bluuebunny/crossref_metadata_2025 huggingface dataset:
On-Demand ELT Architecture for Right-Time BI
Authors: Waas Florian , Wrembel Robert , Freudenreich Tobias , Thiele Maik , Koncilia Christian , Furtado Pedro
Published: July 2013

In a typical BI infrastructure, data, extracted from operational data sources, is transformed, cleansed, and loaded into a data warehouse by a periodic ETL process, typically executed on a nightly basis, i.e., a full day’s worth of data is processed and loaded during off-hours. However, it is desirable to have fresher data for business insights at near real-time. To this end, the authors propose to leverage a data warehouse’s capability to directly import raw, unprocessed records and defer the transformation and data cleaning until needed by pending reports. At that time, the database’s own processing mechanisms can be deployed to process the data on-demand. Event-processing capabilities are seamlessly woven into our proposed architecture. Besides outlining an overall architecture, the authors also developed a roadmap for implementing a complete prototype using conventional database technology in the form of hierarchical materialized views.
Managing SaaS Risk in Higher Education Organisations
Authors: Troshani Indrit , Rampersad Giselle , Wickramasinghe Nilmini
Published: July 2013

Software-as-a-Service (SaaS) is a new information and communications technology (ICT) that offers dynamically scalable reconfigurable services to clients on demand via the internet. It is heralded as one of the most significant ICT advances that can facilitate business value creation and innovation. There is paucity of research concerning the perceived risks that can affect SaaS adoption intentions of higher education organisations (HEOs). In attempts to contribute to the existing body of knowledge, this study draws on qualitative evidence to explore perceived SaaS risks at HEOs. It equips HEO managers and policy makers with an integrative risk management framework for SaaS adoption.
Comparing Mobile and Internet Adoption Factors of Loyalty and Satisfaction with Online Shopping Consumers
Authors: Amoroso Donald L. , Ogawa Mikako
Published: July 2013

This research looks at the adoption of Internet and mobile applications comparing the factors that influence loyalty and satisfaction. It is the intent of this exploratory study to examine factors of adoption that are common in both Japan and the United States. After a comprehensive review of the literature, we derived a research model for and tested related hypotheses with data collected from consumers in both Japan and the United States. The authors used online shopping as the common application between Internet and mobile technologies. They found that the original technology acceptance model factors to be less important in explaining the overall variance of satisfaction, especially with mobile applications, than expected. This research takes an important first step in understanding the adoption of online shopping by differentiating mobile and Internet factors. Inertia was found to be critical in explaining satisfaction only with mobile applications. This factor is important for online retailers who count on repeat sales as a major part of their revenue. Loyalty is key to online retailers identifying the factors that will enhance the satisfaction of the online consumer. This study provides managers with a framework for online shopping which areas they need to focus upon when launching new online products, such as shaping and/or changing their consumers’ attitude toward using the Internet, making their Website easier to use, and enhancing the perceived usefulness of the technologies that allow consumers to access their products online.
An E-Government Approach for Bridging the Participation Gap in Achieving Participatory Good Governance
Authors: Waheduzzaman  , Miah Shah Jahan
Published: July 2013

Electronic Government (e-Government) has been considered as an essential strategy for many governments in their efforts to ensure qualities of participatory good governance. Various e-Government applications have been recognised as effective methods of enhancing governance qualities, such as accountability, transparency, collaboration and trust. However, previous studies that focused on participatory good governance are so far limited, especially in bringing an e-Government solution strategy using a bottom-up approach. Using a qualitative case study1 this paper identifies a participation gap in achieving participatory good governance and aims to address this gap through an e-Government approach in rural sector of a developing country. The outcomes of the study demonstrate that e-Government strategy can play a significant role to address the participation-gap in implementing qualities of good governance.
The Impact of Different Organizational Cultures on IT Outsourcing Relationship Management
Authors: Aasi Parisa , Nunes Ivan , Rusu Lazar , Hodosi Georg
Published: July 2013

Globalization has affected the organizations in many aspects such as structure, architecture, internal/external strategies and sourcing management. Outsourcing is one of the recent business strategies used to provide IT needs via external agents. The relationship between the service buyer and provider companies is a constituent playing a significant role in IT outsourcing success or failure. This research has a focus on the influence of organizational culture of buyer companies on the specific factors of trust, cooperation, communication and commitment in their relationship with the IT service provider. Two explorative case studies are done in global companies using ITO which revealed the presence of organizational culture effect. Particularly, being innovative, having open discussion as an organizational culture and looking for extending contracts with providers as a strategy, appeared as the major difference between the two cases organizational culture; which influences the studied factors of ITO relationship in this research.
Sociotechnical Framework for Participatory Flood Risk Management via Collaborative Modeling
Authors: Jonoski Andreja , Evers Mariele
Published: July 2013

