Objectives: Using dental Ti implants has become a well-accepted and used method for replacing missing dentition. It has become evident that in many cases peri-implant inflammation develops. The objective was to create and evaluate the antibacterial effect of silver nanoparticle (Ag-NP) coated Ti surfaces that can help to prevent such processes if applied on the surface of dental implants. Methods: Annealing I, Ag ion implantation by the beam of an Electron Cyclotron Resonance Ion Source (ECRIS), Ag Physical Vapor Deposition (PVD), Annealing II procedures were used, respectively, to create a safely anchored Ag-NP layer on 1x1 cm^2, Grade 2 titanium samples. The antibacterial effect was evaluated by culturing Staphylococcus aureus (ATCC 29213) on the surfaces of the samples for 8 hours, and comparing the results to that of glass as control and of pure titanium samples. Alamar Blue assay was carried out to check cytotoxicity. Results: It was proved that silver nanoparticles were present on the treated surfaces. The average diameter of the particles was 58 nm, with a 25 nm deviation and Gaussian distribution, the the filling factor was 25%. Antibacterial evaluation revealed that the nanoparticle covered samples had an antibacterial effect of 64.6% that was statistically significant. Tests also proved that the nanoparticles are safely anchored to the titanium surface and are not cytotoxic. Conclusion: Creating a silver nanoparticle layer can be an option to add antibacterial features to the implant surface and to help in the prevention of peri-implant inflammatory processes. Recent studies demonstrated that silver nanoparticles can induce pathology in mammal cells, thus safe fixation of the particles is essential to prevent them from getting into the circulation.

In this study, scaffolds were prepared via an electrospinning method for application in oral cavities. The hydrophilicity of the fiber mesh is of paramount importance, as it promotes cell spreading; however, the most commonly used polyvinyl alcohol (PVA) and other hydrophilic fiber meshes immediately disintegrate in aqueous media. In contrast, the excessive hydrophobicity of the scaffolds already inhibits cells adhesion on the surface. Therefore, the hydrophilicity of the fiber meshes needed to be optimized. Scaffolds with different polyvinyl alcohol (PVA)/chitosan/citric acid ratios were prepared. The addition of chitosan and the heat initiated cross-linkage of the polymers via citric acid enhanced the scaffolds’ hydrophobicity. The optimization of this property could be followed by contact angle measurements, and the increased number of cross-linkages were also supported by IR spectroscopy results. The fibers’ physical parameters were monitored via low-vacuum scanning electron microscopy (SEM) and atomic force microscopy (AFM). As biocompatibility is essential for dental applications, Alamar Blue assay was used to prove that meshes do not have any negative effects on dental pulp stem cells. Our results showed that the optimization of the fiber nets was successful, as they will not disintegrate in intraoral cavities during dental applications.

In this paper, the Atomki Accelerator Centre (AAC, Debrecen, Hungary) incorporating several small-sized particle accelerators is reviewed. The energy range of our accelerators for proton beam is between 50 eV and 20 MeV. The technical and personnel organization of AAC is presented together with the rules of beamtime requests and usage. Three of our accelerators (Cyclotron, ECRIS, Tandetron) are described in detail with their technical descriptions and with the main application fields. As an example for highlights, a series of unique low-energy ion–sample irradiations and post-treatments are shown which, by our hopes and plans, form a bridge between physics and biology.

It has been shown by the Auger depth profiling technique that the concentration profile at the initially sharp Si/Ge interface in amorphous Si/Ge multilayers shifted but remained still sharp after a heat treatment at 680 K for 100 h. At the same time the fast diffusion of Si resulted in the formation of an almost homogeneous Ge(Si) amorphous solid solution, while there was practically no diffusion of Ge into the Si layer. This is direct evidence on the strong concentration dependence of the interdiffusion coefficient in amorphous Si/Ge system, and it is in accordance with the previous indirect result obtained from the measurements of the decay of the small angle Bragg peaks, as well as with finite difference simulations.