite resins, five chair side bis-acryl resin-based materials, and two chair side

Emergence of Financial Intermediaries in Electronic Markets: The Case of Online P2P Lending

Directory of Open Access Journals (Sweden)

Sven C. Berger

2009-05-01

Full Text Available We analyze the role of intermediaries in electronic markets using detailed data of more than 14,000 originated loans on an electronic P2P (peer-to-peer lending platform. In such an electronic credit market, lenders bid to supply a private loan. Screening of potential borrowers and the monitoring of loan repayment can be delegated to designated group leaders. We find that these market participants act as financial intermediaries and significantly improve borrowers' credit conditions by reducing information asymmetries, predominantly for borrowers with less attractive risk characteristics. Our findings may be surprising given the replacement of a bank by an electronic marketplace.

New delivery technology for financial services and the changing role of financial intermediaries

OpenAIRE

Buhl, Hans Ulrich

1998-01-01

New delivery technology for financial services and the changing role of financial intermediaries / H. U. Buhl ; A. Will. - In: Business Information Systems ´98 / W. Abramowicz (ed.). - Poznan : Akad. Ekonomiczna w Poznaniu, 1998. - S. 203-215

Absorption and Intermediary Metabolism of Purines and Pyrimidines in Lactating Dairy Cows

DEFF Research Database (Denmark)

Nielsen, Charlotte Stentoft; Røjen, Betina Amdisen; Jensen, Søren Krogh

2015-01-01

About 20 % of ruminal microbial N in dairy cows derives from purines and pyrimidines; however, their intermediary metabolism and contribution to the overall N metabolism has sparsely been described. In the present study, the postprandial patterns of net portal-drained viscera (PDV) and hepatic...

Importance of cochlear health for implant function.

Science.gov (United States)

Pfingst, Bryan E; Zhou, Ning; Colesa, Deborah J; Watts, Melissa M; Strahl, Stefan B; Garadat, Soha N; Schvartz-Leyzac, Kara C; Budenz, Cameron L; Raphael, Yehoash; Zwolan, Teresa A

2015-04-01

Amazing progress has been made in providing useful hearing to hearing-impaired individuals using cochlear implants, but challenges remain. One such challenge is understanding the effects of partial degeneration of the auditory nerve, the target of cochlear implant stimulation. Here we review studies from our human and animal laboratories aimed at characterizing the health of the implanted cochlea and the auditory nerve. We use the data on cochlear and neural health to guide rehabilitation strategies. The data also motivate the development of tissue-engineering procedures to preserve or build a healthy cochlea and improve performance obtained by cochlear implant recipients or eventually replace the need for a cochlear implant. This article is part of a Special Issue entitled . Copyright © 2014 Elsevier B.V. All rights reserved.

49 CFR 40.345 - In what circumstances may a C/TPA act as an intermediary in the transmission of drug and alcohol...

Science.gov (United States)

2010-10-01

... intermediary in the transmission of drug and alcohol testing information to employers? 40.345 Section 40.345 Transportation Office of the Secretary of Transportation PROCEDURES FOR TRANSPORTATION WORKPLACE DRUG AND ALCOHOL... act as an intermediary in the transmission of drug and alcohol testing information to employers? (a...

Superintendent-Business Executive Collaboration in Intermediary Organizations: Moral Agency and Democratic Functioning

Science.gov (United States)

Bennett, Jeffrey V.; McKee, Tiffany; Martin, Staci

2014-01-01

This case study describes collaboration between business executives and superintendents to influence local/regional K-12 educational change. Specifically, we examine participant like-mindedness about the ethics and appropriate focus of K-12 intermediary collaboration, the extent of democratic functioning, and key individuals to involve. Data…

The role of independent intermediaries. The case of small and medium-sized exporters

DEFF Research Database (Denmark)

Madsen, Tage Koed; Moen, Øystein; Hammervold, Randi

2012-01-01

and participation rather than just discrete types of intermediary modes (agents, importers, dealers, etc.). Associations with performance as well as the role of product and distributor characteristics are analyzed. Empirical data based on a sample of product-market ventures in 227 small and medium-sized Norwegian...... export firms are analysed by a structural equation modelling approach. The article provides empirical evidence that managers keep control of decision making to an extent that may have a negative impact on export performance. The empirical study indicates that firms should participate more in task......The article examines how small and medium-sized exporters collaborate with intermediaries in foreign markets by studying the level of control, i.e. the delegation of decisions rights and task solution. It goes one step further than previous research, since it examines degrees of control...

New orthopaedic implant management tool for computer-assisted planning, navigation, and simulation: from implant CAD files to a standardized XML-based implant database.

Science.gov (United States)

Sagbo, S; Blochaou, F; Langlotz, F; Vangenot, C; Nolte, L-P; Zheng, G

2005-01-01

Computer-Assisted Orthopaedic Surgery (CAOS) has made much progress over the last 10 years. Navigation systems have been recognized as important tools that help surgeons, and various such systems have been developed. A disadvantage of these systems is that they use non-standard formalisms and techniques. As a result, there are no standard concepts for implant and tool management or data formats to store information for use in 3D planning and navigation. We addressed these limitations and developed a practical and generic solution that offers benefits for surgeons, implant manufacturers, and CAS application developers. We developed a virtual implant database containing geometrical as well as calibration information for orthopedic implants and instruments, with a focus on trauma. This database has been successfully tested for various applications in the client/server mode. The implant information is not static, however, because manufacturers periodically revise their implants, resulting in the deletion of some implants and the introduction of new ones. Tracking these continuous changes and keeping CAS systems up to date is a tedious task if done manually. This leads to additional costs for system development, and some errors are inevitably generated due to the huge amount of information that has to be processed. To ease management with respect to implant life cycle, we developed a tool to assist end-users (surgeons, hospitals, CAS system providers, and implant manufacturers) in managing their implants. Our system can be used for pre-operative planning and intra-operative navigation, and also for any surgical simulation involving orthopedic implants. Currently, this tool allows addition of new implants, modification of existing ones, deletion of obsolete implants, export of a given implant, and also creation of backups. Our implant management system has been successfully tested in the laboratory with very promising results. It makes it possible to fill the current gap

Dancing the two-step: Collaborating with intermediary organizations as research partners to help implement workplace health and safety interventions.

Science.gov (United States)

Kramer, Desre M; Wells, Richard P; Bigelow, Phillip L; Carlan, Niki A; Cole, Donald C; Hepburn, C Gail

2010-01-01

To evaluate the effect of the involvement of intermediaries who were research partners on three intervention studies. The projects crossed four sectors: manufacturing, transportation, service sector, and electrical-utilities sectors. The interventions were participative ergonomic programs. The study attempts to further our understanding of collaborative workplace-based research between researchers and intermediary organizations; to analyze this collaboration in terms of knowledge transfer; and to further our understanding of the successes and challenges with such a process. The intermediary organizations were provincial health and safety associations (HSAs). They have workplaces as their clients and acted as direct links between the researchers and workplaces. Data was collected from observations, emails, research-meeting minutes, and 36 qualitative interviews. Interviewees were managers, and consultants from the collaborating associations, 17 company representatives and seven researchers. The article describes how the collaborations were created, the structure of the partnerships, the difficulties, the benefits, and challenges to both the researchers and intermediaries. The evidence of knowledge utilization between the researchers and HSAs was tracked as a proxy-measure of impact of this collaborative method, also called Mode 2 research. Despite the difficulties, both the researchers and the health and safety specialists agreed that the results of the research made the process worthwhile.

A Study of Search Intermediary Working Notes: Implications for IR System Design.

Science.gov (United States)

Spink, Amanda; Goodrum, Abby

1996-01-01

Reports findings from an exploratory study investigating working notes created during encoding and external storage (EES) processes by human search intermediaries (librarians at the University of North Texas) using a Boolean information retrieval (IR) system. Implications for the design of IR interfaces and further research is discussed.…

Intermediary object for participative design processes based on the ergonomic work analysis

DEFF Research Database (Denmark)

Souza da Conceição, Carolina; Duarte, F.; Broberg, Ole

2012-01-01

The objective of this paper is to present and discuss the use of an intermediary object, built from the ergonomic work analysis, in a participative design process. The object was a zoning pattern, developed as a visual representation ‘mapping’ of the interrelations among the functional units of t...

The quality of insurance intermediary services: An analysis of conduct and performance in the German market of insurance intermediation

OpenAIRE

Eckardt, Martina

2006-01-01

Based on a sample of 946 German insurance intermediaries, the factors that affect the quality of the information services provided by them are studied using OLS-estimations. Applying a search theoretical approach, we analyze the impact of supply and demand side variables on service quality. Besides, the working of signaling devices (like reputation, advertising or certificates) to reduce asymmetric information with respect to the service quality of insurance intermediaries is examined. The re...

Intermediaries, Cash Economies,and Technological Change in Myanmar and India

OpenAIRE

Oreglia, Elisa; Srinivasan, Janaki

2016-01-01

Why do financial intermediaries persist, despite the promises of disintermediation that accompanied the diffusion of digital technologies?Through a comparative qualitative study of financial intermediation in rural markets in Shan State, Myanmar, and Kerala, India, we map out and make visible official and unofficial roles played by different types of brokers (traders, hundi, transport companies, etc.), and different financial  tools (cash, gold, land, banks, etc.), and look at how information...

42 CFR 405.1803 - Intermediary determination and notice of amount of program reimbursement.

Science.gov (United States)

2010-10-01

... program reimbursement. 405.1803 Section 405.1803 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES... Provider Reimbursement Determinations and Appeals § 405.1803 Intermediary determination and notice of amount of program reimbursement. (a) General requirement. Upon receipt of a provider's cost report, or...

From Ice Sheets to Main Streets: Intermediaries Connect Climate Scientists to Coastal Adaptation

Science.gov (United States)

Ultee, Lizz; Arnott, James C.; Bassis, Jeremy; Lemos, Maria Carmen

2018-03-01

Despite the societal relevance of sea-level research, a knowledge-to-action gap remains between researchers and coastal communities. In the agricultural and water-management sectors, intermediaries such as consultants and extension agencies have a long and well-documented history of helping to facilitate the application of scientific knowledge on the ground. However, the role of such intermediaries in adaptation to sea-level rise, though potentially of vital importance, has been less thoroughly explored. In this commentary, we describe three styles of science intermediation that can connect researchers working on sea-level projections with decision-makers relying on those projections. We illustrate these styles with examples of recent and ongoing contexts for the application of sea-level research, at different spatial scales and political levels ranging from urban development projects to international organizations. Our examples highlight opportunities and drawbacks for the researchers involved and communities adapting to rising seas.

Customizable cap implants for neurophysiological experimentation.

Science.gov (United States)

Blonde, Jackson D; Roussy, Megan; Luna, Rogelio; Mahmoudian, Borna; Gulli, Roberto A; Barker, Kevin C; Lau, Jonathan C; Martinez-Trujillo, Julio C

2018-04-22

Several primate neurophysiology laboratories have adopted acrylic-free, custom-fit cranial implants. These implants are often comprised of titanium or plastic polymers, such as polyether ether ketone (PEEK). Titanium is favored for its mechanical strength and osseointegrative properties whereas PEEK is notable for its lightweight, machinability, and MRI compatibility. Recent titanium/PEEK implants have proven to be effective in minimizing infection and implant failure, thereby prolonging experiments and optimizing the scientific contribution of a single primate. We created novel, customizable PEEK 'cap' implants that contour to the primate's skull. The implants were created using MRI and/or CT data, SolidWorks software and CNC-machining. Three rhesus macaques were implanted with a PEEK cap implant. Head fixation and chronic recordings were successfully performed. Improvements in design and surgical technique solved issues of granulation tissue formation and headpost screw breakage. Primate cranial implants have traditionally been fastened to the skull using acrylic and anchor screws. This technique is prone to skin recession, infection, and implant failure. More recent methods have used imaging data to create custom-fit titanium/PEEK implants with radially extending feet or vertical columns. Compared to our design, these implants are more surgically invasive over time, have less force distribution, and/or do not optimize the utilizable surface area of the skull. Our PEEK cap implants served as an effective and affordable means to perform electrophysiological experimentation while reducing surgical invasiveness, providing increased strength, and optimizing useful surface area. Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.

A New Direction for Technology-Based Economic Development: The Role of Innovation Intermediaries

Science.gov (United States)

Bendis, Richard A.; Seline, Richard S.; Byler, Ethan J.

2008-01-01

Accelerating innovation to drive economic growth is the foremost goal for technology-based economic development organizations today. Realizing this goal through programmes is challenged by limited and outdated operating models. The authors outline their 21st Century Innovation Intermediary model, which pairs commercialization with regional…

13 CFR 120.703 - How does an organization apply to become an Intermediary?

Science.gov (United States)

2010-01-01

... area; (6) The applicant's experience and qualifications in providing marketing, management, and... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false How does an organization apply to become an Intermediary? 120.703 Section 120.703 Business Credit and Assistance SMALL BUSINESS...

Promoting reading skills or wasting time? Students’ perceived benefits of reading in an intermediary programme at the Vaal University of Technology

Directory of Open Access Journals (Sweden)

Linda Scott

2016-05-01

Full Text Available Notwithstanding the substantial transformation of education in South Africa in the last 20 years, specifically to redress the past inequalities, the challenges are ongoing. These challenges include tertiary institutions having to accommodate a culturally and linguistically diverse group of students, often second-language (L2 English speakers, in an English lingua franca classroom. This study investigated the reading attitudes and habits of students in an intermediary programme of a tertiary institution and any perceived changes to these attitudes or habits, as well as their perceptions of the promotion of reading by the programme. On successful completion of the intermediary programme, students register for the compulsory first-year English distance learning course and are required to complete a placement test. Results for students who attended the intermediary programme were compared with those of students who did not attend the intermediary programme but registered directly for mainstream. The teaching of reading appeared invaluable at the tertiary level with the indication that students’ attitudes and behaviour changed and that they inter alia realised the academic value thereof, made decisions to take up reading as a hobby and discovered new genres. Keywords: Reading; Linguistically diverse

13 CFR 120.1010 - SBA access to SBA Lender, Intermediary, and NTAP files.

Science.gov (United States)

2010-01-01

... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false SBA access to SBA Lender, Intermediary, and NTAP files. 120.1010 Section 120.1010 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION BUSINESS LOANS Risk-Based Lender Oversight Supervision § 120.1010 SBA access to SBA Lender...

Strength of titanium intramedullary implant versus miniplate fixation of mandibular condyle fractures.

Science.gov (United States)

Frake, Paul C; Howell, Rebecca J; Joshi, Arjun S

2012-07-01

To test the strength of internal fixation of mandibular condyle fractures repaired with titanium miniplates versus titanium intramedullary implants. Prospective laboratory experimentation in urethane mandible models and human cadaveric mandibles. Materials testing laboratory at an academic medical center. Osteotomies of the mandibular condyle were created in 40 urethane hemimandible models and 24 human cadaveric specimens. Half of the samples in each group were repaired with traditional miniplates, and the other half were repaired with intramedullary titanium implants. Anteroposterior and mediolateral loads were applied to the samples, and the displacement was measured with reference to the applied force. Titanium intramedullary implants demonstrated statistically significant improved strength and stiffness versus miniplates in the urethane model experimental groups. Despite frequent plastic deformation and mechanical failures of the miniplates, a 1.6-mm-diameter titanium intramedullary pin did not mechanically fail in any of the cases. Intramedullary implantation failures were due to secondary fracture of the adjacent cortical bone or experimental design limitations including rotation of the smooth pin implant. Mechanical implant failures that were encountered with miniplate fixation were not seen with titanium intramedullary implants. These intramedullary implants provide stronger and more rigid fixation of mandibular condyle fractures than miniplates in this in vitro model.

Intermediaries in agro-food networks in Turkey: How middlemen respond to transforming food market structures

Directory of Open Access Journals (Sweden)

Appel, Alexandra

2014-09-01

Full Text Available Traditional wholesale intermediaries in the fresh fruit and vegetable segment tend to get expendable in markets with an increasing demand for traceability and for the fulfilment of quality and hygiene standards. The demand for these specifications is usually induced by transnational retail corporations that enter new market environments. This is also the case for Turkey, where since 2010 trade with fresh fruit and vegetable products can be conducted outside wholesale markets. Dualistic structures in accordance with socio-economic realities have emerged and the reactions of intermediaries towards these transformations vary between strategies of resilience and reworking. Therefore completely new purchasing channels emerge, whereby at the same time long-established trading patterns remain important to supply all groups of the society. This article is based on interviews conducted in Turkey.

The effect of thread pattern upon implant osseointegration.

Science.gov (United States)

Abuhussein, Heba; Pagni, Giorgio; Rebaudi, Alberto; Wang, Hom-Lay

2010-02-01

Implant design features such as macro- and micro-design may influence overall implant success. Limited information is currently available. Therefore, it is the purpose of this paper to examine these factors such as thread pitch, thread geometry, helix angle, thread depth and width as well as implant crestal module may affect implant stability. A literature search was conducted using MEDLINE to identify studies, from simulated laboratory models, animal, to human, related to this topic using the keywords of implant thread, implant macrodesign, thread pitch, thread geometry, helix angle, thread depth, thread width and implant crestal module. The results showed how thread geometry affects the distribution of stress forces around the implant. A decreased thread pitch may positively influence implant stability. Excess helix angles in spite of a faster insertion may jeopardize the ability of implants to sustain axial load. Deeper threads seem to have an important effect on the stabilization in poorer bone quality situations. The addition of threads or microthreads up to the crestal module of an implant might provide a potential positive contribution on bone-to to-implant contact as well as on the preservation of marginal bone; nonetheless this remains to be determined. Appraising the current literature on this subject and combining existing data to verify the presence of any association between the selected characteristics may be critical in the achievement of overall implant success.

Enhanced wear resistance of production tools and steel samples by implantation of nitrogen and carbon ions

International Nuclear Information System (INIS)

Mikkelsen, N.J.; Straede, C.A.

1992-01-01

In recent years ion implantation has become a feasible technique for obtaining improved wear resistance of production tools. However, basic knowledge of how and in which cases ion implantation is working at its best is still needed. The present paper discusses structural and tribological investigations of carbon and nitrogen implanted steels. The nitrogen data were obtained mainly from field tests and the investigation of carbon implantations took place mainly in the laboratory. A study was made of how the tribological behaviour of implanted steels changes with different implantation parameters. The tribological laboratory investigations were carried out using pin-on-disc equipment under controlled test conditions, and deal with high dose carbon implantation (approximately (1-2)x10 18 ions cm -2 ). The wear resistance of steels was enhanced dramatically, by up to several orders of magnitude. The field test results cover a broad range of ion implanted production tools, which showed a marked improvement in wear resistance. Nitrogen implanted tools are also compared with carbon and titanium implanted tools. (orig.)

Autologous Chondrocyte Implantation in Osteoarthritic Surroundings

DEFF Research Database (Denmark)

Ossendorff, Robert; Grad, Sibylle; Stoddart, Martin J

2018-01-01

BACKGROUND: Autologous chondrocyte implantation (ACI) fails in up to 20% of cases. Advanced intra-articular degeneration paired with an inflammatory environment may be closely related to implantation failure. Certain cytokines have been identified to play a major role during early osteoarthritis....... PURPOSE: To investigate the effects of tumor necrosis factor α (TNFα) and its potential inhibition by adalimumab on cartilage regeneration in an in vitro model of ACI. STUDY DESIGN: Controlled laboratory study. METHODS: Bovine articular chondrocytes were cultivated and transferred at passage 3 to fibrin...

Development of Linear Mode Detection for Top-down Ion Implantation of Low Energy Sb Donors

Science.gov (United States)

Pacheco, Jose; Singh, Meenakshi; Bielejec, Edward; Lilly, Michael; Carroll, Malcolm

2015-03-01

Fabrication of donor spin qubits for quantum computing applications requires deterministic control over the number of implanted donors and the spatial accuracy to within which these can be placed. We present an ion implantation and detection technique that allows us to deterministically implant a single Sb ion (donor) with a resulting volumetric distribution of performed, in part, at the Center for Integrated Nanotechnologies, a U.S. DOE Office of Basic Energy Sciences user facility. The work was supported by Sandia National Laboratories Directed Research and Development Program. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a Lockheed-Martin Company, for the U. S. Department of Energy under Contract No. DE-AC04-94AL85000.

Implantable optical-electrode device for stimulation of spinal motoneurons

International Nuclear Information System (INIS)

Matveev, M V; Erofeev, A I; Zakharova, O A; Vlasova, O L; Pyatyshev, E N; Kazakin, A N

2016-01-01

Recent years, optogenetic method of scientific research has proved its effectiveness in the nerve cell stimulation tasks. In our article we demonstrate an implanted device for the spinal optogenetic motoneurons activation. This work is carried out in the Laboratory of Molecular Neurodegeneration of the Peter the Great St. Petersburg Polytechnic University, together with Nano and Microsystem Technology Laboratory. The work of the developed device is based on the principle of combining fiber optic light stimulation of genetically modified cells with the microelectrode multichannel recording of neurons biopotentials. The paper presents a part of the electrode implant manufacturing technique, combined with the optical waveguide of ThorLabs (USA). (paper)

Evaluating stakeholder participation in water management: intermediary outcomes as potential indicators for future resource management outcomes

Science.gov (United States)

Carr, Gemma; Bloeschl, Guenter; Loucks, Daniel Pete

2013-04-01

Evaluation of participation programmes, projects and activities is essential to identify whether stakeholder involvement has been successful in achieving its aims. Aims may include an improvement in water resource management such as enhanced ecological functioning, an improvement in human wellbeing and economic conditions, or overcoming a conflict between interest groups. Evaluating against "interest-based" resource management criteria requires that a desirable outcome can be identified, agreed upon and be measured at the time of evaluation. In many water management situations where collaborative approaches are applied, multiple interests and objectives are present, or stakeholders have not yet identified their own positions and priorities. Even if a resource management objective has been identified and strategy agreed upon, resource management changes tend to emerge over longer timescales and evaluation frequently takes place before they can be recognised. Evaluating against resource management criteria may lead evaluators to conclude that a programme has failed because it has not achieved a resource management objective at the time of evaluation. This presents a critical challenge to researchers assessing the effectiveness of stakeholder participation programmes. One strategy to overcome this is to conduct "goal-free" evaluation to identify what the programme is actually achieving. An evaluation framework that includes intermediary outcomes that are both tangible achievements such as innovation, creation of new organisations, and shared information and knowledge, as well as intangible achievements such as trust and network development can be applied to more broadly assess a programme's success. Analysis of case-studies in the published literature for which a resource management outcome has been achieved shows that intermediary outcomes frequently precede resource management outcomes. They seem to emerge over shorter timescales than resource management outcomes

Calculation laboratory: game based learning in exact discipline

Directory of Open Access Journals (Sweden)

André Felipe de Almeida Xavier

2017-12-01

Full Text Available The Calculation Laboratory appeared with the need to give meaning to the learning of students entering the courses of Engineering, in the discipline of Differential Calculus, in the semester 1/2016. After obtaining good results, the activity was also extended to the classes of Analytical Geometry and Linear Algebra (GAAL and Integral Calculus, so that these incoming students could continue the process. Historically, students present some difficulty in these contents, and it is necessary to give meaning to their learning. Given the table presented, the Calculation Laboratory aims to give meaning to the contents worked, giving students autonomy, having the teacher as the tutor, as intermediary between the student and the knowledge, creating various practical, playful and innovative activities to assist in this process. Through this article, it is intended to report a little about the activities created to facilitate this process of execution of the Calculation Laboratory, in addition to demonstrating the results obtained and measured after its application. Through these proposed activities, it is noticed that the student is gradually gaining autonomy in the search for knowledge.

Characterization of an Mg-implanted GaN p-i-n Diode

Science.gov (United States)

2016-03-31

Characterization of an Mg- implanted GaN p-i-n Diode Travis J. Anderson, Jordan D. Greenlee, Boris N. Feigelson, Karl D. Hobart, and Francis J...Kub Naval Research Laboratory, Washington, DC 20375 Abstract: A p-i-n diode formed by the implantation of Mg in GaN was fabricated and...characterized. After implantation , Mg was activated using the symmetrical multicycle rapid thermal annealing technique with heating pulses up to 1340C

26 CFR 1.643(h)-1 - Distributions by certain foreign trusts through intermediaries.

Science.gov (United States)

2010-04-01

... intermediaries. 1.643(h)-1 Section 1.643(h)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Estates, Trusts, and Beneficiaries § 1.643(h)-1... section, FT is deemed to have distributed XYZ stock with a value of 85X to C on December 1, 2001. (h...

Linking shallow, Linking deep : how scientific intermediaries use the Web for their network of collaborators

NARCIS (Netherlands)

Vasileiadou, E.; Besselaar, van den P.

2006-01-01

In this paper we explore the possibility of using Web links to study collaborations between organisations, combining the results of qualitative analysis of interviews and quantitative analysis of linking patterns. We use case studies of scientific intermediaries, that is, organisations that mediate

77 FR 22576 - Possible Revocation of Ocean Transportation Intermediary License No. 021899-Trans World Logistics...

Science.gov (United States)

2012-04-16

... Intermediary License No. 021899--Trans World Logistics Corporation; Order To Show Cause Trans World Logistics Corporation (Trans World Logistics) is an Indiana corporation, incorporated in October 2006. Records... Logistics maintains its principal offices at 702 Penny Lane, Plainfield, Indiana. BCL records identify the...

Intermediary cooperative associations and the institutionalization of participative work practices

DEFF Research Database (Denmark)

Sørensen, Ole Henning; Doellgast, Virginia; Bojesen, Anders

2015-01-01

of the Centre for the Development of Human Resources and Quality Management (SCKK), a social partnership-based organization that funds workplace development Projects at state workplaces, and of nine participative development projects that received financial and logistical support from the SCKK. These projects...... increased union and management commitment to partnership-based approaches to problem-solving, despite their ambiguous results for both groups. This suggests that intermediary cooperative associations help to enhance the normative legitimacy of participative work practices through the provision of resources...... and ‘best practice’ management approaches....

ICT Strategies of Democratic Intermediaries : A View on the Political System in the Digital Age

NARCIS (Netherlands)

A.R. Edwards (Arthur)

2006-01-01

textabstractA conceptual framework is proposed for discussing the ICT strategies of intermediaries and their effects on democratic intermediation. The main line of reasoning is that both ‘disintermediation’ and ‘re-intermediation’ have to be related to specific models of democracy and styles of

Zooming in on regulatory intermediaries: The impact of non-state regulators on sustainable construction practice

NARCIS (Netherlands)

van der Heijden, J.

2014-01-01

Levi-Faur and Starobin (2013) have recently drawn our attention to the important role of regulatory intermediates in contemporary regulatory regimes. Among others they argue that regulatory intermediaries come in a wide variety of appearances, and that these can influence the outcomes of regulatory

Insulin resistance in type 1 (insulin-dependent) diabetes: dissimilarities for glucose and intermediary metabolites

NARCIS (Netherlands)

Nijs, H. G.; Radder, J. K.; Poorthuis, B. J.; Krans, H. M.

1990-01-01

To study insulin action on intermediary metabolism in relation to glucose disposal in Type 1 (insulin-dependent) diabetes, 29 patients and 15 control subjects underwent sequential euglycemic clamps (insulin infusion rates 0.5, 1.0, 2.0 and 5.0 mU.kg-1.min-1 in 2 hour periods). Dose-response curves

A Novel Percutaneous Electrode Implant for Improving Robustness in Advanced Myoelectric Control

Directory of Open Access Journals (Sweden)

Janne M. Hahne

2016-03-01

Full Text Available Despite several decades of research, electrically powered hand and arm prostheses are still controlled with very simple algorithms that process the surface electromyogram (EMG of remnant muscles to achieve control of one prosthetic function at a time. More advanced machine learning methods have shown promising results under laboratory conditions. However, limited robustness has largely prevented the transfer of these laboratory advances to clinical applications. In this paper, we introduce a novel percutaneous EMG electrode to be implanted chronically with the aim of improving the reliability of EMG detection in myoelectric control. The proposed electrode requires a minimally invasive procedure for its implantation, similar to a cosmetic micro-dermal implant. Moreover, being percutaneous, it does not require power and data telemetry modules. Four of these electrodes were chronically implanted in the forearm of an able-bodied human volunteer for testing their characteristics. The implants showed significantly lower impedance and greater robustness against mechanical interference than traditional surface EMG electrodes used for myoelectric control. Moreover, the EMG signals detected by the proposed systems allowed more stable control performance across sessions in different days than that achieved with classic EMG electrodes. In conclusion, the proposed implants may be a promising interface for clinically available prostheses.

Optical system optimization of the microprobe beamline of the Ion Implantation Laboratory (IF-UFRGS), Brazil

International Nuclear Information System (INIS)

Bauer, Deiverti de Vila

2015-01-01

The aim of the present work is to optimize the microprobe beamline of the Ion Implantation Laboratory (IF-UFRGS). In short, an ion microprobe consists of charged particles focused to the dimensions of a few micrometers. The focusing system is made of two slits for demagnification, a set of magnetic lenses with scanning capability and a reaction chamber. By changing the parameters related to this system, one can optimize the features of the beam. To that end, samples of poly(tereftalate etylene) were irradiated with 2.2 MeV H+ ions and etched, yielding 2D microstructures with high aspect ratio. The analysis of the structures with Scanning Electron Microscopy proved to be an important tool in order to establish a correlation between the size of the microstructures and the parameters of the focusing system. In this work, the causes leading to a beam enlargement are discussed, as well as the aberrations which affect the system. Finally, the advantages of using ions for lithography purposes is pointed out. (author)

46 CFR Appendix C to Subpart C of... - Ocean Transportation Intermediary (OTI) Guaranty Form [Form 68

Science.gov (United States)

2010-10-01

..., or its legal responsibilities under the 1984 Act and the rules and regulations of the FMC, made by... AFFECTING OCEAN SHIPPING IN FOREIGN COMMERCE LICENSING, FINANCIAL RESPONSIBILITY REQUIREMENTS, AND GENERAL DUTIES FOR OCEAN TRANSPORTATION INTERMEDIARIES Financial Responsibility Requirements; Claims Against...

Failure analysis of fractured dental zirconia implants.

Science.gov (United States)

Gahlert, M; Burtscher, D; Grunert, I; Kniha, H; Steinhauser, E

2012-03-01

The purpose of the present study was the macroscopic and microscopic failure analysis of fractured zirconia dental implants. Thirteen fractured one-piece zirconia implants (Z-Look3) out of 170 inserted implants with an average in situ period of 36.75±5.34 months (range from 20 to 56 months, median 38 months) were prepared for macroscopic and microscopic (scanning electron microscopy [SEM]) failure analysis. These 170 implants were inserted in 79 patients. The patient histories were compared with fracture incidences to identify the reasons for the failure of the implants. Twelve of these fractured implants had a diameter of 3.25 mm and one implant had a diameter of 4 mm. All fractured implants were located in the anterior side of the maxilla and mandibula. The patient with the fracture of the 4 mm diameter implant was adversely affected by strong bruxism. By failure analysis (SEM), it could be demonstrated that in all cases, mechanical overloading caused the fracture of the implants. Inhomogeneities and internal defects of the ceramic material could be excluded, but notches and scratches due to sandblasting of the surface led to local stress concentrations that led to the mentioned mechanical overloading by bending loads. The present study identified a fracture rate of nearly 10% within a follow-up period of 36.75 months after prosthetic loading. Ninety-two per cent of the fractured implants were so-called diameter reduced implants (diameter 3.25 mm). These diameter reduced implants cannot be recommended for further clinical use. Improvement of the ceramic material and modification of the implant geometry has to be carried out to reduce the failure rate of small-sized ceramic implants. Nevertheless, due to the lack of appropriate laboratory testing, only clinical studies will demonstrate clearly whether and how far the failure rate can be reduced. © 2011 John Wiley & Sons A/S.

Adhesive, abrasive and oxidative wear in ion-implanted metals

International Nuclear Information System (INIS)

Dearnaley, G.

1985-01-01

Ion implantation is increasingly being used to provide wear resistance in metals and cemented tungsten carbides. Field trials and laboratory tests indicate that the best performance is achieved in mild abrasive wear. This can be understood in terms of the classification of wear modes (adhesive, abrasive, oxidative etc.) introduced by Burwell. Surface hardening and work hardenability are the major properties to be enhanced by ion implantation. The implantation of nitrogen or dual implants of metallic and interstitial species are effective. Recently developed techniques of ion-beam-enhanced deposition of coatings can further improve wear resistance by lessening adhesion and oxidation. In order to support such hard coatings, ion implantation of nitrogen can be used as a preliminary treatment. There is thus emerging a versatile group of related hard vacuum treatments involving intense beams of nitrogen ions for the purpose of tailoring metal surfaces to resist wear. (Auth.)

13 CFR 120.712 - How does an Intermediary get a grant to assist Microloan borrowers?

Science.gov (United States)

2010-01-01

... contribution. It may only use grant funds to provide Microloan borrowers with marketing, management, and... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false How does an Intermediary get a grant to assist Microloan borrowers? 120.712 Section 120.712 Business Credit and Assistance SMALL...

Intermediary objects in the workspace design process: means of experience transfer in the offshore sector

DEFF Research Database (Denmark)

Souza da Conceição, Carolina; Silva, Gislaine; Broberg, Ole

2012-01-01

The aim of this paper is to discuss the use of intermediary objects in the workspace design process of offshore accommodations module. The integration of ergonomics in the design process can lead to better work conditions, more effectiveness in the work process and less health and safety issues...

Intermediaries in the ‘Design for Sustainability’ Field : Strategies for Developing Innovation Support Mechanisms in Turkey

NARCIS (Netherlands)

Küçüksayraç, E.

2015-01-01

Design for sustainability is a key approach for achieving sustainable development. This PhD study investigates innovation support for companies working on design for sustainability and intermediaries that provide innovation support. The study focuses on Turkey, where design for sustainability is not

Ion implantation in metals

International Nuclear Information System (INIS)

Vook, F.L.

1977-02-01

The application of ion beams to metals is rapidly emerging as a promising area of research and technology. This report briefly describes some of the recent advances in the modification and study of the basic properties of metals by ion implantation techniques. Most of the research discussed illustrates some of the new and exciting applications of ion beams to metals which are under active investigation at Sandia Laboratories, Albuquerque

Nitrogen ion implantation: Barriers to industrial acceptance and prospects for the future

International Nuclear Information System (INIS)

Alexander, R.B.

1989-01-01

Nitrogen ion implantation has been used to improve the wear and fatigue resistance of metals in industrial applications since the process was developed at the UK Harwell Laboratory in the 1970s. However, implantation service companies like Ion Surface Technology have found so far that the market for nitrogen implantation is limited. Both market and technical barriers exist to more widespread acceptance in industry. Market factors include cost, industrial conservatism, and production priorities in manufacturing. Technical factors include the size of available implanters, the line-of-sight limitation of ion implantation, sputtering, and other process limitations such as shallow penetration depth. Several recent technical developments that should greatly increase market acceptance are described: 1. large-scale nitrogen implanters, 2. the non-line-of-sight plasma source ion implantation process, and 3. ion assisted coating techniques. (orig.)

The Influence of the Intermediary System of Cognition on Vocabulary Acquisition for Chinese English-Majors

Science.gov (United States)

Luo, Yanyan

2009-01-01

In the article, the author tries to find out the main factors that affect the subject's vocabulary acquisition by an investigation. It is concluded that vocabulary acquisition models and strategies are something external, what really works upon vocabulary acquisition is the intermediary system of cognition including the knowledge structure and…

Labour Market Intermediaries: A Corrective to the Human Capital Paradigm (Mis)matching Skills and Jobs?

Science.gov (United States)

Dobbins, Tony; Plows, Alexandra

2017-01-01

The orthodox supply-side human capital theory (HCT) paradigm is inadequate for understanding and adjusting to labour market volatility in UK regional economies like Wales. This article explores the role of regional labour market intermediaries (LMIs) in matching supply (skills) and demand (job opportunities) in regional labour markets. Some LMIs…

Radioactive wastes: underground laboratories implantation

International Nuclear Information System (INIS)

Bataille, Ch.

1997-01-01

This article studies the situation of radioactive waste management, more especially the possible storage in deep laboratories. In front of the reaction of public opinion relative to the nuclear waste question, it was essential to begin by a study on the notions of liability, transparence and democracy. At the beginning, it was a matter of underground researches with a view to doing an eventual storage of high level radioactive wastes. The Parliament had to define, through the law, a behaviour able to come to the fore for anybody. A behaviour which won recognition from authorities, from scientists, from industrial people, which guarantees the rights of populations confronted to a problem whom they were not informed, on which they received only few explanations. (N.C.)

Tolerance measurements on internal- and external-hexagon implants.

Science.gov (United States)

Braian, Michael; De Bruyn, Hugo; Fransson, Håkan; Christersson, Cecilia; Wennerberg, Ann

2014-01-01

To measure the horizontal machining tolerances of the interface between internal- and external-hexagon implants and analogs with corresponding components after delivery from the manufacturer. These values may be a valuable tool for evaluating increasing misfit caused by fabrication, processing, and wear. Seven implants and seven analogs with external- and internal-hexagon connections (Biomet 3i) with corresponding prefabricated gold cylinders and gold screws, prefabricated cylindric plastic cylinders, and laboratory screws were studied. One set of components from the external and internal groups was measured manually and digitally. Measurements from the test subjects were compared with identical measurements from the virtual model to obtain threshold values. The virtual model was then used to obtain optimally oriented cuts. The horizontal machining tolerances for castable plastic abutments on external implants were 12 ± 89 μm, and for internal implants they were 86 ± 47 μm. Tolerance measurements on prefabricated gold abutments for external implants were 44 ± 9 μm, and for internal implants they were 58 ± 28 μm. The groups with metallic components showed the smallest tolerance at external group and internal group. The prefabricated plastic cylinder groups ranged from external and internal connection.

Qualitative and quantitative observations of bone tissue reactions to anodised implants.

Science.gov (United States)

Sul, Young-Taeg; Johansson, Carina B; Röser, Kerstin; Albrektsson, Tomas

2002-04-01

Research projects focusing on biomaterials related factors; the bulk implant material, the macro-design of the implant and the microsurface roughness are routinely being conducted at our laboratories. In this study, we have investigated the bone tissue reactions to turned commercially pure (c.p.) titanium implants with various thicknesses of the oxide films after 6 weeks of insertion in rabbit bone. The control c.p. titanium implants had an oxide thickness of 17-200 nm while the test implants revealed an oxide thickness between 600 and 1000 nm. Routine histological investigations of the tissue reactions around the implants and enzyme histochemical detections of alkaline and acid phosphatase activities demonstrated similar findings around both the control and test implants. In general, the histomorphometrical parameters (bone to implant contact and newly formed bone) revealed significant quantitative differences between the control and test implants. The test implants demonstrated a greater bone response histomorphometrically than control implants and the osteoconductivity was more pronounced around the test implant surfaces. The parameters that differed between the implant surfaces, i.e. the oxide thickness, the pore size distribution, the porosity and the crystallinity of the surface oxides may represent factors that have an influence on the histomorphometrical results indicated by a stronger bone tissue response to the test implant surfaces, with an oxide thickness of more than 600 nm.

Implanted telemeter for electrocardiogram and body temperature

Science.gov (United States)

Barrows, W. F.

1972-01-01

Measuring system requiring one blocking oscillator to generate modulated pulse repetition rate is implantable in the bodies of small animals. Device has life of two years and transmission range of about three feet. EKG sensing unit also is used to sense electromyogram or electrooculogram of laboratory animals.

13 CFR 120.1425 - Grounds for enforcement actions-Intermediaries participating in the Microloan Program and NTAPs.

Science.gov (United States)

2010-01-01

... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Grounds for enforcement actions-Intermediaries participating in the Microloan Program and NTAPs. 120.1425 Section 120.1425 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION BUSINESS LOANS Risk-Based Lender Oversight Enforcement Actions § 120...

13 CFR 120.1540 - Types of enforcement actions-Intermediaries participating in the Microloan Program and NTAPs.

Science.gov (United States)

2010-01-01

... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Types of enforcement actions-Intermediaries participating in the Microloan Program and NTAPs. 120.1540 Section 120.1540 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION BUSINESS LOANS Risk-Based Lender Oversight Enforcement Actions § 120...

Implant-bone boundary, management with coordinative of zinc and vanadium compounds

International Nuclear Information System (INIS)

Granciuc, Victoria; Manascurta, Ghenadie; Granciuc, Gheorge

2013-01-01

Theoretical concept about description of the implant integration into the bone on a microscopic view remains to be a wide studied subject. The study of the morphological samples with sections on the border implant-bone had been done on different depths and sides of the implant using hematoxylin-eosin stain. Remarkable result had been observed on comparative analysis of studied groups on administrating TS-2Z and TS-1Z,TS-9V that did stimulate bone regeneration. Histological studies confirm the results of improvement of biochemical and blood indexes after implant surgery at the laboratory animals that had received coordinative compounds of Zn(L-H)2; Zn(L-H)etazol; [Vo(L- H)etazol]2SO4. (authors)

Bone integration capability of nanopolymorphic crystalline hydroxyapatite coated on titanium implants

OpenAIRE

Ogawa, Takahiro; Yamada,Masahiro; Ueno,; Tsukimura,Naoki; Ikeda,; Nakagawa,; Hori,; Suzuki,

2012-01-01

Masahiro Yamada*, Takeshi Ueno*, Naoki Tsukimura, Takayuki Ikeda, Kaori Nakagawa, Norio Hori, Takeo Suzuki, Takahiro OgawaLaboratory of Bone and Implant Sciences, The Weintraub Center for Reconstructive Biotechnology, Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, UCLA School of Dentistry, Los Angeles, CA, USA *These authors contributed equally to this workAbstract: The mechanism by which hydroxyapatite (HA)-coated titanium promotes bone–implant integratio...

Implant-assisted removable partial dentures: practical considerations.

Science.gov (United States)

Omura, Aaron J; Latthe, Vaibhav; Marin, Mark M; Cagna, David R

2016-01-01

At the heart of prosthodontic treatment planning must be a sound understanding of the quality and reliability of the prosthodontic foundation. Implant prosthodontics relies almost entirely on the biological and mechanical properties of an osseous foundation. Initiation of therapy in the absence of a healthy and stable prosthodontic foundation risks unintended and suboptimal treatment outcomes. For conventional removable partial denture (RPD) therapy, consideration must be given to interactions between the soft and hard tissues available to support and stabilize planned prostheses. The strategic addition of implants to the partially edentulous foundation can improve the support, comfort, and esthetics of an RPD, resulting in elevated patient satisfaction and greater therapeutic success. This article discusses aspects of diagnosis, treatment planning, clinical management, laboratory execution, and maintenance that must be considered in order to obtain optimal results with implant-assisted RPDs.

The fabrication of bioresorbable implants for bone defects replacement using computer tomogram and 3D printing

Science.gov (United States)

Kuznetsov, P. G.; Tverdokhlebov, S. I.; Goreninskii, S. I.; Bolbasov, E. N.; Popkov, A. V.; Kulbakin, D. E.; Grigoryev, E. G.; Cherdyntseva, N. V.; Choinzonov, E. L.

2017-09-01

The present work demonstrates the possibility of production of personalized implants from bioresorbable polymers designed for replacement of bone defects. The stages of creating a personalized implant are described, which include the obtaining of 3D model from a computer tomogram, development of the model with respect to shape of bone fitment bore using Autodesk Meshmixer software, and 3D printing process from bioresorbable polymers. The results of bioresorbable polymer scaffolds implantation in pre-clinical tests on laboratory animals are shown. The biological properties of new bioresorbable polymers based on poly(lactic acid) were studied during their subcutaneous, intramuscular, bone and intraosseous implantation in laboratory animals. In all cases, there was a lack of a fibrous capsule formation around the bioresorbable polymer over time. Also, during the performed study, conclusions were made on osteogenesis intensity depending on the initial state of bone tissue.

Information Technology and Aerospace Knowledge Diffusion: Exploring the Intermediary-End User Interface in a Policy Framework.