This article introduces a sociotechnical framework for conceptualization, design and development of participatory Flood Risk Management (FRM) processes. The framework enables a collaborative modeling approach, in which FRM activities are jointly carried out by authorities responsible for FRM, key stakeholders and the potentially affected citizens. Given the technical and social complexity of FRM, the article argues for adoption of the proposed framework as a means for realizing individual and social learning among all involved actors, which leads to shared understanding of the identified flood risks and potentially to commonly agreed FRM alternatives and strategies. Implementation of the framework critically depends on a web-based collaborative platform – a tool that supports all collaborative modeling activities. The framework is presented from within European context of FRM, but its relevance is broader and it can potentially be adopted in other social and geographical areas.
Relationships in Technological Processes
Authors: Cua Francisco , Reames Steve , Chai Joe Choon Yean
Published: July 2013

The process model and theory of Diffusion of Innovations (DOI) and the new idea of how technology spreads in an organization are discussed. A comparison between DOI and the Relationship Marketing (RM) theory is examined. Managers who desire innovation or utilize RM theory for third-party change agents are explored. Request for Information (RFI), and Request for Proposal (RFP) utilized by managers that desire technological innovation in the procurement process is discussed. A case study of the commercialization, innovation, feedback-assessment procurement processes of the DOI is conducted in a large public-sector university that procured and implemented an Enterprise Resource Planning (ERP) system. The study revealed that the innovation process was inadequate to explain the outcome. The conclusion reveals that an opportunity or a threat is co-dependent on how each party perceives on or the other’s premise; either premise is irrelevant if one side or the other refuses to foster the relationship.
Blended Learning in Personalized Assistive Learning Environments
Authors: Marinagi Catherine , Skourlas Christos
Published: July 2013

In this paper, the special needs/requirements of disabled students and cost-benefits for applying blended learning in Personalized Educational Learning Environments (PELE) in Higher Education are studied. The authors describe how blended learning can form an attractive and helpful framework for assisting Deaf and Hard-of-Hearing (D-HH) students to learn and communicate. The described blended learning experiment integrates face-to-face, synchronous, and asynchronous e-learning, bilingual teaching (oral language and Sign Language) in the mainstream class, teaching in parallel classes, and personalized access to distributed databases of educational material. At the core of PELE, the authors use Multimedu, a web-based tailored made tool for disabled students. This experimental tool includes applications of a traditional Learning Management System (LMS), supporting a multilingual dictionary of terms, multimedia management and social networking. Finally, this paper describes the use of the blended e-learning model in “Database I” course, given at the Technological Educational Institute of Athens, Greece.
Grey-Based Taguchi Analysis for Optimization of Multi-Objective Machining Process in Turning
Authors: Kalsi Nirmal S. , Sehgal Rakesh , Sharma Vishal S.
Published: July 2013

In the present experimental study, Taguchi method and the GRA (grey relation analysis) technique were used to optimize a multi-objective metal cutting process to yield maximum performance of tungsten carbide-cobalt cutting tool inserts in turning. L18 orthogonal array was selected to analyze the effect of cutting speed, feed rate and depth of cut using cryogenically treated and untreated inserts. The performance was evaluated in terms of main cutting force, power consumption, tool wear and material removal rate using main effect plots of S/N (signal to noise) ratios. This study indicated that grey based Taguchi technique is not only a novel, efficient and reliable method of optimization, but also contributes to satisfactory solution for multi machining objectives in turning process. It is concluded that cryogenic treated cutting tool inserts performed better. However, the feed rate affected the process performance most significantly.
Self-Evaluation E-Learning System for Manufacturing Engineering Subjects
Authors: Morales-Palma D. , Centeno G. , Vallellano C. , Doblas F.J. , Martínez-Donaire A.J. , Estévez A. , García-Lomas F.J.
Published: July 2013

This work presents a project of teaching innovation on the subject Technology of Manufacturing that has been developed for the last five years. The objective is to stimulate students for training through a self-evaluation system based on e-learning tools, in agreement with the guidelines of the European Higher Education Area (EHEA). The system includes a methodology to perform a series of evaluations about theoretical and practical knowledge which allows the student self-learning. The data obtained with the proposed system are analyzed and the effect on student results is discussed. The evolution in time of the student grades, their involvement and satisfaction with the project, and its influence in their final score are presented.
Preparation of Copper Nanoparticles by Pulsed Wire Discharge in Water
Authors: Tokoi Yoshinori , Nagasawa Shinobu , Suematsu Hisayuki , Cho Hong Baek , Nakayama Tadachika , Niihara Koichi
Published: July 2013

Copper nanoparticles have been prepared by pulsed wire discharge (PWD) using copper wire in deionized water at various relative energy (K) from 0.8 to 5.5, which is ratio of the charged energy of capacitor in the electrical circuit to the vaporization energy of the wire. From the X-ray diffraction analysis of the prepared nanoparticles in deionized water at various K, the nanoparticles prepared at all conditions were identified as Cu and Cu2O. The Cu content in prepared nanoparticles was increased with the decrease in K, and changed from 77 to 95 [%]. Additionally, the deposited energy in the arc discharge after the wire heating was decreased with decreasing K. From these results, we considered that the Cu content was increased with decreasing the deposited energy in the arc discharge during particle formation.
Fabrication and Thermoelectric Properties of Al-Doped (ZnO)5In2O3 by Microwave Heating
Authors: Endo Tomoyuki , Hayashi Yamato , Fukushima Jun , Takizawa Hirotsugu
Published: July 2013

