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The current trend is the introduction of antimicrobial agents for the purpose of inhibiting or avoiding (adherence) adhesion and (increasing) the multiplication of their microorganisms on the surface of the impression materials. This study aims to determine the properties of antibacterial and antifungal elastic impression materials in full agreement with (bacterial flora) microflora specific for every patient ( with identification of existing species ). In the same time there are considered modern methods of sterilization and insertion of antiseptics, trajectories with profound impact in the field of biocompatibility. The obtained microorganisms were transplanted on differentiated and selective (differentiated) culture medium in order to obtain pure cultures.Each microbial strain obtained was tested to identify several characteristics. The examinations carried out by means of the electron microscopy very accurately detect the microbial load in the structure of the impression materials, sounding an alarm signal on its use in particular clinical situations. Alginates present in their structure polysaccharide structures that represent an excellent substrate of microorganisms.

The developement and regeneration of healthy bone tissue is a complex process that includes the interaction of different cell types and requires a set of coordinated processes. The loss of bone tissue may occur due to various reasons: surgical removal, bone trauma (i.e., fractures) or systemic bone loss (i.e., osteoporosis). When the natural bone tissue is destroyed, the regeneration capacity of the bone is not always satisfactory. The result consists therefore in many functional and structural aberrations. In order to improve and accelerate the healing process, bone substitutes have been developed. Hydroxyapatite has been widely used in bone applications due to its excellent biocompatibility, osteoconductivity and bioactivity [1,2]. The objective of this research is to obtain a new composite biomaterial that can be used as bone substitute. In this study, bovine hydroxyapatite obtained from freshly calcined bovine femur was used. The objective of this research is to obtain a new composite biomaterial that can be used as bone substitute. The experimental composite samples were obtained using bovine hydroxyapatite as matrix and tricalcium phosphate, respectively, magnesium oxide as reinforcement materials. The synthesis process of these new biomaterial composites, the effect of chemical composition, surface structure, chemical and phase composition as well as mechanical features have been investigated.

The current study relates to the immobilization of the nasal region with splints using modern materials such as thermoplastic compounds in patients that have undergone rhinoplasty. The objectives of the research are to highlight the main characteristics of thermoplastic splints and to perform a comparative analysis in relation with traditional splints. The research was conducted on 2 batches, the first batch involving 24 patients that have undergone rhinoplasty, the postoperative immobilization being performed using metallic splints and the second batch involving 29 patients, thermoplastic splints being used for immobilization after the surgery. The results of the study are focused on evaluating both thermoplastic and traditional splints based on several criteria, such as modeling capacity, toxicity, surgical risks and patients’ degree of satisfaction.

Zinc oxide (ZnO) is an inorganic compound used for its antiseptic and skin healing properties. It is an excellent protective filter against UV radiation and it can be used as white pigment in pharmaceutical preparations. In this study, nano-ZnO particles were obtained by ultrasound treatment, and respectively by repeated freezing/heating process. The influence of synthesis method and of ultrasound generator parameters on the particles size and stability was observed. The results reveal that were obtained samples with a very good stability and sizes between 15 and 96 nm. It was found that synthesis based on ultrasound treatment lead to the formation of nanoparticles with lower sizes.

With technology becoming more and more advanced, the medical system is being consistently improved. From intraoral scanners that started to replace conventionally impressions technique to printed surgical guides that directs the drilling systems of implants, dentistry is one of the beneficiars of new and advanced treatments that are ergonomic, safe and put both the medical team and the patient in a more pleasant experience. The purpose of our article is to summarize the application of acrylic and metacrylic resin in 3D printing of surgical guides used in orthodontics.