Science.gov (United States)

Pinelli, Thomas E.; And Others

1992-01-01

Discusses U.S. technology policy and the transfer of scientific and technical information (STI). Results of a study of knowledge diffusion in the aerospace industry are reported, including data on aerospace information intermediaries, use of computer and information technologies, and the use of NASA (National Aeronautics and Space Administration)…

Providing Spark and Stability: The Role of Intermediary Organizations in Establishing School-Based Youth-Adult Partnerships

Science.gov (United States)

Mitra, Dana L.; Sanders, Felicia C.; Perkins, Daniel F.

2010-01-01

The term "youth-adult partnership" increasingly is being used to define a relationship in which both youth and adults have the potential to contribute to decision making processes, to learn from one another, and to promote change. Establishing a relationship with an "intermediary organization" can provide much needed stability and sustainability…

Short Implants: New Horizon in Implant Dentistry.

Science.gov (United States)

Jain, Neha; Gulati, Manisha; Garg, Meenu; Pathak, Chetan

2016-09-01

The choice of implant length is an essential factor in deciding the survival rates of these implants and the overall success of the prosthesis. Placing an implant in the posterior part of the maxilla and mandible has always been very critical due to poor bone quality and quantity. Long implants can be placed in association with complex surgical procedures such as sinus lift and bone augmentation. These techniques are associated with higher cost, increased treatment time and greater morbidity. Hence, there is need for a less invasive treatment option in areas of poor bone quantity and quality. Data related to survival rates of short implants, their design and prosthetic considerations has been compiled and structured in this manuscript with emphasis on the indications, advantages of short implants and critical biomechanical factors to be taken into consideration when choosing to place them. Studies have shown that comparable success rates can be achieved with short implants as those with long implants by decreasing the lateral forces to the prosthesis, eliminating cantilevers, increasing implant surface area and improving implant to abutment connection. Short implants can be considered as an effective treatment alternative in resorbed ridges. Short implants can be considered as a viable treatment option in atrophic ridge cases in order to avoid complex surgical procedures required to place long implants. With improvement in the implant surface geometry and surface texture, there is an increase in the bone implant contact area which provides a good primary stability during osseo-integration.

Transposition of the Mortgage Credit Directive into Hungarian and Czech law – The Problem of Credit Intermediaries

Czech Academy of Sciences Publication Activity Database

Simon, Rita

2017-01-01

Roč. 6, č. 3 (2017), s. 106-112 ISSN 2364-4710 Institutional support: RVO:68378122 Keywords : mortgage credit directive * consumer protection * credit intermediaries Subject RIV: AG - Legal Sciences OBOR OECD: Law https://www.kluwerlawonline.com/abstract.php?area=Journals&id=EuCML2017025

Influence of Palatal Coverage and Implant Distribution on Implant Strain in Maxillary Implant Overdentures.

Science.gov (United States)

Takahashi, Toshihito; Gonda, Tomoya; Mizuno, Yoko; Fujinami, Yozo; Maeda, Yoshinobu

2016-01-01

Maxillary implant overdentures are often used in clinical practice. However, there is no agreement or established guidelines regarding prosthetic design or optimal implant placement configuration. The purpose of this study was to examine the influence of palatal coverage and implant number and distribution in relation to impact strain under maxillary implant overdentures. A maxillary edentulous model with implants and experimental overdentures with and without palatal coverage was fabricated. Four strain gauges were attached to each implant, and they were positioned in the anterior, premolar, and molar areas. A vertical occlusal load of 98 N was applied through a mandibular complete denture, and the implant strains were compared using one-way analysis of variance (P = .05). The palatolabial strain was much higher on anterior implants than on other implants in both denture types. Although there was no significant difference between the strain under dentures with and without palatal coverage, palateless dentures tended to result in higher implant strain than dentures with palatal coverage. Dentures supported by only two implants registered higher strain than those supported by four or six implants. Implants under palateless dentures registered higher strain than those under dentures with palatal coverage. Anterior implants exhibited higher palatolabial strain than other implants regardless of palatal coverage and implant configuration; it is therefore recommended that maxillary implant overdentures should be supported by six implants with support extending to the distal end of the arch.

Nitrogen implantation with a scanning electron microscope.

Science.gov (United States)

Becker, S; Raatz, N; Jankuhn, St; John, R; Meijer, J

2018-01-08

Established techniques for ion implantation rely on technically advanced and costly machines like particle accelerators that only few research groups possess. We report here about a new and surprisingly simple ion implantation method that is based upon a widespread laboratory instrument: The scanning electron microscope. We show that it can be utilized to ionize atoms and molecules from the restgas by collisions with electrons of the beam and subsequently accelerate and implant them into an insulating sample by the effect of a potential building up at the sample surface. Our method is demonstrated by the implantation of nitrogen ions into diamond and their subsequent conversion to nitrogen vacancy centres which can be easily measured by fluorescence confocal microscopy. To provide evidence that the observed centres are truly generated in the way we describe, we supplied a 98% isotopically enriched 15 N gas to the chamber, whose natural abundance is very low. By employing the method of optically detected magnetic resonance, we were thus able to verify that the investigated centres are actually created from the 15 N isotopes. We also show that this method is compatible with lithography techniques using e-beam resist, as demonstrated by the implantation of lines using PMMA.

Hybrid Donor-Dot Devices made using Top-down Ion Implantation for Quantum Computing

Science.gov (United States)

Bielejec, Edward; Bishop, Nathan; Carroll, Malcolm

2012-02-01

We present progress towards fabricating hybrid donor -- quantum dots (QD) for quantum computing. These devices will exploit the long coherence time of the donor system and the surface state manipulation associated with a QD. Fabrication requires detection of single ions implanted with 10's of nanometer precision. We show in this talk, 100% detection efficiency for single ions using a single ion Geiger mode avalanche (SIGMA) detector integrated into a Si MOS QD process flow. The NanoImplanter (nI) a focused ion beam system is used for precision top-down placement of the implanted ion. This machine has a 10 nm resolution combined with a mass velocity filter, allowing for the use of multi-species liquid metal ion sources (LMIS) to implant P and Sb ions, and a fast blanking and chopping system for single ion implants. The combination of the nI and integration of the SIGMA with the MOS QD process flow establishes a path to fabricate hybrid single donor-dot devices. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Knowledge Brokers in Education: How Intermediary Organizations Are Bridging the Gap between Research, Policy and Practice Internationally

Science.gov (United States)

Cooper, Amanda; Shewchuk, Samantha

2015-01-01

Interest in how to better connect research to policy and practice is gaining momentum globally. Also gaining widespread agreement is the view that intermediary organizations have an important role to play in facilitating multi-stakeholder partnerships between researchers, practitioners and policymakers in order to increase the mobilization of…

Trade associations and labor organizations as intermediaries for disseminating workplace safety and health information.

Science.gov (United States)

Okun, Andrea H; Watkins, Janice P; Schulte, Paul A

2017-09-01

There has not been a systematic study of the nature and extent to which business and professional trade associations and labor organizations obtain and communicate workplace safety and health information to their members. These organizations can serve as important intermediaries and play a central role in transferring this information to their members. A sample of 2294 business and professional trade associations and labor organizations in eight industrial sectors identified by the National Occupational Research Agenda was surveyed via telephone. A small percent of these organizations (40.9% of labor organizations, 15.6% of business associations, and 9.6% of professional associations) were shown to distribute workplace safety and health information to their members. Large differences were also observed between industrial sectors with construction having the highest total percent of organizations disseminating workplace safety and health information. There appears to be significant potential to utilize trade and labor organizations as intermediaries for transferring workplace safety and health information to their members. Government agencies have a unique opportunity to partner with these organizations and to utilize their existing communication channels to address high risk workplace safety and health concerns. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

The effect of ion implantation on the fatigue behavior of metals and alloys

International Nuclear Information System (INIS)

Chakrabortty, S.B.; Kujore, A.; Legg, K.O.; Starke, E.A.

1981-01-01

The effect of ion implantation on the strain and stress controlled fatigue behavior of polycrystalline copper has been investigated. The cyclic stress-strain response, strain-life and stress-life relationships and fatigue crack nucleation behavior have been studied. The results from the non-implanted materials have been compared with those from the implanted materials. Four implant species, one with a positive misfit, one with a negative misfit, one with a zero misfit, and one insoluble under equilibrium conditions have been used. Most of the fatigue tests were performed in laboratory air. Ion implantation changes the surface deformation behavior for both monotonic and cyclic loading with a corresponding change in hardening rate. Larger changes are observed for the cyclic loading. Implantations which lead to a more homogeneous deformation (fine slip) near the surface, improves the resistance to fatigue crack initiation. Surface compressive residual stresses, induced from implanting a positive misfit species, have a major influence on crack initiation in the stress-life regime

A software tool for analyzing multichannel cochlear implant signals.

Science.gov (United States)

Lai, Wai Kong; Bögli, Hans; Dillier, Norbert

2003-10-01

A useful and convenient means to analyze the radio frequency (RF) signals being sent by a speech processor to a cochlear implant would be to actually capture and display them with appropriate software. This is particularly useful for development or diagnostic purposes. sCILab (Swiss Cochlear Implant Laboratory) is such a PC-based software tool intended for the Nucleus family of Multichannel Cochlear Implants. Its graphical user interface provides a convenient and intuitive means for visualizing and analyzing the signals encoding speech information. Both numerical and graphic displays are available for detailed examination of the captured CI signals, as well as an acoustic simulation of these CI signals. sCILab has been used in the design and verification of new speech coding strategies, and has also been applied as an analytical tool in studies of how different parameter settings of existing speech coding strategies affect speech perception. As a diagnostic tool, it is also useful for troubleshooting problems with the external equipment of the cochlear implant systems.

Study of the physical phenomena in the transformation of the in vivo implanted coral, using radioactivation techniques, by means of X-ray diffraction and infrared spectrometry

International Nuclear Information System (INIS)

Oudadesse, H.

1989-01-01

By radioactivation analysis, we measured quantitatively for the first time the elementary transformation of coral in vivo. Some natural coral was implanted after having been sterilized in ovine jaws. Every month, biopsies were extracted in order to get a portion of the external cortical part, the intermediary part (initially the coral) and the internal cortical part. We measured the kinetics of the concentration of major atomic elements which constitute the biological mould such as phosphorus, calcium, magnesium, fluorine, as well as strontium of which content was abundantly found in the coral. The results show intense disturbances until the fifth month, when the mineral structure of the implanted coral becomes akin to that of bone come to maturity. In addition, with measures by diffraction by X-ray, we have followed the structural modifications by relating them to the variation in concentration of atomic elements. The coral, in the form of aragonit and stabilized by strontium as shown by neutron radioactivation crystallises in an orthorombic system. Three months after having been implanted, its structure becomes hexagonal and reaches a degree of crystallization similar to that of a bone come to maturity about the fifth month. The infrared absorption spectroscopy allowed us to fine the structure by specifying the mineral of the bone and of the implanted coral. Three months after having been implanted, the coral has become an apatite with deposit of organic substances. Moreover, a calcination at high temperature revealed a supply of phosphorus ions from the first month until the fifth month [fr

Toward the extension of obligations to other intermediaries in the internet

Directory of Open Access Journals (Sweden)

Ernesto Rengifo García

2014-12-01

Full Text Available It is well known that the copy diminishes the individual value of the creation and discourages the effort of the creator. Because of this, the responsibility of internet service providers (ISP concerning copyright infringement by their users has been a subject of great controversy for more than a decade. This discussion has led to a consensus in the sense that the ISP will not be responsible when their participation in the infringement is limited to transmitting, linking, caching, and disseminating information generated by third parties, as long as other requirements are met, such as adopting and communicating policies intended to prevent infringements. However, the development of new business models and the expansion of services available online have raised the question of whether it is possible to extend the secondary or indirect liability regime to other intermediaries such as internet advertising services and financial transaction providers. In order to analyze the liability regimes that could be applied to these intermediaries,¡ it is important to take into account the following points, which will be developed in this paper: i to understand the operation of online advertising and payments and the economic magnitude of these businesses, ii to understand the liability regime presently applied to the isp, iii to study the objections that have been raised against the extension of such regime to online advertising and financial transaction providers, and finally, iv to analyze how through recent legislative initiatives such as the proposed PIPA, SOPA, and open bills in the United States, efforts have been undertaken to overcome the objections and to offer effective and expeditious mechanisms to protect copyright in the internet.

Expansão rápida da maxila ancorada em implantes: uma nova proposta para expansão ortopédica na dentadura permanente Rapid maxillary expansion anchored by implants: a new proposal to orthopedic expansion in the permanent dentition

Directory of Open Access Journals (Sweden)

Daniela Gamba Garib

2007-06-01

Full Text Available OBJETIVO: este trabalho apresenta um método para expansão ortopédica da maxila, na dentadura permanente, utilizando implantes como ancoragem. METODOLOGIA: detalharam-se os procedimentos cirúrgicos e laboratoriais da confecção de um expansor com ancoragem dento-óssea em crânio seco humano. Dois implantes de titânio foram colocados na região anterior do palato, e o parafuso Hyrax adaptado de modo que a expansão ancorou-se nos implantes e nos primeiros molares permanentes. RESULTADOS: o experimento laboratorial em crânio seco mostrou que o procedimento apresenta-se anatômica e operacionalmente viável. Os implantes suportaram a força gerada pela ativação do parafuso expansor, redundando na separação transversal das hemimaxilas. CONCLUSÕES: vislumbra-se que a expansão rápida da maxila ancorada em implantes (ERMAI poderá potencializar a eficiência da expansão ortopédica, assim como reduzir o custo periodontal dos procedimentos convencionais de expansão. Futuros estudos clínicos são necessários para testar essas hipóteses.AIM: This study presents a method for maxillary orthopedic expansion, in the permanent dentition, using implants as anchorage. METHODS: Surgical and laboratorial procedures for the construction of a tooth-bone-borne expansor was detailed in a human dry skull. Two titanium implants were placed in the anterior region of the palate and a Hyrax screw was adapted in a way that the expansion was anchored both on the palatal implants and on permanent first molars. RESULTS: The laboratorial experiment in dry skull showed that the procedure is operationally and anatomically possible. The implants supported the force generated by the expansion screw activation and the maxilla halves were transversally split. CONCLUSIONS: Rapid maxillary expansion anchored on implants can increase the efficiency of orthopedic expansion and decrease the periodontal sequela caused by conventional RME. Further clinical studies are

Performance of community health workers:situating their intermediary position within complex adaptive health systems

OpenAIRE

Kok, Maryse. C; Broerse, Jacqueline E.W; Theobald, Sally; Ormel, Hermen; Dieleman, Marjolein; Taegtmeyer, Miriam

2017-01-01

Health systems are social institutions, in which health worker performance is shaped by transactional processes between different actors. This analytical assessment unravels the complex web of factors that influence the performance of community health workers (CHWs) in low- and middle-income countries. It examines their unique intermediary position between the communities they serve and actors in the health sector, and the complexity of the health systems in which they operate. The assessment...

Utilizing a Rat Delayed Implantation Model to Teach Integrative Endocrinology and Reproductive Biology

Science.gov (United States)

Geisert, Rodney D.; Smith, Michael F.; Schmelzle, Amanda L.; Green, Jonathan A.

2018-01-01

In this teaching laboratory, the students are directed in an exercise that involves designing and performing an experiment to determine estrogen's role in regulating delayed implantation (diapause) in female rats. To encourage active participation by the students, a discussion question is provided before the laboratory exercise in which each…

Anesthesia management for MitraClip device implantation

Directory of Open Access Journals (Sweden)

Harikrishnan Kothandan

2014-01-01

Full Text Available Aims and Objectives: Percutaneous MitraClip implantation has been demonstrated as an alternative procedure in high-risk patients with symptomatic severe mitral regurgitation (MR who are not suitable (or denied mitral valve repair/replacement due to excessive co morbidity. The MitraClip implantation was performed under general anesthesia and with 3-dimensional transesophageal echocardiography (TEE and fluoroscopic guidance. Materials and Methods: Peri-operative patient data were extracted from the electronic and paper medical records of 21 patients who underwent MitraClip implantations. Results: Four MitraClip implantation were performed in the catheterization laboratory; remaining 17 were performed in the hybrid operating theatre. In 2 patients, procedure was aborted, in one due to migration of the Chiari network into the left atrium and in second one, the leaflets and chords of the mitral valve torn during clipping resulting in consideration for open surgery. In the remaining 19 patients, MitraClip was implanted and the patients showed acute reduction of severe MR to mild-moderate MR. All the patients had invasive blood pressure monitoring and the initial six patients had central venous catheterization prior to the procedure. Intravenous heparin was administered after the guiding catheter was introduced through the inter-atrial septum and activated clotting time was maintained beyond 250 s throughout the procedure. Protamine was administered at the end of the procedure. All the patients were monitored in the intensive care unit after the procedure. Conclusions: Percutaneous MitraClip implantation is a feasible alternative in high-risk patients with symptomatic severe MR. Anesthesia management requirements are similar to open surgical mitral valve repair or replacement. TEE plays a vital role during the MitraClip implantation.

Monte Carlo simulation of boron-ion implantation into single-crystal silicon

International Nuclear Information System (INIS)

Klein, K.M.

1991-01-01

A physically based Monte Carlo boron implantation model developed comprehends previously neglected but important implant parameters such as native oxide layers, wafer temperature, beam divergence, tilt angle, rotation (twist) angle, and dose, in addition to energy. This model uses as its foundation the MARLOWE Monte Carlo simulation code developed at Oak Ridge National Laboratory for the analysis of radiation effects in materials. This code was carefully adapted for the simulation of ion implantation, and a number of significant improvements have been made, including the addition of atomic pair specific interatomic potentials, the implementation of a newly developed local electron concentration dependent electronic stopping model, and the implementation of a newly developed cumulative damage model. This improved version of the code, known as UT-MARLOWE, allows boron implantation profiles to be accurately predicted as a function of energy, tilt angle, rotation angle, and dose. This code has also been used in the development and implementation of an accurate and efficient two-dimensional boron implantation model

A Simplified Technique for Implant-Abutment Level Impression after Soft Tissue Adaptation around Provisional Restoration

Science.gov (United States)

Kutkut, Ahmad; Abu-Hammad, Osama; Frazer, Robert

2016-01-01

Impression techniques for implant restorations can be implant level or abutment level impressions with open tray or closed tray techniques. Conventional implant-abutment level impression techniques are predictable for maximizing esthetic outcomes. Restoration of the implant traditionally requires the use of the metal or plastic impression copings, analogs, and laboratory components. Simplifying the dental implant restoration by reducing armamentarium through incorporating conventional techniques used daily for crowns and bridges will allow more general dentists to restore implants in their practices. The demonstrated technique is useful when modifications to implant abutments are required to correct the angulation of malpositioned implants. This technique utilizes conventional crown and bridge impression techniques. As an added benefit, it reduces costs by utilizing techniques used daily for crowns and bridges. The aim of this report is to describe a simplified conventional impression technique for custom abutments and modified prefabricated solid abutments for definitive restorations. PMID:29563457

A Simplified Technique for Implant-Abutment Level Impression after Soft Tissue Adaptation around Provisional Restoration

Directory of Open Access Journals (Sweden)

Ahmad Kutkut

2016-05-01

Full Text Available Impression techniques for implant restorations can be implant level or abutment level impressions with open tray or closed tray techniques. Conventional implant-abutment level impression techniques are predictable for maximizing esthetic outcomes. Restoration of the implant traditionally requires the use of the metal or plastic impression copings, analogs, and laboratory components. Simplifying the dental implant restoration by reducing armamentarium through incorporating conventional techniques used daily for crowns and bridges will allow more general dentists to restore implants in their practices. The demonstrated technique is useful when modifications to implant abutments are required to correct the angulation of malpositioned implants. This technique utilizes conventional crown and bridge impression techniques. As an added benefit, it reduces costs by utilizing techniques used daily for crowns and bridges. The aim of this report is to describe a simplified conventional impression technique for custom abutments and modified prefabricated solid abutments for definitive restorations.

Few electron quantum dot coupling to donor implanted electron spins

Science.gov (United States)

Rudolph, Martin; Harvey-Collard, Patrick; Neilson, Erik; Gamble, John; Muller, Richard; Jacobson, Toby; Ten-Eyck, Greg; Wendt, Joel; Pluym, Tammy; Lilly, Michael; Carroll, Malcolm

2015-03-01

Donor-based Si qubits are receiving increased interest because of recent demonstrations of high fidelity electron or nuclear spin qubits and their coupling. Quantum dot (QD) mediated interactions between donors are of interest for future coupling of two donors. We present experiment and modeling of a polysilicon/Si MOS QD, charge-sensed by a neighboring many electron QD, capable of coupling to one or two donor implanted electron spins (D) while tuned to the few electron regime. The unique design employs two neighboring gated wire FETs and self-aligned implants, which supports many configurations of implanted donors. We can access the (0,1) ⇔(1,0) transition between the D and QD, as well as the resonance condition between the few electron QD and two donors ((0,N,1) ⇔(0,N +1,0) ⇔(1,N,0)). We characterize capacitances and tunnel rate behavior combined with semi-classical and full configuration interaction simulations to study the energy landscape and kinetics of D-QD transitions. This work was performed, in part, at the Center for Integrated Nanotechnologies, a U.S. DOE, Office of Basic Energy Sciences user facility. The work was supported by the Sandia National Laboratories Directed Research and Development Program. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a Lockheed-Martin Company, for the U. S. Department of Energy under Contract No. DE-AC04-94AL85000.

Conception of CTMSP ionizing radiation calibration laboratory

International Nuclear Information System (INIS)

Silva, Raimundo Dias da; Kibrit, Eduardo

2009-01-01

The present paper describes the implantation process of an ionizing radiation calibration laboratory in a preexistent installation in CTMSP (bunker) approved by CNEN to operate with gamma-ray for non destructive testing. This laboratory will extend and improve the current metrological capacity for the attendance to the increasing demand for services of calibration of ionizing radiation measuring instruments. Statutory and regulatory requirements for the licensing of the installation are presented and deeply reviewed. (author)

Ion implantation

International Nuclear Information System (INIS)

Dearnaley, Geoffrey

1975-01-01

First, ion implantation in semiconductors is discussed: ion penetration, annealing of damage, gettering, ion implanted semiconductor devices, equipement requirements for ion implantation. The importance of channeling for ion implantation is studied. Then, some applications of ion implantation in metals are presented: study of the corrosion of metals and alloys; influence or ion implantation on the surface-friction and wear properties of metals; hyperfine interactions in implanted metals

Intermediation in Foreign Trade: When do Exporters Rely on Intermediaries?

DEFF Research Database (Denmark)

Schröder, Philipp; Trabold, Harald; Trübswetter, Parvati

2003-01-01

The paper explores theoretically and empirically why trade intermediaries (TIs) are frequently used as agents for exports to some countries but not to others. We adapt a standard intra-industry trade model with variable export costs (e.g. transport) and fixed export costs (e.g. market access......) to include a TI that is able to pool market access cost. From this framework explanatory factors for the TI share in a country's exports are derived and subsequently tested with a new data set based on French customs information. The paper finds that: (i) higher market access costs increase the TI share, (ii......) smaller export markets feature a larger TI share, (iii) the TI share is independent from variable (distance-dependent) export costs....

Hotels’ dependency on online intermediaries and their chosen distribution channel portfolios: three country insights

OpenAIRE

Stangl, Brigitte; Inversini, Alessandro; Schegg, Roland

2016-01-01

New intermediaries are entering the market, challenging the hospitality industry to find an appropriate\\ud distribution channel portfolio. This research investigates how many channels hotels in Austria, Germany\\ud and Switzerland choose and what role the various channels play. Findings based on 1014 questionnaires\\ud reveal an average mix of 8.06 offline and online channel categories. Traditional channels, such as walk-ins\\ud and telephone, still play a major role; however, about one fifth of...

Exploring the Roles of Intermediaries in Collective Memory-Supported Electronic Negotiation: A Theoretical Framework

OpenAIRE

Nongkran Lertpittayapoom; Souren Paul

2006-01-01

Following the emergence of the Internet, electronic negotiation has become an alternative to face-to-face negotiation. The current forms of negotiation support systems (NSS) used to support many electronic negotiations offer very little support for historical negotiation data. In order to address this issue, the idea of a collective memory support in negotiations has been proposed in recent years. This article highlights the use of an online intermediary as an effective location from which co...

Clinical and microbiological characteristics of peri-implantitis cases: a retrospective multicentre study.

Science.gov (United States)

Charalampakis, G; Leonhardt, Å; Rabe, P; Dahlén, G

2012-09-01

The aim of this study was to follow patient cases retrospectively in a longitudinal manner from the time of implant placement to the time they were diagnosed with peri-implant disease, and to identify associated clinical and microbiological features of peri-implant disease. A total of 281 patient cases were chosen from the archives of the Oral Microbiological Diagnostic Laboratory, Gothenburg, Sweden, based on bacterial samples taken from diseased implants. A form was designed and filled in separately for each case including data on patient, implant and disease profile. Most cases were severe peri-implantitis cases (91.4%). In 41.3% of the patients, peri-implantitis was developed early, already after having implants in function less than 4 years. The type of implant surface was significantly associated with the time in years implants were in function, before disease was developed (P < 0.05). The microbiological results by both culture and checkerboard analysis, although failed to fully correspond to the severity of the disease in terms of magnitude, proved to show that peri-implantitis is a polymicrobial anaerobic infection with increased number of AGNB (aerobic Gram-negative bacilli) in 18.6% of the patients. Peri-implantitis is a biological complication of implants in function that poses a threat to their long-term survival. It may develop earlier around implants with rough surfaces and it may represent a true infection. Microbiological sampling methods should be improved and uniformed so as to fully unveil the microbiological profile of the disease. © 2011 John Wiley & Sons A/S.

[Retrieval and failure analysis of surgical implants in Brazil: the need for proper regulation].

Science.gov (United States)

Azevedo, Cesar R de Farias; Hippert, Eduardo

2002-01-01

This paper summarizes several cases of metallurgical failure analysis of surgical implants conducted at the Laboratory of Failure Analysis, Instituto de Pesquisas Tecnológicas (IPT), in Brazil. Failures with two stainless steel femoral compression plates, one stainless steel femoral nail plate, one Ti-6Al-4V alloy maxillary reconstruction plate, and five Nitinol wires were investigated. The results showed that the implants were not in accordance with ISO standards and presented evidence of corrosion-assisted fracture. Furthermore, some of the implants presented manufacturing/processing defects which also contributed to their premature failure. Implantation of materials that are not biocompatible may cause several types of adverse effects in the human body and lead to premature implant failure. A review of prevailing health legislation is needed in Brazil, along with the adoption of regulatory mechanisms to assure the quality of surgical implants on the market, providing for compulsory procedures in the reporting and investigation of surgical implants which have failed in service.

A biometric approach to laboratory rodent identification.

Science.gov (United States)

Cameron, Jens; Jacobson, Christina; Nilsson, Kenneth; Rögnvaldsson, Thorsteinn

2007-03-01

Individual identification of laboratory rodents typically involves invasive methods, such as tattoos, ear clips, and implanted transponders. Beyond the ethical dilemmas they may present, these methods may cause pain or distress that confounds research results. The authors describe a prototype device for biometric identification of laboratory rodents that would allow researchers to identify rodents without the complications of other methods. The device, which uses the rodent's ear blood vessel pattern as the identifier, is fast, automatic, noninvasive, and painless.

Low energy implantation of boron with decaborane ions

Science.gov (United States)

Albano, Maria Angela

The goal of this dissertation was to determine the feasibility of a novel approach to forming ultra shallow p-type junctions (tens of nm) needed for future generations of Si MOS devices. In the new approach, B dopant atoms are implanted by cluster ions obtained by ionization of decaborane (B 10H14) vapor. An experimental ion implanter with an electron impact ion source and magnetic mass separation was built at the Ion Beam and Thin Film Research Laboratory at NJIT. Beams of B10Hx+ ions with currents of a few microamperes and energies of 1 to 12 keV were obtained and used for implantation experiments. Profiles of B and H atoms implanted in Si were measured by Secondary Ion Mass Spectroscopy (SIMS) before and after rapid thermal annealing (RTA). From the profiles, the junction depth of 57 nm (at 1018 cm-3 B concentration) was obtained with 12 keV decaborane ions followed by RTA. The dose of B atoms that can be implanted at low energy into Si is limited by sputtering as the ion beam sputters both the matrix and the implanted atoms. As the number of sputtered B atoms increases with the implanted dose and approaches the number of the implanted atoms, equilibrium of B in Si is established. This effect was investigated by comparison of the B dose calculated from the ion beam integration with B content in the sample measured by Nuclear Reaction Analysis (NRA). Maximum (equilibrium) doses of 1.35 x 1016 B cm -2 and 2.67 x 1016 B cm-2 were obtained at the beam energies of 5 and 12 keV, respectively. The problem of forming shallow p-type junctions in Si is related not only to implantation depth, but also to transient enhanced diffusion (TED). TED in Si implanted with B10Hx+ was measured on boron doping superlattice (B-DSL) marker layers. It was found that TED, following decaborane implantation, is the same as with monomer B+ ion implantation of equivalent energy and that it decreases with the decreasing ion energy. (Abstract shortened by UMI.)

The laboratories of geological studies

International Nuclear Information System (INIS)

1994-01-01

This educational document comprises 4 booklets in a folder devoted to the presentation of the ANDRA's activities in geological research laboratories. The first booklet gives a presentation of the missions of the ANDRA (the French agency for the management of radioactive wastes) in the management of long life radioactive wastes. The second booklet describes the approach of waste disposal facilities implantation. The third booklet gives a brief presentation of the scientific program concerning the underground geologic laboratories. The last booklet is a compilation of questions and answers about long-life radioactive wastes, the research and works carried out in geologic laboratories, the public information and the local socio-economic impact, and the storage of radioactive wastes in deep geological formations. (J.S.)

Axial displacement of abutments into implants and implant replicas, with the tapered cone-screw internal connection, as a function of tightening torque.

Science.gov (United States)

Dailey, Bruno; Jordan, Laurence; Blind, Olivier; Tavernier, Bruno

2009-01-01

The passive fit of a superstructure on implant abutments is essential to success. One source of error when using a tapered cone-screw internal connection may be the difference between the tightening torque level applied to the abutments by the laboratory technician compared to that applied by the treating clinician. The purpose of this study was to measure the axial displacement of tapered cone-screw abutments into implants and their replicas as a function of the tightening torque level. Twenty tapered cone-screw abutments were selected. Two groups were created: 10 abutments were secured into 10 implants, and 10 abutments were secured into 10 corresponding implant replicas. Each abutment was tightened in increasing increments of 5 Ncm, from 0 Ncm to 45 Ncm, with a torque controller. The length of each sample was measured repeatedly with an Electronic Digital Micrometer. The mean axial displacement for the implant group and the replica group was calculated. The data were analyzed by the Mann-Whitney and Spearman tests. For both groups, there was always an axial displacement of the abutment upon each incremental application of torque. The mean axial displacement values varied between 7 and 12 microm for the implant group and between 6 and 21 microm for the replica group at each 5-Ncm increment. From 0 to 45 Ncm, the total mean axial displacement values were 89 microm for the implant group and 122 microm for the replica group. There was a continuous axial displacement of the abutments into implants and implant replicas when the applied torque was raised from 0 to 45 Ncm. Torque applied above the level recommended by the manufacturer increased the difference in displacement between the two groups.

Assessing Institutional Characteristics on Microcredit Default in Kenya: A Comparative Analysis of Microfinance Institutions and Financial Intermediaries

Science.gov (United States)

Muthoni, Muturi Phyllis

2016-01-01

A major concern on microcredit repayment remains a major obstacle to the Micro Financial Institutions (MFIs) and Financial Intermediaries (FIs) in Kenya. The health of MFI sector in Sub Sahara Africa (SSA) is a cause of concern due to the increased portfolio at risk (PAR). This region records the highest risk globally with its PAR 30 greater than…

Meat Processing Company Staff as Innovation Intermediaries: Developing a Framework from New Zealand's Red Meat Sector

Science.gov (United States)

Westbrooke, Victoria; Guenther, Meike; Bewsell, Denise; Greer, Glen

2018-01-01

Purpose: Meat processing companies have the potential to raise farm and sector productivity by directly working with farmers. This study assesses how commercial companies can undertake the roles of innovation intermediaries to increase productivity in New Zealand's sheep and beef sector. Design/methodology/approach: This study uses a case study…

Accuracy of Digital vs. Conventional Implant Impressions

Science.gov (United States)

Lee, Sang J.; Betensky, Rebecca A.; Gianneschi, Grace E.; Gallucci, German O.

2015-01-01

The accuracy of digital impressions greatly influences the clinical viability in implant restorations. The aim of this study is to compare the accuracy of gypsum models acquired from the conventional implant impression to digitally milled models created from direct digitalization by three-dimensional analysis. Thirty gypsum and 30 digitally milled models impressed directly from a reference model were prepared. The models were scanned by a laboratory scanner and 30 STL datasets from each group were imported to an inspection software. The datasets were aligned to the reference dataset by a repeated best fit algorithm and 10 specified contact locations of interest were measured in mean volumetric deviations. The areas were pooled by cusps, fossae, interproximal contacts, horizontal and vertical axes of implant position and angulation. The pooled areas were statistically analysed by comparing each group to the reference model to investigate the mean volumetric deviations accounting for accuracy and standard deviations for precision. Milled models from digital impressions had comparable accuracy to gypsum models from conventional impressions. However, differences in fossae and vertical displacement of the implant position from the gypsum and digitally milled models compared to the reference model, exhibited statistical significance (p<0.001, p=0.020 respectively). PMID:24720423

ABACC's laboratory intercomparison program

International Nuclear Information System (INIS)

Almeida, Gevaldo L. de; Esteban, Adolfo; Almeida, Silvio G. de; Araujo, Radier M. de; Rocha, Zildete

1996-01-01

A Laboratory Intercomparison Program involving Brazilian and Argentine laboratories, with the special participation of New Brunswick Laboratory - DOE and IAEA Seibersdorf Safeguards Laboratory, was implanted by ABACC having as main purpose to qualify a network to provide analytical services to this Agency on its role as administrator of the Common System of Accountability and Control of Nuclear Materials. For the first round robin of this Program, 15 laboratories were invited to perform elemental analysis on UO 2 samples, by using any desired method. Thirteen confirmed the participation and 10 reported the results. After an evaluation of the results by using a Two-Way Variance Analysis applied to a nested error model, it was found that 5 of them deviate less than 0.1% from the reference value established for the UO 2 uranium contents, being thus situated within the limits adopted for the target values, while the remaining ones reach a maximal deviation of 0.44%. The outcome of this evaluation, was sent to the laboratories, providing them with a feedback to improve their performance by applying corrective actions to the detected sources of errors or bias related to the methods techniques and procedures. (author)

Embryo-epithelium interactions during implantation at a glance.

Science.gov (United States)

Aplin, John D; Ruane, Peter T

2017-01-01

At implantation, with the acquisition of a receptive phenotype in the uterine epithelium, an initial tenuous attachment of embryonic trophectoderm initiates reorganisation of epithelial polarity to enable stable embryo attachment and the differentiation of invasive trophoblasts. In this Cell Science at a Glance article, we describe cellular and molecular events during the epithelial phase of implantation in rodent, drawing on morphological studies both in vivo and in vitro, and genetic models. Evidence is emerging for a repertoire of transcription factors downstream of the master steroidal regulators estrogen and progesterone that coordinate alterations in epithelial polarity, delivery of signals to the stroma and epithelial cell death or displacement. We discuss what is known of the cell interactions that occur during implantation, before considering specific adhesion molecules. We compare the rodent data with our much more limited knowledge of the human system, where direct mechanistic evidence is hard to obtain. In the accompanying poster, we represent the embryo-epithelium interactions in humans and laboratory rodents, highlighting similarities and differences, as well as depict some of the key cell biological events that enable interstitial implantation to occur. © 2017. Published by The Company of Biologists Ltd.

Intermediation in Foreign Trade: When do Exporters Rely on Intermediaries?

DEFF Research Database (Denmark)

Schröder, Philipp J.H.; Trabold, H.; Trübswetter, P.

2005-01-01

The paper explores the question of why trade intermediaries (TIs) are frequently used as agents for exports to some countries but not to others. First, we adapt a standard intra-industry trade model with variable export costs (e.g. transport) and fixed export costs (e.g. market access) to include...... a TI that is able to pool market access cost. This framework suggests explanatory factors for the TI share in a country's exports, which are largely in line with the literature. Second, we test these explanatory factors with a new data set based on French customs information. The paper finds that: (i......) higher market access costs increase the TI share, (ii) smaller export markets feature a larger TI share, (iii) network effects are important determinants of trade intermediation....

Short dental implants: an emerging concept in implant treatment.

Science.gov (United States)

Al-Hashedi, Ashwaq Ali; Taiyeb Ali, Tara Bai; Yunus, Norsiah

2014-06-01

Short implants have been advocated as a treatment option in many clinical situations where the use of conventional implants is limited. This review outlines the effectiveness and clinical outcomes of using short implants as a valid treatment option in the rehabilitation of edentulous atrophic alveolar ridges. Initially, an electronic search was performed on the following databases: Medline, PubMed, Embase, Cochrane Database of Systematic Reviews, and DARE using key words from January 1990 until May 2012. An additional hand search was included for the relevant articles in the following journals: International Journal of Oral and Maxillofacial Implants, Clinical Oral Implants Research, Journal of Clinical Periodontology, International Journal of Periodontics, Journal of Periodontology, and Clinical Implant Dentistry and Related Research. Any relevant papers from the journals' references were hand searched. Articles were included if they provided detailed data on implant length, reported survival rates, mentioned measures for implant failure, were in the English language, involved human subjects, and researched implants inserted in healed atrophic ridges with a follow-up period of at least 1 year after implant-prosthesis loading. Short implants demonstrated a high rate of success in the replacement of missing teeth in especially atrophic alveolar ridges. The advanced technology and improvement of the implant surfaces have encouraged the success of short implants to a comparable level to that of standard implants. However, further randomized controlled clinical trials and prospective studies with longer follow-up periods are needed.

A new nuclear materials laboratory at Queen's University

International Nuclear Information System (INIS)

Holt, R.A.; Daymond, M.R.

2015-01-01

The Reactor Materials Testing Laboratory (RMTL) at Queen's University and the results of commissioning tests are described. RMTL uses energetic protons (up to 8MeV) to simulate fast neutron damage in materials for reactor components. The laboratory is also capable of He implantation (up to 12 MeV) to simulate the effects of transmutation He in reactor components. The $17.5M laboratory comprises a new building, a 4MV tandem accelerator, two electron microscopes, mechanical testing and specimen preparation equipment, and a radiation detection laboratory. RMTL focusses on studying dynamic effects of irradiation (irradiation creep, irradiation growth, irradiation induced swelling, fatigue under irradiation) in-situ. (author)

The status of undergraduate implant education in dental schools outside the United States.

Science.gov (United States)

Seckinger, R J; Weintraub, A M; Berthold, P; Weintraub, G S

1995-01-01

Over the past 20 years the incorporation of implant dentistry into academia has been documented in some detail for North American dental schools but has not been pursued on an international level. In June of 1993, we surveyed 51 dental schools outside of the United States affiliated with the University of Pennsylvania School of Dental Medicine's Office of International Relations concerning their teaching involvement with implant dentistry. Results from the 44 (86 percent) responding schools suggest that implant dentistry is being incorporated into predoctoral curriculums. Industrialized countries were more inclined to provide implant education. Insufficient time and the thought that the predoctoral level was not the place for implant dentistry were cited as some of the reasons for not incorporating implant dentistry into the curriculum. Oral surgery, prosthodontics, and periodontics departments developed and administered the implant curriculum. Formats varied among schools with respect to allotted time, curricular placement, laboratory experience, and clinical participation. Didactic material most frequently presented included a historical overview, diagnosis and treatment planning, classification of dental implants, and surgical and prosthetic concepts. Clinical involvement varied from actual implant placement to observation of prosthodontic procedures. Results were categorized based on the TOEFL (Test of English as a Foreign Language) classification of countries in six regions.

Hip implants - Paper VI - Ion concentrations

Energy Technology Data Exchange (ETDEWEB)

Sargeant, A. [Department of Biological Sciences, Ohio Northern University, Ada, OH 45810 (United States); Goswami, T. [Department of Mechanical Engineering, Ohio Northern University, Ada, OH 45810 (United States)]. E-mail: t-goswami@onu.edu

2007-07-01

Total hip-joint arthroplasty is performed in increasing numbers where it translates to about 0.16-0.2% of population per year in industrial countries. In most cases, an implant is a metallic component articulating with a metal, ceramic or poly-ethylene liner as seen in the case of hip, knee and spine. The metal implants release ions in vivo. Therefore, there is a need to study metallic implants and ions released as a result. Toxic concentrations of ions can lead to many adverse physiological effects, including cytotoxicity, genotoxicity, carcinogenicity, and metal sensitivity. There is a need to map ion concentrations establishing boundaries between normal and toxic levels; which however, does not exist. Reference levels of ion concentrations in body fluids and tissues determined by many studies are compiled, reviewed, and presented in this paper. The concentrations of ions released from different alloys, including cobalt, chromium, nickel, molybdenum titanium, aluminum, and vanadium, are presented in this paper. This paper reviews the literature pertaining to clinical data on metal ion concentrations in patients with metal joint prostheses, and laboratory data on the physiological effects of the metals.

Ion beam stabilization in ion implantation equipment

International Nuclear Information System (INIS)

Pina, L.

1973-01-01

The results are presented of experimental efforts aimed at ion beam current stabilization in an equipment for ion implantation in solids. The related problems of power supplies are discussed. Measured characteristics of laboratory equipment served the determination of the parameters to be required of the supplies as well as the design and the construction of the supplies. The respective wiring diagram is presented. (J.K.)

Number of implants for mandibular implant overdentures: a systematic review

Science.gov (United States)

Lee, Jeong-Yol; Kim, Ha-Young; Bryant, S. Ross

2012-01-01

PURPOSE The aim of this systematic review is to address treatment outcomes of Mandibular implant overdentures relative to implant survival rate, maintenance and complications, and patient satisfaction. MATERIALS AND METHODS A systematic literature search was conducted by a PubMed search strategy and hand-searching of relevant journals from included studies. Randomized Clinical Trials (RCT) and comparative clinical trial studies on mandibular implant overdentures until August, 2010 were selected. Eleven studies from 1098 studies were finally selected and data were analyzed relative to number of implants. RESULTS Six studies presented the data of the implant survival rate which ranged from 95% to 100% for 2 and 4 implant group and from 81.8% to 96.1% for 1 and 2 implant group. One study, which statistically compared implant survival rate showed no significant differences relative to the number of implants. The most common type of prosthetic maintenance and complications were replacement or reattaching of loose clips for 2 and 4 implant group, and denture repair due to the fracture around an implant for 1 and 2 implant groups. Most studies showed no significant differences in the rate of prosthetic maintenance and complication, and patient satisfaction regardless the number of implants. CONCLUSION The implant survival rate of mandibular overdentures is high regardless of the number of implants. Denture maintenance is likely not inflenced substantially by the number of implants and patient satisfaction is typically high again regardless os the number of implants. PMID:23236572

Volatile organic compounds and good laboratory practices in the in vitro fertilization laboratory: the important parameters for successful outcome in extended culture.

Science.gov (United States)

Agarwal, Nupur; Chattopadhyay, Ratna; Ghosh, Sanghamitra; Bhoumik, Arpita; Goswami, S K; Chakravarty, Baidyanath

2017-08-01

This study aims to describe the role of implementing good laboratory practices to improve in vitro fertilization (IVF) outcomes which are of great interest for practitioners dealing with infertility. Certain modifications were introduced in May 2015 in our IVF laboratory like high-efficiency particulate air CODA system, steel furniture instead of wooden, use of new disinfectants like oosafe, and restriction of personnel entry along with avoidance of cosmetics like perfume to improve pregnancy rates. Volatile organic compound (VOC) meter reading was monitored at two time points and five different places in the laboratory to compare the embryonic development parameters before (group A: July 2014-April 2015) and after (group B: July 2015-April 2016) remodeling. The IVF outcomes from 1036 cycles were associated in this study. Reduction in VOC meter readings, enhanced air quality, improvement in blastocyst formation rate, implantation, and clinical pregnancy rate were observed in the laboratory after implementation of new facilities. Results illustrated that the attention must be focused on potential hazards which expose laboratories to elevated VOC levels. Blastocyst formation rate increased around 18%. Implantation rate, clinical pregnancy rate, and live birth rate increased by around 11, 10, and 8%, respectively. In conclusion, with proper engineering and material selection, we have been able to reduce chemical contamination and adverse effects on culture with optimized IVF results. None.