Various (ZnO)5In2O3ceramics were fabricated by microwave heating. Density, XRD pattern and microstructure were examined and those of Al-doped (ZnO)5In2O3were almost the same as Al-free one. Highly textured (ZnO)5In2O3ceramic was also fabricated by reactive templated grain growth (RTGG) method. The electrical conductivity was not improved by Al-doping; however it was improved slightly by microwave heating compared with conventional heating and especially improved by texturing using RTGG method. On the other hand, the absolute Seebeck coefficient in microwave heating was improved about 25% by Al-doped. Maximum electric power factor of textured specimen fabricated by RTGG method along ab-plane showed 5.76×10-4WK-2m-1(at 873K), which was attributed to high electrical conductivity.
Numerical Study on the Removal of Hydrogen and Nitrogen from the Melt of Medium Carbon Steel in Vacuum Tank Degasser
Authors: Yu Shan , Miettinen Jyrki , Louhenkilpi Seppo
Published: July 2013

The steelmaking field has been seeing an increased demand of reducing hydrogen and nitrogen in liquid steel before casting. This is often accomplished by vacuum treatment. This paper focuses on developing a numerical model to investigate the removal of hydrogen and nitrogen from the melt of medium carbon steel in a commercial vacuum tank degasser. An activity coefficient model and the eddy-cell expression are implemented in the ANSYS FLUENT code to compute the activities of related elements and mass transfer coefficients of hydrogen and nitrogen in liquid steel. Several cases are simulated to assess the effect of gas flow rate and initial nitrogen content in liquid steel on degassing process and the calculated results are compared with industrial measured data.
Conditions for Consistent Implementation of Flow Stress Models Incorporating Dynamic Recrystallization into Finite Element Simulation Codes
Authors: Bambach Markus
Published: July 2013

Dynamic recrystallization (DRX) is widely used in industrial hot working processes to control the microstructure and properties of the workpiece and to keep the forming forces low. For the analysis and design of metal forming processes powerful simulation methods, must notably the Finite Element (FE) method, have been developed. Various models are available that consider the coupled evolution of microstructure and flow stress during hot deformation processes. Some of these models have been implemented into FE codes and are widely available now. However, for the implementation of flow stress models incorporating DRX into an FE formulation, special smoothness requirements exist that are not automatically fulfilled by the available flow stress models. This work reviews some conditions that a flow stress model incorporating DRX has to fulfill in order to be consistently embedded into an FE code for large plastic deformation. A specific Sellars-type model is analyzed for consistency with these conditions. It is shown that the use of a classical JMAK equation for the DRX kinetics within these models is problematic for Avrami exponents smaller than or equal to 3, for which the flow stress model is not sufficiently smooth. DRX kinetics based on the work of Cahn are proposed to remedy the differentiability issues.
The Thermomechanical Controlled Processing of High-Strength Steel Plate: A New View of Toughness Based on Modern Metallography
Authors: Liang Xiao Jun , Hua Ming Jian , Garcia C. Isaac , DeArdo Anthony J.
Published: July 2013

Modern thermomechanical controlled processing (TMCP) of advanced steels is now an important processing route in the production of engineering structures and products that are of value to society. The principles of TMCP are now practiced in the hot mill, cold mill and press forming shops around the world. Successful TMCP means that the proper metallurgical microstructure has been obtained in the required areas of the steel. The ideal microstructure is often defined by the correct phase balance and dimensions either of the parent austenite or final ferritic phase. Technological and economic demands have led to ever increasing levels of strength, especially for applications such as large diameter linepipe. The operative yield strengths in 18mm hot rolled plate have increased from X52(ferrite pearlite) in 1970 to X80(ferrite-bainite) today. The next frontier is the X100-X120 strength range, where bainitic or martensitic microstructures are required. It is clear that achieving a high-strength bainitic microstructure in heavy plate requires a high Carbon Equivalent value (C. E. II or Pcm), a rapid cooling rate, and a low water-end temperature. The requirement of high toughness and good weldability also means a low carbon content. This paper will describe the results of a research program where a steel of C. E. 0.56 and Pcm 0.23 was reheated, rough rolled for grain refinement, finish rolled for austenite pancaking, and direct quenched to below the Bs temperature. It was found that the strength and especially the toughness of the fully processed plates could not be explained using conventional metallographic techniques in conjunction with known structure-property relationships. However, the application of modern metallographic techniques based on FEG-SEM incorporating OIM led to microstructural characterization that more fully explained the observed mechanical properties. Of particular importance were the amount of MA micro-constituent, the crystallographic packet size of the bainite, and the high angle boundary character, especially the CSL boundaries, found in the microstructure. In the future, improved modeling of microstructural evolution and attendant mechanical properties will incorporate these important features.
Tensile Testing of Ti-6Al-4V Alloy Superplasticity
Authors: Aksenov Sergey A. , Chumachenko Eugene N. , Logashina Irina V.
Published: July 2013

