1,720,997 research outputs found

    Tooth as graft material: Histologic study.

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    BACKGROUND An effective regenerative protocol is key to reestablish and maintain the hard and soft tissue dimensions over time. The choice of the graft material and its properties also could have an impact on the results. To prevent alveolar ridge dimensional changes, since numerous graft materials have been suggested and in the past years, a growing interest in teeth material has been observed as a valuable alternative to synthetic biomaterials. AIM The aim of the study was to explore the histomorphometric outcomes of tooth derivative materials as used as bone substitute material in socket preservation procedure. METHODS After alveolar socket preservation (ASP) procedures using autologous demineralized tooth as graft material prepared by means of an innovative device, was evaluated. A total of 101 histological samples, from 96 subjects, were analyzed by evaluating the total amount of bone (BV), residual tooth material (residual graft, TT), and vital bone (VB). The section from each sample was then split in nine subsections, resulting in 909 subsections, to allow statistical comparison between the different areas. RESULTS It was not noticed a statistically significant difference between maxillary and mandibular sites, being the amount of VB in upper jaw sites 37.9 ± 21.9% and 38.0 ± 22.0% in lower jaw sites and the amount of TT was 7.7 ± 12.2% in maxilla and 7.0 ± 11.1% in mandibles. None of the other considered parameters, including defect type and section position, were statistically correlated to the results of the histomorphometric analysis. CONCLUSIONS ASP procedure using demineralized autologous tooth-derived biomaterial may be a predictable procedure to produce new vital bone potentially capable to support dental implant rehabilitation

    Medium- and Long-Term Survival Rates of Implant-Supported Single and Partial Restorations at a Maximum Follow-up of 12 Years: A Retrospective Study

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    Purpose: To present medium- and long-term biologic outcomes of implant-supported single-tooth restorations and fixed partial dentures and to analyze their correlations with prosthesis and patient characteristics. Materials and Methods: The records of patients treated with implant-supported fixed restorations between 2004 and 2019 reporting the presence or absence of peri-implantitis and/or implant failure were analyzed. The cumulative survival rate (%) over time was calculated, as well as the cumulative prevalence of units free of peri-implantitis. Results: A total of 344 implants in 112 patients were included, with a mean follow-up period of 5.3 +/- 4.0 years after loading. The cumulative survival rates for implants supporting single crowns and fixed partial dentures were 98.11% and 100% after 5 years, respectively, and 97.43% and 98.96% after 10 years, with an overall survival rate of 91.69% after 12 years. At the patient level, the implant survival rates were 95.42%, 92.73%, and 85.31% at 5, 10, and 12 years, respectively. The cumulative rate of implants free from peri-implantitis was 87.46% at the implant level and 72.39% at the patient level. Implant and prosthesis characteristics did not affect the long-term occurrence of implant failure or peri-implantitis. The development of peri- implantitis was statistically correlated with patient smoking habits, but not with history of periodontitis or with diabetes mellitus. Conclusion: Implants supporting single crowns and fixed partial dentures showed relatively high medium- and long-term survival rates that were not influenced by the implant or prosthesis characteristics, including the retention method. As for patient characteristics, only smoking was correlated with the occurrence of peri-implantitis

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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

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    We 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

    Author Index

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    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We 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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