Materiale Plastice Vol 54, Issue 1

Volume 54, Issue 1

Published: March 2017 Articles: 41 Pages: 1 – 193
Research Articles
1 – 7
The Vibration Study of DAMMAR Based Composite Bars by Using a New Euler-Bernoulli Theory
Dumitru BOLCU, Marius Marinel STANESCU, Ion CIUCA, Cosmin Mihai MIRITOIU, Alexandru BOLCU, ROBERT CIOCOI
Open Access DOI: 10.37358/MP.17.1.4773
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Abstract: In the paper, a new Euler-Bernoulli theory is presented, in which the bars eigenpulsations with rectangular section increase with the ratio between the bar width and thickness. This theory is experimentally verified for composite bars made of Dammar reinforced with cotton and flax plus one or two layers of fiber glass fabric. For the considered bars, we have experimentally determined the eigenfrequencies and the damping factor values. We have experimentally determined the Young modulus and breaking strength for the used resin and the obtained composites.
8 – 13
Development and Characterization of Novel Freeze-thawed Polyvinyl Alcohol/ Halloysite Hydrogels. An approach for drug delivery application
Adi Ghebaur, Sorina Alexandra Garea, Sergiu Cecoltan, Horia Iovu
Open Access DOI: 10.37358/MP.17.1.4774
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Abstract: The influence of aluminosilicates on the structure and drug release profiles of polyvinyl alcohol (PVA) – halloysite (HNT) hydrogels containing acetylsalicylic acid (ASA) as a model drug was monitored. The hydrogels were synthesized using a three cycle freeze – thawing procedure and were characterized by FTIR, XRD and SEM. The swelling degree and cytotoxicity were also determined. All hydrogels properties were influenced by HNT concentration from the polymer matrix. The release of ASA, from PVA – HNT hydrogels was monitored in the gastrointestinal tract conditions.
14 – 17
Polymeric Membrane for Verteporfirin Purification
Stefania Simionescu, Sofia Teodorescu, Rodica Mariana Ion, ELENA VOICILA, Gheorghe Nechifor
Open Access DOI: 10.37358/MP.17.1.4775
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Abstract: Verteporfirin is the active substance of the medicine Visudyne (the basic form porphyrin of the medicine) approved and in use for ophthalmic diseases and tumor types. Because the informations from literature about degraded of this porphyrins are greatly reduced, we propose in this paper to separate the different degraded forms of this porphyrin by using polysulfone membrane polymer type. In this paper are presented some analytical results of verteporfirin before and after passing degraded form of the porphyrins over these membranes.
18 – 21
Recovered Polypropylene Composites with High Impact Strength
PAUL GHIOCA, LORENA IANCU, RAMONA MARINA GRIGORESCU, BOGDAN SPURCACIU, MARIA RAPA, CORNEL CINCU, et al.
Open Access DOI: 10.37358/MP.17.1.4776
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Abstract: This paper presents a modification study of recovered polypropylene by melt alloying with a styrene-isoprene block-copolymer blend, thus ensuring the optimum conditions to obtain polypropylene composites with performance impact strength.
22 – 28
New Solvent-free Polyurea Binder for Plastic Pyrotechnic Compositions
Gabriela TOADER, Traian ROTARIU, Edina RUSEN, Jeremie TARTIERE, Sorin ESANU, Teodora ZECHERU, et al.
Open Access DOI: 10.37358/MP.17.1.4777
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Abstract: The paper describes the investigations related to the fabrication and characterization of two new plastic pyrotechnic compositions using solvent-free polyurea as binder. These solvent-free polyurea binders allow wet or dry pressing of the pyrotechnic compositions. The rubbery texture of the polyurea binders minimize the risks associated to the dry pressing of other brittle binders. A comparative theoretical and experimental study between these new types of binders and a conventional binder has been performed, in order to establish the improvements that could be brought to the pyrotechnic compositions, in terms of safety and performance.
29 – 31
3D Printing of a Mandibular Bone Deffect
ALIN GABOR, TIBERIU HOSSZU, CRISTIAN ZAHARIA, ALEXANDRU KOZMA, ANDREEA CODRUTA COJOCARIU, MEDA LAVINIA NEGRUTIU, et al.
Open Access DOI: 10.37358/MP.17.1.4778
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Abstract: The aim of this study was to achieve a polymeric scaffold, ex-vivo, using 3D printing technology and then subjecting it to various tests to check its optimal property. Initially there was selected a lower jaw with a bone defect that would have prevented any treatment based prosthetic implant. The mandible was first scanned using an optical scanner (MAESTRO DENTAL SCANNER MDS400). The scanning parameters using optical scanning system are: 10 micron accuracy, resolution 0.07 mm, 2 rooms with High-Resolution LED structured light, two axes. The scan time of the mandible was 4-5 min. Later the same mandible was scanned using CBCT’s CRANEX 3DX. The images obtained using CBCT’s were correlated with those obtained by optical scanning. Further on, there was achieved the digital design of the future scaffold with the conventional technique of wax addition directly on the mandibular bone defect. After that, this was again scanned using scanning system MAESTRO DENTAL SCANNER MDS400, and using CBCT’s CRANEX 3DX. The images obtained were correlated with all the scanned images of original mandible bone defects. There were made two polymeric scaffolds using 3D printing system an (D20 Digital Wax System 3D Printer). After printing, scaffold sites were introduced for 30 minutes in an oven curing. Later the pieces obtained were processed to remove small excesses of work. There were obtained 3 blocks of polymers that have a good adaptation to the bone profile. Often, in oral implantology and maxillofacial surgery appear bone defects. They prevent an optimal treatment of bio-functional and aesthetic restoration. Using 3D printing technology one can achieve scaffold sites of different biocompatible materials that have optimal properties to replace bone defect and restore the defective area. These scaffold sites have an intimate adaptation to the defect. 3D printing techniques used to restore bone defects can quickly and efficiently give the possibility to have a successful implantology prosthetics treatment.