This paper presents the research on the flow characteristics of the Ti-6V-4Al alloy in wide ranges of temperature (725 ‑ 950 °C) and strain rate (10-5 ‑ 10-2 s-1). The material processing maps were constructed based on the basis of dynamic materials model (DMM) developed by Prassad and modified by Narayana Murty. For the construction of such maps the data of the material flow stress at different temperatures and strain rates is necessary. To obtain such data the stepped tensile tests which allow obtaining the stress - strain rate dependence at a given temperature are ideal. The experiments conducted consist of the tensile test series at various temperatures with stepped change of the deformation rate. By the results of these tests the constitutive equations, which describe relationship between stress and strain rate for each temperature, were obtained. The data was analyzed in terms of the two different approaches proposed by Prassad and Narayana Murty to assess the impact of deformation conditions on the formability and flow stability of the material. Based on these approaches, the processing maps, which enable identifying the conditions of the Ti-6V-4Al alloy superplasticity, were constructed.
Microstructure and Strength of Si3N4 Joints Bonded with Sialon-Oxynitride Glass
Authors: Liu Chun Feng , Zhang Jie , Guo Yong Liang , Yuan Xiao Dong , Huang Yu Dong
Published: July 2013

Si5.4Al0.6O0.6N7.4(β-Sialon)/ Y1.75Si2.625Al1.0O7.5N1.25(oxynitride glass) composite solders with different ratio were designed using SiO2-Al2O3-AlN-Y2O3-Si3N4mixture powders to join Si3N4ceramic to itself. It was found that both solder composition and bonding temperature have strong influence on the microstructure and strength of the joints. As far as using a pure oxynitride glass solder was concerned, the thickness of the seam turned narrow with the increase of temperature, and the strength had a peak value at 1550 °C. When increasing the designed content of β-Sialon, serious composition separation occurred in the seam at low bonding temperatures, and the strength was also lower than as using pure oxynitride glass. Increasing bonding temperature, the strength of the joints was improved and reached the maximum value of near 80 MPa at 1600 °C for the designed 20%β-Sialon. In this instance, large amounts of fine elongated β-Sialon grains were uniformly distributed in the seam. However, for the 60%β-Sialon containing solder, some pores appeared in the seam and its strength was very low at bonding temperatures.
On the Modelling of a Pulsed TIG Weld Process in a Nickel Superalloy
Authors: Turner Richard , Huang Jiang Lin , Ward Mark , Villa Matteo , Reed Roger C.
Published: July 2013

The nickel-based superalloy C263 is commonly used within Aeroengine manufacture for various casing components. FE weld simulation methods using the commercial code Sysweld2012 have been developed to attain better understanding of a pulsed TIG welding process. Test-plate welds are performed and cross-sectioned for metallographic analysis. The welds are modelled as steady-state, continuous welding heat sources. The heat sources used in the models considered a modified 3D conical distribution, and are best-fitted against the fusion-zone boundary measured in the cross-sections. A reasonable agreement between fusion zone boundaries for the modelled predictions and the experimental cross-sections was achieved, demonstrating that the pulsed TIG weld application can be reasonably modelled using a steady-state heating.
Numerical Simulation of SAW Heat Source in the External Longitudinal Magnetic Field in 16Mn Steel
Authors: Chang Yun Long , Lu Lin , Liu Xiao Long , Lee Bo Young
Published: July 2013

The finite element analysis on temperature field and stress field during submerged-arc welding (SAW) was carried out by means of assembly language of FORTRAN on the base of ABAQUS. A finite element model was established to study the effects on weld bead formation by using longitudinal magnetic field of low-frequency and different process parameters loaded with moving heat source. A practical SAW experiment was conducted to verify the results of the numerical simulation. It was shown that a molten pool with a wider weld face and a lower penetration could be obtained by the control of longitudinal magnetic field of low-frequency. In addition, the fusion line after this treatment was smoother than with conventional SAW. The results of practical SAW experiment were consistent with those of the numerical simulation. It was confirmed that the longitudinal magnetic field of low-frequency could contribute in diminishing the dilution rate and improving the performance of surfacing layers.
Thirst in Critically Ill Patients: From Physiology to Sensation
Authors: Arai Shoshana , Stotts Nancy , Puntillo Kathleen
Published: July 2013

Critically ill patients often report distressful episodes of severe thirst, but the complex biochemical, neurohormonal mechanisms that regulate this primal sensation still elude clinicians. The most potent stimuli for thirst are subtle increases in plasma osmolality. These minute changes in osmolality stimulate central osmoreceptors to release vasopressin (also known as antidiuretic hormone). Vasopressin in turn acts on the kidneys to promote the reabsorption of water to correct the increased osmolality. If this compensatory mechanism fails to decrease osmolality, then thirst is triggered to motivate drinking. In contrast, thirst induced by marked volume loss, or hypovolemic thirst, is subject to the tight osmoregulation of the renin-angiotensin aldosterone system and accompanying adrenergic agonists. Understanding the essential role that thirst plays in salt and water regulation can provide clinicians with a better appreciation for the complex physiology that underlies this intense sensation.
Thematic Analysis of Cardiac Care Patients’ Explanations for Declining Contribution to a Genomic Research-Based Biobank
Authors: Williams Pamela Holtzclaw , Nemeth Lynne S. , Sanner Jennifer E. , Frazier Lorraine Q.
Published: July 2013

Background

Health care delivery systems increasingly ask patients to contribute biological samples for future genomic-based health research during critical care admissions, as the result of genome-based research requirements of unprecedented large sample sizes. Few reports describe patients’ perceptions and responses to actual biobanking approaches in clinical settings. A qualitative study was conducted to explore 568 cardiac care patients’ explanations of why they declined to contribute their samples to a future genomic research biobank.

