1,720,955 research outputs found
L'anatomia endodontica dei secondi molari superiori: ricerca ex vivo
No full textAim: of the present study was to deter- mine anatomic complexities which can be seen in maxillary second molars, with a specific attention to the presence of MB2 (second mesio-buccal) canals. Methodology: 50 maxillary second molars, which had been extracted for periodontal reasons, were selected for the study, following strict exclusion cri- teria. After determining the different roots, only the mesio-buccal one was examined. Location and number of canals were determined (i) after a normal access cavity, (ii) after a wider removal of dentine from the chamber floor, and (iii) after sectioning the root 4 mm be- low the cementum-enamel junction. Data were collected and analyzed. Results: MB2 canals were present in 44% of the examined teeth (20% of ca- ses showed Weine 2 configuration, while the remaining 24% showed Weine 3 configuration). It was possible to estabilish patency in MB2 canals only in 28% of cases.
Conclusions: MB2 canals are often present in maxillary second molars, being individuated in nearly half cases. This possibility and the presence of an indipendent apex make the research of MB2 canals mandatory during the endodontic treatment
Valutazione comparativa in vitro di un nuovo plugger per il System B
Full text linkA i m: t h e c o n t i n u o u s w a v e o f o b t u r a t i o n t e c h - nique requires adequate canal enlargement to insert the smallest Buchanan plugger (fine 50/06) to the ideal length, in order to prop- erly compact guttapercha in the root canal sys- tem. Due to the introduction of a new small- er plugger (30/04) shaping and obturation procedures are expected to be easier. The aim of the study was to evaluate in vitro how deep apically the new plugger penetrates and com- pare penetration with the “fine” plugger.
Me t h o d o l o g y : t w o t e s t s w e r e c a r r i e d o u t , o n 10 extracted molars and on 5 mesial roots of lower molars, respectively. All canals were shaped up to apical diameter of 25 and .06 ta- p e r. I n t h e f i r s t t e s t , t h e n e w p l u g g e r w a s i n - serted as deep as possible. In the second test, initially two 30/04 pluggers and then two 50/06 pluggers were inserted in the mesial canals as deep as clinically required. Radi- ograms were taken of all samples by means of a millimetric grid. Pictures were scanned, and digitally analized.
R e s u l t s : t h e f i r s t t e s t s h o w e d t h a t t h e me a n maximum depth reached by 30/04 pluggers is 1.35 mm shorter from the root canal radi- ographic terminus; in the second test 30/04 pluggers showed mean penetration values sig- nificantly deeper than those reached by 50/06 pluggers.
C o n c l u s i o n s : t h e n e w 3 0/ 0 4 p l u g g e r – w hi c h is smaller and more flexible than the 50/06 one – can easily be inserted up to 2 mm from the root canal apex without removing large amounts of dentin
Trasporto del forame apicale durante la sagomatura con gli strumenti rotanti K3endo: studio sperimentale in vitro
No full textGli strumenti in Nichel Titanio di ultima generazione consentono una sagomatura rapida ed efficiente del sistema dei canali radicolari ma alcuni dubbi rimangono riguardo alla possibilità che, soprattutto nei diametri maggiori, inducano stiramenti del forame apicale. Scopo di questo lavoro è quello di verificare l’azione dei K3endo sul forame apicale.
Materiali e metodi: Il forame apicale di 12 elementi dentari monoradicolati è stato fotografato allo stereomicroscopio prima e dopo la sagomatura con strumenti rotanti K3endo. I risultati sono stati registrati ed analizzati.
Conclusioni: l’utilizzo degli strumenti rotanti K3endo non produce trasporti del forame apicale, se non minimi ed insignificanti dal punto di vista clinico
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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