Two-year clinical performance of cast post and core self-adhesive cementation

Introduction and Objective: Endodontically treated teeth commonly present extensive tissue loss, requiring the use intraradicular posts, which provide retention for a coronal rehabilitation. Cast post and cores (CPCs) have been traditionally used in cases of marked tooth tissue loss. Case report: This case report describes two cast post and cores and subsequent rehabilitation by metal ceramic crowns. The patient was followed-up at intervals of 12 and 24 months after the rehabilitation. The posts were cemented within the root canal with self-adhesive resin cement, in a way that guarantees a perfect sealing of the root and remains stable in the oral environment. Conclusion: Self-adhesive cements are a one-step material capable of providing additional chemical adhesion to the metal, creating a monoblock, quality not found in conventional resin cements, where the adhesion occurs only in the dentin-cement interface.Introduction and Objective: Endodontically treated teeth commonly present extensive tissue loss, requiring the use intraradicular posts, which provide retention for a coronal rehabilitation. Cast post and cores (CPCs) have been traditionally used in cases of marked tooth tissue loss. Case report: This case report describes two cast post and cores and subsequent rehabilitation by metal ceramic crowns. The patient was followed-up at intervals of 12 and 24 months after the rehabilitation. The posts were cemented within the root canal with self-adhesive resin cement, in a way that guarantees a perfect sealing of the root and remains stable in the oral environment. Conclusion: Self-adhesive cements are a one-step material capable of providing additional chemical adhesion to the metal, creating a monoblock, quality not found in conventional resin cements, where the adhesion occurs only in the dentin-cement interface

Linear dimensional stability of irreversible hydrocolloids with and without disinfection at different storage times

Irreversible hydrocolloids have been used in dental practice for decades and their pouring time has been suggested to be as short as possible; however the latest generation of alginates exhibit better properties, which could influence the fidelity of the casts. Objective: To evaluate the linear dimensional stability of stone casts obtained using two irreversible hydrocolloid brands (Cavex ColorChange and Jeltrate) after disinfection. Material and methods: Samples were divided into 16 groups (n = 10) according to brand, storage time and disinfection. Impressions were taken of a metallic master model made of stainless steel with two abutments. Cast models were obtained using type IV gypsum, after disinfection with sodium hypochlorite at 1% or without any disinfection followed by storage for four different times (immediate pouring, and after 24, 72 or 120 hours storage after obtaining the impressions) and the models were measured with a digital caliper. Data were submitted to ANOVA 3-way followed by Tukey’s test (α 0.05). Conclusion: Storage longer than 24 hours affects the fidelity of casts. Disinfection does not promote significant alteration at any of the experimental times with either material.Irreversible hydrocolloids have been used in dental practice for decades and their pouring time has been suggested to be as short as possible; however the latest generation of alginates exhibit better properties, which could influence the fidelity of the casts. Objective: To evaluate the linear dimensional stability of stone casts obtained using two irreversible hydrocolloid brands (Cavex ColorChange and Jeltrate) after disinfection. Material and methods: Samples were divided into 16 groups (n = 10) according to brand, storage time and disinfection. Impressions were taken of a metallic master model made of stainless steel with two abutments. Cast models were obtained using type IV gypsum, after disinfection with sodium hypochlorite at 1% or without any disinfection followed by storage for four different times (immediate pouring, and after 24, 72 or 120 hours storage after obtaining the impressions) and the models were measured with a digital caliper. Data were submitted to ANOVA 3-way followed by Tukey’s test (α 0.05). Conclusion: Storage longer than 24 hours affects the fidelity of casts. Disinfection does not promote significant alteration at any of the experimental times with either material

Evaluation of the color stability of different temporary restorative materials

This study aimed to evaluate the color stability of different temporary restorative materials in contact with staining solutions, as well as to verify which one presents the highest resistance to staining. In this laboratory study, five types of temporary restorative materials were evaluated: self-curing acrylic resin, bis-acrylic resin, light-curing acrylic resin, CAD/CAM machinable, and 3D printed resin. Thirty samples of each material were produced in a circular mold measuring 10 mm diameter and 2 mm thickness. The materials were divided into subgroups (n=10) and immersed in solutions: Coffee, Coca-cola®, and distilled water (control). Color measurements were carried out at baseline, 1, 7, and 14 days using a digital spectrophotometer and the color parameters were calculated according to the CIEDE00 system. The color change data were subjected to two-way ANOVA (temporary material vs time) and post-hoc Tukey test (α = 0.05). The materials showed a color change only comparing baseline vs. one day, according to acceptability standard ΔE00 > 1.8. Thus, we concluded that there was a difference in color stability already on the first day of immersion. In addition, the coffee solution showed the highest color variation when compared to the other solutions. Clinical applicability: Temporary restorations are widely used in prosthetic treatments and can remain in the mouth for a considerable period. They are responsible for aesthetic and function maintenance along the rehabilitation process. In addition, they provide data for the definitive prosthesis and should assure comfort and confidence to the patient.  Thus, it is necessary that these materials are resistant and present such color stability that does not compromise the aesthetics during the treatment phase