Objectives

To (1) identify themes emerging from explanations for declining contribution to the research biobanking initiative and (2) determine how the content informs the stewardship conceptual framework that addresses evidence-based clinical ethics practices in genomic and genetic research biobanking.

Methods

This qualitative study used an analytic method that combines inductive and deductive approaches to identify themes in patients’ explanations for declining to contribute to a research biobank initiative. The hybrid design has relevance to health services research that seeks to develop taxonomy, themes, and theory.

Results

Inductive approaches showed that themes of intrusion and autonomy dominated explanations. Deductive approaches affirmed previously proposed elements of a stewardship conceptual framework that addresses ethics in biobanking.

Conclusion

Research in understanding patients’ perceptions can guide nursing and biobank practices in developing best practices.
Clinico-radiologic Findings in Group II Caudal Regression Syndrome
Authors: Sharma Pankaj , Kumar Sheo , Jaiswal Awdesh
Published: June 2013

Caudal regression syndrome (CRS) is a rare congenital abnormality in which a segment of the lumbo-sacral spine and spinal cord fails to develop. The severity of the morphologic derangement inversely correlates with residual spinal cord function. We present a case report of a 10-year-old girl with Group 2 CRS, to emphasize clinical and radiologic findings in this rare abnormality.
In vitro Comparative Study of the Microbial Leakage of One-step, Thermafil and Lateral Condensation Techniques
Authors: Jafarzadeh Hamid , Habibi Mehdi , Bakhtiar Hengameh , Heidari Neda , Mehrvarzfar Peiman , Ghazvini Kiarash , Dastmalchi Nafiseh
Published: June 2013

Aim

To compare the apical seal of lateral condensation technique, thermafil and one-step by using this model.

Materials and methods

A two-chamber bacterial microleakage model using E. faecalis as microbial marker was used for evaluation of the leakage. Bacterial penetration was monitored over a 60-day period. Leakage was recorded when turbidity was observed in the lower chamber.

Results

After comparing the bacterial penetration values, total penetration was observed 45% in lateral condensation technique, 80% in thermafil and 75% in one-step. There was no significant difference between groups after 60 days; however, the microleakage in lateral condensation group was seen later than one-step and thermafil.

Conclusion

Thermafil and one-step obturator can be advocated as effective obturation techniques for achieving predictable success in endodontic therapy.

Clinical significance

Thermafil and one-step obturator are suitable devices for obturation.

How to cite this article

Bakhtiar H, Heidari N, Mehrvarzfar P, Ghazvini K, Habibi M, Jafarzadeh H, Dastmalchi N.In vitroComparative Study of the Microbial Leakage of One-step, Thermafil and Lateral Condensation Techniques. J Contemp Dent Pract 2012;13(1):27-30.
Comparative Evaluation of Few Physical Properties of Epoxy Resin, Resin-Modified Gypsum and Conventional Type IV Gypsum Die Materials: An in vitro Study
Authors: Gujjarlapudi Manmohan Choudary , Reddy S Varalakshmi , Madineni Praveen Kumar , Nunna Venkata Narayana , Manne Sanjay Dutt
Published: June 2013

Aim

To compare and evaluate few physical properties of epoxy resin, resin-modified gypsum and conventional type-IV gypsum die material.

Materials and methods

In the present study, dimensional accuracy, surface detail reproduction and transverse strength of three die materials like epoxy resin (Diemet-E), resin-modified gypsum (Synarock) and conventional type-IV gypsum (Ultrarock) are analyzed. For dimensional accuracy, master die (Bailey's die) is used and calibrations were made with digital microscope. For surface detail reproduction and transverse strength, rectangular stainless steel master die (Duke's die) was used and calibrations were made with Toolmaker's microscope and Instron universal testing machine respectively. One-way analysis of variance (ANOVA) was performed on the means and standard deviation for groups of each test.

Results

The results of the study showed statistically significant difference among these materials in dimensional accuracy, surface detail reproduction and transverse strength.

Conclusion

Epoxy resin exhibited superiority in dimensional accuracy, surface detail reproduction and transverse strength and is nearest to the standards of accurate die material.

How to cite this article

Gujjarlapudi MC, Reddy SV, Madineni PK, Ealla KKR, Nunna VN, Manne SD. Comparative Evaluation of Few Physical Properties of Epoxy Resin, Resin- Modified Gypsum and Conventional Type IV Gypsum Die Materials: An in vitro Study. J Contemp Dent Pract 2012;13(1): 48-54.
Comparison of Antimicrobial Activities and Compressive Strength of Alginate Impression Materials following Disinfection Procedure
Authors: Alwahab Zahraa
Published: June 2013

Aim

This study investigated the effectiveness of disinfecting solution when incorporated into alginate powder instead of water against some microorganisms and on compressive strength of alginate.