32 – 36
The Advantages of High-density Polymer CAD/CAM Interim Restorations in Oral Implantology
CLAUDIA FLORINA ANDREESCU, DOINA LUCIA GHERGIC, OANA BOTOACA, HORIA MIHAIL BARBU, IOAN SEBASTIAN CERNUSCA MITARIU, DAN NICOLAE PATROI
Open Access DOI: 10.37358/MP.17.1.4779
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Abstract: Fabrication of temporary restorations is an essential part in dentistry and especially in oral implantology. Polymethyl methacrylate is used for a long time as material for temporary restorations and many improvements has been done to increase its properties, especially fracture resistance. Crosslinking and computer-assisted design/computer-assisted machining permit fabrication of long-term temporary restorations with flexural strength high enough and good modulus of elasticity that do not fracture easily under functional loads.
37 – 40
The Use of Hyaluronic Acid Combined with Teosyal Redensity II for the Treatment of Dark Circles Under the Eyes
Valeriu Ardeleanu, Sorin Ioan Berbece, Ioan Petre Florescu, Radu Cristian Jecan
Open Access DOI: 10.37358/MP.17.1.4780
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Abstract: This study intends to highlight the results of the product Teosyal Redensity II through the cumulative effects of its constituents, that have an antioxidant, hydrating, filling and facial restructuring role. The study was performed in the Arestetic Clinic, Galai, between 07.12.2015 and 07.12.2016 on a group of 49 patients, of which 43 women and 6 men. Teosyal Redensity 2 proved to be a safe product – as long as it is injected correctly, it does not cause complications. It’s easy to inject and has a very high efficiency. It’s a periorbital rejuvenation and restructuring product, with a filling, antioxidant, hydration and dermal redensification effect. In the case of persons that needed a second injection after 1 month, one could observe a major improvement in elasticity and firmness felt by the person performing the injection. The injection requires small quantities of the substance and is accompanied by only mild discomfort. The result is visible right away.
41 – 44
Polymeric Composites Based on Polyurea Matrix Reinforced with Carbon Nanotubes
Maria Adina Vulcan, Celina Damian, Paul Octavian Stanescu, Eugeniu Vasile, Razvan Petre, Gheorghe Hubca
Open Access DOI: 10.37358/MP.17.1.4781
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Abstract: This paper deals with the synthesis of polyurea and its use as polymer matrix for nanocomposites reinforced with multi-walled carbon nanotubes (MWCNT). Two types of materials were obtained during this research, the first cathegory uses the polyurea as matrix and the second one uses a mixture between epoxy resin and polyurea. The nanocomposites were characterized by Thermogravimetric Analysis (TGA), Dynamic Mechanical Analysis (DMA), Scanning Electron Microscopy (SEM) and Tensile Tests .The elastomeric features of nanocomposites were highlighted by the results which showed low value of Tg. Also higher thermal stability with ~40oC compared with commercial products (M20) were observed, but lower mechanical properties compared to neat polyurea.
45 – 47
Influence of the Fiber Post Material on the Reconstructed Tooth Crown Bending Resistance
MONA IONAS, ALEXANDRU PAUN, MARCU FRATILA
Open Access DOI: 10.37358/MP.17.1.4782
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Abstract: Post and core build-ups provide resilience and retention for future tooth restorations. In this study we intend to assess the resistance to fracture of two types of aesthetic post, using a testing machine after the application of a paraxial force. The results show that no specific material from the ones used shows a better behavior. Fiber quartz posts AAA Fiber Post had the highest resistance and the fiberglass posts Matrix Plus 2 were rated with the lowest values. Further laboratory and clinical studies are necessary to the in which one type of post material is favorable for a specific type case.
49 – 52
Evaluations of Implanted Polypropylene Mesh After Surgical Removal Due to Eventration or Mesh Rejection
Bogdan Stelian Mastalier Manolescu, Valentin Popescu, Marius Septimiu PetruTescu, Andrada Serafim, Izabela Cristina Stancu
Open Access DOI: 10.37358/MP.17.1.4783
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Abstract: The Gold standard in parietal wall hernias is represented by mesh implantation. Both wall repair and hernia-associated complications are related to the anatomic location and biomechanics of the structures involved specificity. This work reports the results of the intraoperative and postoperative evaluation of synthetic polypropylene mesh integration. The mesh and the surrounding tissue, previously removed and preserved, have been analyzed macroscopically and at microscopic level. The tissue invaded the pores of the mesh and coated the monofilaments. The right balance between the mesh type and tissular response is hard to evaluate preoperatively, due to individual variations, but we can upgrade the criteria used to personalize the treatment for the best possible outcome.
