Viability and Proliferation Assessment of Gingival Fibroblasts Cultured on Silver Nanoparticle-Doped Ti-6Al-4V Surfaces.

Purpose: To investigate the biocompatibility of silver nanoparticle (AgNP)-doped Ti-6Al-4V surfaces by evaluating the viability and proliferation rate of human gingival fibroblasts (HGFs)-as the dominant cells of peri-implant soft tissues-seeded on the modified surfaces.

Materials And Methods: AgNPs (sizes 8 nm and 30 nm) were incorporated onto Ti-6Al-4V specimen surfaces via electrochemical deposition, using colloid silver dispersions with increasing AgNP concentrations of 100 ppm, 200 ppm, and 300 ppm. One control and six experimental groups were included in the study: (1) control (Ti-6Al-4V), (2) 8 nm/100 ppm, (3) 8 nm/200 ppm, (4) 8 nm/300 ppm, (5) 30 nm/100 ppm, (6) 30 nm/200 ppm, and (7) 30 nm/300 ppm.

Airborne Pb, Si, Zn and Pb as tracers for atmospheric pollution in Helsinki metropolitan area.

This study analyzed 16070 daily and 608 weekly air filter samples from the Helsinki metropolitan area collected between 1962 and 2005. The aim was to use the Potential Source Contribution Function (PSCF) to determine potential sources of silicon (Si), zinc (Zn), lead (Pb), and radioactive isotope Pb. The main sources for Si and Pb were industrial activities, particularly mining, metal industry, and traffic.

Removal of Bromine from Polymer Blends with a Composition Simulating That Found in Waste Electric and Electronic Equipment through a Facile and Environmentally Friendly Method.

The increasing volume of plastics from waste electric and electronic equipment (WEEE) nowadays is of major concern since the various toxic compounds that are formed during their handling enhance the difficulties in recycling them. To overcome these problems, this work examines solvent extraction as a pretreatment method, prior to thermochemical recycling by pyrolysis. The aim is to remove bromine from some polymeric blends, with a composition that simulates WEEE, in the presence of tetrabromobisphenol A (TBBPA).

Effect of different zirconia surface pretreatments on the flexural strength of veneered Y-TZP ceramic before and after in vitro aging.

Purpose: The investigation of zirconia core surface pretreatments on the flexural strength of bilayered zirconia ceramics before and after artificial accelerating aging.

Methods: Ninety bar-shaped specimens were manufactured from Yttria Stabilized Tetragonal Zirconia Polycrystal (Y-TZP) and divided in three groups depending on zirconia surface pretreatment before veneering: layering with liner, pretreatment with silane-containing gas flame (SGF) with the Silano-Pen device and alumina air-abrasion. Half of the veneered specimens in each group (n=15) underwent artificial accelerating aging.

Effect of brominated flame retardant on the pyrolysis products of polymers originating in WEEE.

Chemical recycling is an environmentally friendly method, which is often used for the recycling of plastics included in waste electric and electronic equipment (WEEE), since fuels and secondary valuable materials can be produced. Brominated flame retardants (BFRs) are usually added into these plastics to reduce their flammability; but they are toxic substances. The aim of this work is to examine the thermal behaviour and the products obtained after pyrolysis of polymer blends that consist of acrylonitrile-butadiene-styrene (ABS), high-impact polystyrene (HIPS), polycarbonate (PC) and polypropylene (PP) with composition that simulates real WEEE, in the absence and presence of a common BFR, tetrabromobisphenol A (TBBPA), in order to investigate its effect on pyrolysis products.

Novel Femto Laser Patterning of High Translucent Zirconia as an Alternative to Conventional Particle Abrasion.

Background: currently applied surface treatments for zirconia bonding may create undesired microcracks and surface flaws. The aim of the present study was to evaluate the efficacy of alternative surface treatments on the shear bond strength of high translucency zirconia to 10-Methacryloyloxydecyl dihydrogen phosphate (MDP)-containing resin-based cement.

