La mise en charge immédiate en réhabilitation orale implantaire

peer reviewedImmediate loading of oral implants is of great interest for dental practitioners because with this technique, the treatments are faster and the patients do not have to wear an uncomfortable removable provisional prosthesis. improvement of surgical protocols, brand of implants and surface topography makes this procedure reliable. a recent systematic review report a global survival rate of immediate loaded implants of 96,4% with a maximum follow up of 13 years

Electrochemical characterization of YSZ thick films deposited by dip-coating process

Yttria stabilized zirconia (YSZ, 8% Y2O3) thick films were coated on dense alumina substrates by a dip-coating process. The suspension was obtained by addition of a polymeric matrix in a stable suspension of commercial YSZ (Tosoh) powders dispersed in an azeotropic mixture MEK–EtOH. The suspension composition was improved by the addition of YSZ Tosoh particles encapsulated by zirconium alkoxide sol containing yttrium nitrate which are the precursors of the 8-YSZ oxide. This optimal formulation allowed preparing, via a dip-coating process, thick films which were, after thermal treatment, homogeneous, dense and crack-free. A specific method was performed to measure the electrical conductivity, i.e. to determine the ionic conductivity of the film: it uses the four-point probe technique combined with ac impedance spectroscopy. The good agreement between the classical two-electrode measurements performed on YSZ pellets and the four-electrode ones performed on YSZ films allows concluding that this method is relevant for characterizing the transport properties of thick films

Selective and Collaborative Optimization Methods for Plasmonics: A Comparison

International audienceIn this paper, we optimize the size parameters of hollow nanospheres and nanoshells used in cancer photothermal therapy and we focus on two practical therapy cases: the visible range for shallow cancer and the near infrared for deep cancer. For this, we consider analytical models: the Mie theory for coated spheres. The investigated optimization methods are the Evolutionary Method (EM) and the Particle Swarm Optimization (PSO) which are based on competitiveness and collaborative algorithms, respectively. A comparative study is achieved by checking the efficiency of the optimization methods, to improve the nanoparticles efficiency

Electromagnetic Heat-induced in Meso-structures: Computation of Temperature in Metallic Dimers

International audienceThe illumination of a dimer metallic nanostructure is known to produce an in- tense source of light, with nanometric size. This con¯nement of light in the gap between the two material structures can induce an increase of the absorption of the electromagnetic energy in the nanaoantenna itself, and therefore its warm-up. The multiphysics problem associated to this photo-thermal e®ect is modeled through a Finite Element Method (FEM). This contribu- tion consists in computing both the electromagnetic ¯eld and the temperature, and discussing the in°uence of the gap, in the case of a bow-tie nanoantenna. The applications could be the development of nanodevices with thermal properties

What was your fracture risk evaluated by FRAX® the day before your osteoporotic fracture?

Osteoporotic fracture (OF) is one of the major causes of morbidity and mortality in industrialized countries. Switzerland is among the countries with the greatest risk. Our aim was (1) to calculate the FRAX® in a selected Swiss population the day before the occurrence of an OF and (2) to compare the results with the proposed Swiss FRAX® thresholds. The Swiss Association Against Osteoporosis proposed guidelines for the treatment of osteoporosis based on age-dependent thresholds. To identify a population at a very high risk of osteoporotic fracture, we included all consecutive patients in the active OF pathway cohort from the Lausanne University Hospital, Switzerland. FRAX® was calculated with the available data the day before the actual OF. People with a FRAX® body mass index (BMI) or a FRAX® (bone mineral density) BMD lower than the Swiss thresholds were not considered at high risk. Two-hundred thirty-seven patients were included with a mean age of 77.2years, and 80% were female. Major types of fracture included hip (58%) and proximal humerus (25%) fractures. Mean FRAX® BMI values were 28.0, 10.0, 13.0, 26.0, and 37.0% for age groups 50-59, 60-69, 70-79, and 80-89years old, respectively. Fifty percent of the population was not considered at high risk by the FRAX® BMI. FRAX® BMD was available for 95 patients, and 45% had a T score < −2.5 standard deviation. Only 30% of patients with a normal or osteopenic BMD were classified at high risk by FRAX® BMD. The current proposed Swiss thresholds were not able to classify at high risk in 50 to 70% of the studied population the day before a major O

