1,720,963 research outputs found
Continuous craniofacial growth in adult patients treated with dental implants in the anterior maxilla
No full textBACKGROUND:
In the Literature, there are several studies demonstrating that infraposition happens also in adult patients.
PURPOSE:
To conduct a retrospective evaluation of infraocclusion of implant-retained crowns in the anterior maxilla of adult patients and of the patient awareness and perception of the problem.
MATERIAL AND METHODS:
From January to June 2017, all adult patients who in the last 5 to 20 years had received in the same clinic implant restorations in the upper anterior maxilla were recalled to assess the presence of crown infraocclusion. Ninety-four patients were recalled. Twenty-six males, 34 females, with 76 implants were included in the study. According to the age, patients were divided into group I (30 years: 14 males, 20 females). Digital photographs, taken at the time of final prosthesis delivery (T0) and at time of the study examination (T1) were compared by three blinded previously calibrated examiners. Cast models of the dental arches were taken at T1 and served as a reference for infraocclusion measurements. According to the Literature, cases were included in three categories: infraocclusion 1 mm. An awareness and perception score (APS) was prepared to classify patients in: "unaware patients" (0), "aware but disinterested patients" (1), "aware patients requiring explications" (2), and "aware patients requiring treatment" (3).
RESULTS:
Infraocclusion was present in 73.3% of all cases, 65.4% among males, 79.4% among females. Infraocclusion was less than 1 mm in 88.2% of males and in 85.1% of females. No significant differences were found for sex (P = .223). No significant differences were found for age: group I: 47.7%, group II: 52.2%, (P = .481). The overall APS was: "unaware patients" = 38.6%, "aware but disinterested patients" = 27.3%, "aware patients requiring explications" = 15.9%, "aware patients requiring treatment" = 18.2%
Soft and hard tissue response to an implant with a convergent collar in the esthetic area: preliminary report at 18 months
No full textAIM: The purpose of this prospective cohort study was to investigate, over an 18-month period, soft and hard tissue response to a transmucosal implant with a convergent collar inserted in the anterior maxillary esthetic area.MATERIALS AND METHODS: From June 2013 to January 2014, 14 consecutive patients were enrolled (7 men and 7 women; mean age 63.7 ± 14 years) with 20 implants, needing at least one implant-supported restoration between the canines in the maxillary anterior esthetic area. Six months after hopeless tooth extraction and an alveolar socket graft, a transmucosal-type implant with convergent collar walls was inserted in a midcrestal position with mini-flap surgery. An impression was taken 2 months later, and a definitive abutment with a provisional restoration was positioned. The final restoration was seated 2 weeks later. Clinical parameters, photographs, radiographs, and impressions were taken at this timepoint, and after 6 and 18 months. Using dedicated software, radiographic analysis (to detect marginal bone-level changes) and cast analysis (to detect soft tissue vertical and horizontal changes) were performed.RESULTS: At the 18-month follow-up, all implants were clinically osseointegrated, stable, and showed no sign of infection. At baseline, interproximal radiographs revealed no bone defect around the implant. After an initial minimal bone loss (0.09 ± 0.144 mm), radiographic analysis showed a stable condition of bone remodeling (mean value 0.09 ± 0.08; range 0.0 to 0.5 mm) at the 18-month follow-up. No statistically significant horizontal dimensional changes of the alveolar ridge were observed between each timepoint. Mean soft tissue levels significantly improved between baseline and 18 months. The mean heights of the mesial papilla (MP) and distal papilla (DP) changes were 0.38 ± 0.22 and 0.47 ± 0.31, respectively. The level of the labial gingival margin (LGM) was 1.01 ± 0.63. Periodontal parameters never exceeded the physiological levels.CONCLUSIONS: Within the limitations of this preliminary study, the analyzed implants produced positive results in these esthetically demanding cases. This outcome should encourage long-term studies in order to assess, through controlled clinical trials, whether this convergent collar design offers advantages over other designs. Furthermore, due to the peculiar crestal module, together with the use of delayed implant insertion and a postextraction ridge preservation technique with biomimetic hydroxyapatite, the analyzed implants seem to help prevent the negative bone remodeling typically associated with two-piece implant systems, but without the well-known drawbacks of traditionally designed transmucosal implants. Therefore, wherever crestal bone preservation is a critical issue for clinical success in the anterior maxillary area can be considered of particular interest
Soft and hard tissue response to an implant with a convergent collar in the esthetic area: preliminary report at 18 months
No full textAim: The purpose of this prospective cohort study was to investigate, over an 18-month period, soft and hard tissue response to a transmucosal implant with a convergent collar inserted in the anterior maxillary esthetic area.