Demineralized bone matrix and human cancellous bone enhance fixation of titanium implants

DEFF Research Database (Denmark)

Babiker, Hassan; Ding, Ming; Overgaard, Søren

Best Poster 5Demineralized bone matrix and human cancellous bone enhance fixation of titanium implants AuthorsBabiker , H.; Ding M.; Overgaard S.InstitutionOrthopaedic Research Laboratory, Department of Orthopaedic Surgery, Odense University Hospital, Clinical Institute, University of Southern...... from human tissue were included (IsoTis OrthoBiologics, Inc. USA). Both materials are commercially available. Titanium alloy implants (Biomet Inc.) of 10 mm in length and 10 mm in diameter were inserted bilaterally into the femoral condyles of 8 skeletally mature sheep. Thus four implants...... with a concentric gap of 2 mm were implanted in each sheep. The gap was filled with: DBM; DBM/CB with ratio of 1/3; DBM/allograft with ratio of 1/3; or allograft (Gold standard), respectively. Standardised surgical procedure was used1. At sacrifice, 6 weeks after surgery, both distal femurs were harvested...

Primary prevention of peri-implantitis: managing peri-implant mucositis.

Science.gov (United States)

Jepsen, Søren; Berglundh, Tord; Genco, Robert; Aass, Anne Merete; Demirel, Korkud; Derks, Jan; Figuero, Elena; Giovannoli, Jean Louis; Goldstein, Moshe; Lambert, France; Ortiz-Vigon, Alberto; Polyzois, Ioannis; Salvi, Giovanni E; Schwarz, Frank; Serino, Giovanni; Tomasi, Cristiano; Zitzmann, Nicola U

2015-04-01

Over the past decades, the placement of dental implants has become a routine procedure in the oral rehabilitation of fully and partially edentulous patients. However, the number of patients/implants affected by peri-implant diseases is increasing. As there are--in contrast to periodontitis--at present no established and predictable concepts for the treatment of peri-implantitis, primary prevention is of key importance. The management of peri-implant mucositis is considered as a preventive measure for the onset of peri-implantitis. Therefore, the remit of this working group was to assess the prevalence of peri-implant diseases, as well as risks for peri-implant mucositis and to evaluate measures for the management of peri-implant mucositis. Discussions were informed by four systematic reviews on the current epidemiology of peri-implant diseases, on potential risks contributing to the development of peri-implant mucositis, and on the effect of patient and of professionally administered measures to manage peri-implant mucositis. This consensus report is based on the outcomes of these systematic reviews and on the expert opinion of the participants. Key findings included: (i) meta-analysis estimated a weighted mean prevalence for peri-implant mucositis of 43% (CI: 32-54%) and for peri-implantitis of 22% (CI: 14-30%); (ii) bleeding on probing is considered as key clinical measure to distinguish between peri-implant health and disease; (iii) lack of regular supportive therapy in patients with peri-implant mucositis was associated with increased risk for onset of peri-implantitis; (iv) whereas plaque accumulation has been established as aetiological factor, smoking was identified as modifiable patient-related and excess cement as local risk indicator for the development of peri-implant mucositis; (v) patient-administered mechanical plaque control (with manual or powered toothbrushes) has been shown to be an effective preventive measure; (vi) professional intervention

A decomposable silica-based antibacterial coating for percutaneous titanium implant

Directory of Open Access Journals (Sweden)

Wang J

2017-01-01

Full Text Available Jia Wang,1,* Guofeng Wu,2,* Xiangwei Liu,3,* Guanyang Sun,1 Dehua Li,3 Hongbo Wei3 1State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi’an, 2Department of Prosthodontics, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, 3State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases & Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, Department of Oral Implants, School of Stomatology, The Fourth Military Medical University, Xi’an, People’s Republic of China *These authors contributed equally to this work Abstract: Although percutaneous titanium implants have become one of the best choices as retainers in the facial defects, peri-implantitis still occurs at a significant rate. This unwanted complication occurs due to adhesion of bacteria and subsequent biofilm formation. To solve this problem, we have developed a novel antibiotic nanodelivery system based on self-decomposable silica nanoparticles. In this study, silica-gentamycin (SG nanoparticles were successfully fabricated using an innovative one-pot solution. The nanoparticles were incorporated within a gelatin matrix and cross-linked on microarc-oxidized titanium. To characterize the SG nanoparticles, their particle size, zeta potential, surface morphology, in vitro drug release, and decomposition process were sequentially evaluated. The antibacterial properties against the gram-positive Staphylococcus aureus, including bacterial viability, antibacterial rate, and bacteria morphology, were analyzed using SG-loaded titanium specimens. Any possible influence of released gentamycin on the viability of human fibroblasts, which are the main component of soft tissues, was investigated. SG nanoparticles from the

Scalloped Implant-Abutment Connection Compared to Conventional Flat Implant-Abutment Connection

DEFF Research Database (Denmark)

Starch-Jensen, Thomas; Christensen, Ann-Eva; Lorenzen, Henning

2017-01-01

OBJECTIVES: The objective was to test the hypothesis of no difference in implant treatment outcome after installation of implants with a scalloped implant-abutment connection compared to a flat implant-abutment connection. MATERIAL AND METHODS: A MEDLINE (PubMed), Embase and Cochrane library search...... of suprastructures has never been compared within the same study. High implant survival rate was reported in all the included studies. Significantly more peri-implant marginal bone loss, higher probing depth score, bleeding score and gingival score was observed around implants with a scalloped implant-abutment...... loss around implants with a scalloped implant-abutment connection. CONCLUSIONS: A scalloped implant-abutment connection seems to be associated with higher peri-implant marginal bone loss compared to a flat implant-abutment connection. Therefore, the hypothesis of the present systematic review must...

Plasma source ion implantation of metal ions: Synchronization of cathodic-arc plasma production and target bias pulses

International Nuclear Information System (INIS)

Wood, B.P.; Reass, W.A.; Henins, I.

1995-01-01

An erbium cathodic-arc has been installed on a Plasma Source Ion Implantation (PSII) experiment to allow the implantation of erbium metal and the growth of adherent erbia (erbium oxide) films on a variety of substrates. Operation of the PSII pulser and the cathodic-arc are synchronized to achieve pure implantation, rather than the hybrid implantation/deposition being investigated in other laboratories. The relative phase of the 20 μs PSII and cathodic-arc pulses can to adjusted to tailor the energy distribution of implanted ions and suppress the initial high-current drain on the pulse modulator. The authors present experimental data on this effect and make a comparison to results from particle-in-cell simulations

Tensions in firm-community collaboration and the role of intermediaries in exploiting synergies

DEFF Research Database (Denmark)

Dragsdahl Lauritzen, Ghita; Salomo, Søren

2013-01-01

and firms have become central to value creation. This is also reflected in an increasing interest in user-driven innovation. However, from the context in which firms and communities intersect, tensions arise due to undefined boundaries and a lack of clear roles. Although, intermediaries such as service...... and as dilemmas relating to power, identity, and competence that must be balanced in order to encourage and benefit from user contributions. Introducing Systems theory this paper shows that what is currently described as dilemmas that must be managed, are in fact paradoxes that are mutually enabling and must...

Independent and additive association of prenatal famine exposure and intermediary life conditions with adult mortality between age 18-63 years

NARCIS (Netherlands)

Ekamper, P.; van Poppel, F.W.A.; Stein, A.D.; Lumey, L.H.

2014-01-01

Objectives To quantify the relation between prenatal famine exposure and adult mortality, taking into account mediating effects of intermediary life conditions. Design Historical follow-up study. Setting The Dutch famine (Hunger Winter) of 1944–1945 which occurred towards the end of WWII in occupied

Bone integration capability of nanopolymorphic crystalline hydroxyapatite coated on titanium implants

Directory of Open Access Journals (Sweden)

Suzuki T

2012-02-01

Full Text Available Masahiro Yamada*, Takeshi Ueno*, Naoki Tsukimura, Takayuki Ikeda, Kaori Nakagawa, Norio Hori, Takeo Suzuki, Takahiro OgawaLaboratory of Bone and Implant Sciences, The Weintraub Center for Reconstructive Biotechnology, Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, UCLA School of Dentistry, Los Angeles, CA, USA *These authors contributed equally to this workAbstract: The mechanism by which hydroxyapatite (HA-coated titanium promotes bone–implant integration is largely unknown. Furthermore, refining the fabrication of nanostructured HA to the level applicable to the mass production process for titanium implants is challenging. This study reports successful creation of nanopolymorphic crystalline HA on microroughened titanium surfaces using a combination of flame spray and low-temperature calcination and tests its biological capability to enhance bone–implant integration. Sandblasted microroughened titanium implants and sandblasted + HA-coated titanium implants were subjected to biomechanical and histomorphometric analyses in a rat model. The HA was 55% crystallized and consisted of nanoscale needle-like architectures developed in various diameters, lengths, and orientations, which resulted in a 70% increase in surface area compared to noncoated microroughened surfaces. The HA was free from impurity contaminants, with a calcium/phosphorus ratio of 1.66 being equivalent to that of stoichiometric HA. As compared to microroughened implants, HA-coated implants increased the strength of bone–implant integration consistently at both early and late stages of healing. HA-coated implants showed an increased percentage of bone–implant contact and bone volume within 50 µm proximity of the implant surface, as well as a remarkably reduced percentage of soft tissue intervention between bone and the implant surface. In contrast, bone volume outside the 50 µm border was lower around HA-coated implants. Thus, this study

The relationship of silicone breast implants and cancer at other sites.

Science.gov (United States)

Brinton, Louise A

2007-12-01

Although most attention regarding the effects of silicone breast implants on cancer risk has focused on breast cancer, there have also been concerns regarding effects on other cancers. This includes malignancies that could occur as a result of foreign-body carcinogenesis (sarcomas) or immune alterations (hematopoietic malignancies), or cancers suggested as possibly elevated on the basis of previous epidemiologic studies (cancers of the cervix, vulva, lung, and brain). Searches of the English language literature on the topic of silicone breast implants and cancer risk were conducted and reviewed to determine relationships that might have etiologic relevance. Epidemiologic studies provide no support for an increased risk of either sarcoma or multiple myeloma among breast implant recipients, disputing clinical and laboratory findings suggesting such a link. Although a number of epidemiologic studies have demonstrated elevated risks of cervical, vulvar, and lung cancers among breast implant patients, it is likely that these excesses relate more to lifestyle characteristics (e.g., cigarette smoking, sexual behavior) than to the effects of the implants. Brain cancer excesses, suggested in one study, have not been confirmed in either an update of the mortality experience in this study or on the basis of other investigations. At present, there is no convincing evidence that breast implants alter the risk of nonbreast malignancies. Breast implant patients should continue to be monitored for longer term risks and to assess whether cancer risk is influenced by various patient and implant characteristics.

Comparison of two multiaxial fatigue models applied to dental implants

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JM. Ayllon

2015-07-01

Full Text Available This paper presents two multiaxial fatigue life prediction models applied to a commercial dental implant. One model is called Variable Initiation Length Model and takes into account both the crack initiation and propagation phases. The second model combines the Theory of Critical Distance with a critical plane damage model to characterise the initiation and initial propagation of micro/meso cracks in the material. This paper discusses which material properties are necessary for the implementation of these models and how to obtain them in the laboratory from simple test specimens. It also describes the FE models developed for the stress/strain and stress intensity factor characterisation in the implant. The results of applying both life prediction models are compared with experimental results arising from the application of ISO-14801 standard to a commercial dental implant.

Gingival recontouring by provisional implant restoration for optimal emergence profile: report of two cases.

Science.gov (United States)

Son, Mee-Kyoung; Jang, Hyun-Seon

2011-12-01

The emergence profile concept of an implant restoration is one of the most important factors for the esthetics and health of peri-implant soft tissue. This paper reports on two cases of gingival recontouring by the fabrication of a provisional implant restoration to produce an optimal emergence profile of a definitive implant restoration. After the second surgery, a preliminary impression was taken to make a soft tissue working cast. A provisional crown was fabricated on the model. The soft tissue around the implant fixture on the model was trimmed with a laboratory scalpel to produce the scalloped gingival form. Light curing composite resin was added to fill the space between the provisional crown base and trimmed gingiva. After 4 to 6 weeks, the final impression was taken to make a definitive implant restoration, where the soft tissue and tooth form were in harmony with the adjacent tooth. At the first insertion of the provisional restoration, gum bleaching revealed gingival pressure. Four to six weeks after placing the provisional restoration, the gum reformed with harmony between the peri-implant gingiva and adjacent dentition. Gingival recontouring with a provisional implant restoration is a non-surgical and non-procedure-sensitive method. The implant restoration with the optimal emergence profile is expected to provide superior esthetic and functional results.

Comparison of migration behavior between single and dual lag screw implants for intertrochanteric fracture fixation

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Katonis Pavlos G

2009-05-01

Full Text Available Abstract Background Lag screw cut-out failure following fixation of unstable intertrochanteric fractures in osteoporotic bone remains an unsolved challenge. This study tested if resistance to cut-out failure can be improved by using a dual lag screw implant in place of a single lag screw implant. Migration behavior and cut-out resistance of a single and a dual lag screw implant were comparatively evaluated in surrogate specimens using an established laboratory model of hip screw cut-out failure. Methods Five dual lag screw implants (Endovis, Citieffe and five single lag screw implants (DHS, Synthes were tested in the Hip Implant Performance Simulator (HIPS of the Legacy Biomechanics Laboratory. This model simulated osteoporotic bone, an unstable fracture, and biaxial rocking motion representative of hip loading during normal gait. All constructs were loaded up to 20,000 cycles of 1.45 kN peak magnitude under biaxial rocking motion. The migration kinematics was continuously monitored with 6-degrees of freedom motion tracking system and the number of cycles to implant cut-out was recorded. Results The dual lag screw implant exhibited significantly less migration and sustained more loading cycles in comparison to the DHS single lag screw. All DHS constructs failed before 20,000 cycles, on average at 6,638 ± 2,837 cycles either by cut-out or permanent screw bending. At failure, DHS constructs exhibited 10.8 ± 2.3° varus collapse and 15.5 ± 9.5° rotation around the lag screw axis. Four out of five dual screws constructs sustained 20,000 loading cycles. One dual screw specimens sustained cut-out by medial migration of the distal screw after 10,054 cycles. At test end, varus collapse and neck rotation in dual screws implants advanced to 3.7 ± 1.7° and 1.6 ± 1.0°, respectively. Conclusion The single and double lag screw implants demonstrated a significantly different migration resistance in surrogate specimens under gait loading simulation with

Why are mini-implants lost: the value of the implantation technique!

Science.gov (United States)

Romano, Fabio Lourenço; Consolaro, Alberto

2015-01-01

The use of mini-implants have made a major contribution to orthodontic treatment. Demand has aroused scientific curiosity about implant placement procedures and techniques. However, the reasons for instability have not yet been made totally clear. The aim of this article is to establish a relationship between implant placement technique and mini-implant success rates by means of examining the following hypotheses: 1) Sites of poor alveolar bone and little space between roots lead to inadequate implant placement; 2) Different sites require mini-implants of different sizes! Implant size should respect alveolar bone diameter; 3) Properly determining mini-implant placement site provides ease for implant placement and contributes to stability; 4) The more precise the lancing procedures, the better the implant placement technique; 5) Self-drilling does not mean higher pressures; 6) Knowing where implant placement should end decreases the risk of complications and mini-implant loss.

Why are mini-implants lost: The value of the implantation technique!

Directory of Open Access Journals (Sweden)

Fabio Lourenço Romano

2015-02-01

Full Text Available The use of mini-implants have made a major contribution to orthodontic treatment. Demand has aroused scientific curiosity about implant placement procedures and techniques. However, the reasons for instability have not yet been made totally clear. The aim of this article is to establish a relationship between implant placement technique and mini-implant success rates by means of examining the following hypotheses: 1 Sites of poor alveolar bone and little space between roots lead to inadequate implant placement; 2 Different sites require mini-implants of different sizes! Implant size should respect alveolar bone diameter; 3 Properly determining mini-implant placement site provides ease for implant placement and contributes to stability; 4 The more precise the lancing procedures, the better the implant placement technique; 5 Self-drilling does not mean higher pressures; 6 Knowing where implant placement should end decreases the risk of complications and mini-implant loss.

Effect of macronutrient ratio of the pre-starter diet on broiler performance and intermediary metabolism

OpenAIRE

SWENNEN, Quirine; Everaert, N.; Debonne, M.; Verbaeys, I.; Careghi, C.; Tona, K.; Janssens, G. P. J.; Decuypere, E.; Bruggeman, V.; Buyse, J.

2010-01-01

P>The aim of this study was to investigate the influence of isoenergetic substitution between the three energy delivering macronutrients in pre-starter diets on performance and intermediary nutrient metabolism in broiler chickens. From hatch until 5 days of age, 600 chicks, collected during peak of hatch, were fed one of the three experimental pre-starter diets with isoenergetic (13 MJ metabolisable energy/kg) substitutions between fat (43 vs. 108 g/kg), protein (126 vs. 240 g/kg) and carbohy...

The role of intermediaries in delivering an occupational health and safety programme designed for small business - a case study of an insurance incentive programme in the agriculture sector

DEFF Research Database (Denmark)

Olsen, Kirsten Bendix; Hasle, Peter

2015-01-01

to the transformation and dissemination of a national OHS programme for small business that built on an Insurance incentive scheme – the New Zealand Workplace Safety Discount scheme. It is a case study of this scheme implementation in the agriculture sector. Data was collected from scheme documentation and semi......-structured interviews with the scheme owner, representatives from intermediary groups and the targeted small businesses. The interviews were tape recorded, transcribed and thematically analysed in relation to the scheme’s programme theory. The intermediaries introduced new programme mechanisms and recruitment...

Qualification of testing laboratories of Comision Nacional de Energia Atomica - CNEA

International Nuclear Information System (INIS)

Casa, Adriana; Palacios, Tulio; Peretti, Matilde; Pucci, Gladys; Resnizki, Sara

1996-01-01

Testing and calibration laboratories of the Argentine Atomic Energy Commission which made services for the nuclear and conventional industries must prove the reliability of their results. It is achieved implanting at the laboratories, a management quality system, to proof the capacity and technical aptitude, with the establish minimal requirements. When the requirement are fulfilled, the laboratory would be in conditions for a national level accreditation within the National System of Standards, Quality and Certification, recently created for our national government. The Laboratories Calibration Board of CNEA had made some assessments of a group of laboratories in order to determine their quality level. (author)

Primary prevention of peri-implantitis: Managing peri-implant mucositis

OpenAIRE

Jepsen, Søren; Berglundh, Tord; Genco, Robert; Aass, Anne Merete; Demirel, Korkud; Derks, Jan; Figuero, Elena; Giovannoli, Jean Louis; Goldstein, Moshe; LAMBERT, France; Ortiz-Vigon, Alberto; Polyzois, Ioannis; Salvi, Giovanni; Schwarz, Frank; Serino, Giovanni

2015-01-01

Abstract AIMS: Over the past decades, the placement of dental implants has become a routine procedure in the oral rehabilitation of fully and partially edentulous patients. However, the number of patients/implants affected by peri-implant diseases is increasing. As there are--in contrast to periodontitis--at present no established and predictable concepts for the treatment of peri-implantitis, primary prevention is of key importance. The management of peri-implant mucositis is considere...

Mechanical design, analysis, and laboratory testing of a dental implant with axial flexibility similar to natural tooth with periodontal ligament.

Science.gov (United States)

Pektaş, Ömer; Tönük, Ergin

2014-11-01

At the interface between the jawbone and the roots of natural teeth, a thin, elastic, shock-absorbing tissue, called the periodontal ligament, forms a cushion which provides certain flexibility under mechanical loading. The dental restorations supported by implants, however, involve comparatively rigid connections to the jawbone. This causes overloading of the implant while bearing functional loading together with neighboring natural teeth, which leads to high stresses within the implant system and in the jawbone. A dental implant, with resilient components in the upper structure (abutment) in order to mimic the mechanical behavior of the periodontal ligament in the axial direction, was designed, analyzed in silico, and produced for mechanical testing. The aims of the design were avoiding high levels of stress, loosening of the abutment connection screw, and soft tissue irritations. The finite element analysis of the designed implant revealed that the elastic abutment yielded a similar axial mobility with the natural tooth while keeping stress in the implant at safe levels. The in vitro mechanical testing of the prototype resulted in similar axial mobility predicted by the analysis and as that of a typical natural tooth. The abutment screw did not loosen under repeated loading and there was no static or fatigue failure. © IMechE 2014.

Coherent Synchrotron-Based Micro-Imaging Employed for Studies of Micro-Gap Formation in Dental Implants

International Nuclear Information System (INIS)

Rack, T.; Stiller, M.; Nelson, K.; Zabler, S.; Rack, A.; Riesemeier, H.; Cecilia, A.

2011-01-01

Biocompatible materials such as titanium are regularly applied in oral surgery. Titanium-based implants for the replacement of missing teeth demand a high mechanical precision in order to minimize micro-bacterial leakage, especially when two-piece concepts are used. Synchrotron-based hard x-ray radiography, unlike conventional laboratory radiography, allows high spatial resolution in combination with high contrast even when micro-sized features in such highly attenuating objects are visualized. Therefore, micro-gap formation at interfaces in two-piece dental implants with the sample under different mechanical loads can be studied. We show the existence of micro-gaps in implants with conical connections and study the mechanical behavior of the mating zone of conical implants during loading. The micro-gap is a potential source of implant failure, i.e., bacterial leakage, which can be a stimulus for an inflammatory process.

Osteogenesis and Morphology of the Peri-Implant Bone Facing Dental Implants

Directory of Open Access Journals (Sweden)

Marco Franchi

2004-01-01

Full Text Available This study investigated the influence of different implant surfaces on peri-implant osteogenesis and implant face morphology of peri-implant tissues during the early (2 weeks and complete healing period (3 months. Thirty endosseous titanium implants (conic screws with differently treated surfaces (smooth titanium = SS, titanium plasma sprayed = TPS, sand-blasted zirconium oxide = Zr-SLA were implanted in femur and tibiae diaphyses of two mongrel sheep. Histological sections of the implants and surrounding tissues obtained by sawing and grinding techniques were observed under light microscopy (LM. The peri-implant tissues of other samples were mechanically detached from the corresponding implants to be processed for SEM observation. Two weeks after implantation, we observed osteogenesis (new bone trabeculae around all implant surfaces only where a gap was present at the host bone-metal interface. No evident bone deposition was detectable where threads of the screws were in direct contact with the compact host bone. Distance osteogenesis predominated in SS implants, while around rough surfaces (TPS and Zr-SLA, both distance and contact osteogenesis were present. At SEM analysis 2 weeks after implantation, the implant face of SS peri-implant tissue showed few, thin, newly formed, bone trabeculae immersed in large, loose, marrow tissue with blood vessels. Around the TPS screws, the implant face of the peri-implant tissue was rather irregular because of the rougher metal surface. Zr-SLA screws showed more numerous, newly formed bone trabeculae crossing marrow spaces and also needle-like crystals in bone nodules indicating an active mineralising process. After 3 months, all the screws appeared osseointegrated, being almost completely covered by a compact, mature, newly formed bone. However, some marrow spaces rich in blood vessels and undifferentiated cells were in contact with the metal surface. By SEM analysis, the implant face of the peri-implant

Accuracy of 3 different impression techniques for internal connection angulated implants.

Science.gov (United States)

Tsagkalidis, George; Tortopidis, Dimitrios; Mpikos, Pavlos; Kaisarlis, George; Koidis, Petros

2015-10-01

Making implant impressions with different angulations requires a more precise and time-consuming impression technique. The purpose of this in vitro study was to compare the accuracy of nonsplinted, splinted, and snap-fit impression techniques of internal connection implants with different angulations. An experimental device was used to allow a clinical simulation of impression making by means of open and closed tray techniques. Three different impression techniques (nonsplinted, acrylic-resin splinted, and indirect snap-fit) for 6 internal-connected implants at different angulations (0, 15, 25 degrees) were examined using polyether. Impression accuracy was evaluated by measuring the differences in 3-dimensional (3D) position deviations between the implant body/impression coping before the impression procedure and the coping/laboratory analog positioned within the impression, using a coordinate measuring machine. Data were analyzed by 2-way ANOVA. Means were compared with the least significant difference criterion at Pimpression technique exhibited a higher accuracy than the other techniques studied when increased implant angulations at 25 degrees were involved. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Survival of dental implants placed in sites of previously failed implants.

Science.gov (United States)

Chrcanovic, Bruno R; Kisch, Jenö; Albrektsson, Tomas; Wennerberg, Ann

2017-11-01

To assess the survival of dental implants placed in sites of previously failed implants and to explore the possible factors that might affect the outcome of this reimplantation procedure. Patients that had failed dental implants, which were replaced with the same implant type at the same site, were included. Descriptive statistics were used to describe the patients and implants; survival analysis was also performed. The effect of systemic, environmental, and local factors on the survival of the reoperated implants was evaluated. 175 of 10,096 implants in 98 patients were replaced by another implant at the same location (159, 14, and 2 implants at second, third, and fourth surgeries, respectively). Newly replaced implants were generally of similar diameter but of shorter length compared to the previously placed fixtures. A statistically significant greater percentage of lost implants were placed in sites with low bone quantity. There was a statistically significant difference (P = 0.032) in the survival rates between implants that were inserted for the first time (94%) and implants that replaced the ones lost (73%). There was a statistically higher failure rate of the reoperated implants for patients taking antidepressants and antithrombotic agents. Dental implants replacing failed implants had lower survival rates than the rates reported for the previous attempts of implant placement. It is suggested that a site-specific negative effect may possibly be associated with this phenomenon, as well as the intake of antidepressants and antithrombotic agents. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Contribution of immunology to implantation failure of euploid embryos.

Science.gov (United States)

Franasiak, Jason M; Scott, Richard T

2017-06-01

Outcomes in assisted reproduction have seen marked improvement. With increased ability in the embryology laboratory to use extended embryo culture which in turn enables other selective techniques, such as trophectoderm biopsy and comprehensive chromosome screening, the chance of success per embryo transfer is increased. However, even the selection of a euploid blastocyst, which selects out many embryonic factors, does not yield successful implantation and ultimately delivery in all cases. Among the factors that affect implantation failure of apparently reproductively competent embryos, the immune system has been perhaps both the most plausible and the most debated. There are data on T-helper cells, in particular the T H 1-T H 2 balance, peripheral and uterine natural killer cells, and autoantibodies, all of which have been shown to have variable effects on implantation. Many investigators have developed and used a wide range of immune tests and treatments aimed at manipulating the milieu to favor implantation. Although it is certain that the immune system plays a role in implantation, our understanding of the physiology, let alone the pathophysiology, remains incomplete. It is imperative that we gain more clear evidence of causes and test and implement treatment paradigms. In the meantime, immune testing or empirical treatment with the use of immune modulators must be approached with caution. Copyright © 2017 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Sub-meninges implantation reduces immune response to neural implants.

Science.gov (United States)

Markwardt, Neil T; Stokol, Jodi; Rennaker, Robert L

2013-04-15

Glial scar formation around neural interfaces inhibits their ability to acquire usable signals from the surrounding neurons. To improve neural recording performance, the inflammatory response and glial scarring must be minimized. Previous work has indicated that meningeally derived cells participate in the immune response, and it is possible that the meninges may grow down around the shank of a neural implant, contributing to the formation of the glial scar. This study examines whether the glial scar can be reduced by placing a neural probe completely below the meninges. Rats were implanted with sets of loose microwire implants placed either completely below the meninges or implanted conventionally with the upper end penetrating the meninges, but not attached to the skull. Histological analysis was performed 4 weeks following surgical implantation to evaluate the glial scar. Our results found that sub-meninges implants showed an average reduction in reactive astrocyte activity of 63% compared to trans-meninges implants. Microglial activity was also reduced for sub-meninges implants. These results suggest that techniques that isolate implants from the meninges offer the potential to reduce the encapsulation response which should improve chronic recording quality and stability. Published by Elsevier B.V.

Fabricating CAD/CAM Implant-Retained Mandibular Bar Overdentures: A Clinical and Technical Overview

Directory of Open Access Journals (Sweden)

Chui Ling Goo

2017-01-01

Full Text Available This report describes the clinical and technical aspects in the oral rehabilitation of an edentulous patient with knife-edge ridge at the mandibular anterior edentulous region, using implant-retained overdentures. The application of computer-aided design and computer-aided manufacturing (CAD/CAM in the fabrication of the overdenture framework simplifies the laboratory process of the implant prostheses. The Nobel Procera CAD/CAM System was utilised to produce a lightweight titanium overdenture bar with locator attachments. It is proposed that the digital workflow of CAD/CAM milled implant overdenture bar allows us to avoid numerous technical steps and possibility of casting errors involved in the conventional casting of such bars.

Scalloped Implant-Abutment Connection Compared to Conventional Flat Implant-Abutment Connection

DEFF Research Database (Denmark)

Starch-Jensen, Thomas; Christensen, Ann-Eva; Lorenzen, Henning

2017-01-01

OBJECTIVES: The objective was to test the hypothesis of no difference in implant treatment outcome after installation of implants with a scalloped implant-abutment connection compared to a flat implant-abutment connection. MATERIAL AND METHODS: A MEDLINE (PubMed), Embase and Cochrane library search......-abutment connection. There were no significant differences between the two treatment modalities regarding professional or patient-reported outcome measures. Meta-analysis disclosed a mean difference of peri-implant marginal bone loss of 1.56 mm (confidence interval: 0.87 to 2.25), indicating significant more bone...... loss around implants with a scalloped implant-abutment connection. CONCLUSIONS: A scalloped implant-abutment connection seems to be associated with higher peri-implant marginal bone loss compared to a flat implant-abutment connection. Therefore, the hypothesis of the present systematic review must...

In vitro synchrotron-based radiography of micro-gap formation at the implant–abutment interface of two-piece dental implants

International Nuclear Information System (INIS)

Rack, A.; Rack, T.; Stiller, M.; Riesemeier, H.; Zabler, S.; Nelson, K.

2010-01-01

Micro-radiography using hard X-ray synchrotron radiation is the first potential tool to allow an evaluation of the mechanical behavior of the dental implant–abutment complex during force application, thus enabling the enhancement of the design of dental implants which has been based on theoretical analysis to date. Micro-gap formation at the implant–abutment interface of two-piece dental implants was investigated in vitro using high-resolution radiography in combination with hard X-ray synchrotron radiation. Images were taken with the specimen under different mechanical loads of up to 100 N. The aim of this investigation was to prove the existence of micro-gaps for implants with conical connections as well as to study the mechanical behavior of the mating zone of conical implants during loading. Synchrotron-based radiography in comparison with classical laboratory radiography yields high spatial resolution in combination with high contrast even when exploiting micro-sized features in highly attenuating objects. The first illustration of a micro-gap which was previously indistinguishable by laboratory methods underlines that the complex micro-mechanical behavior of implants requires further in vitro investigations where synchrotron-based micro-imaging is one of the prerequisites

In vitro synchrotron-based radiography of micro-gap formation at the implant–abutment interface of two-piece dental implants

Energy Technology Data Exchange (ETDEWEB)

Rack, A., E-mail: arack@snafu.de [European Synchrotron Radiation Facility, Grenoble (France); Rack, T. [Charité, Department of Oral and Maxillofacial Surgery, Clinical Navigation and Robotics, Berlin (Germany); Stiller, M. [Charité, Department of Maxillofacial and Facial-Plastic Surgery, Division of Oral Medicine, Radiology and Surgery, Berlin (Germany); Riesemeier, H. [Bundesanstalt für Materialforschung und -prüfung, Division Structure Analysis, Polymer Analysis, Berlin (Germany); Zabler, S. [Technical University of Berlin, Institute for Materials Engineering (Germany); Nelson, K. [Charité, Department of Oral and Maxillofacial Surgery, Clinical Navigation and Robotics, Berlin (Germany)

2010-03-01

Micro-radiography using hard X-ray synchrotron radiation is the first potential tool to allow an evaluation of the mechanical behavior of the dental implant–abutment complex during force application, thus enabling the enhancement of the design of dental implants which has been based on theoretical analysis to date. Micro-gap formation at the implant–abutment interface of two-piece dental implants was investigated in vitro using high-resolution radiography in combination with hard X-ray synchrotron radiation. Images were taken with the specimen under different mechanical loads of up to 100 N. The aim of this investigation was to prove the existence of micro-gaps for implants with conical connections as well as to study the mechanical behavior of the mating zone of conical implants during loading. Synchrotron-based radiography in comparison with classical laboratory radiography yields high spatial resolution in combination with high contrast even when exploiting micro-sized features in highly attenuating objects. The first illustration of a micro-gap which was previously indistinguishable by laboratory methods underlines that the complex micro-mechanical behavior of implants requires further in vitro investigations where synchrotron-based micro-imaging is one of the prerequisites.

Imaging of common breast implants and implant-related complications: A pictorial essay.

Science.gov (United States)

Shah, Amisha T; Jankharia, Bijal B

2016-01-01

The number of women undergoing breast implant procedures is increasing exponentially. It is, therefore, imperative for a radiologist to be familiar with the normal and abnormal imaging appearances of common breast implants. Diagnostic imaging studies such as mammography, ultrasonography, and magnetic resonance imaging are used to evaluate implant integrity, detect abnormalities of the implant and its surrounding capsule, and detect breast conditions unrelated to implants. Magnetic resonance imaging of silicone breast implants, with its high sensitivity and specificity for detecting implant rupture, is the most reliable modality to asses implant integrity. Whichever imaging modality is used, the overall aim of imaging breast implants is to provide the pertinent information about implant integrity, detect implant failures, and to detect breast conditions unrelated to the implants, such as cancer.

Immediate Direct-To-Implant Breast Reconstruction Using Anatomical Implants

Directory of Open Access Journals (Sweden)

Sung-Eun Kim

2014-09-01

Full Text Available BackgroundIn 2012, a new anatomic breast implant of form-stable silicone gel was introduced onto the Korean market. The intended use of this implant is in the area of aesthetic breast surgery, and many reports are promising. Thus far, however, there have been no reports on the use of this implant for breast reconstruction in Korea. We used this breast implant in breast reconstruction surgery and report our early experience.MethodsFrom November 2012 to April 2013, the Natrelle Style 410 form-stable anatomically shaped cohesive silicone gel-filled breast implant was used in 31 breasts of 30 patients for implant breast reconstruction with an acellular dermal matrix. Patients were treated with skin-sparing mastectomies followed by immediate breast reconstruction.ResultsThe mean breast resection volume was 240 mL (range, 83-540 mL. The mean size of the breast implants was 217 mL (range, 125-395 mL. Breast shape outcomes were considered acceptable. Infection and skin thinning occurred in one patient each, and hematoma and seroma did not occur. Three cases of wound dehiscence occurred, one requiring surgical intervention, while the others healed with conservative treatment in one month. Rippling did not occur. So far, complications such as capsular contracture and malrotation of breast implant have not yet arisen.ConclusionsBy using anatomic breast implants in breast reconstruction, we achieved satisfactory results with aesthetics better than those obtained with round breast implants. Therefore, we concluded that the anatomical implant is suitable for breast reconstruction.

Eyes on the prize: reflections on the impact of the evolving digital ecology on the librarian as expert intermediary and knowledge coach, 1969-2009.

Science.gov (United States)

Homan, J Michael

2010-01-01

The 2009 Janet Doe Lecture reflects on the continuing value and increasing return on investment of librarian-mediated services in the constantly evolving digital ecology and complex knowledge environment of the health sciences. The interrelationship of knowledge, decision making based on knowledge, technology used to access and retrieve knowledge, and the important linkage roles of expert librarian intermediaries is examined. Professional experiences from 1969 to 2009, occurring during a time of unprecedented changes in the digital ecology of librarianship, are the base on which the evolving role and value of librarians as knowledge coaches and expert intermediaries are examined. Librarian-mediated services linking knowledge and critical decision making in health care have become more valuable than ever as technology continues to reshape an increasingly complex knowledge environment.

Increasing levels of dietary crystalline methionine affect plasma methionine profiles, ammonia excretion, and the expression of genes related to the hepatic intermediary metabolism in rainbow trout (Oncorhynchus mykiss)

DEFF Research Database (Denmark)

Rolland, Marine; Skov, Peter Vilhelm; Larsen, Bodil Katrine

2016-01-01

Strictly carnivorous fish with high requirements for dietary protein, such as rainbow trout (Oncorhynchus mykiss) are interesting models for studying the role of amino acids as key regulators of intermediary metabolism. Methionine is an essential amino acid for rainbow trout, and works as a signa......Strictly carnivorous fish with high requirements for dietary protein, such as rainbow trout (Oncorhynchus mykiss) are interesting models for studying the role of amino acids as key regulators of intermediary metabolism. Methionine is an essential amino acid for rainbow trout, and works...... as a signalling factor in different metabolic pathways. The study investigated the effect of increasing dietary methionine intake on the intermediary metabolism in the liver of juvenile rainbow trout. For this purpose, five diets were formulated with increasing methionine levels from 0.60 to 1.29% dry matter....... The diets were fed in excess for six weeks before three sampling campaigns carried out successively to elucidate (i) the hepatic expression of selected genes involved in lipid, glucose and amino acid metabolism; (ii) the postprandial ammonia excretion; and (iii) the postprandial plasma methionine...

High-intensity laser for Ta and Ag implantation into different substrates for plasma diagnostics

Energy Technology Data Exchange (ETDEWEB)

Cutroneo, M., E-mail: cutroneo@ujf.cas.cz [Nuclear Physics Institute, AS CR, 25068 Rez (Czech Republic); Mackova, A.; Malinsky, P. [Nuclear Physics Institute, AS CR, 25068 Rez (Czech Republic); Department of Physics, Faculty of Science, J.E. Purkinje University, Ceske mladeze 8, 400 96 Usti nad Labem (Czech Republic); Matousek, J. [Department of Physics, Faculty of Science, J.E. Purkinje University, Ceske mladeze 8, 400 96 Usti nad Labem (Czech Republic); Torrisi, L. [Department of Physics and Earth Sciences, Messina University, V.le F.S. d’Alcontres 31, 98166 S. Agata, Messina (Italy); Ullschmied, J. [Institute of Physics, ASCR, v.v.i., 182 21 Prague 8 (Czech Republic)

2015-07-01

High-intensity lasers generating non-equilibrium plasma, can be employed to accelerate ions in the keV–MeV region, useful for many applications. In the present work, we performed study of ion implantation into different substrates by using a high-intensity laser at the PALS laboratory in Prague. Multi-energy ions generated by plasma from Ta and Ag targets were implanted into polyethylene and metallic substrates (Al, Ti) at energies of tens of keV per charge state. The ion emission was monitored online using time-of-flight detectors and electromagnetic deflection systems. Rutherford Backscattering Spectrometry (RBS) was used to characterise the elemental composition in the implanted substrates by ion plasma emission and to provide the implanted ion depth profiling. These last measurements enable offline plasma characterisation and provide information on the useful potentiality of multi-ion species and multi-energy ion implantation into different substrates. XPS analysis gives information on the chemical bonds and their modifications in the first superficial implanted layers. The depth distributions of implanted Ta and Ag ions were compared with the theoretical ones achieved by using the SRIM-2012 simulation code.

Implants in free fibula flap supporting dental rehabilitation - Implant and peri-implant related outcomes of a randomized clinical trial.

Science.gov (United States)

Kumar, Vinay V; Ebenezer, Supriya; Kämmerer, Peer W; Jacob, P C; Kuriakose, Moni A; Hedne, Naveen; Wagner, Wilfried; Al-Nawas, Bilal

2016-11-01

The objective of this study was to assess the difference in success rates of implants when using two or four implant-supported-overdentures following segmental mandibular reconstruction with fibula free flap. This prospective, parallel designed, randomized clinical study was conducted with 1:1 ratio. At baseline, all participants already had segmental reconstruction of mandible with free fibula flap. The participants were randomized into two groups: Group-I received implant-supported-overdentures on two tissue-level implants and Group-II received implant-supported-overdentures on four tissue-level implants. Success rates of the implants were evaluated at 3 months, 6 months and 12 months following implant loading using marginal bone level changes as well as peri-implant indices (Buser et al., 1990). 52 patients were randomized into two treatment groups (26 each), out of which 18 patients (36 implants) of Group-I and 17 patients (68 implants) of Group-II were evaluated. One implant in Group-I was lost due to infective complications and one patient in the same group had superior barrel necrosis. There was a statistically significant increase at both time points (p = 0.03, p = 0.04 at 6 months, 12 months) in the amount of marginal bone loss in Group-I (0.4 mm, 0.5 mm at 6 months, 12 months) as compared to Group-II (0.1 mm, 0.2 mm at 6 months, 12 months). There were no clinically significant changes peri-implant parameters between both groups. Peri-implant soft tissue hyperplasia was seen in both groups, 32% of implants at 3-months, 26% at 6-months and 3% at 12-months follow-up. The results of this study show that patients with 2-implant-supported-overdentures had higher marginal bone loss as compared to patients with 4-implant-supported-overdentures. There were no clinically significant differences in peri-implant soft tissue factors in patients with 2- or 4-implant-supported-overdentures. Hyperplastic peri-implant tissues are common in the early implant

Imaging of common breast implants and implant-related complications: A pictorial essay

Directory of Open Access Journals (Sweden)

Amisha T Shah

2016-01-01

Full Text Available The number of women undergoing breast implant procedures is increasing exponentially. It is, therefore, imperative for a radiologist to be familiar with the normal and abnormal imaging appearances of common breast implants. Diagnostic imaging studies such as mammography, ultrasonography, and magnetic resonance imaging are used to evaluate implant integrity, detect abnormalities of the implant and its surrounding capsule, and detect breast conditions unrelated to implants. Magnetic resonance imaging of silicone breast implants, with its high sensitivity and specificity for detecting implant rupture, is the most reliable modality to asses implant integrity. Whichever imaging modality is used, the overall aim of imaging breast implants is to provide the pertinent information about implant integrity, detect implant failures, and to detect breast conditions unrelated to the implants, such as cancer.

Effects of a glucokinase activator on hepatic intermediary metabolism: study with 13C-isotopomer-based metabolomics

OpenAIRE

Nissim, Itzhak; Horyn, Oksana; Nissim, Ilana; Daikhin, Yevgeny; Wehrli, Suzanne L.; Yudkoff, Marc; Matschinsky, Franz M.

2012-01-01

GKAs (glucokinase activators) are promising agents for the therapy of Type 2 diabetes, but little is known about their effects on hepatic intermediary metabolism. We monitored the fate of 13C-labelled glucose in both a liver perfusion system and isolated hepatocytes. MS and NMR spectroscopy were deployed to measure isotopic enrichment. The results demonstrate that the stimulation of glycolysis by GKA led to numerous changes in hepatic metabolism: (i) augmented flux through the TCA (tricarboxy...

Laboratory Investigation of Mineralization of Refractory Nitrogen from Sewage Treatment Plants.

Science.gov (United States)

Benoit, Gaboury; Wang, Peng

2017-12-01

Laboratory studies were conducted and modeled to evaluate whether refractory organic nitrogen in tertiary-treated wastewater effluent could become bioavailable by conversion to mineral forms. Multiday incubations of effluent collected from the Branford and New Haven, Connecticut, waste water treatment plants (WWTP) revealed low but steady conversion of organic nitrogen to nitrate (NO 3 - ). In Branford, the principal form of organic nitrogen was dissolved, and in New Haven it was particulate. Modeling suggested that in both the cases conversion to NO 3 - from organic forms occurred at several per cent per day, and appeared to happen via the intermediary NH 4 + . The results suggest that organic nitrogen may be an important source of bioavailable N, contributing to the problem of hypoxia in Long Island Sound and other estuaries.

