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In order to assess in vitro biomechanical behaviour of dental implants, numerous experimental methods can be used. In our experiment, we use dental implants inserted into the artificial jaws, made of ABS plastic material and Araldite D, and we chose the VIC method (Video Image Correlation), spatial version (3D), to monitor the deformation field of area surrounding implant. For both experiment types, with ABS mandible or Araldite D sheet, the results were similar and controllable. Authors are confident with this technique and hope that experimental methods will serve as a database for research in this area. Keywords: dental implants, biomechanics, ABS, Araldite D

Hybrid inorganic/organic films composed of an polyoxometalate (POM) (iron(III)-trisubstituted Keggin polyoxomolybdates, PFe3Mo9) and a non-conducting polymer [(poly(ortho-phenylenediamine)) or a conducting polymer (poly(1,8-diaminonaphtalene)) were synthesized by electropolymerization from aqueous solution on the surface of a graphite electrodes. Cyclic voltammetry gave evidence of a redox behaviour of the PFe3Mo9, irrespective of the type of polymer used for POM immobilization into the composite matrix. Keywords: polyoxometalate, electropolymerization, hydrogen peroxide, glucose

Renal parenchyma is served by a complex vascular-ductal system formed by renal artery (RA), renal vein (RV) and the pyelocaliceal system (PCS) continued by ureter. In the training of medical students and residents, the study of the interrelations of the elements of intraparenchymatous branches of the RA, RV tributaries, and PCS, as well as the analysis of renal corrosion casts is superior because it allows simultaneous analysis of the three vascular-ductal systems of the kidney. The present study examines the most favourable order of plastic mass injection for obtain good quality renal corrosion casts. There were used 36 kidneys from 18 domestic pigs, divided into three groups, to whom the vascularductal elements were injected with plastic (Technovit 7143), with different order of injection: the first group - with injection in order: PCS, RV and RA; the second group - with injection in order: PCS, RA and RV; the third group - with injection in order: RA, RV and PCS. Most affected by vascular compression were the renal vein and its intraparenchymatous tributaries. The most favourable order of plastic mass injection for obtain good quality renal corrosion casts by ex-situ injection is: RA, RV and PCS. Keywords: corrosion casts, pig kidney; pyelocaliceal system; renal artery; renal vein; training

This paper presents our experiments on obtaining and characterizing polymeric composites based on wood sawdust and natural rubber. Natural rubber was crosslinked both through a classic method – using benzoyl peroxide at high temperature, and an unconventional method at room temperature – electron beam irradiation. Physico-mechanical properties such as hardness, modulus at 100% elongation and tensile strength indicate a significant improvement as a result of adding wood sawdust to blends. Better results have been obtained using crosslinking by electron beam irradiation. The crosslinking rates of samples, measured using the Flory-Rehner equation increase as the amount of wood sawdust in blends increases and as the electron beam irradiation dose increases. The swelling parameters of samples significantly depend on the amount of wood sawdust in blends, because the latter has hydrophilic characteristics. Key-words: natural rubber, wood sawdust, irradiation, physico–mechanical characteristics, crosslink density, swelling parameters

The bond strength of the root canal sealers to dentin and core material seems to be a very important property for maintaining the integrity and the seal of root canal filling. This in vitro study aimed to evaluate and compare the bond strength of three different root canal sealers. Forty five extracted single-root human teeth were prepared using ProTaper system. Teeth were divided into three groups (n=15) for obturation using AH Plus, RealSeal and a new, experimental endodontic sealer containing hydroxyapatite. Each tooth was obturated using warm vertical condensation technique in the apical third and gutta-percha injection in the middle and coronal thirds of the root canal. All teeth were sectioned transversally at the apical and middle thirds into 1 mm thick discs. Push-out tests were performed using a universal mechanical testing machine (Lloyd Instruments – LR5k plus). The maximum load at failure was recorded and divided by the area to obtain the bond strength in MPa. Using a stereomicroscope (STEMI 2000 C Zeiss, Jena, Germany), at a magnification of 20x, the interface where the obturation failure occurred was identified. Statistical analysis was performed and the result showed non significant differences between the three endodontic sealers at each level obturation. Also, the stereomicroscopic analysis showed a good adhesion to dentin for all sealers. The experimental sealer adhesion is comparable to that of the two consecrated materials. Keywords: push-out test, bond strength, endodontic sealer, root canal obturation