53 – 55
The Management of a Plastic Instrument. The way from idea to patent and final product
Stefan Lucian BURLEA, Anamaria CIUBARA, Georgeta BURLEA, Ramona CIMPOESU
Open Access DOI: 10.37358/MP.17.1.4784
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Abstract: The article presents the procurance of an apparatus intended for the stage of reading and writing , used both by the pre- school children and the persons who present speaking deficiencies ,obtained from plastic parts marked and processed using a laser equipment. The learning equipment of writing and reading consists in a carcass of a triangular prism which has on a lateral side two visualization windows and a magnetic plate for writing, placed one below the other, at an appropriate distance, each visualization window being equipped with several illumination sources, disposed in a lineal way along the window, having an independent performance.
56 – 59
Nano Filler Composite Restorations Marginal Adaptation. Direct and indirect assessment
Cristian Ratiu, Adrian Almasi, Anca Porumb, Alexandrina Muntean
Open Access DOI: 10.37358/MP.17.1.4785
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Abstract: Marginal adaptation at composite enamel interface was assessed through direct clinical method, three-dimensional scanning and optical microscopy respectively for three composite materials with Nano filler: Tetric EvoCeram® (Ivoclar Vivadent-), Premise™ (Kerr Corp.) and experimental material C20 (“Raluca Ripan” Chemistry Research Institute, Cluj-Napoca). Clinical evaluation of marginal adaptation highlights at 6 months and at 12 months a rate of 25-40% marginal defects, regardless the Nano composite material used. Characterisation of interface between Nano-composite material and dental tissue requires a complex multifactorial assessment.
60 – 62
SEM Analysis of Composites with TCP/HA/Chitosan/Poly (Methylmethacrilate)
Ileana Cojocaru, Doina Prodan, Violeta Popescu, Marioara Moldo
Open Access DOI: 10.37358/MP.17.1.4786
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Abstract: Modified cement composites were prepared by dispersing commercially available PMMA powders and chitosan/ tricalcium phosphate (TCP) or chitosan / hydroxyapatite (HA) fillers into a PMMA matrix. SEM and EDX were used to determine the compounds and the morphology of the composite. The characteristics of these materials indicate that the addition of chitosan/TCP and chitosan /HA as a constituent into the PMMA cement significantly decreases the curing peak temperature. Furthermore, the setting time increases from 4 min to 7 min, as compared to the PMMA cement. These changes could be beneficial for the handling of the bone cement paste and causing less damage to the surrounding tissues.
63 – 66
Studies and Research on the Electrical Resistance of the Polyethylene Insulation Used for the Chemical Protection of the Steel Pipelines Intended for the Natural Gas Distribution
Stefan Mihai Filip, Razvan George Ripeanu, Eugen Avrigean
Open Access DOI: 10.37358/MP.17.1.4787
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Abstract: The paper aims to find solutions to some of the problems the staff operating the natural gas networks have to face, which are the low, medium and high pressure, and the corrosion of the steel pipelines. This metal corrosion can be dealt with by insulating it through various procedures, the latest being the different thickness polyethylene strips insulation. The goal of the paper is to observe the insulation areas on the pipeline which can be destroyed by mechanical factors during operation and the method of remedying these faults with high density polyethylene strips.
67 – 72
Mechanical Properties and Fatigue Performances on Sandwich Structures with CFRP Skin and Nomex Honeycomb Core
Sebastian Marian ZAHARIA, Mihai Alin POP, Augustin SEMENESCU, Bogdan FLOREA, Oana Roxana CHIVU
Open Access DOI: 10.37358/MP.17.1.4788
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Abstract: Composite sandwich structures with Nomex honeycomb core are commonly used in industrial applications. This paper was focused on the study of the mechanical properties of sandwich structures with CFRP (carbon fibre reinforced polymer) skin and a phenolic resin-impregnated aramid paper core, known as Nomex. The paper analyzes behaviour and determines the mechanical properties of the CFRP-Nomex specimens to different types of tests, such as: three - point bending, compression, impact. The exceptional fatigue resistance of the composite structures is responsible for their success in a variety of industrial applications. For this reason, in this paper were implemented accelerated testing techniques for CFRP-Nomex sandwich structures, resulting in a significant reduction of the test time (of 13.9 times). The main indicator that was determined using the accelerated testing methodology was the mean life that has value of 268554 cycles.
73 – 78
Influence of Plasticizers Over Some Physico-chemical Properties of PLA
MARIA RAPA, RALUCA NICOLETA DARIE NITA, CORNELIA VASILE
Open Access DOI: 10.37358/MP.17.1.4789
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Abstract: The use of polylactic acid (PLA) for food packaging is limited because it has poor mechanical and thermal properties, low ductility, and its oxygen barrier property is quite poor compared with polymers obtained from petrochemical resources. One main task of processors is to modify these properties in such a way that PLA to be able to compete with conventional polymers such as polyethylene, polypropylene or poly(vinylchloride). Our studies were conducted to test the effect of different types of plasticizers on the PLA melt processing and also on its mechanical and thermal performance.
79 – 82
Implantarea componentelor protetice axata pe planningul radiologic in diformitatile genunchiului in valgus
Liliana Savin, Olivera Lupescu, A. Patrascu, D. Mihailescu, V. Grigorescu, T. Zlate, et al.
