bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of Composite Shrinkage Stresses on 3D Premolar Models with Different Cavity Design Using Finite Element Method
Authors: Milosevic Milos , Mitrovic Nenad , Miletić Vesna , Tatic Uroš , Ezdenci Andrea
Published: September 2013

Local polymerization stress occurs due to polymerization shrinkage of resin based composites adhesively bonded to tooth tissues. Shrinkage causes local displacements of cavity walls, with possible occurrence of micro-cracks in the enamel, dentin and/or material itself. In order to design a cavity for experimental testing of polymerization shrinkage of dental composites using 3D optical analysis, in this paper finite element method (FEM) was used to analyze numerical models with different cavity radiuses. 3D optical strain and displacement analysis of composite materials and cavity walls is limited by equipment sensitivity i.e. 0.01% for strain and 1 micron for displacement. This paper presents the development of 3D computer premolar models with varying cavity radiuses, and local stress, strain and displacement analysis using FEM. Model verification was performed by comparing obtained results with data from the scientific literature. Using the FEM analysis of local strains, displacements and stresses exerted on cavity walls, it was concluded that the model with 1 mm radius was optimal for experimental optical 3D displacement analysis.
Temperature Influence on Microindentation Data of a Viscoelastic Material
Authors: Minster Jiří , Králík Vlastimil , Němeček Jiří
Published: September 2013

This paper aims to apply time-temperature superposition to short-term microindentation data measured at different temperatures, and to compare the viscoelastic compliance master curve that is found with data derived earlier from standard macro creep measurements in pressure. Using a sharp standard Berkovich indenter a successful application of this geometry in characterizing time-dependent mechanical properties of viscoelastic materials is confirmed.
Local Deformation of Microsized Amorphous Powder at Low Temperatures
Authors: Miškuf Jozef , Csach Kornel , Juríková Alena , Tabachnikova Elena D. , Bengus Vladimir Z.
Published: September 2013

The investigations of the failure characteristics of Fe76Ni2Si9B13 bulk amorphous alloys prepared by shock wave consolidation of powders were performed. The strength decreased with the lowering temperature from 300 to 4.2 K. For this temperature interval, the brittle failure prevails. The failure propagates across particles as well as along particle boundaries. The riverlike pattern with fine dimples was observed on the fracture surface. The apparent surface energy and the fracture toughness values estimated by means of the fractography were similar to these for typical brittle materials.
Investigation of Changes in Microstructure of Remelted Air Plasma Sprayed NiCrAlY Coating after Short Thermal Exposure in Air with the Assistance of Microhardness Measurements
Authors: Řičánková Veronika , Čelko Ladislav , Švejcar Jiří
Published: September 2013

The specimens in the present study were prepared by air plasma spraying of NiCrAlY coatings onto the INCONEL 713LC nickel-based superalloy substrate surface. Subsequently an aluminium sheet was cladded onto the coating surface by means of uniaxial cold pressing. After that the specimens were annealed at temperatures of 650, 850 and 1000°C for two hours in argon-flow atmosphere. The remelted NiCrAlY coating specimens were annealed at a temperature of 800°C for fifty hours in ambient atmosphere. A scanning electron microscope was used to record the changes in the modified coating microstructure. Chemical composition was measured by means of energy dispersive microanalysis. Qualitative and quantitative x-ray diffraction analysis was used for the final determination of phases. The microhardness of remelted air-plasma-sprayed NiCrAlY coatings before and after short thermal exposure was also measured.
Nanohardness of Individual Phases in WC – Co Cemented Carbides
Authors: Duszová Annamária , Halgaš Radoslav , Priputen Pavol , Bľanda Marek , Hvizdoš Pavol , Lofaj František , Dusza Ján
Published: September 2013

The nanohardness of WC – Co hardmetals has been investigated using instrumented indentation and Berkovich tip indenter. The nanohardness, HIT, and indentation modulus, EIT, of Co phase and individual WC grains and the influence of their crystalographic orientation have been studied. SEM, AFM and EBSD methods were used for the characterization of the microstructures and indents and for the identification of crystallographic orientation of WC grains, respectively. Strong indentation load-size effect and significant influence of the crystallographic orientation of WC crystals on HIT and EIT have been found. The nanohardness of Co binder was approximately 10 GPa and that of WC grains varied between 25 and 50 GPa, depending on the grain orientation and load. The nanohardness values of the basal and prismatic planes of individual WC grains at load of 10 mN were 40.4 ± 1.6 GPa and 32.8 ± 2.0 GPa, respectively.
Effect of Sterilization Processes on the Fiber/Matrix Interphase Properties of CF/PDMS Composite to be Used in Orthopaedics
Authors: Sedláček Radek , Suchy Tomas , Sochor Miroslav , Balik Karel , Sucharda Zbyněk , Šepitka Josef
Published: September 2013

In this study we present the investigation of the influence of multiple sterilization processes on micromechanical properties carried out on a composite based on carbon fibers (CF) and polymer matrix composite polydimethylsiloxane (PDMS). The effect of widely-used steam sterilization process on fibers/matrix interphase region properties was studied by nanoindentation.
Local Mechanical Properties of Cast and Sintered High Cr-Alloyed Steel
Authors: Shvab Ruslan , Hvizdoš Pavol , Dudrová Eva , Bergman Ola , Bengtsson Sven
Published: September 2013