Sperimentare la gravità con il telo elastico: linee guida e trucchi-Experience gravity with the rubber sheet: guidelines and tricks

Questo libro raccoglie schede operative, frutto di un lungo confronto con docenti, che guidano, attraverso consigli pratici, immagini, video e approfondimenti, il professore di scuola secondaria superiore nella realizzazione di attività sulla gravità utilizzando un telo elastico. Sono descritti i materiali e il procedimento necessari a costruire la struttura economica da usare in classe e il docente è accompagnato nella trattazione dei temi, dalle leggi di Keplero ai buchi neri.This book collects a series of educational cards, coming from a long discussion with teachers, that guide, through practical advice, images, videos and insights, the high school professor in the realization of different activities concerning gravity using a rubber sheet. The materials and the procedure necessary to build the economic structure to be used in the classroom are described; the teacher is then accompanied in the discussion of the topics: from Kepler's laws to black holes

L’astrofisica per insegnare la fisica di base e la fisica moderna: l’esperienza dell’Università Roma Tre

A partire dal 2010 le Indicazioni Nazionali hanno introdotto l’insegnamento della fisica moderna nelle Scuole Secondarie Superiori. Le Università e gli enti di ricerca devono quindi supportare i docenti nel loro sforzo di trattare questi argomenti avanzati in classe, proponendo il più possibile attività interattive e approcci originali. In questo documento è presentato un esempio di trattazione della fisica moderna attraverso l’astrofisica e la cosmologia. Le attività sono state proposte e testate durante il Corso di Aggiornamento in presenza dell’Università Roma Tre, con l’idea che esse possano poi essere applicate anche ad un Corso di Formazione iniziale

Introducing General Relativity in High School: A Guide for Teachers

Introducing Modern Physics represents an increasingly urgent need, towards which physics education concentrates many efforts. In order to contribute to this attempt, at the Department of Mathematics and Physics of Roma Tre University in Rome we focused on the possibility of treating General Relativity (GR) at high school level. We started with an interactive activity addressed to students that exploits the rubber sheet analogy (RSA) to show various phenomena related to gravity using the concept of space-time. Then, having verified its effectiveness, we began to include it among the initiatives the Department carry for high school teacher professional development, with the explicit aim of making them capable of carrying on the activity autonomously in the classrooms. In this paper, we analyse the teacher training approach we realized, and all the materials developed

La Fisica Moderna nella formazione degli insegnanti: l’esperienza dell’Università Roma Tre con i docenti in servizio

L’insegnamento della fisica nelle scuole superiori deve oggi includere anche argomenti di Fisica Moderna, in modo da rendere gli studenti più consapevoli della materia e delle ultime scoperte scientifiche. I docenti, però, spesso si dichiarano non in grado di affrontare questi argomenti in classe con sicurezza. E’ importante allora progettare e realizzare dei Corsi di Formazione che rispondano alle loro esigenze. In questo documento vengono descritti due esempi di attività svolte dall’Università Roma Tre e rivolte ai docenti attualmente in servizio che possono essere usati come modello per costruire la formazione iniziale degli insegnanti

Il corso online LS-EDU in Fisica Moderna

Il corso online in Fisica Moderna LS-EDU `e nato per rafforzare e aggiornare le conoscenze dei docenti su argomenti che vanno dalla Fisica Quantistica alla Relativit`a Ristretta, dalla Fisica delle Particelle Elementari alla Fisica della Materia Condensata, dall’Astrofisica e Cosmologia all’Ottica Quantistica. L’obiettivo del corso `e fornire ai docenti una conoscenza ed una padronanza degli argomenti di Fisica avanzata pi`u ampia di quella strettamente prevista nelle Indicazioni Nazionali, in modo che essi acquisiscano la confidenza necessaria per organizzare la loro didattica della Fisica Moderna. Il corso `e stato erogato per la prima volta a maggio 2016, ed `e arrivato oggi alla sua ventesima edizione, coinvolgendo oltre 1500 docenti in servizio di tutta Italia. Esso, quindi, fornisce un importante esempio di corso di aggiornamento improntato sul rafforzamento delle conoscenze e delle competenze dei docenti in servizio.The online course on Modern Physics LS-EDU was created to reinforce and update teachers’ knowledge on topics ranging from Quantum Mechanics to Special Relativity, from Particle Physics to Condensed Matter Physics, from Astrophysics and Cosmology to Quantum Optics. The aim of the course is to provide teachers with a much broader knowledge than is specified by the Indicazioni Nazionali, so that they can have sufficient confidence to autonomously organize their Modern Physics teaching. The course was held for the first time in May 2016 and has now reached its 20th edition, involving more than 1500 teachers from all over Italy. It therefore represents an important example of a refresher course based on strengthening the knowledge and skills of teachers in servic