Laboratory Investigation of Mineralization of Refractory Nitrogen from Sewage Treatment Plants

Science.gov (United States)

Benoit, Gaboury; Wang, Peng

2017-12-01

Laboratory studies were conducted and modeled to evaluate whether refractory organic nitrogen in tertiary-treated wastewater effluent could become bioavailable by conversion to mineral forms. Multiday incubations of effluent collected from the Branford and New Haven, Connecticut, waste water treatment plants (WWTP) revealed low but steady conversion of organic nitrogen to nitrate (NO3 -). In Branford, the principal form of organic nitrogen was dissolved, and in New Haven it was particulate. Modeling suggested that in both the cases conversion to NO3 - from organic forms occurred at several per cent per day, and appeared to happen via the intermediary NH4 +. The results suggest that organic nitrogen may be an important source of bioavailable N, contributing to the problem of hypoxia in Long Island Sound and other estuaries.

Retrograde peri-implantitis

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Mohamed Jumshad

2010-01-01

Full Text Available Retrograde peri-implantitis constitutes an important cause for implant failure. Retrograde peri-implantitis may sometimes prove difficult to identify and hence institution of early treatment may not be possible. This paper presents a report of four cases of (the implant placed developing to retrograde peri-implantitis. Three of these implants were successfully restored to their fully functional state while one was lost due to extensive damage. The paper highlights the importance of recognizing the etiopathogenic mechanisms, preoperative assessment, and a strong postoperative maintenance protocol to avoid retrograde peri-implant inflammation.

Surface-conductivity enhancement of PMMA by keV-energy metal-ion implantation

International Nuclear Information System (INIS)

Bannister, M.E.; Hijazi, H.; Meyer, H.M.; Cianciolo, V.; Meyer, F.W.

2014-01-01

An experiment has been proposed to measure the neutron electric dipole moment (nEDM) with high precision at the Oak Ridge National Laboratory (ORNL) Spallation Neutron Source. One of the requirements of this experiment is the development of PMMA (Lucite) material with a sufficiently conductive surface to permit its use as a high-voltage electrode while immersed in liquid He. At the ORNL Multicharged Ion Research Facility, an R and D activity is under way to achieve suitable surface conductivity in poly-methyl methacrylate (PMMA) using metal ion implantation. The metal implantation is performed using an electron-cyclotron-resonance (ECR) ion source and a recently developed beam line deceleration module that is capable of providing high flux beams for implantation at energies as low as a few tens of eV. The latter is essential for reaching implantation fluences exceeding 1 × 10 16 cm −2 , where typical percolation thresholds in polymers have been reported. In this contribution, we report results on initial implantation of Lucite by Ti and W beams with keV energies to average fluences in the range 0.5–6.2 × 10 16 cm −2 . Initial measurements of surface-resistivity changes are reported as function of implantation fluence, energy, and sample temperature. We also report X-ray photoelectron spectroscopy (XPS) surface and depth profiling measurements of the ion implanted samples, to identify possible correlations between the near surface and depth resolved implanted W concentrations and the measured surface resistivities

Brain Implants for Prediction and Mitigation of Epileptic Seizures - Final CRADA Report

Energy Technology Data Exchange (ETDEWEB)

Gopalsami, Nachappa

2016-09-29

This is a CRADA final report on C0100901 between Argonne National Laboratory and Flint Hills Scientific, LLC of Lawrence, Kansas. Two brain implantable probes, a surface acoustic wave probe and a miniature cooling probe, were designed, built, and tested with excellent results.

Enhanced antitumor efficacy of poly(D,L-lactide-co-glycolide-based methotrexate-loaded implants on sarcoma 180 tumor-bearing mice

Directory of Open Access Journals (Sweden)

Gao L

2017-10-01

Full Text Available Li Gao,1,2 Lunyang Xia,3 Ruhui Zhang,1 Dandan Duan,3 Xiuxiu Liu,2 Jianjian Xu,2 Lan Luo1 1State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 2School of Biological and Medical Engineering, Hefei University of Technology, Hefei, 3Laboratory of Pharmaceutical Research, Anhui Zhongren Science and Technology Co., Ltd., Hefei, People’s Republic of China Purpose: Methotrexate is widely used in chemotherapy for a variety of malignancies. However, severe toxicity, poor pharmacokinetics, and narrow safety margin of methotrexate limit its clinical application. The aim of this study was to develop sustained-release methotrexate-loaded implants and evaluate antitumor activity of the implants after intratumoral implantation. Materials and methods: We prepared the implants containing methotrexate, poly(D,L-lactide-co-glycolide, and polyethylene glycol 4000 with the melt-molding technique. The implants were characterized with regards to drug content, morphology, in vitro, and in vivo release profiles. Differential scanning calorimetry (DSC and Fourier transform infrared spectroscopy (FTIR were carried out to investigate the physicochemical properties of the implants. Furthermore, the antitumor activity of the implants was tested in a sarcoma 180 mouse model. Results: The implants were prepared as solid rods. Scanning electron microscopy images showed a smooth surface of the implant, suggesting that methotrexate was homogeneously dispersed in the polymeric matrix. The results of DSC and FTIR indicated that no significant interaction between methotrexate and the polymer was observed in the implants. Both in vitro and in vivo release profiles of the implants were characterized by burst release followed by sustained release of methotrexate. Intratumoral implantation of methotrexate-loaded implants could efficiently delay tumor growth. Moreover, an increase in the dose of implants led to a higher tumor

Safety and efficacy of Implanon, a single-rod implantable contraceptive containing etonogestrel.

Science.gov (United States)

Funk, Sidney; Miller, Michael M; Mishell, Daniel R; Archer, David F; Poindexter, Alfred; Schmidt, Juergen; Zampaglione, Edio

2005-05-01

The safety and efficacy of a single-rod implantable contraceptive containing etonogestrel (Implanontrade mark) were investigated in a multicenter clinical trial. Sexually active American women (N=330) with apparently normal menstrual cycles used the implant for up to 2 years. All subjects recorded bleeding and/or spotting daily in a diary. Safety was assessed through adverse experiences (AEs), laboratory tests and physical and gynecologic examinations. Total exposure was 474 woman-years (6186 cycles), and 68% of subjects had at least 1 year of exposure. No pregnancies occurred. The most common bleeding pattern observed throughout the study was infrequent bleeding, defined as less than three episodes of bleeding in a reference period (excluding amenorrhea). The least common pattern was frequent bleeding, defined as more than five episodes of bleeding in a reference period. Infrequent, prolonged and frequent bleeding patterns were most common early in the study and declined thereafter. During the 3-month Reference Periods 2-8 (Months 4-24), the incidence of amenorrhea ranged from 14% to 20%. Forty-three subjects (13%) withdrew from the study because of bleeding pattern changes and 76 subjects (23%) discontinued because of other AEs. Other common AEs leading to discontinuation, besides bleeding irregularities, were emotional lability (6.1%), weight increase (3.3%), depression (2.4%) and acne (1.5%). Use of Implanon (etonogestrel subdermal implant, referred to herein as ENG implant) for up to 2 years had no clinically significant effects on laboratory parameters, physical and pelvic examinations, vital signs or body mass index. The average length of time required for ENG implant insertion and that for removal were 0.5 and 3.5 min, respectively, and all the procedures were uncomplicated. The return to normal menstrual cycles and fertility was rapid after removal. Implanon is a safe, highly effective and rapidly reversible new method of contraception.

Cochlear implants in children implanted in Jordan: A parental overview.

Science.gov (United States)

Alkhamra, Rana A

2015-07-01

Exploring the perspective of parents on the cochlear implant process in Jordan. Sixty parents of deaf children were surveyed on the information gathering process prior to cochlear implant surgery, and their implant outcome expectations post-surgery. Whether child or parent characteristics may impact parents' post-surgical expectations was explored. Although parents used a variety of information sources when considering a cochlear implant, the ear, nose and throat doctor comprised their major source of information (60%). Parents received a range of information prior to cochlear implant but agreed (93.3%) on the need for a multidisciplinary team approach. Post-surgically, parents' expected major developments in the areas of spoken language (97%), and auditory skills (100%). Receiving education in mainstream schools (92%) was expected too. Parents perceived the cochlear implant decision as the best decision they can make for their child (98.3%). A significant correlation was found between parents contentment with the cochlear implant decision and expecting developments in the area of reading and writing (r=0.7). Child's age at implantation and age at hearing loss diagnosis significantly affected parents' post-implant outcome expectations (pparents agree on the need for a comprehensive multidisciplinary team approach during the different stages of the cochlear implant process. Parents' education about cochlear implants prior to the surgery can affect their post-surgical outcome expectations. The parental perspective presented in this study can help professionals develop better understanding of parents' needs and expectations and henceforth improve their services and support during the different stages of the cochlear implant process. Copyright © 2015. Published by Elsevier Ireland Ltd.

Long time follow up of implant therapy and treatment of peri-implantitis.

Science.gov (United States)

Roos-Jansåker, Ann-Marie

2007-01-01

Dental implants have become an often used alternative to replace missing teeth, resulting in an increasing percentage of the adult population with implant supported prosthesis. Although favourable long-term results of implant therapy have been reported, infections occur. Until recently few reports included data on peri-implant infections, possibly underestimating this complication of implant treatment. It is possible that some infections around implants develop slowly and that with time peri-implantitis will be a common complication to implant therapy as an increasing number of patients have had their implants for a long time (>10 years). Data on treatment of peri-implant lesions are scarce leaving the clinician with limited guidance regarding choice of treatment. The aim of this thesis was to study the frequency of implant loss and presence of peri-implant lesions in a group of patients supplied with Brånemark implants 9-14 years ago, and to relate these events to patient and site specific characteristics. Moreover three surgical treatment modalities for peri-implantitis were evaluated. The thesis is based on six studies; Studies I-III included 218 patients and 1057 implants followed for 9-14 years evaluating prevalence of, and factors related to implant loss (Paper I) and prevalence of peri-implant infections and related factors (Paper I-III). Study IV is a review describing different treatment modalities of peri-implant infections. Study V is a prospective cohort study involving 36 patients and 65 implants, evaluating the use of a bone substitute with or without the use of a resorbable membrane. Study VI is a case series with 12 patients and 16 implants, evaluating a bone substitute in combination with a resorbable membrane and submerged healing. This thesis demonstrated that: After 9-14 years the survival rates of dental implants are high (95.7%). Implant loss seems to cluster within patients and are related to periodontitis evidenced as bone loss on

Hip Implant Systems

Science.gov (United States)

... Implants and Prosthetics Metal-on-Metal Hip Implants Hip Implants Share Tweet Linkedin Pin it More sharing options Linkedin Pin it Email Print Hip implants are medical devices intended to restore mobility ...

A new nuclear materials laboratory at Queen's University

Energy Technology Data Exchange (ETDEWEB)

Holt, R.A.; Daymond, M.R., E-mail: holt@queensu.ca, E-mail: daymond@queensu.ca [Queen' s University, Department of Mechanical and Materials Engineering, Kingston, ON (Canada)

2015-07-01

The Reactor Materials Testing Laboratory (RMTL) at Queen's University and the results of commissioning tests are described. RMTL uses energetic protons (up to 8MeV) to simulate fast neutron damage in materials for reactor components. The laboratory is also capable of He implantation (up to 12 MeV) to simulate the effects of transmutation He in reactor components. The $17.5M laboratory comprises a new building, a 4MV tandem accelerator, two electron microscopes, mechanical testing and specimen preparation equipment, and a radiation detection laboratory. RMTL focusses on studying dynamic effects of irradiation (irradiation creep, irradiation growth, irradiation induced swelling, fatigue under irradiation) in-situ. (author)

Age at implantation and auditory memory in cochlear implanted children.

Science.gov (United States)

Mikic, B; Miric, D; Nikolic-Mikic, M; Ostojic, S; Asanovic, M

2014-05-01

Early cochlear implantation, before the age of 3 years, provides the best outcome regarding listening, speech, cognition an memory due to maximal central nervous system plasticity. Intensive postoperative training improves not only auditory performance and language, but affects auditory memory as well. The aim of this study was to discover if the age at implantation affects auditory memory function in cochlear implanted children. A total of 50 cochlear implanted children aged 4 to 8 years were enrolled in this study: early implanted (1-3y) n = 27 and late implanted (4-6y) n = 23. Two types of memory tests were used: Immediate Verbal Memory Test and Forward and Backward Digit Span Test. Early implanted children performed better on both verbal and numeric tasks of auditory memory. The difference was statistically significant, especially on the complex tasks. Early cochlear implantation, before the age of 3 years, significantly improve auditory memory and contribute to better cognitive and education outcomes.

Breast reconstruction - implants

Science.gov (United States)

Breast implants surgery; Mastectomy - breast reconstruction with implants; Breast cancer - breast reconstruction with implants ... harder to find a tumor if your breast cancer comes back. Getting breast implants does not take as long as breast reconstruction ...

Triangulating the Position of Antimony Donors Implanted in Silicon

Science.gov (United States)

Bureau-Oxton, Chloe; Nielsen, Erik; Luhman, Dwight; Ten Eyck, Gregory; Pluym, Tammy; Wendt, Joel; Pioro-Ladrière, Michel; Lilly, Michael; Carroll, Malcolm

2015-03-01

A potential candidate for a quantum bit is a single Sb atom implanted in silicon. A single-electron-transistor (SET) situated close to an Sb donor can be used to measure the occupancy and spin of the electron on the donor while the lithographically patterned poly-silicon gates defining the SET can be used to control donor occupancy. In our samples two clusters of Sb donors have been implanted adjacent to opposite sides of the SET through a self-aligned process. In this talk, we will present experimental results that allow us to determine the approximate position of different donors by determining their relative capacitance to pairs of the SET's poly-silicon gates. We will present the results of capacitive-based modeling calculations that allow us to further locate the position of the donors. This work was performed, in part, at the Center for Integrated Nanotechnologies, a U.S. DOE Office of Basic Energy Sciences user facility. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a Lockheed-Martin Company, for the U. S. Department of Energy under Contract No. DE-AC04-94AL85000.

Precision of fit between implant impression coping and implant replica pairs for three implant systems.

Science.gov (United States)

Nicoll, Roxanna J; Sun, Albert; Haney, Stephan; Turkyilmaz, Ilser

2013-01-01

The fabrication of an accurately fitting implant-supported fixed prosthesis requires multiple steps, the first of which is assembling the impression coping on the implant. An imprecise fit of the impression coping on the implant will cause errors that will be magnified in subsequent steps of prosthesis fabrication. The purpose of this study was to characterize the 3-dimensional (3D) precision of fit between impression coping and implant replica pairs for 3 implant systems. The selected implant systems represent the 3 main joint types used in implant dentistry: external hexagonal, internal trilobe, and internal conical. Ten impression copings and 10 implant replicas from each of the 3 systems, B (Brånemark System), R (NobelReplace Select), and A (NobelActive) were paired. A standardized aluminum test body was luted to each impression coping, and the corresponding implant replica was embedded in a stone base. A coordinate measuring machine was used to quantify the maximum range of displacement in a vertical direction as a function of the tightening force applied to the guide pin. Maximum angular displacement in a horizontal plane was measured as a function of manual clockwise or counterclockwise rotation. Vertical and rotational positioning was analyzed by using 1-way analysis of variance (ANOVA). The Fisher protected least significant difference (PLSD) multiple comparisons test of the means was applied when the F-test in the ANOVA was significant (α=.05). The mean and standard deviation for change in the vertical positioning of impression copings was 4.3 ±2.1 μm for implant system B, 2.8 ±4.2 μm for implant system R, and 20.6 ±8.8 μm for implant system A. The mean and standard deviation for rotational positioning was 3.21 ±0.98 degrees for system B, 2.58 ±1.03 degrees for system R, and 5.30 ±0.79 degrees for system A. The P-value for vertical positioning between groups A and B and between groups A and R was <.001. No significant differences were found for

Assessing Borrower's and Business' Factors Causing Microcredit Default in Kenya: A Comparative Analysis of Microfinance Institutions and Financial Intermediaries

Science.gov (United States)

Muthoni, Muturi Phyllis

2016-01-01

A major concern on microcredit repayment remains a major obstacle to the Micro Financial Institutions (MFIs) and Financial Intermediaries (FIs) in Kenya. The health of MFI sector in Sub Sahara Africa (SSA) is a cause of concern due to the increased portfolio at risk (PAR). This region records the highest risk globally. Its PAR 30 is greater than 5…

Ion implantation

International Nuclear Information System (INIS)

Johnson, E.

1986-01-01

It is the purpose of the present paper to give a review of surface alloy processing by ion implantation. However, rather than covering this vast subject as a whole, the survey is confined to a presentation of the microstructures that can be found in metal surfaces after ion implantation. The presentation is limited to alloys processed by ion implantation proper, that is to processes in which the alloy compositions are altered significantly by direct injection of the implanted ions. The review is introduced by a presentation of the processes taking place during development of the fundamental event in ion implantation - the collision cascade, followed by a summary of the various microstructures which can be formed after ion implantation into metals. This is compared with the variability of microstructures that can be achieved by rapid solidification processing. The microstructures are subsequently discussed in the light of the processes which, as the implantations proceed, take place during and immediately after formation of the individual collision cascades. These collision cascades define the volumes inside which individual ions are slowed down in the implanted targets. They are not only centres for vigorous agitation but also the sources for formation of excess concentrations of point defects, which will influence development of particular microstructures. A final section presents a selection of specific structures which have been observed in different alloy systems. (orig./GSCH)

Does the number of implants have any relation with peri-implant disease?

Directory of Open Access Journals (Sweden)

Bernardo Born PASSONI

2014-10-01

Full Text Available Objective: The aim of this study was to evaluate the relationship between the number of pillar implants of implant-supported fixed prostheses and the prevalence of periimplant disease. Material and Methods: Clinical and radiographic data were obtained for the evaluation. The sample consisted of 32 patients with implant-supported fixed prostheses in function for at least one year. A total of 161 implants were evaluated. Two groups were formed according to the number of implants: G1 ≤5 implants and G2 >5 implants. Data collection included modified plaque index (MPi, bleeding on probing (BOP, probing depth (PD, width of keratinized mucosa (KM and radiographic bone loss (BL. Clinical and radiographic data were grouped for each implant in order to conduct the diagnosis of mucositis or peri-implantitis. Results: Clinical parameters were compared between groups using Student’s t test for numeric variables (KM, PD and BL and Mann-Whitney test for categorical variables (MPi and BOP. KM and BL showed statistically significant differences between both groups (p<0.001. Implants from G1 – 19 (20.43% – compared with G2 – 26 (38.24% – showed statistically significant differences regarding the prevalence of peri-implantitis (p=0.0210. Conclusion: It seems that more than 5 implants in total fixed rehabilitations increase bone loss and consequently the prevalence of implants with periimplantitis. Notwithstanding, the number of implants does not have any influence on the prevalence of mucositis.

Social support and social network as intermediary social determinants of dental caries in adolescents.

Science.gov (United States)

Fontanini, Humberto; Marshman, Zoe; Vettore, Mario

2015-04-01

The aim of this study was to investigate the association between intermediary social determinants, namely social support and social network with dental caries in adolescents. An adapted version of the WHO social determinants of health conceptual framework was used to organize structural and intermediary social determinants of dental caries into six blocks including perceived social support and number of social networks. A cross-sectional study was conducted with a representative sample of 542 students between 12 and 14 years of age in public schools located in the city of Dourados, Brazil in 2012. The outcome variables were caries experience (DMFT ≥ 1) and current dental caries (component D of DMFT ≥ 1) recorded by a calibrated dentist. Individual interviews were performed to collect data on perceived social support and numbers of social networks from family and friends and covariates. Multivariate Poisson regressions using hierarchical models were conducted. The prevalence of adolescents with caries experience and current dental caries was 55.2% and 32.1%, respectively. Adolescents with low numbers of social networks and low levels of social support from family (PR 1.47; 95% CI = 1.01-2.14) were more likely to have DMFT ≥ 1. Current dental caries was associated with low numbers of social networks and low levels of social support from family (PR 2.26; 95% CI = 1.15-4.44). Social support and social network were influential psychosocial factors to dental caries in adolescents. This finding requires confirmation in other countries but potentially has implications for programmes to promote oral health. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Tribological properties of nitrogen implanted and boron implanted steels

International Nuclear Information System (INIS)

Kern, K.T.

1996-01-01

Samples of a steel with high chrome content was implanted separately with 75 keV nitrogen ions and with 75 keV boron ions. Implanted doses of each ion species were 2-, 4-, and 8 x 10 17 /cm 2 . Retained doses were measured using resonant non-Rutherford Backscattering Spectrometry. Tribological properties were determined using a pin-on-disk test with a 6-mm diameter ruby pin with a velocity of 0.94 m/min. Testing was done at 10% humidity with a load of 377 g. Wear rate and coefficient of friction were determined from these tests. While reduction in the wear rate for nitrogen implanted materials was observed, greater reduction (more than an order of magnitude) was observed for boron implanted materials. In addition, reduction in the coefficient of friction for high-dose boron implanted materials was observed. Nano-indentation revealed a hardened layer near the surface of the material. Results from grazing incidence x-ray diffraction suggest the formation of Fe 2 N and Fe 3 N in the nitrogen implanted materials and Fe 3 B in the boron implanted materials. Results from transmission electron microscopy will be presented

Cochlear implantation in late-implanted adults with prelingual deafness.

Science.gov (United States)

Most, Tova; Shrem, Hadas; Duvdevani, Ilana

2010-01-01

The purpose of this study was to examine the effect of cochlear implantation (CI) on prelingually deafened participants who were implanted as adults. The effect of the CI was examined with regard to the following variables: communication, family, social skills, education, and work satisfaction with one's life, loneliness, and self-esteem. Thirty-eight adults participated. Four self-report questionnaires were used at 2 points in time: before and after CI. The research findings show significant differences in the reports of most variables before and after implantation. The participants felt better with regard to communication, social skills, education, and work and satisfaction with one's life after implantation in comparison to their feelings before implantation. Furthermore, they felt less lonely after implantation. However, there were no significant differences before and after implantation regarding their feelings within the family and regarding their self-esteem. The results demonstrated the need to evaluate the benefits resulting from the CI not only with traditional clinical measures but with additional measures as well. Furthermore, they demonstrated the benefit of the CI on the positive psychosociological implications of prelingually deafened adults. Copyright © 2010 Elsevier Inc. All rights reserved.

Histology of a dental implant with a platform switched implant-abutment connection

Directory of Open Access Journals (Sweden)

Vittoria Perrotti

2011-10-01

Full Text Available Background: Peri-implant crestal bone must be stable for aesthetic reasons. Aim of this study was a histologic analysis of an implant with a platform switched implant-abutment connection. Materials and methods: A 32-year-old male patient participated in this study. The patient needed a bilateral mandibular restoration. Four implants were used, and were immediately restored and loaded the same day of insertion. After a 6 weeks healing period, one implant with platform-switched abutment was retrieved with trephine. Before retrieval the implant was osseointegrated and not mobile. On one side of the implant, a 1 mm resorption of the crestal bone was present. On the contrary, on the other side no bone resorption had occurred and about 1 mm of bone was present over the implant shoulder. Results: The bone-implant contact percentage was 65.1 ± 6.3 %. Platform- switching could help in maintaining the height of the peri-implant crestal bone.

Effectiveness of Implant Therapy Analyzed in a Swedish Population: Prevalence of Peri-implantitis.

Science.gov (United States)

Derks, J; Schaller, D; Håkansson, J; Wennström, J L; Tomasi, C; Berglundh, T

2016-01-01

Peri-implantitis is an inflammatory disease affecting soft and hard tissues surrounding dental implants. As the global number of individuals that undergo restorative therapy through dental implants increases, peri-implantitis is considered as a major and growing problem in dentistry. A randomly selected sample of 588 patients who all had received implant-supported therapy 9 y earlier was clinically and radiographically examined. Prevalence of peri-implantitis was assessed and risk indicators were identified by multilevel regression analysis. Forty-five percent of all patients presented with peri-implantitis (bleeding on probing/suppuration and bone loss >0.5 mm). Moderate/severe peri-implantitis (bleeding on probing/suppuration and bone loss >2 mm) was diagnosed in 14.5%. Patients with periodontitis and with ≥4 implants, as well as implants of certain brands and prosthetic therapy delivered by general practitioners, exhibited higher odds ratios for moderate/severe peri-implantitis. Similarly, higher odds ratios were identified for implants installed in the mandible and with crown restoration margins positioned ≤1.5 mm from the crestal bone at baseline. It is suggested that peri-implantitis is a common condition and that several patient- and implant-related factors influence the risk for moderate/severe peri-implantitis (ClinicalTrials.gov NCT01825772). © International & American Associations for Dental Research 2015.

Plasma-sprayed titanium coating to polyetheretherketone improves the bone-implant interface.

Science.gov (United States)

Walsh, William R; Bertollo, Nicky; Christou, Chrisopher; Schaffner, Dominik; Mobbs, Ralph J

2015-05-01

Rapid and stable fixation at the bone-implant interface would be regarded as one of the primary goals to achieve clinical efficacy, regardless of the surgical site. Although mechanical and physical properties of polyetheretherketone (PEEK) provide advantages for implant devices, the hydrophobic nature and the lack of direct bone contact remains a limitation. To examine the effects of a plasma-sprayed titanium coated PEEK on the mechanical and histologic properties at the bone-implant interface. A preclinical laboratory study. Polyetheretherketone and plasma-sprayed titanium coated PEEK implants (Ti-bond; Spinal Elements, Carlsbad, CA, USA) were placed in a line-to-line manner in cortical bone and in a press-fit manner in cancellous bone of adult sheep using an established ovine model. Shear strength was assessed in the cortical sites at 4 and 12 weeks, whereas histology was performed in cortical and cancellous sites at both time points. The titanium coating dramatically improved the shear strength at the bone-implant interface at 4 weeks and continued to improve with time compared with PEEK. Direct bone ongrowth in cancellous and cortical sites can be achieved using a plasma-sprayed titanium coating on PEEK. Direct bone to implant bonding can be achieved on PEEK in spite of its hydrophobic nature using a plasma-sprayed titanium coating. The plasma-sprayed titanium coating improved mechanical properties in the cortical sites and the histology in cortical and cancellous sites. Copyright © 2015 Elsevier Inc. All rights reserved.

Bilateral Poly Implant Prothèse Implant Rupture: An Uncommon Presentation

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Peter Mallon

2013-07-01

Full Text Available Summary: A woman in her 50s underwent delayed bilateral Poly Implant Prothèse implant reconstruction following mastectomy for breast cancer. Symptoms of implant rupture developed 43 months after surgery with an erythematous rash on her trunk. The rash then spread to her reconstructed breast mounds. Initial ultrasound scan and magnetic resonance imaging were normal; however, subsequent magnetic resonance imaging demonstrated left implant rupture only. In theater, following removal of both implants, both were found to be ruptured. The rash on her trunk resolved within 3 weeks in the postoperative period. Chemical analyses of silicone in both implants confirmed a nonauthorized silicone source; in addition, the chemical structure was significantly different between the left and right implant, perhaps explaining the variation in presentation.

Complications after cardiac implantable electronic device implantations

DEFF Research Database (Denmark)

Kirkfeldt, Rikke Esberg; Johansen, Jens Brock; Nohr, Ellen Aagaard

2013-01-01

Complications after cardiac implantable electronic device (CIED) treatment, including permanent pacemakers (PMs), cardiac resynchronization therapy devices with defibrillators (CRT-Ds) or without (CRT-Ps), and implantable cardioverter defibrillators (ICDs), are associated with increased patient...

Management of peri-implantitis

Directory of Open Access Journals (Sweden)

Jayachandran Prathapachandran

2012-01-01

Full Text Available Peri-implantitis is a site-specific infectious disease that causes an inflammatory process in soft tissues, and bone loss around an osseointegrated implant in function. The etiology of the implant infection is conditioned by the status of the tissue surrounding the implant, implant design, degree of roughness, external morphology, and excessive mechanical load. The microorganisms most commonly associated with implant failure are spirochetes and mobile forms of Gram-negative anaerobes, unless the origin is the result of simple mechanical overload. Diagnosis is based on changes of color in the gingiva, bleeding and probing depth of peri-implant pockets, suppuration, X-ray, and gradual loss of bone height around the tooth. Treatment will differ depending upon whether it is a case of peri-implant mucositis or peri-implantitis. The management of implant infection should be focused on the control of infection, the detoxification of the implant surface, and regeneration of the alveolar bone. This review article deals with the various treatment options in the management of peri-implantitis. The article also gives a brief description of the etiopathogenesis, clinical features, and diagnosis of peri-implantitis.

Maxillary and mandibular immediately loaded implant-supported interim complete fixed dental prostheses on immediately placed dental implants with a digital approach: A clinical report.

Science.gov (United States)

Lewis, Ryan C; Harris, Bryan T; Sarno, Robert; Morton, Dean; Llop, Daniel R; Lin, Wei-Shao

2015-09-01

This clinical report describes the treatment of maxillary and mandibular immediate implant placement and immediately loaded implant-supported interim complete fixed dental prostheses with a contemporary digital approach. The virtual diagnostic tooth arrangement eliminated the need for a customized radiographic template, and the diagnostic data collection required for computer-guided surgery (digital diagnostic impressions, digital photographs, and a cone beam-computed tomography [CBCT] scan) was completed in a single visit with improved workflow efficiency. Computer-aided design and computer-aided manufacturing (CAD/CAM)-fabricated surgical templates and interim prosthesis templates were made in a dental laboratory to facilitate computer-guided surgery and the immediate loading process. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Experimental study on bone tissue reaction around HA implants radiated after implantation

International Nuclear Information System (INIS)

Kudo, Masato; Matsui, Yoshiro; Tamura, Sayaka; Chen, Xuan; Uchida, Haruo; Mori, Kimie; Ohno, Kohsuke; Michi, Ken-ichi

1998-01-01

This study was conducted to investigate histologically and histomorphometrically the tissue reaction around hydroxylapatite (HA) implants that underwent irradiation in 3 different periods in the course of bone healing after implantation. The cylindrical high-density HA implants were implanted in 48 Japanese white rabbit mandibles. A single 15 Gy dose was applied to the mandible 5, 14, or 28 days after implantation. The rabbits were sacrificed 7, 14, 28, and 90 days after irradiation. Nonirradiated rabbits were used as controls. CMR, labeling with tetracycline and calcein, and non-decalcified specimens stained with toluidine blue were used for histological analyses and histomorphometric measurements. The results were as follows: In the rabbits irradiated 5 days after implantation, the HA-bone contact was observed later than that in the controls and the bone-implant contact surface ratio was lower than that in the controls at examination because necrosis of the newly-formed bone occurred just after irradiation. HA-bone contact of the rabbits irradiated 14 and 28 days after implantation was similar to that of the controls. And, bone remodeling was suppressed in rabbits of each group sacrificed at 90 days after irradiation. The results suggested that a short interval between implantation and irradiation causes direct contact between HA implant and bone and a long lapse of time before irradiation hardly affects the bone-implant contact, but delays bone remodeling. Therefore, it is necessary to prevent overloading the HA implants irradiated after implantation and pay utmost attention to conditions around the bone-implant contact. (author)

One-stage explant-implant procedure of exposed porous orbital implants

DEFF Research Database (Denmark)

Toft, Peter B; Rasmussen, Marie L Roed; Prause, Jan Ulrik

2011-01-01

Purpose:  To investigate the risks of implant exposure after a combined explant-implant procedure in patients with an exposed porous orbital implant. Methods:  Twenty-four consecutive patients who had a combined explant-implant procedure of an exposed hydroxyapatite (21) or porous polyethylene (3...... at the same procedure in sockets without profound signs of infection. The procedure carries a possible risk of poor motility....

Two-stage implant systems.

Science.gov (United States)

Fritz, M E

1999-06-01

Since the advent of osseointegration approximately 20 years ago, there has been a great deal of scientific data developed on two-stage integrated implant systems. Although these implants were originally designed primarily for fixed prostheses in the mandibular arch, they have been used in partially dentate patients, in patients needing overdentures, and in single-tooth restorations. In addition, this implant system has been placed in extraction sites, in bone-grafted areas, and in maxillary sinus elevations. Often, the documentation of these procedures has lagged. In addition, most of the reports use survival criteria to describe results, often providing overly optimistic data. It can be said that the literature describes a true adhesion of the epithelium to the implant similar to adhesion to teeth, that two-stage implants appear to have direct contact somewhere between 50% and 70% of the implant surface, that the microbial flora of the two-stage implant system closely resembles that of the natural tooth, and that the microbiology of periodontitis appears to be closely related to peri-implantitis. In evaluations of the data from implant placement in all of the above-noted situations by means of meta-analysis, it appears that there is a strong case that two-stage dental implants are successful, usually showing a confidence interval of over 90%. It also appears that the mandibular implants are more successful than maxillary implants. Studies also show that overdenture therapy is valid, and that single-tooth implants and implants placed in partially dentate mouths have a success rate that is quite good, although not quite as high as in the fully edentulous dentition. It would also appear that the potential causes of failure in the two-stage dental implant systems are peri-implantitis, placement of implants in poor-quality bone, and improper loading of implants. There are now data addressing modifications of the implant surface to alter the percentage of

資訊檢索指導員評鑑量表之探討 A Study of Evaluation Checklist on the Performance of Information Intermediaries

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Shih-hsion Huang

1998-09-01

Full Text Available 無The main purpose of this study is to induce important factors of a good performance of information intermediaries by developing the evaluation checklist. By employing the Delphi Method, first step is to collect Delphi panel's (people who are/were in charge of reference and information services in university libraries opinions by open questionnaire. Upon them, a constructive questionnaire is developed and sent out to experts to rank on the degree of importance of evaluation items. A final consensus among the experts is gotten in the second round of Delphi process. An evaluation checklist of information intermediaries is established based on the study result. According the result of the study, the final evaluation checklist comprised seven parts with 191 items totally. That can be a reference to related fields and following researches.

Van de Graaff Laboratory progress report [1974

International Nuclear Information System (INIS)

Bhatia, M.S.

1977-01-01

Research and development work carried out in the Van de Graaff Laboratory of the Bhabha Atomic Research Centre, Bombay, India during 1974 has been reported. Research programmes in the field of nuclear reactions and activities of the Indian Nuclear Data Group are described. Progress of developmental work on the low energy horizontal tandem accelerator, Dumas mass separator and ion implantation facility is reported. (K.M.)

Impact of implant design on primary stability of orthodontic mini-implants.

Science.gov (United States)

Wilmes, Benedict; Ottenstreuer, Stephanie; Su, Yu-Yu; Drescher, Dieter

2008-01-01

Skeletal anchorage with mini-implants has greatly broadened the treatment possibilities in orthodontics over the last few years. To reduce implant failure rates, it is advisable to obtain adequate primary stability. The aim of this study was to quantitatively analyze the impact of implant design and dimension on primary stability. Forty-two porcine iliac bone segments were prepared and embedded in resin. To evaluate the primary stability, we documented insertion torques of the following mini-implants: Aarhus Screw, AbsoAnchor, LOMAS, Micro-Anchorage-System, ORLUS and Spider Screw. In each bone, five Dual Top Screws were inserted for reference purposes to achieve comparability among the specimens. We observed wide variation in insertion torques and hence primary stability, depending on mini-implant design and dimension; the great impact that mini-implant diameter has on insertion torques was particularly conspicuous. Conical mini-implants achieved higher primary stabilities than cylindrical designs. The diameter and design of the mini-implant thread have a distinctive impact on primary stability. Depending on the region of insertion and local bone quality, the choice of the mini-implant design and size is crucial to establish sufficient primary stability.

Effect of implant position, angulation, and attachment height on peri-implant bone stress associated with mandibular two-implant overdentures: a finite element analysis.

Science.gov (United States)

Hong, Hae Ryong; Pae, Ahran; Kim, Yooseok; Paek, Janghyun; Kim, Hyeong-Seob; Kwon, Kung-Rock

2012-01-01

The aim of this study was to analyze and compare the level and distribution of peri-implant bone stresses associated with mandibular two-implant overdentures with different implant positions. Mathematical models of mandibles and overdentures were designed using finite element analysis software. Two intraosseous implants and ball attachment systems were placed in the interforaminal region. The overdenture, which was supported by the two implants, was designed to withstand bilateral and unilateral vertical masticatory loads (total 100 N). In all, eight types of models, which differed according to assigned implant positions, height of attachments, and angulation, were tested: MI (model with implants positioned in the lateral incisor sites), MC (implants in canine sites), MP (implants in premolar sites), MI-Hi (greater height of attachments), MC-M (canine implants placed with mesial inclination), MC-D (canine implants placed with distal inclination), MC-B (canine implants placed with buccal inclination), and MC-L (canine implants placed with lingual inclination). Peri-implant bone stress levels associated with overdentures retained by lateral incisor implants resulted in the lowest stress levels and the highest efficiency in distributing peri-implant stress. MI-Hi showed increased stress levels and decreased efficiency in stress distribution. As the implants were inclined, stress levels increased and the efficiency of stress distribution decreased. Among the inclined models, MC-B showed the lowest stress level and best efficiency in stress distribution. The lowest stress and the best stability of implants in mandibular two-implant overdentures were obtained when implants were inserted in lateral incisor areas with shorter attachments and were placed parallel to the long axes of the teeth.

Intermediaries and the Framing of Use-Practices in Design-Use Relations

DEFF Research Database (Denmark)

, and of use, various network elements are in flux, serving at times as ‘intermediaries’ (here used in the delimited Actor-Network sense) and other times, as ‘actants’ in networks of relations. The paper grapples with the issue by drawing upon two delimited case studies, dealing with ‘public access...... by authorities and/or organizations seeking to strengthen life-saving efforts for victims of cardiac arrest in public settings, particular focus on this case is the situation in Denmark, where legislation paved the way for making the devices available to the general public. Some other countries have instead......-presentation (Law 2002, Cooper 2005). The relevance of intermediaries for design is addressed, where the cases in point show how aspects of use, and hereby the role of users and use-practices, are implicated and distributed through enactments in the heterogeneous orderings and networks of relations in design...

Implantation of β-emitters on biomedical implants: 32 P isotropic ion implantation using a coaxial plasma reactor

International Nuclear Information System (INIS)

Fortin, M.A.; Paynter, R.W.; Sarkissian, A.; Stansfield, B.L.; Terreault, B.; Dufresne, V.

2003-01-01

The development of endovascular brachytherapy and the treatment of certain types of cancers (liver, lung, prostate) often require the use of beta-emitters, sometimes in the form of radioisotope-implanted devices. Among the most commonly used isotopes figures 32 P, a pure beta-emitter (maximum energy: 1.7 MeV), of which the path in biological tissues is of a few cm, restricting the impact of electron bombardment to the immediate environment of the implant. Several techniques and processes have been tried to elaborate surfaces and devices showing strongly bonded, or implanted 32 P. Anodizing, vapor phase deposition, grafting of oligonucleotides, as well as ion implantation processes have been investigated by several research groups as methods to implant beta-radioisotopes into surfaces. A coaxial plasma reactor was developed at INRS to implant radioisotopes into cylindrical metallic objects, such as coronary stents commonly used in angioplasty procedures. The dispersion of 32 P atoms on the interior surfaces of the chamber can be investigated using radiographs, contributing to image the plasma ion transport mechanisms that guide the efficiency of the implantation procedure. The amount of radioactivity on the wall liner, on the internal components, and on the biomedical implants are quantified using a surface barrier detector. A comparative study establishes a relationship between the gray scale of the radiographs, and dose measurements. A program was developed to convert the digitized images into maps showing surface dose density in mCi/cm 2 . An integration process allows the quantification of the doses on the walls and components of the reactor. Finally, the resulting integral of the 32 P dose is correlated to the initial amount of radioactivity inserted inside the implanter before the dismantling procedure. This method could be introduced as a fast and reliable way to test, qualify and assess the amount of radioactivity present on the as-produced implants

Limitations of using micro-computed tomography to predict bone-implant contact and mechanical fixation.

Science.gov (United States)

Liu, S; Broucek, J; Virdi, A S; Sumner, D R

2012-01-01

zone in the OV/TV program to avoid metal-induced artefacts with the scanner used in this study means that it is not possible to make bone measurements sufficiently close to the implant surface to obtain an accurate assessment of BIC. Current generation laboratory-based μCT scanners typically have voxel sizes of 6-8 μm or larger which will still not overcome this limitation. Thus, peri-implant bone measurements at these resolutions should only be used as a guide to predict implant fixation and should not be over-interpreted as a measurement of BIC. Newer generation laboratory-based μCT scanners have several improvements including better spatial resolution and X-ray sources and appear to have less severe metal-induced artefacts, but will need appropriate validation as they become available to researchers. Regardless of the μCT scanner being used, we recommend that detailed validation studies be performed for any study using metal implants because variation in the composition and geometry of the particular implants used may lead to different artefact patterns. © 2011 The Authors Journal of Microscopy © 2011 Royal Microscopical Society.

Complex diagnosis in dental implantation and potentialities of predicting the results of treatment

International Nuclear Information System (INIS)

Matveeva, A.I.; Kulakov, A.A.

1995-01-01

Experience gained by the implantation Department of Central Research Institute of Dentistry in many years showed that comprehensive clinical and laboratory examinations, including roentgenological examination, functional diagnosis and examination of the immunity system help detect all unfavorable local and general factors. In patients referred to the risk group implantation is possible after preoperative treatment. Designing of STOM-1 and STOM-2, as well as of UMR-1 software helped carry our the calculations using IBM PC and determine the optimal type of the graft, place of its introduction, and number of grafts, as well as calculate the optimal design of the prosthesis

Contact of dual mobility implants: effects of cup wear and inclination.

Science.gov (United States)

Uddin, M S

2015-01-01

Cup wear and inclination on the pelvic bone are significant factors, which change the contact of the articulating surfaces, thus, impacting the long-term performance of hip implants. This paper presents a finite element (FE) analysis of the contact of the dual mobility implants under the influence of cup wear and inclination. A 3D FE model of the implant was developed with the application of equivalent physiological loading and boundary conditions. Effects of cup inclination angle ranging from 45° to 60° and the wear depth ranging from 0 to 2.46 mm equivalent to up to 30 years of the implant's life on the contact pressure and von Mises stress were investigated. Simulation results show that the contact pressure and von Mises stress decrease significantly with a modest wear depth and remains quite in-sensitive to the cup inclination angle and wear depth up to 1.64 mm. With wear depth further up to 2.46 mm, the cup thickness (i.e. cup thinning on worn region) may be more predominant than increasing of contact area between the cup and the head. The wear on the inner surface of the cup is found to rule out the overall contact pressure and stress in the implant. Furthermore, individual and combined effects of both important parameters are analysed and discussed with respect to available clinical/laboratory studies.

The Utility of the Memorable Messages Framework as an Intermediary Evaluation Tool for Fruit and Vegetable Consumption in a Nutrition Education Program

Science.gov (United States)

Davis, LaShara A.; Morgan, Susan E.; Mobley, Amy R.

2016-01-01

Additional strategies to evaluate the impact of community nutrition education programs on low-income individuals are needed. The objective of this qualitative study was to examine the use of the Memorable Messages Framework as an intermediary nutrition education program evaluation tool to determine what fruit and vegetable messages were reported…

Early implant-associated osteomyelitis results in a peri-implanted bacterial reservoir

DEFF Research Database (Denmark)

Jensen, Louise Kruse; Koch, Janne; Aalbæk, Bent

2017-01-01

weight of Staphylococcus aureus or saline was inserted into the right tibial bone of 12 pigs. The animals were consecutively killed on day 2, 4 and 6 following implantation. Bone tissue around the implant was histologically evaluated. Identification of S. aureus was performed immunohistochemically...... on tissue section and with scanning electron microscopy and peptide nucleic acid in situ hybridization on implants. The distance of the peri-implanted pathological bone area (PIBA), measured perpendicular to the implant, was significantly larger in infected animals compared to controls (p = 0...

