Search results for "Titanium"
showing 10 items of 878 documents
Candida albicans biofilms on different materials for manufacturing implant abutments and prostheses
2019
[EN] Background: Morphological, physical and chemical properties of both implants and prostheses can determine the biofilm formation on their surface and increase the risk of biological complications. The aim of this study was to evaluate the capacity of biofilm formation of Candida albicans on different materials used to manufacture abutments and prostheses. Material and Methods: Biofilm formation was analyzed on cp grade II titanium, cobalt-chromium alloy and zirconia, silicone, acrylic resin (polymethylmethacrylate) and nano-hybrid composite. Some samples were partially covered with lithium disilicate glass ceramic to study specifically the junction areas. C. albicans was incubated in a …
Development and viability of biofilms grown on experimental abutments mimicking dental implants: an in vivo model
2019
Background To determine whether an experimental abutment mimicking the macro- and microstructure of a dental implant is a suitable method for recovering biofilm, and to describe the features of biofilms formed around such abutments on healthy implants. Material and Methods Experimental abutments were used in 15 patients without peri-implant diseases. After 14 days’ absence of dental hygiene in this area, the abutments were retrieved and analyzed through confocal laser scanning microscopy and scanning electron microscopy. The biofilm formation on the surface of the first 5 abutments was determined by a fluorescence-staining method using SYTO9 nucleic acid stain. In order to study the biofilm…
On the possibility of synthesizing multilayered coatings in the (Ti,Al)N system by RGPP: A microstructural study
2019
International audience; Radiofrequency magnetron sputtering combined with reactive gas pulsing process was used to synthesize two titanium aluminum nitride multilayer films using a periodically controlled nitrogen flow rate changing from 0.4 to 1 sccm (sample S04-1) and from 0 to 1 sccm (sample S0-1). A metallic TiAl buffer layer was deposited on the etched substrates before the deposition to enhance their adhesion. The films were characterized using mainly transmission electron microscopy and electron diffraction. The role of the crystallinity of the buffer TiAl metallic layer deposited before gas introduction on the growth orientations is emphasized. It is shown that the formation of a mu…
Structural and electrical properties of magnetron sputtered Ti(ON) thin films:The case of TiN doped in situ with oxygen.
2009
International audience; Incorporation of oxygen into TiN lattice results in formation of titanium oxynitrides, TiOxNy that have become particularly interesting for photocatalytic applications. Elaboration as well as characterization of TiN and in situ oxygen-doped thin films is the subject of this paper. Thin films, 250–320nm in thickness, have been deposited by dc-pulsed magnetron reactive sputtering from Ti target under controllable gas flows of Ar, N2 and O2. Optical monitoring of Ti plasma emission line at = 500nm has been implemented in order to stabilize the sputtering rate. Scanning electron microscopy (SEM), X-ray diffraction in grazing incidence (GIXRD), micro-Raman spectroscopy, X…
Anisotropic and non-heterogeneous continuum percolation in titanium oxynitride thin columnar films
2002
International audience; We report the percolation behaviour of the conductivity of titanium oxynitride films grown by low-pressure metal-organic chemical vapour deposition, composed of TiNxOy mixed with TiO2. The usual DC parameters (t, s and Φc), obtained from the effective media theory equations, are compared to the universal values (s = sun while t < tun because of the film anisotropy). This is the first example of an electrical continuum percolation applied to columnar films with chemically similar conducting and insulating units (non-heterogeneous percolation) whose mixing is based upon the growth temperature during the film growth.
Pulsed Direct liquid Injection ALD of TiO2 Films Using Titanium Tetraisopropoxide Precursor
2013
Abstract TiO 2 thin films are grown by pulsed direct liquid injection atomic layer deposition with rapid thermal heating using titanium tetraisopropoxide and water vapor as precursors. The ALD growth rate is constant in the saturation zone range 35-47 ms at the temperature deposition of 280 °C. The TiO 2 growth rate of 0.018 nm/cycle was achieved in a self-limited ALD mode. SEM and AFM analysis showed the as-deposited films have a smooth surface with a low roughness. XPS analysis exhibited the stoichiometry of TiO 2 in the homogenous depth composition.
Influence of sol counter-ions on the visible light induced photocatalytic behaviour of TiO2 nanoparticles
2014
Titanium dioxide (TiO2) nanoparticles are attracting increasing interest because of their superior photocatalytic and antibacterial properties. Here, aqueous titanium oxy-hydroxide sols were made, using a green synthesis method, from the controlled hydrolysis/peptisation of titanium isopropoxide. Three different mineral acids were used to peptise the sol (HNO3, HBr and HCl), and provide counter-ions. The influence of nitrate or halide sol counter-ions on size distributions of the starting sols were measured via photon correlation spectroscopy (PCS). Semi-quantitative phase composition analysis (QPA), on the gels thermally treated at 450 and 600 degrees C, was carried out via Rietveld refine…
Friction and wear of lubricated M3 Class 2 sintered high speed steel with and without TiC and MnS additives
2005
Abstract M3/2 sintered high speed steel and composite materials processed by initial admixing of 5 wt.% TiC (to decrease wear) and 5 wt.% MnS (to minimise friction) powders, singly and in combination, were assessed in pin-on-disc tribometers specially constructed to simulate use in the automotive valve train. Pins were of the sintered materials and the mating tribological material discs of T1 high speed steel. For comparison with existing conventional materials, identical tests were performed with discs and pins of two types of spheroidal cast iron. Testing at ∼110 °C, employing a few drops of fresh Shell Helix Standard SAE: 15W-40, API: SJ/CF oil, in daily segments of 5000 m of sliding dis…
Prediction of phase transformation of Ti-6Al-4V titanium alloy during hot-forging processes using a numerical model
2013
In this article numerical model for prediction of phase evolution of Ti-6Al-4V titanium alloy was presented. In particular, attention was focused on alpha to beta and beta to alpha+beta phase transformations. The analysis was conducted using a commercial implicit finite element method code, considering the data and the parameters of a real case study to check the quality of the numerical model. The alpha to beta transformation was developed using the simplified form of the Avrami model and the beta to alpha+beta transformation was controlled through the generalized Avrami model. The model so-thought has been used to conduct a 2D simulation of a forging process. A comparison between the num…
Scandium-44: Benefits of a Long-Lived PET Radionuclide Available from the 44Ti/44Sc Generator System
2011
(44)Ti/(44)Sc radionuclide generators are of interest for molecular imaging. The 3.97 hours half-life of (44)Sc and its high positron branching of 94.27% may stimulate the application of (44)Sc-labeled PET radiopharmaceuticals. This review describes the current status of (44)Ti production, (44)Ti/(44)Sc radionuclide generator development, post-processing of generator eluates towards medical application, identification of ligands adequate to Sc(III) co-ordination chemistry, proof-of-principle labeling of (44)Sc-DOTA-octreotides, investigation of in vitro and in vivo parameters, and initial applications for molecular imaging - both in small animals and humans.