Local mechanical properties of high Cr-alloyed sintered and cast steels with the same chemical composition were investigated using instrumented indentation method. Standard loading/unloading mode was applied, the measurements were done in load range 1 – 500 mN. Load size effect was observed and its parameters were evaluated. Indentation hardness and elastic modulus were found slightly higher for the sintered material. Differences in indentation parameters were explained based on microstructure of materials.
Characterization of the Interphase in Carbon Fiber Reinforced Polymeric Composite by a Modulus Mapping Test
Authors: Sucharda Zbyněk , Suchy Tomas , Sedláček Radek , Balik Karel , Šepitka Josef , Sochor Miroslav
Published: September 2013

The effect of sterilization on the structural integrity of the polydimethylsiloxane (PDMS) matrix composite reinforced with carbon fibers (CF) is investigated by nanoindentation test. We present the investigation of the influence of sterilization processes on fiber/matrix interphase properties. The effect of multiple widely-used steam sterilization processes on fibers/matrix interphase region properties was studied by modulus mapping test.
Verification of Numerical Model for Trabecular Tissue Using Compression Test and Time-Lapse X-Ray Radiography Based on Material Model Determined from Three-Point Bending Test of Single Trabecula
Authors: Zlámal Petr , Doktor Tomáš , Jiroušek Ondřej , Jandejsek Ivan
Published: September 2013

The aim of this study is to determine constitutive constants for elasto-plastic material model with damage for single trabecula based on the indirect simulation of micromechanical testing and its verification at macro level using compression test of the cylindrical sample of the trabecular tissue. Three-point bending test of isolated trabeculae was performed in a shielding box and deflection of the sample was acquired using X-ray microradiography. Measured values (displacements of markers) were used for indirect identification of the material model for single trabecula using finite element (FE) method. The bending test was simulated and results were fitted to experimentally obtained values and the appropriate set of material constants was determined. To verify the applicability of the identified material model the compression test of the complex sample was carried out. Cylindrical sample was incrementally loaded and each loading state was captured using the micro-computed tomography. Material model identified from three-point bending test was applied to the model of complex sample and the simulation of the compression test was performed.
Effect of Crystallographic Orientation on Hardness and Indentation Modulus in Austenitic Stainless Steel
Authors: Haušild Petr , Materna Aleš , Nohava Jiri
Published: September 2013

The most commonly used method for the analysis of instrumented indentation test (Oliver-Pharr) is based on isotropic elastic solution of contact problem which is not necessarily valid when indenting at the scale of one (anisotropic) grain. In this paper, we performed the grid indentation method at the sub-micron scale (at low indentation load and depth of penetration) on an area containing several grains with different crystallographic orientation which was simultaneously characterized by electron back-scattered diffraction. Measured dependencies of hardness and indentation modulus on crystallographic orientation were compared with analytical solution and finite element simulations.
Estimation of Local Plastic Deformation of Polycrystalline Materials
Authors: Martinkovič Maroš , Václav Stefan
Published: September 2013

Final properties of formed steel or another alloy pieces are affected even by plastic deformation of material. Therefore it is needful to know detail structure changes of material under conditions of plastic deformation caused by forming, grinding, drilling etc. Estimation of the deformation based on its observable macroscopic effects doesn’t correspond fully with microscopic structural changes in whole volume of deformed parts and such estimation is quite impossible in case if only surface layers are deformed. It is possible to obtain value of strain by measurement of grain boundary deformation. Effect of grains boundaries self-orientation caused by grains deformation can be identified on metallographic cut. Stereological measurement of degree of grain boundary orientation is relatively simple if axes of orientation are known (as it is in most of deformation processes). Preferred direction of grains boundaries orientation is the same as direction of deformation; however orientation is not the same thing as deformation. Therefore model of conversion of degree of grain boundary orientation to deformation based on an idealized shape of grains has been proposed. This conversion model is independent on an initial grain size – strain depends only on the shape of the grain and does not depend on its dimension. It allows experimental estimation of local plastic deformation by means of measurement of grain boundary orientation in various areas of plastically deformed parts.
Effect of Beta Irradiation on the Strength of Bonded Joints of HDPE
Authors: Bednarik Martin , Manas David , Ovsik Martin , Manas Miroslav , Stanek Michal , Sanda Stepan , Kratky Petr
Published: September 2013

At the present time bonding has spread into almost all sectors of practice and it would be very difficult to find an industry in which there is no need to use this technology of joining a wide range of materials. In comparison with conventional joining methods (riveting, welding and screwing) provides bonding new combination of options and allows obtaining special shapes and properties which cannot be created by conventional methods of coupling. For the formation of quality bonded joint it is important that the adhesive bonding surface is well wetting. Wettability is characterized by the contact angle of wetting. The liquid must have a lower surface tension than the solid in order to be able to wetting the solid substance. This article describes the effect of beta irradiation on the contact angle of wetting, on the surface energy and on the final strength of bonded joints of HDPE.
Mechanical Properties of Metal Matrix Nanocomposites Synthesized by Selective Laser Melting Measured by Depth Sensing Indentation Technique
Authors: Biedunkiewicz Anna , Figiel Pawel , Biedunkiewicz Witold , Dariusz Grzesiak , Krawczyk Marta , Gabriel-Polrolniczak Urszula
Published: September 2013

