Search results for " cement"
showing 10 items of 245 documents
Cariostatic effect of a light-cured, resin-reinforced glass-ionomer for bonding orthodontic brackets in vivo
1998
The aim of this study was to evaluate in vivo the cariostatic potential of the resin-reinforced glass-ionomer (Vitremer core build-up restorative; 3M Dental Product Division) when used as a bonding agent for orthodontic brackets. The mineral distribution and topography of the enamel surface adjacent to the bracket base was determined by quantitative microradiography (TMR) and confocal laser scanning microscopy (CLSM). The study was designed in split-mouth technique using 9 pairs of premolars to be extracted for orthodontic reasons. One tooth of each pair was bonded with the resin-reinforced glass-ionomer, and the control contralateral premolar with the non-fluoridated composite (Concise, 3M…
Effect of environmental conditions on the durability of polycarbonate for the protection of cultural heritage sites.
2019
Polycarbonate is a good material for covering and protecting cultural heritage sites because of its durability, mechanical properties, and transparency. However, polycarbonate degrades under environmental weathering with a significant decrease of physical and mechanical properties and loss of transparency. In this work, the contemporary presence of ultraviolet irradiation and different temperature and moisture conditions have been taken into account to study the environmental degradation of this polymer with regard to its mechanical and optical properties. The photo-oxidation reactions cause a decrease in the molecular weight and the formation of many oxygenated species. The hydrolytic sci…
Effect of addition of Nano hydroxyapatite particles on wear of resin modified glass ionomer by tooth brushing simulation
2016
Background Recently, incorporation of nanohydroxyapatite (NHA) has been suggested to improve the mechanical properties of glass ionomers (GIs). This study aimed to assess the effect of addition of NHA on wear of resin modified glass ionomer (RMGI) by tooth brushing simulation. Material and Methods In this in vitro, experimental study, NHA in 1, 2, 5, 7 and 10wt% concentrations was added to Fuji II LC RMGI powder, and 48 samples (5×5mm) in five experimental and one control group (n=8) were fabricated. After polishing, cleaning and incubation at 37°C for three weeks, the samples were weighed and subjected to tooth brushing simulation in a toothpaste slurry according to ISO14569-1. Then, they …
Las pinturas murales de los arcosolios del Cementerio del Conjunto Histórico de San Juan del Hospital de Valencia
2020
Los últimos trabajos de restauración llevados a cabo en los arcosolios del cementerio del Conjunto Histórico de San Juan del Hospital de Valencia han sacado a la luz parte de las pinturas murales que sirvieron como decoración al intradós de estas pequeñas arquitecturas funerarias. Dichas pinturas, ocultas bajo diferentes capas de cal desde mediados del siglo XIV, se suman a las descubiertas en las anteriores etapas de rehabilitación y restauración en la capilla de San Miguel y en el arcosolio llamado de Fernández Heredia. De este modo el conjunto hospitalario se sitúa entre los monumentos con más numerosos e interesantes restos pictóricos murales de época medieval de la ciudad de Valencia. …
Los canecillos de la Capilla del Cementerio de San Juan del Hospital de Valencia
2020
In the medieval cemetery of the Historic Site of San Juan del Hospital of Valencia is housed a small funeral chapel founded in the late thirteenth century by the knight Arnau de Romaní. Along its cornice there are a series of heads of animals and humans that are one of the few sculptural vestiges inserted into the Romanesque iconographic tradition that are preserved in the city. So far they have not aroused the interest of specialists and no one has dedicated a detailed study to these curious and interesting images located in the marginal spaces of such a beautiful building. This article aims to complete this gap addressing the study of the corbels of the small temple, projecting a thematic…
Shear force comparative evaluation for surface treated and non- treated 3D interim printed materials with different types of glass-ionomer cements
2020
Background The purpose of this investigation was to compare shear force of different glass-ionomer cements on 3D printed interim material in combination with and without surface pretreatment. Material and Methods 120 rectangular specimens made of printable provisional material (Bego, Bremen, Germany) were used. After post-processing the specimens were blasted with aluminum oxide 110µm (Bego, Bremen, Germany). Extra 120 non-surface treated specimens were used as an experimental negative test group. All 240 specimens were divided randomly into 6 groups. All were cemented with a compressive load of 20 N using universal testing machine Z010 (Zwick/Roell, Ulm, Germany) to ensure a comparable cem…
Mechanical and dentin bond strength properties of the nanosilver enriched glass ionomer cement
2019
Background The aim of this study was to investigate the mechanical properties and dentin microshear bond strength of a conventional glass ionomer cement (GIC) compared to GIC supplemented with silver nanoparticles (SNPs) at 0.1% and 0.2% (w/w). Material and Methods SNPs were incorporated into a conventional GIC at 0.1% and 0.2% (w/w). The unmodified GIC was used as the control group. Compressive strength, flexural strength, and micro-shear bond strength (µSBS) to dentin were evaluated using a universal testing machine. Surface microhardness was determined using a Vickers microhardness tester. The data were analyzed using one-way analysis of variance (ANOVA) and Tukey’s test. Results GICs co…
Ex vivo study of bacterial coronal leakage in indirect pulp treatment
2012
Objective: The aim of this study was to evaluate, ex vivo, bacterial coronal leakage with different antimicrobial agents applied to the dentine for indirect pulp treatment (IPT). Study Design: Sixty extracted teeth were prepared and randomly distributed into 5 groups (n=10): Group 1: no antimicrobial dentine treatment; group 2: 1% chlorhexidine (CHX)+1% thymol varnish (Cervitec®); group 3: 2 % CHX solution; group 4: 40% CHX varnish (EC40™) and group 5: Clearfil™ Protect Bond (CPB). Ten teeth served as controls. The teeth were restored using a resin-modified glass ionomer cement (GIC) and then mounted in a two-chamber device. The coronal access was exposed to Streptococcus mutans for 45 days…
Entre moneo e memini. Arquitectura funeraria militar en el sureste de Sicilia.
2023
Nel luglio del 1943 la costa sud-orientale della Sicilia fu teatro dello sbarco attuato dalle forze militari Alleate da cui prende avvio la liberazione dal nazi-fascismo dell’Italia e dell’Europa. Gli eventi bellici siciliani furono inevitabilmente piuttosto cruenti e videro un numero elevato di morti di soldati italiani, tedeschi e dei militari delle forze anglo-americane. Sin dagli anni Cinquanta del ’900, la Commonwealth War Grave Commission e la Volksbund, al fine di onorare i militari Alleati e tedeschi caduti in battaglia, avviarono la realizzazione di diversi cimiteri di guerra tra Agira, Catania, Siracusa e Motta Sant’Anastasia. I primi tre, progettati da Louis de Soissons, destinat…
Effect of thermocycling with or without 1 year of water storage on retentive strengths of luting cements for zirconia crowns
2015
Abstract Statement of problem Bond stability between zirconia crowns and luting cement and between cement and dentin is a main concern; however, only limited evidence is available as to its longevity. Purpose The purpose of this in vitro study was to measure the retentive strengths of 7 self-adhesive cements (RelyX Unicem Aplicap, RelyX Unicem Clicker, RelyX Unicem 2 Automix, iCEM, Maxcem Elite, Bifix SE, SpeedCem), 2 adhesive cements with self-etch primers (Panavia 21, SEcure), 1 glass ionomer cement (Ketac Cem), 1 resin-modified glass ionomer cement (Meron Plus), and 1 zinc phosphate cement for luting zirconia crowns (LAVA) to extracted teeth after thermocycling with or without 1 year of …