Search results for "visual"
showing 10 items of 7386 documents
Discrimination and provenances of Phoenician red slip ware using both the solid state electrochemistry and petrographic analyses
2020
[EN] Solid state electrochemistry based on the voltammetry of immobilized microparticles (VIMP) methodology is applied to a series of 80 Phoenician Red Slip samples from the archaeological sites of Motya (Sicily, Italy), Mogador (Morocco), Ramat-Rahel (Israel), Sulky (Sardinia, Italy), Tas Silg (Malta), Pantelleria (Italy), and Cadiz (Spain), dated from the 8(th) to the 6(th) century BC. Upon attachment of sub-microsamples to graphite electrodes in contact with aqueous H2SO4 electrolyte, voltammetric features due to the reduction of Fe(III) minerals and the oxidation of Fe(II) ones, complemented with electrocatalytic effects on oxygen reduction and oxygen evolution reactions, provide charac…
Resistance to bond degradation between dual-cure resin cements and pre-treated sintered CAD-CAM dental ceramics
2012
Objective: To evaluate the bond stability of resin cements when luted to glass-reinforced alumina and zirconia CAD/CAM dental ceramics. Study design: Eighteen glass-infiltrated alumina and eighteen densely sintered zirconia blocks were randomly conditioned as follows: Group 1: No treatment; Group 2: Sandblasting (125 µm Al2O3-particles); and Group 3: Silica-coating (50 µm silica-modified Al2O3-particles). Composite samples were randomly bonded to the pre-treated ceramic surfaces using different resin cements: Subgroup 1: Clearfil Esthetic Cement (CEC); Subgroup 2: RelyX Unicem (RXU); and Subgroup 3: Calibra (CAL). After 24 h, bonded specimens were cut into 1 ± 0.1 mm2 sticks. One-half of th…
Bond strength evaluation of the veneering-core ceramics bonds.
2009
The purpose of this study was to determine whether the bond of veneering porcelain to a ceramic core in bilayered ceramics was similar to that of the metal ceramic control of well known behaviour. Six groups of nine specimens each were fabricated, whose dimensions were 15 mm long and 8 mm in diameter at the core, and 2 mm long and 8 mm in diameter for the veneer. The groups were GR. 1 (control group): CrNi alloy/d.SIGN (Ivoclar), GR. 2: IPS e.maxPress/IPS e.maxCeram (Ivoclar), GR. 3: IPS e.maxZirCad/ IPS e.maxZirPress (Ivoclar), GR. 4: IPS e.maxZirCad/IPS e.maxCeram (Ivoclar), GR. 5: Lava Frame (3M ESPE)/ Lava Ceram (3M ESPE) and GR. 6: Lava Frame (3M ESPE)/IPS e.maxCeram (Ivoclar). A shear…
Microstructure and mechanical effects of spark plasma sintering in alumina monolithic ceramics
2013
The specific effects of spark plasma sintering (SPS) on the creep behavior, microstructure and mechanical properties of alumina monolithic ceramic were investigated. SPS introduces strains that concentrate at grain boundaries and inhibit crack growth, resulting in an improvement in the flexural strength and fracture toughness. However, creep blocks grain boundary movements and decreases the reliability of the material. These strains can be removed by a post-sintering thermal treatment, which plays an important role in the distribution of dislocations.
Full maxillary rehabilitation with an all-ceramic system
2009
With the appearance of all-ceramic systems, providing a choice of framework porcelains and allowing the same material to be used for the veneer, it is now possible to select the ideal structure in terms of both function and esthetics. Silicate ceramics allow porcelain laminate veneers and crowns to be used in the anterior region, providing excellent esthetics; while for the posterior area, where function takes precedence, oxide ceramics, specifically zirconium oxide, are preferred. The IPS e.max ceramic system, heir apparent to the IPS Empress 2 system, combines the advantages of zirconium oxide ceramics (IPS e.max Zircad) with the excellent esthetic qualities of silicate ceramics (IPS e.ma…
Effects of femtosecond laser and other surface treatments on the bond strength of metallic and ceramic orthodontic brackets to zirconia.
2017
Femtosecond laser has been proposed as a method for conditioning zirconia surfaces to boost bond strength. However, metallic or ceramic bracket bonding to femtosecond lasertreated zirconia surfaces has not been tested. This study compared the effects of four conditioning techniques, including femtosecond laser irradiation, on shear bond strength (SBS) of metallic and ceramic brackets to zirconia.Three hundred zirconia plates were divided into five groups: 1) control (C); 2) sandblasting (APA); 3) silica coating and silane (SC); 4) femtosecond laser (FS); 5) sandblasting followed by femtosecond laser (APA+SC). A thermal imaging camera measured temperature changes in the zirconia during irrad…
BIOACTIVE GLASS CERAMIC
1983
The practicability of the bioactive glass ceramic Cernvitnl® in ear surgery was tested in animals. The histological findings are presented. Over the last 3 years implants of bioactive glass ceramic were used in humans. Prostheses for the total or partial reconstruction of the ossicular chain and the reconstruction of the bony wall of the outer ear canal were fashioned. We have conducted about 300 tympanoplasties and 60 total or partial reconstructions of the bony wall of the outer ear canal. The otoscopic and functional results were satisfactory.
Implant-supported metal-ceramic and resin-modified ceramic crowns: A 5-year prospective clinical study.
2018
Abstract Statement of problem Because of market demand for innovation, new restoration materials have been introduced without adequate testing; clinical failure may be the consequence, and clinical studies are needed. Purpose The purpose of this clinical study was to evaluate the biological and mechanical clinical behavior of implant-supported resin-modified ceramic crowns compared with that of metal-ceramic crowns. Material and methods Forty-two participants aged between 35 and 65 years received single implants in posterior edentulous sites. After the osseointegration period, half of the implants (selected randomly) (n=25) were restored with metal-ceramic crowns (MC group) and the other ha…
Tissue reactions to glass ceramics in the middle ear
1981
The bioactive glass ceramic "Ceravital" was used to fashion prostheses for the replacement of various ossicles in the middle ear. They were tested in 70 rabbit ears, where they were accepted in osseous areas without formation of surrounding fibrous tissue. Histological examinations regularly showed an osseous bond with the surrounding bony tissue. Mucous membrane covered these ossicular chain prostheses and showed no evidence of inflammatory reactions. Glass ceramic implants were also used to reconstruct the ossicular chain and the posterior wall of the outer ear canal in 100 patients. The functional results were satisfactory in all cases.
Electrophysiological Investigations of Retinogeniculate and Corticogeniculate Synapse Function
2019
The lateral geniculate nucleus is the first relay station for the visual information. Relay neurons of this thalamic nucleus integrate input from retinal ganglion cells and project it to the visual cortex. In addition, relay neurons receive top-down excitation from the cortex. The two main excitatory inputs to the relay neurons differ in several aspects. Each relay neuron receives input from only a few retinogeniculate synapses, which are large terminals with many release sites. This is reflected by the comparably strong excitation, the relay neurons receive, from retinal ganglion cells. Corticogeniculate synapses, in contrast, are simpler with few release sites and weaker synaptic strength…