Novel Magnetic Composite Materials for Dental Structure Restoration Application

In general, magnetic nanoparticles are not often used in dental applications due to some limitations of these materials, such as aggregation problems and low mechanical and chemical resistance but also esthetic problems due to their black color. Our research presents the synthesis of novel magnetic dental composite materials based on magnetic nanoparticles, functionalized and properly coated to overcome the limitations of using magnetic nanoparticles in dental applications. The composites were prepared using a preparation flow containing several integrated reaction steps used previously sequentially. An adequate and deep characterization of dental magnetic composites has been carried out in order to demonstrate that each limitation has been successfully overcome. It was proved that each component brings particular benefits in dental interventions: Fe3O4 nanoparticles have biocompatible, non-toxic properties and also antimicrobial effects; the SiO2 layer significantly increases the mechanical strength of the material; and the Ca(OH)2 layer initiates local calcification and significantly improves the color of the dental composite material. Due to magnetic properties, an innovative application approach on the tooth surface can be achieved under an external magnetic field, which, compared to conventional methods, has a major impact on reducing the occurrence of dental caries under filling materials as well as on reducing microfractures

Bioproductive parameters and fatty acids profile of the meat from broilers treated with flax meal and grape seeds meal

The 3-week feeding trial was conducted on 120, Cobb 500 chicks (14 days) assigned to two groups (C, E). Compared to C diet formulation (corn, wheat, soybean meal and flax meal as basic ingredients), E diet formulation also included 3% grape seeds meal as natural antioxidant. The feed intake and the gains were not significantly (P>0.05) different between groups. Six broilers/group were slaughtered in the end of the trial and 6 samples of breast and thigh meat/group were formed and assayed for the feeding value. The proportion of polyunsaturated fatty acids (PUFA) was significantly (P≤0.05) higher in group E than in group C, both for the chicken breast: 32.6±0.87g (E) vs 29.29±0.96 g/100 g total fatty acids (C), and in the thigh: 37.68±2.07g (E) vs 29.58±1.16 g/100g total fatty acids (C). The content of alfa linolenic acid (ALA) was significantly (P≤0.05) higher also in group E, both in the breast meat: 0.99±0.02g (E) vs 0.89±0.34g/100g total fatty acids (C), and in the thigh meat: 1.20±0.07g (E) vs 0.90±0.0g/100g total fatty acids (C). The omega-3 PUFA content was the highest in the breast meat sample, 2.19±0.07g/100g total fatty acids (E), with no significant (P>0.05) differences between groups

Dental Adhesive Interfaces Reinforced with Magnetic Nanoparticles: Evaluation and Modeling with Micro-CT versus Optical Microscopy

Dental adhesives are used in a wide range of applications, including to place direct composite restorations in frontal or posterior teeth. One of the most frequent causes for the failure of composite resin restorations is microleakages. The first aim of this work is to introduce a new type of self-etched dental adhesive doped with magnetic nanoparticles (MPs) synthetized in the laboratory. The scope is to produce adhesives with a minimized width/thickness to decrease the risk of microleakages. The second aim is to assess the width/thickness of the adhesive layer in all the characteristic areas of the teeth using both the less precise but most common optical microscopy and the more accurate and volumetric micro-Computed Tomography (CT) investigations. Twenty extracted teeth have been divided into four groups: Group 1 includes ‘blank’ samples with adhesives that are not doped with MPs; Group 2 includes samples with adhesives doped with MPs; Groups 3 and 4 include samples with adhesives doped with MPs that are subjected to an active magnetic field for 5 and 10 min, respectively. Microscopy investigations followed by micro-CT and EDAX are performed on the adhesive. While a rather good agreement is obtained between the microscopy and micro-CT results, the capability of the latter to offer a full volumetric reconstruction of the layer is exploited to analyze the adhesion of the four considered dental materials. Thus, from micro-CT results the graphs of the surface areas as functions of the adhesive layer width are modeled mathematically, as well as the volume of sealants, for each of the four groups. To our knowledge, it is the first time that such a methodology is used. Characteristic parameters are extracted and the ascertainment of the optimal parameter that should be utilized for such assessments is discussed. The study demonstrates the adhesion improvement produced for Groups 3 and 4, where MPs are used. It also concludes that the magnetic field should be applied to the adhesive material for the longest possible exposure time (with a trade-off with the clinical duration of the treatment)

Chapter 4: Iron-oxide Nanoparticle-based Contrast Agents

This chapter discusses the synthesis, functionalization, characterization, and imaging applications of iron-oxide-nanoparticle-based contrast agents. By reducing the size from bulk to the nanometer scale (\u3c20 nm), ferrimagnetic iron oxide acquires a magnetic property called superparamagnetism, which is key to the potential of these particles as MRI contrast agents. This chapter describes the theory governing the relaxivity of nanoparticle-based contrast agents. The different syntheses, coatings, and functionalization approaches are then discussed, including how these syntheses affect the properties of the nanomaterial. Different techniques for the characterization of the cores and coatings of nanoparticles, including their size and composition, are then discussed. Particular attention is given to characterization of the magnetic properties of iron oxide nanoparticles. Finally, the acquisition of MRI phantoms is presented