This work presents an investigation of basic mechanical properties (hardness, Young modulus) of metal matrix composites (MMC) reinforced with non-oxide ceramic nanoparticles by means of nanoindentation measurements. The evaluated materials were manufactured by selective laser melting (SLS/M). As a matrix 316L stainless steel and as a reinforcing phase TiC nanoparticles were used. The influence of nanoscale reinforcement on the mechanical properties of MMC manufacturing with SLS/M process was examined. In this case statistical evaluation of hardness and Young modulus based on nanoindentation data was performed.
Local Mechanical Properties of Au Thin Films on Polyethylene
Authors: Bláhová Olga , Bublíková Petra , Slepička Petr , Švorčík Václav
Published: September 2013

Mechanical properties and surface morphology of metallized and grafted PE samples were studied upon their surface modification (plasma exposure and grafting) and subsequent metallization (Au sputtering).
Digital Image Correlation Based Method of Crack Growth Rate and Fracture Toughness Measurements on Mini-Samples
Authors: Brynk Tomasz , Laptiev Anatolii , Tolochyn Oleksandr , Pakiela Zbigniew
Published: September 2013

Modern materials fabrication methods which utilize severe plastic deformation (SPD) do not often allow to obtain enough volume of material to prepare standardized samples for mechanical tests. Therefore, there is a need for mini-samples testing. Mini-samples tests require special approach in terms of precise strain measurements. Accurate strain measurements may be achieved by means of non-contact optical method, namely Digital Image Correlation (DIC). The aim of this work is to present the methodology and results of mini-samples tests in which displacement fields measurements performed by means of DIC and inverse method were utilized for calculation of stress intensity factors and crack tip position tracking. The influence of the subarea of optical measurements for which calculation were performed on the calculations results has been investigated during tests in SPD processed Al alloys and brittle WC-Co sinters produced by means of impact sintering method.
SCREENING OF HEPATITIS G AND EPSTEIN-BARR VIRUSES AMONG VOLUNTARY NON REMUNERATED BLOOD DONORS (VNRBD) IN BURKINA FASO, WEST AFRICA
Authors: Tao Issouf , Bisseye Cyrille , Nagalo Bolni Marius , Sanou Mahamoudou , Kiba Alice , Surat Guzin , Compaore Tegwinde Rebecca , Traore Lassina , Yonli Albert , Nikiema Jean-Baptiste , Zongo Jean-Didier , Simpore Jacques
Published: September 2013

In most sub-Saharan countries screening of blood-transmitted infections includes mainly HIV, HBV, HCV and syphilis. Many viruses such as Hepatitis G (HGV) and Epstein-Barr virus (EBV) which also carry a risk of transmission by blood transfusion raise the question of the extent of screening for these pathogens. This work aims to evaluate the prevalence of HGV and EBV in first-time blood donors in Ouagadougou. The prevalence of HGV and EBV in 551 blood donors was 7.4% and 5.4% respectively. HGV prevalence was significantly higher in blood donors with hepatitis B antigens and positive for HCV compared to donors negative for HCV and no hepatitis B antigens (respectively p<0.001 and p=0.004). EBV prevalence was higher among blood donors of < 20 years age group. This study shows significant results with regard to the prevalence of HGV and EBV prevalence in blood donors in Burkina Faso and emphasizes the need for a general screening.
BETA-GLOBIN GENE MUTATIONS IN TURKISH CHILDREN WITH BETA-THALASSEMIA: RESULTS FROM A SINGLE CENTER STUDY
Authors: Fettah Ali , Bayram Cengiz , Yarali Nese , Isik Pamir , Kara Abdurrahman , Culha Vildan , Tunc Bahattin
Published: September 2013

Introduction: The beta thalassemias are common genetic disorders in Turkey and in this retrospective study our aim was to evaluate β-globin chain mutations and the phenotypic severity of β-thalassemia patients followed-up in our hospital, a tertiary center which serves patients from all regions of Turkey. Materials and Methods: 106 pediatric patients were analysed for β-globin gene mutations by using DNA analysis. Patients were classified as having β-thalassemia major or β-thalassemia intermedia based on age at diagnosis, transfusion frequency and lowest hemoglobin concentration in between transfusions. Results: There were 106 patients (52.8% female and 47.2% male) with a mean age of 11.2±5 years (1.6 – 22.3 years). Eighty-four (79.2%) patients had β-thalassemia major, whereas the remaining 22 patients (20.8%) were identified as having β-thalassemia intermedia. Overall, 18 different mutations were detected on 212 alleles. The most frequently encountered mutation was IVS I.110 (G>A) (35.3%), followed by Codon 8 del-AA (10.4%), IVS II.1 (G>A) (8%), IVS I.1 (G>A) (7.5%), Codon 39 (C>T) (7.1%) and Codon 5 (-CT) (6.6%), which made up 79.4% of observed mutations. According to present results, IVS I.110 (G>AA) was the most frequent mutation observed in this study, as in other results from Turkey. Evaluation of β-thalassemia mutations in 106 patients with 212 alleles, revealed the presence of homozygous mutation in 85 patients (80.2%) and compound heterozygous mutation in 21 patients (19.8%). The mutations detected in patients with homozygous mutation were IVS I.110 (G>A) (38.8%), Codon 8 del –AA (11.8%), IVS II.1 (G>A) (8.2%) and IVS I.1 (G>A) (8.2%). Observed mutations in the compound heterozygotes were Codon 39 (C>T)/Codon 41-42 (-CTTT) (14.3%), IVS I.110 (G>A)/Codon 39(C>T) (14.3%), IVS I.110 (G>A)/Codon 44(-C) (14.3%), and IVS II.745 (C>G)/ 5’UTR + 22 (G>A) (9.5%). Conclusion: Our hospital is a tertiary referral center that provides care to patients from all over the country, and thus the distribution of mutations observed in the current study is significant in term of representing that of the country as a whole.
VITAMIN D STATUS IN THALASSEMIA MAJOR: AN UPDATE
Authors: Soliman Ashraf Tawfik
Published: September 2013