Influence of different implant materials on the primary stability of orthodontic mini-implants

OpenAIRE

Chin-Yun Pan; Szu-Ting Chou; Yu-Chuan Tseng; Yi-Hsin Yang; Chao-Yi Wu; Ting-Hsun Lan; Pao-Hsin Liu; Hong-Po Chang

2012-01-01

This study evaluates the influence of different implant materials on the primary stability of orthodontic mini-implants by measuring the resonance frequency. Twenty-five orthodontic mini-implants with a diameter of 2 mm were used. The first group contained stainless steel mini-implants with two different lengths (10 and 12 mm). The second group included titanium alloy mini-implants with two different lengths (10 and 12 mm) and stainless steel mini-implants 10 mm in length. The mini-implants w...

Ag-plasma modification enhances bone apposition around titanium dental implants: an animal study in Labrador dogs

Directory of Open Access Journals (Sweden)

Qiao SC

2015-01-01

Full Text Available Shichong Qiao,1,* Huiliang Cao,2,* Xu Zhao,1,* Hueiwen Lo,1 Longfei Zhuang,1 Yingxin Gu,1 Junyu Shi,1 Xuanyong Liu,2 Hongchang Lai1 1Department of Oral and Maxillofacial Implantology, Shanghai Key Laboratory of Stomatology, Shanghai Ninth People’s Hospital, School of Medicine, Shanghai Jiao Tong University, 2State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, People’s Republic of China *These authors contributed equally to this work Abstract: Dental implants with proper antibacterial ability as well as ideal osseointegration are being actively pursued. The antimicrobial ability of titanium implants can be significantly enhanced via modification with silver nanoparticles (Ag NPs. However, the high mobility of Ag NPs results in their potential cytotoxicity. The silver plasma immersion ion-implantation (Ag-PIII technique may remedy the defect. Accordingly, Ag-PIII technique was employed in this study in an attempt to reduce the mobility of Ag NPs and enhance osseointegration of sandblasted and acid-etched (SLA dental implants. Briefly, 48 dental implants, divided equally into one control and three test groups (further treated by Ag-PIII technique with three different implantation parameters, were inserted in the mandibles of six Labrador dogs. Scanning electron microscopy, X-ray photoelectron spectroscopy, and inductively coupled plasma optical emission spectrometry were used to investigate the surface topography, chemical states, and silver release of SLA- and Ag-PIII-treated titanium dental implants. The implant stability quotient examination, Microcomputed tomography evaluation, histological observations, and histomorphometric analysis were performed to assess the osseointegration effect in vivo. The results demonstrated that normal soft tissue healing around dental implants was observed in all the groups, whereas the implant stability

Influence of different implant materials on the primary stability of orthodontic mini-implants.

Science.gov (United States)

Pan, Chin-Yun; Chou, Szu-Ting; Tseng, Yu-Chuan; Yang, Yi-Hsin; Wu, Chao-Yi; Lan, Ting-Hsun; Liu, Pao-Hsin; Chang, Hong-Po

2012-12-01

This study evaluates the influence of different implant materials on the primary stability of orthodontic mini-implants by measuring the resonance frequency. Twenty-five orthodontic mini-implants with a diameter of 2 mm were used. The first group contained stainless steel mini-implants with two different lengths (10 and 12 mm). The second group included titanium alloy mini-implants with two different lengths (10 and 12 mm) and stainless steel mini-implants 10 mm in length. The mini-implants were inserted into artificial bones with a 2-mm-thick cortical layer and 40 or 20 lb/ft(3) trabecular bone density at insertion depths of 2, 4, and 6 mm. The resonance frequency of the mini-implants in the artificial bone was detected with the Implomates(®) device. Data were analyzed by two-way analysis of variance followed by the Tukey honestly significant difference test (α = 0.05). Greater insertion depth resulted in higher resonance frequency, whereas longer mini-implants showed lower resonance frequency values. However, resonance frequency was not influenced by the implant materials titanium alloy or stainless steel. Therefore, the primary stability of a mini-implant is influenced by insertion depth and not by implant material. Insertion depth is extremely important for primary implant stability and is critical for treatment success. Copyright © 2012. Published by Elsevier B.V.

Influence of different implant materials on the primary stability of orthodontic mini-implants

Directory of Open Access Journals (Sweden)

Chin-Yun Pan

2012-12-01

Full Text Available This study evaluates the influence of different implant materials on the primary stability of orthodontic mini-implants by measuring the resonance frequency. Twenty-five orthodontic mini-implants with a diameter of 2 mm were used. The first group contained stainless steel mini-implants with two different lengths (10 and 12 mm. The second group included titanium alloy mini-implants with two different lengths (10 and 12 mm and stainless steel mini-implants 10 mm in length. The mini-implants were inserted into artificial bones with a 2-mm-thick cortical layer and 40 or 20 lb/ft3 trabecular bone density at insertion depths of 2, 4, and 6 mm. The resonance frequency of the mini-implants in the artificial bone was detected with the Implomates® device. Data were analyzed by two-way analysis of variance followed by the Tukey honestly significant difference test (α = 0.05. Greater insertion depth resulted in higher resonance frequency, whereas longer mini-implants showed lower resonance frequency values. However, resonance frequency was not influenced by the implant materials titanium alloy or stainless steel. Therefore, the primary stability of a mini-implant is influenced by insertion depth and not by implant material. Insertion depth is extremely important for primary implant stability and is critical for treatment success.

Imaging of common breast implants and implant-related complications: A pictorial essay

OpenAIRE

Shah, Amisha T; Jankharia, Bijal B

2016-01-01

The number of women undergoing breast implant procedures is increasing exponentially. It is, therefore, imperative for a radiologist to be familiar with the normal and abnormal imaging appearances of common breast implants. Diagnostic imaging studies such as mammography, ultrasonography, and magnetic resonance imaging are used to evaluate implant integrity, detect abnormalities of the implant and its surrounding capsule, and detect breast conditions unrelated to implants. Magnetic resonance i...

Dental Implant Surgery

Science.gov (United States)

... here to find out more. Dental Implant Surgery Dental Implant Surgery Dental implant surgery is, of course, ... to find out more. Wisdom Teeth Management Wisdom Teeth Management An impacted wisdom tooth can damage neighboring ...

Conception of the Instrument Calibration Laboratory of Ionizing Radiation Measurement (LACIMRI) of CTMSP - Sao Paulo, SP

International Nuclear Information System (INIS)

Silva, Raimundo Dias da; Kibrit, Eduardo

2009-01-01

The present work describes the phases of implantation of calibration laboratory of ionizing radiation measurement instruments at the CTMSP, Sao Paulo, in a priory approved by CNEN, Brazil. That laboratory will allow and enhance the present metrological capacity for the attendance to the growing demand for calibration services of the instruments

[Clinical application of individualized three-dimensional printing implant template in multi-tooth dental implantation].

Science.gov (United States)

Wang, Lie; Chen, Zhi-Yuan; Liu, Rong; Zeng, Hao

2017-08-01

To study the value and satisfaction of three-dimensional printing implant template and conventional implant template in multi-tooth dental implantation. Thirty cases (83 teeth) with missing teeth needing to be implanted were randomly divided into conventional implant template group (CIT group, 15 cases, 42 teeth) and 3D printing implant template group (TDPIT group, 15 cases, 41 teeth). Patients in CIT group were operated by using conventional implant template, while patients in TDPIT group were operated by using three-dimensional printing implant template. The differences of implant neck and tip deviation, implant angle deviation and angle satisfaction between the two groups were compared. The difference of probing depth and bone resorption of implant were compared 1 year after operation between the two groups. The difference of success rate and satisfaction of dental implantation were compared 1 year after operation between the two groups. SPSS19.0 software package was used for statistical analysis. The deviation direction of the neck and the tip in disto-mesial, bucco-palatal, vertical direction and angle of implants in disto-mesial and bucco-palatal direction in TDPIT group were significantly lower than in CIT group (P0.05). The difference of the cumulative success rate in dental implantation at 3 months and 6 months between the two groups were not significant (P>0.05), but the cumulative success rate of TDPIT group was significantly higher than CIT group at 9 months and 1 year (90.48% vs 100%,P=0.043). The patients' satisfaction rate of dental implantation in TDPIT group was significantly higher than in CIT group (86.67% vs 53.33%, P=0.046). Using three-dimensional printing implant template can obtain better accuracy of implant, higher implant success rate and better patients' satisfaction than using conventional implant template. It is suitable for clinical application.

Osseointegration of zirconia implants: an SEM observation of the bone-implant interface.

Science.gov (United States)

Depprich, Rita; Zipprich, Holger; Ommerborn, Michelle; Mahn, Eduardo; Lammers, Lydia; Handschel, Jörg; Naujoks, Christian; Wiesmann, Hans-Peter; Kübler, Norbert R; Meyer, Ulrich

2008-11-06

The successful use of zirconia ceramics in orthopedic surgery led to a demand for dental zirconium-based implant systems. Because of its excellent biomechanical characteristics, biocompatibility, and bright tooth-like color, zirconia (zirconium dioxide, ZrO2) has the potential to become a substitute for titanium as dental implant material. The present study aimed at investigating the osseointegration of zirconia implants with modified ablative surface at an ultrastructural level. A total of 24 zirconia implants with modified ablative surfaces and 24 titanium implants all of similar shape and surface structure were inserted into the tibia of 12 Göttinger minipigs. Block biopsies were harvested 1 week, 4 weeks or 12 weeks (four animals each) after surgery. Scanning electron microscopy (SEM) analysis was performed at the bone implant interface. Remarkable bone attachment was already seen after 1 week which increased further to intimate bone contact after 4 weeks, observed on both zirconia and titanium implant surfaces. After 12 weeks, osseointegration without interposition of an interfacial layer was detected. At the ultrastructural level, there was no obvious difference between the osseointegration of zirconia implants with modified ablative surfaces and titanium implants with a similar surface topography. The results of this study indicate similar osseointegration of zirconia and titanium implants at the ultrastructural level.

Silicon quantum dots with counted antimony donor implants

Science.gov (United States)

Singh, Meenakshi; Pacheco, Jose; Perry, Daniel; Wendt, Joel; Manginell, Ronald; Dominguez, Jason; Pluym, Tammy; Luhman, Dwight; Bielejec, Edward; Lilly, Michael; Carroll, Malcolm

Antimony donor implants next to silicon quantum dots have been detected with integrated solid-state diode detectors with single ion precision. Devices with counted number of donors have been fabricated and low temperature transport measurements have been performed. Charge offsets, indicative of donor ionization and coupling to the quantum dot, have been detected in these devices. The number of offsets corresponds to 10-50% of the number of donors counted. We will report on tunneling time measurements and spin readout measurements on the donor offsets. This work was performed, in part, at the Center for Integrated Nanotechnologies, a U.S. DOE Office of Basic Energy Sciences user facility. The work was supported by Sandia National Laboratories Directed Research and Development Program. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a Lockheed-Martin Company, for the U. S. Department of Energy under Contract No. DE-AC04-94AL85000.

Influence of controlled immediate loading and implant design on peri-implant bone formation.

Science.gov (United States)

Vandamme, Katleen; Naert, Ignace; Geris, Liesbet; Vander Sloten, Jozef; Puers, Robert; Duyck, Joke

2007-02-01

Tissue formation at the implant interface is known to be sensitive to mechanical stimuli. The aim of the study was to compare the bone formation around immediately loaded versus unloaded implants in two different implant macro-designs. A repeated sampling bone chamber with a central implant was installed in the tibia of 10 rabbits. Highly controlled loading experiments were designed for a cylindrical (CL) and screw-shaped (SL) implant, while the unloaded screw-shaped (SU) implant served as a control. An F-statistic model with alpha=5% determined statistical significance. A significantly higher bone area fraction was observed for SL compared with SU (pimplant contact occurred was the highest for SL and significantly different from SU (pimplant contact was observed, a loading (SL versus SU: p=0.0049) as well as an implant geometry effect (SL versus CL: p=0.01) was found, in favour of the SL condition. Well-controlled immediate implant loading accelerates tissue mineralization at the interface. Adequate bone stimulation via mechanical coupling may account for the larger bone response around the screw-type implant compared with the cylindrical implant.

Influence of Implant Positions and Occlusal Forces on Peri-Implant Bone Stress in Mandibular Two-Implant Overdentures: A 3-Dimensional Finite Element Analysis.

Science.gov (United States)

Alvarez-Arenal, Angel; Gonzalez-Gonzalez, Ignacio; deLlanos-Lanchares, Hector; Brizuela-Velasco, Aritza; Dds, Elena Martin-Fernandez; Ellacuria-Echebarria, Joseba

2017-12-01

The aim of this study was to evaluate and compare the bone stress around implants in mandibular 2-implant overdentures depending on the implant location and different loading conditions. Four 3-dimensional finite element models simulating a mandibular 2-implant overdenture and a Locator attachment system were designed. The implants were located at the lateral incisor, canine, second premolar, and crossed-implant levels. A 150 N unilateral and bilateral vertical load of different location was applied, as was 40 N when combined with midline load. Data for von Mises stress were produced numerically, color coded, and compared between the models for peri-implant bone and loading conditions. With unilateral loading, in all 4 models much higher peri-implant bone stress values were recorded on the load side compared with the no-load side, while with bilateral occlusal loading, the stress distribution was similar on both sides. In all models, the posterior unilateral load showed the highest stress, which decreased as the load was applied more mesially. In general, the best biomechanical environment in the peri-implant bone was found in the model with implants at premolar level. In the crossed-implant model, the load side greatly altered the biomechanical environment. Overall, the overdenture with implants at second premolar level should be the chosen design, regardless of where the load is applied. The occlusal loading application site influences the bone stress around the implant. Bilateral occlusal loading distributes the peri-implant bone stress symmetrically, while unilateral loading increases it greatly on the load side, no matter where the implants are located.

Implantation of tomography qualities in Centro Regional de Ciencias Nucleares do Nordeste, Brazil

International Nuclear Information System (INIS)

Diniz, Osana F.; Silveira, Renata R.; Melo, Roberto T.; Oliveira, Marcia L.

2016-01-01

The quality guarantee of the service offered by a ionizing radiation metrology laboratory is deeply connected to the conformity to the radiation beams implanted to the determination and definition present in the international standards and adopted by the Brazilian National Commission of Nuclear Energy – CNEN. The objective of this work was the implementation of computerized tomography qualities, RQT 8, 9 e 10, in accordance with the IEC-61267 standard in the Metrology Laboratory of the Northeast Regional Center of Nuclear Sciences (CRCN-NE), PE, Brazil. (author)

Safety and efficacy of subretinal visual implants in humans: methodological aspects.

Science.gov (United States)

Stingl, Katarina; Bach, Michael; Bartz-Schmidt, Karl-Ulrich; Braun, Angelika; Bruckmann, Anna; Gekeler, Florian; Greppmaier, Udo; Hörtdörfer, Gernot; Kusnyerik, Akos; Peters, Tobias; Wilhelm, Barbara; Wilke, Robert; Zrenner, Eberhart

2013-01-01

Replacing the function of visual pathway neurons by electronic implants is a novel approach presently explored by various groups in basic research and clinical trials. The novelty raises unexplored methodological aspects of clinical trial design that may require adaptation and validation. We present procedures of efficacy and safety testing for subretinal visual implants in humans, as developed during our pilot trial 2005 to 2009 and multi-centre clinical trial since 2010. Planning such a trial requires appropriate inclusion and exclusion criteria. For subretinal electronic visual implants, patients with photoreceptor degeneration are the target patient group, whereas presence of additional diseases affecting clear optic media or the visual pathway must be excluded. Because sham surgery is not possible, a masked study design with implant power ON versus OFF is necessary. Prior to the efficacy testing by psychophysical tests, the implant's technical characteristics have to be controlled via electroretinography (ERG). Moreover the testing methods require adaptation to the particular technology. We recommend standardised tasks first to determine the light perception thresholds, light localisation and movement detection, followed by grating acuity and vision acuity test via Landolt C rings. A laboratory setup for assessing essential activities of daily living is presented. Subjective visual experiences with the implant in a natural environment, as well as questionnaires and psychological counselling are further important aspects. A clinical trial protocol for artificial vision in humans, which leads a patient from blindness to the state of very low vision is a challenge and cannot be defined completely prior to the study. Available tests of visual function may not be sufficiently suited for efficacy testing of artificial vision devices. A protocol based on experience with subretinal visual implants in 22 patients is presented that has been found adequate to monitor

CLINICAL CONSIDERATIONS OF DENTAL IMPLANT SYSTEM IN IMMEDIATE LOADING IMPLANT CASES

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Carolina Damayanti Marpaung

2015-06-01

Full Text Available Immediate loading of dental implant has been researched intensively in the development of Branemark’s early concept of 2 stages implant placement. This was embarked from both patients and practiitioner’s convenience towards a simpler protocol and shorter time frame. Many recent researchers later found that micromotions derived from occlusal loading for a certain degree, instead of resulting a fibrous tissue encapsulation, can enhance the osseointegration process. Dental Implant system enhancement towards maximizing the primary stability held a key factor in Branemark’s concept development. Surgical protocol and implant design was found to give a significant contribution to the prognosis of immediate-loading implants.

A fully implantable pacemaker for the mouse: from battery to wireless power.

Science.gov (United States)

Laughner, Jacob I; Marrus, Scott B; Zellmer, Erik R; Weinheimer, Carla J; MacEwan, Matthew R; Cui, Sophia X; Nerbonne, Jeanne M; Efimov, Igor R

2013-01-01

Animal models have become a popular platform for the investigation of the molecular and systemic mechanisms of pathological cardiovascular physiology. Chronic pacing studies with implantable pacemakers in large animals have led to useful models of heart failure and atrial fibrillation. Unfortunately, molecular and genetic studies in these large animal models are often prohibitively expensive or not available. Conversely, the mouse is an excellent species for studying molecular mechanisms of cardiovascular disease through genetic engineering. However, the large size of available pacemakers does not lend itself to chronic pacing in mice. Here, we present the design for a novel, fully implantable wireless-powered pacemaker for mice capable of long-term (>30 days) pacing. This design is compared to a traditional battery-powered pacemaker to demonstrate critical advantages achieved through wireless inductive power transfer and control. Battery-powered and wireless-powered pacemakers were fabricated from standard electronic components in our laboratory. Mice (n = 24) were implanted with endocardial, battery-powered devices (n = 14) and epicardial, wireless-powered devices (n = 10). Wireless-powered devices were associated with reduced implant mortality and more reliable device function compared to battery-powered devices. Eight of 14 (57.1%) mice implanted with battery-powered pacemakers died following device implantation compared to 1 of 10 (10%) mice implanted with wireless-powered pacemakers. Moreover, device function was achieved for 30 days with the wireless-powered device compared to 6 days with the battery-powered device. The wireless-powered pacemaker system presented herein will allow electrophysiology studies in numerous genetically engineered mouse models as well as rapid pacing-induced heart failure and atrial arrhythmia in mice.

A Fully Implantable Pacemaker for the Mouse: From Battery to Wireless Power

Science.gov (United States)

Zellmer, Erik R.; Weinheimer, Carla J.; MacEwan, Matthew R.; Cui, Sophia X.; Nerbonne, Jeanne M.; Efimov, Igor R.

2013-01-01

Animal models have become a popular platform for the investigation of the molecular and systemic mechanisms of pathological cardiovascular physiology. Chronic pacing studies with implantable pacemakers in large animals have led to useful models of heart failure and atrial fibrillation. Unfortunately, molecular and genetic studies in these large animal models are often prohibitively expensive or not available. Conversely, the mouse is an excellent species for studying molecular mechanisms of cardiovascular disease through genetic engineering. However, the large size of available pacemakers does not lend itself to chronic pacing in mice. Here, we present the design for a novel, fully implantable wireless-powered pacemaker for mice capable of long-term (>30 days) pacing. This design is compared to a traditional battery-powered pacemaker to demonstrate critical advantages achieved through wireless inductive power transfer and control. Battery-powered and wireless-powered pacemakers were fabricated from standard electronic components in our laboratory. Mice (n = 24) were implanted with endocardial, battery-powered devices (n = 14) and epicardial, wireless-powered devices (n = 10). Wireless-powered devices were associated with reduced implant mortality and more reliable device function compared to battery-powered devices. Eight of 14 (57.1%) mice implanted with battery-powered pacemakers died following device implantation compared to 1 of 10 (10%) mice implanted with wireless-powered pacemakers. Moreover, device function was achieved for 30 days with the wireless-powered device compared to 6 days with the battery-powered device. The wireless-powered pacemaker system presented herein will allow electrophysiology studies in numerous genetically engineered mouse models as well as rapid pacing-induced heart failure and atrial arrhythmia in mice. PMID:24194832

A fully implantable pacemaker for the mouse: from battery to wireless power.

Directory of Open Access Journals (Sweden)

Jacob I Laughner

Full Text Available Animal models have become a popular platform for the investigation of the molecular and systemic mechanisms of pathological cardiovascular physiology. Chronic pacing studies with implantable pacemakers in large animals have led to useful models of heart failure and atrial fibrillation. Unfortunately, molecular and genetic studies in these large animal models are often prohibitively expensive or not available. Conversely, the mouse is an excellent species for studying molecular mechanisms of cardiovascular disease through genetic engineering. However, the large size of available pacemakers does not lend itself to chronic pacing in mice. Here, we present the design for a novel, fully implantable wireless-powered pacemaker for mice capable of long-term (>30 days pacing. This design is compared to a traditional battery-powered pacemaker to demonstrate critical advantages achieved through wireless inductive power transfer and control. Battery-powered and wireless-powered pacemakers were fabricated from standard electronic components in our laboratory. Mice (n = 24 were implanted with endocardial, battery-powered devices (n = 14 and epicardial, wireless-powered devices (n = 10. Wireless-powered devices were associated with reduced implant mortality and more reliable device function compared to battery-powered devices. Eight of 14 (57.1% mice implanted with battery-powered pacemakers died following device implantation compared to 1 of 10 (10% mice implanted with wireless-powered pacemakers. Moreover, device function was achieved for 30 days with the wireless-powered device compared to 6 days with the battery-powered device. The wireless-powered pacemaker system presented herein will allow electrophysiology studies in numerous genetically engineered mouse models as well as rapid pacing-induced heart failure and atrial arrhythmia in mice.

Psychological intervention following implantation of an implantable defibrillator

DEFF Research Database (Denmark)

Pedersen, Susanne S.; van den Broek, Krista C; Sears, Samuel F

2007-01-01

The medical benefits of the implantable cardioverter defibrillator (ICD) are unequivocal, but a subgroup of patients experiences emotional difficulties following implantation. For this subgroup, some form of psychological intervention may be warranted. This review provides an overview of current ...

Prevalence of Peri-Implant Mucositis and Peri-Implantitis in Patients Treated with a Combination of Axial and Tilted Implants Supporting a Complete Fixed Denture

Directory of Open Access Journals (Sweden)

Nicolò Cavalli

2015-01-01

Full Text Available Objectives. The aim of this retrospective study was to assess the incidence and prevalence of peri-implant mucositis and peri-implantitis in patients with a fixed full-arch prosthesis supported by two axial and two tilted implants. Materials and Methods. Sixty-nine patients were included in the study. Each patient received a fixed full-arch prosthesis supported by two mesial axial and two distal tilted implants to rehabilitate the upper arch, the lower arch, or both. Three hundred thirty-six implants for 84 restorations were delivered. Patients were scheduled for follow-up visits every 6 months in the first 2 years and yearly after. At each follow-up visit peri-implant mucositis and peri-implantitis were diagnosed if present. Results. The overall follow-up range was from 12 to 130 months (mean 63,2 months. Three patients presented peri-implantitis. The prevalence of peri-implant mucositis ranged between 0 and 7,14% of patients (5,06% of implants while the prevalence of peri-implantitis varied from 0 to 4,55% of patients (3,81% of implants. Conclusions. The prevalence and incidence of peri-implant mucositis and peri-implantitis are lower than most of the studies in literature. Therefore this kind of rehabilitation could be considered a feasible option, on the condition of adopting a systematic hygienic protocol.

A new system of implant abutment connection: how to improve a two piece implant system sealing.

Science.gov (United States)

Grecchi, F; DI Girolamo, M; Cura, F; Candotto, V; Carinci, F

2017-01-01

Implant dentistry has become one of the most successful dentistry techniques for replacing missing teeth. The success rate of implant dentistry is above 80%. However, peri-implantitis is a later complication of implant dentistry that if untreated, can lead to implant loss. One of the hypotized causes of peri-implantis is the bacterial leakage at the level of implant-abutment connection. Bacterial leakage is favored to the presence of a micro gap at the implant-abutment interface, allowing microorganisms to penetrate and colonize the inner part of the implant leading to biofilm accumulation and consequently to peri-implantitis development. To identify the capability of the implant to protect the internal space from the external environment, the passage of genetically modified Escherichia coli across implant-abutment interface was evaluated. Implants were immerged in a bacterial culture for twenty-four hours and then bacteria amount was measured inside implant-abutment interface with Real-time PCR. Bacteria were detected inside all studied implants, with a median percentage of 9%. The reported results are better to those of previous studies carried out on different implant systems. Until now, none implant-abutment system has been proven to seal the gap between implant and abutment.

Poly Implants Prosthèse Breast Implants: A Case Series and Review of the Literature.

Science.gov (United States)

Klein, Doron; Hadad, Eran; Wiser, Itay; Wolf, Omer; Itzhaki Shapira, Ortal; Fucks, Shir; Heller, Lior

2018-01-01

Silicone breast implants from the French manufacturer Poly Implants Prosthèse (PIP) were recalled from the European market after the French regulator has revealed the implants contain non-medical-grade silicone filler. In December 2011, following a large increase in reported rupture rate and a possible cancer risk, the French Ministry of Health recommended consideration of the PIP explantation, regardless of their condition. In 2012, the Israel Ministry of Health recommended to replace the implants only upon suspected implant rupture. The aims of this study were to characterize breast-augmented Israeli patients with PIP implants, compare their outcomes with those of breast-augmented patients with different implant types, and review the current PIP literature. Breast-augmented patients who underwent an elective breast implant exchange in Israel between January 2011 and January 2017 were included in the study. Data were collected from electronic and physical medical files. There were 73 breast-augmented female patients with 146 PIP breast implants included in this study. Average implant age was 6.7 ± 2.79 years. Mean implant size was 342.8 ± 52.9 mL. Fourteen women (19 implants [16%]) had a high-grade capsular contracture (Baker grade 3-4). During exchange, 28 implants were found to be ruptured (19.2%). Less than 10 years following breast augmentation, PIP implants demonstrated higher rupture rate compared with other implants. Our data are comparable to overall available rupture rate. Among patients with definitive rupture diagnosis, an elective implant removal should be recommended. In cases of undamaged implants, plastic surgeons should also seriously consider PIP implant explantation. When the patient does not desire to remove the implant, an annual physical examination and breast ultrasound are recommended, beginning a year after augmentation.

Ion implantation into diamond

International Nuclear Information System (INIS)

Sato, Susumu

1994-01-01

The graphitization and the change to amorphous state of diamond surface layer by ion implantation and its characteristics are reported. In the diamond surface, into which more than 10 16 ions/cm 2 was implanted, the diamond crystals are broken, and the structure changes to other carbon structure such as amorphous state or graphite. Accompanying this change of structure, the electric conductivity of the implanted layer shows two discontinuous values due to high resistance and low resistance. This control of structure can be done by the temperature of the base during the ion implantation into diamond. Also it is referred to that by the base temperature during implantation, the mutual change of the structure between amorphous state and graphite can be controlled. The change of the electric resistance and the optical characteristics by the ion implantation into diamond surface, the structural analysis by Raman spectroscopy, and the control of the structure of the implanted layer by the base temperature during implantation are reported. (K.I.)

Sacroiliac joint stability: Finite element analysis of implant number, orientation, and superior implant length.

Science.gov (United States)

Lindsey, Derek P; Kiapour, Ali; Yerby, Scott A; Goel, Vijay K

2018-03-18

To analyze how various implants placement variables affect sacroiliac (SI) joint range of motion. An experimentally validated finite element model of the lumbar spine and pelvis was used to simulate a fusion of the SI joint using various placement configurations of triangular implants (iFuse Implant System ® ). Placement configurations were varied by changing implant orientation, superior implant length, and number of implants. The range of motion of the SI joint was calculated using a constant moment of 10 N-m with a follower load of 400 N. The changes in motion were compared between the treatment groups to assess how the different variables affected the overall motion of the SI joint. Transarticular placement of 3 implants with superior implants that end in the middle of the sacrum resulted in the greatest reduction in range of motion (flexion/extension = 73%, lateral bending = 42%, axial rotation = 72%). The range of motions of the SI joints were reduced with use of transarticular orientation (9%-18%) when compared with an inline orientation. The use of a superior implant that ended mid-sacrum resulted in median reductions of (8%-14%) when compared with a superior implant that ended in the middle of the ala. Reducing the number of implants, resulted in increased SI joint range of motions for the 1 and 2 implant models of 29%-133% and 2%-39%, respectively, when compared with the 3 implant model. Using a validated finite element model we demonstrated that placement of 3 implants across the SI joint using a transarticular orientation with superior implant reaching the sacral midline resulted in the most stable construct. Additional clinical studies may be required to confirm these results.

Evaluation of rotation and visual outcomes after implantation of monofocal and multifocal toric intraocular lenses.

Science.gov (United States)

Garzón, Nuria; Poyales, Francisco; de Zárate, Begoña Ortíz; Ruiz-García, Jose Luis; Quiroga, Juan Antonio

2015-02-01

To evaluate rotational stability and its influence on postoperative visual acuity of different monofocal and multifocal toric intraocular lenses (IOLs). A prospective interventional study was designed. Ninety-one patients with a mean age of 71.65 ± 11.82 years were implanted with toric IOLs after phacoemulsification. Three monofocal toric IOLs (the Lentis LT [Oculentis, Berlin, Germany], enVista [Bausch & Lomb, Rochester, NY], and AcrySof IQ [Alcon Laboratories, Inc., Fort Worth, TX]) and one multifocal toric IOL (AcrySof IQ ReSTOR; Alcon Laboratories, Inc.) were implanted. Preoperative and postoperative images were taken to calculate the misalignment due to the marking method. To evaluate rotation in the different follow-up visits, another photograph was taken 1 hour and 1, 7 and 30 days postoperatively. Refraction, uncorrected distance visual acuity (UDVA), and corrected distance visual acuity were measured 30 days postoperatively. Postoperative UDVA was 0.1 logMAR or better in 64.6% of eyes implanted with monofocal IOLs and 46.4% of eyes implanted with multifocal IOLs. The enVista toric IOL showed the best UDVA compared to the other monofocal IOLs, with 81% of eyes with 0.1 logMAR or better. The mean misalignment in the total group studied was 0.07° ± 0.60°; 69.6% of monofocal IOLs and 67.9% of multifocal IOLs showed less than 5° of rotation. A correlation was found between postoperative UDVA and rotation in the monofocal and multifocal IOLs implanted (r = 0.439 [P < .011] and = 0.787 [P = .001], respectively). At 1 month postoperatively, UDVA was slightly more affected by IOL rotation in multifocal than monofocal toric IOLs. The marking method was also effective. Copyright 2015, SLACK Incorporated.

Magnetic resonance imaging in cadaver dogs with metallic vertebral implants at 3 Tesla: evaluation of the WARP-turbo spin echo sequence.

Science.gov (United States)

Griffin, John F; Archambault, Nicholas S; Mankin, Joseph M; Wall, Corey R; Thompson, James A; Padua, Abraham; Purdy, David; Kerwin, Sharon C

2013-11-15

Laboratory investigation, ex vivo. Postoperative complications are common after spinal implantation procedures, and magnetic resonance imaging (MRI) would be the ideal modality to image these patients. Unfortunately, the implants cause artifacts that can render MRI nondiagnostic. The WARP-turbo spin echo (TSE) sequence has been developed to mitigate artifacts caused by metal. The objective of this investigation was to evaluate the performance of the WARP-TSE sequence in canine cadaver specimens after implantation with metallic vertebral implants. Magnetic field strength, implant type, and MRI acquisition technique all play a role in the severity of susceptibility artifacts. The WARP-TSE sequence uses increased bandwidth, view angle tilting, and SEMAC (slice-encoding metal artifact correction) to correct for susceptibility artifact. The WARP-TSE technique has outperformed conventional techniques in patients, after total hip arthroplasty. However, published reports of its application in subjects with vertebral column implants are lacking. Ex vivo anterior stabilization of the atlantoaxial joint was performed on 6 adult small breed (implantation with stainless steel implants. N/A.

Hierarchical micro/nanostructured titanium with balanced actions to bacterial and mammalian cells for dental implants

Directory of Open Access Journals (Sweden)

Zhu Y

2015-10-01

Full Text Available Yu Zhu,1,* Huiliang Cao,2,* Shichong Qiao,1,* Manle Wang,2,3 Yingxin Gu,1 Huiwen Luo,1 Fanhao Meng,2 Xuanyong Liu,2 Hongchang Lai1 1Department of Oral and Maxillofacial Implantology, Shanghai Key Laboratory of Stomatology, Shanghai Ninth People’s Hospital, School of Medicine, Shanghai Jiao Tong University, 2State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 3School of Materials Engineering, Shanghai University of Engineering Science, Shanghai, People’s Republic of China *These authors contributed equally to this work Abstract: A versatile strategy to endow dental implants with long-term antibacterial ability without compromising the cytocompatibility is highly desirable to combat implant-related infection. Silver nanoparticles (Ag NPs have been utilized as a highly effective and broad-spectrum antibacterial agent for surface modification of biomedical devices. However, the high mobility and subsequent hazardous effects of the particles on mammalian cells may limit its practical applications. Thus, Ag NPs were immobilized on the surface of sand-blasted, large grit, and acid-etched (SLA titanium by manipulating the atomic-scale heating effect of silver plasma immersion ion implantation. The silver plasma immersion ion implantation-treated SLA surface gave rise to both good antibacterial activity and excellent compatibility with mammalian cells. The antibacterial activity rendered by the immobilized Ag NPs was assessed using Fusobacterium nucleatum and Staphylococcus aureus, commonly suspected pathogens for peri-implant disease. The immobilized Ag NPs offered a good defense against multiple cycles of bacteria attack in both F. nucleatum and S. aureus, and the mechanism was independent of silver release. F. nucleatum showed a higher susceptibility to Ag NPs than S. aureus, which might be explained by the presence of different wall structures. Moreover, the

Impact of cone-beam computed tomography on implant planning and on prediction of implant size

Energy Technology Data Exchange (ETDEWEB)

Pedroso, Ludmila Assuncao de Mello; Silva, Maria Alves Garcia Santos, E-mail: ludmilapedroso@hotmail.com [Universidade Federal de Goias (UFG), Goiania, GO (Brazil). Fac. de Odontologia; Garcia, Robson Rodrigues [Universidade Federal de Goias (UFG), Goiania, GO (Brazil). Fac. de Odontologia. Dept. de Medicina Oral; Leles, Jose Luiz Rodrigues [Universidade Paulista (UNIP), Goiania, GO (Brazil). Fac. de Odontologia. Dept. de Cirurgia; Leles, Claudio Rodrigues [Universidade Federal de Goias (UFG), Goiania, GO (Brazil). Fac. de Odontologia. Dept. de Prevencao e Reabilitacao Oral

2013-11-15

The aim was to investigate the impact of cone-beam computed tomography (CBCT) on implant planning and on prediction of final implant size. Consecutive patients referred for implant treatment were submitted to clinical examination, panoramic (PAN) radiography and a CBCT exam. Initial planning of implant length and width was assessed based on clinical and PAN exams, and final planning, on CBCT exam to complement diagnosis. The actual dimensions of the implants placed during surgery were compared with those obtained during initial and final planning, using the McNemmar test (p < 0.05). The final sample comprised 95 implants in 27 patients, distributed over the maxilla and mandible. Agreement in implant length was 50.5% between initial and final planning, and correct prediction of the actual implant length was 40.0% and 69.5%, using PAN and CBCT exams, respectively. Agreement in implant width assessment ranged from 69.5% to 73.7%. A paired comparison of the frequency of changes between initial or final planning and implant placement (McNemmar test) showed greater frequency of changes in initial planning for implant length (p < 0.001), but not for implant width (p = 0.850). The frequency of changes was not influenced by implant location at any stage of implant planning (chi-square test, p > 0.05). It was concluded that CBCT improves the ability of predicting the actual implant length and reduces inaccuracy in surgical dental implant planning. (author)

In vitro assessment of tissue heating near metallic medical implants by exposure to pulsed radio frequency diathermy

Energy Technology Data Exchange (ETDEWEB)

Ruggera, P S; Witters, D M; Maltzahn, G von; Bassen, H I [Center for Devices and Radiological Health, Food and Drug Administration, HFZ-133, 9200 Corporate Blvd., Rockville, MD 20850 (United States)

2003-09-07

A patient with bilateral implanted neurostimulators suffered significant brain tissue damage, and subsequently died, following diathermy treatment to hasten recovery from teeth extraction. Subsequent MRI examinations showed acute deterioration of the tissue near the deep brain stimulator (DBS) lead's electrodes which was attributed to excessive tissue heating induced by the diathermy treatment. Though not published in the open literature, a second incident was reported for a patient with implanted neurostimulators for the treatment of Parkinson's disease. During a diathermy treatment for severe kyphosis, the patient had a sudden change in mental status and neurological deficits. The diathermy was implicated in causing damage to the patient's brain tissue. To investigate if diathermy induced excessive heating was possible with other types of implantable lead systems, or metallic implants in general, we conducted a series of in vitro laboratory tests. We obtained a diathermy unit and also assembled a controllable laboratory exposure system. Specific absorption rate (SAR) measurements were performed using fibre optic thermometry in proximity to the implants to determine the rate of temperature rise using typical diathermy treatment power levels. Comparisons were made of the SAR measurements for a spinal cord stimulator (SCS) lead, a pacemaker lead and three types of bone prosthesis (screws, rods and a plate). Findings indicate that temperature changes of 2.54 and 4.88 deg. C s{sup -1} with corresponding SAR values of 9129 and 17 563 W kg{sup -1} near the SCS and pacemaker electrodes are significantly higher than those found in the proximity of the other metallic implants which ranged from 0.04 to 0.69 deg C s{sup -1} (129 to 2471 W kg{sup -1}). Since the DBS leads that were implanted in the reported human incidents have one-half the electrode surface area of the tested SCS lead, these results imply that tissue heating at rates at least equal to or up to

In vitro assessment of tissue heating near metallic medical implants by exposure to pulsed radio frequency diathermy

International Nuclear Information System (INIS)

Ruggera, P S; Witters, D M; Maltzahn, G von; Bassen, H I

2003-01-01

A patient with bilateral implanted neurostimulators suffered significant brain tissue damage, and subsequently died, following diathermy treatment to hasten recovery from teeth extraction. Subsequent MRI examinations showed acute deterioration of the tissue near the deep brain stimulator (DBS) lead's electrodes which was attributed to excessive tissue heating induced by the diathermy treatment. Though not published in the open literature, a second incident was reported for a patient with implanted neurostimulators for the treatment of Parkinson's disease. During a diathermy treatment for severe kyphosis, the patient had a sudden change in mental status and neurological deficits. The diathermy was implicated in causing damage to the patient's brain tissue. To investigate if diathermy induced excessive heating was possible with other types of implantable lead systems, or metallic implants in general, we conducted a series of in vitro laboratory tests. We obtained a diathermy unit and also assembled a controllable laboratory exposure system. Specific absorption rate (SAR) measurements were performed using fibre optic thermometry in proximity to the implants to determine the rate of temperature rise using typical diathermy treatment power levels. Comparisons were made of the SAR measurements for a spinal cord stimulator (SCS) lead, a pacemaker lead and three types of bone prosthesis (screws, rods and a plate). Findings indicate that temperature changes of 2.54 and 4.88 deg. C s -1 with corresponding SAR values of 9129 and 17 563 W kg -1 near the SCS and pacemaker electrodes are significantly higher than those found in the proximity of the other metallic implants which ranged from 0.04 to 0.69 deg C s -1 (129 to 2471 W kg -1 ). Since the DBS leads that were implanted in the reported human incidents have one-half the electrode surface area of the tested SCS lead, these results imply that tissue heating at rates at least equal to or up to twice as much as those reported

Metals for bone implants. Part 1. Powder metallurgy and implant rendering.

Science.gov (United States)

Andani, Mohsen Taheri; Shayesteh Moghaddam, Narges; Haberland, Christoph; Dean, David; Miller, Michael J; Elahinia, Mohammad

2014-10-01

New metal alloys and metal fabrication strategies are likely to benefit future skeletal implant strategies. These metals and fabrication strategies were looked at from the point of view of standard-of-care implants for the mandible. These implants are used as part of the treatment for segmental resection due to oropharyngeal cancer, injury or correction of deformity due to pathology or congenital defect. The focus of this two-part review is the issues associated with the failure of existing mandibular implants that are due to mismatched material properties. Potential directions for future research are also studied. To mitigate these issues, the use of low-stiffness metallic alloys has been highlighted. To this end, the development, processing and biocompatibility of superelastic NiTi as well as resorbable magnesium-based alloys are discussed. Additionally, engineered porosity is reviewed as it can be an effective way of matching the stiffness of an implant with the surrounding tissue. These porosities and the overall geometry of the implant can be optimized for strain transduction and with a tailored stiffness profile. Rendering patient-specific, site-specific, morphology-specific and function-specific implants can now be achieved using these and other metals with bone-like material properties by additive manufacturing. The biocompatibility of implants prepared from superelastic and resorbable alloys is also reviewed. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Novel implant design improves implant survival in multirooted extraction sites: a preclinical pilot study.

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Sivan-Gildor, Adi; Machtei, Eli E; Gabay, Eran; Frankenthal, Shai; Levin, Liran; Suzuki, Marcelo; Coelho, Paulo G; Zigdon-Giladi, Hadar

2014-10-01

The primary aim is to evaluate clinical, radiographic, and histologic parameters of novel implants with "three roots" design that were inserted into fresh multirooted extraction sockets. A secondary aim is to compare this new implant to standard root-form dental implants. Immediate implantation of novel or standard design 6 × 6-mm implants was performed bilaterally into multirooted sockets in mandibles of mini-pigs. Twelve weeks later, clinical, radiographic, stability, histomorphometric, and microcomputed tomography (micro-CT) analyses were performed. Survival rates were significantly higher in the test implants compared with control (92.8% versus 33.3%, respectively; P micro-CT analyses demonstrated bone fill in the inner part of the test implants. Moreover, bone-to-implant contact was higher in the test implants (55.50% ± 3.68% versus 42.47% ± 9.89%). Contrary to the clinical, radiographic, and histomorphometric results, resonance frequency analysis measurements were greater in the control group (77.74 ± 3.21 implant stability quotient [ISQ]) compared with the test group (31.09 ± 0.28 ISQ), P = 0.008. The novel design implants resulted in significantly greater survival rate in multirooted extraction sites. Further studies will be required to validate these findings.

Group D. Initiator paper. Implants--peri-implant (hard and soft tissue) interactions in health and disease: the impact of explosion of implant manufacturers.

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Ivanovski, Saso

2015-01-01

1. The best-documented implants have a threaded solid screw-type design and are manufactured from commercially pure (grade IV) titanium. There is good evidence to support implants ≥ 6 mm in length, and ≥ 3 mm in diameter. 2. Integrity of the seal between the abutment and the implant is important for several reasons, including minimization of mechanical and biological complications and maintaining marginal bone levels. Although the ideal design features of the implant-abutment connection have not been determined, an internal connection, micro-grooves at the implant collar, and horizontal offset of the implant-abutment junction (platform switch) appear to impart favorable properties. 3. Implants with moderately rough implant surfaces provide advantages over machined surfaces in terms of the speed and extent of osseointegration. While the favorable performances of both minimally and moderately rough surfaces are supported by long-term data, moderately rough surfaces provide superior outcomes in compromised sites, such as the posterior maxilla. 4. Although plaque is critical in the progression of peri-implantitis, the disease has a multi-factorial aetiology, and may be influenced by poor integrity of the abutment/implant connection. Iatrogenic factors, such as the introduction of a foreign body. (e.g., cement) below the mucosal margin, can be important contributors. 5. Clinicians should exercise caution when using a particular implant system, ensuring that the implant design is appropriate and supported by scientific evidence. Central to this is access to and participation in quality education on the impact that implant characteristics can have on clinical outcomes. Caution should be exercised in utilizing non-genuine restorative componentry that may lead to a poor implant-abutment fit and subsequent technical and biological complications.