Materials and methods: From June 2013 to January 2014, 14 consecutive patients were enrolled (7 men and 7 women; mean age 63.7 ± 14 years) with 20 implants, needing at least one implant-supported restoration between the canines in the maxillary anterior esthetic area. Six months after hopeless tooth extraction and an alveolar socket graft, a transmucosal-type implant with convergent collar walls was inserted in a midcrestal position with mini-flap surgery. An impression was taken 2 months later, and a definitive abutment with a provisional restoration was positioned. The final restoration was seated 2 weeks later. Clinical parameters, photographs, radiographs, and impressions were taken at this timepoint, and after 6 and 18 months. Using dedicated software, radiographic analysis (to detect marginal bone-level changes) and cast analysis (to detect soft tissue vertical and horizontal changes) were performed.
Results: At the 18-month follow-up, all implants were clinically osseointegrated, stable, and showed no sign of infection. At baseline, interproximal radiographs revealed no bone defect around the implant. After an initial minimal bone loss (0.09 ± 0.144 mm), radiographic analysis showed a stable condition of bone remodeling (mean value 0.09 ± 0.08; range 0.0 to 0.5 mm) at the 18-month follow-up. No statistically significant horizontal dimensional changes of the alveolar ridge were observed between each timepoint. Mean soft tissue levels significantly improved between baseline and 18 months. The mean heights of the mesial papilla (MP) and distal papilla (DP) changes were 0.38 ± 0.22 and 0.47 ± 0.31, respectively. The level of the labial gingival margin (LGM) was 1.01 ± 0.63. Periodontal parameters never exceeded the physiological levels.
Conclusions: Within the limitations of this preliminary study, the analyzed implants produced positive results in these esthetically demanding cases. This outcome should encourage long-term studies in order to assess, through controlled clinical trials, whether this convergent collar design offers advantages over other designs. Furthermore, due to the peculiar crestal module, together with the use of delayed implant insertion and a postextraction ridge preservation technique with biomimetic hydroxyapatite, the analyzed implants seem to help prevent the negative bone remodeling typically associated with two-piece implant systems, but without the well-known drawbacks of traditionally designed transmucosal implants. Therefore, wherever crestal bone preservation is a critical issue for clinical success in the anterior maxillary area can be considered of particular interest
Fibroblast Interaction with Different Abutment Surfaces: In Vitro Study
No full textBackground: Attaining an effective mucosal attachment to the transmucosal part of the
implant could protect the peri-implant bone. Aim: To evaluate if chair side surface treatments
(plasma of Argon and ultraviolet light) may affect fibroblast adhesion on different titanium surfaces
designed for soft tissue healing. Methods: Grade 5 titanium discs with four different surface
topographies were subdivided into 3 groups: argon-plasma; ultraviolet light, and no treatment.
Cell morphology and adhesion tests were performed at 20 min, 24 h, and 72 h. Results: Qualitative
observation of the surfaces performed at the SEM was in accordance with the anticipated features.
Roughness values ranged from smooth (MAC Sa = 0.2) to very rough (XA Sa = 21). At 20 min,
all the untreated surfaces presented hemispherical cells with reduced filopodia, while the cells on
treated samples were more spread with broad lamellipodia. However, these differences in spreading
behavior disappeared at 24 h and 72 h. Argon-plasma, but not UV, significantly increased the number
of fibroblasts independently of the surface type but only at 20 min. Statistically, there was no surface
in combination with a treatment that favored a greater cellular adhesion. Conclusions: Data showed
potential biological benefits of treating implant abutment surfaces with the plasma of argon in relation
to early-stage cell adhesion
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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