Methods: fifty disk-shaped specimens (10 mm × 5 mm) were fabricated from a commercial yttria-stabilized zirconia with 5 mole% yttrium oxide tetragonal zirconia polycrystal (5Y-TZP), and underwent air-abrasion with alumina particles (50 μm-AL50 and 90 μm-AL90), glass beads (GB 10-60 μm), and ablation with femtosecond laser (FEMTO).

Synthesis and Characterization of Mesoporous Mg- and Sr-Doped Nanoparticles for Moxifloxacin Drug Delivery in Promising Tissue Engineering Applications.

Mesoporous silica-based nanoparticles (MSNs) are considered promising drug carriers because of their ordered pore structure, which permits high drug loading and release capacity. The dissolution of Si and Ca from MSNs can trigger osteogenic differentiation of stem cells towards extracellular matrix calcification, while Mg and Sr constitute key elements of bone biology and metabolism. The aim of this study was the synthesis and characterization of sol-gel-derived MSNs co-doped with Ca, Mg and Sr.

The effect of different aging protocols on the flexural strength and phase transformations of two monolithic zirconia ceramics.

Introduction: The aim of the present study was to investigate how different aging protocols can affect the flexural strength and phase transformations of yttrium-stabilized zirconia ceramics (Y-TZP) for monolithic restorations.

Materials And Methods: Bar-shaped specimens from two zirconia ceramics bars were divided into three groups: a. no treatment (c), b.

Mechanical and thermal properties of PMMA resin composites for interim fixed prostheses reinforced with calcium β-pyrophosphate.

Interim restorations are essential in fixed prosthodontics as they provide temporary protection of teeth before the insertion of the permanent restoration. Poly(methyl methacrylate) (PMMA) is widely used in the fabrication of interim-fixed restorations as it is a biocompatible material with a lot of convenient properties. However, it exhibits low impact and tensile strength and therefore it is necessary to be reinforced.

Design, characterisation and drug release study of polymeric, drug-eluting single layer thin films on the surface of intraocular lenses.

To design, develop and study a novel drug delivery system for intraocular applications. The spin coating technique was applied to develop a polymeric, drug-eluting thin film consisting of a blend of organic polymers [poly (D, L lactide coglycolide) lactide: glycolide 75: 25, PLGA and polycaprolactone, PCL] and dexamethasone on the surface of intraocular lenses (IOLs). The initial durability of the IOLs during spinning was assessed.

Morphological and geochemical characterization of the particulate deposits and the black crust from the Triumphal Arch of Galerius in Thessaloniki, Greece: Implications for deterioration assessment.

In the present study, 12 particulate deposits and one black crust sample were collected from the Triumphal Arch of Galerius in Thessaloniki, Greece and characterized by employing a multi-analytical approach including chemical analysis of trace elements and ionic species, as well as scanning electron microscopy coupled with energy dispersive X-ray spectrometry (SEM-EDS) to gain information about the micromorphology and the chemical composition in terms of major elements. In addition, one unaltered marble sample, e.g.

In vitro assessment of oral and respiratory bioaccesibility of trace elements of environmental concern in Greek fly ashes: Assessing health risk via ingestion and inhalation.

Fly ash engender significant environmental and human health problems due to enhanced contents of potentially harmful trace elements (TrElems). This study aims to evaluate human exposure to TrElems via a combined ingestion (i.e.

Effect of ethanol/TEOS ratios and amount of ammonia on the properties of copper-doped calcium silicate nanoceramics.

Calcium magnesium silicate glasses could be suggested for the synthesis of scaffolds for hard tissue regeneration, as they present a high residual glassy phase, high hardness values and hydroxyapatite-forming ability. The use of trace elements in the human body, such as Cu, could improve the biological performance of such glasses, as Cu is known to play a significant role in angiogenesis. Nano-bioceramics are preferable compared to their micro-scale counterparts, because of their increased surface area, which improves both mechanical properties and apatite-forming ability due to the increased nucleation sites provided, their high diffusion rates, reduced sintering time or temperature, and high mechanical properties.

In vitro evaluation of the shear bond strength and bioactivity of a bioceramic cement for bonding monolithic zirconia.