Structure of ion-implanted ceramics

International Nuclear Information System (INIS)

Naramoto, Hiroshi

1983-01-01

The variation of structure of LiF, MgO, Al 2 O 3 and TiO 2 accompanying annealing after ion implantation is explained. The analysis of structure is usually made by the perturbed gamma ray angular correlation, the internal electron Moessbauer method, or the ion scattering method. The results of analyses are discussed for alkali ion implantation, Fe-ion implantation, In-ion implantation, Au-ion implantation, Pt-ion implantation, Pb-ion implantation and transition metal ion implantation. The coupling of the implanted elements with lattice defects and matrix elements, and the compatibility between deposited elements and matrix crystal lattice were studied. The variation of physical properties due to ion implantation such as phase transition, volume change, the control of single crystal region, and the variation of hardness near surface were investigated, and the examples are presented. (Kato, T.)

Ion implantation technology

CERN Document Server

Downey, DF; Jones, KS; Ryding, G

1993-01-01

Ion implantation technology has made a major contribution to the dramatic advances in integrated circuit technology since the early 1970's. The ever-present need for accurate models in ion implanted species will become absolutely vital in the future due to shrinking feature sizes. Successful wide application of ion implantation, as well as exploitation of newly identified opportunities, will require the development of comprehensive implant models. The 141 papers (including 24 invited papers) in this volume address the most recent developments in this field. New structures and possible approach

Individual titanium zygomatic implant

Science.gov (United States)

Nekhoroshev, M. V.; Ryabov, K. N.; Avdeev, E. V.

2018-03-01

Custom individual implants for the reconstruction of craniofacial defects have gained importance due to better qualitative characteristics over their generic counterparts – plates, which should be bent according to patient needs. The Additive Manufacturing of individual implants allows reducing cost and improving quality of implants. In this paper, the authors describe design of zygomatic implant models based on computed tomography (CT) data. The fabrication of the implants will be carried out with 3D printing by selective laser melting machine SLM 280HL.

A 5-year randomized trial to compare 1 or 2 implants for implant overdentures.

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Bryant, S R; Walton, J N; MacEntee, M I

2015-01-01

The hypothesis of this 5-y randomized clinical trial was that there would be no significant difference in the satisfaction of edentulous participants with removable complete overdentures attached to 1 or 2 mandibular implants. Secondary aims were to test changes in satisfaction between and within the groups from baseline to 5 y and differences between the groups in implant survival and prosthodontic maintenance over 5 y. Each of the 86 participants (mean age, 67 y) was randomly allocated to receive either 1 implant in the midline (group 1) or 2 implants in the canine areas (group 2) attached to a mandibular overdenture opposing a maxillary complete denture. Satisfaction was self-assessed by participants on a visual analog scale at baseline prior to implants, as well as at 2 mo and 1, 3, and 5 y with implant overdentures, whereas implant survival and prosthodontic maintenance were assessed by clinical examination. After 5 y, 29 participants in group 1 and 33 in group 2 were available, with most dropouts due to death. Satisfaction with the implant denture after 5 y was significantly (P overdentures retained by 1 implant or 2 implants. Additional research is required to confirm long-term treatment effectiveness of single-implant dentures and the implications of prosthetic maintenance with implant overdentures (ClinicalTrials.gov: NCT02117856). © International & American Associations for Dental Research 2014.

Recent advances in dental implants.

Science.gov (United States)

Hong, Do Gia Khang; Oh, Ji-Hyeon

2017-12-01

Dental implants are a common treatment for the loss of teeth. This paper summarizes current knowledge on implant surfaces, immediate loading versus conventional loading, short implants, sinus lifting, and custom implants using three-dimensional printing. Most of the implant surface modifications showed good osseointegration results. Regarding biomolecular coatings, which have been recently developed and studied, good results were observed in animal experiments. Immediate loading had similar clinical outcomes compared to conventional loading and can be used as a successful treatment because it has the advantage of reducing treatment times and providing early function and aesthetics. Short implants showed similar clinical outcomes compared to standard implants. A variety of sinus augmentation techniques, grafting materials, and alternative techniques, such as tilted implants, zygomatic implants, and short implants, can be used. With the development of new technologies in three-dimension and computer-aided design/computer-aided manufacturing (CAD/CAM) customized implants can be used as an alternative to conventional implant designs. However, there are limitations due to the lack of long-term studies or clinical studies. A long-term clinical trial and a more predictive study are needed.

Comparison of Reconstructive Outcomes in Breast Cancer Patients With Preexisting Subpectoral Implants: Implant-Sparing Mastectomy With Delayed Implant Exchange Versus Immediate Tissue Expander Reconstruction.

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Parabkaharan, Sangeetha; Melody, Megan; Trotta, Rose; Lleshi, Amina; Sun, Weihong; Smith, Paul D; Khakpour, Nazanin; Dayicioglu, Deniz

2016-06-01

Women who have undergone prior augmentation mammoplasty represent a unique subset of breast cancer patients with several options available for breast reconstruction. We performed a single institution review of surgical outcomes of breast reconstruction performed in patients with breast cancer with prior history of subpectoral breast augmentation. Institutional review board-approved retrospective review was conducted among patients with previously mentioned criteria treated at our institution between 2000 and 2014. Reconstructions were grouped into 2 categories as follows: (1) removal of preexisting subpectoral implant during mastectomy with immediate tissue expander placement and (2) implant-sparing mastectomy followed by delayed exchange to a larger implant. We reviewed demographics, tumor features, and reconstruction outcomes of these groups. Fifty-three patients had preexisting subpectoral implants. Of the 63 breast reconstructions performed, 18 (28.6%) had immediate tissue expander placed and 45 (71.4%) had implant-sparing mastectomy followed by delayed implant exchange. The groups were comparable based on age, body mass index, cancer type, tumor grade, TNM stage at presentation, and hormonal receptor status. No significant difference was noted between tumor margins or subsequent recurrence, mastectomy specimen weight, removed implant volume, volume of implant placed during reconstruction, or time from mastectomy to final implant placement. Rates of complications were significantly higher in the tissue expander group compared to the implant-sparing mastectomy group 7 (38.9%) versus 4 (8.9%) (P = 0.005). Implant-sparing mastectomy with delayed implant exchange in patients with preexisting subpectoral implants is safe and has fewer complications compared to tissue expander placement. There was no difference noted in the final volume of implant placed, time interval for final implant placement, or tumor margins.

Effect of implant design and bioactive glass coating on biomechanical properties of fiber-reinforced composite implants.

Science.gov (United States)

Ballo, Ahmed M; Akca, Eralp; Ozen, Tuncer; Moritz, Niko; Lassila, Lippo; Vallittu, Pekka; Närhi, Timo

2014-08-01

This study aimed to evaluate the influence of implant design and bioactive glass (BAG) coating on the response of bone to fiber-reinforced composite (FRC) implants. Three different FRC implant types were manufactured for the study: non-threaded implants with a BAG coating; threaded implants with a BAG coating; and threaded implants with a grit-blasted surface. Thirty-six implants (six implants for each group per time point) were installed in the tibiae of six pigs. After an implantation period of 4 and 12 wk, the implants were retrieved and prepared for micro-computed tomography (micro-CT), push-out testing, and scanning electron microscopy analysis. Micro-CT demonstrated that the screw-threads and implant structure remained undamaged during the installation. The threaded FRC/BAG implants had the highest bone volume after 12 wk of implantation. The push-out strengths of the threaded FRC/BAG implants after 4 and 12 wk (463°N and 676°N, respectively) were significantly higher than those of the threaded FRC implants (416°N and 549°N, respectively) and the nonthreaded FRC/BAG implants (219°N and 430°N, respectively). Statistically significant correlation was found between bone volume and push-out strength values. This study showed that osseointegrated FRC implants can withstand the static loading up to failure without fracture, and that the addition of BAG significantly improves the push-out strength of FRC implants. © 2014 Eur J Oral Sci.

Mecanobiología de la interfase hueso-implante dental Mechanobiology of bone-dental implant interphase

Directory of Open Access Journals (Sweden)

Juan Carlos Vanegas Acosta

2010-03-01

Full Text Available La osteointegración es la conexión estructural y funcional entre el hueso y un implante. Cuando un implante se inserta en el hueso, se crea la denominada interfase hueso-implante, una zona de unión entre la superficie del biomaterial del implante y el hueso circundante. La cicatrización de esta interfase depende de las condiciones biológicas del hueso, las características de diseño del implante y la distribución de cargas entre hueso e implante. En este artículo se hace una revisión del proceso de cicatrización de la interfase hueso-implante para el caso de un implante dental. El objetivo es describir la secuencia de eventos biológicos iniciados con la lesión causada por la inserción del implante y que concluyen con la formación de nuevo hueso en la interfase. Esta descripción incluye una novedosa clasificación de los fenómenos mecánicos que intervienen durante el proceso de cicatrización de los tejidos lesionados. Esta descripción mecanobiológica de la interfase hueso-implante dental se utiliza para determinar las características más relevantes a tener en cuenta en la formulación de un modelo matemático de la osteointegración de implantes dentales.The osteointegration is the structural and functional connection between bone and implant. When an implant is inserted in bone, it creates the so-called bone-implant interphase, a joint zone between implant biomaterial surface and the surrounding bone. The healing of this interphase depends on bone biological conditions, characteristic of implant design and the distribution of loads between bone and implant. The aim of present article is to review of healing process of bone-implant interphase for a dental implant and also to describe the sequence of biological events beginning with lesion caused by implant insertion and leading to the formation of a new bone in the interphase. This description includes a novel classification of mechanical phenomena present in the healing

Cochlear Implants

Science.gov (United States)

... implant, including: • How long a person has been deaf, •The number of surviving auditory nerve fibers, and • ... Implant, Severe Sensoryneurial Hearing Loss Get Involved Professional Development Practice Management ENT Careers Marketplace Privacy Policy Terms ...

The Preference of Keeping the Intermediary /y/(ی in Prepositional Construction and Its Attachment to the Silent» h«.

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Mohammad Irani

2010-06-01

Full Text Available Abstract   One of the problems of Persian writing is the question of writing and including the noun or adjective "Prepositional" construction sign in words the written form of which end in a silent » h « which is in fact a short vowel equivalent to /e/ (kasra ـِـ .The difference between the two ways of writing the intermediary consonant /y/( ی at the end of the word with a last silent » h « , completely as « ی » or with the sign « ء» on the silent » h « is rooted in the controversy between the traditional and modern approaches of writing.   The present study is about to study into the following subjects: an analysis and criticism of both the above approaches, a survey of the history of the intermediary /y/( ی , recognizing its phonetic significance and its role in making and adding new syllables, and finally a conclusion about the more convenient way to write it. It is possible that the outcome of the present study will provide us with a unique form of writing of the case in different texts like books, articles, newspapers, journals and electronic texts.

The clinical implications of poly implant prothèse breast implants: an overview.

Science.gov (United States)

Wazir, Umar; Kasem, Abdul; Mokbel, Kefah

2015-01-01

Mammary implants marketed by Poly Implant Prothèse (PIP) were found to contain industrial grade silicone and this caused heightened anxiety and extensive publicity regarding their safety in humans. These implants were used in a large number of patients worldwide for augmentation or breast reconstruction. We reviewed articles identified by searches of Medline, PubMed, Embase, and Google Scholar databases up to May 2014 using the terms: "PIP", "Poly Implant Prothèse", "breast implants" and "augmentation mammoplasty" "siloxanes" or "silicone". In addition the websites of regulating bodies in Europe, USA, and Australia were searched for reports related to PIP mammary implants. PIP mammary implants are more likely to rupture than other implants and can cause adverse effects in the short to the medium term related to the symptoms of rupture such as pain, lumps in the breast and axilla and anxiety. Based on peer-reviewed published studies we have calculated an overall rupture rate of 14.5% (383/2,635) for PIP implants. However, there is no evidence that PIP implant rupture causes long-term adverse health effects in humans so far. Silicone lymphadenopathy represents a foreign body reaction and should be treated conservatively. The long-term adverse effects usually arise from inappropriate extensive surgery, such as axillary lymph node dissection or extensive resection of breast tissue due to silicone leakage.

The Clinical Implications of Poly Implant Prothèse Breast Implants: An Overview

Directory of Open Access Journals (Sweden)

Umar Wazir

2015-01-01

Full Text Available Mammary implants marketed by Poly Implant Prothèse (PIP were found to contain industrial grade silicone and this caused heightened anxiety and extensive publicity regarding their safety in humans. These implants were used in a large number of patients worldwide for augmentation or breast reconstruction. We reviewed articles identified by searches of Medline, PubMed, Embase, and Google Scholar databases up to May 2014 using the terms: "PIP", "Poly Implant Prothèse", "breast implants" and "augmentation mammoplasty" "siloxanes" or "silicone". In addition the websites of regulating bodies in Europe, USA, and Australia were searched for reports related to PIP mammary implants. PIP mammary implants are more likely to rupture than other implants and can cause adverse effects in the short to the medium term related to the symptoms of rupture such as pain, lumps in the breast and axilla and anxiety. Based on peer-reviewed published studies we have calculated an overall rupture rate of 14.5% (383/2,635 for PIP implants. However, there is no evidence that PIP implant rupture causes long-term adverse health effects in humans so far. Silicone lymphadenopathy represents a foreign body reaction and should be treated conservatively. The long-term adverse effects usually arise from inappropriate extensive surgery, such as axillary lymph node dissection or extensive resection of breast tissue due to silicone leakage.

Time-Efficiency Analysis Comparing Digital and Conventional Workflows for Implant Crowns: A Prospective Clinical Crossover Trial.

Science.gov (United States)

Joda, Tim; Brägger, Urs

2015-01-01

To compare time-efficiency in the production of implant crowns using a digital workflow versus the conventional pathway. This prospective clinical study used a crossover design that included 20 study participants receiving single-tooth replacements in posterior sites. Each patient received a customized titanium abutment plus a computer-aided design/computer-assisted manufacture (CAD/CAM) zirconia suprastructure (for those in the test group, using digital workflow) and a standardized titanium abutment plus a porcelain-fused-to-metal crown (for those in the control group, using a conventional pathway). The start of the implant prosthetic treatment was established as the baseline. Time-efficiency analysis was defined as the primary outcome, and was measured for every single clinical and laboratory work step in minutes. Statistical analysis was calculated with the Wilcoxon rank sum test. All crowns could be provided within two clinical appointments, independent of the manufacturing process. The mean total production time, as the sum of clinical plus laboratory work steps, was significantly different. The mean ± standard deviation (SD) time was 185.4 ± 17.9 minutes for the digital workflow process and 223.0 ± 26.2 minutes for the conventional pathway (P = .0001). Therefore, digital processing for overall treatment was 16% faster. Detailed analysis for the clinical treatment revealed a significantly reduced mean ± SD chair time of 27.3 ± 3.4 minutes for the test group compared with 33.2 ± 4.9 minutes for the control group (P = .0001). Similar results were found for the mean laboratory work time, with a significant decrease of 158.1 ± 17.2 minutes for the test group vs 189.8 ± 25.3 minutes for the control group (P = .0001). Only a few studies have investigated efficiency parameters of digital workflows compared with conventional pathways in implant dental medicine. This investigation shows that the digital workflow seems to be more time-efficient than the

Management of peri-implant infections

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K L Vandana

2015-01-01

Full Text Available The ever-increasing popularity of dental implants in recent years has been associated with the reported incidence of short-term and long-term complications such as peri-implant mucositis and peri-implantitis. Therapies proposed for treating peri-implantitis are based on the evidence available for the treatment of periodontitis, and are aimed at reducing the bacterial load within peri-implant pockets and decontaminating implant surfaces, and, in some cases, attempting afterward to bring about bone regeneration. The treatment of peri-implant infections comprises conservative (nonsurgical and surgical approaches. This paper reviews various treatment strategies used for the treatment of peri-implant diseases. There are many approaches suggested by various authors for the treatment of peri-implant diseases, but there is no “ideal peri-implant therapy” that has been described in the literature. There is no consensus regarding the treatment protocol as the studies conducted so far have had varying study designs, small sample sizes, and short follow-up periods.

An in vivo assessment of the effects of using different implant abutment occluding materials on implant microleakage and the peri-implant microbiome

Science.gov (United States)

Rubino, Caroline

Microleakage may be a factor in the progression of peri-implant pathology. Microleakage in implant dentistry refers to the passage of bacteria, fluids, molecules or ions between the abutment-implant interface to and from the surrounding periodontal tissues. This creates a zone of inflammation and reservoir of bacteria at the implant-abutment interface. Bone loss typically occurs within the first year of abutment connection and then stabilizes. It has not yet been definitively proven that the occurrence of microleakage cannot contribute to future bone loss or impede the treatment of peri-implant disease. Therefore, strategies to reduce or eliminate microleakage are sought out. Recent evidence demonstrates that the type of implant abutment channel occluding material can affect the amount of microleakage in an in vitro study environment. Thus, we hypothesize that different abutment screw channel occluding materials will affect the amount of observed microleakage, vis-a-vis the correlation between the microflora found on the abutment screw channel occluding material those found in the peri-implant sulcus. Additional objectives include confirming the presence of microleakage in vivo and assessing any impact that different abutment screw channel occluding materials may have on the peri-implant microbiome. Finally, the present study provides an opportunity to further characterize the peri-implant microbiome. Eight fully edentulous patients restored with at dental implants supporting screw-retained fixed hybrid prostheses were included in the study. At the initial appointment (T1), the prostheses were removed and the implants and prostheses were cleaned. The prostheses were then inserted with polytetrafluoroethylene tape (PTFE, TeflonRTM), cotton, polyvinyl siloxane (PVS), or synthetic foam as the implant abutment channel occluding material and sealed over with composite resin. About six months later (T2), the prostheses were removed and the materials collected. Paper

Biodegradable radioactive implants for glaucoma filtering surgery produced by ion implantation

Energy Technology Data Exchange (ETDEWEB)

Assmann, W. [Department fuer Physik, Ludwig-Maximilians-Universitaet Muenchen, 85748 Garching (Germany)]. E-mail: walter.assmann@lmu.de; Schubert, M. [Department fuer Physik, Ludwig-Maximilians-Universitaet Muenchen, 85748 Garching (Germany); Held, A. [Augenklinik, Technische Universitaet Muenchen, 81675 Munich (Germany); Pichler, A. [Augenklinik, Technische Universitaet Muenchen, 81675 Muenchen (Germany); Chill, A. [Zentralinstitut fuer Medizintechnik, Technische Universitaet Muenchen, 85748 Garching (Germany); Kiermaier, S. [Zentralinstitut fuer Medizintechnik, Technische Universitaet Muenchen, 85748 Garching (Germany); Schloesser, K. [Forschungszentrum Karlsruhe, 76021 Karlsruhe (Germany); Busch, H. [NTTF GmbH, 53619 Rheinbreitbach (Germany); Schenk, K. [NTTF GmbH, 53619 Rheinbreitbach (Germany); Streufert, D. [Acri.Tec GmbH, 16761 Hennigsdorf (Germany); Lanzl, I. [Augenklinik, Technische Universitaet Muenchen, 81675 Munich (Germany)

2007-04-15

A biodegradable, {beta}-emitting implant has been developed and successfully tested which prevents fresh intraocular pressure increase after glaucoma filtering surgery. Ion implantation has been used to load the polymeric implants with the {beta}-emitter {sup 32}P. The influence of ion implantation and gamma sterilisation on degradation and {sup 32}P-fixation behavior has been studied by ion beam and chemical analysis. Irradiation effects due to the applied ion fluence (10{sup 15} ions/cm{sup 2}) and gamma dose (25 kGy) are found to be tolerable.

Trends in cochlear implants.

Science.gov (United States)

Zeng, Fan-Gang

2004-01-01

More than 60,000 people worldwide use cochlear implants as a means to restore functional hearing. Although individual performance variability is still high, an average implant user can talk on the phone in a quiet environment. Cochlear-implant research has also matured as a field, as evidenced by the exponential growth in both the patient population and scientific publication. The present report examines current issues related to audiologic, clinical, engineering, anatomic, and physiologic aspects of cochlear implants, focusing on their psychophysical, speech, music, and cognitive performance. This report also forecasts clinical and research trends related to presurgical evaluation, fitting protocols, signal processing, and postsurgical rehabilitation in cochlear implants. Finally, a future landscape in amplification is presented that requires a unique, yet complementary, contribution from hearing aids, middle ear implants, and cochlear implants to achieve a total solution to the entire spectrum of hearing loss treatment and management.

Micro-cutting of silicon implanted with hydrogen and post-implantation thermal treatment

Science.gov (United States)

Jelenković, Emil V.; To, Suet; Sundaravel, B.; Xiao, Gaobo; Huang, Hu

2016-07-01

It was reported that non-amorphizing implantation by hydrogen has a potential in improving silicon machining. Post-implantation high-temperature treatment will affect implantation-induced damage, which can have impact on silicon machining. In this article, a relation of a thermal annealing of hydrogen implanted in silicon to micro-cutting experiment is investigated. Hydrogen ions were implanted into 4″ silicon wafers with 175 keV, 150 keV, 125 keV and doses of 2 × 1016 cm-2, 2 × 1016 cm-2 and 3 × 1016 cm-2, respectively. In this way, low hydrogen atom-low defect concentration was created in the region less than ~0.8 μm deep and high hydrogen atom-high defect concentration was obtained at silicon depth of ~0.8-1.5 μm. The post-implantation annealing was carried out at 300 and 400 °C in nitrogen for 1 h. Physical and electrical properties of implanted and annealed samples were characterized by secondary ion mass spectroscopy (SIMS), X-ray diffraction (XRD), Rutherford backscattering (RBS) and nanoindentation. Plunge cutting experiment was carried out in and silicon crystal direction. The critical depth of cut and cutting force were monitored and found to be influenced by the annealing. The limits of hydrogen implantation annealing contribution to the cutting characteristics of silicon are discussed in light of implantation process and redistribution of hydrogen and defects generation during annealing process.

Chimeric Peptides as Implant Functionalization Agents for Titanium Alloy Implants with Antimicrobial Properties

Science.gov (United States)

Yucesoy, Deniz T.; Hnilova, Marketa; Boone, Kyle; Arnold, Paul M.; Snead, Malcolm L.; Tamerler, Candan

2015-04-01

Implant-associated infections can have severe effects on the longevity of implant devices and they also represent a major cause of implant failures. Treating these infections associated with implants by antibiotics is not always an effective strategy due to poor penetration rates of antibiotics into biofilms. Additionally, emerging antibiotic resistance poses serious concerns. There is an urge to develop effective antibacterial surfaces that prevent bacterial adhesion and proliferation. A novel class of bacterial therapeutic agents, known as antimicrobial peptides (AMPs), are receiving increasing attention as an unconventional option to treat septic infection, partly due to their capacity to stimulate innate immune responses and for the difficulty of microorganisms to develop resistance towards them. While host and bacterial cells compete in determining the ultimate fate of the implant, functionalization of implant surfaces with AMPs can shift the balance and prevent implant infections. In the present study, we developed a novel chimeric peptide to functionalize the implant material surface. The chimeric peptide simultaneously presents two functionalities, with one domain binding to a titanium alloy implant surface through a titanium-binding domain while the other domain displays an antimicrobial property. This approach gains strength through control over the bio-material interfaces, a property built upon molecular recognition and self-assembly through a titanium alloy binding domain in the chimeric peptide. The efficiency of chimeric peptide both in-solution and absorbed onto titanium alloy surface was evaluated in vitro against three common human host infectious bacteria, Streptococcus mutans, Staphylococcus epidermidis, and Escherichia coli. In biological interactions such as occur on implants, it is the surface and the interface that dictate the ultimate outcome. Controlling the implant surface by creating an interface composed chimeric peptides may therefore

Immediately loaded mini dental implants as overdenture retainers: 1-Year cohort study of implant stability and peri-implant marginal bone level.

Science.gov (United States)

Šćepanović, Miodrag; Todorović, Aleksandar; Marković, Aleksa; Patrnogić, Vesna; Miličić, Biljana; Moufti, Adel M; Mišić, Tijana

2015-05-01

This 1-year cohort study investigated stability and peri-implant marginal bone level of immediately loaded mini dental implants used to retain overdentures. Each of 30 edentulous patients received 4 mini dental implants (1.8 mm × 13 mm) in the interforaminal mandibular region. The implants were immediately loaded with pre-made overdentures. Outcome measures included implant stability and bone resorption. Implant stability was measured using the Periotest Classic(®) device immediately after placement and on the 3rd and 6th weeks and the 4th, 6th and 12th months postoperatively. The peri-implant marginal bone level (PIBL) was evaluated at the implant's mesial and distal sides from the polished platform to the marginal crest. Radiographs were taken using a tailored film holder to reproducibly position the X-ray tube at the 6th week, 4th and 12th months postoperatively. The primary stability (Periotest value, PTV) measured -0.27 ± 3.41 on a scale of -8 to + 50 (lower PTV reflects higher stability). The secondary stability decreased significantly until week 6 (mean PTV = 7.61 ± 7.05) then increased significantly reaching (PTV = 6.17 ± 6.15) at 12 months. The mean PIBL measured -0.40 mm after 1 year of functional loading, with no statistically significant differences at the various follow-ups (p = 0.218). Mini dental implants placed into the interforaminal region could achieve a favorable primary stability for immediate loading. The follow-up Periotest values fluctuated, apparently reflecting the dynamics of bone remodeling, with the implants remaining clinically stable (98.3%) after 1 year of function. The 1-year bone resorption around immediately loaded MDIs is within the clinically acceptable range for standard implants. Copyright © 2014 Elsevier GmbH. All rights reserved.

Comparative silicone breast implant evaluation using mammography, sonography, and magnetic resonance imaging: experience with 59 implants.

Science.gov (United States)

Ahn, C Y; DeBruhl, N D; Gorczyca, D P; Shaw, W W; Bassett, L W

1994-10-01

With the current controversy regarding the safety of silicone implants, the detection and evaluation of implant rupture are causing concern for both plastic surgeons and patients. Our study obtained comparative value analysis of mammography, sonography, and magnetic resonance imaging (MRI) in the detection of silicone implant rupture. Twenty-nine symptomatic patients (total of 59 silicone implants) were entered into the study. Intraoperative findings revealed 21 ruptured implants (36 percent). During physical examination, a positive "squeeze test" was highly suggestive of implant rupture. Mammograms were obtained of 51 implants (sensitivity 11 percent, specificity 89 percent). Sonography was performed on 57 implants (sensitivity 70 percent, specificity 92 percent). MRI was performed on 55 implants (sensitivity 81 percent, specificity 92 percent). Sonographically, implant rupture is demonstrated by the "stepladder sign." Double-lumen implants may appear as false-positive results for rupture on sonography. On MRI, the "linguine sign" represents disrupted fragments of a ruptured implant. The most reliable imaging modality for implant rupture detection is MRI, followed by sonogram. Mammogram is the least reliable. Our study supports the clinical indication and diagnostic value of sonogram and MRI in the evaluation of symptomatic breast implant patients.

The Efficacy of Supportive Peri-Implant Therapies in Preventing Peri-Implantitis and Implant Loss: a Systematic Review of the Literature

Directory of Open Access Journals (Sweden)

Ausra Ramanauskaite

2016-09-01

Full Text Available Objectives: To study the efficacy of supportive peri-implant therapies in preventing clinical and radiological signs of peri-implantitis and implant loss. Material and Methods: Longitudinal human studies, published between January 1, 2006, and February 1, 2016, were included based on an electronic search using MEDLINE and EMBASE databases and complemented by a manual search. Articles were included only if 1 they comprised a group of patients involved in/adhering to regular supportive peri-implant therapies (SPTs and a control group without such therapies or with poor adherence to them, 2 the protocol of the SPTs was clearly described and 3 the outcome was indicated by means of clinical/radiological changes or implant loss. Results: After initially identifying a total of 710 titles and abstracts, 12 full text articles were selected for eligibility assessment. Seven studies, three prospective and four retrospective, fulfilled the inclusion criteria for this review. The frequency of recall visits varied between the studies from a minimum of one visit every three months to an individually tailored regimen. In all the studies a lack of SPTs or poor adherence to them resulted in significantly higher frequencies of sites with mucosal bleeding, deepened peri-implant pockets or alveolar bone loss. In line with the above, a lack of/poor adherence to SPTs was associated with higher implant loss. Conclusions: To prevent peri-implantitis, an individually tailored supportive programme based on patient motivation and re-instruction in oral hygiene measures combined with professional implant cleaning seem to be crucial.

Benefits and Risks of Cochlear Implants

Science.gov (United States)

... and Medical Procedures Implants and Prosthetics Cochlear Implants Benefits and Risks of Cochlear Implants Share Tweet Linkedin ... the Use of Cochlear Implants What are the Benefits of Cochlear Implants? For people with implants: Hearing ...

An economic evaluation of maxillary implant overdentures based on six vs. four implants.

Science.gov (United States)

Listl, Stefan; Fischer, Leonhard; Giannakopoulos, Nikolaos Nikitas

2014-08-18

The purpose of the present study was to assess the value for money achieved by bar-retained implant overdentures based on six implants compared with four implants as treatment alternatives for the edentulous maxilla. A Markov decision tree model was constructed and populated with parameter estimates for implant and denture failure as well as patient-centred health outcomes as available from recent literature. The decision scenario was modelled within a ten year time horizon and relied on cost reimbursement regulations of the German health care system. The cost-effectiveness threshold was identified above which the six-implant solution is preferable over the four-implant solution. Uncertainties regarding input parameters were incorporated via one-way and probabilistic sensitivity analysis based on Monte-Carlo simulation. Within a base case scenario of average treatment complexity, the cost-effectiveness threshold was identified to be 17,564 € per year of denture satisfaction gained above of which the alternative with six implants is preferable over treatment including four implants. Sensitivity analysis yielded that, depending on the specification of model input parameters such as patients' denture satisfaction, the respective cost-effectiveness threshold varies substantially. The results of the present study suggest that bar-retained maxillary overdentures based on six implants provide better patient satisfaction than bar-retained overdentures based on four implants but are considerably more expensive. Final judgements about value for money require more comprehensive clinical evidence including patient-centred health outcomes.

Unrecoverable bi-products of drilling titanium alloy and tantalum metal implants: a pilot study.

Science.gov (United States)

Skowronek, Paweł; Olszewski, Paweł; Święszkowski, Wojciech; Synder, Marek; Sibiński, Marcin; Mazek, Jacek

2018-05-01

Trabecular metal implants with a porous architecture that allows for the incorporation of bone into the implant during healing are gaining popularity in alloplastic revision procedures. The bi-products of drilling titanium alloy (Ti) and tantalum (Ta) implants have not been previously assessed. Four holes were drilled in each of two spatially porous trabecular implants, one Ta and the other Ti alloy (Ti-6Al-7Nb), for this pilot in vitro study. The particles were flushed out with a continuous flow of saline. The particles' weight and the volume were then measured using a Radwag XA 110/2X (USA) laboratory balance. The total volume of the obtained metal fines was measured by titration using a 10 mm 3 measurement system. A cobalt carbide bit was used since the holes could not be made with a standard bone drill. Each Ti and Ta implant lost 1.26 g and 2.48 g of mass, respectively. The volume of free particles recovered after each stage was 280 mm 3 and 149 mm 3 , respectively. Approximately 0.6% of the total implant mass was not recovered after drilling (roughly 2% of the mass of the particles created by drilling), despite the use of 5 µm filters. It is technically difficult to drill holes in Ti and Ta implants using standard surgical tools. The drilling process creates a considerable amount of metal particles, which cannot be recovered despite intensive flushing. This may have an adverse influence on the bio-functionality (survival) of the endoprosthesis and present deleterious systemic consequences.

Is bruxism a risk factor for dental implants? A systematic review of the literature.

Science.gov (United States)

Manfredini, Daniele; Poggio, Carlo E; Lobbezoo, Frank

2014-06-01

To systematically review the literature on the role of bruxism as a risk factor for the different complications on dental implant-supported rehabilitations. A systematic search in the National Library of Medicine's Medline Database was performed to identify all peer-reviewed papers in the English literature assessing the role of bruxism, as diagnosed with any other diagnostic approach (i.e., clinical assessment, questionnaires, interviews, polysomnography, and electromyography), as a risk factor for biological (i.e., implant failure, implant mobility, and marginal bone loss) or mechanical (i.e., complications or failures of either prefabricated components or laboratory-fabricated suprastructures) complications on dental implant-supported rehabilitations. The selected articles were reviewed according to a structured summary of the articles in relation to four main issues, viz., "P" - patients/problem/population, "I" - intervention, "C" - comparison, and "O" - outcome. A total of 21 papers were included in the review and split into those assessing biological complications (n = 14) and those reporting mechanical complications (n = 7). In general, the specificity of the literature for bruxism diagnosis and for the study of the bruxism's effects on dental implants was low. From a biological viewpoint, bruxism was not related with implant failures in six papers, while results from the remaining eight studies did not allow drawing conclusions. As for mechanical complications, four of the seven studies yielded a positive relationship with bruxism. Bruxism is unlikely to be a risk factor for biological complications around dental implants, while there are some suggestions that it may be a risk factor for mechanical complications. © 2012 Wiley Periodicals, Inc.

[Researches on biomechanics of micro-implant-bone interface and optimum design of micro implant's neck].

Science.gov (United States)

Deng, Feng; Zhang, Lei; Zhang, Yi; Song, Jin-lin; Fan, Yuboa

2007-07-01

To compare and analyze the stress distribution at the micro-implant-bone interface based on the different micro-implant-bone conditioned under orthodontic load, and to optimize the design of micro implant's neck. An adult skull with all tooth was scanned by spiral CT, and the data were imported into computer for three-dimensional reconstruction with software Mimics 9.0. The three dimensional finite element models of three micro-implant-bone interfaces(initial stability, full osseointegration and fibrous integration) were analyzed by finite element analysis software ABAQUS6.5. The primary stress distributions of different micro-implant-bone conditions were evaluated when 2N force was loaded. Then the diameter less than 1.5 mm of the micro implant's neck was added with 0.2 mm, to compare the stress distribution of the modified micro-implant-bone interface with traditional type. The stress mostly concentrated on the neck of micro implant and the full osseointegration interface in all models showed the lowest strain level. Compared with the traditional type, the increasing diameter neck of the micro implant obviously decreased the stress level in all the three conditions. The micro-implant-bone interface and the diameter of micro implant's neck both are the important influence factors to the stress distribution of micro implant.

Implant Mandibular Overdentures Retained by Immediately Loaded Implants: A 1-Year Randomized Trial Comparing the Clinical and Radiographic Outcomes Between Mini Dental Implants and Standard-Sized Implants.

Science.gov (United States)

Zygogiannis, Kostas; Aartman, Irene Ha; Parsa, Azin; Tahmaseb, Ali; Wismeijer, Daniel

The aim of this 1-year randomized trial was to evaluate and compare the clinical and radiographic performance of four immediately loaded mini dental implants (MDIs) and two immediately loaded standard-sized tissue-level (STL) implants, placed in the interforaminal region of the mandible and used to retain mandibular overdentures (IODs) in completely edentulous patients. A total of 50 completely edentulous patients wearing conventional maxillary dentures and complaining about insufficient retention of their mandibular dentures were divided into two groups; 25 patients received four MDIs and 25 patients received two STL implants. The marginal bone loss (MBL) at the mesial and distal sides of each implant was assessed by means of standardized intraoral radiographs after a period of 1 year. Implant success and survival rates were also calculated. Immediate loading was possible for all patients in the first group. In the second group, an immediate loading protocol could not be applied for 10 patients. These patients were treated with a delayed loading protocol. A mean MBL of 0.42 ± 0.56 mm for the MDIs and 0.54 ± 0.49 mm for the immediately loaded STL implants was recorded at the end of the evaluation period. There was no statistically significant difference between the MDIs and the immediately loaded STL implants. Two MDIs failed, resulting in a survival rate of 98%. The success rate was 91%. For the immediately loaded conventional implants, the survival rate was 100% and the success rate 96.7% after 1 year of function. However, in 10 patients, the immediate loading protocol could not be followed. Considering the limitations of this short-term clinical study, immediate loading of four unsplinted MDIs or two splinted STL implants to retain mandibular overdentures seems to be a feasible treatment option. The marginal bone level changes around the MDIs were well within the clinically acceptable range.

Implant decontamination with phosphoric acid during surgical peri-implantitis treatment : a RCT

NARCIS (Netherlands)

Hentenaar, Diederik F M; De Waal, Yvonne C M; Strooker, Hans; Meijer, Henny J A; Van Winkelhoff, Arie-Jan; Raghoebar, Gerry M

2017-01-01

BACKGROUND: Peri-implantitis is known as an infectious disease that affects the peri-implant soft and hard tissue. Today, scientific literature provides very little evidence for an effective intervention protocol for treatment of peri-implantitis. The aim of the present randomized controlled trial

Randomized study on the effect of single-implant versus two-implant retained overdentures on implant loss and muscle activity: a 12-month follow-up report.

Science.gov (United States)

Alqutaibi, A Y; Kaddah, A F; Farouk, M

2017-06-01

The objective was to evaluate and compare single- and two-implant retained overdentures for the rehabilitation of the edentulous mandible. Fifty-six edentulous subjects were eligible for inclusion. Using a random sampling system, a single implant or two implants were placed in the mandible. After 3 months, locator attachments were connected to the implants and the denture delivered with the retentive components incorporated in the denture base. Implant failure and muscle activity were evaluated at the 3-, 6-, and 12-month follow-up examinations. The study sample comprised 56 patients (32 male, 24 female), with a mean age of 58.2 years. A total of 84 implants were placed (28 in the single-implant group and 56 in the two-implant group). All patients completed the 12 months of follow-up. No significant differences were found between subjects in the two groups with respect to implant failure. With regard to improvements in muscle activity, the two-implant group showed statistically significant but perhaps not clinically important differences. Single-implant mandibular overdentures may be suggested as an alternative treatment modality for the rehabilitation of edentulous patients who cannot afford the cost of a two-implant overdenture. Copyright © 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Plasma-implantation-based surface modification of metals with single-implantation mode

Science.gov (United States)

Tian, X. B.; Cui, J. T.; Yang, S. Q.; Fu, Ricky K. Y.; Chu, Paul K.

2004-12-01

Plasma ion implantation has proven to be an effective surface modification technique. Its biggest advantage is the capability to treat the objects with irregular shapes without complex manipulation of target holder. Many metal materials such as aluminum, stainless steel, tool steel, titanium, magnesium etc, has been treated using this technique to improve their wear-resistance, corrosion-resistance, fatigue-resistance, oxidation-resistance, bio-compatiblity etc. However in order to achieve thicker modified layers, hybrid processes combining plasma ion implantation with other techniques have been frequently employed. In this paper plasma implantation based surface modification of metals using single-implantation mode is reviewed.

The Cardiomyocyte RNA-Binding Proteome: Links to Intermediary Metabolism and Heart Disease

Directory of Open Access Journals (Sweden)

Yalin Liao

2016-08-01

Full Text Available RNA functions through the dynamic formation of complexes with RNA-binding proteins (RBPs in all clades of life. We determined the RBP repertoire of beating cardiomyocytic HL-1 cells by jointly employing two in vivo proteomic methods, mRNA interactome capture and RBDmap. Together, these yielded 1,148 RBPs, 391 of which are shared with all other available mammalian RBP repertoires, while 393 are thus far unique to cardiomyocytes. RBDmap further identified 568 regions of RNA contact within 368 RBPs. The cardiomyocyte mRNA interactome composition reflects their unique biology. Proteins with roles in cardiovascular physiology or disease, mitochondrial function, and intermediary metabolism are all highly represented. Notably, we identified 73 metabolic enzymes as RBPs. RNA-enzyme contacts frequently involve Rossmann fold domains with examples in evidence of both, mutual exclusivity of, or compatibility between RNA binding and enzymatic function. Our findings raise the prospect of previously hidden RNA-mediated regulatory interactions among cardiomyocyte gene expression, physiology, and metabolism.

Impact of an implanted neuroprosthesis on community ambulation in incomplete SCI.

Science.gov (United States)

Lombardo, Lisa M; Kobetic, Rudolf; Pinault, Gilles; Foglyano, Kevin M; Bailey, Stephanie N; Selkirk, Stephen; Triolo, Ronald J

2018-03-01

Test the effect of a multi-joint control with implanted electrical stimulation on walking after spinal cord injury (SCI). Single subject research design with repeated measures. Hospital-based biomechanics laboratory and user assessment of community use. Female with C6 AIS C SCI 30 years post injury. Lower extremity muscle activation with an implanted pulse generator and gait training. Walking speed, maximum distance, oxygen consumption, upper extremity (UE) forces, kinematics and self-assessment of technology. Short distance walking speed at one-year follow up with or without stimulation was not significantly different from baseline. However, average walking speed was significantly faster (0.22 m/s) with stimulation over longer distances than volitional walking (0.12 m/s). In addition, there was a 413% increase in walking distance from 95 m volitionally to 488 m with stimulation while oxygen consumption and maximum upper extremity forces decreased by 22 and 16%, respectively. Stimulation also produced significant (P ≤ 0.001) improvements in peak hip and knee flexion, ankle angle at foot off and at mid-swing. An implanted neuroprosthesis enabled a subject with incomplete SCI to walk longer distances with improved hip and knee flexion and ankle dorsiflexion resulting in decreased oxygen consumption and UE support. Further research is required to determine the robustness, generalizability and functional implications of implanted neuroprostheses for community ambulation after incomplete SCI.

The laboratories of geological studies; Les laboratoires d`etudes geologiques

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-01-01

This educational document comprises 4 booklets in a folder devoted to the presentation of the ANDRA`s activities in geological research laboratories. The first booklet gives a presentation of the missions of the ANDRA (the French agency for the management of radioactive wastes) in the management of long life radioactive wastes. The second booklet describes the approach of waste disposal facilities implantation. The third booklet gives a brief presentation of the scientific program concerning the underground geologic laboratories. The last booklet is a compilation of questions and answers about long-life radioactive wastes, the research and works carried out in geologic laboratories, the public information and the local socio-economic impact, and the storage of radioactive wastes in deep geological formations. (J.S.)

Influence of prosthesis design and implantation technique on implant stresses after cementless revision THR

Directory of Open Access Journals (Sweden)

Duda Georg N

2011-05-01

Full Text Available Abstract Background Femoral offset influences the forces at the hip and the implant stresses after revision THR. For extended bone defects, these forces may cause considerable bending moments within the implant, possibly leading to implant failure. This study investigates the influences of femoral anteversion and offset on stresses in the Wagner SL revision stem implant under varying extents of bone defect conditions. Methods Wagner SL revision stems with standard (34 mm and increased offset (44 mm were virtually implanted in a model femur with bone defects of variable extent (Paprosky I to IIIb. Variations in surgical technique were simulated by implanting the stems each at 4° or 14° of anteversion. Muscle and joint contact forces were applied to the reconstruction and implant stresses were determined using finite element analyses. Results Whilst increasing the implant's offset by 10 mm led to increased implant stresses (16.7% in peak tensile stresses, altering anteversion played a lesser role (5%. Generally, larger stresses were observed with reduced bone support: implant stresses increased by as much as 59% for a type IIIb defect. With increased offset, the maximum tensile stress was 225 MPa. Conclusion Although increased stresses were observed within the stem with larger offset and increased anteversion, these findings indicate that restoration of offset, key to restoring joint function, is unlikely to result in excessive implant stresses under routine activities if appropriate fixation can be achieved.