Open Access DOI: 10.37358/MP.17.1.4790
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Abstract: The present study evaluates the radiologic particularities of deformities in valgus that are necessary for a correct positioning in frontal and rotational plane of the prosthetic components and for a long term life of the polyethylene and the prosthetic implant. Long leg X-ray performed in orthostatism can evaluate the type and degree of the deformity in frontal plane, it can establish the osteotomy cuts and the necessity of ligament release. The anterior-posterior radiologic incidence of the knee in flexion of 900 evaluates the individual rotational profile by calculating the torsion of the distal femoral. Although the frequency of deformity in valgus is more reduced, it presents important clinical and radiologic particularities for the surgical technique.
83 – 87
Silk Fibroin Films Decorated with Magnetic Nanoparticles for Wound Healling Applications
Mihaela Cristina Bunea, Eugenia Vasile, Bianca Galateanu, Ariana Hudita, Mirela Serban, Catalin Zaharia
Open Access DOI: 10.37358/MP.17.1.4791
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Abstract: The paper is focused on designing a novel silk fibroin-magnetite biomaterial scaffold for wounds healing in terms of: synthesis, physico-chemical and morphological characterization and in vitro biological behaviour assessment. Magnetic scaffolds were prepared from silk fibroin solutions and magnetic nanoparticles with various concentrations by solvent casting technique. Specimens were investigated by FTIR-ATR spectroscopy and XRD measurements. Morphological investigation including internal structure was employed by AFM and TEM/HRTEM analyses. Biological assay was performed on human adipose derived stem cells isolated from subcutaneous adipose tissue. Results suggested that all the tested magnetic silk-magnetite scaffolds display a good biocompatibility in vitro on hASCs and could be promising candidates for further wound dressing testing.
88 – 90
Use of Trichloroacetic Acid in Treating Facial Hyperpigmentation
Radu Cristian Jecan, Alexandru Nicolau, Ioan Petre Florescu, Valeriu Ardeleanu, Sorin Berbece
Open Access DOI: 10.37358/MP.17.1.4792
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Abstract: This paper aims to present the benefits and results of using TCA of high concentration of 50%, in conjunction with the presentation of adverse reactions and complications. The study was conducted in Arestetic Clinic Galai during the period 10 Dec. 2015-1 Nov. 2016, on a group of 12 patients, of which 10 women and 2 men. The product used was Easy TCA 50% manufactured by SkinTech laboratories. Three coats of TCA were applied at intervals of 4 minutes each. The end result was assessed at 21 days, when the entire surface of the skin was peeled and re-epithelized. Patients were asked to assess the degree of satisfaction on a scale of 1 to 10, with 1 being the least satisfactory and 10 being the most satisfactory. As a result of this assessment, 10 patients rated the degree of satisfaction with 10 (83%) and 2 patients rated the degree of satisfaction with 9 (17%), with an average degree of satisfaction of 9.83. At 21 days, dyschromias and hyperpigmentations completely disappeared in 9 patients, while a female patient and 2 male patients still presented with barely noticeable spots. These three persons were subjected to the second peeling after 2 months, this time in two layers, and these hyperpigmentations disappeared at the end.
91 – 97
Effect of Unmodified and Modified Nanocrystalline Cellulose Reinforced Polylactic Acid (PLA) Polymer Prepared by Solvent Casting Method Morphology, mechanical and thermal properties
Siti Norbaya KASA, Mohd Firdaus OMAR, Mohd Mustafa Al Bakri ABDULLAH, Ismarul Nizam ISMAIL, Sam Sung TING, Sebastian Calin VAC, et al.
Open Access DOI: 10.37358/MP.17.1.4793
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Abstract: The positive attributes of excellent biocompatibility and biodegradability of biocomposites with the addition of versatile nanocellulose from agriculture wastes have provided plenty opportunities for further development of functional biocomposite in various fields. Therefore, solvent casting was selected as a reinforcement method in order to produce biocomposite comprise of nanocrystalline cellulose and PLA polymer. Modification of nanocrystalline cellulose through acetylation reaction was conducted upon reinforcement to reduce its surface polarity and hidrophilicity. Biocomposite films prepared at various unmodified (uNC) and acetylated nanocrytalline cellulose (aNC) loading were exposed to morphological (FESEM), tensile test and thermal analysis (TGA). Reinforcement of aNC shows a better dispersion in PLA polymer due to the decreasing of surface polarity, thus increasing inter-facial interaction between both materials. This is proven by greater performance of biocomposite films in tensile strength, Young’s modulus and thermal stability of aNC reinforced PLA as compared to uNC reinforced PLA. Overall, it can be concluded that these research findings can widen the scope of biocomposites research area and have significant implications for the commercial application of biomass products.
98 – 102
Biomaterials: Polylactic Acid and 3D Printing Processes for Orthosis and Prosthesis
Roxana Miclaus, Angela Repanovici, Nadinne Roman
Open Access DOI: 10.37358/MP.17.1.4794
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Abstract: Since the development of 3D printing, over the past decades, the domain of application has evolved significantly! Concerning the orthosis and prosthesis manufacturing, the 3D printing offers many possibilities for developing new medical devices for people with disabilities. Our paper wish to synthetize the main 3D printing methods and the biomaterial properties which can be used in orthosis and prosthesis manufacturing, like polylactic acid or acrylonitrile butadiene styrene. Fused Deposition Modeling and Stereo lithography are most used for medical devices manufacturing and usually using polylactic acid, considering the properties of this polymer and de organic componence.