Statement Of Problem: Adhesive cementation is the most common bonding strategy for zirconia restorations. Although cementation with a bioactive luting agent has been proposed as an alternative, how the bond strength compares is unclear.

Purpose: The purpose of this in vitro study was to evaluate shear bond strength after cementing a monolithic zirconia ceramic to human dentin with a bioceramic cement, compare it with a traditional cement, and evaluate its bioactive properties.

Evaluation of the biological behaviour of various dental implant abutment materials on attachment and viability of human gingival fibroblasts.

Objective: This study aimed to investigate the biological effects of yttria-stabilized zirconia (Y-TZP) compared to other dental implant abutment materials, i.e. lithium disilicate (LS2) and titanium alloy (Ti), as well as the effects of aging of Y-TZP on viability/proliferation and attachment properties of Human Gingival Fibroblasts (HGFs).

Natural radioactivity studies in a paleontology site and paleoclimate interpretation of the last 8 Mya.

Fossil bones and sediments from different horizons of the Upper Miocene paleontological site of Platania, Drama-Greece were studied using U, U, Th series and K measurements obtained by γ-spectroscopy. Additionally, SEM and XRF analysis was applied to bone and sediment samples while a lithological analysis of the sediments was also carried out. The Ra/U ratios in the fossilization layers are attributed to the U depletion from the sediment and its incorporation into the fossils.

Evaluation of the micro-mechanical and bioactive properties of bioactive glass-dental porcelain composite.

The aim of this study was to evaluate microhardness and elastic modulus of a novel sol-gel derived dental ceramic - 58S bioactive glass composite (BP67: Bioactive Glass:33.3%, Dental Ceramic:66.7%) BP67 material by micro-indentation and to investigate its microstructure and bioactivity.

Bactericidal and Bioactive Dental Composites.

Antimicrobial and bioactive restorative materials are needed to develop a bacteria free environment and tight bond with the surrounding tissue, preventing the spread of secondary caries and thus extending the lifetime of dental restorations. The characteristic properties of new dental bioactive and antibacterial composites are presented in this work. The new composites have been microstructurally characterized and both long and short term properties have been studied.

Color stability of lithium disilicate ceramics after aging and immersion in common beverages.

Statement Of Problem: The color of an esthetic restoration and its color stability are important for long-term success. However, the impact of common beverages on lithium disilicate ceramic is not well known.

Purpose: The purpose of this in vitro study was to investigate color variations of lithium disilicate ceramics after thermocycling (TC) and immersion in commonly consumed beverages.

Magnetic signature, geochemistry, and oral bioaccessibility of "technogenic" metals in contaminated industrial soils from Sindos Industrial Area, Northern Greece.

The objective of this study was to assess the contamination level of potentially harmful elements (PHEs) in industrial soils and how this relates to environmental magnetism. Moreover, emphasis was given to the determination of the potential mobile fractions of typically "technogenic" metals. Therefore, magnetic and geochemical parameters were determined in topsoils (0-20 cm) collected around a chemical industry in Sindos Industrial Area, Thessaloniki, Greece.

Reinforcement of a PMMA resin for interim fixed prostheses with silica nanoparticles.

Purpose: Fractures in long span provisional/interim restorations are a common complication. Adequate fracture toughness is necessary to resist occlusal forces and crack propagation, so these restorations should be constructed with materials of improved mechanical properties. The aim of this study was to investigate the possible reinforcement of neat silica nanoparticles and trietoxyvinylsilane-modified silica nanoparticles in a PMMA resin for fixed interim restorations.

An experimental bioactive dental ceramic for metal-ceramic restorations: Textural characteristics and investigation of the mechanical properties.

The aim of this study was the evaluation of the textural characteristics of an experimental sol-gel derived feldspathic dental ceramic, which has already been proven bioactive and the investigation of its flexural strength through Weibull Statistical Analysis. The null hypothesis was that the flexural strength of the experimental and the commercial dental ceramic would be of the same order, resulting in a dental ceramic with apatite forming ability and adequate mechanical integrity. Although the flexural strength of the experimental ceramics was not statistically significant different compared to the commercial one, the amount of blind pores due to processing was greater.