1,721,003 research outputs found
Propagation of maxima and strong maximum principle for fully nonlinear degenerate elliptic equations. Part II: concave operators
No full textComparison and existence results for evolutive non-coercive first-order Hamilton-Jacobi equations
No full textIn this paper we prove a comparison result between viscosity subsolutions and supersolutions to Hamilton-Jacobi equations of the form u_t+H(x,Du)=0 in R^Nx(0,T) where the Hamiltonian H may be noncoercive in the gradient Du. As a consequence of the comparison result and the Perron's method we get the existence of a continuous solution of this equation
Radiosurgery in dentistry: a review
No full textThe aim of the present study was to analyse the clinical potential of radiosurgery applied to modern dentistry through a revision of the indexed literature. Radiosurgery represents a recent form of electrosurgery working at a frequency of 3.0-4.0 MHz. The depth of penetration of the waves is inversely proportional to the frequency. Radiowaves working at high frequency express a lower penetration with a consequent lower tissue alteration. The authors analyzed the literature in order to give to the scientific community an overview of the possible applications of radiosurgery in the clinical dental practice and their effectiveness. Radiosurgery can be used in prosthodontics, in periodontal and implant surgery, in the treatment of trigeminal neuralgia, in the treatment of obstructive sleep apnea syndromes (OSAS) and in endodontics. Our analysis shows that although there are few articles in indixed literature on the applications of radiosurgery in dentistry, thanks to the benefits that derive from it, radiosurgery will spread more in the daily clinical practice of the dentists
Influence of implant scanbody material and operator on scanning fluency and polygonal mesh numbers of digital impression: an in vitro study
No full textThe purpose of this study is to evaluate the influence of implant scanbody (ISB) material and operator on scanning fluency and polygonal mesh numbers of a confocal microscopy intraoral scanning (IOS). An edentulous maxillary master model with 6 implant analogues was assembled. Thereafter 3 ISBs featured with same geometry but different materials (polyetheretherketone (PK), titanium (T) and PK with a titanium base (PKT)) were produce and scanned according to a randomized sequence by three different operators. The confocal microscopy IOS resulted in 45 STL test files that were processed to a dedicate software to obtain the request data. The overall analysis of fluency (imm/sec) showed the following results: mean 11.997 imm/sec, SD 2.355. The multivariate analysis showed statistical significance of material (p<.0001) and operator (p<.0001) influence. The univariate analysis referred to polygonal mesh numbers expressed the following results: mean 30327.8, SD 2432.5. The multivariate analysis stressed how there is a related effect to materials (p<.0001) and operator (p=0.0205). PKT represented the material with the best results for both. Analyzing the overall distribution histogram for scanning fluency, the IOS device seems to work with higher frequency at level of 13 imm/sec. The distribution of the measurements in the reference histograms showed an effect related to both variables referring to scanning fluency as well as to polygonal mesh numbers. Operator can be considered as a random effect; regarding the materials, the difference between PKT and PK can be related to the different base material. The dissimilar optical properties of T justify the different behavior
The health of soft tissues around four dental implants loaded immediately supporting a 4-year-old fixed screw-retained prosthesis
Full text linkThe aim of this study was to assess the soft tissues health around the implant/abutment interfaces of
fixed screw-retained prosthesis supported by four dental implants after at least 1-year in function. All the
implants were placed between December 1, 2015 and April 30, 2019. Digital implant surgical planning
was performed for all the complete-arch rehabilitations and then full-guided surgery was performed.
The fixed-interim prostheses were delivered the day of the surgery and replaced by definitive prostheses
after the healing period. Patients were followed-up to determinate peri-implant scores, such as Plaque
Score (PS) and Bleeding on Probing (BoP). A total of 160 implants were placed in 37 patients, whereas 3
patients received both arches rehabilitated. A total of 40 complete-arch rehabilitations were performed,
26 in the maxilla and 14 in the mandible. Only 5 implants failed resulting in an overall implant survival
rate of 96.9%. BoP was detected around 6 implants (3.7%) and 16 implants showed a superficial amount
of plaque resulting a Plaque Score of 10%. Within the limitation of this study, it seems that the use of a
fixed screw-retained prostheses supported by four dental implants to rehabilitate edentulous jaws could
be a valid treatment option in the short and medium term without critical peri-implant issues. However,
several perspective studies with longer follow-up are needed to achieve more predictable results
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
Guided endodontic microsurgery in apicoectomy: a review
No full text: The purpose of this review was twofold. The first aim was to show predictable protocols of guided endodontic microsurgery (EMS) and to describe its clinical outcomes. The second aim was to verify the accuracy of this technique compared to the traditional pathway. An electronic search of publications was established from two electronic databases, Cochrane and PubMed, by two independent researchers. The search strategy used a combination of controlled vocabulary and free-text words. Inclusion and exclusion criteria were defined by the authors before the start of the study. Inclusion criteria were: all studies published in English language; studies in vivo on humans; human cadaver studies; studies analyzing guided surgery in apicoectomy. The initial search yielded 67 citations, of which 10 were included. The studies included in this review analysis have shown two different technique both for digitization of dental arch and for surgical procedures too. Guided endodontic micro-surgery is a more predictable technique with less intra-operative and post-operative complications compared to the "freehand" technique and this procedure has shown a greater accuracy
Application of the radiosurgery assisted gingival displacement technique in the aesthetic area: A case report
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