Materials and methods

For measuring antimicrobial activity of alginate, 60 alginate specimens were prepared and divided into two groups: One with water incorporated in the mix (control) and the other with 0.2% chlorhexidine digluconate incorporated in the mix instead of water. The tested microorganisms were: Gram +ve cocci, Gram –ve bacilli and yeast (each group 10 samples). For measuring compressive strength, 20 specimens of alginate were divided into two groups: One with water incorporated in the mix (control) and the other with chlorhexidine incorporated in the mix.

Results

The statistical analysis of antimicrobial efficacy of alginate was performed with Mann-Whitney U-test, which revealed very high significant difference when comparing among groups (p < 0.000). Student t-test analyzed the compressive strength data which revealed nonsignificant difference between groups (p > 0.05).

Conclusion

The incorporation of disinfecting agents into impression materials could serve an important role in dental laboratory infection control and it had no adverse effect on compressive strength of the hydrocolloid alginate.

Clinical significance

The risk of transmitting pathogenic microorganisms to dental laboratories via impression has been considered a topic of importance for a number of years.

How to cite this article

Alwahab Z. Comparison of Antimicrobial Activities and Compressive Strength of Alginate Impression Materials following Disinfection Procedure. J Contemp Dent Pract 2012;13(4):431-435.
Microbial Colonization and their Relation with Potential Cofactors in Patients with Denture Stomatitis
Authors: Jawale Bhushan Arun , Redasani Rahul , Chaudhari Lalit , Chopde Narendra , Pharande Amol , Hiremath Vardha
Published: June 2013

Aim

To determine microbial prevalence in the mucous membrane and prosthesis of denture wearers with and without denture stomatitis and to study its relationship with potential clinical cofactors.

Materials and methods

Saliva was collected from 200 patients (100 female and 100 male) wearing dental prosthesis for measurement of pH. Oral samples of the mucous membrane and of dentures were taken with sterile swab for microbiological analysis. Medical and dietary history of the subjects was recorded. Chi-square test and analysis of varience were used for statistical analysis.

Results

Diabetes, hypertension and high carbohydrate ingestion was observed in majority of patients. The pH average in saliva was of 5.1. The presence of C. albicans, S. aureus and S. mutans in the mucous membrane was of 55.4, 56.4 and 63.6% respectively. C. albicans was isolated in 69.7% from the prosthesis, whereas S. aureus and S. mutans were isolated in 45.3%. The isolation of C.albicans was more frequent in patients with deture stomatitis.

Conclusion

C. albicans, S. aureus and S. mutans frequently colonize the oral mucous of denture wearers. This is more frequently observed in patients with denture stomatitis.

Clinical significance

Denture stomatitis is associated to Candida albicans, different bacteria and other cofactors, such as salivary pH, carbohydrate ingestion, systemic illnesses and medication.

How to cite this article

Chopde N, Jawale B, Pharande A, Chaudhari L, Hiremath V, Redasani R. Microbial Colonization and their Relation with Potential Cofactors in Patients with Denture Stomatitis. J Contemp Dent Pract 2012;13(4):456-459.
The Effect of Different Curing Time Regimens on Immediate Postpolymerization Color Changes of Resin Composites
Authors: Mir Arash Poorsattar Bejeh , Mir Morvarid Poorsattar Bejeh
Published: June 2013

Aim

Light curing of resin composites may considerably change the color of resin composites. The aim of this study was to evaluate the changing pattern of resin composite's color by different curing times.

Materials and methods

Fifteen, 1 mm-thick, samples of each A2 shade Clearfill and Filtek P60 composites were prepared. First five samples were cured for 10s (400 mW/cm2) in each pole of the rectangular samples (right upper, right lower, left lower, left upper plus central zone). Consecutive sets of samples, each consists of five, were irradiated by doubling and tripling the curing time to 20 and 30s. Color change were measured by means of CIE 1976 L*a*b system equation (ΔE) for each digitalized picture of the corresponding sample.

Results

Color of samples was clinically significant changed by increasing the curing time from 10 to 20s and from 20 to 30s for Clearfil (ΔE = 13.86 and 14.11 respectively,) and Filtek P60 (ΔE = 7.68 and 11.66 respectively). The ‘b’ component change was responsible for the most color alteration confirmed by the linear regression model (p < 0.001).

Conclusion

This study revealed the contrasting pattern of resin composite's color change with the different curing times. Our findings support that light curing is accompanied by a higher attained blue chroma and diminished yellowness of resin composites.

Clinical significance

A complete and proper curing of sample resin composites on buccal surface of particular tooth, as a common practice to ensure the maximize concordance composite and tooth color, is reassured according to the considerable differences of undercured and overcured in comparison to normocured composite.

How to cite this article

Poorsattar Bejeh Mir A, Poorsattar Bejeh Mir M. The Effect of Different Curing Time Regimens on Immediate Postpolymerization Color Changes of Resin Composites. J Contemp Dent Pract 2012;13(4):472-475.
Comparative Analysis for Selection of Resin Luting Cements Based on Filler Content: An in vitro Study
Authors: Babu Mandava Ramesh , RaviKiran Vajapeyayajula , Vinod V , Saraswathi Devabhaktuni , Rao Venugopal N
Published: June 2013

Context

Resin luting of all-ceramic restorations results in increased performance; however, the strengthening mechanism and the role of the mechanical properties of the resin are not fully understood.

