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The aim of this study was to compare the evaluation of two groups of denture wearers following specific parameters at 6 and 12 month after the treatment..The study group included 15 patients with Cr-Co alloy skeletal dentures with metallic crowns with distal occlusal clasps and the base of methyl polymethacrylate (PMMA) and 15 with partially flexible dentures made of super-nylon polyamide resin. Based on the evaluation of these dentures, the 7 clinical parameters stated, over a period of 18 months and within the limits of this study, it can be concluded that partial removable dentures made of nylon-Valplast superpolyamide can be considered as a viable option to Cr-Co alloy.

The paper presents the obtaining, characterization and testing of a new type of polyelectrolyte based on acrylamide (2.63 mol/L), acrylic acid (1.73 mol/L) and sodium alginate (4.63x10-3 and 9.26x10-3 mol/L), for flocculation purposes. Two types of monomeric solutions were irradiated in electron beam at room temperature and in atmospheric conditions with doses between 0.5 and 2 kGy using ALID 7 linear electron accelerator of 5.5 MeV. The potassium persulfate (9.25x10-4 mol/L) was used as reaction initiator in both types of solutions. The flocculants thus obtained were characterized using various physical and chemical methods in order to determine conversion coefficient, residual monomer content, intrinsic viscosity, grafting ratio and grafting efficiency. The flocculation efficiency was evaluated in 0.1 and 0.2 wt % blue kaolin suspension at room temperature using a standard Jar test apparatus.

In order to evaluate the behavior in various electrical applications, the main mechanical and electrical characteristics of three different varieties of specifically chosen lacquers - based on alkyl-epoxy-melamine copolymer, the epoxy polymer and polyurethane were compared. From the mechanical determinations, it was found that at ambient temperature the polyurethane lacquer bending resistance was approximately equal to that of the epoxy lacquer and about 6.5 times higher that of the alkyl-epoxy-melamine copolymer. It has also been shown that at bending force of less than 150 Nm the investigated polyurethane lacquer has relatively large deformations of 0.4 mm / kN, which indicates a high capacity to take over relatively high deformations of the metal support (due to thermal expansion from various applications) without significant increasing mechanical stress. The recorded values for the alkyl-epoxy-melamine-based copolymer lacquer and the pure epoxy lacquer are 0.11 mm / kN and 0.03 mm / kN respectively. Determinations by dielectric spectroscopy have shown that at frequencies below 250 Hz the dielectric losses tgd for the epoxy and polyurethane lacquers are approximately equal and are about 2.9 times lower than for the alkyl-epoxy-melamine copolymer lacquer. It was also found that at frequencies higher than 250 Hz the investigated materials behave differently, respectively at the frequency increase up to 10 kHz, the dielectric loss tgd of the polyurethane lacquer remains constant at about 0.0045 in contrast to the epoxide lacquer at which the dielectric loss tgd increases monotone to 0.0095 at 10 kHz, respectively of the alkyl-epoxy-melamine copolymer at which the dielectric loss tgd is approximately constant 0.012 in the 250 Hz-10 kHz range.

The products used in cosmetic formulations are continuously diversifying as a result of researches in the field, which combine the healing and prevention of many skin conditions with the use of natural products such as vegetable extracts and essential oils. Testing the stability and compatibility of new or modified cosmetics is required to ensure that quality standards are met when stored in proper conditions for functionality and aesthetics, to preserve their chemical, microbiological and physical properties. In this study, the stability and compatibility of a new cosmetic product containing lavender essential oil in plastic container-plastic jar 100 mL PPH Polypropylene homopolymer (Moplen HP648T) is tested against the glass receptacle used as a control. The monitored parameters were organoleptic characteristics (appearance, color, fragrance), physicochemical (pH, density), under controlled temperature conditions, and the microbiological ones. The results of this study showed that the tested cosmetic product is compatible with the plastic container; data obtained were comparable with the organoleptic and physicochemical test results obtained in the case of the control sample stored at room conditions.

Purpose of the articleto carry out an epidemiological study on the use of sealing as a method of preventing dental caries and to assess the tightness and integrity over time of composite resins used to seal pits and fissures using the VistaCam iX intraoral fluorescence camera. Based on the premise that dentists do not have enough confidence in sealing pits and fissures as a method of preventing dental caries, we assessed if sealing is used in current practice as a prevention metod of tooth decay, and we measured, with high performance intraoral camera such as the VistaCam iX device, the tightness and integrity of composite resin seals.

The aim of this study was to compare the biofilm formation on three types of dental crown materials using adenosine triphosphate (ATP) driven bioluminescence as an innovative tool for the rapid chairside enumeration of oral bacteria and assessment of oral hygiene. The study group included 60 patients with fixed prosthodontics, made of three types of dental crown materials (BioHpp - Bredent, Ceramics - VITA VMK Master, and Zirconia - Vita In-Ceram) from which we have collected 60 specimen values using a luciferase-based assay system (system SURE II). The values of ATP were obtained with System SURE II device and statistically analyzed with Anova and Wilcoxon Test. The lowest value was shown for Zirconia, comparing with ceramics and BioHpp, but in time we have seen the increase of ATP for all three dental crown materials.

In the last years, health care professionals faced with an increasing number of patients suffering from wounds, burns and bedsores difficult to treat and heal. During the wound healing process, the dressing protects the injured area and contributes to the recovery of dermal and epidermal tissues. Because their biocompatibility, biodegradability and similarity to macromolecules recognized by the human body, some natural polymers such as polysaccharides (alginates, chitin, chitosan), proteoglycans and proteins (collagen, gelatin, fibrin) are extensively are used in wounds and burns management. The study presents a research of new semi-solid formulations of bio-composites based on chitosan extracted from the stone crab Pachygrapsus Mormoratus found on the Black Sea shores. The bio-composites were obtained from natural polymeric compounds, Chitosan (CT), hyaluronic acid (HA) and lanolin(L), to which silver sulfadiazine (S), was added. Several semi-solid formulations have been performed for which the antimicrobial activity on gram-positive and gram-negative germ cultures and the rheological behavior was studied. The bio-composites that were obtained provide an optimal micro-environment for cell proliferation, migration and differentiation, due to their biocompatibility, biodegradability, peculiar structure and good antimicrobial activity.

The paper treats Finite Element Analysis (FEA) specific to the mechanical behavior of a structural layer cap type with polymer cellular cores within a pressure vessel. The layered composite structure comprises two outer polymer shells (synthetic glass/ plexiglass) and cellular polymer core with triangular shaped cells. This analysis uses the Autodesk Inventor 2016 Professional 3D design and modeling software, in conjunction with the FEA analysis program, ANSYS 14.5 - Workbench, using the Mesh module. Mechanical behavior of the structural models specific to the four types of test caps, each having different cellular polymer core (ABS, PLA, PC and CF, 3 and 5 mm thickness), is revealed through the analysis of the state of stresses and deformations and correlating the FEA simulation results with experimental testing. Since the analysis leads to quasi-equivalent results under identical conditions of application until the fracture of the caps, it is found that such an FEA approach of the mechanical system components occupies an important place in the modern design process, being one of the ways of identifying the deformation fields and equivalent stresses in the analyzed composite structures.

This paper presents the solvents effect on the mechanical and thermal properties of films of styrene-butadiene and styrene-isoprene block copolymers with the majority diene phase, obtained by spin casting.

The article presents the process of manufacturing by adding solid state material (thermoplastic extrusion) in order to achieve new composite deposition materials and to provide new models, raw materials and functional prototypes with superior mechanical features and characteristics. The authors describe the extrusion device as well as the parts manufactured of thermoplastic material.