The survival of patients with thalassemia major has progressively improved with advances in therapy; however, osteoporosis and cardiac dysfunction remain frequent complications. Adequate circulating levels of vitamin D are essential for optimal skeletal health and reducing fracture risk. Vitamin D deficiency and insufficiency is reported to be high in thalassemic patients in many countries despite the presence of good sunshine and routine prescription of 400–1,000 IU vitamin D per day. The risk of vitamin D deficiency in thalassemia and its relation to bone disease; including osteoporosis, rickets, scoliosis, spinal deformities and fractures as well as to cardiac dysfunction is discussed in this mini-review. Monitoring and maintaining normal serum level of 25-OH vitamin D through oral intake of vitamin D and early correction of VDD by oral or parental use of vitamin D may significantly improve bone mineral accretion and ameliorate cardiac function. The survival of patients with thalassemia major has progressively improved with advances in therapy; however, osteoporosis and cardiac dysfunction remain frequent complications. Adequate circulating levels of vitamin D are essential for optimal skeletal health and reducing fracture risk. Vitamin D deficiency and insufficiency is reported to be high in thalassemic patients in many countries despite the presence of good sunshine and routine prescription of 400–1,000 IU vitamin D per day. The risk of vitamin D deficiency in thalassemia and its relation to bone disease; including osteoporosis, rickets, scoliosis, spinal deformities and fractures as well as to cardiac dysfunction is discussed in this mini-review. Monitoring and maintaining normal serum level of 25-OH vitamin D through oral intake of vitamin D and early correction of VDD by oral or parental use of vitamin D may significantly improve bone mineral accretion and ameliorate cardiac function.
Sexual and reproductive health needs assessment with deaf people in Ghana: Methodological challenges and ethical concerns
Authors: Mprah Wisdom K.
Published: September 2013

Background: Deafness is a complex and multifaceted phenomenon. The different ways of perceiving and understanding deafness have practical implications for research with deaf people. Whilst the deaf community is not homogenous, it is generally distinct from the hearing population. Consequently, the appropriateness of applying research methods and informed concern processes designed for the hearing population in research with deaf people has been questioned.Objectives: This article reflected on some methodological challenges and ethical concerns arising from conducting a sexual and reproductive health needs assessment with deaf people in Ghana. The aim was to provide some perspectives on some of the challenges associated with doing research with deaf people.Method: The study was a two phase, sequential, mixed methods design, consisting of three focus groups to assist in the development of a survey and then the implementation of the survey for needs assessment data collection. The number of participants in the study was 179, consisting of 26 focus group participants: 7 executives of the Ghana National Association of the Deaf (GNAD), 10 male adults, and 9 female adults. There were 152 survey respondents (students, women and men) and one key informant. All participants, except the key informant, were deaf people.Results: The application of traditional research methods to studies involving deaf participants presents numerous methodological and ethical dilemmas associated mainly with deaf people’s unique cultural and linguistic characteristics.Conclusion: Research methods should not be taken as universal guidelines for conducting research in all settings because of differences in settings.
Assessing medical students’ competence in calculating drug doses
Authors: Harries Catherine , Botha Julia
Published: September 2013

Evidence suggests that healthcare professionals are not optimally able to calculate medicine doses and various strategies have been employed to improve these skills. In this study, the performance of third and fourth year medical students was assessed and the success of various educational interventions investigated. Students were given four types of dosing calculations typical of those required in an emergency setting. Full competence (at the 100% level) was defined as correctly answering all four categories of calculation at any one time. Three categories correct meant competence at the 75% level. Interventions comprised an assignment with a model answer for self-assessment in the third year and a small group tutorial in the fourth year. The small groups provided opportunities for peer-assisted learning. A subgroup of 23 students received individual tuition from the lecturer prior to the start of the fourth year. Amongst the 364 eligible students, full competence rose from 23% at the beginning of the third year to 66% by the end of the fourth year. More students succeeded during the fourth than the third year of study. Success of small group tuition was assessed in a sample of 200 students who had formal assessments both before and after the fourth year tuition. Competence at the 75% level improved by 10% in attendees and decreased by 3% in non-attendees, providing evidence of the value of students receiving assistance from more able same-language peers. Good results were achieved with one-on-one tuition where individualised assistance allowed even struggling students to improve.
The Evaluation of Two Commercially Available, Portable Raman Systems
Authors: Mosier-Boss Pamela A. , Putnam Michael D.
Published: September 2013

Raman spectroscopy and surface enhanced Raman spectroscopy (SERS) have many attributes that make them attractive for field detection of environmental contaminants, industrial process control, as well as materials detection/identification in agriculture, pharmaceuticals, law enforcement/first responders, geology, and archeology. However, portable, robust, inexpensive Raman systems are required for these applications. In this communication, the performances of two commercially available, portable Raman systems are evaluated.
CO451 corn inbred line
Authors: Reid L. M. , Zhu X. , Voloaca C. , Wu J. , Woldemariam T.
Published: September 2013