103 – 110
pH Sensitive Polymeric Binders for Energetic Materials
ANDREEA ELENA VOICU, TRAIAN ROTARIU, MIRCEA TEODORESCU, TEODORA ZECHERU, TUDOR VIOREL TIGANESCU, OCTAVIAN ORBAN
Open Access DOI: 10.37358/MP.17.1.4795
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Abstract: The aim of this research has been to develop a new generation of eco-friendly binders, soluble at alkaline pH, which could allow facile recovery of explosive fillers without using organic solvents, while maintaining their chemical and physical characteristics. For this purpose, “smart” polymeric binders are to be designed based on acrylic acid and other acrylic monomers. In this view, theoretical and experimental studies have been performed in order to establish which synthesized polymer is adequate for the desired application.
111 – 115
The Influence of Cervical Cavity Shape on the Restoration Material Retention. A finite element method study
ANAMARIA FLORESCU, STEFAN MANEA, VIOLETA HANCU, ROXANA MANU, CORNELIA FLORENTINA BICLESANU
Open Access DOI: 10.37358/MP.17.1.4796
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Abstract: Present study examines, by means of finite element method, the influence of cervical cavity shape on tensions distribution caused by occlusal overload of the teeth with abfraction lesion. Same force values are applied to four 3-D lower premolar finite element models, representing four different cavity shapes. An extracted lower premolar which presented an abfraction lesion has been used. The restoration was achieved by using ER adhesive systems and Giomers. The premolar was scanned and the resulting sections were processed and converted into a 3D digital format. Thus, a model of finite elements which presented a restored wedge-shaped cavity in the cervical dental area was obtained. Then, by modifying the shape and dimensions, there were created another 3 modified-shape cavities. Forces of different magnitudes (45-150N), exerted at a 45 degree angle on buccal cusp, have been applied. A wedge-shaped cavity with a short occlusal side does not show tension in the cervical region, nor in the distal angle of the restoration up to a force of 100N. So, in order to increase the retention of the abfraction restoration, changing the shape of the cavity could be the treatment of choice. Clinical relevance In order to avoid costly and unethical research, by means of FEM, different shapes of cervical cavities were easily created and conditions that influence retention of abfraction restoration were tested.
116 – 118
Comparative Study on the Effect of Three Disinfection Procedure on the Streptococcus pyogenes Biofilm Formed on Plastic Materials Used in Paedodontics and Orthodontics
ALEXANDRU SIMION OGODESCU, ALEXANDRU ATTILA MORVAY, ADRIANA BALAN, LAURA GAVRILA, ANA PETCU, CARMEN SAVIN
Open Access DOI: 10.37358/MP.17.1.4797
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Abstract: Plastic materials are widely used today in Paedodontics and Orthodontics for manufacturing preventive and therapeutic devices. Since these are worn for long times in the oral cavity biofilm forms on the smooth acrylic surfaces of those appliances. The biofilm must be removed not to destroy the oral microbiology. The aim of this study was to research the possibility of removing the microbial biofilm and disinfecting retainers using the photodynamic effect of toluidine blue O, Fotosan System (CMS Dental, Copenhagen, Denmark) in comparison to two products available on the market Corega Denture Cleanser Tablets (GlaxoSmithKline) and the Retainer Brite® Cleaning Tablets (DENTSPLY International Raintree Essix, FL, USA). The plastic material used in this experiment was the cold-cure acrylic Palapress® vario (Heraeus-Kulzer GmbH, Hanau, Germany). Images of the biofilm formed by Streptococcus pyogenes were obtained using a confocal laser scanning m icroscope. The images were analyzed using Comstat 2 software. The results showed that all the three investigated methods had a disinfectant effect. Corega Denture Cleanser Tablets reduced most of the biofilm formed on the plastic substrate.
119 – 121
Textile Polypropylene Allografts and their Postoperative Tissue Reaction in the Surgery of Inguinal Hernia
DAN BRATU, ADRIAN BOICEAN, CIPRIAN TANASESCU, CIPRIAN SOFARIU, ALIN MIHETIU, IOAN SEBASTIAN CERNUSCA MITARIU, et al.
Open Access DOI: 10.37358/MP.17.1.4798
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Abstract: The usage of prosthetic devices in the surgery of parietal defect is, nowadays, essential for a good abdominal wall recovery and prevention of the hernia recurrence. A good and suitable textile allograft should poses one or more, ideally all, of the following characteristics: pliable, strong, non-allergenic and with perfect tissue integration behavior. The aim of this paper is to evaluate the immediate and long term tissue reaction of different textile allografts used in open surgery of inguinal hernia repair.
122 – 124
In vitro Assessment of Calcium Hydroxide Removal from Endo Blocks by Simple Irrigation with NaOCl and the Passive Ultrasonic Irrigation Technique
Alexandru Vlasa, Carmen Biris, Luminita Lazar, Anamaria Bud, Eugen Bud, IOAN Sebastian Cernusca Mitariu, et al.
Open Access DOI: 10.37358/MP.17.1.4799
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Abstract: Because endodontic pathology is caused due to bacterial contamination of the root canal system, endodontic treatment should focus on eliminating microorganisms in root canals. For more than 70 years Calcium Hydroxide has an important role in antimicrobial endodontic therapy. The use of calcium hydroxide is limited by the incomplete removal thereof, a residue covering 20% to 45% of the ductal wall, even after irrigation with NaOCl or EDTA. This study aims to evaluate the removal of calcium hydroxide in root canals using two different techniques.