Thermoplastic polymers have found widespread applicability in electronic industry owing to their facile processing and relatively low costs. Transparent polymer foils, like polyethylene terephthalate (PET), can be utilized in manufacturing components for liquid crystal display (LCD) devices. This work is focused on surface processing of PET through different procedures. The induced surface modifications of polymer samples were analyzed by optical microscopy. Contact angles of nematic drops on PET film are measured to evaluate how the method of surface modification reveals that the surface texturing affects the interactions of polymer with the liquid crystal. The influence of created surface anisotropy on the work of adhesion at polymer/liquid crystal interface is analyzed. Preliminary assessment of nematic orientation on the surface of modified PET foils is performed using polarized light. The results were discussed in regard with the used methodology to adapt the surface of the PET films to achieve optimal orientation of nematic molecules. The obtained data will open new perspectives on processing polymer foils as alignment layers used in LCD devices.

Abstract.The paper aims to present research on the determination of the coefficient of acoustic absorption as a function of frequency, for composite monolayer plates (made of: MDF - wooden dried agglomerated fibres with medium density, RWB – rebated wood from dried beech, PS - extruded polystyrene) and multilayer (with outer coatings of: MDF, RWB and polymeric core of extruded polystyrene). The sound-absorbing behavior of such plates is highlighted in the cabins made of multilayer structures.

In this study, a new solution for the development of an antiradar camouflage by overlaying several mono-pigment polymeric structures in a composite structure is provided. In this respect, powder materials with antiradar properties (carbon nanotubes, graphite, active charcoal, aluminum trioxide) were embedded in polymeric matrices. The performances of the developed products were tested using an experimental device for the measurement of electromagnetic efficiency within the frequency range from 1 to 18 GHz.

Lately, PP-R pipes have become increasingly popular in terms of drinking water installations and heating. Comparated to the classic pipes from copper or steel, pipes from propylene are much easier to use, they have obvious qualities and they are marketed at a much lower price. The study aims a comparative analysis of the physical-mechanical properties of the four most common types of pipes from propylene, which are currently found in commerce : simple without insertion(PP-R), with insert of composite fiber (PP-R-CF), with insert of basalt fiber (PP-R-BF) and with insert of aluminium (PP-R-AIF). Experimental research showed that from the point of view of thermal expansion, the best behavior is from the pipes from propylene without any insert and the value of the thermal expansion coefficient for the reinforcement pipe with basaltic fiber is very small. After these attempts at tensile, it resulted that all four samples which were analyzed from the point of view of the tensile strength, don’t exceed the limit that was given by the manufacturer (10-30 MPa), the values obtained being: for pipe from polypropylene of 17 MPa, for pipe from polypropylene with insert of aluminium of 18 MPa, for the test tube from pipe of polypropylene with insert of basalt fiber of 29 MPa and for the test tube from pipe of polypropylene with insert of composite fiber of 30 MPa. Therefore, from the point of view of the behavior at tensile and bending, the best behavior is from the pipes from polypropylene with insert of basalt fiber and pipes from polypropylene with insert of composite fiber.

Background. The macroporous polyurethane ether foam was introduced in the medical field, as early as the 90 ties, for the Vacuum-assisted closure (V.A.C.) of a wound. We describe our experience after treating abdominal wound dehiscence in a group of elderly gynecological patients with NPWT (Negative Pressure Wound Therapy), using ether foam coated with a silver layer. We reviewed elderly patients chart data that underwent abdominal surgery complicated with wound dehiscence treated with VAC for eighteen months. In all patients, the system used was the standard GranuFoam Silver™ dressing (different extents), which was usually replaced every 48/72 h. A total of 15 consecutive female patients were included. The median age was 67.3 (58-71) years. Duration of VAC treatment was median 14.2 (11-34) days, and we saw an improvement in wound repair but also clearance of S.S.I. on the third day after applying V.A.C. Ulta™. Definitive secondary closure of the wound was obtained in all patients, as the infection’s site clearance. The abdominal VAC treatment with GranuFoam Silver™ dressing in patients with infected abdominal wound dehiscence is safe and has proper patient compliance. The latest evolution of the silver foam polyether dressing, in conjunction with NPWT therapy, offers a better antimicrobial effect and shorter healing stage.