Reid, L. M., Zhu, X., Voloaca, C., Wu, J. and Woldemariam, T. 2014. CO451 corn inbred line. Can. J. Plant Sci. 94: 169–173. CO451 is a short-season corn (Zea mays L.) inbred line with excellent combining ability as well as moderate resistance to common smut and fusaruim stalk rot. Excellent hybrid yields and performance data were achieved when CO451 was combined with stiff stalk inbreds such as MBS1130 and MBS9250 as well as with the Iodent inbred MBS8148.
Mercury Hygiene Practices followed in Dental Clinics in Pune: A Survey
Authors: Raghavendra Srinidhi Surya , Ranadive Nishita
Published: September 2013

Introduction

Amalgam has proved to be among the most versatile and durable of all restorative materials. Mercury in various forms has been found to be toxic. Dental personnel can be exposed to mercury in myriad ways like direct skin contact or exposure to mercury vapors through spillage or during various steps of restoration. Proper storage and recycling of waste amalgam has been a challenge. Waste amalgam and spent capsules may be disposed of in the general office refuse and they later enter municipal dumps or incinerators.

Along with the need for amalgam recycling, the knowledge of the dentists about the deleterious effects, method of handling, effective storage and efficient disposal of amalgam scrap is vital. It was felt that the method used by the third party agency for disposing amalgam scrap should be mentioned.

Materials and methods

A confidential questionnaire was formed of close- and open-ended questions regarding the awareness of toxic effects of mercury, its handling and storage prior to disposal. This was distributed randomly to 100 private practitioners in Pune city, Maharashtra state, India. A response rate of 75% was obtained. The results were analyzed.

Results

All the dentists surveyed were aware of the toxic effects of mercury. Thirty-four percent were storing the scrap in the ADA-recommended method, 23% were replacing more than 5 to 10 amalgam restorations with esthetic alternatives per week, 32% used high volume evacuation while removing old fillings and 94% of them had evacuation into the common drain without any recapture systems.

Conclusion

We need to develop a comprehensive waste management plan for the disposal of amalgam scrap. Guidelines need to be established not only among the dentists but also with the waste disposal agency. This will go a long way in reducing the deleterious effects of mercury in the environment.

How to cite this article

Srinidhi SR, Ranadive N. Mercury Hygiene Practices followed in Dental Clinics in Pune: A Survey. World J Dent 2013;4(2):92-95.
Central Neurilemmoma of Mandible
Authors: Bagewadi Anjana , Keluskar Vaishali , Byakodi Raghavendra , Shetti Arvind
Published: September 2013

Neurilemmomas involving bones are rare tumors constituting less than 1% of central benign tumors of bone. Only few cases of neurilemmomas occurring in the mandible have been reported in the medical literature so far. Here, we report a case of neurilemmoma involving the posterior aspect of mandible in a 15 years old male child. This case was a diagnostic challenge as the clinical features and radiographic features mimicked that of an odontogenic cyst but histologically turned out to be a neurilemmoma. Discussion on the incidence, clinical presentation, radiographic appearance, histopathological features and treatment of this benign neurogenic tumor is presented here.

How to cite this article

Byakodi R, Keluskar V, Bagewadi A, Shetti A. Central Neurilemmoma of Mandible. World J Dent 2013;4(2):134-137.
Outcome of Laparoscopic Ovarian Drilling in Patients of Clomiphene Resistant Polycystic Ovarian Syndrome in a Tertiary Care Center
Authors: Shashikala T , Kaur Mandeep , Pranesh Gautham , Gahlan Anjali , Deepika K
Published: September 2013

Background

Polycystic ovarian syndrome (PCOS) is the most common endocrine disorder in women and its prevalence is rising. Management of the disease is usually medical and some resistant cases may require surgical treatment in the form of laparoscopic ovarian drilling (LOD). Medical management exposes the patient to increased risk of multiple pregnancy and hyperstimulation. LOD avoids the need of medical therapy or makes the ovaries more responsive to treatment.

Aim

The objective of this descriptive study was to study the outcome of LOD in patients of PCOS with clomiphene resistance in the form of clinical pregnancy and live birth rate.

Setting

Tertiary assisted conception center.

Design

Observational study.

Materials and methods

100 patients of clomiphene resistant PCOS who underwent LOD.

Outcome measure

Primary outcome was clinical pregnancy rate and secondary outcome was ovarian hyperstimulation syndrome (OHSS) rate, multiple pregnancy rate, miscarriage rate, prevalence of hypothyroidism and live birth rate in PCOS patients.

Results

Clinical pregnancy rate—47.3%, OHSS rate—2.7%, multiple pregnancy rate—4%, miscarriage rate—6.7%, prevalence of hypothyroidism—48% and live birth rate—40.5%.

Conclusion

Patients with irregular cycles, high LH/FSH ratio usually have CC resistance. PCO patients have high prevalence of hypothyroidism and it should be specifically screened and treated. Low incidence of miscarriage rate, OHSS rate and multiple pregnancy rates is seen after LOD with 47.3% clinical pregnancy and 40.5% live birth rates. Patients with high values of LH/FSH ratio are the candidates who stay nonpregnant in spite of LOD and this information is very useful in prognosticating the patients.