125 – 128
Epoxy Composites Based on Resins Having High Flexibility Reinforced with Functionalized Carbon Nanotubes
Magdalena Adriana Ladaniuc, Gheorghe Hubca, Raluca Gabor, Cristian Andi Nicolae, Elvira Alexandrescu, Teodor San
Open Access DOI: 10.37358/MP.17.1.4800
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Abstract: The present paper was aimed at achieving a study on carbon nanotubes-reinforced composites and involved obtaining and characterization of composites based on epoxy compounds modified with hydroxyl groups-containing compounds (glycols). In order to obtain high flexibility epoxy resins-based composites, carboxyl- functionalized MWCNTs were used as filler at a concentration of 0.5 %. The influence of the weight concentration in CNTs on the mechanical and thermo -mechanical properties of the epoxy compounds was evaluated in comparison to mechanical properties of the DGEBA standard composites reinforced with 0.5 % MWCNT.
129 – 132
Evaluation of Sealing Materials Adhesion to Enamel An in vitro study
ANDREEA SIMONA POP, RADU SEPTIMIU CAMPIAN, MARIANA PACURAR, ELINA TEODORESCU, OLIMPIA BUNTA, VIORICA TARMURE
Open Access DOI: 10.37358/MP.17.1.4801
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Abstract: Sealing the pits and fissures of posterior teeth represents a local and specific method of caries prevention. The aim of this study was to evaluate the adhesion of two materials used in sealing pits and fissures: Pitt and Fisure and Fissurit FX (Voco), with the help of the scanning electronic microscope (SEM). The results of the study revealed a much higher quality of the Fissurit FX (Voco) product both in terms of adhesion to the enamel and material homogeneity. The Pitt and Fisure product showed a high degree of detachment from the enamel, marginal infiltration, large particles and a high concentration of inorganic particles.
133 – 136
Biochemical Markers Predicting the Risk of Gestational Diabetes Mellitus
BOGDAN ANDREAS SCHAAS, SABINA IVAN, MONICA TITIANU, CATALIN PLESA CONDRATOVICI, ADRIAN MAIER, CARMINA MIHAIELA SCHAAS
Open Access DOI: 10.37358/MP.17.1.4803
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Abstract: Gestational diabetes mellitus (GDM), defined by the occurrence or discovery of glucose intolerance during pregnancy is associated with higher risk of perinatal complications and long-term development of chronic diseases both in the mother and her child. Recent data suggest that women diagnosed earlier in pregnancy, even having more risk factors, develop fewer complications. The aim of the current study is to analyse biochemical markers that play a role in the pathophysiology of GDM and could lead to an early diagnosis. The authors performed a case-control study on 50 pregnant women that finally developed GDM and 50 pregnant women with risk factors for GDM which did non develop the disease. In all cases there were monitored a series of biochemical markers like glycated haemoglobin (HbA1c), sex hormone binding globulin (SHBG), magnesium (Mg), C-reactive protein (CRP), plasma insulin level, and pregnancy-associated plasma protein A (PAPP-A). All these factors were statistically analysed using univariate and multivariate tests in order to evaluate their predicting value. The combination of traditional risk factors with HBA1c, SHBG, PAPP-A and CRP proved significant prognosis value (75% sensitivity rate, 9% false positive rate) for GDM. In conclusion, these four biochemical markers available in early pregnancy have improved the performance of predicting models concerning the development of severe GDM needing insulin treatment and predisposing to maternal and foetal complications.
137 – 140
Clinical and Biochemical Study of Hypoandrogenic Metabolic Syndrome in the Cardiovascular Risk Content of Male Patients
ANA MINODORA GROZDAN, OANA PADURARU, RODICA GHIURU, COSTINELA GEORGESCU, LETITIA DUCEAC
Open Access DOI: 10.37358/MP.17.1.4804
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Abstract: The aim of this study was to determine the incidence of hypoandrogenenic to male patients with S.Met., in the context of cardiovascular risk factors. It performed description of a correlation with diagnostic components of S.Met., and specifying an interrelated male hypogonadism with each of the major cardiovascular risk factors.
141 – 144
Comparison of Shear Bond Strength and Adhesive Remnant Index of Brackets Bonded with Two Types of Orthodontic Adhesives
ELSAAFIN MAHMOUD, MARIANA PACURAR, EDWIN SEVER BECHIR, MARIUS MARIS, CRISTIAN OLTEANU, IONELA TEODORA DASCALU, et al.
Open Access DOI: 10.37358/MP.17.1.4805
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Abstract: The aim of this study was to evaluate shear bond strength and adhesive remnant index between two different brands of adhesive systems and brackets. The adhesive systems were represented by Opal Bond MV Composite and Opal Seal (Ultradent), respectively the fluoride releasing Transbond light cure adhesive paste and Transbond XT (3M). The utilised brackets were Avex metal bracket system (Ultradent), respectively Unitek™ Miniature Twin Metal Brackets (3M). The study was realized on 4 groups of extracted teeth: the first and second groups by using the products of the manufacturer Ultradent, respectively 3M, and the third and fourth groups by using the adhesive system of one manufacturer and the brackets of the other manufacturer. The study revealed that the use of adhesive system and brackets of the same manufacturer may increase the shear bond strength and decrease the adhesive remnant index.
