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relied on conventional mechanical, anti-infective modalities, followed by a range of regenerative procedures. An innovative medical device, using thermoforming ethylene acetate base, with an electromagnetic applicator, homologated with CE mark in class 2a, was used in the treatment of second degree teeth mobility. The affected areas were exposed to a precise, totally atraumatic and noninvasive electromagnetic field. The preliminary study on 10 subjects was performed with this medical device, using a standard protocol of 30 exposures of 2 h each, on the affected area. Subjects were both male and female, aged between 20-70 years, in healthy state and having a good oral hygiene status. After 2 months, the results were recorded by testing the mobility of the affected teeth, by measuring the periodontal pockets depth and by comparing the radiographs effectuated before and after the treatment. The results were assessed and proved the appreciable reduction of teeth mobility, the reduction of periodontal pockets depth and bone regeneration in the regions exposed to the electromagnetic applicator. The conclusions of this preliminary study recommend this innovative medical device for the use in the healing of periodontal lesions as noninvasive and atraumatic therapy. Keywords: periodontal lesions, innovative medical device, healing

Alternative research techniques are essential in order to prove the efficacy of graphene dental materials and their viability, especially if we associate them with other materials studied so far. It is important to determine the effects of these techniques because they can demonstrate the viability and credibility of the research on its properties. The purpose of this study was to measure and analyze the mechanical properties of several composite materials with/without graphene and commercial composite Herculite, designed for dental composites restorations. The materials were composed of a visible light-curing monomer mixture (Bis-GMA+TEGDMA) as a matrix and hydroxyapatite with graphene, bioglasses, colloidal silica as a reinforcing filler. Ten specimens of different composites were prepared for each mechanical test: flexural strength, Young’s modulus, diametral tensile strength, and compressive strength test (Lloyd Instruments- LR5k Plus). Mean values and standard deviations were calculated and ANOVA and Student Newman Keuls multiple comparison tests were applied (P[ 0.05). The addition of 5-10 wt% of hydroxyapatite with graphene nanoparticles to the unfilled monomer mixtures led to the increase of both Young’s modulus, surface hardness of the material, and the flexural strength. Hydroxyapatite with graphene has been used as reinforcing nanofiller in polymeric materials, having potential applications for restorative composites. Keywords: graphene, hydroxyapatite, dental composites restoration, mechanical properties

Rubber is widely used in railway infrastructure and in rolling stock. Rubber pads are used in fastening systems of rail to sleepers and rubber elements are used in the primary suspension of Romanian (and foreign) electric locomotives, in freight and passengers railway cars, metro trains and trams; the trams wheels are built with rubber insertion in order to reduce the vehicle unsprung mass. Also, rubber elastic elements are used in railway vehicles buffers. From these examples it can be seen that the rubber elements are used in the construction of parts which are directly contributing to traffic safety. Keywords: rubber, railway car, suspension, railway safety

This paper is the first note on experimental protocol development regarding the use of Iosipescu test specimens with acrylic fibre insertion or without the insertion, with metal or textile fibres in a series of tests in which the structural and constructive characteristics of matrix biomaterials are optimised for removable prosthetic restoration. Tensile and shear tests allowed the determination of specimen consolidation with aluminium plates of clamping jaw heads. Based on the theoretical protocol, the following were determined: shape, size and loading of Iosipescu specimen and deck sizing. The CT-1 silicone adhesive behaviour was evaluated based on experimental data. Poly (methyl methacrylate), denoted as PMMA, was used in the study. PMMA has polyethylene fibre and copper wire mesh inserts. These were individually assembled using this adhesive that was used to fix aluminium plates on the clamping jaw heads. The values obtained for the maximum normal traction stress, smax ranged between 22 and 60 MPa, and the tangential shearing stress tmax, of the adhesive ranged between 2 and 6 MPa, with an average value of 4.75 MPa, both depending on the dimensional characteristics and structural composition of the specimens, thus confirming the role of stratification and inserts in the mechanical strength of the specimens. Stress values of smax and tmax allowed the determination of the dimensions of the surface the specimen clamping jaws are fixed upon, practical aspect influencing the accuracy of the final results. Keywords: Iosipescu test, silicon resin, poly (methyl methacrylate), removable prostheses