Expressive Language Development in 45 Cochlear Implanted Children Following 2 Years of Implantation

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Seyed Basir Hashemi

2011-10-01

Full Text Available Objectives: Profound hearing loss encounters children with delay in speech and language. As it is known language acquisition in young deaf children is a lengthy process, but cochlear implanted children have better spoken language skills than if they had not received the device. According to the importance of cochlear implant in deaf child's language development, this study evaluates the effect of different variables on child's language performance. Methods: 45 cochlear implanted children were tested, all of whom had used the device for at least 2 years. In order to evaluate the children, the NEWSHA test which is fitted for Persian speaking children was performed and language development of the children was compared through stepwise discriminant analysis. Results: After evaluation of the effect of different variables like child's age of implantation, participating in rehabilitation classes, parent's cooperation and their level of education, we came to a conclusion that the child's age of implantation and rehabilitation program significantly develop the child's language performance. Discussion: The value of cochlear implant in improvement of deaf children in speech, language perception, production and comprehension is confirmed by different studies which have been done on cochlear implanted children. Also, the present study indicates that language development in cochlear implanted children is highly related to their age of implantation and rehabilitation program.

Optical effects of ion implantation

International Nuclear Information System (INIS)

Townsend, P.D.

1987-01-01

The review concerns the effects of ion implantation that specifically relate to the optical properties of insulators. Topics which are reviewed include: ion implantation, ion range and damage distributions, colour centre production by ion implantation, high dose ion implantation, and applications for integrated optics. Numerous examples are presented of both diagnostic and industrial examples of ion implantation effects in insulators. (U.K.)

Effect of healing time on bone-implant contact of orthodontic micro-implants: a histologic study.

Science.gov (United States)

Ramazanzadeh, Barat Ali; Fatemi, Kazem; Dehghani, Mahboobe; Mohtasham, Nooshin; Jahanbin, Arezoo; Sadeghian, Hamed

2014-01-01

Objectives. This study aimed to evaluate the effect of immediate and delayed loading of orthodontic micro-implants on bone-implant contact. Materials and Methods. Sixty four micro-implants were implanted in dog's jaw bone. The micro-implants were divided into loaded and unloaded (control) groups. The control group had two subgroups: four and eight weeks being implanted. The loaded group had two subgroups of immediate loading and delayed (after four weeks healing) loading. Loaded samples were subjected to 200g load for four weeks. After sacrificing the animals micro-implants and surrounding tissues were observed histologically. Bone-implant contact ratios (BIC) were calculated and different groups' results were compared by three-way ANOVA. Results. Mean survival rate was 96.7% in general. Survival rates were 96.7%, 94.4% and 100% for control, immediate and delayed loaded groups, respectively. BIC values were not significantly different in loaded and control groups, immediate and delayed loading groups, and pressure and tension sides. Mandibular micro-implants had significantly higher BIC than maxillary ones in immediate loading, 4-weeks control, and 8-weeks control groups (P = 0.021, P = 0.009, P = 0.003, resp.). Conclusion Immediate or delayed loading of micro-implants in dog did not cause significant difference in Bone-implant contact which could be concluded that healing time had not significant effect on micro-implant stability.

Implant-supported mandibular removable partial dentures; patient-based outcome measures in relation to implant position.

Science.gov (United States)

Jensen, Charlotte; Raghoebar, Gerry M; Kerdijk, Wouter; Meijer, Henny J A; Cune, Marco S

2016-12-01

To assess the benefits of implant support to Removable Partial Dentures (RPD) in patients with a bilateral free-ending situation in the mandible and to determine the most favorable implant position: the premolar (PM) or the molar (M) region. Thirty subjects with a bilateral unbounded posterior saddle received 2 PM and 2M implants. A new RPD was placed. Implant support was provided 3 months later. Two PM implants supported the RPD. After 3 months the 2M implants were used or vice versa. Outcome measures included oral health related quality of life (OHIP-NL49), general health status (SF-36), contentment assessed on a Visual Analogue Scale (VAS) and the number of hours that the RPD was worn. Data were collected prior to treatment, 3 months after having functioned with a new RPD and after 3 and 6 months with implant support. Finally, patients expressed their preferred implant position. The general health status (SF-36) was not influenced. OHIP-NL49 values and mean wearing-time were statistical significantly more favorable for ISRPD's, regardless of the implant position. Per day, the ISRPD's were worn 2-3h more than the unsupported new RPD. Patients' expectations were met as the VAS-scores of anticipated and realized contentment did not reach a statistical significant level (p>0.05). VAS scores for ISRPD's with M implant support were higher than for PM implant support. Finally, 56.7% of subjects preferred the M implant support, 13.3% expressed no preference and 30% opted for PM implant support. Mandibular implant support favorably influences oral health related patient-based outcome measures in patients with a bilateral free-ending situation. The majority of patients prefer the implant support to be in the molar region. Patients with a bilateral free-ending situation in the mandible opposed by a maxillary denture benefit from implant support to their mandibular removable partial denture. Most patients prefer this support to be in the molar region. Copyright © 2016

Rehabilitación sobre implantes oseointegrados A case with rehabilitation on boneintegrated implants

Directory of Open Access Journals (Sweden)

Leticia María Lemus Cruz

2009-03-01

Full Text Available Se presenta un caso de un paciente rehabilitado en la consulta de Implantología de la Facultad de Estomatología de Ciudad de La Habana. La historia de la implantología moderna se remonta a principios de los años 60, cuando Per-Ingvar Branemark sienta las bases de la osteointegración y describe los primeros implantes de titanio con forma de tornillo. Aunque antigua, es la prótesis más moderna. Si la meticulosidad es obligada en la elaboración de todo tipo de prótesis, en los trabajos de implantes no se admite el más mínimo fallo, desde la planificación del caso hasta la implantación de la prótesis en boca. Para obtener buenos resultados, las técnicas y los procesos han de observarse escrupulosamente. En nuestra Facultad se ha creado el Grupo de Implantología, que es el encargado de la colocación de implantes y la rehabilitación prótesica de estos. Para ello han sido utilizado diferentes tipos de implantes comercializados y patentizados al nivel mundial. Se reafirma que la rehabilitación sobre implantes mejora la calidad estética y funcional de los pacientes.A case of rehabilitation patient is presented seen in Implantation Science consulting room of Stomatology Faculty of Havana City. History of implantation science dates back to at the beginning of 60s, when Per-Ingvar Branemark creates the bases of bone-integration and to describe the firsts titanium implants in a screw form. Although ancient, it is the more modern prosthesis. If meticulousness if mandatory in elaboration of all type of prosthesis, in implants works it inadmissible the minimum of failure, from the case planning until prosthesis implantation in mouth. To achieve good results, techniques and processes has to be scrupulously observed. In our Faculty it has been created a group of Implantation Science, which is in charge of implants placement, and of the prosthetic rehabilitation of these. Thus, we used different types of marketed and showed at world level. It

Recent developments in the United Kingdom in ion implantation equipment for engineering components

International Nuclear Information System (INIS)

Gardner, P.R.

1988-01-01

Harwell has been particularly active in the development and commercial exploitation of low-cost, rugged, reliable and simple-to-operate equipment for implantation of engineering components with gaseous ions, especially nitrogen. Laboratory experiments show this to reduce mild abrasive wear in a wide range of materials by factors typically 2-10, provided operating temperatures remain below about 400 deg C. The latest nitrogen ion implantation machine (the Tecvac 221 model) embodies a substantial degree of flexibility, with cable-mounted ion sources and demountable target chambers. This enables wide ranges of workpiece size and shape to be accommodated. The latest development at Harwell is the large 'Blue Tank' ion implantation machine, currently the biggest in the world. This can treat workpieces up to 2 metres maximum dimension and 1 tonne weight using a bucket-type ion source capable of generating 35 mA of nitrogen ion beam current over an 800 mm diameter treatment area. This machine enables increased flexibility and reduced unit treatment costs for nitrogen ion implantation. Uptake of nitrogen ion implantation in British industry is increasing steadily. Key market sectors include the plastics processing industry (for extrusion screws, moulds and dies), as well as many other engineering sectors. A useful accessory to ion implantation developed at Harwell in conjunction with Millspin Limited, monitors nitrogen ion dose colour changes in anodised tantalum which can be compared against a calibrated standard. Accuracies of around 20 % at 2.5 x 10 17 nitrogen ions.cm -2 dose are achievable. (J.P.N.)

Implant-supported mandibular removable partial dentures: Functional, clinical and radiographical parameters in relation to implant position.

Science.gov (United States)

Jensen, Charlotte; Speksnijder, Caroline M; Raghoebar, Gerry M; Kerdijk, Wouter; Meijer, Henny J A; Cune, Marco S

2017-06-01

Patients with a Kennedy class I situation often encounter problems with their removable partial denture (RPD). To assess the functional benefits of implant support to RPDs, the clinical performance of the implants and teeth and to determine the most favorable implant position: the premolar (PM) or molar (M) region. Thirty subjects received 2 PM and 2 M implants. A new RPD was made. Implant support was provided 3 months later. In a cross-over model, randomly, 2 implants (PM or M) supported the RPD during 3 months. Masticatory performance was assessed using the mixing ability index (MAI). Clinical and radiographic parameters were assessed. Non-parametric statistical analysis for related samples and post hoc comparisons were performed. Masticatory performance differed significantly between the stages of treatment (P < .001). MAI-scores improved with implant support although the implant position had no significant effect. No complications to the implants or RPD were observed and clinical and radiographical parameters for both implants and teeth were favorable. Higher scores for bleeding on probing were seen for molar implants. Implant support to a Kennedy class I RPD significantly improves masticatory function, regardless of implant position. No major clinical problems were observed. © 2017 Wiley Periodicals, Inc.

Nitrogen implantation in tungsten and migration in the fusion experiment ASDEX upgrade

International Nuclear Information System (INIS)

Meisl, Gerd Korbinian

2015-01-01

The implantation of nitrogen ions into tungsten was studied in laboratory experiments to understand the interaction of nitrogen containing fusion plasmas with tungsten walls. The resulting model of W-N interaction was tested by experiments in the tokamak ASDEX Upgrade. Using the measurements from these experiments as boundary condition, nitrogen transport and re-distribution in the plasma were modeled by self-consistent WallDYN-DIVIMP simulations.

Clinical evaluation of music perception, appraisal and experience in cochlear implant users.

Science.gov (United States)

Drennan, Ward R; Oleson, Jacob J; Gfeller, Kate; Crosson, Jillian; Driscoll, Virginia D; Won, Jong Ho; Anderson, Elizabeth S; Rubinstein, Jay T

2015-02-01

The objectives were to evaluate the relationships among music perception, appraisal, and experience in cochlear implant users in multiple clinical settings and to examine the viability of two assessments designed for clinical use. Background questionnaires (IMBQ) were administered by audiologists in 14 clinics in the United States and Canada. The CAMP included tests of pitch-direction discrimination, and melody and timbre recognition. The IMBQ queried users on prior musical involvement, music listening habits pre and post implant, and music appraisals. One-hundred forty-five users of Advanced Bionics and Cochlear Ltd cochlear implants. Performance on pitch direction discrimination, melody recognition, and timbre recognition tests were consistent with previous studies with smaller cohorts, as well as with more extensive protocols conducted in other centers. Relationships between perceptual accuracy and music enjoyment were weak, suggesting that perception and appraisal are relatively independent for CI users. Perceptual abilities as measured by the CAMP had little to no relationship with music appraisals and little relationship with musical experience. The CAMP and IMBQ are feasible for routine clinical use, providing results consistent with previous thorough laboratory-based investigations.

Scalloped Implant-Abutment Connection Compared to Conventional Flat Implant-Abutment Connection: a Systematic Review and Meta-Analysis.

Science.gov (United States)

Starch-Jensen, Thomas; Christensen, Ann-Eva; Lorenzen, Henning

2017-01-01

The objective was to test the hypothesis of no difference in implant treatment outcome after installation of implants with a scalloped implant-abutment connection compared to a flat implant-abutment connection. A MEDLINE (PubMed), Embase and Cochrane library search in combination with a hand-search of relevant journals was conducted. No language or year of publication restriction was applied. The search provided 298 titles. Three studies fulfilled the inclusion criteria. The included studies were characterized by low or moderate risk of bias. Survival of suprastructures has never been compared within the same study. High implant survival rate was reported in all the included studies. Significantly more peri-implant marginal bone loss, higher probing depth score, bleeding score and gingival score was observed around implants with a scalloped implant-abutment connection. There were no significant differences between the two treatment modalities regarding professional or patient-reported outcome measures. Meta-analysis disclosed a mean difference of peri-implant marginal bone loss of 1.56 mm (confidence interval: 0.87 to 2.25), indicating significant more bone loss around implants with a scalloped implant-abutment connection. A scalloped implant-abutment connection seems to be associated with higher peri-implant marginal bone loss compared to a flat implant-abutment connection. Therefore, the hypothesis of the present systematic review must be rejected. However, further long-term randomized controlled trials assessing implant treatment outcome with the two treatment modalities are needed before definite conclusions can be provided about the beneficial use of implants with a scalloped implant-abutment connection on preservation of the peri-implant marginal bone level.

A prospective, split-mouth study comparing tilted implants with angulated connection versus conventional implants with angulated abutment.

Science.gov (United States)

Van Weehaeghe, Manú; De Bruyn, Hugo; Vandeweghe, Stefan

2017-12-01

An angulation of the implant connection could overcome the problems related to angulated abutments. This study compares conventional implants with angulated abutment to tilted implants with an angulated connection. Twenty patients were treated in the edentulous mandible. In the posterior jaw locations, one conventional tilted implant with angulated abutment and one angulated implant without abutment were placed. In the anterior jaw, two conventional implants were placed, one with and one without abutment. Implants were immediately loaded and 3 months later, the final bridge (PFM or monolithic zirconia) was placed. After a follow-up of 48 months, 17 patients were available for clinical examination. The mean overall marginal bone loss (MBL) was 1.26 mm. No significant differences in implant survival, MBL, periodontal indices, patients' satisfaction, or complications was found between implants restored on abutment or implant level, between the posteriorly located angulated implant nor angulated abutment, and between both anterior implants with or without abutment. The posterior implants demonstrated less MBL compared to the anterior implants (P abutment were replaced and four loose bridge screws connected to the angulated abutments had to be tightened. Patients were overall satisfied (4.74/5). An implant with angulated connection may results in a stronger connection but does not affect the marginal bone loss. No difference in MBL was seen between implants restored on abutment or implant level. Zirconia seems to reduce the amount of plaque. © 2017 Wiley Periodicals, Inc.

Risk of pacemaker implantation after uneventful successful cavotricuspid isthmus radiofrequency ablation in patients with common atrial flutter.

Science.gov (United States)

Rodríguez-Mañero, Moisés; González-Melchor, Layla; Ballesteros, Gabriel; Raposeiras-Roubín, Sergio; García-Seara, Javier; López, Xesús Alberte Fernández; Cambeiro, Cristina González; Alcalde, Oscar; García-Bolao, Ignacio; Martínez-Sande, Luis; González-Juanatey, José Ramón

2016-01-01

Little is known about the risk of pacemaker implantation after common atrial flutter ablation in the long-term. We retrospectively reviewed the electrophysiology laboratory database at two Spanish University Hospitals from 1998 to 2012 to identify patients who had undergone successful ablation for cavotricuspid dependent atrial flutter. Cox regression analysis was used to examine the risk of pacemaker implantation. A total of 298 patients were considered eligible for inclusion. The mean age of the enrolled patients was 65.7±11. During 57.7±42.8 months, 30 patients (10.1%) underwent pacemaker implantation. In the stepwise multivariate models only heart rate at the time of the ablation (OR: 0.96; 95% CI: 0.93-0.98; ppacemaker implantation. A heart rate of ≤65 bpm was identified as the optimal cut-off value to predict the need of pacemaker implantation in the follow-up (sensitivity: 79%, specificity: 74%) by ROC curve analyses. This is the first study of an association between the slow conducting common atrial flutter and subsequent risk of pacemaker implantation. In light of these findings, assessing it prior to ablation can be helpful for the risk stratification of sinus node disease or atrioventricular conduction disease requiring a pacemaker implantation in patients with persistent atrial flutter. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Quantitative ion implantation

International Nuclear Information System (INIS)

Gries, W.H.

1976-06-01

This is a report of the study of the implantation of heavy ions at medium keV-energies into electrically conducting mono-elemental solids, at ion doses too small to cause significant loss of the implanted ions by resputtering. The study has been undertaken to investigate the possibility of accurate portioning of matter in submicrogram quantities, with some specific applications in mind. The problem is extensively investigated both on a theoretical level and in practice. A mathematical model is developed for calculating the loss of implanted ions by resputtering as a function of the implanted ion dose and the sputtering yield. Numerical data are produced therefrom which permit a good order-of-magnitude estimate of the loss for any ion/solid combination in which the ions are heavier than the solid atoms, and for any ion energy from 10 to 300 keV. The implanted ion dose is measured by integration of the ion beam current, and equipment and techniques are described which make possible the accurate integration of an ion current in an electromagnetic isotope separator. The methods are applied to two sample cases, one being a stable isotope, the other a radioisotope. In both cases independent methods are used to show that the implantation is indeed quantitative, as predicted. At the same time the sample cases are used to demonstrate two possible applications for quantitative ion implantation, viz. firstly for the manufacture of calibration standards for instrumental micromethods of elemental trace analysis in metals, and secondly for the determination of the half-lives of long-lived radioisotopes by a specific activity method. It is concluded that the present study has advanced quantitative ion implantation to the state where it can be successfully applied to the solution of problems in other fields

Impact of cone-beam computed tomography on implant planning and on prediction of implant size

International Nuclear Information System (INIS)

Pedroso, Ludmila Assuncao de Mello; Silva, Maria Alves Garcia Santos; Garcia, Robson Rodrigues; Leles, Jose Luiz Rodrigues; Leles, Claudio Rodrigues

2013-01-01

The aim was to investigate the impact of cone-beam computed tomography (CBCT) on implant planning and on prediction of final implant size. Consecutive patients referred for implant treatment were submitted to clinical examination, panoramic (PAN) radiography and a CBCT exam. Initial planning of implant length and width was assessed based on clinical and PAN exams, and final planning, on CBCT exam to complement diagnosis. The actual dimensions of the implants placed during surgery were compared with those obtained during initial and final planning, using the McNemmar test (p 0.05). It was concluded that CBCT improves the ability of predicting the actual implant length and reduces inaccuracy in surgical dental implant planning. (author)

In Vivo Response of Laser Processed Porous Titanium Implants for Load-Bearing Implants.

Science.gov (United States)

Bandyopadhyay, Amit; Shivaram, Anish; Tarafder, Solaiman; Sahasrabudhe, Himanshu; Banerjee, Dishary; Bose, Susmita

2017-01-01

Applications of porous metallic implants to enhance osseointegration of load-bearing implants are increasing. In this work, porous titanium implants, with 25 vol.% porosity, were manufactured using Laser Engineered Net Shaping (LENS™) to measure the influence of porosity towards bone tissue integration in vivo. Surfaces of the LENS™ processed porous Ti implants were further modified with TiO 2 nanotubes to improve cytocompatibility of these implants. We hypothesized that interconnected porosity created via additive manufacturing will enhance bone tissue integration in vivo. To test our hypothesis, in vivo experiments using a distal femur model of male Sprague-Dawley rats were performed for a period of 4 and 10 weeks. In vivo samples were characterized via micro-computed tomography (CT), histological imaging, scanning electron microscopy, and mechanical push-out tests. Our results indicate that porosity played an important role to establish early stage osseointegration forming strong interfacial bonding between the porous implants and the surrounding tissue, with or without surface modification, compared to dense Ti implants used as a control.

In vivo response of laser processed porous titanium implants for load-bearing implants

Science.gov (United States)

Bandyopadhyay, Amit; Shivaram, Anish; Tarafder, Solaiman; Sahasrabudhe, Himanshu; Banerjee, Dishary; Bose, Susmita

2016-01-01

Applications of porous metallic implants to enhance osseointegration of load-bearing implants are increasing. In this work, porous titanium implants, with 25 volume% porosity, were manufactured using Laser Engineered Net Shaping (LENS™) to measure the influence of porosity towards bone tissue integration in vivo. Surfaces of the LENS™ processed porous Ti implants were further modified with TiO2 nanotubes to improve cytocompatibility of these implants. We hypothesized that interconnected porosity created via additive manufacturing will enhance bone tissue integration in vivo. To test our hypothesis, in vivo experiments using a distal femur model of male Sprague-Dawley rats were performed for a period of 4 and 10 weeks. In vivo samples were characterized via micro-computed tomography (CT), histological imaging, scanning electron microscopy, and mechanical push-out tests. Our results indicate that porosity played an important role to establish early stage osseointegration forming strong interfacial bonding between the porous implants and the surrounding tissue, with or without surface modification, compared to dense Ti implants used as a control. PMID:27307009

Ion implantation and bio-compatibility

Energy Technology Data Exchange (ETDEWEB)

Suzuki, Yoshiaki; Kusakabe, Masahiro [Sony Corp., Tokyo (Japan). Corporate Research Labs.; Iwaki, Masaya

1992-07-01

Surface modification of polymers by ion implantation has been carried out to control surface properties such as conductivity, wettability, blood and tissue compatibility. Ion implantation into silicone rubber, polystyrene and segmented polyurethane was performed at 150 keV with doses ranging from 1 x 10[sup 15] to 3 x 10[sup 17] ions/cm[sup 2] to improve bio-compatibility. The platelet accumulation on ion implanted silicone rubber decreased and non-thrombogenicity of ion implanted specimens were improved. The ion implanted polystyrene and segmented polyurethane have been found to exhibit remarkably higher adhesion and spreading of endothelial cells compared to the non-implanted case. It is concluded that ion implantation into polymers is effective in controlling their bio-compatibility. (author).

Ion Implantation of Calcium and Zinc in Magnesium for Biodegradable Implant Applications

Directory of Open Access Journals (Sweden)

Sahadev Somasundaram

2018-01-01

Full Text Available In this study, magnesium was implanted with calcium-ion and zinc-ion at fluences of 1015, 1016, and 1017 ion·cm−2, and its in vitro degradation behaviour was evaluated using electrochemical techniques in simulated body fluid (SBF. Rutherford backscattering spectrometry (RBS revealed that the implanted ions formed layers within the passive magnesium-oxide/hydroxide layers. Electrochemical impedance spectroscopy (EIS results demonstrated that calcium-ion implantation at a fluence of 1015 ions·cm−2 increased the polarisation resistance by 24%, but higher fluences showed no appreciable improvement. In the case of zinc-ion implantation, increase in the fluence decreased the polarisation resistance. A fluence of 1017 ion·cm−2 decreased the polarisation resistance by 65%, and fluences of 1015 and 1016 showed only marginal effect. Similarly, potentiodynamic polarisation results also suggested that low fluence of calcium-ion decreased the degradation rate by 38% and high fluence of zinc-ion increased the degradation rate by 61%. All the post-polarized ion-implanted samples and the bare metal revealed phosphate and carbonate formation. However, the improved degradative behaviour in calcium-ion implanted samples can be due to a relatively better passivation, whereas the reduction in degradation resistance in zinc-ion implanted samples can be attributed to the micro-galvanic effect.

Biofilm Analysis of Retrieved Dental Implants after Different Peri-Implantitis Treatments

Directory of Open Access Journals (Sweden)

Thaise C. Geremias

2017-01-01

Full Text Available The aim of the current study was to analyse the planktonic growth of Streptococcus mutans on the surfaces of three implants retrieved after three different peri-implantitis treatments. Three implants from a male patient with high levels of bone loss were treated by mechanical debridement, chemical decontamination, and implantoplasty. After 4 months of follow-up, the implants were removed. The growth and biofilm formation were measured by spectrophotometry (OD630 nm and scanning electron microscopy (SEM, after 48 hours of incubation. Results showed an average of Streptococcus mutans planktonic growth over the implants of 0.21 nm (mechanical debridement, 0.16 nm (chemical decontamination, and 0.15 nm (implantoplasty. Data were analysed by ANOVA and Tukey’s test (p<0.05 for chemical decontamination and implantoplasty. Implantoplasty and chemical decontamination showed the lowest levels of planktonic growth, indicating a possible influence of the modification procedures on the titanium surface on the initial biofilm attachment.

Electromagnetic Interference in Patients with Implanted Cardioverter-Defibrillators and Implantable Loop Recorders

Directory of Open Access Journals (Sweden)

Marcos de Sousa

2002-07-01

Full Text Available Modern life exposes us all to an ever-increasing number of potential sources of electromagnetic interference (EMI and patients with Implantable rhythm devices (IRD like pacemakers, implantable cardioverter defibrillators or implantable loop recorders often ask about the use of microwave ovens, walking through airport metal detectors and the use of cellular phones. Electromagnetic interference occurs when electromagnetic waves emitted by one device impede the normal function of another electronic device. The potential for interaction between implanted pacing systems and cardioverter-defibrillators (electromagnetic interference, EMI has been recognized for years.1,2,3,4. It has been shown that EMI can produce clinically significant effects on patients with implanted pacemakers and ICDs. For these reasons the following text discusses the influence of several EMI generating devices on IRD .

Nanotechnology for dental implants.

Science.gov (United States)

Tomsia, Antoni P; Lee, Janice S; Wegst, Ulrike G K; Saiz, Eduardo

2013-01-01

With the advent of nanotechnology, an opportunity exists for the engineering of new dental implant materials. Metallic dental implants have been successfully used for decades, but they have shortcomings related to osseointegration and mechanical properties that do not match those of bone. Absent the development of an entirely new class of materials, faster osseointegration of currently available dental implants can be accomplished by various surface modifications. To date, there is no consensus regarding the preferred method(s) of implant surface modification, and further development will be required before the ideal implant surface can be created, let alone become available for clinical use. Current approaches can generally be categorized into three areas: ceramic coatings, surface functionalization, and patterning on the micro- to nanoscale. The distinctions among these are imprecise, as some or all of these approaches can be combined to improve in vivo implant performance. These surface improvements have resulted in durable implants with a high percentage of success and long-term function. Nanotechnology has provided another set of opportunities for the manipulation of implant surfaces in its capacity to mimic the surface topography formed by extracellular matrix components of natural tissue. The possibilities introduced by nanotechnology now permit the tailoring of implant chemistry and structure with an unprecedented degree of control. For the first time, tools are available that can be used to manipulate the physicochemical environment and monitor key cellular events at the molecular level. These new tools and capabilities will result in faster bone formation, reduced healing time, and rapid recovery to function.

Development of Capital Markets in Turkey and Analysis of Financial Structure of the Intermediary Institutions

Directory of Open Access Journals (Sweden)

Fikret Kartal

2013-08-01

Full Text Available Capital markets, where demand and supply for medium to long term finance meet, are more active and efficient in higher income countries. Capital markets are insufficiently developed in emerging countries such as Turkey that have the structural and institutional obstacles and lack of capital. The first market with securities was established in 19th century in the Ottoman Empire; the Turkish capital markets have gone through the reform programmes as a part of liberalization started in 1980; but the banking sector constitutes the biggest part of the financial sector. The paper presents the development of capital markets in Turkey and analyzes the intermediary institutions by using the financial statements and ratios for the period December 2007-December 2011.

Dental-Implantate und ihre Werkstoffe

Science.gov (United States)

Newesely, Heinrich

1983-07-01

Some new trends in materials for dental implants, which also effect in the operative techniques and implant design, are described. Advantages and shortcomings of the different material types are exemplified and correlated with their bioinert resp. bioactive functions. The practical interest in metallic implants focussed in titanium resp. oxide ceramics in the ceramic field, whereas the special goal of implant research follows from the improvement of the bioactive principle with loaded calcium phosphate implants.

Precipitation processes in implanted materials

International Nuclear Information System (INIS)

Borders, J.A.

1978-01-01

Ion implantation is a nonequilibrium process. It is possible to implant materials with impurities to concentration levels which exceed the solid solubilities. The return of the system to thermodynamic equilibrium is often accomplished by precipitation of the implanted species or a compound involving atoms of both the host and the implanted species. This may involve long time scales when taking place at room temperature or it may take place during the implantation

Develop techniques for ion implantation of PLZT [lead-lanthanum-zirconate-titanate] for adaptive optics

International Nuclear Information System (INIS)

Batishko, C.R.; Brimhall, J.L.; Pawlewicz, W.T.; Stahl, K.A.; Toburen, L.H.

1987-09-01

Research was conducted at Pacific Northwest Laboratory to develop high photosensitivity adaptive optical elements utilizing ion implanted lanthanum-doped lead-zirconate-titanate (PLZT). One centimeter square samples were prepared by implanting ferroelectric and anti-ferroelectric PLZT with a variety of species or combinations of species. These included Ne, O, Ni, Ne/Cr, Ne/Al, Ne/Ni, Ne/O, and Ni/O, at a variety of energies and fluences. An indium-tin oxide (ITO) electrode coating was designed to give a balance of high conductivity and optical transmission at near uv to near ir wavelengths. Samples were characterized for photosensitivity; implanted layer thickness, index of refraction, and density; electrode (ITO) conductivity; and in some cases, residual stress curvature. Thin film anti-ferroelectric PLZT was deposited in a preliminary experiment. The structure was amorphous with x-ray diffraction showing the beginnings of a structure at substrate temperatures of approximately 550 0 C. This report summarizes the research and provides a sampling of the data taken during the report period

Improving the fit of implant prosthetics: an in vitro study.

Science.gov (United States)

Yannikakis, Stavros; Prombonas, Anthony

2013-01-01

Accurate and passive fit between a prosthesis and its supporting implants has been considered a prerequisite for successful long-term osseointegration. The objective of this in vitro study was to evaluate the strain development during tightening of a five-unit screw-retained superstructure constructed using five different methods. Five-unit screw-retained fixed partial prostheses (n = 25) were fabricated on three implants embedded in an epoxy resin block using five different methods: (1) cobalt-chromium (Co-Cr), plastic cylinders, one-piece cast; (2) Co-Cr, plastic cylinders, framework sectioned, preceramic laser-welding soldering; (3) gold-platinum (Au-Pt), gold cylinders, one-piece cast; (4) Au-Pt, gold cylinders, framework sectioned, preceramic laser-welding soldering; (5) Co-Cr, one-piece cast, and cementation to "passive abutments" (Southern Implants) after final finishing and polishing. Strain gauges (SG) were attached to the fixed partial prosthesis (FPP) and to the resin block to measure the stress created during screw tightening. The combination of Co-Cr alloy and plastic cylinders in a one-piece cast showed such an inadequate fit among the fabricated methods that this group was excluded from the remainder of the experiment. Specimens of Au-Pt cast on gold cylinders in one piece showed higher strain development than the other groups used in this study, with strains ranging from 223.1 to 2,198.1 Μm/m. Sectioning and soldering significantly improved the overall fit. FPPs of Co-Cr in a one-piece cast cemented to "passive abutments" produced the best level of fit, with the least strain development in the prosthesis and the resin block (59 to 204.6 Μm/m). Absolute fit of superstructures on implants is not possible using conventional laboratory procedures. Cementing FPPs onto prefabricated cylinders directly onto the implants significantly reduces strain development compared to the other fabrication methods.

Implantable electronic medical devices

CERN Document Server

Fitzpatrick, Dennis

2014-01-01

Implantable Electronic Medical Devices provides a thorough review of the application of implantable devices, illustrating the techniques currently being used together with overviews of the latest commercially available medical devices. This book provides an overview of the design of medical devices and is a reference on existing medical devices. The book groups devices with similar functionality into distinct chapters, looking at the latest design ideas and techniques in each area, including retinal implants, glucose biosensors, cochlear implants, pacemakers, electrical stimulation t

Implant retention systems for implant-retained overdentures.

Science.gov (United States)

Laverty, D P; Green, D; Marrison, D; Addy, L; Thomas, M B M

2017-03-10

Implant retained overdentures are being increasingly utilised in both general and specialist practice to rehabilitate patients with missing teeth, particularly those that are edentate. This article aims to inform the reader of a variety of retention systems that are available to retain an implant overdenture and to understand how these systems work, their advantages and disadvantages and to outline some of the clinical and treatment planning considerations involved in selecting the most appropriate retention system for patients.

Falha prematura em implantes orais = Early oral implant failures

Directory of Open Access Journals (Sweden)

Fadanelli, Alexandro Bianchi

2005-01-01

Full Text Available Atualmente, ainda há uma percentagem significativa de fracassos de implantes na prática clínica, causando transtorno para o profissional e para o paciente. O objetivo deste estudo foi avaliar a bibliografia disponível sobre o assunto, apresentar um caso clínico e discutir os aspectos relacionados aos insucessos na terapia com implantes ocorridos durante o período de osteointegração. A avaliação da literatura mostrou haverem múltiplos fatores possivelmente envolvidos nas falhas de implantes, sendo que através do estudo das falhas pode-se minimizar sua ocorrência

Pre-implantation implantable cardioverter defibrillator concerns and Type D personality increase the risk of mortality in patients with an implantable cardioverter defibrillator

DEFF Research Database (Denmark)

Pedersen, Susanne S.; van den Broek, Krista C; Erdman, Ruud A M

2010-01-01

Little is known about the influence of psychological factors on prognosis in implantable cardioverter defibrillator (ICD) patients. We examined the influence of the distressed personality (Type D) and pre-implantation device concerns on short-term mortality in ICD patients.......Little is known about the influence of psychological factors on prognosis in implantable cardioverter defibrillator (ICD) patients. We examined the influence of the distressed personality (Type D) and pre-implantation device concerns on short-term mortality in ICD patients....

Evidence of increased endometrial vascular permeability at the time of implantation in the short-nosed fruit bat, Cyanopterus sphinx.

Science.gov (United States)

Pakrasi, Pranab Lal; Tiwari, Anjana

2007-09-01

Early embryonic development and implantation were studied in tropical short-nosed fruit bat Cyanopterus sphinx. We report preimplantation development and embryo implantation. Different stages of cleavage were observed in embryo by direct microscopic examination of fresh embryos after retrieving them either from the oviduct or the uterus at different days, up to the day of implantation. Generally, the embryos enter the uterus at the 8-cell stage. Embryonic development continued without any delay and blastocyst were formed showing attachment to the uterine epithelium at the mesometrial side of the uterus. A distinct blue band was formed in the uterus. The site of blastocyst attachment was visualized as a blue band following intravenous injection of pontamine blue. Implantation occurred 9+/-0.7 days after mating. This study reports that bat embryonic development can be studied like other laboratory animals and that this bat shows blue dye reaction, indicating the site and exact time of implantation. This blue dye reaction can be used to accurately find post-implantational delay. We prove conclusively that this species of tropical bat does not have any type of embryonic diapause.

Comparison of surface modified zirconia implants with commercially available zirconium and titanium implants: a histological study in pigs.

Science.gov (United States)

Gredes, Tomasz; Kubasiewicz-Ross, Pawel; Gedrange, Tomasz; Dominiak, Marzena; Kunert-Keil, Christiane

2014-08-01

New biomaterials and their various surface modifications should undergo in vitro and in vivo evaluation before clinical trials. The objective of our in vivo study was to evaluate the biocompatibility of newly created zirconium implant surfaces after implantation in the lower jaw of pigs and compare the osseointegration of these dental implants with commercially available zirconium and titanium implants. After a healing period of 12 weeks, a histological analysis of the soft and hard tissues and a histomorphometric analysis of the bone-implant contact (BIC) were performed. The implant surfaces showed an intimate connection to the adjacent bone for all tested implants. The 3 newly created zirconium implant surfaces achieved a BIC of 45% on average in comparison with a BIC of 56% from the reference zirconium implants and 35% from titanium implants. Furthermore, the new zirconium implants had a better attachment to gingival and bone tissues in the range of implant necks as compared with the reference implants. The results suggest that the new implants comparably osseointegrate within the healing period, and they have a good in vivo biocompatibility.

Evaluation of contiguous implants with cement-retained implant-abutment connections. A minipig study

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Raquel Rezende Martins de Barros

2014-03-01

Full Text Available Aim: The presence of a microgap at the implant-abutment interface may permit bacterial contamination and lead to bone resorption, interfering with papillae formation. The present study evaluated adjacent implants with cement-retained abutments as an option to control such deleterious effects. Materials and methods Seven minipigs had their bilateral mandibular premolars previously extracted. After 8 weeks, four implants were installed in each hemi-mandible of each animal. The adjacent implants were randomly inserted on one side at the crestal bone level and on the other, 1.5 mm subcrestally. Immediately, a non-submerged healing and functional loading were provided with the abutments cementation and prostheses installation. Clinical examination and histomorphometry served to analyze the implant success. Results A total of 52 implants were evaluated at the end of the study. The subcrestal group achieved statistical better results when compared to the crestal group, clinically in papillae formation (1.97 x 1.57 mm and histomorphometrically in crestal bone remodeling (1.17 x 1.63 mm, bone density (52.39 x 45.22% and bone-implant contact (54.13 x 42.46%. Conclusion The subcrestal placement of cement-retained abutment implants showed better indexes of osseointegration and also improved papillae formation and crestal bone remodeling at the interimplant area after immediate loading, making them a promising option for the treatment of esthetic regions.

The effect of varying implant position in immediately loaded implant-supported mandibular overdentures.

Science.gov (United States)

Shaarawy, Mohammed A; Aboelross, Ehab M

2013-06-01

This study was carried out to evaluate the effect of varying implant position in immediately loaded implant-supported mandibular overdentures on peri-implant bone density, muscle activity, and patient satisfaction. Fourteen completely edentulous patients were selected for the study. After complete denture construction, patients were divided into 2 equal groups. Four dental implants were installed bilaterally in the interforaminal region in the first group, while in the second group, 4 dental implants were inserted bilaterally: 2 in the interforaminal region and 2 in the first molar area. Immediately after suturing, telescopic abutments were screwed to the implants, and the retaining caps were picked up into the fitting surface of the lower denture, which was delivered to the patient. Patients were recalled for radiographic bone density evaluation just after denture delivery and then at 3, 6, and 12 months thereafter. Muscle activities of masseter and temporalis muscles as well as patient satisfaction were also evaluated. The results of the study showed a high success rate approximating 98.2% of the immediately loaded implants. The electromyographic (EMG) records of both muscles in group 1 were significantly higher during chewing hard food after 3 months compared with group 2 (P overdentures through posterior placement beyond the interforaminal area results in a favorable response in terms of increased peri-implant bone density as well as decreased EMG activity of masseter and temporalis muscles.

Inductive Contactless Distance Measurement Intended for a Gastric Electrical Implant

Directory of Open Access Journals (Sweden)

J. Tomek

2007-01-01

Full Text Available For a gastric electrical stimulation project we are developing a system for on-demand switching according to the volume or elongation of the stomach wall. The system is to be implanted into the human abdomen, which limits the utilization of many possible solutions and types of sensors. Magnetic induction has been agreed as the most suitable principle, despite its direction dependency and the need of multi-axial and multiple probes for precision measurements. Possible configurations are discussed as well as the complexity of the necessary electronics and the implantation itself. For detecting food consumption, perfect precision is fortunately not necessary, but a certain compromise will still be necessary for the final system. A simple two-coil system – a transmitter and receiver and a system with a three-axial coil – have already been realized. The first system has already been successfully tested in-vivo on dogs by our US colleagues. However, if the implantation is badly performed, and the coils are completely out of axis, the system cannot sense relative changes in volume properly. The three-axial sensor presented here eliminates these problems. More complex arrangements emerging from magnetic tracking are discussed, because laboratory studies of stomach movements may require them. 

Diagnostic Principles of Peri-Implantitis: a Systematic Review and Guidelines for Peri-Implantitis Diagnosis Proposal

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Ausra Ramanauskaite

2016-09-01

Full Text Available Objectives: To review and summarize the literature concerning peri-implantitis diagnostic parameters and to propose guidelines for peri-implantitis diagnosis. Material and Methods: An electronic literature search was conducted of the MEDLINE (Ovid and EMBASE databases for articles published between 2011 and 2016. Sequential screening at the title/abstract and full-text levels was performed. Systematic reviews/guidelines of consensus conferences proposing classification or suggesting diagnostic parameters for peri-implantitis in the English language were included. The review was recorded on PROSPERO system with the code CRD42016033287. Results: The search resulted in 10 articles that met the inclusion criteria. Four were papers from consensus conferences, two recommended diagnostic guidelines, three proposed classification of peri-implantitis, and one suggested an index for implant success. The following parameters were suggested to be used for peri-implantitis diagnosis: pain, mobility, bleeding on probing, probing depth, suppuration/exudate, and radiographic bone loss. In all of the papers, different definitions of peri-implantitis or implant success, as well as different thresholds for the above mentioned clinical and radiographical parameters, were used. Current evidence rationale for the diagnosis of peri-implantitis and classification based on consecutive evaluation of soft-tissue conditions and the amount of bone loss were suggested. Conclusions: Currently there is no single uniform definition of peri-implantitis or the parameters that should be used. Rationale for diagnosis and prognosis of peri-implantitis as well as classification of the disease is proposed.

Surface characterization of titanium based dental implants; Caracterizacao de implantes odontologicos a base de titanio

Energy Technology Data Exchange (ETDEWEB)

Castilho, Guilherme Augusto Alcaraz

2006-07-01

Dental implantology uses metallic devices made of commercially pure titanium in order to replace lost teeth. Titanium presents favorable characteristics as bio material and modern implants are capable of integrate, witch is the union between bone and implant without fibrous tissue development. Three of the major Brazilian implant manufacturers were chosen to join the study. A foreign manufacturer participated as standard. The manufacturers had three specimens of each implant with two different surface finishing, as machined and porous, submitted to analysis. Surface chemical composition and implant morphology were analyzed by X-ray photoelectron spectroscopy (XP S), scanning electron microscopy (SEM) and microprobe. Implant surface is mainly composed of titanium, oxygen and carbon. Few contaminants commonly present on implant surface were found on samples. Superficial oxide layer is basically composed of titanium dioxide (TiO{sub 2}), another oxides as Ti O and Ti{sub 2}O{sub 3} were also found in small amount. Carbon on implant surface was attributed to manufacturing process. Nitrogen, Phosphorous and Silicon appeared in smaller concentration on surface. There was no surface discrepancy among foreign and Brazilian made implants. SEM images were made on different magnification, 35 X to 3500 X, and showed similarity among as machined implants. Porous surface finishing implants presented distinct morphology. This result was attributed to differences on manufacturing process. Implant bioactivity was accessed through immersion on simulated body solution (SBF) in order to verify formation of an hydroxyapatite (HA) layer on surface. Samples were divided on three groups according to immersion time: G1 (7 days), G2 (14 days), G3 (21 days), and deep in SBF solution at 37 deg C. After being removed from solution, XPS analyses were made and then implants have been submitted to microprobe analysis. XPS showed some components of SBF solution on sample surface but microprobe

Influence of Palatal Coverage and Implant Distribution on Denture Strain in Maxillary Implant Overdentures.

Science.gov (United States)

Takahashi, Toshihito; Gonda, Tomoya; Tomita, Akiko; Mizuno, Yoko; Maeda, Yoshinobu

2016-01-01

As maxillary implant overdentures are being increasingly used in clinical practice, prosthodontic complications related to these dentures are also reported more often. The purpose of this study was to examine the influence of palatal coverage and implant distribution on the shear strain of maxillary implant overdentures. A maxillary edentulous model with implants inserted in the anterior, premolar, and molar areas was fabricated. Two kinds of experimental overdentures, with and without palatal coverage, were also fabricated, and two strain gauges were attached at the midline of the labial and palatal sides. A vertical occlusal load of 98 N was applied through a mandibular complete denture, and the shear strain in each denture was compared by analysis of variance (P = .05). In all situations, the shear strain in palateless dentures was significantly higher than in dentures with palate on both sides (P overdentures exhibited much higher strain than overdentures with palate regardless of the implant distribution; this may cause more prosthodontic and implant complications. The most favorable configuration to prevent complications in maxillary implant overdentures was palatal coverage that was supported by more than four widely distributed implants.