SERS detection of biomolecules using lithographied nanoparticles towards a reproducible SERS biosensor

International audienceIn this paper we highlight the accurate spectral detection of bovine serum albumin and ribonuclease-A using a Surface-Enhanced Raman Scattering (SERS) substrate based on gold nanocylinders obtained by Electron-Beam Lithography (EBL). The nanocylinders have diameter from 100 to 180 nm with a gap of 200 nm. We demonstrate that optimizing the size and the shape of the lithographied gold nanocylinders, we can obtain SERS spectra of proteins at low concentration. This SERS study enabled us to estimate high enhancement factors (105 for BSA and 107 for RNase-A) of important bands in the protein Raman spectrum measured for 1mM concentration. We demonstrate that to reach the highest enhancement it is necessary to optimize the SERS signal and that the main parameter of optimization is the LSPR position. The LSPR have to be suitably located between the laser excitation wavelength which is 632.8 nm and the position of the considered Raman band. Our study underlines the efficiency of gold nanocylinders arrays in spectral detection of proteins

Nanoshells for photothermal therapy: a Monte-Carlo based numerical study of their design tolerance

The optimization of the coated metallic nanoparticles and nanoshells is a current challenge for biological applications, especially for cancer photothermal therapy, considering both the continuous improvement of their fabrication and the increasing requirement of efficiency. The efficiency of the coupling between illumination with such nanostructures for burning purposes depends unevenly on their geometrical parameters (radius, thickness of the shell) and material parameters (permittivities which depend on the illumination wavelength). Through a Monte-Carlo method, we propose a numerical study of such nanodevice, to evaluate tolerances (or uncertainty) on these parameters, given a threshold of efficiency, to facilitate the design of nanoparticles. The results could help to focus on the relevant parameters of the engineering process for which the absorbed energy is the most dependant. The Monte-Carlo method confirms that the best burning efficiency are obtained for hollow nanospheres and exhibit the sensitivity of the absorbed electromagnetic energy as a function of each parameter. The proposed method is general and could be applied in design and development of new embedded coated nanomaterials used in biomedicine applications

Pegylated doxorubicin gold complex: From nanovector to potential intercalant agent for biosensor applications

We report an original approach to synthesize hybrid gold nanostructures in which doxorubicin (DOX), mixed to Poliethylenglycole diacid (PEG-COOH) led to original hybrid gold nanovector (DOX IN PEG AuNPs). In this work, we investigate the ability of DOX IN PEG-AuNPs to detect the amplification of the hybridization process by a sensitive Quartz crystal Microbalance with dissipation (QCM-D) by intercalation process. The sensing layer was carried out by self-assembled monolayer of β mercaptoethylamine (cysteamine) on gold-coated quartz crystal sensor composed by a rigid homobifunctional cross-linker 1,4 phenilenediisothiocyanate (PDITC) linked covalently with amino-probe oligonucleotides. By QCM characterization in the range from 8 µM to 20 nM, we demonstrate high specificity of DOX IN PEG-AuNPs-DNA with a limit of detection (LOD) of 9 nM. This result is very promising for development of sensitive and effective nanoparticle-based biosensor for quantifying small biomolecules concentration in physiological liquids. These results open a possibility to realize a new class of nanovector which will be tailored for different biomedical application, such as imaging, targeting and drugs delivery. Keywords: Quartz Crystal Microbalance (QCM), Chemical surface, DNA hybridization, Gold nanoparticles, Doxorubici

Electromagnetic Heat-induced in Meso-structures: Computation of Temperature in Metallic Dimers

International audienceThe illumination of a dimer metallic nanostructure is known to produce an in- tense source of light, with nanometric size. This con¯nement of light in the gap between the two material structures can induce an increase of the absorption of the electromagnetic energy in the nanaoantenna itself, and therefore its warm-up. The multiphysics problem associated to this photo-thermal e®ect is modeled through a Finite Element Method (FEM). This contribu- tion consists in computing both the electromagnetic ¯eld and the temperature, and discussing the in°uence of the gap, in the case of a bow-tie nanoantenna. The applications could be the development of nanodevices with thermal properties