The goal of this study was to measure and analyze the water sorption and mechanical properties of 5 experimental flowable composites with different filling ratios and two types of initiation systems: self cured and light-cured. The samples were analysed, in order to observe the influence of initiation type and the amount of filler on the properties required to satisfy the conditions for dentistry use. We have determined the water sorption and mechanical properties (compressive strength, flexural strength, diametral tensile strength) according to ISO 4049/2000 and international norms “American Dental Association’s Specification No.27. The measurements were done using a mechanical testing machine Lloyd Instruments-LR5k Plus. Increased water absorption weakens the bonds in the polymer matrix, causing separation of filler by the polymer matrix, filler hydrolytically degrade, leading ultimately to reducing the mechanical resistance, which represents a major step in the characterization of dental materials to be used in dentistry. Among all the mechanical stress from oral cavity, the compression and the tension are the predominant forces, during which are developing the highest forces that dental hard tissues are subject to. The results of this study highlight the relationship between the composition, initiation system of the dental materials and their properties. Keywords: flowable dental composites, water sorption, compressive strength, flexural stiffness, tensile strength

IOL opacification is a growing issue reported lately in the speciality literature. [1-5] This article follows a series of retrospective cases regarding hydrophobic IOLs that were explanted from three different patients. The explants were examined using AFM and SEM (with EDS), in order to find more details about the surface morphology and the composition of the deposits. The results indicate that they are composed mainly of calcium and phosphate. The authors suggest that ocular comorbidity and other systemic factors are contributing to this complication. Keywords: IOL opacification, explanted IOL, surface deposits

The hepatic portal vein (HPV) is the central element of liver afferent pedicle. The intraparenchymal distribution of HPV determines the liver segmentation. The medial branches (MBs) serving left medial division (LMD) of the liver present the greatest morphological variability. On a total of 125 pieces of liver corrosion casts, one examined the intraparenchymal distribution of portal MBs and the segmentation of LMD. Regarding the intraparenchymal distribution of the branches in the LMD of the liver, we showed three distinct morphological types: Type I (81.6% of cases) where are present several small MBs with oblique downward trajectory; Type II (15.2% of cases) that has two distinct MBs, originating in the distal part of the PHV left branch, with slightly upward trajectory; Type III (3.2% of cases) that has three MBs, originating in the distal part of the PHV left branch, the higher with upward trajectory, the lower with downward trajectory, and the middle branch with variable trajectory and originated from the PHV left branch or in one of the first two MBs. Knowledge of this morphological types of portal MBs is important for clinical and surgical practice. Keywords: corrosion casts; hepatic portal vein; medial branches; variability; morphological typologies

The influence of the painting process on a biocompostable waste is studied. Disintegration degree (D %) of a 100% biocompostable plastic made from potato almidon is calculated for both painted and non -painted samples. Solid matrix is also characterized by means of a laboratory scaled composting process following UNE-EN norms [2, 3]. It can be concluded that painting has a negative influence on biocomposting process decreasing 4.48% disintegration degree. Average D% for painted samples is 84.56 %, and 89.04 for non- painted ones. Regarding to solid matrix, dry mass after composting is double (91.12 %) as before process (43.63 %) for painted samples and 91 % and 45.41 % after and before composting for non-painted samples. Volatile solids are reduced 5.17 % after composting for painted samples, and 8.78 % for non-painted. Organic nitrogen is reduced 0.34 % and 0.16% for painted and non-painted samples respectively. The negative effect of painting is mainly due to the barrier effect of the paint that prevents microorganisms from converting organic components of the biopolymer into water, CO2 and compost. Keywords: biodisintegration; composting; painted; bioplastic; waste

In order to investigate the pyrolysis characteristics and mechanism of moso bamboo, its pyrolysis behaviour has been investigated by thermo-gravimetric analysis (TGA), which can be described as four steps: dehydration, hemicellulose pyrolysis, pyrolysis of cellulose and lignin, and residue decomposition. The decomposition of hemicellulose, cellulose and lignin are the main contributions for pyrolysis weight loss. Furthermore, the pyrolysis mechanism has been clarified based on pyrolysis kinetics model fitting. Detailedly, the pyrolysis kinetics of hemicellulose agrees with first order chemical reaction, whereas the pyrolysis kinetic equation of cellulose and lignin accords with the 1D-diffusion parabolic curve. And the apparent activation energy of them is 124.62 and 232.64 KJ/mol, respectively. Keywords: Moso bamboo, pyrolysis characteristics, pyrolysis kinetics, thermo-gravimetric analysis

The paper presents the results of compressive tests performed on Biomet® orthopedic bone cement currently used in arthroplasty. By direct molding of the cement, cylindrical test specimens were manufactured with cross section diameter of 6 mm and height of 12 mm. The stress–strain curves of all specimens tested exhibited similar linear elastic regime with a local maximum followed by yielding. The average compressive strength of the samples is 91.55 MPa, while the average modulus of elasticity was calculated at 1483 MPa. The obtained results can be used in order to asses the fatigue life-time of this type of bone cement. Keywords: total hip replacement, bone cement, PMMA, compression, elastic modulus, Poisson’s ratio