How to cite this article

Kaur M, Pranesh G, Mittal M, Gahlan A, Deepika K, Shashikala T, Rao KA. Outcome of Laparoscopic Ovarian Drilling in Patients of Clomiphene Resistant Polycystic Ovarian Syndrome in a Tertiary Care Center. Int J Infertility Fetal Med 2013;4(2):39-44.
In vitro Evaluation of the Minimum Bactericidal Concentrations of Different Root-End Filling Materials
Authors: Koçak Mustafa Murat , Oktay Elif Aybala , Kiliç Abdullah , Yaman Sis Darendeliler
Published: September 2013

Aim

The aim of this study was to evaluate the minimum bactericidal concentrations (MBC) of root-end filling materials ProRoot MTA, MTA Angelus and IRM.

Materials and methods

Macrodilution broth method was used. Microorganisms used were: Staphylococcus aureus (ATCC 29213), Enterococcus faecalis (ATCC 29212) and Streptococcus mutans. Serial two-fold dilutions of root-end filling samples were prepared in macrodilution tubes with concentrations ranging from 1/2 to 1/512. The samples dilutions were incubated for 24 hours. After incubation, 0.1 ml of diluted culture was inoculated onto the surface of supplemented sheep blood agar (Merck, Germany) and all plates were incubated at 37°C in aerobic condition for 24 hours. The MBC was defined as the lowest concentration of root-end filling samples where no growth was recorded.

Results

MBC of both mineral trioxide aggregate (MTA) products against S. aureus were recorded as 15.62 mg/ml and for IRM 31.25 mg/ml MBC for both MTA groups against E. faecalis were recorded as 31.25 mg/ml and for IRM 62.5 mg/ml. MBC of all root-end filling samples against S. mutans were recorded as 62.5 mg/ml.

Conclusion

All tested root-end filling materials showed acceptable MBC against S. aureus and E. faecalis.

Clinical significance

All tested materials can be used safely for filling of a root-end cavity.

How to cite this article

Koçak MM, Koçak S, Oktay EA, Kiliç A, Yaman SD. In vitro Evaluation of the Minimum Bactericidal Concentrations of Different Root-End Filling Materials. J Contemp Dent Pract 2013;14(3):371-374.
Comparison of Antibacterial Activity of Glass-ionomer Cement and Amalgam in Class Two Restorations by Streptococcus mutans Count Analysis at Fixed Intervals: An in vivo Study
Authors: Tegginmani Veeresh S , Goel Beenarani , Uppin Virendra , Kumar LS Vijay , Nainani Abhinav
Published: September 2013

Aim

The purpose of the present study was to determine the influence of glass ionomer cement and amalgam restoration on the level of Streptococcus mutans in the interproximal plaque at periodic intervals and also to compare these values.

Materials and methods

Seventeen adult patients having two proximal carious lesions on any quadrant of the jaw (either opposing or contralateral) were selected for this study. Carious lesions were diagnosed clinically and from bitewing radiographs. Of the two carious lesions, one was restored with glass ionomer cermet cement and another with amalgam. Plaque samples were collected from interproximal areas before and at 1 month and 3 months post-treatment in a test tube containing 5 ml of modified Stuart's liquid transport fluid. Identification of organisms in the colony was done after Gram staining.

Results

Comparison of values before restoration and after restoration at 1 month interval showed a statistically significant decrease (p < 0.001). Similarly, comparison of values before and after restorations at 3 months also showed statistically significant decrease (p < 0.02). But comparison of restorations of 1 and 3 months intervals showed no statistical significant difference (p > 0.05).

Conclusion

Glass ionomer restorations have definite advantage over the amalgam, as the tunnel preparation is more conservative and fluoride release from the glass ionomer inhibits the growth of S. mutans in the plaque.

Clinical significance

Glass ionomer cement should be preferred over amalgam in conservatively prepared restorations as it reduces the microbial activities due to fluoride release.

How to cite this article

Tegginmani VS, Goel B, Uppin V, Horatti P, Kumar LSV, Nainani A. Comparison of Antibacterial Activity of Glass-ionomer Cement and Amalgam in Class Two Restorations by Streptococcus mutans Count Analysis at Fixed Intervals: An in vivo Study. J Contemp Dent Pract 2013;14(3):381-386.
Potential Effect of Neutrophil Functional Disorders on Pathogenesis of Aggressive Periodontitis
Authors: Tapashetti Roopali P , Sharma Sumit , Guvva Sowjanaya
Published: September 2013

Introduction

Leukocytes play a key role in maintaining the balance between an effective host defence response to microorganisms and periodontal tissue destruction. Neutrophil dysfunction has been associated with increased susceptibility to periodontal diseases. We undertook this study to determine to what extent neutrophil dysfunction constitutes to the pathogenesis of aggressive periodontitis (AgP) in tropical country like ours.

Materials and methods

Age- and sex-matched groups consisting of 20 subjects each of generalized aggressive periodontitis (GAP)–cases and nonperiodontitis (NP)–controls. diabetes mellitus, HIV infection, prolonged antibiotic use and smoking were excluded.

Each neutrophil function was assessed using the chemotactic assay using case in, phagocytosis assay, candidacidal assay (for intracellular killing) and NBT assay (for respiratory burst failure).