Profiled steel sheeting dry board (PSSDB) consists of steel sheeting that are connected to a dry board using self-drilling and self-tapping screw to form a light composite structure. This study focuses on PSSDB that uses 12 M geopolymer concrete infill with half-sized dry-board infill (GPCHB). The detected weakness of the profiled steel sheeting on this PSSDB system is due to the relatively easy occurrence of local buckling on its structure as it reaches an ultimate load, especially on the top flange. This study aims to analyze the relationship between stiffness and deflection at the mid-span of PSSDB systems using different parameters. Results show that the panel with 12 M GPCHB has 107% and 40% increase in rigidity compared with those of the control (without infill) and full board normal concrete panels, respectively. Mid-span deflection is also reduced to 52%. In conclusion, stiffness increases and deflection decreases when 12 M GPCHB is used in the panel. Keywords: composite structure, geopolymer concrete, weakness, local buckling, stiffness

Film forming polymer solutions for skin wound dressing were developed and characterized. Film forming solutions were prepared by adding polyvinyl alcohol (PVA) and poly (hydroxy) urethane (PHU) in different proportions into a well tolerate volatile solvent. The formulations were in vitro evaluated according to five criteria. Two formulations have proved the ability to form polymeric film. Evaluation of the tensile strength, contact angle and swelling index were made for these formulations. The results showed a positive response of the formulations to be used for skin wound dressing. Keywords: integrity on skin, swelling index, tensile strength, surface polarity

The challenge of the chondral lesions treatment has been considerably answered with the development of non-cellular scaffolds. Among the most frequently used, the scaffolds based on Hyaluronic Acid and, respectively, collagen derived polymers are the subject of our comparative research. The present paper highlights some particularities related to their intrinsic physical properties such as adhesiveness, microstructure and cellular permeability and concludes that the two alternatives present qualitatively similar outcome and effectiveness. Keyword: hyaluronic acid polymer scaffold, collagen scaffold, chondral lesions, osteoarthritis

The mechanism of action and adverse reactions of 52 mg levonorgestrel-releasing intrauterine system and also level of pain during the insertion and techniques of anesthesia or analgesia for this procedure have been well documented. On the opposite pole the 13.5 levonorgestrel-releasing intrauterine system has been recently launched in Europe. To our knowledge there are no studies correlating the device design and biomaterials, mechanism of action, surgical technique and level of pain during the insertion of levonorgestrel-releasing intrauterine systems. This study was undertaken in order to determine whether there is a different level of pain during the insertion of 52 mg levonorgestrel-releasing intrauterine system compared to 13.5 mg levonorgestrel-releasing intrauterine system, considering the mechanism of action and the structural and dimensional discrepancies between the two intrauterine devices. Keywords: Levorgestrel-releasing intrauterine systems, device design, mechanism of action, level of pain during the insertion

The liver segmentation is determined by the distribution of the vascular and ductal hepatic elements; from this, the hepatic portal vein (HPV), the central element of liver afferent pedicle, is the most important. The posterior branch (PB) is serving right lateral division (RLD) of the liver and presents the lowest morphological variability. On a total of 125 pieces of liver corrosion casts, one examined the intraparenchymal distribution of portal PB and the segmentation of RLD. Regarding the intraparenchymal distribution of the branches in the RLD of the liver, we showed four distinct morphological types: Type I (77.6% of cases) in which the PB bifurcate symmetrically in branch of segments VI and branch of segment VII; Type II (8.8% of cases) in which the PB bifurcate in branch of segment VII and an inferior branch, that bifurcate branch of segment VI and branch of segment VIA; Type III 12.8% of cases) in which the PB bifurcate in branch of segment VI and a superior branch, that bifurcate in branch of segment VII and branch of segment VIIA; Type IV (0.8% of cases) in which the PB trifurcate in branch of segment VI, branch of posterior intermediate segments, and branch of segment VII. Knowledge of these morphological types of portal PB is important for clinical and surgical practice. Keywords: corrosion casts; hepatic portal vein; posterior branch; variability; morphological typologies