Objective

The aim of this study was to investigate the effect of filler content on the flexural properties of resin luting agents and thereby selecting an appropriate resin luting cement.

Materials and methods

Three esthetic resin luting agents studied were Calibra (Dentsply); RelyX ARC and Panavia F. Ten beam-shaped specimen (L × W × H: 30 × 8 × 2 mm) were made for each of the material tests carried out. The specimens were stored in distilled water for 24 hours at 37°C. The specimens were then tested for flexural strength (MPa) and flexural modulus (GPa) using the three-point bending method on a universal material testing machine at a cross head speed of 0.5 mm/min. Data obtained were statistically analyzed using ANOVA followed by post-hoc - Tukey's test with p < 0.05 for statistical significance.

Results

Increase in mean strength related to an associated increase in the elastic modulus which in turn was related to the filler loading of the resin luting cements.

Conclusion

Strength and performance of resin-cemented allceramic restoration can be enhanced by the use of a resin luting cement having increased filler content.

Clinical implications

Resin-composite cements may be most suitable for adhesively bonded restorations, where margins are placed on supragingival enamel, and where ultimate strength and energy absorption are paramount. The selection criteria for a resin cement depends on its flexural strength. To a great extent, the flexural strength is dependent on the filler loading of the resin luting cement.

Key message

Fracture of brittle all-ceramic restoration can be prevented by using resin luting cement with higher filler loading. In other words, any resin luting cement with higher filler content has an improved performance in terms of clinical function and durability.

How to cite this article

Babu MR, RaviKiran V, Vinod V, Saraswathi D, Rao VN. Comparative Analysis for Selection of Resin Luting Cements Based on Filler Content: An in vitro Study. J Contemp Dent Pract 2012;13(4):481-486.
Comparison of Shear Bond Strength of Metal Brackets Bonded to Porcelain Surface using Different Surface Conditioning Methods: An in vitro Study
Authors: Girish PV , Dinesh Uma , Bhat CS Ramachandra , Shetty Pradeep Chandra
Published: June 2013

Aim

To evaluate and compare the shear bond strength of metal brackets bonded to ceramic surfaces using different conditioning methods and to assess the site of bond failure after debonding.

Materials and methods

A total of 70 ceramic surfaces were produced with uniform shape, size and composition. The samples were divided into 7 groups (each of 10 samples).

Group 1 was the control group (untreated surface); in group 2 the surface were roughened with a diamond bur; in group 3 the surface were etched with hydrofluoric acid; in group 4 the surfaces were sandblasted; in group 5 the surfaces roughened with bur and silane applied; in group 6 the surfaces were etched with hydrofluoric acid and silane applied and in group 7 the surfaces were sandblasted and silane applied.

To all the above groups, metal orthodontic brackets were bonded with light cure adhesive. The brackets were later stored in artificial saliva and incubated at 37°C (24 hours). The samples were then subjected to shear bond strength test using an Instron universal testing machine. The debonded porcelain surfaces were then studied under stereomicroscope to assess site of bond failure.

Results

Sandblasting the ceramic surface and silane application showed the highest bond strength. Stereomicroscope examination after debonding showed that the bond failure is at bracket-adhesive interface in four groups namely hydrofluoric acid, sandblasting, hydrofluoric acid with silane and sandblasting with silane.

Conclusion

Sandblasting with silane combination produced the highest shear bond strength, so it is a clinically suitable method for bonding orthodontic metal brackets onto ceramic surface.

Clinical relevance

Bonding orthodontic brackets to ceramic crowns of patients has been a tough task. In this study, different conditioning methods were used to treat the ceramic surfaces before bonding. The results showed that sandblasting the ceramic surface prior to application of silane produced the highest shear bond strength which is clinically suitable to reduce bond failures.

How to cite this article

Girish PV, Dinesh U, Bhat CSR, Shetty PC. Comparison of Shear Bond Strength of Metal Brackets Bonded to Porcelain Surface using Different Surface Conditioning Methods: An in vitro Study. J Contemp Dent Pract 2012;13(4):487-493.
A Clinicopathological Study of Ossifying Fibromas and Comparison between Central and Peripheral Ossifying Fibromas
Authors: Hunasgi Santosh , Raghunath Vandana
Published: June 2013

Aims and objectives

To study the clinical, histological features of peripheral and central ossifying fibromas and also to compare between them.

Materials and methods

The sample comprised a total 50 cases of ossifying fibromas [25 central ossifying fibromas (COF) and 25 peripheral ossifying fibromas (POF)] inclusive of cemento-ossifying fibromas.