Simulation and visualization of ion-implantation in diamond

International Nuclear Information System (INIS)

Adler, Joan; Silverman, Amihai; Ierushalmi, Niv; Sorkin, Anastassia; Kalish, Rafi

2014-01-01

We have explored aspects of ion implantation in diamonds with molecular dynamics and tightbinding atomistic simulations. Relevant experiments and their potential applications as well as our computer models and computational approaches are described. Our simulations have been designed to answer questions proposed by experimental researchers concerning optimal laboratory schedules for the preparation of samples with potential applications to diamond membranes and NV centers for quantum computers. Simulation and visualization of results enable us to peek inside samples where experimental techniques cannot tread. In order to provide the requisite Brazilian component a new connection between these models and bootstrap percolation is made

Implantation, recoil implantation, and sputtering

International Nuclear Information System (INIS)

Kelly, R.

1984-01-01

Underlying ion-beam modification of surfaces is the more basic subject of particle-surface interaction. The ideas can be grouped into forward and backward features, i.e. those affecting the interior of the target and those leading to particle expulsion. Forward effects include the stopping of the incident particles and the deposition of energy, both governed by integral equations which are easily set up but difficult to solve. Closely related is recoil implantation where emphasis is placed not on the stopping of the incident particles but on their interaction with target atoms with resulting implantation of these atoms. Backward effects, all of which are denoted as sputtering, are in general either of collisional, thermal, electronic, or exfoliational origin. (Auth.)

Impact of dental implant insertion method on the peri-implant bone tissue: Experimental study

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Stamatović Novak

2013-01-01

Full Text Available Background/Aim. The function of dental implants depends on their stability in bone tissue over extended period of time, i.e. on osseointegration. The process through which osseointegration is achieved depends on several factors, surgical insertion method being one of them. The aim of this study was to histopathologically compare the impact of the surgical method of implant insertion on the peri-implant bone tissue. Methods. The experiment was performed on 9 dogs. Eight weeks following the extraction of lower premolars implants were inserted using the one-stage method on the right mandibular side and two-stage method on the left side. Three months after implantation the animals were sacrificed. Three distinct regions of bone tissue were histopathologically analyzed, the results were scored and compared. Results. In the specimens of one-stage implants increased amount of collagen fibers was found in 5 specimens where tissue necrosis was also observed. Only moderate osteoblastic activity was found in 3 sections. The analysis of bone-to-implant contact region revealed statistically significantly better results regarding the amount of collagen tissue fibers for the implants inserted in the two-stage method (Wa = 59 105, α = 0.05. No necrosis and osteoblastic activity were observed. Conclusion. Better results were achieved by the two-stage method in bone-to-implant contact region regarding the amount of collagen tissue, while the results were identical regarding the osteoblastic activity and bone tissue necrosis. There was no difference between the methods in the bone-implant interface region. In the bone tissue adjacent to the implant the results were identical regarding the amount of collagen tissue, osteoblastic reaction and bone tissue necrosis, while better results were achieved by the two-stage method regarding the number of osteocytes.

Bone-Implant Contact around Crestal and Subcrestal Dental Implants Submitted to Immediate and Conventional Loading

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Ana Emília Farias Pontes

2014-01-01

Full Text Available The present study aims to evaluate the influence of apicocoronal position and immediate and conventional loading in the percentage of bone-implant contact (BIC. Thus, 36 implants were inserted in the edentulous mandible from six dogs. Three implants were installed in each hemimandible, in different positions in relation to the ridge: Bone Level (at crestal bone level, Minus 1 (one millimeter apical to crestal bone, and Minus 2 (two millimeters apical to crestal bone. In addition, each hemimandible was submitted to a loading protocol: immediate (prosthesis installed 24 hours after implantation or conventional (prosthesis installed 120 days after implantation. Ninety days after, animals were killed, and implant and adjacent tissues were prepared for histometric analysis. BIC values from immediate loaded implants were 58.7%, 57.7%, and 51.1%, respectively, while conventional loaded implants were 61.8%, 53.8%, and 68.4%. Differences statistically significant were not observed among groups (P=0.10, ANOVA test. These findings suggest that different apicocoronal positioning and loading protocols evaluated did not interfere in the percentage of bone-implant contact, suggesting that these procedures did not jeopardize osseointegration.

Inborn Errors of Intermediary Metabolism in Critically Ill Mexican Newborns

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Ibarra-González Isabel MSc

2014-04-01

Full Text Available Inborn errors of intermediary metabolism (IEiM are complex diseases with high clinical heterogeneity, and some patients who have severe enzyme deficiencies or are subjected to stress (catabolism/infections actually decompensate in the neonatal period. In this study, we performed metabolic tests on 2025 newborns in Mexico admitted to 35 neonatal intensive care units or emergency wards (NICUs/EWs over a 6-year period, in whom a metabolic disorder was clinically suspected. Of these 2025 newborns with sickness, 11 had IEiM, revealing a prevalence of 1:184. Clinical characteristics and outcomes of the newborns with confirmed IEiM are shown. Of these 11 patients, 4 had isolated methylmalonic acidemia, 3 had maple syrup urine disease, 2 had urea cycle disorders, 1 had 3-hydroxy-3-methylglutaric acidemia, and 1 had isovaleric acidemia. During the first week of life (average 3 days, all of these newborns presented with impaired alertness, hypotonia, feeding difficulties, and vomiting along with metabolic acidosis and hyperammonemia. Of the 11 newborns with IEiM, 7 died, leading to a mortality rate of 64%. In conclusion, the differential diagnosis of newborns admitted to the NICU/EW must include IEiM, requiring systematic screening of this population.

Successful Rehabilitation of Partial Edentulous Maxilla and Mandible with New Type of Implants: Molecular Precision Implants

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Matteo Danza

2014-01-01

Full Text Available The extraction of teeth results in rapid bone resorption both vertically and horizontally in the first month. The loss of alveolar ridge reduces the chance of implant rehabilitation. Atraumatic extraction, implant placement in extraction socket, and an immediate prosthesis have been proposed as alternative therapies to maintain the volume and contours tissue and reduce time and cost of treatment. The immediate load of implants is a universally practiced procedure; nevertheless a successful procedure requires expertise in both the clinical and the reconstructive stages using a solid implant system. Excellent primary stability and high bone-implant contact are only minimal requirements for any type of implant procedure. In this paper we present a case report using a new type of implants. The new type of implants, due to its sophisticated control system of production, provides to the implantologist a safe and reliable implant, with a macromorphology designed to ensure a close contact with the surrounding bone.

Radioactive implants for medical applications; Radioaktive Implantate fuer medizinische Anwendungen

Energy Technology Data Exchange (ETDEWEB)

Schubert, M.

2008-07-01

The long-term success of surgery is often diminished by excessive wound healing, which makes another intervention necessary. Locally applied radionuclides with short range radiation can prevent such benign hyperproliferation. As pure electron emitter with a half-life of 14.3 days and a mean energy of 694.9 keV (E{sub max}=1710.48 keV) {sup 32}P is a suitable radionuclide which can be produced from the stable {sup 31}P by the capture of thermal neutrons (1 x 10{sup 14} /s/cm{sup 2}) in a nuclear reactor. After a typical irradiation time (14 days) the ratio of {sup 32}P to {sup 31}P is 1.4 x 10{sup -5} to 1. Implants made of polymer and/or bioabsorbable material functioning as a carrier of the radioactive emitter allow - as opposed to metallic implants - for new applications for this type of radiotherapy. In this thesis a manufacturing method for previously not available organic, radioactive implants has been developed and a corresponding dosimetry system has been established. By means of ion implantation, {sup 32}P ions with up to 180 keV can be shot some 100 nm deep into organic implant materials. For a typical dose (15 Gy over 7 days, 1 mm distance from the implant) an activity of 75 kBq is needed corresponding to 1.3 x 10{sup 11} {sup 32}P ions. The sputter ion gun, which has been optimized for this application, creates an ion beam with high beam current (> 14 {mu}A P{sup -}) and low emittance (< 4 {pi} mm mrad {radical}(MeV)). Because of the good beam quality also small implants (<1 mm{sup 2}) can be manufactured with high efficiency. The unintentionally co-implanted portion of molecules and nuclides of the same mass (e.g. {sup 31}PH, {sup 16}O{sub 2} and {sup 32}S) could be reduced from approximately 500 to 50 by an improvement of the isotope selection at {sup 32}P beam creation. Hence, in comparison with the best hitherto existing implantation methods, the radiation dose of the implant could be reduced by an order of magnitude. With regard to the beta

Reliability of implant placement with stereolithographic surgical guides generated from computed tomography: clinical data from 94 implants.

Science.gov (United States)

Ersoy, Ahmet Ersan; Turkyilmaz, Ilser; Ozan, Oguz; McGlumphy, Edwin A

2008-08-01

Dental implant placement requires precise planning with regard to anatomic limitations and restorative goals. The aim of this study was to evaluate the match between the positions and axes of the planned and placed implants using stereolithographic (SLA) surgical guides. Ninety-four implants were placed using SLA surgical guides generated from computed tomography (CT) between 2005 and 2006. Radiographic templates were used for all subjects during CT imaging. After obtaining three-dimensional CT images, each implant was virtually placed on the CT images. SLA surgical guides, fabricated using an SLA machine with a laser beam to polymerize the liquid photo-polymerized resin, were used during implant placement. A new CT scan was taken for each subject following implant placement. Special software was used to fuse the images of the planned and placed implants, and the locations and axes were compared. Compared to the planned implants, the placed implants showed angular deviation of 4.9 degrees+/-2.36 degrees, whereas the mean linear deviation was 1.22+/-0.85 mm at the implant neck and 1.51+/-1 mm at the implant apex. Compared to the implant planning, the angular deviation and linear deviation at the neck and apex of the placed maxillary implants were 5.31 degrees+/-0.36 degrees, 1.04+/-0.56 mm, and 1.57+/-0.97 mm, respectively, whereas corresponding figures for placed mandibular implants were 4.44 degrees+/-0.31 degrees, 1.42+/-1.05 mm, and 1.44+/-1.03 mm, respectively. SLA surgical guides using CT data may be reliable in implant placement and make flapless implant placement possible.

Miniscrew implant applications in contemporary orthodontics

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Hong-Po Chang

2014-03-01

Full Text Available The need for orthodontic treatment modalities that provide maximal anchorage control but with minimal patient compliance requirements has led to the development of implant-assisted orthodontics and dentofacial orthopedics. Skeletal anchorage with miniscrew implants has no patient compliance requirements and has been widely incorporated in orthodontic practice. Miniscrew implants are now routinely used as anchorage devices in orthodontic treatment. This review summarizes recent data regarding the interpretation of bone data (i.e., bone quantity and quality obtained by preoperative diagnostic computed tomography (CT or by cone-beam computed tomography (CBCT prior to miniscrew implant placement. Such data are essential when selecting appropriate sites for miniscrew implant placement. Bone characteristics that are indications and contraindications for treatment with miniscrew implants are discussed. Additionally, bicortical orthodontic skeletal anchorage, risks associated with miniscrew implant failure, and miniscrew implants for nonsurgical correction of occlusal cant or vertical excess are reviewed. Finally, implant stability is compared between titanium alloy and stainless steel miniscrew implants.

Control of a Two-Stage Direct Power Converter with a Single Voltage Sensor Mounted in the Intermediary Circuit

DEFF Research Database (Denmark)

Klumpner, Christian; Wheeler, P.; Blaabjerg, Frede

2004-01-01

Controlling a converter requires not only a powerful processors but also accurate voltage and current sensors and fast and precise analogue-digital converters, which increase the cost per kW of the assembly, especially in the low power range. A matrix converter requires less transducers than a back...... converters but in two stages (AC/DC/AC) without using energy storage in the intermediary circuit. They also offer the possibility to reduce the number of switches compared to the standard single-stage matrix converter. This paper presents a new method to control a two-stage DPC providing sine-wave in sine...

Ion implantation for semiconductors

International Nuclear Information System (INIS)

Grey-Morgan, T.

1995-01-01

Full text: Over the past two decades, thousands of particle accelerators have been used to implant foreign atoms like boron, phosphorus and arsenic into silicon crystal wafers to produce special embedded layers for manufacturing semiconductor devices. Depending on the device required, the atomic species, the depth of implant and doping levels are the main parameters for the implantation process; the selection and parameter control is totally automated. The depth of the implant, usually less than 1 micron, is determined by the ion energy, which can be varied between 2 and 600 keV. The ion beam is extracted from a Freeman or Bernas type ion source and accelerated to 60 keV before mass analysis. For higher beam energies postacceleration is applied up to 200 keV and even higher energies can be achieved by mass selecting multiplycharged ions, but with a corresponding reduction in beam output. Depending on the device to be manufactured, doping levels can range from 10 10 to 10 15 atoms/cm 2 and are controlled by implanter beam currents in the range up to 30mA; continuous process monitoring ensures uniformity across the wafer of better than 1 % . As semiconductor devices get smaller, additional sophistication is required in the design of the implanter. The silicon wafers charge electrically during implantation and this charge must be dissipated continuously to reduce the electrical stress in the device and avoid destructive electrical breakdown. Electron flood guns produce low energy electrons (below 10 electronvolts) to neutralize positive charge buildup and implanter design must ensure minimum contamination by other isotopic species and ensure low internal sputter rates. The pace of technology in the semiconductor industry is such that implanters are being built now for 256 Megabit circuits but which are only likely to be widely available five years from now. Several specialist companies manufacture implanter systems, each costing around US$5 million, depending on the

Operation of low-energy ion implanters for Si, N, C ion implantation into silicon and glassy carbon

International Nuclear Information System (INIS)

Carder, D.A.; Markwitz, A.

2009-01-01

This report details the operation of the low-energy ion implanters at GNS Science for C, N and Si implantations. Two implanters are presented, from a description of the components through to instructions for operation. Historically the implanters have been identified with the labels 'industrial' and 'experimental'. However, the machines only differ significantly in the species of ions available for implantation and sample temperature during implantation. Both machines have been custom designed for research purposes, with a wide range of ion species available for ion implantation and the ability to implant two ions into the same sample at the same time from two different ion sources. A fast sample transfer capability and homogenous scanning profiles are featured in both cases. Samples up to 13 mm 2 can be implanted, with the ability to implant at temperatures down to liquid nitrogen temperatures. The implanters have been used to implant 28 Si + , 14 N + and 12 C + into silicon and glassy carbon substrates. Rutherford backscattering spectroscopy has been used to analyse the implanted material. From the data a Si 30 C 61 N 9 layer was measured extending from the surface to a depth of about 77 ± 2 nm for (100) silicon implanted with 12 C + and 14 N + at multiple energies. Silicon and nitrogen ion implantation into glassy carbon produced a Si (40.5 %), C (38 %), N (19.5 %) and O (2%) layer centred around a depth of 50 ± 2 nm from the surface. (author). 8 refs., 20 figs

High energy ion implantation

International Nuclear Information System (INIS)

Ziegler, J.F.

1985-01-01

High energy ion implantation offers the oppertunity for unique structures in semiconductor processing. The unusual physical properties of such implantations are discussed as well as the special problems in masking and damage annealing. A review is made of proposed circuit structures which involve deep implantation. Examples are: deep buried bipolar collectors fabricated without epitaxy, barrier layers to reduce FET memory sensitivity to soft-fails, CMOS isolation well structures, MeV implantation for customization and correction of completed circuits, and graded reach-throughs to deep active device components. (orig.)

Cochlear implant magnet retrofit.

Science.gov (United States)

Cohen, N L; Breda, S D; Hoffman, R A

1988-06-01

An implantable magnet is now available for patients who have received the standard Nucleus 22-channel cochlear implant and who are not able to wear the headband satisfactorily. This magnet is attached in piggy-back fashion to the previously implanted receiver/stimulator by means of a brief operation under local anesthesia. Two patients have received this magnet retrofit, and are now wearing the headset with greater comfort and satisfaction. It is felt that the availability of this magnet will increase patient compliance in regard to hours of implant usage.

Implant-retained maxillary overdentures.

Science.gov (United States)

Eckert, Steven E; Carr, Alan B

2004-07-01

Overdentures supported by osseointegrated implants overcome many of the complications observed with overdentures supported by natural teeth. Dental implants are free of biologic consequences associated with natural teeth, such as dental caries and periodontal disease. Bone undercuts adjacent to implants do not mimic those found adjacent to natural tooth roots. Implants are used to provide predictable retention, support, and stability for overdenture prostheses. When lip or facial support is required, the overdenture is the treatment of choice. Likewise the overdenture may improve phonetic deficiencies associated with alveolar bone loss.

The diffusion properties of ion implanted species in selected target materials

International Nuclear Information System (INIS)

Alton, G.D.; Dellwo, J.; Carter, H.K.; Kormicki, J.; Bartolo, G. di; Batchelder, J.C.; Breitenbach, J.; Chediak, J.A.; Jentoff-Nilsen, K.; Ichikawa, S.

1995-01-01

Experiments important to the future success of the Holifield Radioactive Ion Beam Facility (HRIBF) are in progress at the Oak Ridge National Laboratory which are designed to select the most appropriate target material for generating a particular radioactive ion beam (RIB). The 25-MV HHIRF tandem accelerator is used to implant stable complements of interesting radioactive elements into refractory targets mounted in a high-temperature FEBIAD ion source which is open-quotes on-lineclose quotes at the UNISOR facility. The intensity versus time of implanted species, which diffuse from the high-temperature target material (∼1700 degrees C) and are ionized in the FEBIAD ion source, is used to determine release times for a particular projectile/target material combination. From such release data, diffusion coefficients can be derived by fitting the theoretical results obtained by computational solution of Fick's second equation to experimental data. The diffusion coefficient can be used subsequently to predict the release properties of the particular element from the same material in other target geometries and at other temperatures, provided that the activation energy is also known. Diffusion coefficients for Cl implanted into and diffused from CeS and Zr 5 Si 3 and As, Br, and Se implanted into and diffused from Zr 5 Ge 3 have been derived from the resulting intensity versus time profiles. Brief descriptions of the experimental apparatus and procedures utilized in the present experiments and plans for future related experiments are presented

High attrition among HIV-infected patients with advanced disease treated in an intermediary referral center in Maputo, Mozambique

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Lucas Molfino

2014-04-01

Full Text Available Background: In Mozambique, antiretroviral therapy (ART scale-up has been successfully implemented. However, attrition in care remains a major programmatic challenge. In 2009, an intermediary-level HIV referral center was created in Maputo to ensure access to specialized care for HIV-infected patients with complications (advanced clinical-immunological stage, Kaposi sarcoma, or suspected ART failure. Objective: To determine the attrition from care and to identify risk factors that lead to high attrition among patients referred to an intermediary-level HIV referral center. Design: This was a retrospective cohort study from 2009 to 2011. Results: A total of 1,657 patients were enrolled, 847 (51% were men, the mean age was 36 years (standard deviation: 11, the mean CD4 count was 27 cells/µl (interquartile range: 11–44, and one-third were severely malnourished. The main reasons for referral were advanced clinical stages (WHO stages 3 and 4, and CD4 count <50 cells/µl in 70% of the cases, and 19% had Kaposi sarcoma. The overall attrition rate was 28.7 per 100 person-years (PYs – the mortality rate was 5.0 (95% confidence interval [CI]: 4.2–5.9 per 100 PYs, and the loss-to-follow-up rate was 23.7 (95% CI: 21.9–25.6 per 100 PYs. There were 793 attritions – 137 deaths and 656 lost to follow-up (LTFU; 77% of all attrition happened within the first year. The factors independently associated with attrition were male sex (adjusted hazard ratio [aHR]: 1.15, 95% CI: 1.0–1.3, low body mass index (aHR: 1.51, 95% CI: 1.2–1.8, WHO clinical stage 3 or 4 (aHR: 1.30, 95% CI: 1.0–1.6; and aHR: 1.91, 95% CI: 1.4–2.5, later year of enrollment (aHR 1.61, 95% CI 1.3–1.9, and ‘being already on ART’ at enrollment (aHR 13.71, 95% CI 11.4–16.4. Conclusions: Attrition rates among HIV-infected patients enrolled in an intermediary referral center were high, mainly related to advanced stage of clinical disease. Measures are required to address this

Cone-morse implant connection system significantly reduces bacterial leakage between implant and abutment: an in vitro study.

Science.gov (United States)

Baj, A; Bolzoni, A; Russillo, A; Lauritano, D; Palmieri, A; Cura, F; Silvestre, F J; Giannì, A B

2017-01-01

Osseointegrated implants are very popular dental treatments today in the world. In osseointegrated implants, the occlusal forces are transmitted from prosthesis through an abutment to a dental implant. The abutment is connected to the implant by mean of a screw. A screw is the most used mean for connecting an implant to an abutment. Frequently the screws break and are lost. There is an alternative to screw retained abutment systems: the cone-morse connection (CMC). The CMC, thanks to the absence of the abutment screw, guarantees no micro-gaps, no micro-movements, and a reduction of bacterial leakage between implant and abutment. As P. gingivalis and T. forsythia penetration might have clinical relevance, it was the purpose of this investigation to evaluate molecular leakage of these two bacteria in a new CMC implants systems (Leone Spa®, Florence, Italy). To identify the capability of the implant to protect the internal space from the external environment, the passage of genetically modified Escherichia coli across implant-abutment interface was evaluated. Four cone-morse Leone implants (Leone® Spa, Florence, Italy) were immerged in a bacterial culture for 24 h and bacteria amount was then measured inside implant-abutment interface with Real-time PCR. Bacteria were detected inside all studied implants, with a median percentage of 3% for P. gingivalis and 4% for T. forsythia. Cone-morse connection implant system has very low bacterial leakage percentage and is similar to one-piece implants.

First implantation of selective his bundle pacing in Colombia. Report of two cases

International Nuclear Information System (INIS)

Velasquez, Jorge E; Duque, Mauricio; Marin V, Jorge E; Aristizabal, Julian M; Medina, Luis E; Gonzalez, Edgardo; Duque, Laura; Uribe, William

2010-01-01

Pacing in the right ventricular apex is known to produce ventricular dysynchrony and patients often develop dilated cardiomyopathy. For this reason, a more physiological stimulation has been performed. With the recent technological development of electrodes for selective stimulation of the His bundle, we want to show the experience of this type of implantation in the first two cases made in the electrophysiology laboratory in Medellin.

Production of Endohedral Fullerenes by Ion Implantation

Energy Technology Data Exchange (ETDEWEB)

Diener, M.D.; Alford, J. M.; Mirzadeh, S.

2007-05-31

The empty interior cavity of fullerenes has long been touted for containment of radionuclides during in vivo transport, during radioimmunotherapy (RIT) and radioimaging for example. As the chemistry required to open a hole in fullerene is complex and exceedingly unlikely to occur in vivo, and conformational stability of the fullerene cage is absolute, atoms trapped within fullerenes can only be released during extremely energetic events. Encapsulating radionuclides in fullerenes could therefore potentially eliminate undesired toxicity resulting from leakage and catabolism of radionuclides administered with other techniques. At the start of this project however, methods for production of transition metal and p-electron metal endohedral fullerenes were completely unknown, and only one method for production of endohedral radiofullerenes was known. They therefore investigated three different methods for the production of therapeutically useful endohedral metallofullerenes: (1) implantation of ions using the high intensity ion beam at the Oak Ridge National Laboratory (ORNL) Surface Modification and Characterization Research Center (SMAC) and fullerenes as the target; (2) implantation of ions using the recoil energy following alpha decay; and (3) implantation of ions using the recoil energy following neutron capture, using ORNL's High Flux Isotope Reactor (HFIR) as a thermal neutron source. While they were unable to obtain evidence of successful implantation using the ion beam at SMAC, recoil following alpha decay and neutron capture were both found to be economically viable methods for the production of therapeutically useful radiofullerenes. In this report, the procedures for preparing fullerenes containing the isotopes {sup 212}Pb, {sup 212}Bi, {sup 213}Bi, and {sup 177}Lu are described. None of these endohedral fullerenes had ever previously been prepared, and all of these radioisotopes are actively under investigation for RIT. Additionally, the chemistry for

One-year results of maxillary overdentures supported by 2 titanium-zirconium implants - implant survival rates and radiographic outcomes.

Science.gov (United States)

Zembic, Anja; Tahmaseb, Ali; Jung, Ronald E; Wismeijer, Daniel

2017-07-01

To assess implant survival rates and peri-implant bone loss of 2 titanium-zirconium implants supporting maxillary overdentures at 1 year of loading. Twenty maxillary edentulous patients (5 women and 15 men) being dissatisfied with their complete dentures were included. In total, 40 diameter-reduced titanium-zirconium implants were placed in the anterior maxilla. Local guided bone regeneration (GBR) was allowed if the treatment did not compromise implant stability. Following 3 to 5 months of healing, implant-supported overdentures were inserted on two ball anchors. Implants and overdentures were assessed at 1, 2, 4, and 8 weeks after implant insertion and 2, 4, and 12 months after insertion of overdentures (baseline). Standardized radiographs were taken at implant loading and 1 year. Implant survival rates and bone loss were the primary outcomes. Nineteen patients (1 dropout) with 38 implants were evaluated at a mean follow-up of 1.1 years (range 1.0-1.7 years). One implant failed resulting in an implant survival rate of 97.3%. There was a significant peri-implant bone loss of the implants at 1 year of function (mean, 0.7 mm, SD = 1.1 mm; median: 0.48 mm, IQR = 0.56 mm). There was a high 1-year implant survival rate for edentulous patients receiving 2 maxillary implants and ball anchors as overdenture support. However, several implants exhibited an increased amount of bone loss of more than 2 mm. Overdentures supported by 2 maxillary implants should thus be used with caution as minimally invasive treatment for specific patients encountering problems with their upper dentures until more long-term data is available. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Surgical management of fibrotic encapsulation of the fluocinolone acetonide implant in CAPN5-associated proliferative vitreoretinopathy

Directory of Open Access Journals (Sweden)

Tlucek PS

2013-06-01

Full Text Available Paul S Tlucek,1 James C Folk,1 Warren M Sobol,2 Vinit B Mahajan1,3 1Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, USA; 2Retina Physicians and Surgeons, Dayton, OH, USA; 3Omics Laboratory, University of Iowa, Iowa City, IA, USA Objective: To review fibrosis of fluocinolone acetonide (FA implants in subjects with CAPN5 autosomal dominant neovascular inflammatory vitreoretinopathy (ADNIV. Methods: A retrospective case series was assembled from ADNIV patients in which there was fibrotic encapsulation of a fluocinolone acetonide implant. CAPN5 genotypes and surgical repair techniques were reviewed. Results: Two eyes of two ADNIV patients developed a fibrotic capsule over the fluocinolone acetonide implant. Both patients had Stage IV disease. Patient A had a c.731T > C mutation in the CAPN5 gene and patient B had a c.728G > T mutation. The fibrotic membrane was surgically excised and the implant function was restored. Conclusion: The exuberant fibrotic response in later stages of ADNIV may be resistant to local immunosuppression with steroids. Surgical excision of fibrotic membranes over FA implants can reestablish local steroid delivery in cases of severe proliferative vitreoretinopathy. Keywords: autosomal dominant neovascular inflammatory vitreoretinopathy, ADNIV, CAPN5, calpain-5, Retisert, fluocinolone acetonide, fibrotic encapsulation

Implantable Medical Devices

Science.gov (United States)

... Artery Disease Venous Thromboembolism Aortic Aneurysm More Implantable Medical Devices Updated:Sep 16,2016 For Rhythm Control ... a Heart Attack Introduction Medications Surgical Procedures Implantable Medical Devices • Life After a Heart Attack • Heart Attack ...

Finite Element Analysis of Bone Stress for Miniscrew Implant Proximal to Root Under Occlusal Force and Implant Loading.

Science.gov (United States)

Shan, Li-Hua; Guo, Na; Zhou, Guan-jun; Qie, Hui; Li, Chen-Xi; Lu, Lin

2015-10-01

Because of the narrow interradicular spaces and varying oral anatomies of individual patients, there is a very high risk of root proximity during the mini implants inserting. The authors hypothesized that normal occlusal loading and implant loading affected the stability of miniscrew implants placed in proximity or contact with the adjacent root. The authors implemented finite element analysis (FEA) to examine the effectiveness of root proximity and root contact. Stress distribution in the bone was assessed at different degrees of root proximity by generating 4 finite element models: the implant touches the root surface, the implant was embedded in the periodontal membrane, the implant touches the periodontal surface, and the implant touches nothing. Finite element analysis was then carried out with simulations of 2 loading conditions for each model: condition A, involving only tooth loading and condition B, involving both tooth and implant loading. Under loading condition A, the maximum stress on the bone for the implant touching the root was the distinctly higher than that for the other models. For loading condition B, peak stress areas for the implant touching the root were the area around the neck of the mini implant and the point of the mini implant touches the root. The results of this study suggest that normal occlusal loading and implant loading contribute to the instability of the mini implant when the mini implant touches the root.

Influences of microgap and micromotion of implant-abutment interface on marginal bone loss around implant neck.

Science.gov (United States)

Liu, Yang; Wang, Jiawei

2017-11-01

To review the influences and clinical implications of micro-gap and micro-motion of implant-abutment interface on marginal bone loss around the neck of implant. Literatures were searched based on the following Keywords: implant-abutment interface/implant-abutment connection/implant-abutment conjunction, microgap, micromotion/micromovement, microleakage, and current control methods available. The papers were then screened through titles, abstracts, and full texts. A total of 83 studies were included in the literature review. Two-piece implant systems are widely used in clinics. However, the production error and masticatory load result in the presence of microgap and micromotion between the implant and the abutment, which directly or indirectly causes microleakage and mechanical damage. Consequently, the degrees of microgap and micromotion further increase, and marginal bone absorption finally occurs. We summarize the influences of microgap and micromotion at the implant-abutment interface on marginal bone loss around the neck of the implant. We also recommend some feasible methods to reduce their effect. Clinicians and patients should pay more attention to the mechanisms as well as the control methods of microgap and micromotion. To reduce the corresponding detriment to the implant marginal bone, suitable Morse taper or hybrid connection implants and platform switching abutments should be selected, as well as other potential methods. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Retrospective Analysis of Ruptured Breast Implants

Directory of Open Access Journals (Sweden)

Woo Yeol Baek

2014-11-01

Full Text Available BackgroundRupture is an important complication of breast implants. Before cohesive gel silicone implants, rupture rates of both saline and silicone breast implants were over 10%. Through an analysis of ruptured implants, we can determine the various factors related to ruptured implants.MethodsWe performed a retrospective review of 72 implants that were removed for implant rupture between 2005 and 2014 at a single institution. The following data were collected: type of implants (saline or silicone, duration of implantation, type of implant shell, degree of capsular contracture, associated symptoms, cause of rupture, diagnostic tools, and management.ResultsForty-five Saline implants and 27 silicone implants were used. Rupture was diagnosed at a mean of 5.6 and 12 years after insertion of saline and silicone implants, respectively. There was no association between shell type and risk of rupture. Spontaneous was the most common reason for the rupture. Rupture management was implant change (39 case, microfat graft (2 case, removal only (14 case, and follow-up loss (17 case.ConclusionsSaline implants have a shorter average duration of rupture, but diagnosis is easier and safer, leading to fewer complications. Previous-generation silicone implants required frequent follow-up observation, and it is recommended that they be changed to a cohesive gel implant before hidden rupture occurs.

Bone reactions at implants subjected to experimental peri-implantitis and static load. A study in the dog

DEFF Research Database (Denmark)

Gotfredsen, K; Berglundh, T; Lindhe, J

2002-01-01

during a 12-week interval, the screws were reactivated. Thus, the model included 3 different experimental sites of each surface group: group M+L (mucositis+load); group P (peri-implantitis); group P+L (peri-implantitis+load). Fluorochrome labels were injected and standardized radiographs obtained....... The animals were sacrificed and block biopsies of all implant sites dissected and prepared for histological analysis. RESULTS: It was demonstrated that the lateral static load failed to induce peri-implant bone loss at implants with mucositis and failed to enhance the bone loss at implants with experimental...... peri-implantitis. The proportion of bone labels and the bone density in the interface zone were significantly higher in group P+L than in group P. CONCLUSION: It is suggested that a lateral static load with controlled forces may not be detrimental to implants exhibiting mucositis or peri-implantitis....

Influence of surgical technique and surface roughness on the primary stability of an implant in artificial bone with different cortical thickness: a laboratory study.

NARCIS (Netherlands)

Tabassum, A.; Meijer, G.J.; Wolke, J.G.C.; Jansen, J.A.

2010-01-01

OBJECTIVE: The aim of this biomechanical study was to assess the interrelated effect of both surface roughness and surgical technique on the primary stability of dental implants. MATERIAL AND METHODS: For the experiment, 160 screw-designed implants (Biocomp), with either a machined or an etched

R&D on dental implants breakage

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Croitoru, Sorin Mihai; Popovici, Ion Alexandru

2017-09-01

Most used dental implants for human dental prostheses are of two steps type: first step means implantation and, after several months healing and osseointegration, second step is prosthesis fixture. For sure, dental implants and prostheses are meant to last for a lifetime. Still, there are unfortunate cases when dental implants break. This paper studies two steps dental implants breakage and proposes a set of instruments for replacement and restoration of the broken implant. First part of the paper sets the input data of the study: structure of the studied two steps dental implants based on two Romanian patents and values of the loading forces found in practice and specialty papers. In the second part of the paper, using DEFORM 2D™ FEM simulation software, worst case scenarios of loading dental implants are studied in order to determine which zones and components of the dental implant set are affected (broken). Last part of the paper is dedicated to design and presentation of a set for extracting and cutting tools used to restore the broken implant set.

Implantation, recoil implantation, and sputtering

International Nuclear Information System (INIS)

Kelly, R.

1984-01-01

The implantation and sputtering mechanisms which are relevant to ion bombardment of surfaces are described. These are: collision, thermal, electronic and photon-induced sputtering. 135 refs.; 36 figs.; 9 tabs

Medical implants and methods of making medical implants

Science.gov (United States)

Shaw, Wendy J; Yonker, Clement R; Fulton, John L; Tarasevich, Barbara J; McClain, James B; Taylor, Doug

2014-09-16

A medical implant device having a substrate with an oxidized surface and a silane derivative coating covalently bonded to the oxidized surface. A bioactive agent is covalently bonded to the silane derivative coating. An implantable stent device including a stent core having an oxidized surface with a layer of silane derivative covalently bonded thereto. A spacer layer comprising polyethylene glycol (PEG) is covalently bonded to the layer of silane derivative and a protein is covalently bonded to the PEG. A method of making a medical implant device including providing a substrate having a surface, oxidizing the surface and reacting with derivitized silane to form a silane coating covalently bonded to the surface. A bioactive agent is then covalently bonded to the silane coating. In particular instances, an additional coating of bio-absorbable polymer and/or pharmaceutical agent is deposited over the bioactive agent.

Implantation doping of GaN

International Nuclear Information System (INIS)

Zolper, J.C.

1996-01-01

Ion implantation has played an enabling role in the realization of many high performance photonic and electronic devices in mature semiconductor materials systems such as Si and GaAs. This can also be expected to be the case in III-Nitride based devices as the material quality continues to improve. This paper reviews the progress in ion implantation processing of the III-Nitride materials, namely, GaN, AlN, InN and their alloys. Details are presented of the successful demonstrations of implant isolation as well as n- and p-type implantation doping of GaN. Implant doping has required activation annealing at temperatures in excess of 1,000 C. The nature of the implantation induced damage and its response to annealing is addressed using Rutherford Backscattering. Finally, results are given for the first demonstration of a GaN device fabricated using ion implantation doping, a GaN junction field effect transistor (JFET)

Short dental implants versus standard dental implants placed in the posterior jaws: A systematic review and meta-analysis.

Science.gov (United States)

Lemos, Cleidiel Aparecido Araujo; Ferro-Alves, Marcio Luiz; Okamoto, Roberta; Mendonça, Marcos Rogério; Pellizzer, Eduardo Piza

2016-04-01

The purpose of the present systematic review and meta-analysis was to compare short implants (equal or less than 8mm) versus standard implants (larger than 8mm) placed in posterior regions of maxilla and mandible, evaluating survival rates of implants, marginal bone loss, complications and prosthesis failures. This review has been registered at PROSPERO under the number CRD42015016588. Main search terms were used in combination: dental implant, short implant, short dental implants, short dental implants posterior, short dental implants maxilla, and short dental implants mandible. An electronic search for data published up until September/2015 was undertaken using the PubMed/Medline, Embase and The Cochrane Library databases. Eligibility criteria included clinical human studies, randomized controlled trials and/or prospective studies, which evaluated short implants in comparison to standard implants in the same study. The search identified 1460 references, after inclusion criteria 13 studies were assessed for eligibility. A total of 1269 patients, who had received a total of 2631 dental implants. The results showed that there was no significant difference of implants survival (P=.24; RR:1.35; CI: 0.82-2.22), marginal bone loss (P=.06; MD: -0.20; CI: -0.41 to 0.00), complications (P=.08; RR:0.54; CI: 0.27-1.09) and prosthesis failures (P=.92; RR:0.96; CI: 0.44-2.09). Short implants are considered a predictable treatment for posterior jaws. However, short implants with length less than 8 mm (4-7 mm) should be used with caution because they present greater risks to failures compared to standard implants. Short implants are frequently placed in the posterior area in order to avoid complementary surgical procedures. However, clinicians need to be aware that short implants with length less than 8mm present greater risk of failures. Copyright © 2016. Published by Elsevier Ltd.

Implant-Abutment Contact Surfaces and Microgap Measurements of Different Implant Connections Under 3-Dimensional X-Ray Microtomography.

Science.gov (United States)

Scarano, Antonio; Valbonetti, Luca; Degidi, Marco; Pecci, Raffaella; Piattelli, Adriano; de Oliveira, P S; Perrotti, Vittoria

2016-10-01

The presence of a microgap between implant and abutment could produce a bacterial reservoir which could interfere with the long-term health of the periimplant tissues. The aim of this article was to evaluate, by x-ray 3-dimensional microtomography, implant-abutment contact surfaces and microgaps at the implant-abutment interface in different types of implant-abutment connections. A total of 40 implants were used in this in vitro study. Ten implants presented a screw-retained internal hexagon abutment (group I), 10 had a Morse Cone taper internal connection (group II), 10 another type of Morse Cone taper internal connection (group III), and 10 had a screwed trilobed connection (group IV). In both types of Morse Cone internal connections, there was no detectable separation at the implant-abutment in the area of the conical connection, and there was an absolute congruity without any microgaps between abutment and implant. No line was visible separating the implant and the abutment. On the contrary, in the screwed abutment implants, numerous gaps and voids were present. The results of this study support the hypothesis that different types of implant-abutment joints are responsible for the observed differences in bacterial penetration.

[Bilateral cochlear implants].

Science.gov (United States)

Müller, J

2017-07-01

Cochlear implants (CI) are standard for the hearing rehabilitation of severe to profound deafness. Nowadays, if bilaterally indicated, bilateral implantation is usually recommended (in accordance with German guidelines). Bilateral implantation enables better speech discrimination in quiet and in noise, and restores directional and spatial hearing. Children with bilateral CI are able to undergo hearing-based hearing and speech development. Within the scope of their individual possibilities, bilaterally implanted children develop faster than children with unilateral CI and attain, e.g., a larger vocabulary within a certain time interval. Only bilateral implantation allows "binaural hearing," with all the benefits that people with normal hearing profit from, namely: better speech discrimination in quiet and in noise, as well as directional and spatial hearing. Naturally, the developments take time. Binaural CI users benefit from the same effects as normal hearing persons: head shadow effect, squelch effect, and summation and redundancy effects. Sequential CI fitting is not necessarily disadvantageous-both simultaneously and sequentially fitted patients benefit in a similar way. For children, earliest possible fitting and shortest possible interval between the two surgeries seems to positively influence the outcome if bilateral CI are indicated.

Comparison of Persian Simple Vowels Production in Cochlear Implanted Children Based on Implantation Age

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Peiman Zamani

2008-07-01

Full Text Available Objective: Age at implantation is one of the most important factors in improving speech and language skills in children with cochlear implants. Moreover, good vowel articulation is very important in the speech. So, the purpose of this research was to determine whether age at cochlear implantation influences the production of Persian simple vowels when cochlear implantation is undertaken below the age of 2 years as compared with cochlear implantation later in life. Materials & Methods: This research was a comparative and cross-sectional study. Based on inclusive and exclusive criteria (i.e., have physical and mental health, monolingual or bilingual, have 9±1 months post-surgery rehabilitation, no hearing handicapped parents and no medical problems history, 140 children who cochlear implanted in Amir-Alam and Hazrate Rasool hospital of Tehran city were selected by convenient sampling and assigned to two groups, children implanted under the age of 2 years and those implanted above the age of 2 years Also 238 normally hearing children were selected for control group by randomized sampling. The first and second formant frequency (F1 & F2 of the Persian simple vowels /i, e, æ, a, o, u/ were evaluated by the version of 1.2 of SFSwin software. Data were analyzed by Independent T test. Results: The findings indicated that there were significant differences between two groups in the mean of F2/i/ (P=0.046, F1/e/ (P=0.011, F2/e/ (P=0.005, F2/æ/ (P=0.039, F2/a/ (P=0.012, F2/o/ (P=0.012 and F2/u/ (P=0.006, but there was no significant difference between then in the mean of F1/i/, F1/æ/, F2/a/, F1/o/, F1/u/ (P>0.05. According to these results, no significant difference was seen between normal group and children who received their cochlear implants under the age of 2 years in the mean of variables (P>0.05. Conclusion: Observing significant differences in the quality of the production of Persian simple vowels between children implanted under the age of 2

Azygos Vein Lead Implantation For High Defibrillation Thresholds In Implantable Cardioverter Defibrillator Placement

Directory of Open Access Journals (Sweden)

Naga VA Kommuri

2010-01-01

Full Text Available Evaluation of defibrillation threshold is a standard of care during implantation of implantable cardioverter defibrillator. High defibrillation thresholds are often encountered and pose a challenge to electrophysiologists to improve the defibrillation threshold. We describe a case series where defibrillation thresholds were improved after implanting a defibrillation lead in the azygos vein.

An Unusual Bone Loss Around Implants

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Amirreza Rokn

2013-01-01

Full Text Available AbstractPre-implant disease is an inflammatory process, which can affect the surrounding tissues of a functional Osseointegrated implant that is usually as a result of a disequilibrium between the micro-flora and the body defense system.This case reports a 57 years old male with unusual bone loss around dental implants.This was an unusual case of peri-implantitis which occurred only in the implants on one side of the mouth although they all were unloaded implants.

Determining factors for implant referral rates.

Science.gov (United States)

Levin, Roger P

2002-01-01

The research findings indicate that the field of implant dentistry will only grow at a moderately low level unless certain changes are made. Findings indicated that the effort by the implant companies has been nothing short of dramatic, and yet almost 60% of restorative doctors do not participate annually in any implant case. There was no clear indication that younger restorative doctors will significantly increase the number of implant referrals, as their overall implant education has not dramatically differed from those dentists who graduated in earlier years. Once the research was completed, it became obvious to Levin Group that the driving force behind implant referral growth will be implant surgeons, because of their one-to-one relationship with restorative doctors. The Levin Group Implant Management and Marketing Consulting Program is based on approaching restorative doctors in several different levels, starting with awareness all the way through to case facilitation and long-term tracking and communication. Finally, a continuing marketing/education effort needs to be consistently in place with effective materials, not only to create a high level of awareness, but also to motivate restorative doctors to refer cases and then work through the case with the implant surgeon to a satisfactory completion for the restorative doctor, implant surgeon, and patient. While the surgical insertion of implants may seem to carry a high-profit margin relative to the restoration of implants, the truth is that the restoration of implants usually provides a 40% higher profit margin for the restorative doctor than traditional dental services. One of the key issues is that referring doctors have not necessarily learned how to set fees and present cases with regard to implant dentistry. The key factor here is to ensure that the patient understands that implant services involve higher fees than traditional services, because of the necessarily higher levels of experience, education

Silicone implant incompatibility syndrome (SIIS) in a 57-year-old woman with unilateral silicone breast implant

DEFF Research Database (Denmark)

Schierbeck, Juliane; Davidsen, Jesper Rømhild; Grindsted Nielsen, Sanne

2017-01-01

implants can lead to different interstitial lung manifestations predominantly with granuloma evolvement, leading to the so-called silicone implant incompatibility syndrome (SIIS). This case describes a 57-year-old woman with multiple lung infiltrations and a left-sided breast implant. The implant had been...