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FDM is 3D printing technology using mainly PLA and ABS as filament materials. PP has close characteristics to PLA and, due to that, is a potential material for for deposition. Paper aims to analyse the behaviour of PP during heating cycle specific to 3D printing process. Macroscopic and microscopic analysis of the deposited strings have been performed. They revealed less stiffness of the PP deposition comparing to PLA, which is due to the lower viscosity of PP. DSC Thermal analysis has been done at it revealed a 30% higher heat flux in PP comparing to PLA and that increases its fluidity. It was recorded a difference between the elongation viscosity of the PP filament and the PP deposited by FDM process. After 5s the deposited PP proves higher values for the elongation viscosity. Dynamic shear rheology measurements the was applied on samples deformed under 210 kN at 190oC. It has been found that the PP requires lower storage energy and that means that it has a lower viscosity for the entire range of applied frequencies. In the same time, the complex viscosities prove different behavior. To improve the control of the deposition shape, it is necessary to reduce the extrusion temperature with 4-5%. That leads to economy in power consumption.

PLGA (poly-lactic-co-glycolic acid) nanoparticles represent an important synthetic biocomponent that has the potential to be a promising carrier of drugs, proteins, nucleic acids, due to its biodegradability and minimal side effects. The aim of our study was to observe the antioxidant effect of vitamin E loaded in PLGA nanoparticles administered over a period of 3 weeks in Wistar rats treated with a hypercaloric diet. Glutathione (GSH) and malondiadehyde (MDA) biomarkers determined from liver lysate were analyzed to evaluate the oxidative stress (OS) induced by the hypercaloric diet. The results of our study revealed a statistically significant increase for GSH and vitamin E in group 2 of Wistar rats receiving hypercaloric diet and a daily dose of vitamin E versus group 1 (p[0.005). The antioxidant effect of vitamin E was also observed by the statistically significant decrease of MDA in group 2 of Wistar rats compared with group 1. The daily dose of vitamin E has improved the liver redox status of group 2 Wistar rats.

The paper presents an analysis regarding the use of ERTALON 4.6 polyamide in high thermal shock systems. The behavior of ERTALON 4.6 polyamide mounted on high thermal shock systems was studied using high speed thermal imaging cameras. In the same time its mechanical proprieties were studied with the purpose to determine if it can withstand the stresses that occur during rifle firings.

Treatment of crown root fracture is complex and requires an accurate diagnostic and treatment plan. The purpose of this article is to report a case of a maxillary central incisor with a crown-root fracture with pulp exposure treated and rehabilitated with the preservation of pulp vitality using a micro-pulpotomy and pre-mixed bioactive endodontic cements followed by zirconia restauration, a bioinert ceramic material, milled using CAD/CAM technology. The preservation of pulp vitality using premixed bioceramic materials, ensures the continuation of dentinogenesis with its benefits, higher resistance of radicular walls against fracture, smaller diameter of apical foramen as well as creating conditions over time for a post retained crown with better aesthetic results.

The thermochemical stability of a MOL (mineral oil) electroinsulating mineral oil was studied by the gas chromatography technique, compared with a Voil (vegetable oil) electroinsulating fluid based on natural esters (oil), exposed to a longer (1000 hours) thermal treatment (110 ± 5 °C) in contact with the core transformer plate (silicon steel sheet) both blank and covered by immersion with three different types of lacquers (L-G epoxide, L-528 alkyl epoxy-melamine copolymer and L-S polyurethane). Experimentally it was noted that during the thermal treatment applied and in contact with the silicon steel sheet, the investigated oils have produced mainly C2H4, CH4 and H2. The total amount of flammable gases formed in Voil (vegetable oil) is about 7.5 time lower than in MOL. It has also been found that the lacquer coating of the silicon steel sheet does not change the mechanism of gas formation processes in the investigated oils, as well as the fact that the oxygen content of the investigated oils decreases monotonously during the thermal treatment applied due to either the formation of CO2 and CO and the oxidation processes of investigated lacquers.

The article presents a promising technology for medical applications - additive technology by thermoplastic extrusion. Some conceptual models for knee prostheses of different constructional forms have been made using FDM technology. Different materials, including biocompatible, were considered and different 3D printing equipment was used to choose the variant with the most optimal characteristics. These conceptual models can have various beneficial applications in medicine, improving the quality and functionality of personalized prostheses.

Periodontal diseases are inflammatory diseases that cause lesions of the dento-periodontal system and can even lead to the loss of teeth. A successful treatment of periodontal diseases includes procedures aimed at reducing inflammation, by mechanical and chemical means, which have the role to decrease the pathogenicity of microorganisms found in the bacterial plaque. The study was conducted on a group of 50 patients, of whom a control group of 25 patients followed conventional periodontal treatment, while the other 25 patients received magnesium-terpene therapy by using polymeric thermoforming mouth custom trays, along with conventional periodontal treatment. The statistical and clinical assessment of the study revealed the efficiency of the magnesium-terpene active gel for the treatment of periodontal disease.

Patients with total atrioventricular block are of particular interest and prone to severe prognosis unless treated with emergency cardiac pacing. We evaluated different types of leads and their impact on the myocardium, according to the fixation type and pacing method.. A pacemaker patient has a different depolarization pattern and a single chamber pacemaker, has by definition, an intracardiac desynchronization and a different electro-mechanical coupling activity. The presence of late potentials is an independent prognosis factor for cardiac death and electrical vulnerability, especially after myocardial infarction(MI). Late potentials recorded as magnitude vector are the expresion of late depolarization of the surrounding tissue and represent the morfological substrate for reentry. Thus, the incidence of late potentials after pacemaker implant, represents the expresion of electrical vulnerability of the stimulated right ventricular myocardium. In order to deeply study the parameters of magnitude vectors, we noticed the appearance of late potentials during the transitory stimulation in acute atrioventricular block and a restoration of vector normal parameters, after conduction recovery and sinus rhythm conversion.

A bone defect with standard dimensions and localization is produced. Inside this defect a polymer (collagen sponge) impregnated with growing factors, i. e. bone morphogenetic protein – BMP, is introduced. For the witness lot, the same defect is produced, in which the same polymer is introduced, but without any growing factors. It is found that the growing factor not only remains at the initial site, but also has effect on the bone regeneration process. A mathematical model is constructed using a field theory of multifractal type based on the spontaneous symmetry breaking mechanism to exploit such dynamics in biostructures. This mechanism contains all the informational “ingredients”: the multivalent logic based multifractal bit, the algorithm based networks through spatial cnoidal modes of oscilation, etc. In such context, the evolution of all biostructures, through a mechanism that mimics a 3D biological printer, can become operational.

Sutures are classified into non-absorbable and absorbable, and mechanical properties of these materials vary by the composition. In this study we analyze four different types of sutures used commonly in surgery: silk, nylon, polyglycolic acid (PGA) and polytetrafluoroethylene (PTFE). The materials were chosen to represent a wide range of suture material categories: absorbable and nonresorbable, monofilament and multifilament, natural and synthetic in order to assess their mechanical properties but also the bacterial adherence to each type. The objective of this study was to measure the total bacterial adherence by using real time PCR at 7 days postop and to analyze the antibacterial and mechanical properties comparatively depending on the type and composition of sutures. Tensile properties such as maximum tensile load, elongation rate, stiffness and energy absorbed before breakage were taken into consideration. Experimental determination pointed out that the average total bacterial load was lowest for PTFE and highest for silk. The results of the study are useful in choosing an appropriate suture wire according to the mechanical properties taking into account the bacterial load of the surgical site in order to aid in tissue repair.