1,721,001 research outputs found
The use of hydrogen peroxide in the experimental therapy of cysts. An in vitro analysis.
No full textAIM: Aim of the authors is to evaluate in vitro the histological alteration caused by hydrogen peroxide on a sample of radicular cysts. METHODS: Twelve radicular cysts were divided into 2 portions. The control group was histologically evaluated whereas the other portion, test, was treated with 3% hydrogen peroxide before histological analysis. Test and control portions were compared for integrity of the epithelium, inflammatory state of the cystic walls, presence of necrosis, stromal vacuolization and microvessel density (MVD). MVD was evaluated by immunohistochemistry using anti-CD34 monoclonal antibodies. RESULTS: Significantly lower epithelium integrity has been detected in the test group (p= or <0.007), (Wilcoxon test). Moreover, the test group presented a higher number of stromal vacuolization areas (p= or <0.004). However, necrosis and inflammation reported no significative differences. No significative differences were noticed for the MVD. CONCLUSION: Hydrogen peroxide showed a cytopathic and cytolytic activity in vitro. Those effects have been shown on both cysts tissues: epithelium and connective tissue. The present study did not reveal any statistically significant difference between the number of vessels in the control and in the test group. However, further in vitro and human studies are needed to validate this substance in the treatment of cysts
Minimally invasive prosthetic procedures in the rehabilitation of a bulimic patient affected by dental erosion
No full textThe population affected by dental erosion due to bulimia is generally very young. This population group has a high aesthetic requirement; the dentition in these patients is severely damaged, especially in the anterior maxillary quadrant. In terms of treatment, it is still controversial whether an adhesive rehabilitation is preferable to a longer-lasting but more aggressive conventional treatment, such as full-crown coverage of the majority of teeth. This case report describes the prosthetic rehabilitation of a young female patient previously affected by bulimia nervosa and presenting erosion of the maxillary teeth. The prosthetic rehabilitation was performed through indirect adhesive restorations of the anterior teeth and direct restorations of the posterior teeth. A clinical follow-up after 4 years showed that the occlusion remained satisfactorily restored. Posterior direct composite resin restorations and anterior indirect adhesive composite restorations proved to be an effective time and money-saving procedure to rehabilitate patients affected by dental erosion. Adhesive rehabilitation provides a functional and good aesthetic result while preserving tooth structure
The effect of different storage conditions and duration on the fracture strength of three types of translucent fiber posts
No full textOBJECTIVES:
(a) To evaluate the effects of storage duration, storage condition and type of fiber post on post fracture strength. (b) To morphologically evaluate the post structure before and after storage.
METHODS:
Three types of fiber posts were divided in different groups (n=14) according to the storage duration (1, 6, 12 months), and storage condition (dry at 37 degrees C; saline water at 37 degrees C; mineral oil at 37 degrees C and storage inside the roots of extracted human teeth immersed in saline water at 37 degrees C). Specimens were loaded in a universal testing machine with a compressive load until fracture. A 3-way ANOVA and Tukey's test (alpha=.05) were used to compare the effect of the experimental factors on the fracture strength. Two posts of each group were observed before and after the storage using a scanning electron microscope.
RESULTS:
Storage conditions and post type, had a significant effect on post fracture strength (p<0.05). The interaction between these factors was significant (p<0.05). Water storage significantly decreased the fracture strength, regardless of the post type and the storage duration. Storage inside roots, in oil, and at dry conditions did not significantly affect post fracture strength. SEM micrographs revealed voids between fibers and resin matrix for posts stored in water. Posts stored under the other conditions showed a compact matrix without porosities.
SIGNIFICANCE:
Fiber posts placed inside human root canals immersed in water are not affected by the detrimental effect of water
Jaw clenching effects in relation to two extreme occlusal features: patterns of diagnoses in a TMD patient population
No full text
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
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