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LA CEMENTAZIONE IN COMPOSITO DELLE FACCETTE IN CERAMICA: CONFRONTO FRA DUE METODICHE
No full textLA CEMENTAZIONE IN COMPOSITO DELLE FACCETTE IN CERAMICA: CONFRONTO FRA DUE
METODICHE
Feletto L.*, Donà M., Zambon V., Favero G., Stellini E.
Università degli Studi di Padova – Corso di Laurea in Odontoiatria e Protesi Dentatria - Cattedra di Parodontologia
Clinica – Direttore: Prof. Edoardo Stellini
Scopo del lavoro: Le faccette in ceramica rappresentano una delle ultime frontiere dell’odontoiatria estetica e
cosmetica. L’obiettivo di questo lavoro è stato quello di confrontare sperimentalmente due metodiche di cementazione
adesiva dei manufatti: la tecnica con composito riscaldato e la tecnica con composito a freddo.
Materiali e metodi: Sono stati selezionati 20 incisivi centrali, divisi random in due gruppi di 10 elementi ciascuno.
I denti sono stati preparati con tecnica butt-joint in sola superficie smaltea per uno spessore massimo di 0,7 mm.
Mordenzati con acido orto fosforico al 37% per 30 secondi, ibridizzati con adesivo e polimerizzati. Le faccette sono
state mordenzate con acido idrofluoridrico per 30 secondi, trattate con silano caldo, spalmate di adesivo, non
polimerizzate, e caricate di composito. Il composito del gruppo A era a temperatura ambiente, quello del gruppo B
riscaldato a 45°C. I manufatti sono stati posizionati sui denti; sono stati rimossi i debordi di composito ed isolati i bordi
con glicerolo liquido. Il campione è stato polimerizzato per 120 secondi.
In laboratorio sono state eseguite per ogni dente due sezioni al microtomo, una mediana e una marginale. Di ciascuna
sezione sono state ingrandite 3 parti: margine cervicale, porzione centrale, margine incisale. Le sezioni così ottenute
sono state sottoposte a doratura per SEM. Gli ingrandimenti al SEM sono stati ripetuti, costanti per tutti i campioni a
35, 200 e 350 volte. Sono state misurate le distanze tra unità dente – composito e faccetta nelle 3 posizioni e costruite
delle tabelle. Valutata visivamente la distribuzione dei riempitivi nei due gruppi alla ricerca di eterogeneità.
Risultati: In fase di cementazione si è trovata una maggiore maneggevolezza nel gruppo B. In fase di preparazione 2
faccette del gruppo A e 4 del gruppo B si sono separati nettamente dall’unità dente – composito. Le distanze misurate
nelle diverse posizioni hanno rivelato un minor spessore di composito tra dente e faccetta nel gruppo B (circa 4,5%).
Dato rilevante statisticamente. All’esame visivo non si sono rilevati cambiamenti nella distribuzione del riempitivo, non
si sono viste inclusioni di bolle d’aria in fase di cementazione tra gruppo A e B. tuttavia il gap tra composito e ceramica
è visibile in tutte le fotografie.
Conclusioni: Il riscaldamento del composito agevola la cementazione della faccetta: riduce lo spessore di cementazione
e ne aumenta la maneggevolezza, riducendo il rischio di frattura durante il lavoro. Il riscaldamento delle masse sembra
non modificare sostanzialmente il composito, tuttavia il fatto che le faccette cementate a caldo si siano staccate con
maggior facilità ci ha spinto ad avviare nuovi studi. A breve saranno pubblicati i risultati ottenuti
L'incidenza delle agenesie in pazienti pediatrici sottoposti a trattamento ortodontico: confronto tra la popolazione di Maribor (Slovenia) e Treviso.
No full textMISURAZIONE ELETTRONICA DELLE TASCHE PARODONTALI: METODOLOGIA D’USO E ATTENDIBILITA’ DELLA METODICA
No full textIntegrated seismic and energy retrofit interventions on a urm masonry building: The case study of the former courthouse in fabriano
No full textFollowing the 2016 central Italy earthquakes, the high seismic vulnerability of existing buildings is once again at the center of the debate. Indeed, the majority of the Italian building stock (around 60%) was built before adopting the first seismic provisions (1974) and in a territory entirely characterized by medium to high levels of seismic hazard. On the other hand, the first provisions addressing thermal performance criteria were introduced in 1976 but with limited impact. A consistent reduction in energy consumption was further achieved in 1991, when even more buildings were erected. As a consequence, the Italian building stock is characterized by reduced seismic capacity and poor energy efficiency and, to optimize the available resources, combined retrofit interventions approaches are required. In this context, a synergic strategy for the seismic and energy retrofit of a unreinforced masonry (URM) building was proposed. The former Courthouse in Fabriano (Ancona, Marche), a strategic, three-story, unreinforced masonry building in the network of permanent monitoring systems of the Italian Department of Civil Protection, was selected as a case study. The overall effectiveness of various solutions of combined structural refurbishment and energy retrofit interventions, having different levels of invasiveness on the building, was assessed. In addition, a common methodology based on the expected annual losses allowed evaluating the financial feasibility of the proposed integrated interventions and estimating the changes in the return of the retrofitting investment in various seismic and climate zones. The results also show how the payback period could be significantly reduced by incentives and regulatory frameworks that currently favour the execution of integrated interventions
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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