1,721,046 research outputs found
The Effect of Crown-to-Implant Ratio on the Clinical Performance of Extra-Short Locking-Taper Implants
The aim of the present prospective 5-year study was to evaluate the influence of crown-to-implant ratio (C/I ratio) on the survival, peri-implant marginal bone loss, and complications of extra-short (6.5 mm) locking-taper implants placed in the posterior areas of the jaw
Immediate Loading of Tapered Implants Placed in Postextraction Sockets and Healed Sites
The aim of the present study was to compare the survival, stability, and complications of immediately loaded implants placed in postextraction sockets and healed sites
Digitally-oriented materials: focus on lithium disilicate ceramics.
The present paper was aimed at reporting the state of the art about lithium disilicate ceramics. The physical, mechanical, and optical properties of this material were reviewed as well as the manufacturing processes, the results of in vitro and in vivo investigations related to survival and success rates over time, and hints for the clinical indications in the light of the latest literature data. Due to excellent optical properties, high mechanical resistance, restorative versatility, and different manufacturing techniques, lithium disilicate can be considered to date one of the most promising dental materials in Digital Dentistry
Predictive variables derived from panoramic radiographs for impacted maxillary cuspids treated with easy cuspid system
The aim of the current study was to find, by means of panoramic radiographs, a viable statistical method to forecast the duration of orthodontic traction of impacted maxillary cuspids. The treatment sample consisted of 51 palatal impacted cuspids (19 unilateral and 32 bilateral) in 35 patients (aged between 10.5 and 17.5 y) with a cervical vertebral maturation between cervical stage 1 and 4. Each patient underwent the same combined surgical-orthodontic technique. Anamnestic data as well as pretreatment panoramic radiograph and cephalogram with European Board of Orthodontics analysis were recorded for each case. Eight radiographic indicators were derived from panoramic films to define the reliable position of the impacted cuspid. Multiple regression analysis was used. All cuspids were successfully treated with an average traction time of 99 days (range, 33-188 d). The pretreatment radiographic features assessed on the panoramic radiographs did not significantly affect the duration of traction. The formula based on α angle, d1 distance, and S sector forecasted an average traction time of 123 days (range, 63-210 d), which is longer than the real time. No relevant correlations were found between orthodontic traction time and pretreatment radiograph parameters derived from panoramic film at the beginning of the treatment. The classic formula elaborated by Crescini could not be applied to the patients of this study, who were treated with the Easy Cuspid method
Going Beyond Counting First Authors in Author Co-citation Analysis
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
“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
Scanning Electron Microscope (SEM) evaluation of the interface between a nanostructured calcium-incorporated dental implant surface and the human bone
Purpose. The aim of this scanning electron microscope (SEM) study was to investigate the interface between the bone and a novel nanostructured calcium-incorporated dental implant surface in humans. Methods. A dental implant (Anyridge®, Megagen Implant Co., Gyeongbuk, South Korea) with a nanostructured calcium-incorporated surface (Xpeed®, Megagen Implant Co., Gyeongbuk, South Korea), which had been placed a month earlier in a fully healed site of the posterior maxilla (#14) of a 48-year-old female patient, and which had been subjected to immediate functional loading, was removed after a traumatic injury. Despite the violent trauma that caused mobilization of the fixture, its surface appeared to be covered by a firmly attached, intact tissue; therefore, it was subjected to SEM examination. The implant surface of an unused nanostructured calcium-incorporated implant was also observed under SEM, as control. Results. The surface of the unused implant showed a highly-structured texture, carved by irregular, multi-scale hollows reminiscent of a fractal structure. It appeared perfectly clean and devoid of any contamination. The human specimen showed trabecular bone firmly anchored to the implant surface, bridging the screw threads and filling the spaces among them. Conclusions. Within the limits of this human histological report, the sample analyzed showed that the nanostructured calcium-incorporated surface was covered by new bone, one month after placement in the posterior maxilla, under an immediate functional loading protocol.</p
Appropriate Similarity Measures for Author Cocitation Analysis
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
Is Low Serum Vitamin D Associated with Early Dental Implant Failure? A Retrospective Evaluation on 1625 Implants Placed in 822 Patients
Aim. To investigate whether there is a correlation between early dental implant failure and low serum levels of vitamin D. Methods. All patients treated with dental implants in a single centre, in the period 2003–2015, were considered for enrollment in this study. The main outcome was early implant failure. The influence of patient-related variables on implant survival was calculated using the Chi-square test. Results. 822 patients treated with 1625 implants were selected for this study; 27 early failures (3.2%) were recorded. There was no link between gender, age, smoking, history of periodontitis, and an increased incidence of early failures. Statistical analysis reported 9 early failures (2.2%) in patients with serum levels of vitamin D > 30 ng/mL, 16 early failures (3.9%) in patients with levels between 10 and 30 ng/mL, and 2 early failures (9.0%) in patients with levels <10 ng/mL. Although there was an increasing trend in the incidence of early implant failures with the worsening of vitamin D deficiency, the difference between these 3 groups was not statistically significant (P=0.15). Conclusions. This study failed in proving an effective link between low serum levels of vitamin D and an increased risk of early implant failure. Further studies are needed to investigate this topic
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