Browse Articles

The present work reports on the biocompatibility of poly (3-hydroxybutyrate) and poly (3-hydroxybutyrate-co-3-hydroxyvalerate) loaded with bacterial cellulose and microcrystalline cellulose via melt processing. Biocompatibility was tested by physico-chemical and in vitro methods. Physico-chemical tests of biocomposites, such as reducing substances, acidity, alkalinity, absorbance by UV/VIS, residue on evaporation were performed on aqueous extract. The cell viability was evaluated by MTT assay. Cell morphology evaluation of cell culture treated with composites was visualized by light microscopy. Also, thermal properties of biocomposites were investigated by DSC analysis. The obtained results have shown good biocompatibility of all biocomposites. Keywords: biocompatibility, physico-chemical tests, cytotoxicity, melt processing

In this study were evaluated the chemical changes in enamel adjacent to four different composite resin restorations after their contact with hydrochloric acid. Twenty healthy molars were chosen for this study and class I cavities were prepared on occlusal surfaces. Four commercial composite resins were used for filling: Filtek Z250 (3M ESPE, USA), Filtek Ultimate (3M ESPE, USA), Herculite (SDS KERR, USA) and Point 4 (SDS KERR, USA). The samples were obtained by cutting the teeth in two halves. Some of the samples were maintained in distilled water as control group and the others were mentained for 30 min in 0,06 mol/L hydrochloric acid (pH = 1,2). The morphological aspect of the interface between enamel and composite resin was evaluated using scanning electron microscopy (SEM) and the mineral content (calcium, phosphorus, oxygen ions concentration) was assessed using EDX method. Chemical analysis showed significant changes of ions concentration both in enamel and in composite restorations. The enamel adjacent to Filtek Ultimate was less affected by the contact with hydrochloric acid when comparing to other composite resins. Keywords: gastroesophageal reflux disease (GERD), SEM microscopy, EDX method mineral content to enamel adjacent resin composite

Since most areas of dentistry deal increasingly with aesthetics, we conducted this study to evaluate the influence of perioral wrinkles on patients’ subjective assessment for their “beautiful smile” appearance before and after laser resurfacing. Thirty patients were included in the study. All selected patients had previously done reconstructive dental therapy. Prior to wrinkles resurfacing the following aesthetic analyses were performed:dentofacial aesthetic analysis beautiful smile and facial analysis for skin resurfacing using Fitzpatrick alternative classification system for degree of perioral wrinkles.The resurfacing was performed using Life Touch Er:Yag pulsed laser with Life Touch Aesthetic Peri-Oral Handpiece. The energy utilized in all patients ranged from 50 mJ at 10 pulses/sec. The analysis of patients’ degree of perioral wrinkles was performed as objective parameters which will influence the resurfacing outcome. The survey addressed patients’ satisfaction with regard to existing patient’s smile-“beautiful smile” in correlation with the presence of perioral wrinkles. The obtained data showed significant differences in individual assessment likeability versus that of the physician/examiner for appearance of the upper lip, incisal edge to lower lip and midline-relationship of central incisors to philtrum (p < 0.05). Individual likeability of upper lip appearance after resurfacing in correlation with the degree of perioral vary significantly depending on the degree of perioral wrinkles (Kruskal-Wallis H = 15.36, p = 0.005). Assessment concerning the personal likeability of the smile before and after treatment was tested with Wilcoxon Matched pairs test. The obtained results were statistically significant (p < 0.001). Keywords: beautiful smile, dental aesthetic, Er:YAG resurfacing, full mouth reconstruction

Tests on wearing clothes are complex methods of analysis that mainly consist of recording the physiological reactions in the body. An early supervision of these physiological reactions, at a physical charge and under certain climatic conditions, ergometrically shaped, provides precious information on the human body and its status, as well as on the worn clothes. Physical parameters of the environment and biometric parameters were measured during the wearing tests. There were tested 5 subjects, students, for wearing 5 textile garments. In the performed tests there were determined the following parameters: cardiac frequency, respiratory frequency and energetic consumption. Keywords: clothing, wear tests, warm environment, dynamic conditions, comfort, evaluation, biometric parameters

Domestic pigs were frequently used in training centers for residents and students in medicine for the stenting procedures at the level of renal arteries. On 12 domestic pigs (all male) with an average weight of 34 kg (30.0-39.9 kg), were analysed the morphological parameters of femoro-iliaco-aorto-renal arterial system. An analysis of the pelvic segment length (I-II-III) and abdominal (IV), shows almost perfect equality of the lengths of the two segments on the right (76.26 ± 5.30 mm / 76.21 ± 4.51 mm) and a mean difference of 1.25 mm in favour of segment IV (abdominal) (75.53 ± 5.10 mm / 76.78 ± 4.44 mm), a difference that correlate with left renal artery cranial origin. Pelvic diameter portions of femoro-iliac arterial axis increase linear in average by 10% per segment (from 3.99 ± 0.40 mm ± 4.89 in segment I at 4.89±0.33 mm in segment III). Increasing the diameter from the segment III to segment IV is approximately of 30%. The diameter of the proximal part of renal artery (3.46 ± 0.36 mm) on the studied material is smaller than the diameter of the proximal part of the external femoral artery (segment I) (3.99 ± 0.40 mm), making it easy retrograde catheterisation of femoro-iliac-aorto-renal arterial axis. Knowledge of the morphological parameters of femoro-iliaco-aortic arterial axis and their evolution in correlation with the weight of laboratory animals -domestic pigs- favours the achievement in good conditions to arterial catheterization for proximal renal artery stenting. Keywords: corrosion casts, domestic pigs; femoro-iliaco-aorto-renal axis; morphological parameters; stenting training