145 – 154
Evaluarea liantilor geopolimerici activati alcalin ca alternativa la cimentul Portland
MEOR AHMAD FARIS, MOHD MUSTAFA AL BAKRI ABDULLAH, ANDREI VICTOR SANDU, KAHIRUL NIZAR ISMAIL, LIGIA MIHAELA MOGA, OANA NECULAI, et al.
Open Access DOI: 10.37358/MP.17.1.4806
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Abstract: This study summarizes the recent achievements in the development of alternative cement free binder materials (cementless) called alkali activated binder or more popularly known as geopolymers. The history of the development of alkali activated binder and recent terminology are discussed. The influence of the type of the base materials on the properties of goepolymers are thoroughly reviewed. The effect of composition and concentration of alkali and curing temperature on the properties and mechanical behavior of the resulting alkali activated material are discussed. Different type of base materials used in the formation of alkali activated material are blast furnace slag, metakaolin, fly ash, bottom ash, volcanic ashes, and red mud. The state-of-the art in this field demonstrated that this type of materials are ecologically friendly alternative of the Ordinary Portland cement.
155 – 159
Managing and Analyzing the Constructive and Functional Parameters on Fiberglass Custom Sensor Design for an Aerodynamic Balance
RADU CALIN PAHONIE, AMADO STEFAN, CARMEN LUIZA COSTULEANU, DANIEL BOLDUREANU, GABRIELA GLADIOLA ANDRUSEAC
Open Access DOI: 10.37358/MP.17.1.4807
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Abstract: An external three component strain gauge balance, designed, analyzed and manufactured in the Military Technical Academy is presented. The balance is a multi-piece type and employs the use of six custom-made load cells (sensors) to transfer the aerodynamic forces and moments from the wing to the computer software environment for data processing and analysis. The relations between the loads acting on the wing model and the measured forces are also underlined. The placement of the strain gauge on the composite laminate is an important issue for increased sensor precision; therefore, it is given a thorough analysis. The positioning of the force vector and its influence on the strain distribution over the lift sensor is also numerically and experimentally analyzed.
160 – 167
Polyelectrolyte Complex Based Nanocapsules Carrying Novel 5-Nitroindazole Thiazolidines with Potential Use in Treating Oral Infections
TONI ANDOR CIGU, MIHAELA NICOLETA HOLBAN, ANCA NICULINA CADINOIU, VALERIU SUNEL, CATALINA LIONTE, MARCEL POPA, et al.
Open Access DOI: 10.37358/MP.17.1.4808
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Abstract: The aim of this research was the synthesis of novel 2,3-disubstituted 1,3 thiazolidines, derived from 5-nitroindazole with antimicrobial activity and their encapsulation into polymer nanocapsules. Starting from previously synthesised hydrazones, there have been obtained novel thiazolidines by reaction with thioglycolic acid. The envisaged chemical structures were confirmed by spectral and elemental analysis. Two of the obtained thiazolidines were encapsulated into cationic Eudragit E100 nanocapsules, obtained by nanoprecipitation. In order to enhance drug release characteristics and particle stability, Eudragit E100 nanocapsules were covered with anionic polysaccharide (sodium alginate), thus forming a complex polyelectrolyte based membrane. The obtained nanocapsules presented a slower and more controlled drug release. The synthesized active principles, in free state and encapsulated into polymer nanocapsules, were tested for their acute toxicity and their influence on the development of model bacterial strains (Staphylococcus mutans, Actinobacillus actinomycetemcomitans, Bacillus subtilis, Bacillus cereus, Salmonella enteritidis, Escherichia coli and Staphylococcus aureus).
168 – 171
Fused Deposition Modeling Technology to Redesign a Nylon Component
NICOLETA ELISABETA PASCU, TIBERIU DOBRESCU, ADRIAN POPESCU, VICTOR GABRIEL ADIR
Open Access DOI: 10.37358/MP.17.1.4809
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Abstract: 3D printing by means of the Fused Deposition Modeling technology allows to obtain accurately and with very good results, plastic parts with various, simple or complex typo-dimensions and forms. The part in this article is from the field of road vehicles, it is called fixing clamp and it is of average complexity of the hole strip type with two protuberances necessary to ensure the purpose for which they provided. The necessity of making the part through addition appeared because it is not the market and because it was not provided by the supplier [1]. The constructive solution offered by the producer is a very good and necessary one, in the same time for the user in the equipment in which it is included (fig. 10). The constructive solution proposed in this article resulted from tests on some parts of Acrylonitrile-Butadiene-Styrene and Nylon and the results were conclusive for choosing and adopting the Nylon variant.
172 – 174
Chemical Senses Taste Sensation and Chemical Composition
CERASELA DORINA SINCAR, CAMELIA ANA GRIGORE, SILVIA MARTU, LILIANA LACRAMIOARA PAVEL, ALINA CALIN, ALINA PLESEA CONDRATOVICI, et al.
Open Access DOI: 10.37358/MP.17.1.4810
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Abstract: Taste and smell are chemical senses, which means that the receptors (chemoreceptors) of these senses respond to chemical stimuli. In order for a substance to produce a taste sensation, it should be ingested in a solution or subsequently dissolved in saliva; a solid substance put in the mouth perfectly dry is tasteless. Therefore, taste receptors or taste buds occur only on wet surfaces, more precisely in the oral cavity in land vertebrates; however, in aquatic animals, these receptors are scattered all over the body. There are functionally different types of receptors for each of the primary tastes and the distribution of each type is not even on the surface of the tongue mucosa. The sweet and sour sensitive buds are located mainly on the tip of the tongue, those sensitive to acids are located on the sides of the tongue and those stimulated by the bitter taste are located towards the back of the tongue and in the epiglottis area. Taste may be generated by substances which touch the taste buds through the blood; thus, histamine injected intravenously causes a metallic taste, glucin a sweet taste, whereas jaundice may trigger a bitter taste due to the big concentration of gallbladder constituents in the blood.