Statistical analysis used

Student's t-test, Fisher's exact test and Chi-square test.

Results

In the study 17 out of 20 subjects (85%) had at least one abnormal neutrophil assay either hypofunctional or hyperfunctional of which 16 (80%) had hypofunctional assays and 8 (40%) had hyperfunctional assays. Defective phagocytosis was the commonest (50%) followed by chemotactic defect (45%), defective respiratory burst (40%) and defective intracellular killing (30%). Mean of chemotaxis assay was significantly less in AgP when compared to controls (103 vs 129 £gm, p = 0.002), similarly for phagocytic defect (3.45 vs 4.65, p „T 0.001) and with candidacidal assay (26.80 vs 37.35, p < 0.001).

Conclusion

The prevalence of neutrophil dysfunction, predominantly hypofunctional, was significantly very high in GAP patients with few even having hyperactive respiratory burst function. Multiple level neutrophil defects could account for the aggressive nature of AgP even in apparently healthy subjects.

How to cite this article

Tapashetti RP, Sharma S, Patil SR, Guvva S. Potential Effect of Neutrophil Functional Disorders on Pathogenesis of Aggressive Periodontitis. J Contemp Dent Pract 2013;14(3):387-393.
Comparison of Rate of Canine Retraction into Recent Extraction Site with and without Gingival Fiberotomy: A Clinical Study
Authors: Kalra Amit , Jaggi Nitin , Bansal Manu , Goel Sumant , Medsinge Sonali V , Abraham Reji , Jasoria Gaurav
Published: September 2013

Aim

Retraction of maxillary canines after first premolar extractions is a very common orthodontic task in cases of crowding or for the correction of large overjet. Many studies have been done to increase the rate of retraction. The aim is to compare the rate of canine retraction into recent extraction site with and without circumferential supracrestal fiberotomy.

Materials and methods

The rate of movement of the canines into the recent extraction site of the first premolar with or without circumferential supracrestal fiberotomy was measured in 14 patients aged 13 to 22 years. The study was done on 9 maxillary and 5 mandibular arches. The appliance used in the present study was the preadjusted edgewise (0.022 inch Roth prescription) and retraction performed by frictionless mechanics using Composite T Loop. The distalization of canines was measured at regular intervals (T1, T2, T3 and T4). Recordings of the positions of the canines at the beginning and at different intervals were made from dental casts.

Results

The mean difference between the two sides for the total time span T1-T4, for maxillary arch was 0.36 mm and for mandibular arch was 0.60 mm respectively.

Conclusion

There can be various factors that affect the rate of tooth movement. Factors like bone density, bone metabolism, and turnover in the periodontal ligament, amount of force applied may be responsible for the variation.

Clinical significance

No clinically significant increased rate of retraction of cuspids in the recent extraction site with fiberotomy was found in comparison to the retraction in recent extraction site without fiberotomy.

How to cite this article

Kalra A, Jaggi N, Bansal M, Goel S, Medsinge SV, Abraham R, Jasoria G. Comparison of Rate of Canine Retraction into Recent Extraction Site with and without Gingival Fiberotomy: A Clinical Study. J Contemp Dent Pract 2013;14(3):419-426.
Prevalence of Tobacco Habits and Attitude toward Its Cessation among Outpatients of Mahatma Gandhi Mission's Dental College and Hospital, Navi Mumbai, Maharashtra
Authors: Hussain Juveria Syed Ali
Published: September 2013

Background

Information regarding the tobacco habits in patients visiting Mahatma Gandhi Mission's (MGM) Dental College and Hospital is scarce. Therefore, development and better implementation of the tobacco cessation initiatives can be undertaken with the knowledge of the tobacco use among patients.

Materials and Methods

A cross-sectional, questionnairebased study was conducted among the outpatients of MGM Dental College and Hospital from July to September, 2012. Questions regarding the form of tobacco used, frequency, duration and attitude toward stopping its consumption were asked. Statistical analysis was carried out using descriptive statistics and chi-square tests using Statistical Software package (SPSS) version 17.

Results

314/505 (62.1%) of the patients reported of tobacco use. Majority 162/314 (51.6%) of the patients used smokeless tobacco in which mishri and gutkha were mostly consumed. Work pressure was the common 100/314 (31.8%) cause of tobacco use. More than half the patients had tried to quit the habit and showed awareness toward its adverse effects on oral and general health.

Conclusion

Tobacco use has become an important concern due to its growing addiction among all age groups and gender. It is imperative to understand the psychosocial ideology and pattern of tobacco use among the patients in order to effectively counsel and motivate them to stop the habit.

How to cite this article

Hussain JSA, Ram SM. Prevalence of Tobacco Habits and Attitude toward Its Cessation among Outpatients of Mahatma Gandhi Mission's Dental College and Hospital, Navi Mumbai, Maharashtra. J Contemp Dent 2013; 3(2):57-60.
Oral Cancer: The Dentist's Intervention
Authors: Dekate Kamlesh , Kumar Shwetha , Haque Nasreen
Published: September 2013

Prevention and early detection are fundamental tools in the control of the oral cancer. Until recently screening and early detection of oral cancer has been dependent on a complete visual examination. Since simple examination is subject to observer variability adjunctive screening aids have been introduced to aid in early detection of oral cancer. The present paper outlines a brief overview of techniques in improving the identification of potentially malignant changes of the oral mucosa. We conclude that further research with clear objectives is strongly required to optimize and validate these oral screening procedures.