Results

The mean age is 28.2 years in POF and 24.7 years in COF. The male: female ratio was 1:1.5 in POF and 1:1.8 in COF. The size of the lesions varied from 0.45 to 2.75 cm in cases of POF and in COF, it ranged from 1.25 to 13.5 cm. COF showed more duration (1-8 years) when compared with POF (1-3). Majority of cases of COF showed radiolucent, mixed radiolucent and radiopaque unilocular lesions. The predominant cell type in both POF and COF was a combination of both ovoid and spindle cells. Regarding vascularity it showed mild, moderate and intense vascularity. On comparison of all stromal changes between POF and COF showed no statistically significant difference.

Conclusion

The clinical parameters and radiographic changes of POF and COF in our study were similar to the previous studies. Histopathological features like type of cells, cellularity and vascularity in POF and COF were similar to previous studies. However, when clinical and histopathological features were compared between POF and COF showed no statistical significance except for site of the lesion. These features signify the behavior of two lesions. Further research on larger sample might give more insights into these lesions.

How to cite this article

Hunasgi S, Raghunath V. A Clinicopathological Study of Ossifying Fibromas and Comparison between Central and Peripheral Ossifying Fibromas. J Contemp Dent Pract 2012;13(4):509-514.
A Comparative Evaluation of DIAGNOdent and Caries Detector Dye in Detection of Residual Caries in Prepared Cavities
Authors: Akbari Majid , Ahrari Farzaneh , Jafari Marzieh
Published: June 2013

Aim

The objective of this study was to determine the association between DIAGNOdent laser and caries detector dye in detection of the remaining caries in restorative cavities.

Materials and methods

The sample consisted of 100 cavities prepared in patients referring to the Department of Restorative Dentistry of Mashhad Dental School. After confirming caries absence by tactile examination, the presence of any residual caries was determined by a laser fluorescence (LF) device (DIAGNOdent Pen) and then by caries detector dye. The data were analyzed through McNemar test.

Results

When the cut off value was considered as ≥13, both DIAGNOdent Pen and caries detector dye found 54 cavities as without caries and 12 cavities as carious. There were 32 teeth diagnosed as decayed only by the dye and two cases that were diagnosed as having residual caries only by the DIAGNOdent. The McNemar test revealed a significant difference in the diagnosis of residual caries between the two methods (p < 0.05), as well as significant differences between each method and tactile examination (p < 0.05). When the cut off value was set at ≥25, no significant difference was found between laser fluorescence and tactile examination in residual caries detection (p > 0.05).

Conclusion

Both DIAGNOdent Pen and caries detector dye can be considered as adjuncts for detecting residual caries in prepared cavities. However, the use of laser fluorescence device can provide results that are more consistent with tactile examination, while relying on caries detector dye may result in excessive removal of tooth tissue, and thus increase the risk of pulpal exposure.

Clinical significance

Incomparision with caries detector dye, Residual caries detection by DIAGNOdent Pen is more consistent with tactile examination.

How to cite this article

Akbari M, Ahrari F, Jafari M. A Comparative Evaluation of DIAGNOdent and Caries Detector Dye in Detection of Residual Caries in Prepared Cavities. J Contemp Dent Pract 2012;13(4):515-520.
Association of Temporomandibular Joint Dysfunction, Condylar Position and Dental Malocclusions in Davangere Population
Authors: Girish KS , Savakkanavar Malthesh B , Sridhar S , Dinesh D , Ramesh GC
Published: June 2013

Aims:

• To study the association between dental malocclusions and temporomandibular joint dysfunction.

• To study the association between dental malocclusions and condylar position.

• To study the association between temporomandibular (TM) joint dysfunction and condylar position.

Methods

The subjects were divided into four groups for dental malocclusions viz. class I malocclusion with or without TM dysfunction, class II division 1 malocclusion with or without TM dysfunction, class II division 2 malocclusion with or without TM dysfunction and class III malocclusion with or without TM dysfunction. Once the patient fulfilled the criteria, the presence or absence of signs of TM dysfunction were elicited from the patient.

Results

It shows the association between TM dysfunction signs and left and right condylar positions. It shows the association between TM dysfunction symptom and left and right condylar positions. It shows the association between dental malocclusions and TM dysfunction signs and symptom. It shows the association between dental malocclusions and left and right condylar positions.

Conclusion

There was an association between TM dysfunction signs and left and right condylar positions. But, there was no association between TM dysfunction symptoms and left and right condylar positions. There was an association between dental malocclusions and TM dysfunction signs. But there was no association between dental malocclusions and TM dysfunction symptoms. There was an association between dental malocclusions and left condylar position, but there was no association between dental malocclusion and right condylar position.

Clinical significance

This study indicates that malocclusions and factors of condylar position should be seen as merely cofactors in the sense of one piece of the mosaic in the multifactorial problem of TM dysfunction. TM dysfunction factors that showed significant effects to various malocclusions through this study . This study shows clinical significance of association of various types of dental malocclusions to different conylar positions and TM dysfunction signs and symptoms. Before treating orthodontic patients, one should evaluate and treat the TM disorders for better prognosis.

How to cite this article

Malthesh B Savakkanavar, Sridhar S, Dinesh D, Girish KS, Ramesh GC. Association of Temporomandibular Joint Dysfunction, Condylar Position and Dental Malocclusions in Davangere Population. J Contemp Dent Pract 2012;13(4):528-533.