The purpose of this work was the detailed study of morphological biodegradation and the citotoxicity effect of some experimental biomaterials. The study has four experimental biomaterials based on polylactic acid, polyethylene glycol, tricalcium phosphate, chitosan and hydroxyapatite in different percent cured in air followed by heat treatment at 1200C. The experimental biomaterials were characterized by AFM (Multimode V-SPM, Veeco) and SEM (Q130 -FEI Company) microscopy. For the citotoxicity were used cell cultures of normal human fibroblasts and the viability testing was made with trypan blue. According to the experimental results, the biomaterial with highest percent in polylactic acid presents a high degradation, compared with the rest of the biomaterials which have HA in composition, who decrease this process. Fibroblasts cell culture showed good adhesion to the surface of the biomaterials. The viability of the biomaterials increases at 48h compared with 24h, which suggest the absence of the materials cytotoxicity. Our results sustain idea that biomaterials based on chitosan with additions can be successfully used for further studies in reparative medicine. Keywords: chitosan, biodegradable polymers, hydroxyapatite, SEM, AFM, citotoxicity

The paper aims at evaluating the impact of technological parameters of a drilling process on the parameter of surface roughness Rz (maximum height of roughness profile) of wood-based material (WPC – Wood Plastic Composite). During drilling with tools 3.0, 5.0 and 7.0 mm in diameter, the spindle speed nc and feed rate f were changed. The evaluation of statistical significance was performed using the ANOVA mathematical tool (two-way with repetition). Using a simple conversion, it is possible to assess which of the set parameters affects the final surface quality, which serves as supporting information for the work of an engineer. Keywords: statistical evaluation, composite, surface texture

In accordance with Terminologia Anatomica, the renal artery gives rise of two branches: anterior branch and posterior branch. Anterior branch gives rise to four segmental arteries: superior, anterior-superior, anterior-inferior and inferior; posterior branch continues with posterior segmental artery. On a total of 150 renal corrosion casts was examined the artery of inferior segment. Three morphological types have been highlighted: Type I, in which the inferior segmental artery originating directly in the trunk of the renal artery (8.0% of cases); Type II, in which the inferior segmental artery arises from the anterior branch of the renal artery (87.33% of cases); Type III, in which the inferior segmental artery arises from the posterior branch of the renal artery (4.67% of cases). In 33.33% of cases the inferior segmental artery arises independently from the trunk or renal artery branches (anterior or posterior). In 66.67% of cases, the inferior segmental artery realizes a common trunk with one or two other segmental arteries (in type II). Knowledge of these aspects is important both to investigate morphological imaging and preforming partial resection of the renal parenchyma. Keywords: kidney; corrosion casts; inferior segmental artery; variations

The aim of this study was to evaluate the role of local administration of vitamin D in influencing the rate of orthodontic tooth movement. Six dental arches were included in this study. Every arch was divided intro two hemiarches: experimental hemiarch and control hemiarch. The canines were included in this study. Control canines received orthodontic therapy compared with experimental canines which received orthodontic therapy associated with local administration of calcitriol (1,25 dihydroxycholecalciferol). The rate of tooth movement was measured in both hemiarches. We noticed a difference between the rates of orthodontic treatment in experimental and control hemiarches respectively. This might be attributed to local administration of calcitriol (1,25 dihydroxycholecalciferol). Keywords: bone remodeling, orthodontic tooth movement, vitamin D, bone desorption, bone apposition

Partial devulcanization of rubber crumb spent was performed in the presence of oxide nanoparticles. Nanoparticles on the basis of CaO and ZnO were prepared by dry grinding in a laboratory planetary mill and nanoparticles on the basis of Fe3O4 were obtained by precipitation. The distribution of particle sizes based calcium, zinc and iron were measured by dynamic light scattering. Devulcanization of the rubber crumb was carried out in a batch system at a temperature of 200°C and the sulfur content of rubber decreased more than 15 times after devulcanization. Homogeneity of bitumen, determined by fluorescence microscopy, was superior in case of modification with devulcanized rubber compared to the case of modification of bitumen with vulcanized rubber. Adhesiveness of bitumen road increases significantly after modification with desulfurized rubber compared to the case of bitumen modified with vulcanized rubber. Keywoords: waste, desulfurized rubber, bitumen modification, nanoparticles