175 – 174
Clinical Personality Patterns in Young Adults with HIV Nosocomial Infection from the Region of Southeast Romania
MIRELA MODRIGAN, MIRUNA DRAGANESCU, CATALIN PLESEA CONDRATOVICI, LILIANA LACRAMIOARA PAVEL, ALINA PLESEA CONDRATOVICI
Open Access DOI: 10.37358/MP.17.1.4811
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Abstract: The study aim was to determine the characteristics and pervasive features of personality for the patients with nosocomial HIV infection and its influence on the adherence to antiretroviral therapy.The retrospective study was conducted on 123 patients with nosocomial HIV infection; for determining the characteristic and pervasive features of personality it was used MCMI-III test. The adherence to therapy was determined by using a questionnaire developed by the Department for monitoring HIV / AIDS infection of the National Institute of Infectious Diseases. The obtained results were compared with the data for the general population, published by DSM IV.28.5% of patients had disorders of personality traits, being significantly affected males rather than females (p = 0.0388). The most common personality disorder trait was the addiction. The compulsive type disorders (9.75%), avoidant, and histrionic (7.3% each) and narcissistic (4.9%) exceeded the prevalence recorded for the general population. Patients with disorders of personality traits had significantly reduced adherence to antiretroviral therapy (p = 0.0045).The patients with HIV nosocomial infection had those disorders of personality traits associated with the stigma and social rejection: dependence, avoidance, compulsiveness, and they influenced the attitudes towards therapy expressed by low adherence.
180 – 179
Finite Element Analysis of the Multilayered Honeycomb Composite Material Subjected to Impact Loading
RAUL CORMOS, HORIA PETRESCU, ANTON HADAR, GORGE MIHAIL ADIR, HORIA GHEORGHIU
Open Access DOI: 10.37358/MP.17.1.4812
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Abstract: The main purpose of this paper is the study the behavior of four multilayered composite material configurations subjected to different levels of low velocity impacts, in the linear elastc domain of the materials, using experimental testing and finite element simulation. The experimental results obtained after testing, are used to validate the finite element models of the four composite multilayered honeycomb structures, which makes possible the study, using only the finite element method, of these composite materials for a give application.
186 – 185
Forensic Expertise of the Paper Support of Counterfeit Documents
DANIEL POTOLINCA, IOAN CRISTINEL NEGRU, VIORICA VASILACHE, CECILIA ARSENE, MARIUS PADURARU, ION SANDU
Open Access DOI: 10.37358/MP.17.1.4813
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Abstract: The paperwork presents the results of the examination of the paper support from travel documents, by analysing the composition of the biodata page, which where differently falsified. For this purpose, the computer analyzed the composition of the tab, which is usually through various kinds counterfeit. By taking very small fragments of these pages, we can get useful information about the methods and techniques used by counterfeiters. The comparative analysis highlights the forgeries and certain connections with the original document. Therefore, there were obtained some data on their scientific investigation and highlighted the method used by forgeries.
190 – 193
Early Stratification of Sepsis Using Presepsine in Emergency Department (North-East of Romania Experience)
MARAIANA STUPARU CRETU, ANA CAMELIA GRIGORE, ADRIAN MAIER, TUDOR OVIDIU POPA, ALINA PLESEA CONDRATOVICI, CARMEN DOROBAT, et al.
Open Access DOI: 10.37358/MP.17.1.4814
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Abstract: Sepsiis syndrome is a common and have devastating implications on health care systems worldwide. Biomarkers may have an important role to highlight the presence, absence or severity of sepsis. Retrospective study was conducted on a group of 81 patients with suspected sepsis, presented in the Emergency Department - Emergency County Hospital St. Spiridon Iasi during 01.09.2014-30.10.2014. The obtained statistical data’s were interpreted using SPSS software and the ROC curve was calculated. The study aims was to establish the following: determining the validity of presepsin as a biological marker in sepsis diagnosis and prognosis; sepsis stratification. The mean age of patients was 64.52 years. Determination of presepsin sensitivity in sepsis early diagnosis was calculated by generating the ROC curve. Following AUC values were found: AUC = 0.709, with a standard error of 0.065 for predicting sepsis; AUC = 0.866, with a standard error of 0.080 for severe sepsis; AUC = 0.864, with a standard error of 0.053 in the presence of septic shock. The average values of presepsin, related with severity of infection, it was found to be 544.39 ± 141.93 pg./mL in case of localized infection; 605.6 ± 59.55 pg./ mL in patients with systemic inflammatory response syndrome; 1283.21 ± 195.74 pg./ mL in patients diagnosed with sepsis; 4787.8 ± 1980.43pg./mL in patients presenting severe sepsis and 3734.88 ± 1732.41pg./mL in patients diagnosed with septic shock. Presepsin level, measured by using quantitative dosage methods, may be helpful in staging patients diagnosed with sepsis and may be used as an indication for initiation of intensive therapy to prevent septic shock. Presepsin level can be used as an early marker of severe prognostic in septic patients.