How to cite this article

Kumar S, Dekate K, Patel S, Haque N. Oral Cancer: The Dentist's Intervention. J Contemp Dent 2013; 3(2):74-77.
Infection Control Policy for Dental Practice: An Evidence-based Approach
Authors: Jawdekar Ashwin Muralidhar
Published: September 2013

Having a policy on infection control based on current evidence and guidelines is essential for all dental practices. The evidence shows that all the members of the dental team may not possess adequate knowledge of all relevant aspects related to infection control, such as the transmission of infectious diseases, current regulations, etc. Moreover, there exists evidence to support the value of education and certified training the dental professionals in improving their understanding of infection control policies and procedures. The training must be provided by an expert team comprising of an academician with suitable clinical experience and demonstrable expertize in dentistry, and a microbiologist who understands the needs of dental settings. Evidence suggests that a training over 10 hours is associated with maximal benefits; and the CDC and BDA guidelines recommend training to all dental staff (clinical as well as nonclinical) for optimal benefits. Successful implementation of the infection control policies depends on the adequate provision of time and facilities for the same.

How to cite this article

Jawdekar AM. Infection Control Policy for Dental Practice: An Evidence-based Approach. J Contemp Dent 2013;3(2):82-86.
Reinstating Buccally Flared Molars using a Modified Transpalatal Arch
Authors: Sonawane Manish Suresh , Karandikar Girish Ramchandra , Pawar Priyanka Anil , Shah Shaili Sanjay
Published: September 2013

Countless efforts have been made to correct scissors bite, intermaxillary cross elastics being the most conventional one. These generate extrusive forces on both upper and lower molars, thus opening the bite with consequent clockwise rotation of the mandible. Also, treatment results depend largely on patient cooperation.

Of late, microimplants have gained tremendous popularity in the treatment of such malocclusions because of their reliability and predictability. But, it carries surgical risks, requires more clinical time and cost.

The critical procedures for scissors bite correction are intruding and palatally tipping the involved tooth when it is both extruded and buccally flared. We have designed a modified transpalatal arch (M-TPA) to achieve both with minimal side effects. Advantages are quick and easy chairside fabrication and adjustment, no patient compliance required, no complicated laboratory procedure involved and is cost-effective. Moreover, the arms can be oriented distal or mesial to the M-TPA depending on the involved teeth.

How to cite this article

Sonawane MS, Karandikar GR, Pawar PA, Shah SS. Reinstating Buccally Flared Molars using a Modified Transpalatal Arch. J Contemp Dent 2013;3(2):98-101.
Minimally Invasive Approach to Restore Anterior Spaces with Porcelain Laminate Veneers
Authors: Mhaske Prasad Nanasaheb , Nadgere Jyoti B
Published: September 2013

Restoring anterior teeth is a big challenge for dentists today because of the esthetic concerns and also the patient's expectation for a natural looking smile. An unpleasant smile traumatizes the patient psychologically as it decreases their confidence and is a cause for social embarrassment. This case describes a patient who reported with a complaint of open spaces in maxillary anterior teeth, desiring enhancement of esthetics and was treated successfully with porcelain laminate veneers. Very minimal tooth preparation was carried out on the labial aspect of the maxillary incisors and canines, keeping in mind the minimally invasive approach. Veneers were fabricated using lithium disilicate ceramics and were bonded to the tooth surface using adhesive resin cement.

How to cite this article

Mhaske PN, Ram SM, Shah N, Nadgere JB. Minimally Invasive Approach to Restore Anterior Spaces with Porcelain Laminate Veneers. J Contemp Dent 2013;3(2):108-111.
Size-resolved aerosol composition and link to hygroscopicity at a forested site in Colorado
Authors: Levin E. J. T. , Prenni A. J. , Palm B. , Day D. , Campuzano-Jost P. , Winkler P. M. , Kreidenweis S. M. , DeMott P. J. , Jimenez J. , Smith J. N.
Published: September 2013

Abstract. Aerosol hygroscopicity describes the ability of a particle to take up water and form a cloud droplet. Modeling studies have shown sensitivity of precipitation-producing cloud systems to the availability of aerosol particles capable of serving as cloud condensation nuclei (CCN), and hygroscopicity is a key parameter controlling the number of available CCN. Continental aerosol is typically assumed to have a representative hygroscopicity parameter, κ, of 0.3; however, in remote locations this value can be lower due to relatively large mass fractions of organic components. To further our understanding of aerosol properties in remote areas, we measured size-resolved aerosol chemical composition and hygroscopicity in a forested, mountainous site in Colorado during the six-week BEACHON-RoMBAS campaign. This campaign followed a year-long measurement period at this site, and results from the intensive campaign shed light on the previously reported seasonal cycle in aerosol hygroscopicity. New particle formation events were observed routinely at this site and nucleation mode composition measurements indicated that the newly formed particles were predominantly organic. These events likely contribute to the dominance of organic species at smaller sizes, where aerosol organic mass fractions of non-refractory components were between 70–90%. Corresponding aerosol hygroscopicity was observed to range from κ = 0.15–0.22, with hygroscopicity increasing with particle size. Aerosol chemical composition measured by an Aerosol Mass Spectrometer and calculated from hygroscopicity measurements agreed very well during the intensive study with an assumed value of κorg = 0.13 resulting in the best agreement.